/*
 * Copyright 2015-2017 Google, Inc
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * USB Power Delivery protocol stack.
 */

#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/usb/typec.h>
#include <linux/workqueue.h>

#include "pd.h"
#include "pd_vdo.h"
#include "pd_bdo.h"
#include "tcpm.h"

#define FOREACH_STATE(S)			\
	S(INVALID_STATE),			\
	S(DRP_TOGGLING),			\
	S(SRC_UNATTACHED),			\
	S(SRC_ATTACH_WAIT),			\
	S(SRC_ATTACHED),			\
	S(SRC_STARTUP),				\
	S(SRC_SEND_CAPABILITIES),		\
	S(SRC_NEGOTIATE_CAPABILITIES),		\
	S(SRC_TRANSITION_SUPPLY),		\
	S(SRC_READY),				\
	S(SRC_WAIT_NEW_CAPABILITIES),		\
						\
	S(SNK_UNATTACHED),			\
	S(SNK_ATTACH_WAIT),			\
	S(SNK_DEBOUNCED),			\
	S(SNK_ATTACHED),			\
	S(SNK_STARTUP),				\
	S(SNK_DISCOVERY),			\
	S(SNK_DISCOVERY_DEBOUNCE),		\
	S(SNK_DISCOVERY_DEBOUNCE_DONE),		\
	S(SNK_WAIT_CAPABILITIES),		\
	S(SNK_NEGOTIATE_CAPABILITIES),		\
	S(SNK_TRANSITION_SINK),			\
	S(SNK_TRANSITION_SINK_VBUS),		\
	S(SNK_READY),				\
						\
	S(ACC_UNATTACHED),			\
	S(DEBUG_ACC_ATTACHED),			\
	S(AUDIO_ACC_ATTACHED),			\
	S(AUDIO_ACC_DEBOUNCE),			\
						\
	S(HARD_RESET_SEND),			\
	S(HARD_RESET_START),			\
	S(SRC_HARD_RESET_VBUS_OFF),		\
	S(SRC_HARD_RESET_VBUS_ON),		\
	S(SNK_HARD_RESET_SINK_OFF),		\
	S(SNK_HARD_RESET_WAIT_VBUS),		\
	S(SNK_HARD_RESET_SINK_ON),		\
						\
	S(SOFT_RESET),				\
	S(SOFT_RESET_SEND),			\
						\
	S(DR_SWAP_ACCEPT),			\
	S(DR_SWAP_SEND),			\
	S(DR_SWAP_SEND_TIMEOUT),		\
	S(DR_SWAP_CANCEL),			\
	S(DR_SWAP_CHANGE_DR),			\
						\
	S(PR_SWAP_ACCEPT),			\
	S(PR_SWAP_SEND),			\
	S(PR_SWAP_SEND_TIMEOUT),		\
	S(PR_SWAP_CANCEL),			\
	S(PR_SWAP_START),			\
	S(PR_SWAP_SRC_SNK_TRANSITION_OFF),	\
	S(PR_SWAP_SRC_SNK_SOURCE_OFF),		\
	S(PR_SWAP_SRC_SNK_SINK_ON),		\
	S(PR_SWAP_SNK_SRC_SINK_OFF),		\
	S(PR_SWAP_SNK_SRC_SOURCE_ON),		\
						\
	S(VCONN_SWAP_ACCEPT),			\
	S(VCONN_SWAP_SEND),			\
	S(VCONN_SWAP_SEND_TIMEOUT),		\
	S(VCONN_SWAP_CANCEL),			\
	S(VCONN_SWAP_START),			\
	S(VCONN_SWAP_WAIT_FOR_VCONN),		\
	S(VCONN_SWAP_TURN_ON_VCONN),		\
	S(VCONN_SWAP_TURN_OFF_VCONN),		\
						\
	S(SNK_TRY),				\
	S(SNK_TRY_WAIT),			\
	S(SNK_TRY_WAIT_DEBOUNCE),		\
	S(SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS),	\
	S(SRC_TRYWAIT),				\
	S(SRC_TRYWAIT_DEBOUNCE),			\
	S(SRC_TRYWAIT_UNATTACHED),		\
						\
	S(SRC_TRY),				\
	S(SRC_TRY_DEBOUNCE),			\
	S(SNK_TRYWAIT),				\
	S(SNK_TRYWAIT_DEBOUNCE),		\
	S(SNK_TRYWAIT_VBUS),			\
	S(BIST_RX),				\
						\
	S(ERROR_RECOVERY),			\
	S(PORT_RESET),				\
	S(PORT_RESET_WAIT_OFF)

#define GENERATE_ENUM(e)	e
#define GENERATE_STRING(s)	#s

enum tcpm_state {
	FOREACH_STATE(GENERATE_ENUM)
};

static const char * const tcpm_states[] = {
	FOREACH_STATE(GENERATE_STRING)
};

enum vdm_states {
	VDM_STATE_ERR_BUSY = -3,
	VDM_STATE_ERR_SEND = -2,
	VDM_STATE_ERR_TMOUT = -1,
	VDM_STATE_DONE = 0,
	/* Anything >0 represents an active state */
	VDM_STATE_READY = 1,
	VDM_STATE_BUSY = 2,
	VDM_STATE_WAIT_RSP_BUSY = 3,
};

enum pd_msg_request {
	PD_MSG_NONE = 0,
	PD_MSG_CTRL_REJECT,
	PD_MSG_CTRL_WAIT,
	PD_MSG_DATA_SINK_CAP,
	PD_MSG_DATA_SOURCE_CAP,
};

/* Events from low level driver */

#define TCPM_CC_EVENT		BIT(0)
#define TCPM_VBUS_EVENT		BIT(1)
#define TCPM_RESET_EVENT	BIT(2)

#define LOG_BUFFER_ENTRIES	1024
#define LOG_BUFFER_ENTRY_SIZE	128

/* Alternate mode support */

#define SVID_DISCOVERY_MAX	16

struct pd_mode_data {
	int svid_index;		/* current SVID index		*/
	int nsvids;
	u16 svids[SVID_DISCOVERY_MAX];
	int altmodes;		/* number of alternate modes	*/
	struct typec_altmode_desc altmode_desc[SVID_DISCOVERY_MAX];
};

struct tcpm_port {
	struct device *dev;

	struct mutex lock;		/* tcpm state machine lock */
	struct workqueue_struct *wq;

	struct typec_capability typec_caps;
	struct typec_port *typec_port;

	struct tcpc_dev	*tcpc;

	enum typec_role vconn_role;
	enum typec_role pwr_role;
	enum typec_data_role data_role;
	enum typec_pwr_opmode pwr_opmode;

	struct usb_pd_identity partner_ident;
	struct typec_partner_desc partner_desc;
	struct typec_partner *partner;

	enum typec_cc_status cc_req;

	enum typec_cc_status cc1;
	enum typec_cc_status cc2;
	enum typec_cc_polarity polarity;

	bool attached;
	bool connected;
	enum typec_port_type port_type;
	bool vbus_present;
	bool vbus_never_low;
	bool vbus_source;
	bool vbus_charge;

	bool send_discover;
	bool op_vsafe5v;

	int try_role;
	int try_snk_count;
	int try_src_count;

	enum pd_msg_request queued_message;

	enum tcpm_state enter_state;
	enum tcpm_state prev_state;
	enum tcpm_state state;
	enum tcpm_state delayed_state;
	unsigned long delayed_runtime;
	unsigned long delay_ms;

	spinlock_t pd_event_lock;
	u32 pd_events;

	struct work_struct event_work;
	struct delayed_work state_machine;
	struct delayed_work vdm_state_machine;
	bool state_machine_running;

	struct completion tx_complete;
	enum tcpm_transmit_status tx_status;

	struct mutex swap_lock;		/* swap command lock */
	bool swap_pending;
	bool non_pd_role_swap;
	struct completion swap_complete;
	int swap_status;

	unsigned int message_id;
	unsigned int caps_count;
	unsigned int hard_reset_count;
	bool pd_capable;
	bool explicit_contract;
	unsigned int rx_msgid;

	/* Partner capabilities/requests */
	u32 sink_request;
	u32 source_caps[PDO_MAX_OBJECTS];
	unsigned int nr_source_caps;
	u32 sink_caps[PDO_MAX_OBJECTS];
	unsigned int nr_sink_caps;

	/* Local capabilities */
	u32 src_pdo[PDO_MAX_OBJECTS];
	unsigned int nr_src_pdo;
	u32 snk_pdo[PDO_MAX_OBJECTS];
	unsigned int nr_snk_pdo;
	u32 snk_vdo[VDO_MAX_OBJECTS];
	unsigned int nr_snk_vdo;

	unsigned int max_snk_mv;
	unsigned int max_snk_ma;
	unsigned int max_snk_mw;
	unsigned int operating_snk_mw;

	/* Requested current / voltage */
	u32 current_limit;
	u32 supply_voltage;

	u32 bist_request;

	/* PD state for Vendor Defined Messages */
	enum vdm_states vdm_state;
	u32 vdm_retries;
	/* next Vendor Defined Message to send */
	u32 vdo_data[VDO_MAX_SIZE];
	u8 vdo_count;
	/* VDO to retry if UFP responder replied busy */
	u32 vdo_retry;

	/* Alternate mode data */

	struct pd_mode_data mode_data;
	struct typec_altmode *partner_altmode[SVID_DISCOVERY_MAX];
	struct typec_altmode *port_altmode[SVID_DISCOVERY_MAX];

	/* Deadline in jiffies to exit src_try_wait state */
	unsigned long max_wait;

#ifdef CONFIG_DEBUG_FS
	struct dentry *dentry;
	struct mutex logbuffer_lock;	/* log buffer access lock */
	int logbuffer_head;
	int logbuffer_tail;
	u8 *logbuffer[LOG_BUFFER_ENTRIES];
#endif
};

struct pd_rx_event {
	struct work_struct work;
	struct tcpm_port *port;
	struct pd_message msg;
};

#define tcpm_cc_is_sink(cc) \
	((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
	 (cc) == TYPEC_CC_RP_3_0)

#define tcpm_port_is_sink(port) \
	((tcpm_cc_is_sink((port)->cc1) && !tcpm_cc_is_sink((port)->cc2)) || \
	 (tcpm_cc_is_sink((port)->cc2) && !tcpm_cc_is_sink((port)->cc1)))

#define tcpm_cc_is_source(cc) ((cc) == TYPEC_CC_RD)
#define tcpm_cc_is_audio(cc) ((cc) == TYPEC_CC_RA)
#define tcpm_cc_is_open(cc) ((cc) == TYPEC_CC_OPEN)

#define tcpm_port_is_source(port) \
	((tcpm_cc_is_source((port)->cc1) && \
	 !tcpm_cc_is_source((port)->cc2)) || \
	 (tcpm_cc_is_source((port)->cc2) && \
	  !tcpm_cc_is_source((port)->cc1)))

#define tcpm_port_is_debug(port) \
	(tcpm_cc_is_source((port)->cc1) && tcpm_cc_is_source((port)->cc2))

#define tcpm_port_is_audio(port) \
	(tcpm_cc_is_audio((port)->cc1) && tcpm_cc_is_audio((port)->cc2))

#define tcpm_port_is_audio_detached(port) \
	((tcpm_cc_is_audio((port)->cc1) && tcpm_cc_is_open((port)->cc2)) || \
	 (tcpm_cc_is_audio((port)->cc2) && tcpm_cc_is_open((port)->cc1)))

#define tcpm_try_snk(port) \
	((port)->try_snk_count == 0 && (port)->try_role == TYPEC_SINK && \
	(port)->port_type == TYPEC_PORT_DRP)

#define tcpm_try_src(port) \
	((port)->try_src_count == 0 && (port)->try_role == TYPEC_SOURCE && \
	port->port_type == TYPEC_PORT_DRP)

static enum tcpm_state tcpm_default_state(struct tcpm_port *port)
{
	if (port->port_type == TYPEC_PORT_DRP) {
		if (port->try_role == TYPEC_SINK)
			return SNK_UNATTACHED;
		else if (port->try_role == TYPEC_SOURCE)
			return SRC_UNATTACHED;
		else if (port->tcpc->config->default_role == TYPEC_SINK)
			return SNK_UNATTACHED;
		/* Fall through to return SRC_UNATTACHED */
	} else if (port->port_type == TYPEC_PORT_UFP) {
		return SNK_UNATTACHED;
	}
	return SRC_UNATTACHED;
}

extern bool IsPRSwap;

static inline
struct tcpm_port *typec_cap_to_tcpm(const struct typec_capability *cap)
{
	return container_of(cap, struct tcpm_port, typec_caps);
}

static bool tcpm_port_is_disconnected(struct tcpm_port *port)
{
	return (!port->attached && port->cc1 == TYPEC_CC_OPEN &&
		port->cc2 == TYPEC_CC_OPEN) ||
	       (port->attached && ((port->polarity == TYPEC_POLARITY_CC1 &&
				    port->cc1 == TYPEC_CC_OPEN) ||
				   (port->polarity == TYPEC_POLARITY_CC2 &&
				    port->cc2 == TYPEC_CC_OPEN)));
}

/*
 * Logging
 */

#ifdef CONFIG_DEBUG_FS

static void _tcpm_log(struct tcpm_port *port, const char *fmt, va_list args)
{
	char tmpbuffer[LOG_BUFFER_ENTRY_SIZE];
	u64 ts_nsec = local_clock();
	unsigned long rem_nsec;

	if (!port->logbuffer[port->logbuffer_head]) {
		port->logbuffer[port->logbuffer_head] =
				kzalloc(LOG_BUFFER_ENTRY_SIZE, GFP_KERNEL);
		if (!port->logbuffer[port->logbuffer_head])
			return;
	}

	vsnprintf(tmpbuffer, sizeof(tmpbuffer), fmt, args);

	mutex_lock(&port->logbuffer_lock);

	if (port->logbuffer_head < 0 ||
	    port->logbuffer_head >= LOG_BUFFER_ENTRIES) {
		dev_warn(port->dev,
			 "Bad log buffer index %d\n", port->logbuffer_head);
		goto abort;
	}

	if (!port->logbuffer[port->logbuffer_head]) {
		dev_warn(port->dev,
			 "Log buffer index %d is NULL\n", port->logbuffer_head);
		goto abort;
	}

	rem_nsec = do_div(ts_nsec, 1000000000);
	scnprintf(port->logbuffer[port->logbuffer_head],
		  LOG_BUFFER_ENTRY_SIZE, "[%5lu.%06lu] %s",
		  (unsigned long)ts_nsec, rem_nsec / 1000,
		  tmpbuffer);
	port->logbuffer_head = (port->logbuffer_head + 1) % LOG_BUFFER_ENTRIES;
	if (port->logbuffer_head == port->logbuffer_tail)
		port->logbuffer_tail =
				(port->logbuffer_tail + 1) % LOG_BUFFER_ENTRIES;

abort:
	mutex_unlock(&port->logbuffer_lock);
}

static void tcpm_log(struct tcpm_port *port, const char *fmt, ...)
{
	va_list args;

