drivers/bus/mhi/core/mhi_init.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved. */

#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/mhi.h>
#include "mhi_internal.h"

const char * const mhi_log_level_str[MHI_MSG_LVL_MAX] = {
	[MHI_MSG_LVL_VERBOSE] = "Verbose",
	[MHI_MSG_LVL_INFO] = "Info",
	[MHI_MSG_LVL_ERROR] = "Error",
	[MHI_MSG_LVL_CRITICAL] = "Critical",
	[MHI_MSG_LVL_MASK_ALL] = "Mask all",
};

const char * const mhi_ee_str[MHI_EE_MAX] = {
	[MHI_EE_PBL] = "PBL",
	[MHI_EE_SBL] = "SBL",
	[MHI_EE_AMSS] = "AMSS",
	[MHI_EE_RDDM] = "RDDM",
	[MHI_EE_WFW] = "WFW",
	[MHI_EE_PTHRU] = "PASS THRU",
	[MHI_EE_EDL] = "EDL",
	[MHI_EE_DISABLE_TRANSITION] = "DISABLE",
	[MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
};
EXPORT_SYMBOL_GPL(mhi_ee_str);

const char * const mhi_state_tran_str[MHI_ST_TRANSITION_MAX] = {
	[MHI_ST_TRANSITION_PBL] = "PBL",
	[MHI_ST_TRANSITION_READY] = "READY",
	[MHI_ST_TRANSITION_SBL] = "SBL",
	[MHI_ST_TRANSITION_MISSION_MODE] = "MISSION MODE",
	[MHI_ST_TRANSITION_DISABLE] = "DISABLE",
};

const char * const mhi_state_str[MHI_STATE_MAX] = {
	[MHI_STATE_RESET] = "RESET",
	[MHI_STATE_READY] = "READY",
	[MHI_STATE_M0] = "M0",
	[MHI_STATE_M1] = "M1",
	[MHI_STATE_M2] = "M2",
	[MHI_STATE_M3] = "M3",
	[MHI_STATE_M3_FAST] = "M3_FAST",
	[MHI_STATE_BHI] = "BHI",
	[MHI_STATE_SYS_ERR] = "SYS_ERR",
};

static const char * const mhi_pm_state_str[] = {
	[MHI_PM_BIT_DISABLE] = "DISABLE",
	[MHI_PM_BIT_POR] = "POR",
	[MHI_PM_BIT_M0] = "M0",
	[MHI_PM_BIT_M2] = "M2",
	[MHI_PM_BIT_M3_ENTER] = "M?->M3",
	[MHI_PM_BIT_M3] = "M3",
	[MHI_PM_BIT_M3_EXIT] = "M3->M0",
	[MHI_PM_BIT_FW_DL_ERR] = "FW DL Error",
	[MHI_PM_BIT_DEVICE_ERR_DETECT] = "Device Error Detect",
	[MHI_PM_BIT_SYS_ERR_DETECT] = "SYS_ERR Detect",
	[MHI_PM_BIT_SYS_ERR_PROCESS] = "SYS_ERR Process",
	[MHI_PM_BIT_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
	[MHI_PM_BIT_LD_ERR_FATAL_DETECT] = "LD or Error Fatal Detect",
	[MHI_PM_BIT_SHUTDOWN_NO_ACCESS] = "SHUTDOWN No Access",
};

struct mhi_bus mhi_bus;

struct mhi_controller *find_mhi_controller_by_name(const char *name)
{
	struct mhi_controller *mhi_cntrl, *tmp_cntrl;

	list_for_each_entry_safe(mhi_cntrl, tmp_cntrl, &mhi_bus.controller_list,
				 node) {
		if (mhi_cntrl->name && (!strcmp(name, mhi_cntrl->name)))
			return mhi_cntrl;
	}

	return NULL;
}

const char *to_mhi_pm_state_str(enum MHI_PM_STATE state)
{
	int index = find_last_bit((unsigned long *)&state, 32);

	if (index >= ARRAY_SIZE(mhi_pm_state_str))
		return "Invalid State";

	return mhi_pm_state_str[index];
}

void mhi_time_async_cb(struct mhi_device *mhi_dev, u32 sequence,
		       u64 local_time, u64 remote_time)
{
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;

	MHI_LOG("Time response: seq:%llx local: %llu remote: %llu (ticks)\n",
		sequence, local_time, remote_time);
}

void mhi_time_us_async_cb(struct mhi_device *mhi_dev, u32 sequence,
			  u64 local_time, u64 remote_time)
{
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;

	MHI_LOG("Time response: seq:%llx local: %llu remote: %llu (us)\n",
		sequence, LOCAL_TICKS_TO_US(local_time),
		REMOTE_TICKS_TO_US(remote_time));
}

static ssize_t time_show(struct device *dev,
			 struct device_attribute *attr,
			 char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	u64 t_host, t_device;
	int ret;

	ret = mhi_get_remote_time_sync(mhi_dev, &t_host, &t_device);
	if (ret) {
		MHI_ERR("Failed to obtain time, ret:%d\n", ret);
		return scnprintf(buf, PAGE_SIZE,
				 "Request failed or feature unsupported\n");
	}

	return scnprintf(buf, PAGE_SIZE, "local: %llu remote: %llu (ticks)\n",
			 t_host, t_device);
}
static DEVICE_ATTR_RO(time);

static ssize_t time_us_show(struct device *dev,
			    struct device_attribute *attr,
			    char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	u64 t_host, t_device;
	int ret;

	ret = mhi_get_remote_time_sync(mhi_dev, &t_host, &t_device);
	if (ret) {
		MHI_ERR("Failed to obtain time, ret:%d\n", ret);
		return scnprintf(buf, PAGE_SIZE,
				 "Request failed or feature unsupported\n");
	}

	return scnprintf(buf, PAGE_SIZE, "local: %llu remote: %llu (us)\n",
			 LOCAL_TICKS_TO_US(t_host),
			 REMOTE_TICKS_TO_US(t_device));
}
static DEVICE_ATTR_RO(time_us);

static ssize_t time_async_show(struct device *dev,
			       struct device_attribute *attr,
			       char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	u32 seq = prandom_u32();
	int ret;

	if (!seq)
		seq = 1;

	ret = mhi_get_remote_time(mhi_dev, seq, &mhi_time_async_cb);
	if (ret) {
		MHI_ERR("Failed to request time, seq:%llx, ret:%d\n", seq, ret);
		return scnprintf(buf, PAGE_SIZE,
				 "Request failed or feature unsupported\n");
	}

	return scnprintf(buf, PAGE_SIZE,
			 "Requested time asynchronously with seq:%llx\n", seq);
}
static DEVICE_ATTR_RO(time_async);

static ssize_t time_us_async_show(struct device *dev,
				  struct device_attribute *attr,
				  char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	u32 seq = prandom_u32();
	int ret;

	if (!seq)
		seq = 1;

	ret = mhi_get_remote_time(mhi_dev, seq, &mhi_time_us_async_cb);
	if (ret) {
		MHI_ERR("Failed to request time, seq:%llx, ret:%d\n", seq, ret);
		return scnprintf(buf, PAGE_SIZE,
				 "Request failed or feature unsupported\n");
	}

	return scnprintf(buf, PAGE_SIZE,
			 "Requested time asynchronously with seq:%llx\n", seq);
}
static DEVICE_ATTR_RO(time_us_async);

static struct attribute *mhi_tsync_attrs[] = {
	&dev_attr_time.attr,
	&dev_attr_time_us.attr,
	&dev_attr_time_async.attr,
	&dev_attr_time_us_async.attr,
	NULL,
};

static const struct attribute_group mhi_tsync_group = {
	.attrs = mhi_tsync_attrs,
};

static ssize_t log_level_show(struct device *dev,
			      struct device_attribute *attr,
			      char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;

	return snprintf(buf, PAGE_SIZE, "%s\n",
			TO_MHI_LOG_LEVEL_STR(mhi_cntrl->log_lvl));
}

static ssize_t log_level_store(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf,
			       size_t count)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	enum MHI_DEBUG_LEVEL log_level;

	if (kstrtou32(buf, 0, &log_level) < 0)
		return -EINVAL;

	mhi_cntrl->log_lvl = log_level;

	MHI_LOG("IPC log level changed to: %s\n",
		TO_MHI_LOG_LEVEL_STR(log_level));

	return count;
}
static DEVICE_ATTR_RW(log_level);

static ssize_t bus_vote_show(struct device *dev,
			     struct device_attribute *attr,
			     char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);

	return snprintf(buf, PAGE_SIZE, "%d\n",
			atomic_read(&mhi_dev->bus_vote));
}

static ssize_t bus_vote_store(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf,
			      size_t count)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	int ret = -EINVAL;

	if (sysfs_streq(buf, "get")) {
		ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_BUS);
	} else if (sysfs_streq(buf, "put")) {
		mhi_device_put(mhi_dev, MHI_VOTE_BUS);
		ret = 0;
	}