	/* Do not log while disconnected and unattached */
	if (tcpm_port_is_disconnected(port) &&
	    (port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED ||
	     port->state == DRP_TOGGLING))
		return;

	va_start(args, fmt);
	_tcpm_log(port, fmt, args);
	va_end(args);
}

static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	_tcpm_log(port, fmt, args);
	va_end(args);
}

static void tcpm_log_source_caps(struct tcpm_port *port)
{
	int i;

	for (i = 0; i < port->nr_source_caps; i++) {
		u32 pdo = port->source_caps[i];
		enum pd_pdo_type type = pdo_type(pdo);
		char msg[64];

		switch (type) {
		case PDO_TYPE_FIXED:
			scnprintf(msg, sizeof(msg),
				  "%u mV, %u mA [%s%s%s%s%s%s]",
				  pdo_fixed_voltage(pdo),
				  pdo_max_current(pdo),
				  (pdo & PDO_FIXED_DUAL_ROLE) ?
							"R" : "",
				  (pdo & PDO_FIXED_SUSPEND) ?
							"S" : "",
				  (pdo & PDO_FIXED_HIGHER_CAP) ?
							"H" : "",
				  (pdo & PDO_FIXED_USB_COMM) ?
							"U" : "",
				  (pdo & PDO_FIXED_DATA_SWAP) ?
							"D" : "",
				  (pdo & PDO_FIXED_EXTPOWER) ?
							"E" : "");
			break;
		case PDO_TYPE_VAR:
			scnprintf(msg, sizeof(msg),
				  "%u-%u mV, %u mA",
				  pdo_min_voltage(pdo),
				  pdo_max_voltage(pdo),
				  pdo_max_current(pdo));
			break;
		case PDO_TYPE_BATT:
			scnprintf(msg, sizeof(msg),
				  "%u-%u mV, %u mW",
				  pdo_min_voltage(pdo),
				  pdo_max_voltage(pdo),
				  pdo_max_power(pdo));
			break;
		default:
			strlcpy(msg, "undefined", sizeof(msg));
			break;
		}
		tcpm_log(port, " PDO %d: type %d, %s",
			 i, type, msg);
	}
}

static int tcpm_seq_show(struct seq_file *s, void *v)
{
	struct tcpm_port *port = (struct tcpm_port *)s->private;
	int tail;

	mutex_lock(&port->logbuffer_lock);
	tail = port->logbuffer_tail;
	while (tail != port->logbuffer_head) {
		if (seq_printf(s, "%s\n", port->logbuffer[tail]) < 0)
			goto abort;
		tail = (tail + 1) % LOG_BUFFER_ENTRIES;
	}
	port->logbuffer_tail = tail;
abort:
	mutex_unlock(&port->logbuffer_lock);

	return 0;
}

static int tcpm_debug_open(struct inode *inode, struct file *file)
{
	return single_open(file, tcpm_seq_show, inode->i_private);
}

static const struct file_operations tcpm_debug_operations = {
	.open		= tcpm_debug_open,
	.llseek		= seq_lseek,
	.read		= seq_read,
	.release	= single_release,
};

static struct dentry *rootdir;

static int tcpm_debugfs_init(struct tcpm_port *port)
{
	mutex_init(&port->logbuffer_lock);
	/* /sys/kernel/debug/tcpm/usbcX */
	if (!rootdir) {
		rootdir = debugfs_create_dir("tcpm", NULL);
		if (!rootdir)
			return -ENOMEM;
	}

	port->dentry = debugfs_create_file(dev_name(port->dev),
					   S_IFREG | 0444, rootdir,
					   port, &tcpm_debug_operations);

	return 0;
}

static void tcpm_debugfs_exit(struct tcpm_port *port)
{
	debugfs_remove(port->dentry);
}

#else

static void tcpm_log(const struct tcpm_port *port, const char *fmt, ...) { }
static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...) { }
static void tcpm_log_source_caps(struct tcpm_port *port) { }
static int tcpm_debugfs_init(const struct tcpm_port *port) { return 0; }
static void tcpm_debugfs_exit(const struct tcpm_port *port) { }

#endif

static int tcpm_pd_transmit(struct tcpm_port *port,
			    enum tcpm_transmit_type type,
			    const struct pd_message *msg)
{
	unsigned long timeout;
	int ret;

	if (msg)
		tcpm_log(port, "PD TX, header: %#x", le16_to_cpu(msg->header));
	else
		tcpm_log(port, "PD TX, type: %#x", type);

	reinit_completion(&port->tx_complete);
	ret = port->tcpc->pd_transmit(port->tcpc, type, msg);
	if (ret < 0)
		return ret;

	mutex_unlock(&port->lock);
	timeout = wait_for_completion_timeout(&port->tx_complete,
				msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
	mutex_lock(&port->lock);
	if (!timeout)
		return -ETIMEDOUT;

	switch (port->tx_status) {
	case TCPC_TX_SUCCESS:
		port->message_id = (port->message_id + 1) & PD_HEADER_ID_MASK;
		return 0;
	case TCPC_TX_DISCARDED:
		return -EAGAIN;
	case TCPC_TX_FAILED:
	default:
		return -EIO;
	}
}

void tcpm_pd_transmit_complete(struct tcpm_port *port,
			       enum tcpm_transmit_status status)
{
	tcpm_log(port, "PD TX complete, status: %u", status);
	port->tx_status = status;
	complete(&port->tx_complete);
}
EXPORT_SYMBOL_GPL(tcpm_pd_transmit_complete);

static int tcpm_mux_set(struct tcpm_port *port, enum tcpc_mux_mode mode,
			enum tcpc_usb_switch config)
{
	int ret = 0;

	tcpm_log(port, "Requesting mux mode %d, config %d, polarity %d",
		 mode, config, port->polarity);

	if (port->tcpc->mux)
		ret = port->tcpc->mux->set(port->tcpc->mux, mode, config,
					   port->polarity);

	return ret;
}

static int tcpm_set_polarity(struct tcpm_port *port,
			     enum typec_cc_polarity polarity)
{
	int ret;

	tcpm_log(port, "polarity %d", polarity);

	ret = port->tcpc->set_polarity(port->tcpc, polarity);
	if (ret < 0)
		return ret;

	port->polarity = polarity;

	return 0;
}

static int tcpm_set_vconn(struct tcpm_port *port, bool enable)
{
	int ret;

	tcpm_log(port, "vconn:=%d", enable);

	ret = port->tcpc->set_vconn(port->tcpc, enable);
	if (!ret) {
		port->vconn_role = enable ? TYPEC_SOURCE : TYPEC_SINK;
		typec_set_vconn_role(port->typec_port, port->vconn_role);
	}

	return ret;
}

static u32 tcpm_get_current_limit(struct tcpm_port *port)
{
	enum typec_cc_status cc;
	u32 limit;

	cc = port->polarity ? port->cc2 : port->cc1;
	switch (cc) {
	case TYPEC_CC_RP_1_5:
		limit = 1500;
		break;
	case TYPEC_CC_RP_3_0:
		limit = 3000;
		break;
	case TYPEC_CC_RP_DEF:
	default:
		limit = 0;
		break;
	}

	return limit;
}

static int tcpm_set_current_limit(struct tcpm_port *port, u32 max_ma, u32 mv)
{
	int ret = -EOPNOTSUPP;

	tcpm_log(port, "Setting voltage/current limit %u mV %u mA", mv, max_ma);

	if (port->tcpc->set_current_limit)
		ret = port->tcpc->set_current_limit(port->tcpc, max_ma, mv);

	return ret;
}

/*
 * Determine RP value to set based on maximum current supported
 * by a port if configured as source.
 * Returns CC value to report to link partner.
 */
static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
{
	const u32 *src_pdo = port->src_pdo;
	int nr_pdo = port->nr_src_pdo;
	int i;

	/*
	 * Search for first entry with matching voltage.
	 * It should report the maximum supported current.
	 */
	for (i = 0; i < nr_pdo; i++) {
		const u32 pdo = src_pdo[i];

		if (pdo_type(pdo) == PDO_TYPE_FIXED &&
		    pdo_fixed_voltage(pdo) == 5000) {
			unsigned int curr = pdo_max_current(pdo);

			if (curr >= 3000)
				return TYPEC_CC_RP_3_0;
			else if (curr >= 1500)
				return TYPEC_CC_RP_1_5;
			return TYPEC_CC_RP_DEF;
		}
	}

	return TYPEC_CC_RP_DEF;
}

static int tcpm_set_attached_state(struct tcpm_port *port, bool attached)
{
	return port->tcpc->set_roles(port->tcpc, attached, port->pwr_role,
				     port->data_role);
}

static int tcpm_set_roles(struct tcpm_port *port, bool attached,
			  enum typec_role role, enum typec_data_role data)
{
	int ret;

	if (data == TYPEC_HOST)
		ret = tcpm_mux_set(port, TYPEC_MUX_USB,
				   TCPC_USB_SWITCH_CONNECT);
	else
		ret = tcpm_mux_set(port, TYPEC_MUX_NONE,
				   TCPC_USB_SWITCH_DISCONNECT);
	if (ret < 0)
		return ret;

	ret = port->tcpc->set_roles(port->tcpc, attached, role, data);
	if (ret < 0)
		return ret;

	port->pwr_role = role;
	port->data_role = data;
	typec_set_data_role(port->typec_port, data);
	typec_set_pwr_role(port->typec_port, role);

	return 0;
}

static int tcpm_set_pwr_role(struct tcpm_port *port, enum typec_role role)
{
	int ret;

	ret = port->tcpc->set_roles(port->tcpc, true, role,
				    port->data_role);
	if (ret < 0)
		return ret;

	port->pwr_role = role;
	typec_set_pwr_role(port->typec_port, role);

	return 0;
}

static int tcpm_pd_send_source_caps(struct tcpm_port *port)
{
	struct pd_message msg;
	int i;

	memset(&msg, 0, sizeof(msg));
	if (!port->nr_src_pdo) {
		/* No source capabilities defined, sink only */
		msg.header = PD_HEADER_LE(PD_CTRL_REJECT,
					  port->pwr_role,
					  port->data_role,
					  port->message_id, 0);
	} else {
		msg.header = PD_HEADER_LE(PD_DATA_SOURCE_CAP,
					  port->pwr_role,
					  port->data_role,
					  port->message_id,
					  port->nr_src_pdo);
	}
	for (i = 0; i < port->nr_src_pdo; i++)
		msg.payload[i] = cpu_to_le32(port->src_pdo[i]);

	return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

static int tcpm_pd_send_sink_caps(struct tcpm_port *port)
{
	struct pd_message msg;
	int i;

	memset(&msg, 0, sizeof(msg));
	if (!port->nr_snk_pdo) {
		/* No sink capabilities defined, source only */
		msg.header = PD_HEADER_LE(PD_CTRL_REJECT,
					  port->pwr_role,
					  port->data_role,
					  port->message_id, 0);
	} else {
		msg.header = PD_HEADER_LE(PD_DATA_SINK_CAP,
					  port->pwr_role,
					  port->data_role,
					  port->message_id,
					  port->nr_snk_pdo);
	}
	for (i = 0; i < port->nr_snk_pdo; i++)
		msg.payload[i] = cpu_to_le32(port->snk_pdo[i]);

	return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

static void tcpm_set_state(struct tcpm_port *port, enum tcpm_state state,
			   unsigned int delay_ms)
{
	if (delay_ms) {
		tcpm_log(port, "pending state change %s -> %s @ %u ms",
			 tcpm_states[port->state], tcpm_states[state],
			 delay_ms);
		port->delayed_state = state;
		mod_delayed_work(port->wq, &port->state_machine,
				 msecs_to_jiffies(delay_ms));
		port->delayed_runtime = jiffies + msecs_to_jiffies(delay_ms);
		port->delay_ms = delay_ms;
	} else {
		tcpm_log(port, "state change %s -> %s",
			 tcpm_states[port->state], tcpm_states[state]);
		port->delayed_state = INVALID_STATE;
		port->prev_state = port->state;
		port->state = state;
		/*
		 * Don't re-queue the state machine work item if we're currently
		 * in the state machine and we're immediately changing states.
		 * tcpm_state_machine_work() will continue running the state
		 * machine.
		 */
		if (!port->state_machine_running)
			mod_delayed_work(port->wq, &port->state_machine, 0);
	}
}

static void tcpm_set_state_cond(struct tcpm_port *port, enum tcpm_state state,
				unsigned int delay_ms)
{
	if (port->enter_state == port->state)
		tcpm_set_state(port, state, delay_ms);
	else
		tcpm_log(port,
			 "skipped %sstate change %s -> %s [%u ms], context state %s",
			 delay_ms ? "delayed " : "",
			 tcpm_states[port->state], tcpm_states[state],
			 delay_ms, tcpm_states[port->enter_state]);
}

static void tcpm_queue_message(struct tcpm_port *port,
			       enum pd_msg_request message)
{
	port->queued_message = message;
	mod_delayed_work(port->wq, &port->state_machine, 0);
}

/*
 * VDM/VDO handling functions
 */
static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header,
			   const u32 *data, int cnt)
{
	port->vdo_count = cnt + 1;
	port->vdo_data[0] = header;
	memcpy(&port->vdo_data[1], data, sizeof(u32) * cnt);
	/* Set ready, vdm state machine will actually send */
	port->vdm_retries = 0;
	port->vdm_state = VDM_STATE_READY;
}

static void svdm_consume_identity(struct tcpm_port *port, const __le32 *payload,
				  int cnt)
{
	u32 vdo = le32_to_cpu(payload[VDO_INDEX_IDH]);
	u32 product = le32_to_cpu(payload[VDO_INDEX_PRODUCT]);

	memset(&port->mode_data, 0, sizeof(port->mode_data));