	return ret ? ret : count;
}
static DEVICE_ATTR_RW(bus_vote);

static ssize_t device_vote_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);

	return snprintf(buf, PAGE_SIZE, "%d\n",
			atomic_read(&mhi_dev->dev_vote));
}

static ssize_t device_vote_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf,
				 size_t count)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	int ret = -EINVAL;

	if (sysfs_streq(buf, "get")) {
		ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
	} else if (sysfs_streq(buf, "put")) {
		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
		ret = 0;
	}

	return ret ? ret : count;
}
static DEVICE_ATTR_RW(device_vote);

static struct attribute *mhi_sysfs_attrs[] = {
	&dev_attr_log_level.attr,
	&dev_attr_bus_vote.attr,
	&dev_attr_device_vote.attr,
	NULL,
};

static const struct attribute_group mhi_sysfs_group = {
	.attrs = mhi_sysfs_attrs,
};

void mhi_create_sysfs(struct mhi_controller *mhi_cntrl)
{
	sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj, &mhi_sysfs_group);
	if (mhi_cntrl->mhi_tsync)
		sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj,
				   &mhi_tsync_group);
}

void mhi_destroy_sysfs(struct mhi_controller *mhi_cntrl)
{
	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
	struct mhi_timesync *mhi_tsync = mhi_cntrl->mhi_tsync;
	struct tsync_node *tsync, *tmp;

	if (mhi_tsync) {
		mutex_lock(&mhi_cntrl->tsync_mutex);
		sysfs_remove_group(&mhi_cntrl->mhi_dev->dev.kobj,
				   &mhi_tsync_group);

		spin_lock(&mhi_tsync->lock);
		list_for_each_entry_safe(tsync, tmp, &mhi_tsync->head, node) {
			list_del(&tsync->node);
			kfree(tsync);
		}
		spin_unlock(&mhi_tsync->lock);

		kfree(mhi_cntrl->mhi_tsync);
		mhi_cntrl->mhi_tsync = NULL;
		mutex_unlock(&mhi_cntrl->tsync_mutex);
	}

	sysfs_remove_group(&mhi_dev->dev.kobj, &mhi_sysfs_group);

	/* relinquish any pending votes for device */
	while (atomic_read(&mhi_dev->dev_vote))
		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);

	/* remove pending votes for the bus */
	while (atomic_read(&mhi_dev->bus_vote))
		mhi_device_put(mhi_dev, MHI_VOTE_BUS);
}

/* MHI protocol require transfer ring to be aligned to ring length */
static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
				  struct mhi_ring *ring,
				  u64 len)
{
	ring->alloc_size = len + (len - 1);
	ring->pre_aligned = mhi_alloc_coherent(mhi_cntrl, ring->alloc_size,
					       &ring->dma_handle, GFP_KERNEL);
	if (!ring->pre_aligned)
		return -ENOMEM;

	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
	return 0;
}

/* MHI protocol require transfer ring to be aligned to ring length */
static int mhi_alloc_aligned_ring_uncached(
	struct mhi_controller *mhi_cntrl, struct mhi_ring *ring, u64 len)
{
	ring->alloc_size = len + (len - 1);
	ring->pre_aligned = mhi_alloc_uncached(mhi_cntrl, ring->alloc_size,
					       &ring->dma_handle, GFP_KERNEL);
	if (!ring->pre_aligned)
		return -ENOMEM;

	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
	return 0;
}

void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
{
	int i;
	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;

	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		if (!mhi_event->request_irq)
			continue;

		free_irq(mhi_cntrl->irq[mhi_event->msi], mhi_event);
	}

	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
}

int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
{
	int i;
	int ret;
	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;

	/* for BHI INTVEC msi */
	ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handlr,
				   mhi_intvec_threaded_handlr,
				   IRQF_ONESHOT | IRQF_NO_SUSPEND,
				   "mhi", mhi_cntrl);
	if (ret)
		return ret;

	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		if (!mhi_event->request_irq)
			continue;

		ret = request_irq(mhi_cntrl->irq[mhi_event->msi],
				  mhi_msi_handlr, IRQF_SHARED | IRQF_NO_SUSPEND,
				  "mhi", mhi_event);
		if (ret) {
			MHI_CNTRL_ERR("Error requesting irq:%d for ev:%d\n",
					mhi_cntrl->irq[mhi_event->msi], i);
			goto error_request;
		}
	}

	return 0;

error_request:
	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
		if (!mhi_event->request_irq)
			continue;

		free_irq(mhi_cntrl->irq[mhi_event->msi], mhi_event);
	}
	free_irq(mhi_cntrl->irq[0], mhi_cntrl);

	return ret;
}

void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
{
	int i;
	struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
	struct mhi_cmd *mhi_cmd;
	struct mhi_event *mhi_event;
	struct mhi_ring *ring;

	mhi_cmd = mhi_cntrl->mhi_cmd;
	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
		ring = &mhi_cmd->ring;
		mhi_free_coherent(mhi_cntrl, ring->alloc_size,
				  ring->pre_aligned, ring->dma_handle);
		ring->base = NULL;
		ring->iommu_base = 0;
	}

	mhi_free_coherent(mhi_cntrl,
			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);