#if 0 /* Not really a match */
	switch (PD_IDH_PTYPE(vdo)) {
	case IDH_PTYPE_UNDEF:
		port->partner.type = TYPEC_PARTNER_NONE; /* no longer exists */
		break;
	case IDH_PTYPE_HUB:
		break;
	case IDH_PTYPE_PERIPH:
		break;
	case IDH_PTYPE_PCABLE:
		break;
	case IDH_PTYPE_ACABLE:
		break;
	case IDH_PTYPE_AMA:
		port->partner.type = TYPEC_PARTNER_ALTMODE;
		break;
	default:
		break;
	}
#endif

	port->partner_ident.id_header = vdo;
	port->partner_ident.cert_stat = le32_to_cpu(payload[VDO_INDEX_CSTAT]);
	port->partner_ident.product = product;

	typec_partner_set_identity(port->partner);

	tcpm_log(port, "Identity: %04x:%04x.%04x",
		 PD_IDH_VID(vdo),
		 PD_PRODUCT_PID(product), product & 0xffff);
}

static bool svdm_consume_svids(struct tcpm_port *port, const __le32 *payload,
			       int cnt)
{
	struct pd_mode_data *pmdata = &port->mode_data;
	int i;

	for (i = 1; i < cnt; i++) {
		u32 p = le32_to_cpu(payload[i]);
		u16 svid;

		svid = (p >> 16) & 0xffff;
		if (!svid)
			return false;

		if (pmdata->nsvids >= SVID_DISCOVERY_MAX)
			goto abort;

		pmdata->svids[pmdata->nsvids++] = svid;
		tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid);

		svid = p & 0xffff;
		if (!svid)
			return false;

		if (pmdata->nsvids >= SVID_DISCOVERY_MAX)
			goto abort;

		pmdata->svids[pmdata->nsvids++] = svid;
		tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid);
	}
	return true;
abort:
	tcpm_log(port, "SVID_DISCOVERY_MAX(%d) too low!", SVID_DISCOVERY_MAX);
	return false;
}

static void svdm_consume_modes(struct tcpm_port *port, const __le32 *payload,
			       int cnt)
{
	struct pd_mode_data *pmdata = &port->mode_data;
	struct typec_altmode_desc *paltmode;
	struct typec_mode_desc *pmode;
	int i;

	if (pmdata->altmodes >= ARRAY_SIZE(port->partner_altmode)) {
		/* Already logged in svdm_consume_svids() */
		return;
	}

	paltmode = &pmdata->altmode_desc[pmdata->altmodes];
	memset(paltmode, 0, sizeof(*paltmode));

	paltmode->svid = pmdata->svids[pmdata->svid_index];

	tcpm_log(port, " Alternate mode %d: SVID 0x%04x",
		 pmdata->altmodes, paltmode->svid);

	for (i = 1; i < cnt && paltmode->n_modes < ALTMODE_MAX_MODES; i++) {
		pmode = &paltmode->modes[paltmode->n_modes];
		memset(pmode, 0, sizeof(*pmode));
		pmode->vdo = le32_to_cpu(payload[i]);
		pmode->index = i - 1;
		paltmode->n_modes++;
		tcpm_log(port, "  VDO %d: 0x%08x",
			 pmode->index, pmode->vdo);
	}
	port->partner_altmode[pmdata->altmodes] =
		typec_partner_register_altmode(port->partner, paltmode);
	if (port->partner_altmode[pmdata->altmodes] == NULL) {
		tcpm_log(port,
			 "Failed to register alternate modes for SVID 0x%04x",
			 paltmode->svid);
		return;
	}
	pmdata->altmodes++;
}

#define supports_modal(port)	PD_IDH_MODAL_SUPP((port)->partner_ident.id_header)

static int tcpm_pd_svdm(struct tcpm_port *port, const __le32 *payload, int cnt,
			u32 *response)
{
	u32 p0 = le32_to_cpu(payload[0]);
	int cmd_type = PD_VDO_CMDT(p0);
	int cmd = PD_VDO_CMD(p0);
	struct pd_mode_data *modep;
	int rlen = 0;
	u16 svid;
	int i;

	tcpm_log(port, "Rx VDM cmd 0x%x type %d cmd %d len %d",
		 p0, cmd_type, cmd, cnt);

	modep = &port->mode_data;

	switch (cmd_type) {
	case CMDT_INIT:
		switch (cmd) {
		case CMD_DISCOVER_IDENT:
			/* 6.4.4.3.1: Only respond as UFP (device) */
			if (port->data_role == TYPEC_DEVICE &&
			    port->nr_snk_vdo) {
				for (i = 0; i <  port->nr_snk_vdo; i++)
					response[i + 1]
						= cpu_to_le32(port->snk_vdo[i]);
				rlen = port->nr_snk_vdo + 1;
			}
			break;
		case CMD_DISCOVER_SVID:
			break;
		case CMD_DISCOVER_MODES:
			break;
		case CMD_ENTER_MODE:
			break;
		case CMD_EXIT_MODE:
			break;
		case CMD_ATTENTION:
			break;
		default:
			break;
		}
		if (rlen >= 1) {
			response[0] = p0 | VDO_CMDT(CMDT_RSP_ACK);
		} else if (rlen == 0) {
			response[0] = p0 | VDO_CMDT(CMDT_RSP_NAK);
			rlen = 1;
		} else {
			response[0] = p0 | VDO_CMDT(CMDT_RSP_BUSY);
			rlen = 1;
		}
		break;
	case CMDT_RSP_ACK:
		/* silently drop message if we are not connected */
		if (!port->partner) {
			tcpm_log(port,
				 "port partner is NULL, ignore stray CMDT_RSP_ACK");
			break;
		}
		switch (cmd) {
		case CMD_DISCOVER_IDENT:
			/* 6.4.4.3.1 */
			svdm_consume_identity(port, payload, cnt);
			response[0] = VDO(USB_SID_PD, 1, CMD_DISCOVER_SVID);
			rlen = 1;
			break;
		case CMD_DISCOVER_SVID:
			/* 6.4.4.3.2 */
			if (svdm_consume_svids(port, payload, cnt)) {
				response[0] = VDO(USB_SID_PD, 1,
						  CMD_DISCOVER_SVID);
				rlen = 1;
			} else if (modep->nsvids && supports_modal(port)) {
				response[0] = VDO(modep->svids[0], 1,
						  CMD_DISCOVER_MODES);
				rlen = 1;
			}
			break;
		case CMD_DISCOVER_MODES:
			/* 6.4.4.3.3 */
			svdm_consume_modes(port, payload, cnt);
			modep->svid_index++;
			if (modep->svid_index < modep->nsvids) {
				svid = modep->svids[modep->svid_index];
				response[0] = VDO(svid, 1, CMD_DISCOVER_MODES);
				rlen = 1;
			} else {
#if 0
				response[0] = pd_dfp_enter_mode(port, 0, 0);
				if (response[0])
					rlen = 1;
#endif
			}
			break;
		case CMD_ENTER_MODE:
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return rlen;
}

static void tcpm_handle_vdm_request(struct tcpm_port *port,
				    const __le32 *payload, int cnt)
{
	int rlen = 0;
	u32 response[8] = { };
	u32 p0 = le32_to_cpu(payload[0]);

	if (port->vdm_state == VDM_STATE_BUSY) {
		/* If UFP responded busy retry after timeout */
		if (PD_VDO_CMDT(p0) == CMDT_RSP_BUSY) {
			port->vdm_state = VDM_STATE_WAIT_RSP_BUSY;
			port->vdo_retry = (p0 & ~VDO_CMDT_MASK) |
				CMDT_INIT;
			mod_delayed_work(port->wq, &port->vdm_state_machine,
					 msecs_to_jiffies(PD_T_VDM_BUSY));
			return;
		}
		port->vdm_state = VDM_STATE_DONE;
	}

	if (PD_VDO_SVDM(p0))
		rlen = tcpm_pd_svdm(port, payload, cnt, response);
#if 0
	else
		rlen = tcpm_pd_custom_vdm(port, cnt, payload, response);
#endif

	if (rlen > 0) {
		tcpm_queue_vdm(port, response[0], &response[1], rlen - 1);
		mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
	}
}

static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd,
			  const u32 *data, int count)
{
	u32 header;

	if (WARN_ON(count > VDO_MAX_SIZE - 1))
		count = VDO_MAX_SIZE - 1;

	/* set VDM header with VID & CMD */
	header = VDO(vid, ((vid & USB_SID_PD) == USB_SID_PD) ?
			1 : (PD_VDO_CMD(cmd) <= CMD_ATTENTION), cmd);
	tcpm_queue_vdm(port, header, data, count);

	mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
}

static unsigned int vdm_ready_timeout(u32 vdm_hdr)
{
	unsigned int timeout;
	int cmd = PD_VDO_CMD(vdm_hdr);

	/* its not a structured VDM command */
	if (!PD_VDO_SVDM(vdm_hdr))
		return PD_T_VDM_UNSTRUCTURED;

	switch (PD_VDO_CMDT(vdm_hdr)) {
	case CMDT_INIT:
		if (cmd == CMD_ENTER_MODE || cmd == CMD_EXIT_MODE)
			timeout = PD_T_VDM_WAIT_MODE_E;
		else
			timeout = PD_T_VDM_SNDR_RSP;
		break;
	default:
		if (cmd == CMD_ENTER_MODE || cmd == CMD_EXIT_MODE)
			timeout = PD_T_VDM_E_MODE;
		else
			timeout = PD_T_VDM_RCVR_RSP;
		break;
	}
	return timeout;
}

static void vdm_run_state_machine(struct tcpm_port *port)
{
	struct pd_message msg;
	int i, res;

	switch (port->vdm_state) {
	case VDM_STATE_READY:
		/* Only transmit VDM if attached */
		if (!port->attached) {
			port->vdm_state = VDM_STATE_ERR_BUSY;
			break;
		}

		/*
		 * if there's traffic or we're not in PDO ready state don't send
		 * a VDM.
		 */
		if (port->state != SRC_READY && port->state != SNK_READY)
			break;

		/* Prepare and send VDM */
		memset(&msg, 0, sizeof(msg));
		msg.header = PD_HEADER_LE(PD_DATA_VENDOR_DEF,
					  port->pwr_role,
					  port->data_role,
					  port->message_id, port->vdo_count);
		for (i = 0; i < port->vdo_count; i++)
			msg.payload[i] = cpu_to_le32(port->vdo_data[i]);
		res = tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
		if (res < 0) {
			port->vdm_state = VDM_STATE_ERR_SEND;
		} else {
			unsigned long timeout;

			port->vdm_retries = 0;
			port->vdm_state = VDM_STATE_BUSY;
			timeout = vdm_ready_timeout(port->vdo_data[0]);
			mod_delayed_work(port->wq, &port->vdm_state_machine,
					 timeout);
		}
		break;
	case VDM_STATE_WAIT_RSP_BUSY:
		port->vdo_data[0] = port->vdo_retry;
		port->vdo_count = 1;
		port->vdm_state = VDM_STATE_READY;
		break;
	case VDM_STATE_BUSY:
		port->vdm_state = VDM_STATE_ERR_TMOUT;
		break;
	case VDM_STATE_ERR_SEND:
		/*
		 * A partner which does not support USB PD will not reply,
		 * so this is not a fatal error. At the same time, some
		 * devices may not return GoodCRC under some circumstances,
		 * so we need to retry.
		 */
		if (port->vdm_retries < 3) {
			tcpm_log(port, "VDM Tx error, retry");
			port->vdm_retries++;
			port->vdm_state = VDM_STATE_READY;
		}
		break;
	default:
		break;
	}
}

static void vdm_state_machine_work(struct work_struct *work)
{
	struct tcpm_port *port = container_of(work, struct tcpm_port,
					      vdm_state_machine.work);
	enum vdm_states prev_state;

	mutex_lock(&port->lock);

	/*
	 * Continue running as long as the port is not busy and there was
	 * a state change.
	 */
	do {
		prev_state = port->vdm_state;
		vdm_run_state_machine(port);
	} while (port->vdm_state != prev_state &&
		 port->vdm_state != VDM_STATE_BUSY);

	mutex_unlock(&port->lock);
}

/*
 * PD (data, control) command handling functions
 */
static void tcpm_pd_data_request(struct tcpm_port *port,
				 const struct pd_message *msg)
{
	enum pd_data_msg_type type = pd_header_type_le(msg->header);
	unsigned int cnt = pd_header_cnt_le(msg->header);
	unsigned int i;

	switch (type) {
	case PD_DATA_SOURCE_CAP:
		if (port->pwr_role != TYPEC_SINK)
			break;

		for (i = 0; i < cnt; i++)
			port->source_caps[i] = le32_to_cpu(msg->payload[i]);

		port->nr_source_caps = cnt;

		tcpm_log_source_caps(port);

		/*
		 * This message may be received even if VBUS is not
		 * present. This is quite unexpected; see USB PD
		 * specification, sections 8.3.3.6.3.1 and 8.3.3.6.3.2.
		 * However, at the same time, we must be ready to
		 * receive this message and respond to it 15ms after
		 * receiving PS_RDY during power swap operations, no matter
		 * if VBUS is available or not (USB PD specification,
		 * section 6.5.9.2).
		 * So we need to accept the message either way,
		 * but be prepared to keep waiting for VBUS after it was
		 * handled.
		 */
		tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
		break;
	case PD_DATA_REQUEST:
		if (port->pwr_role != TYPEC_SOURCE ||
		    cnt != 1) {
			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
			break;
		}
		port->sink_request = le32_to_cpu(msg->payload[0]);
		tcpm_set_state(port, SRC_NEGOTIATE_CAPABILITIES, 0);
		break;
	case PD_DATA_SINK_CAP:
		/* We don't do anything with this at the moment... */
		for (i = 0; i < cnt; i++)
			port->sink_caps[i] = le32_to_cpu(msg->payload[i]);
		port->nr_sink_caps = cnt;
		break;
	case PD_DATA_VENDOR_DEF:
		tcpm_handle_vdm_request(port, msg->payload, cnt);
		break;
	case PD_DATA_BIST:
		if (port->state == SRC_READY || port->state == SNK_READY) {
			port->bist_request = le32_to_cpu(msg->payload[0]);
			tcpm_set_state(port, BIST_RX, 0);
		}
		break;
	default:
		tcpm_log(port, "Unhandled data message type %#x", type);
		break;
	}
}

static void tcpm_pd_ctrl_request(struct tcpm_port *port,
				 const struct pd_message *msg)
{
	enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
	enum tcpm_state next_state;

	switch (type) {
	case PD_CTRL_GOOD_CRC:
	case PD_CTRL_PING:
		break;
	case PD_CTRL_GET_SOURCE_CAP:
		switch (port->state) {
		case SRC_READY:
		case SNK_READY:
			tcpm_queue_message(port, PD_MSG_DATA_SOURCE_CAP);
			break;
		default:
			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
			break;
		}
		break;
	case PD_CTRL_GET_SINK_CAP:
		switch (port->state) {
		case SRC_READY:
		case SNK_READY:
			tcpm_queue_message(port, PD_MSG_DATA_SINK_CAP);
			break;
		default:
			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
			break;
		}
		break;
	case PD_CTRL_GOTO_MIN:
		break;
	case PD_CTRL_PS_RDY:
		switch (port->state) {
		case SNK_TRANSITION_SINK:
			if (port->vbus_present) {
				tcpm_set_current_limit(port,
						       port->current_limit,
						       port->supply_voltage);
				tcpm_set_state(port, SNK_READY, 0);
			} else {
				/*
				 * Seen after power swap. Keep waiting for VBUS
				 * in a transitional state.
				 */
				tcpm_set_state(port,
					       SNK_TRANSITION_SINK_VBUS, 0);
			}
			break;
		case PR_SWAP_SRC_SNK_SOURCE_OFF:
			tcpm_set_state(port, PR_SWAP_SRC_SNK_SINK_ON, 0);
			break;
		case PR_SWAP_SNK_SRC_SINK_OFF:
			tcpm_set_state(port, PR_SWAP_SNK_SRC_SOURCE_ON, 0);
			break;
		case VCONN_SWAP_WAIT_FOR_VCONN:
			tcpm_set_state(port, VCONN_SWAP_TURN_OFF_VCONN, 0);
			break;
		default:
			break;
		}
		break;
	case PD_CTRL_REJECT:
	case PD_CTRL_WAIT:
		switch (port->state) {
		case SNK_NEGOTIATE_CAPABILITIES:
			/* USB PD specification, Figure 8-43 */
			if (port->explicit_contract)
				next_state = SNK_READY;
			else
				next_state = SNK_WAIT_CAPABILITIES;
			tcpm_set_state(port, next_state, 0);
			break;
		case DR_SWAP_SEND:
			port->swap_status = (type == PD_CTRL_WAIT ?
					     -EAGAIN : -EOPNOTSUPP);
			tcpm_set_state(port, DR_SWAP_CANCEL, 0);
			break;
		case PR_SWAP_SEND:
			port->swap_status = (type == PD_CTRL_WAIT ?
					     -EAGAIN : -EOPNOTSUPP);
			tcpm_set_state(port, PR_SWAP_CANCEL, 0);
			break;
		case VCONN_SWAP_SEND:
			port->swap_status = (type == PD_CTRL_WAIT ?
					     -EAGAIN : -EOPNOTSUPP);
			tcpm_set_state(port, VCONN_SWAP_CANCEL, 0);
			break;
		default:
			break;
		}
		break;
	case PD_CTRL_ACCEPT:
		switch (port->state) {
		case SNK_NEGOTIATE_CAPABILITIES:
			tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
			break;
		case SOFT_RESET_SEND:
			port->message_id = 0;
			port->rx_msgid = -1;
			if (port->pwr_role == TYPEC_SOURCE)
				next_state = SRC_SEND_CAPABILITIES;
			else
				next_state = SNK_WAIT_CAPABILITIES;
			tcpm_set_state(port, next_state, 0);
			break;
		case DR_SWAP_SEND:
			tcpm_set_state(port, DR_SWAP_CHANGE_DR, 0);
			break;
		case PR_SWAP_SEND:
			tcpm_set_state(port, PR_SWAP_START, 0);
			break;
		case VCONN_SWAP_SEND:
			tcpm_set_state(port, VCONN_SWAP_START, 0);
			break;
		default:
			break;
		}
		break;
	case PD_CTRL_SOFT_RESET:
		tcpm_set_state(port, SOFT_RESET, 0);
		break;
	case PD_CTRL_DR_SWAP:
		if (port->port_type != TYPEC_PORT_DRP) {
			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
			break;
		}
		/*
		 * XXX
		 * 6.3.9: If an alternate mode is active, a request to swap
		 * alternate modes shall trigger a port reset.
		 */
		switch (port->state) {
		case SRC_READY:
		case SNK_READY:
			tcpm_set_state(port, DR_SWAP_ACCEPT, 0);
			break;
		default:
			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
			break;
		}
		break;
	case PD_CTRL_PR_SWAP:
		if (port->port_type != TYPEC_PORT_DRP) {
			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
			break;
		}
		switch (port->state) {
		case SRC_READY:
		case SNK_READY:
			tcpm_set_state(port, PR_SWAP_ACCEPT, 0);
			break;
		default:
			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
			break;
		}
		break;
	case PD_CTRL_VCONN_SWAP:
		switch (port->state) {
		case SRC_READY:
		case SNK_READY:
			tcpm_set_state(port, VCONN_SWAP_ACCEPT, 0);
			break;
		default:
			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
			break;
		}
		break;
	default:
		tcpm_log(port, "Unhandled ctrl message type %#x", type);
		break;
	}
}

static void tcpm_pd_rx_handler(struct work_struct *work)
{
	struct pd_rx_event *event = container_of(work,
						 struct pd_rx_event, work);
	const struct pd_message *msg = &event->msg;
	unsigned int cnt = pd_header_cnt_le(msg->header);
	struct tcpm_port *port = event->port;

	mutex_lock(&port->lock);

	tcpm_log(port, "PD RX, header: %#x [%d]", le16_to_cpu(msg->header),
		 port->attached);

	if (port->attached) {
		enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
		unsigned int msgid = pd_header_msgid_le(msg->header);

		/*
		 * USB PD standard, 6.6.1.2:
		 * "... if MessageID value in a received Message is the
		 * same as the stored value, the receiver shall return a
		 * GoodCRC Message with that MessageID value and drop
		 * the Message (this is a retry of an already received
		 * Message). Note: this shall not apply to the Soft_Reset
		 * Message which always has a MessageID value of zero."
		 */
		if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET)
			goto done;
		port->rx_msgid = msgid;

		/*
		 * If both ends believe to be DFP/host, we have a data role
		 * mismatch.
		 */
		if (!!(le16_to_cpu(msg->header) & PD_HEADER_DATA_ROLE) ==
		    (port->data_role == TYPEC_HOST)) {
			tcpm_log(port,
				 "Data role mismatch, initiating error recovery");
			tcpm_set_state(port, ERROR_RECOVERY, 0);
		} else {
			if (cnt)
				tcpm_pd_data_request(port, msg);
			else
				tcpm_pd_ctrl_request(port, msg);
		}
	}

done:
	mutex_unlock(&port->lock);
	kfree(event);
}

void tcpm_pd_receive(struct tcpm_port *port, const struct pd_message *msg)
{
	struct pd_rx_event *event;

	event = kzalloc(sizeof(*event), GFP_ATOMIC);
	if (!event)
		return;

	INIT_WORK(&event->work, tcpm_pd_rx_handler);
	event->port = port;
	memcpy(&event->msg, msg, sizeof(*msg));
	queue_work(port->wq, &event->work);
}
EXPORT_SYMBOL_GPL(tcpm_pd_receive);

static int tcpm_pd_send_control(struct tcpm_port *port,
				enum pd_ctrl_msg_type type)
{
	struct pd_message msg;

	memset(&msg, 0, sizeof(msg));
	msg.header = PD_HEADER_LE(type, port->pwr_role,
				  port->data_role,
				  port->message_id, 0);

	return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

/*
 * Send queued message without affecting state.
 * Return true if state machine should go back to sleep,
 * false otherwise.
 */
static bool tcpm_send_queued_message(struct tcpm_port *port)
{
	enum pd_msg_request queued_message;

	do {
		queued_message = port->queued_message;
		port->queued_message = PD_MSG_NONE;

		switch (queued_message) {
		case PD_MSG_CTRL_WAIT:
			tcpm_pd_send_control(port, PD_CTRL_WAIT);
			break;
		case PD_MSG_CTRL_REJECT:
			tcpm_pd_send_control(port, PD_CTRL_REJECT);
			break;
		case PD_MSG_DATA_SINK_CAP:
			tcpm_pd_send_sink_caps(port);
			break;
		case PD_MSG_DATA_SOURCE_CAP:
			tcpm_pd_send_source_caps(port);
			break;
		default:
			break;
		}
	} while (port->queued_message != PD_MSG_NONE);

	if (port->delayed_state != INVALID_STATE) {
		if (time_is_after_jiffies(port->delayed_runtime)) {
			mod_delayed_work(port->wq, &port->state_machine,
					 port->delayed_runtime - jiffies);
			return true;
		}
		port->delayed_state = INVALID_STATE;
	}
	return false;
}

static int tcpm_pd_check_request(struct tcpm_port *port)
{
	u32 pdo, rdo = port->sink_request;
	unsigned int max, op, pdo_max, index;
	enum pd_pdo_type type;

	index = rdo_index(rdo);
	if (!index || index > port->nr_src_pdo)
		return -EINVAL;

	pdo = port->src_pdo[index - 1];
	type = pdo_type(pdo);
	switch (type) {
	case PDO_TYPE_FIXED:
	case PDO_TYPE_VAR:
		max = rdo_max_current(rdo);
		op = rdo_op_current(rdo);
		pdo_max = pdo_max_current(pdo);

		if (op > pdo_max)
			return -EINVAL;
		if (max > pdo_max && !(rdo & RDO_CAP_MISMATCH))
			return -EINVAL;

		if (type == PDO_TYPE_FIXED)
			tcpm_log(port,
				 "Requested %u mV, %u mA for %u / %u mA",
				 pdo_fixed_voltage(pdo), pdo_max, op, max);
		else
			tcpm_log(port,
				 "Requested %u -> %u mV, %u mA for %u / %u mA",
				 pdo_min_voltage(pdo), pdo_max_voltage(pdo),
				 pdo_max, op, max);
		break;
	case PDO_TYPE_BATT:
		max = rdo_max_power(rdo);
		op = rdo_op_power(rdo);
		pdo_max = pdo_max_power(pdo);

		if (op > pdo_max)
			return -EINVAL;
		if (max > pdo_max && !(rdo & RDO_CAP_MISMATCH))
			return -EINVAL;
		tcpm_log(port,
			 "Requested %u -> %u mV, %u mW for %u / %u mW",
			 pdo_min_voltage(pdo), pdo_max_voltage(pdo),
			 pdo_max, op, max);
		break;
	default:
		return -EINVAL;
	}

	port->op_vsafe5v = index == 1;

	return 0;
}

static int tcpm_pd_select_pdo(struct tcpm_port *port)
{
	unsigned int i, max_mw = 0, max_mv = 0;
	int ret = -EINVAL;

	/*
	 * Select the source PDO providing the most power while staying within
	 * the board's voltage limits. Prefer PDO providing exp
	 */
	for (i = 0; i < port->nr_source_caps; i++) {
		u32 pdo = port->source_caps[i];
		enum pd_pdo_type type = pdo_type(pdo);
		unsigned int mv, ma, mw;

		if (type == PDO_TYPE_FIXED)
			mv = pdo_fixed_voltage(pdo);
		else
			mv = pdo_min_voltage(pdo);

		if (type == PDO_TYPE_BATT) {
			mw = pdo_max_power(pdo);
		} else {
			ma = min(pdo_max_current(pdo),
				 port->max_snk_ma);
			mw = ma * mv / 1000;
		}

		/* Perfer higher voltages if available */
		if ((mw > max_mw || (mw == max_mw && mv > max_mv)) &&
		    mv <= port->max_snk_mv) {
			ret = i;
			max_mw = mw;
			max_mv = mv;
		}
	}

	return ret;
}

static int tcpm_pd_build_request(struct tcpm_port *port, u32 *rdo)
{
	unsigned int mv, ma, mw, flags;
	unsigned int max_ma, max_mw;
	enum pd_pdo_type type;
	int index;
	u32 pdo;

	index = tcpm_pd_select_pdo(port);
	if (index < 0)
		return -EINVAL;
	pdo = port->source_caps[index];
	type = pdo_type(pdo);

	if (type == PDO_TYPE_FIXED)
		mv = pdo_fixed_voltage(pdo);
	else
		mv = pdo_min_voltage(pdo);

	/* Select maximum available current within the board's power limit */
	if (type == PDO_TYPE_BATT) {
		mw = pdo_max_power(pdo);
		ma = 1000 * min(mw, port->max_snk_mw) / mv;
	} else {
		ma = min(pdo_max_current(pdo),
			 1000 * port->max_snk_mw / mv);
	}
	ma = min(ma, port->max_snk_ma);

	flags = RDO_USB_COMM | RDO_NO_SUSPEND;

	/* Set mismatch bit if offered power is less than operating power */
	mw = ma * mv / 1000;
	max_ma = ma;
	max_mw = mw;
	if (mw < port->operating_snk_mw) {
		flags |= RDO_CAP_MISMATCH;
		max_mw = port->operating_snk_mw;
		max_ma = max_mw * 1000 / mv;
	}

	tcpm_log(port, "cc=%d cc1=%d cc2=%d vbus=%d vconn=%s polarity=%d",
		 port->cc_req, port->cc1, port->cc2, port->vbus_source,
		 port->vconn_role == TYPEC_SOURCE ? "source" : "sink",
		 port->polarity);

	if (type == PDO_TYPE_BATT) {
		*rdo = RDO_BATT(index + 1, mw, max_mw, flags);

		tcpm_log(port, "Requesting PDO %d: %u mV, %u mW%s",
			 index, mv, mw,
			 flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
	} else {
		*rdo = RDO_FIXED(index + 1, ma, max_ma, flags);

		tcpm_log(port, "Requesting PDO %d: %u mV, %u mA%s",
			 index, mv, ma,
			 flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
	}

	port->current_limit = ma;
	port->supply_voltage = mv;

	return 0;
}

static int tcpm_pd_send_request(struct tcpm_port *port)
{
	struct pd_message msg;
	int ret;
	u32 rdo;

	ret = tcpm_pd_build_request(port, &rdo);
	if (ret < 0)
		return ret;

	memset(&msg, 0, sizeof(msg));
	msg.header = PD_HEADER_LE(PD_DATA_REQUEST,
				  port->pwr_role,
				  port->data_role,
				  port->message_id, 1);
	msg.payload[0] = cpu_to_le32(rdo);

	return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

static int tcpm_set_vbus(struct tcpm_port *port, bool enable)
{
	int ret;

	if (enable && port->vbus_charge)
		return -EINVAL;

	tcpm_log(port, "vbus:=%d charge=%d", enable, port->vbus_charge);

	ret = port->tcpc->set_vbus(port->tcpc, enable, port->vbus_charge);
	if (ret < 0)
		return ret;

	port->vbus_source = enable;
	return 0;
}

static int tcpm_set_charge(struct tcpm_port *port, bool charge)
{
	int ret;

	if (charge && port->vbus_source)
		return -EINVAL;