	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		if (mhi_event->offload_ev)
			continue;

		ring = &mhi_event->ring;
		if (mhi_event->force_uncached)
			mhi_free_uncached(mhi_cntrl, ring->alloc_size,
					  ring->pre_aligned, ring->dma_handle);
		else
			mhi_free_coherent(mhi_cntrl, ring->alloc_size,
				  ring->pre_aligned, ring->dma_handle);
		ring->base = NULL;
		ring->iommu_base = 0;
	}

	mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
			  mhi_ctxt->er_ctxt_addr);

	mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
			  mhi_ctxt->chan_ctxt_addr);

	kfree(mhi_ctxt);
	mhi_cntrl->mhi_ctxt = NULL;
}

static int mhi_init_debugfs_mhi_states_open(struct inode *inode,
					    struct file *fp)
{
	return single_open(fp, mhi_debugfs_mhi_states_show, inode->i_private);
}

static int mhi_init_debugfs_mhi_event_open(struct inode *inode, struct file *fp)
{
	return single_open(fp, mhi_debugfs_mhi_event_show, inode->i_private);
}

static int mhi_init_debugfs_mhi_chan_open(struct inode *inode, struct file *fp)
{
	return single_open(fp, mhi_debugfs_mhi_chan_show, inode->i_private);
}

static int mhi_init_debugfs_mhi_vote_open(struct inode *inode, struct file *fp)
{
	return single_open(fp, mhi_debugfs_mhi_vote_show, inode->i_private);
}

static const struct file_operations debugfs_state_ops = {
	.open = mhi_init_debugfs_mhi_states_open,
	.release = single_release,
	.read = seq_read,
};

static const struct file_operations debugfs_ev_ops = {
	.open = mhi_init_debugfs_mhi_event_open,
	.release = single_release,
	.read = seq_read,
};

static const struct file_operations debugfs_chan_ops = {
	.open = mhi_init_debugfs_mhi_chan_open,
	.release = single_release,
	.read = seq_read,
};

static const struct file_operations debugfs_vote_ops = {
	.open = mhi_init_debugfs_mhi_vote_open,
	.release = single_release,
	.read = seq_read,
};

DEFINE_DEBUGFS_ATTRIBUTE(debugfs_trigger_reset_fops, NULL,
			 mhi_debugfs_trigger_reset, "%llu\n");

void mhi_init_debugfs(struct mhi_controller *mhi_cntrl)
{
	struct dentry *dentry;
	char node[32];

	if (!mhi_cntrl->parent)
		return;

	snprintf(node, sizeof(node), "%04x_%02u:%02u.%02u",
		 mhi_cntrl->dev_id, mhi_cntrl->domain, mhi_cntrl->bus,
		 mhi_cntrl->slot);

	dentry = debugfs_create_dir(node, mhi_cntrl->parent);
	if (IS_ERR_OR_NULL(dentry))
		return;

	debugfs_create_file_unsafe("states", 0444, dentry, mhi_cntrl,
				   &debugfs_state_ops);
	debugfs_create_file_unsafe("events", 0444, dentry, mhi_cntrl,
				   &debugfs_ev_ops);
	debugfs_create_file_unsafe("chan", 0444, dentry, mhi_cntrl,
				   &debugfs_chan_ops);
	debugfs_create_file_unsafe("vote", 0444, dentry, mhi_cntrl,
				   &debugfs_vote_ops);
	debugfs_create_file_unsafe("reset", 0444, dentry, mhi_cntrl,
				   &debugfs_trigger_reset_fops);
	mhi_cntrl->dentry = dentry;
}

void mhi_deinit_debugfs(struct mhi_controller *mhi_cntrl)
{
	debugfs_remove_recursive(mhi_cntrl->dentry);
	mhi_cntrl->dentry = NULL;
}

int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
{
	struct mhi_ctxt *mhi_ctxt;
	struct mhi_chan_ctxt *chan_ctxt;
	struct mhi_event_ctxt *er_ctxt;
	struct mhi_cmd_ctxt *cmd_ctxt;
	struct mhi_chan *mhi_chan;
	struct mhi_event *mhi_event;
	struct mhi_cmd *mhi_cmd;
	int ret = -ENOMEM, i;

	atomic_set(&mhi_cntrl->dev_wake, 0);
	atomic_set(&mhi_cntrl->alloc_size, 0);
	atomic_set(&mhi_cntrl->pending_pkts, 0);

	mhi_ctxt = kzalloc(sizeof(*mhi_ctxt), GFP_KERNEL);
	if (!mhi_ctxt)
		return -ENOMEM;