	if (charge != port->vbus_charge) {
		tcpm_log(port, "vbus=%d charge:=%d", port->vbus_source, charge);
		ret = port->tcpc->set_vbus(port->tcpc, port->vbus_source,
					   charge);
		if (ret < 0)
			return ret;
	}
	port->vbus_charge = charge;
	return 0;
}

static bool tcpm_start_drp_toggling(struct tcpm_port *port)
{
	int ret;

	if (port->tcpc->start_drp_toggling &&
	    port->port_type == TYPEC_PORT_DRP) {
		tcpm_log_force(port, "Start DRP toggling");
		ret = port->tcpc->start_drp_toggling(port->tcpc,
						     tcpm_rp_cc(port));
		if (!ret)
			return true;
	}

	return false;
}

static void tcpm_set_cc(struct tcpm_port *port, enum typec_cc_status cc)
{
	tcpm_log(port, "cc:=%d", cc);
	port->cc_req = cc;
	port->tcpc->set_cc(port->tcpc, cc);
}

static int tcpm_init_vbus(struct tcpm_port *port)
{
	int ret;

	ret = port->tcpc->set_vbus(port->tcpc, false, false);
	port->vbus_source = false;
	port->vbus_charge = false;
	return ret;
}

static int tcpm_init_vconn(struct tcpm_port *port)
{
	int ret;

	ret = port->tcpc->set_vconn(port->tcpc, false);
	port->vconn_role = TYPEC_SINK;
	return ret;
}

static void tcpm_typec_connect(struct tcpm_port *port)
{
	if (!port->connected) {
		/* Make sure we don't report stale identity information */
		memset(&port->partner_ident, 0, sizeof(port->partner_ident));
		port->partner_desc.usb_pd = port->pd_capable;
		if (tcpm_port_is_debug(port))
			port->partner_desc.accessory = TYPEC_ACCESSORY_DEBUG;
		else if (tcpm_port_is_audio(port))
			port->partner_desc.accessory = TYPEC_ACCESSORY_AUDIO;
		else
			port->partner_desc.accessory = TYPEC_ACCESSORY_NONE;
		port->partner = typec_register_partner(port->typec_port,
						       &port->partner_desc);
		port->connected = true;
	}
}

static int tcpm_src_attach(struct tcpm_port *port)
{
	enum typec_cc_polarity polarity =
				port->cc2 == TYPEC_CC_RD ? TYPEC_POLARITY_CC2
							 : TYPEC_POLARITY_CC1;
	int ret;

	if (port->attached)
		return 0;

	ret = tcpm_set_polarity(port, polarity);
	if (ret < 0)
		return ret;

	ret = tcpm_set_roles(port, true, TYPEC_SOURCE, TYPEC_HOST);
	if (ret < 0)
		return ret;

	ret = port->tcpc->set_pd_rx(port->tcpc, true);
	if (ret < 0)
		goto out_disable_mux;

	/*
	 * USB Type-C specification, version 1.2,
	 * chapter 4.5.2.2.8.1 (Attached.SRC Requirements)
	 * Enable VCONN only if the non-RD port is set to RA.
	 */
	if ((polarity == TYPEC_POLARITY_CC1 && port->cc2 == TYPEC_CC_RA) ||
	    (polarity == TYPEC_POLARITY_CC2 && port->cc1 == TYPEC_CC_RA)) {
		ret = tcpm_set_vconn(port, true);
		if (ret < 0)
			goto out_disable_pd;
	}

	ret = tcpm_set_vbus(port, true);
	if (ret < 0)
		goto out_disable_vconn;

	port->pd_capable = false;

	port->partner = NULL;

	port->attached = true;
	port->send_discover = true;

	return 0;

out_disable_vconn:
	tcpm_set_vconn(port, false);
out_disable_pd:
	port->tcpc->set_pd_rx(port->tcpc, false);
out_disable_mux:
	tcpm_mux_set(port, TYPEC_MUX_NONE, TCPC_USB_SWITCH_DISCONNECT);
	return ret;
}

static void tcpm_typec_disconnect(struct tcpm_port *port)
{
	if (port->connected) {
		typec_unregister_partner(port->partner);
		port->partner = NULL;
		port->connected = false;
	}
}

static void tcpm_unregister_altmodes(struct tcpm_port *port)
{
	struct pd_mode_data *modep = &port->mode_data;
	int i;

	for (i = 0; i < modep->altmodes; i++) {
		typec_unregister_altmode(port->partner_altmode[i]);
		port->partner_altmode[i] = NULL;
	}

	memset(modep, 0, sizeof(*modep));
}

static void tcpm_reset_port(struct tcpm_port *port)
{
	tcpm_unregister_altmodes(port);
	tcpm_typec_disconnect(port);
	port->attached = false;
	port->pd_capable = false;

	/*
	 * First Rx ID should be 0; set this to a sentinel of -1 so that
	 * we can check tcpm_pd_rx_handler() if we had seen it before.
	 */
	port->rx_msgid = -1;

	port->tcpc->set_pd_rx(port->tcpc, false);
	tcpm_init_vbus(port);	/* also disables charging */
	tcpm_init_vconn(port);
	tcpm_set_current_limit(port, 0, 0);
	tcpm_set_polarity(port, TYPEC_POLARITY_CC1);
	tcpm_set_attached_state(port, false);
	port->try_src_count = 0;
	port->try_snk_count = 0;
}

static void tcpm_detach(struct tcpm_port *port)
{
	if (!port->attached)
		return;

	if (tcpm_port_is_disconnected(port))
		port->hard_reset_count = 0;

	tcpm_reset_port(port);
}

static void tcpm_src_detach(struct tcpm_port *port)
{
	tcpm_detach(port);
}

static int tcpm_snk_attach(struct tcpm_port *port)
{
	int ret;

	if (port->attached)
		return 0;

	ret = tcpm_set_polarity(port, port->cc2 != TYPEC_CC_OPEN ?
				TYPEC_POLARITY_CC2 : TYPEC_POLARITY_CC1);
	if (ret < 0)
		return ret;

	ret = tcpm_set_roles(port, true, TYPEC_SINK, TYPEC_DEVICE);
	if (ret < 0)
		return ret;

	port->pd_capable = false;

	port->partner = NULL;

	port->attached = true;
	port->send_discover = true;

	return 0;
}

static void tcpm_snk_detach(struct tcpm_port *port)
{
	tcpm_detach(port);

	/* XXX: (Dis)connect SuperSpeed mux? */
}

static int tcpm_acc_attach(struct tcpm_port *port)
{
	int ret;

	if (port->attached)
		return 0;

	ret = tcpm_set_roles(port, true, TYPEC_SOURCE, TYPEC_HOST);
	if (ret < 0)
		return ret;

	port->partner = NULL;

	tcpm_typec_connect(port);

	port->attached = true;

	return 0;
}

static void tcpm_acc_detach(struct tcpm_port *port)
{
	tcpm_detach(port);
}

static inline enum tcpm_state hard_reset_state(struct tcpm_port *port)
{
	if (port->hard_reset_count < PD_N_HARD_RESET_COUNT)
		return HARD_RESET_SEND;
	if (port->pd_capable)
		return ERROR_RECOVERY;
	if (port->pwr_role == TYPEC_SOURCE)
		return SRC_UNATTACHED;
	if (port->state == SNK_WAIT_CAPABILITIES)
		return SNK_READY;
	return SNK_UNATTACHED;
}

static inline enum tcpm_state ready_state(struct tcpm_port *port)
{
	if (port->pwr_role == TYPEC_SOURCE)
		return SRC_READY;
	else
		return SNK_READY;
}

static inline enum tcpm_state unattached_state(struct tcpm_port *port)
{
	if (port->pwr_role == TYPEC_SOURCE)
		return SRC_UNATTACHED;
	else
		return SNK_UNATTACHED;
}

static void tcpm_check_send_discover(struct tcpm_port *port)
{
	if (port->data_role == TYPEC_HOST && port->send_discover &&
	    port->pd_capable) {
		tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0);
		port->send_discover = false;
	}
}

static void tcpm_swap_complete(struct tcpm_port *port, int result)
{
	if (port->swap_pending) {
		port->swap_status = result;
		port->swap_pending = false;
		port->non_pd_role_swap = false;
		complete(&port->swap_complete);
	}
}

static void run_state_machine(struct tcpm_port *port)
{
	int ret;

	port->enter_state = port->state;
	switch (port->state) {
	case DRP_TOGGLING:
		break;
	/* SRC states */
	case SRC_UNATTACHED:
		if (!port->non_pd_role_swap)
			tcpm_swap_complete(port, -ENOTCONN);
		tcpm_src_detach(port);
		if (tcpm_start_drp_toggling(port)) {
			tcpm_set_state(port, DRP_TOGGLING, 0);
			break;
		}
		tcpm_set_cc(port, tcpm_rp_cc(port));
		if (port->port_type == TYPEC_PORT_DRP)
			tcpm_set_state(port, SNK_UNATTACHED, PD_T_DRP_SNK);
		break;
	case SRC_ATTACH_WAIT:
		if (tcpm_port_is_debug(port))
			tcpm_set_state(port, DEBUG_ACC_ATTACHED,
				       PD_T_CC_DEBOUNCE);
		else if (tcpm_port_is_audio(port))
			tcpm_set_state(port, AUDIO_ACC_ATTACHED,
				       PD_T_CC_DEBOUNCE);
		else if (tcpm_port_is_source(port))
			tcpm_set_state(port,
				       tcpm_try_snk(port) ? SNK_TRY
							  : SRC_ATTACHED,
				       PD_T_CC_DEBOUNCE);
		break;

	case SNK_TRY:
		port->try_snk_count++;
		/*
		 * Requirements:
		 * - Do not drive vconn or vbus
		 * - Terminate CC pins (both) to Rd
		 * Action:
		 * - Wait for tDRPTry (PD_T_DRP_TRY).
		 *   Until then, ignore any state changes.
		 */
		tcpm_set_cc(port, TYPEC_CC_RD);
		tcpm_set_state(port, SNK_TRY_WAIT, PD_T_DRP_TRY);
		break;
	case SNK_TRY_WAIT:
		if (tcpm_port_is_sink(port)) {
			tcpm_set_state(port, SNK_TRY_WAIT_DEBOUNCE, 0);
		} else {
			tcpm_set_state(port, SRC_TRYWAIT, 0);
			port->max_wait = 0;
		}
		break;
	case SNK_TRY_WAIT_DEBOUNCE:
		tcpm_set_state(port, SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS,
			       PD_T_PD_DEBOUNCE);
		break;
	case SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS:
		if (port->vbus_present && tcpm_port_is_sink(port))
			tcpm_set_state(port, SNK_ATTACHED, 0);
		else {
			tcpm_set_state(port, SRC_TRYWAIT, 0);
			port->max_wait = 0;
		}
		break;
	case SRC_TRYWAIT:
		tcpm_set_cc(port, tcpm_rp_cc(port));
		if (port->max_wait == 0) {
			port->max_wait = jiffies +
					 msecs_to_jiffies(PD_T_DRP_TRY);
			tcpm_set_state(port, SRC_TRYWAIT_UNATTACHED,
				       PD_T_DRP_TRY);
		} else {
			if (time_is_after_jiffies(port->max_wait))
				tcpm_set_state(port, SRC_TRYWAIT_UNATTACHED,
					       jiffies_to_msecs(
					       port->max_wait - jiffies));
			else
				tcpm_set_state(port, SNK_UNATTACHED, 0);
		}
		break;
	case SRC_TRYWAIT_DEBOUNCE:
		tcpm_set_state(port, SRC_ATTACHED, PD_T_CC_DEBOUNCE);
		break;
	case SRC_TRYWAIT_UNATTACHED:
		tcpm_set_state(port, SNK_UNATTACHED, 0);
		break;

	case SRC_ATTACHED:
		ret = tcpm_src_attach(port);
		tcpm_set_state(port, SRC_UNATTACHED,
			       ret < 0 ? 0 : PD_T_PS_SOURCE_ON);
		break;
	case SRC_STARTUP:
		typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_USB);
		port->pwr_opmode = TYPEC_PWR_MODE_USB;
		port->caps_count = 0;
		port->message_id = 0;
		port->rx_msgid = -1;
		port->explicit_contract = false;
		IsPRSwap = false;
		tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
		break;
	case SRC_SEND_CAPABILITIES:
		port->caps_count++;
		if (port->caps_count > PD_N_CAPS_COUNT) {
			tcpm_set_state(port, SRC_READY, 0);
			break;
		}
		ret = tcpm_pd_send_source_caps(port);
		if (ret < 0) {
			tcpm_set_state(port, SRC_SEND_CAPABILITIES,
				       PD_T_SEND_SOURCE_CAP);
		} else {
			/*
			 * Per standard, we should clear the reset counter here.
			 * However, that can result in state machine hang-ups.
			 * Reset it only in READY state to improve stability.
			 */
			/* port->hard_reset_count = 0; */
			port->caps_count = 0;
			port->pd_capable = true;
			tcpm_set_state_cond(port, hard_reset_state(port),
					    PD_T_SEND_SOURCE_CAP);
		}
		break;
	case SRC_NEGOTIATE_CAPABILITIES:
		ret = tcpm_pd_check_request(port);
		if (ret < 0) {
			tcpm_pd_send_control(port, PD_CTRL_REJECT);
			if (!port->explicit_contract) {
				tcpm_set_state(port,
					       SRC_WAIT_NEW_CAPABILITIES, 0);
			} else {
				tcpm_set_state(port, SRC_READY, 0);
			}
		} else {
			tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
			tcpm_set_state(port, SRC_TRANSITION_SUPPLY,
				       PD_T_SRC_TRANSITION);
		}
		break;
	case SRC_TRANSITION_SUPPLY:
		/* XXX: regulator_set_voltage(vbus, ...) */
		tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
		port->explicit_contract = true;
		typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_PD);
		port->pwr_opmode = TYPEC_PWR_MODE_PD;
		tcpm_set_state_cond(port, SRC_READY, 0);
		break;
	case SRC_READY:
#if 1
		port->hard_reset_count = 0;
#endif
		port->try_src_count = 0;

		tcpm_swap_complete(port, 0);
		tcpm_typec_connect(port);
		tcpm_check_send_discover(port);
		/*
		 * 6.3.5
		 * Sending ping messages is not necessary if
		 * - the source operates at vSafe5V
		 * or
		 * - The system is not operating in PD mode
		 * or
		 * - Both partners are connected using a Type-C connector
		 *   XXX How do we know that ?
		 */
		if (port->pwr_opmode == TYPEC_PWR_MODE_PD &&
		    !port->op_vsafe5v) {
			tcpm_pd_send_control(port, PD_CTRL_PING);
			tcpm_set_state_cond(port, SRC_READY,
					    PD_T_SOURCE_ACTIVITY);
		}
		break;
	case SRC_WAIT_NEW_CAPABILITIES:
		/* Nothing to do... */
		break;

	/* SNK states */
	case SNK_UNATTACHED:
		if (!port->non_pd_role_swap)
			tcpm_swap_complete(port, -ENOTCONN);
		tcpm_snk_detach(port);
		if (tcpm_start_drp_toggling(port)) {
			tcpm_set_state(port, DRP_TOGGLING, 0);
			break;
		}
		tcpm_set_cc(port, TYPEC_CC_RD);
		if (port->port_type == TYPEC_PORT_DRP)
			tcpm_set_state(port, SRC_UNATTACHED, PD_T_DRP_SRC);
		break;
	case SNK_ATTACH_WAIT:
		if ((port->cc1 == TYPEC_CC_OPEN &&
		     port->cc2 != TYPEC_CC_OPEN) ||
		    (port->cc1 != TYPEC_CC_OPEN &&
		     port->cc2 == TYPEC_CC_OPEN))
			tcpm_set_state(port, SNK_DEBOUNCED,
				       PD_T_CC_DEBOUNCE);
		else if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, SNK_UNATTACHED,
				       PD_T_PD_DEBOUNCE);
		break;
	case SNK_DEBOUNCED:
		if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, SNK_UNATTACHED,
				       PD_T_PD_DEBOUNCE);
		else if (port->vbus_present)
			tcpm_set_state(port,
				       tcpm_try_src(port) ? SRC_TRY
							  : SNK_ATTACHED,
				       0);
		else
			/* Wait for VBUS, but not forever */
			tcpm_set_state(port, SNK_UNATTACHED, PD_T_PS_SOURCE_ON);
		break;

	case SRC_TRY:
		port->try_src_count++;
		tcpm_set_cc(port, tcpm_rp_cc(port));
		tcpm_set_state(port, SNK_TRYWAIT, PD_T_DRP_TRY);
		break;
	case SRC_TRY_DEBOUNCE:
		tcpm_set_state(port, SRC_ATTACHED, PD_T_PD_DEBOUNCE);
		break;
	case SNK_TRYWAIT:
		tcpm_set_cc(port, TYPEC_CC_RD);
		tcpm_set_state(port, SNK_TRYWAIT_DEBOUNCE, PD_T_CC_DEBOUNCE);
		break;
	case SNK_TRYWAIT_DEBOUNCE:
		if (port->vbus_present) {
			tcpm_set_state(port, SNK_ATTACHED, 0);
			break;
		}
		if (tcpm_port_is_disconnected(port)) {
			tcpm_set_state(port, SNK_UNATTACHED,
				       PD_T_PD_DEBOUNCE);
			break;
		}
		if (tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_ATTACHED, 0);
		/* XXX Are we supposed to stay in this state ? */
		break;
	case SNK_TRYWAIT_VBUS:
		tcpm_set_state(port, SNK_ATTACHED, PD_T_CC_DEBOUNCE);
		break;

	case SNK_ATTACHED:
		ret = tcpm_snk_attach(port);
		if (ret < 0)
			tcpm_set_state(port, SNK_UNATTACHED, 0);
		else
			tcpm_set_state(port, SNK_STARTUP, 0);
		break;
	case SNK_STARTUP:
		/* XXX: callback into infrastructure */
		typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_USB);
		port->pwr_opmode = TYPEC_PWR_MODE_USB;
		port->message_id = 0;
		port->rx_msgid = -1;
		port->explicit_contract = false;
		IsPRSwap = false;
		tcpm_set_state(port, SNK_DISCOVERY, 0);
		break;
	case SNK_DISCOVERY:
		if (port->vbus_present) {
			tcpm_set_current_limit(port,
					       tcpm_get_current_limit(port),
					       5000);
			tcpm_set_charge(port, true);
			tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
			break;
		}
		/*
		 * For DRP, timeouts differ. Also, handling is supposed to be
		 * different and much more complex (dead battery detection;
		 * see USB power delivery specification, section 8.3.3.6.1.5.1).
		 */
		tcpm_set_state(port, hard_reset_state(port),
			       port->port_type == TYPEC_PORT_DRP ?
					PD_T_DB_DETECT : PD_T_NO_RESPONSE);
		break;
	case SNK_DISCOVERY_DEBOUNCE:
		tcpm_set_state(port, SNK_DISCOVERY_DEBOUNCE_DONE,
			       PD_T_CC_DEBOUNCE);
		break;
	case SNK_DISCOVERY_DEBOUNCE_DONE:
		if (!tcpm_port_is_disconnected(port) &&
		    tcpm_port_is_sink(port) &&
		    time_is_after_jiffies(port->delayed_runtime)) {
			tcpm_set_state(port, SNK_DISCOVERY,
				       port->delayed_runtime - jiffies);
			break;
		}
		tcpm_set_state(port, unattached_state(port), 0);
		break;
	case SNK_WAIT_CAPABILITIES:
		ret = port->tcpc->set_pd_rx(port->tcpc, true);
		if (ret < 0) {
			tcpm_set_state(port, SNK_READY, 0);
			break;
		}
		/*
		 * If VBUS has never been low, and we time out waiting
		 * for source cap, try a soft reset first, in case we
		 * were already in a stable contract before this boot.
		 * Do this only once.
		 */
		if (port->vbus_never_low) {
			port->vbus_never_low = false;
			tcpm_set_state(port, SOFT_RESET_SEND,
				       PD_T_SINK_WAIT_CAP);
		} else {
			tcpm_set_state(port, hard_reset_state(port),
				       PD_T_SINK_WAIT_CAP);
		}
		break;
	case SNK_NEGOTIATE_CAPABILITIES:
		port->pd_capable = true;
		port->hard_reset_count = 0;
		ret = tcpm_pd_send_request(port);
		if (ret < 0) {
			/* Let the Source send capabilities again. */
			tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
		} else {
			tcpm_set_state_cond(port, hard_reset_state(port),
					    PD_T_SENDER_RESPONSE);
		}
		break;
	case SNK_TRANSITION_SINK:
	case SNK_TRANSITION_SINK_VBUS:
		tcpm_set_state(port, hard_reset_state(port),
			       PD_T_PS_TRANSITION);
		break;
	case SNK_READY:
		port->try_snk_count = 0;
		port->explicit_contract = true;
		typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_PD);
		port->pwr_opmode = TYPEC_PWR_MODE_PD;

		tcpm_swap_complete(port, 0);
		tcpm_typec_connect(port);
		tcpm_check_send_discover(port);
		break;

	/* Accessory states */
	case ACC_UNATTACHED:
		tcpm_acc_detach(port);
		tcpm_set_state(port, SRC_UNATTACHED, 0);
		break;
	case DEBUG_ACC_ATTACHED:
	case AUDIO_ACC_ATTACHED:
		ret = tcpm_acc_attach(port);
		if (ret < 0)
			tcpm_set_state(port, ACC_UNATTACHED, 0);
		break;
	case AUDIO_ACC_DEBOUNCE:
		tcpm_set_state(port, ACC_UNATTACHED, PD_T_CC_DEBOUNCE);
		break;

	/* Hard_Reset states */
	case HARD_RESET_SEND:
		tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
		tcpm_set_state(port, HARD_RESET_START, 0);
		break;
	case HARD_RESET_START:
		port->hard_reset_count++;
		port->tcpc->set_pd_rx(port->tcpc, false);
		tcpm_unregister_altmodes(port);
		port->send_discover = true;
		if (port->pwr_role == TYPEC_SOURCE)
			tcpm_set_state(port, SRC_HARD_RESET_VBUS_OFF,
				       PD_T_PS_HARD_RESET);
		else
			tcpm_set_state(port, SNK_HARD_RESET_SINK_OFF, 0);
		break;
	case SRC_HARD_RESET_VBUS_OFF:
		tcpm_set_vconn(port, true);
		tcpm_set_vbus(port, false);
		tcpm_set_roles(port, false, TYPEC_SOURCE, TYPEC_HOST);
		tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, PD_T_SRC_RECOVER);
		break;
	case SRC_HARD_RESET_VBUS_ON:
		tcpm_set_vbus(port, true);
		port->tcpc->set_pd_rx(port->tcpc, true);
		tcpm_set_attached_state(port, true);
		tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
		break;
	case SNK_HARD_RESET_SINK_OFF:
		tcpm_set_vconn(port, false);
		tcpm_set_charge(port, false);
		tcpm_set_roles(port, false, TYPEC_SINK, TYPEC_DEVICE);
		/*
		 * VBUS may or may not toggle, depending on the adapter.
		 * If it doesn't toggle, transition to SNK_HARD_RESET_SINK_ON
		 * directly after timeout.
		 */
		tcpm_set_state(port, SNK_HARD_RESET_SINK_ON, PD_T_SAFE_0V);
		break;
	case SNK_HARD_RESET_WAIT_VBUS:
		/* Assume we're disconnected if VBUS doesn't come back. */
		tcpm_set_state(port, SNK_UNATTACHED,
			       PD_T_SRC_RECOVER_MAX + PD_T_SRC_TURN_ON);
		break;
	case SNK_HARD_RESET_SINK_ON:
		/* Note: There is no guarantee that VBUS is on in this state */
		/*
		 * XXX:
		 * The specification suggests that dual mode ports in sink
		 * mode should transition to state PE_SRC_Transition_to_default.
		 * See USB power delivery specification chapter 8.3.3.6.1.3.
		 * This would mean to to
		 * - turn off VCONN, reset power supply
		 * - request hardware reset
		 * - turn on VCONN
		 * - Transition to state PE_Src_Startup
		 * SNK only ports shall transition to state Snk_Startup
		 * (see chapter 8.3.3.3.8).
		 * Similar, dual-mode ports in source mode should transition
		 * to PE_SNK_Transition_to_default.
		 */
		tcpm_set_attached_state(port, true);
		tcpm_set_state(port, SNK_STARTUP, 0);
		break;

	/* Soft_Reset states */
	case SOFT_RESET:
		port->message_id = 0;
		port->rx_msgid = -1;
		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
		if (port->pwr_role == TYPEC_SOURCE)
			tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
		else
			tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
		break;
	case SOFT_RESET_SEND:
		port->message_id = 0;
		port->rx_msgid = -1;
		if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET))
			tcpm_set_state_cond(port, hard_reset_state(port), 0);
		else
			tcpm_set_state_cond(port, hard_reset_state(port),
					    PD_T_SENDER_RESPONSE);
		break;

	/* DR_Swap states */
	case DR_SWAP_SEND:
		tcpm_pd_send_control(port, PD_CTRL_DR_SWAP);
		tcpm_set_state_cond(port, DR_SWAP_SEND_TIMEOUT,
				    PD_T_SENDER_RESPONSE);
		break;
	case DR_SWAP_ACCEPT:
		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
		tcpm_set_state_cond(port, DR_SWAP_CHANGE_DR, 0);
		break;
	case DR_SWAP_SEND_TIMEOUT:
		tcpm_swap_complete(port, -ETIMEDOUT);
		tcpm_set_state(port, ready_state(port), 0);
		break;
	case DR_SWAP_CHANGE_DR:
		if (port->data_role == TYPEC_HOST) {
			tcpm_unregister_altmodes(port);
			tcpm_set_roles(port, true, port->pwr_role,
				       TYPEC_DEVICE);
		} else {
			tcpm_set_roles(port, true, port->pwr_role,
				       TYPEC_HOST);
			port->send_discover = true;
		}
		tcpm_set_state(port, ready_state(port), 0);
		break;

	/* PR_Swap states */
	case PR_SWAP_ACCEPT:
		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
		tcpm_set_state(port, PR_SWAP_START, 0);
		break;
	case PR_SWAP_SEND:
		tcpm_pd_send_control(port, PD_CTRL_PR_SWAP);
		tcpm_set_state_cond(port, PR_SWAP_SEND_TIMEOUT,
				    PD_T_SENDER_RESPONSE);
		break;
	case PR_SWAP_SEND_TIMEOUT:
		tcpm_swap_complete(port, -ETIMEDOUT);
		tcpm_set_state(port, ready_state(port), 0);
		break;
	case PR_SWAP_START:
		IsPRSwap = true;
		if (port->pwr_role == TYPEC_SOURCE)
			tcpm_set_state(port, PR_SWAP_SRC_SNK_TRANSITION_OFF,
				       PD_T_SRC_TRANSITION);
		else
			tcpm_set_state(port, PR_SWAP_SNK_SRC_SINK_OFF, 0);
		break;
	case PR_SWAP_SRC_SNK_TRANSITION_OFF:
		tcpm_set_vbus(port, false);
		port->explicit_contract = false;
		tcpm_set_state(port, PR_SWAP_SRC_SNK_SOURCE_OFF,
			       PD_T_PS_SOURCE_OFF);
		break;
	case PR_SWAP_SRC_SNK_SOURCE_OFF:
		tcpm_set_cc(port, TYPEC_CC_RD);
		/*
		 * USB-PD standard, 6.2.1.4, Port Power Role:
		 * "During the Power Role Swap Sequence, for the initial Source
		 * Port, the Port Power Role field shall be set to Sink in the
		 * PS_RDY Message indicating that the initial Source’s power
		 * supply is turned off"
		 */
		tcpm_set_pwr_role(port, TYPEC_SINK);
		if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY)) {
			tcpm_set_state(port, ERROR_RECOVERY, 0);
			break;
		}
		tcpm_set_state_cond(port, SNK_UNATTACHED, PD_T_PS_SOURCE_ON);
		break;
	case PR_SWAP_SRC_SNK_SINK_ON:
		tcpm_set_state(port, SNK_STARTUP, 0);
		break;
	case PR_SWAP_SNK_SRC_SINK_OFF:
		tcpm_set_charge(port, false);
		tcpm_set_state(port, hard_reset_state(port),
			       PD_T_PS_SOURCE_OFF);
		break;
	case PR_SWAP_SNK_SRC_SOURCE_ON:
		tcpm_set_cc(port, tcpm_rp_cc(port));
		tcpm_set_vbus(port, true);
		/*
		 * USB PD standard, 6.2.1.4:
		 * "Subsequent Messages initiated by the Policy Engine,
		 * such as the PS_RDY Message sent to indicate that Vbus
		 * is ready, will have the Port Power Role field set to
		 * Source."
		 */
		tcpm_set_pwr_role(port, TYPEC_SOURCE);
		tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
		tcpm_set_state(port, SRC_STARTUP, 0);
		break;

	case VCONN_SWAP_ACCEPT:
		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
		tcpm_set_state(port, VCONN_SWAP_START, 0);
		break;
	case VCONN_SWAP_SEND:
		tcpm_pd_send_control(port, PD_CTRL_VCONN_SWAP);
		tcpm_set_state(port, VCONN_SWAP_SEND_TIMEOUT,
			       PD_T_SENDER_RESPONSE);
		break;
	case VCONN_SWAP_SEND_TIMEOUT:
		tcpm_swap_complete(port, -ETIMEDOUT);
		tcpm_set_state(port, ready_state(port), 0);
		break;
	case VCONN_SWAP_START:
		if (port->vconn_role == TYPEC_SOURCE)
			tcpm_set_state(port, VCONN_SWAP_WAIT_FOR_VCONN, 0);
		else
			tcpm_set_state(port, VCONN_SWAP_TURN_ON_VCONN, 0);
		break;
	case VCONN_SWAP_WAIT_FOR_VCONN:
		tcpm_set_state(port, hard_reset_state(port),
			       PD_T_VCONN_SOURCE_ON);
		break;
	case VCONN_SWAP_TURN_ON_VCONN:
		tcpm_set_vconn(port, true);
		tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
		tcpm_set_state(port, ready_state(port), 0);
		break;
	case VCONN_SWAP_TURN_OFF_VCONN:
		tcpm_set_vconn(port, false);
		tcpm_set_state(port, ready_state(port), 0);
		break;

	case DR_SWAP_CANCEL:
	case PR_SWAP_CANCEL:
	case VCONN_SWAP_CANCEL:
		tcpm_swap_complete(port, port->swap_status);
		IsPRSwap = false;
		if (port->pwr_role == TYPEC_SOURCE)
			tcpm_set_state(port, SRC_READY, 0);
		else
			tcpm_set_state(port, SNK_READY, 0);
		break;

	case BIST_RX:
		switch (BDO_MODE_MASK(port->bist_request)) {
		case BDO_MODE_CARRIER2:
			tcpm_pd_transmit(port, TCPC_TX_BIST_MODE_2, NULL);
			break;
		default:
			break;
		}
		/* Always switch to unattached state */
		tcpm_set_state(port, unattached_state(port), 0);
		break;
	case ERROR_RECOVERY:
		IsPRSwap = false;
		tcpm_swap_complete(port, -EPROTO);
		tcpm_set_state(port, PORT_RESET, 0);
		break;
	case PORT_RESET:
		tcpm_reset_port(port);
		tcpm_set_cc(port, TYPEC_CC_OPEN);
		tcpm_set_state(port, PORT_RESET_WAIT_OFF,
			       PD_T_ERROR_RECOVERY);
		break;
	case PORT_RESET_WAIT_OFF:
		tcpm_set_state(port,
			       tcpm_default_state(port),
			       port->vbus_present ? PD_T_PS_SOURCE_OFF : 0);
		break;
	default:
		WARN(1, "Unexpected port state %d\n", port->state);
		break;
	}
}

static void tcpm_state_machine_work(struct work_struct *work)
{
	struct tcpm_port *port = container_of(work, struct tcpm_port,
					      state_machine.work);
	enum tcpm_state prev_state;

	mutex_lock(&port->lock);
	port->state_machine_running = true;

	if (port->queued_message && tcpm_send_queued_message(port))
		goto done;

	/* If we were queued due to a delayed state change, update it now */
	if (port->delayed_state) {
		tcpm_log(port, "state change %s -> %s [delayed %ld ms]",
			 tcpm_states[port->state],
			 tcpm_states[port->delayed_state], port->delay_ms);
		port->prev_state = port->state;
		port->state = port->delayed_state;
		port->delayed_state = INVALID_STATE;
	}

	/*
	 * Continue running as long as we have (non-delayed) state changes
	 * to make.
	 */
	do {
		prev_state = port->state;
		run_state_machine(port);
		if (port->queued_message)
			tcpm_send_queued_message(port);
	} while (port->state != prev_state && !port->delayed_state);

done:
	port->state_machine_running = false;
	mutex_unlock(&port->lock);
}

static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
			    enum typec_cc_status cc2)
{
	enum typec_cc_status old_cc1, old_cc2;
	enum tcpm_state new_state;

	old_cc1 = port->cc1;
	old_cc2 = port->cc2;
	port->cc1 = cc1;
	port->cc2 = cc2;

	tcpm_log_force(port,
		       "CC1: %u -> %u, CC2: %u -> %u [state %s, polarity %d, %s]",
		       old_cc1, cc1, old_cc2, cc2, tcpm_states[port->state],
		       port->polarity,
		       tcpm_port_is_disconnected(port) ? "disconnected"
						       : "connected");

	switch (port->state) {
	case DRP_TOGGLING:
		if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
		    tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
		else if (tcpm_port_is_sink(port))
			tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
		break;
	case SRC_UNATTACHED:
	case ACC_UNATTACHED:
		if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
		    tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
		break;
	case SRC_ATTACH_WAIT:
		if (tcpm_port_is_disconnected(port) ||
		    tcpm_port_is_audio_detached(port))
			tcpm_set_state(port, SRC_UNATTACHED, 0);
		else if (cc1 != old_cc1 || cc2 != old_cc2)
			tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
		break;
	case SRC_ATTACHED:
		if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, SRC_UNATTACHED, 0);
		break;

	case SNK_UNATTACHED:
		if (tcpm_port_is_sink(port))
			tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
		break;
	case SNK_ATTACH_WAIT:
		if ((port->cc1 == TYPEC_CC_OPEN &&
		     port->cc2 != TYPEC_CC_OPEN) ||
		    (port->cc1 != TYPEC_CC_OPEN &&
		     port->cc2 == TYPEC_CC_OPEN))
			new_state = SNK_DEBOUNCED;
		else if (tcpm_port_is_disconnected(port))
			new_state = SNK_UNATTACHED;
		else
			break;
		if (new_state != port->delayed_state)
			tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
		break;
	case SNK_DEBOUNCED:
		if (tcpm_port_is_disconnected(port))
			new_state = SNK_UNATTACHED;
		else if (port->vbus_present)
			new_state = tcpm_try_src(port) ? SRC_TRY : SNK_ATTACHED;
		else
			new_state = SNK_UNATTACHED;
		if (new_state != port->delayed_state)
			tcpm_set_state(port, SNK_DEBOUNCED, 0);
		break;
	case SNK_READY:
		if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, unattached_state(port), 0);
		else if (!port->pd_capable &&
			 (cc1 != old_cc1 || cc2 != old_cc2))
			tcpm_set_current_limit(port,
					       tcpm_get_current_limit(port),
					       5000);
		break;

	case AUDIO_ACC_ATTACHED:
		if (cc1 == TYPEC_CC_OPEN || cc2 == TYPEC_CC_OPEN)
			tcpm_set_state(port, AUDIO_ACC_DEBOUNCE, 0);
		break;
	case AUDIO_ACC_DEBOUNCE:
		if (tcpm_port_is_audio(port))
			tcpm_set_state(port, AUDIO_ACC_ATTACHED, 0);
		break;

	case DEBUG_ACC_ATTACHED:
		if (cc1 == TYPEC_CC_OPEN || cc2 == TYPEC_CC_OPEN)
			tcpm_set_state(port, ACC_UNATTACHED, 0);
		break;

	case SNK_TRY:
		/* Do nothing, waiting for timeout */
		break;

	case SNK_DISCOVERY:
		/* CC line is unstable, wait for debounce */
		if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, SNK_DISCOVERY_DEBOUNCE, 0);
		break;
	case SNK_DISCOVERY_DEBOUNCE:
		break;

	case SRC_TRYWAIT:
		/* Hand over to state machine if needed */
		if (!port->vbus_present && tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_TRYWAIT_DEBOUNCE, 0);
		break;
	case SRC_TRYWAIT_DEBOUNCE:
		if (port->vbus_present || !tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_TRYWAIT, 0);
		break;
	case SNK_TRY_WAIT_DEBOUNCE:
		if (!tcpm_port_is_sink(port)) {
			port->max_wait = 0;
			tcpm_set_state(port, SRC_TRYWAIT, 0);
		}
		break;
	case SRC_TRY:
		if (tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_TRY_DEBOUNCE, 0);
		break;
	case SRC_TRY_DEBOUNCE:
		tcpm_set_state(port, SRC_TRY, 0);
		break;
	case SNK_TRYWAIT_DEBOUNCE:
		if (port->vbus_present) {
			tcpm_set_state(port, SNK_ATTACHED, 0);
			break;
		}
		if (tcpm_port_is_source(port)) {
			tcpm_set_state(port, SRC_ATTACHED, 0);
			break;
		}
		if (tcpm_port_is_disconnected(port) &&
		    port->delayed_state != SNK_UNATTACHED)
			tcpm_set_state(port, SNK_TRYWAIT_DEBOUNCE, 0);
		break;

	case PR_SWAP_SNK_SRC_SINK_OFF:
	case PR_SWAP_SRC_SNK_TRANSITION_OFF:
	case PR_SWAP_SRC_SNK_SOURCE_OFF:
		/*
		 * CC state change is expected here; we just turned off power.
		 * Ignore it.
		 */
		break;

	default:
		if (tcpm_port_is_disconnected(port))
			tcpm_set_state(port, unattached_state(port), 0);
		break;
	}
}

static void _tcpm_pd_vbus_on(struct tcpm_port *port)
{
	tcpm_log_force(port, "VBUS on");
	port->vbus_present = true;
	switch (port->state) {
	case SNK_TRANSITION_SINK_VBUS:
		tcpm_set_state(port, SNK_READY, 0);
		break;
	case SNK_DISCOVERY:
		tcpm_set_state(port, SNK_DISCOVERY, 0);
		break;

	case SNK_DEBOUNCED:
		tcpm_set_state(port, tcpm_try_src(port) ? SRC_TRY
							: SNK_ATTACHED,
				       0);
		break;
	case SNK_HARD_RESET_WAIT_VBUS:
		tcpm_set_state(port, SNK_HARD_RESET_SINK_ON, 0);
		break;
	case SRC_ATTACHED:
		tcpm_set_state(port, SRC_STARTUP, 0);
		break;
	case SRC_HARD_RESET_VBUS_ON:
		tcpm_set_state(port, SRC_STARTUP, 0);
		break;

	case SNK_TRY:
		/* Do nothing, waiting for timeout */
		break;
	case SRC_TRYWAIT:
		/* Do nothing, Waiting for Rd to be detected */
		break;
	case SRC_TRYWAIT_DEBOUNCE:
		tcpm_set_state(port, SRC_TRYWAIT, 0);
		break;
	case SNK_TRY_WAIT_DEBOUNCE:
		/* Do nothing, waiting for PD_DEBOUNCE to do be done */
		break;
	case SNK_TRYWAIT:
		tcpm_set_state(port, SNK_TRYWAIT_VBUS, 0);
		break;

	default:
		break;
	}
}

static void _tcpm_pd_vbus_off(struct tcpm_port *port)
{
	tcpm_log_force(port, "VBUS off");
	port->vbus_present = false;
	port->vbus_never_low = false;
	switch (port->state) {
	case SNK_HARD_RESET_SINK_OFF:
		tcpm_set_state(port, SNK_HARD_RESET_WAIT_VBUS, 0);
		break;
	case SRC_HARD_RESET_VBUS_OFF:
		tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, 0);
		break;
	case HARD_RESET_SEND:
		break;

	case SNK_TRY:
		/* Do nothing, waiting for timeout */
		break;
	case SRC_TRYWAIT:
		/* Hand over to state machine if needed */
		if (tcpm_port_is_source(port))
			tcpm_set_state(port, SRC_TRYWAIT_DEBOUNCE, 0);
		break;
	case SNK_TRY_WAIT_DEBOUNCE:
		/* Do nothing, waiting for PD_DEBOUNCE to do be done */
		break;
	case SNK_TRYWAIT_VBUS:
		tcpm_set_state(port, SNK_TRYWAIT, 0);
		break;

	case SNK_ATTACH_WAIT:
		tcpm_set_state(port, SNK_UNATTACHED, 0);
		break;

	case SNK_NEGOTIATE_CAPABILITIES:
		break;

	case PR_SWAP_SRC_SNK_TRANSITION_OFF:
		tcpm_set_state(port, PR_SWAP_SRC_SNK_SOURCE_OFF, 0);
		break;

	case PR_SWAP_SNK_SRC_SINK_OFF:
		/* Do nothing, expected */
		break;

	case PORT_RESET_WAIT_OFF:
		tcpm_set_state(port, tcpm_default_state(port), 0);
		break;

	default:
		if (port->pwr_role == TYPEC_SINK &&
		    port->attached)
			tcpm_set_state(port, SNK_UNATTACHED, 0);
		break;
	}
}

static void _tcpm_pd_hard_reset(struct tcpm_port *port)
{
	tcpm_log_force(port, "Received hard reset");
	/*
	 * If we keep receiving hard reset requests, executing the hard reset
	 * must have failed. Revert to error recovery if that happens.
	 */
	tcpm_set_state(port,
		       port->hard_reset_count < PD_N_HARD_RESET_COUNT ?
				HARD_RESET_START : ERROR_RECOVERY,
		       0);
}

static void tcpm_pd_event_handler(struct work_struct *work)
{
	struct tcpm_port *port = container_of(work, struct tcpm_port,
					      event_work);
	u32 events;

	mutex_lock(&port->lock);

	spin_lock(&port->pd_event_lock);
	while (port->pd_events) {
		events = port->pd_events;
		port->pd_events = 0;
		spin_unlock(&port->pd_event_lock);
		if (events & TCPM_RESET_EVENT)
			_tcpm_pd_hard_reset(port);
		if (events & TCPM_VBUS_EVENT) {
			bool vbus;

			vbus = port->tcpc->get_vbus(port->tcpc);
			if (vbus)
				_tcpm_pd_vbus_on(port);
			else
				_tcpm_pd_vbus_off(port);
		}
		if (events & TCPM_CC_EVENT) {
			enum typec_cc_status cc1, cc2;

			if (port->tcpc->get_cc(port->tcpc, &cc1, &cc2) == 0)
				_tcpm_cc_change(port, cc1, cc2);
		}
		spin_lock(&port->pd_event_lock);
	}
	spin_unlock(&port->pd_event_lock);
	mutex_unlock(&port->lock);
}

void tcpm_cc_change(struct tcpm_port *port)
{
	spin_lock(&port->pd_event_lock);
	port->pd_events |= TCPM_CC_EVENT;
	spin_unlock(&port->pd_event_lock);
	queue_work(port->wq, &port->event_work);
}
EXPORT_SYMBOL_GPL(tcpm_cc_change);

void tcpm_vbus_change(struct tcpm_port *port)
{
	spin_lock(&port->pd_event_lock);
	port->pd_events |= TCPM_VBUS_EVENT;
	spin_unlock(&port->pd_event_lock);
	queue_work(port->wq, &port->event_work);
}
EXPORT_SYMBOL_GPL(tcpm_vbus_change);

void tcpm_pd_hard_reset(struct tcpm_port *port)
{
	spin_lock(&port->pd_event_lock);
	port->pd_events = TCPM_RESET_EVENT;
	spin_unlock(&port->pd_event_lock);
	queue_work(port->wq, &port->event_work);
}
EXPORT_SYMBOL_GPL(tcpm_pd_hard_reset);

static int tcpm_dr_set(const struct typec_capability *cap,
		       enum typec_data_role data)
{
	struct tcpm_port *port = typec_cap_to_tcpm(cap);
	int ret;

	mutex_lock(&port->swap_lock);
	mutex_lock(&port->lock);

	if (port->port_type != TYPEC_PORT_DRP) {
		ret = -EINVAL;
		goto port_unlock;
	}
	if (port->state != SRC_READY && port->state != SNK_READY) {
		ret = -EAGAIN;
		goto port_unlock;
	}

	if (port->data_role == data) {
		ret = 0;
		goto port_unlock;
	}

	/*
	 * XXX
	 * 6.3.9: If an alternate mode is active, a request to swap
	 * alternate modes shall trigger a port reset.
	 * Reject data role swap request in this case.
	 */

	if (!port->pd_capable) {
		/*
		 * If the partner is not PD capable, reset the port to
		 * trigger a role change. This can only work if a preferred
		 * role is configured, and if it matches the requested role.
		 */
		if (port->try_role == TYPEC_NO_PREFERRED_ROLE ||
		    port->try_role == port->pwr_role) {
			ret = -EINVAL;
			goto port_unlock;
		}
		port->non_pd_role_swap = true;
		tcpm_set_state(port, PORT_RESET, 0);
	} else {
		tcpm_set_state(port, DR_SWAP_SEND, 0);
	}

	port->swap_status = 0;
	port->swap_pending = true;
	reinit_completion(&port->swap_complete);
	mutex_unlock(&port->lock);

	if (!wait_for_completion_timeout(&port->swap_complete,
				msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
		ret = -ETIMEDOUT;
	else
		ret = port->swap_status;

	port->non_pd_role_swap = false;
	goto swap_unlock;

port_unlock:
	mutex_unlock(&port->lock);
swap_unlock:
	mutex_unlock(&port->swap_lock);
	return ret;
}

static int tcpm_pr_set(const struct typec_capability *cap,
		       enum typec_role role)
{
	struct tcpm_port *port = typec_cap_to_tcpm(cap);
	int ret;

	mutex_lock(&port->swap_lock);
	mutex_lock(&port->lock);

	if (port->port_type != TYPEC_PORT_DRP) {
		ret = -EINVAL;
		goto port_unlock;
	}
	if (port->state != SRC_READY && port->state != SNK_READY) {
		ret = -EAGAIN;
		goto port_unlock;
	}

	if (role == port->pwr_role) {
		ret = 0;
		goto port_unlock;
	}

	port->swap_status = 0;
	port->swap_pending = true;
	reinit_completion(&port->swap_complete);
	tcpm_set_state(port, PR_SWAP_SEND, 0);
	mutex_unlock(&port->lock);

	if (!wait_for_completion_timeout(&port->swap_complete,
				msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
		ret = -ETIMEDOUT;
	else
		ret = port->swap_status;

	goto swap_unlock;

port_unlock:
	mutex_unlock(&port->lock);
swap_unlock:
	mutex_unlock(&port->swap_lock);
	return ret;
}

static int tcpm_vconn_set(const struct typec_capability *cap,
			  enum typec_role role)
{
	struct tcpm_port *port = typec_cap_to_tcpm(cap);
	int ret;

	mutex_lock(&port->swap_lock);
	mutex_lock(&port->lock);

	if (port->state != SRC_READY && port->state != SNK_READY) {
		ret = -EAGAIN;
		goto port_unlock;
	}

	if (role == port->vconn_role) {
		ret = 0;
		goto port_unlock;
	}

	port->swap_status = 0;
	port->swap_pending = true;
	reinit_completion(&port->swap_complete);
	tcpm_set_state(port, VCONN_SWAP_SEND, 0);
	mutex_unlock(&port->lock);

	if (!wait_for_completion_timeout(&port->swap_complete,
				msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
		ret = -ETIMEDOUT;
	else
		ret = port->swap_status;

	goto swap_unlock;

port_unlock:
	mutex_unlock(&port->lock);
swap_unlock:
	mutex_unlock(&port->swap_lock);
	return ret;
}

static int tcpm_try_role(const struct typec_capability *cap, int role)
{
	struct tcpm_port *port = typec_cap_to_tcpm(cap);
	struct tcpc_dev	*tcpc = port->tcpc;
	int ret = 0;

	mutex_lock(&port->lock);
	if (tcpc->try_role)
		ret = tcpc->try_role(tcpc, role);
	if (!ret && !tcpc->config->try_role_hw)
		port->try_role = role;
	port->try_src_count = 0;
	port->try_snk_count = 0;
	mutex_unlock(&port->lock);

	return ret;
}

static void tcpm_init(struct tcpm_port *port)
{
	enum typec_cc_status cc1, cc2;

	port->tcpc->init(port->tcpc);

	tcpm_reset_port(port);

	/*
	 * XXX
	 * Should possibly wait for VBUS to settle if it was enabled locally
	 * since tcpm_reset_port() will disable VBUS.
	 */
	port->vbus_present = port->tcpc->get_vbus(port->tcpc);
	if (port->vbus_present)
		port->vbus_never_low = true;

	tcpm_set_state(port, tcpm_default_state(port), 0);

	if (port->tcpc->get_cc(port->tcpc, &cc1, &cc2) == 0)
		_tcpm_cc_change(port, cc1, cc2);

	/*
	 * Some adapters need a clean slate at startup, and won't recover
	 * otherwise. So do not try to be fancy and force a clean disconnect.
	 */
	tcpm_set_state(port, PORT_RESET, 0);
}

static int tcpm_port_type_set(const struct typec_capability *cap,
		enum typec_port_type type)
{
	struct tcpm_port *port = typec_cap_to_tcpm(cap);

	mutex_lock(&port->lock);
	if (type == port->port_type)
		goto port_unlock;

	port->port_type = type;

	if (!port->connected)
		tcpm_set_state(port, PORT_RESET, 0);
	else if (type == TYPEC_PORT_UFP) {
		if (!(port->pwr_role == TYPEC_SINK &&
				port->data_role == TYPEC_DEVICE))
			tcpm_set_state(port, PORT_RESET, 0);
	} else if (type == TYPEC_PORT_DFP) {
		if (!(port->pwr_role == TYPEC_SOURCE &&
				port->data_role == TYPEC_HOST))
			tcpm_set_state(port, PORT_RESET, 0);
	}

port_unlock:
	mutex_unlock(&port->lock);
	return 0;
}


void tcpm_tcpc_reset(struct tcpm_port *port)
{
	mutex_lock(&port->lock);
	/* XXX: Maintain PD connection if possible? */
	tcpm_init(port);
	mutex_unlock(&port->lock);
}
EXPORT_SYMBOL_GPL(tcpm_tcpc_reset);

static int tcpm_copy_pdos(u32 *dest_pdo, const u32 *src_pdo,
			  unsigned int nr_pdo)
{
	unsigned int i;

	if (nr_pdo > PDO_MAX_OBJECTS)
		nr_pdo = PDO_MAX_OBJECTS;

	for (i = 0; i < nr_pdo; i++)
		dest_pdo[i] = src_pdo[i];

	return nr_pdo;
}

static int tcpm_copy_vdos(u32 *dest_vdo, const u32 *src_vdo,
			  unsigned int nr_vdo)
{
	unsigned int i;

	if (nr_vdo > VDO_MAX_OBJECTS)
		nr_vdo = VDO_MAX_OBJECTS;

	for (i = 0; i < nr_vdo; i++)
		dest_vdo[i] = src_vdo[i];

	return nr_vdo;
}

void tcpm_update_source_capabilities(struct tcpm_port *port, const u32 *pdo,
				     unsigned int nr_pdo)
{
	mutex_lock(&port->lock);
	port->nr_src_pdo = tcpm_copy_pdos(port->src_pdo, pdo, nr_pdo);
	switch (port->state) {
	case SRC_UNATTACHED:
	case SRC_ATTACH_WAIT:
	case SRC_TRYWAIT:
		tcpm_set_cc(port, tcpm_rp_cc(port));
		break;
	case SRC_SEND_CAPABILITIES:
	case SRC_NEGOTIATE_CAPABILITIES:
	case SRC_READY:
	case SRC_WAIT_NEW_CAPABILITIES:
		tcpm_set_cc(port, tcpm_rp_cc(port));
		tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
		break;
	default:
		break;
	}
	mutex_unlock(&port->lock);
}
EXPORT_SYMBOL_GPL(tcpm_update_source_capabilities);

void tcpm_update_sink_capabilities(struct tcpm_port *port, const u32 *pdo,
				   unsigned int nr_pdo,
				   unsigned int max_snk_mv,
				   unsigned int max_snk_ma,
				   unsigned int max_snk_mw,
				   unsigned int operating_snk_mw)
{
	mutex_lock(&port->lock);
	port->nr_snk_pdo = tcpm_copy_pdos(port->snk_pdo, pdo, nr_pdo);
	port->max_snk_mv = max_snk_mv;
	port->max_snk_ma = max_snk_ma;
	port->max_snk_mw = max_snk_mw;
	port->operating_snk_mw = operating_snk_mw;

	switch (port->state) {
	case SNK_NEGOTIATE_CAPABILITIES:
	case SNK_READY:
	case SNK_TRANSITION_SINK:
	case SNK_TRANSITION_SINK_VBUS:
		tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
		break;
	default:
		break;
	}
	mutex_unlock(&port->lock);
}
EXPORT_SYMBOL_GPL(tcpm_update_sink_capabilities);

struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
{
	struct tcpm_port *port;
	int i, err;

	if (!dev || !tcpc || !tcpc->config ||
	    !tcpc->get_vbus || !tcpc->set_cc || !tcpc->get_cc ||
	    !tcpc->set_polarity || !tcpc->set_vconn || !tcpc->set_vbus ||
	    !tcpc->set_pd_rx || !tcpc->set_roles || !tcpc->pd_transmit)
		return ERR_PTR(-EINVAL);

	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
	if (!port)
		return ERR_PTR(-ENOMEM);

	port->dev = dev;
	port->tcpc = tcpc;

	mutex_init(&port->lock);
	mutex_init(&port->swap_lock);

	port->wq = create_singlethread_workqueue(dev_name(dev));
	if (!port->wq)
		return ERR_PTR(-ENOMEM);
	INIT_DELAYED_WORK(&port->state_machine, tcpm_state_machine_work);
	INIT_DELAYED_WORK(&port->vdm_state_machine, vdm_state_machine_work);
	INIT_WORK(&port->event_work, tcpm_pd_event_handler);

	spin_lock_init(&port->pd_event_lock);

	init_completion(&port->tx_complete);
	init_completion(&port->swap_complete);

	port->nr_src_pdo = tcpm_copy_pdos(port->src_pdo, tcpc->config->src_pdo,
					  tcpc->config->nr_src_pdo);
	port->nr_snk_pdo = tcpm_copy_pdos(port->snk_pdo, tcpc->config->snk_pdo,
					  tcpc->config->nr_snk_pdo);
	port->nr_snk_vdo = tcpm_copy_vdos(port->snk_vdo, tcpc->config->snk_vdo,
					  tcpc->config->nr_snk_vdo);

	port->max_snk_mv = tcpc->config->max_snk_mv;
	port->max_snk_ma = tcpc->config->max_snk_ma;
	port->max_snk_mw = tcpc->config->max_snk_mw;
	port->operating_snk_mw = tcpc->config->operating_snk_mw;
	if (!tcpc->config->try_role_hw)
		port->try_role = tcpc->config->default_role;
	else
		port->try_role = TYPEC_NO_PREFERRED_ROLE;

	port->typec_caps.prefer_role = tcpc->config->default_role;
	port->typec_caps.type = tcpc->config->type;
	port->typec_caps.revision = 0x0120;	/* Type-C spec release 1.2 */
	port->typec_caps.pd_revision = 0x0200;	/* USB-PD spec release 2.0 */
	port->typec_caps.dr_set = tcpm_dr_set;
	port->typec_caps.pr_set = tcpm_pr_set;
	port->typec_caps.vconn_set = tcpm_vconn_set;
	port->typec_caps.try_role = tcpm_try_role;
	port->typec_caps.port_type_set = tcpm_port_type_set;

	port->partner_desc.identity = &port->partner_ident;
	port->port_type = tcpc->config->type;

	/*
	 * TODO:
	 *  - alt_modes, set_alt_mode
	 *  - {debug,audio}_accessory
	 */

	port->typec_port = typec_register_port(port->dev, &port->typec_caps);
	if (!port->typec_port) {
		err = -ENOMEM;
		goto out_destroy_wq;
	}

	if (tcpc->config->alt_modes) {
		struct typec_altmode_desc *paltmode = tcpc->config->alt_modes;

		i = 0;
		while (paltmode->svid && i < ARRAY_SIZE(port->port_altmode)) {
			port->port_altmode[i] =
			  typec_port_register_altmode(port->typec_port,
						      paltmode);
			if (!port->port_altmode[i]) {
				tcpm_log(port,
					 "%s: failed to register port alternate mode 0x%x",
					 dev_name(dev), paltmode->svid);
				break;
			}
			i++;
			paltmode++;
		}
	}

	tcpm_debugfs_init(port);
	mutex_lock(&port->lock);
	tcpm_init(port);
	mutex_unlock(&port->lock);

	tcpm_log(port, "%s: registered", dev_name(dev));
	return port;

out_destroy_wq:
	destroy_workqueue(port->wq);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(tcpm_register_port);

void tcpm_unregister_port(struct tcpm_port *port)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(port->port_altmode); i++)
		typec_unregister_altmode(port->port_altmode[i]);
	typec_unregister_port(port->typec_port);
	tcpm_debugfs_exit(port);
	destroy_workqueue(port->wq);
}
EXPORT_SYMBOL_GPL(tcpm_unregister_port);

MODULE_AUTHOR("Guenter Roeck <groeck@chromium.org>");
MODULE_DESCRIPTION("USB Type-C Port Manager");
MODULE_LICENSE("GPL");