	/* setup channel ctxt */
	mhi_ctxt->chan_ctxt = mhi_alloc_coherent(mhi_cntrl,
			sizeof(*mhi_ctxt->chan_ctxt) * mhi_cntrl->max_chan,
			&mhi_ctxt->chan_ctxt_addr, GFP_KERNEL);
	if (!mhi_ctxt->chan_ctxt)
		goto error_alloc_chan_ctxt;

	mhi_chan = mhi_cntrl->mhi_chan;
	chan_ctxt = mhi_ctxt->chan_ctxt;
	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
		/* If it's offload channel skip this step */
		if (mhi_chan->offload_ch)
			continue;

		chan_ctxt->chstate = MHI_CH_STATE_DISABLED;
		chan_ctxt->brstmode = mhi_chan->db_cfg.brstmode;
		chan_ctxt->pollcfg = mhi_chan->db_cfg.pollcfg;
		chan_ctxt->chtype = mhi_chan->type;
		chan_ctxt->erindex = mhi_chan->er_index;

		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
		mhi_chan->tre_ring.db_addr = &chan_ctxt->wp;
	}

	/* setup event context */
	mhi_ctxt->er_ctxt = mhi_alloc_coherent(mhi_cntrl,
			sizeof(*mhi_ctxt->er_ctxt) * mhi_cntrl->total_ev_rings,
			&mhi_ctxt->er_ctxt_addr, GFP_KERNEL);
	if (!mhi_ctxt->er_ctxt)
		goto error_alloc_er_ctxt;

	er_ctxt = mhi_ctxt->er_ctxt;
	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
		     mhi_event++) {
		struct mhi_ring *ring = &mhi_event->ring;

		/* it's a satellite ev, we do not touch it */
		if (mhi_event->offload_ev)
			continue;

		er_ctxt->intmodc = 0;
		er_ctxt->intmodt = mhi_event->intmod;
		er_ctxt->ertype = MHI_ER_TYPE_VALID;
		er_ctxt->msivec = mhi_event->msi;
		mhi_event->db_cfg.db_mode = true;

		ring->el_size = sizeof(struct mhi_tre);
		ring->len = ring->el_size * ring->elements;
		if (mhi_event->force_uncached)
			ret = mhi_alloc_aligned_ring_uncached(mhi_cntrl, ring,
				ring->len);
		else
			ret = mhi_alloc_aligned_ring(mhi_cntrl, ring,
				ring->len);
		if (ret)
			goto error_alloc_er;

		ring->rp = ring->wp = ring->base;
		er_ctxt->rbase = ring->iommu_base;
		er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
		er_ctxt->rlen = ring->len;
		ring->ctxt_wp = &er_ctxt->wp;
	}

	/* setup cmd context */
	mhi_ctxt->cmd_ctxt = mhi_alloc_coherent(mhi_cntrl,
				sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
				&mhi_ctxt->cmd_ctxt_addr, GFP_KERNEL);
	if (!mhi_ctxt->cmd_ctxt)
		goto error_alloc_er;

	mhi_cmd = mhi_cntrl->mhi_cmd;
	cmd_ctxt = mhi_ctxt->cmd_ctxt;
	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
		struct mhi_ring *ring = &mhi_cmd->ring;

		ring->el_size = sizeof(struct mhi_tre);
		ring->elements = CMD_EL_PER_RING;
		ring->len = ring->el_size * ring->elements;
		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
		if (ret)
			goto error_alloc_cmd;

		ring->rp = ring->wp = ring->base;
		cmd_ctxt->rbase = ring->iommu_base;
		cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
		cmd_ctxt->rlen = ring->len;
		ring->ctxt_wp = &cmd_ctxt->wp;
	}

	mhi_cntrl->mhi_ctxt = mhi_ctxt;

	return 0;

error_alloc_cmd:
	for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
		struct mhi_ring *ring = &mhi_cmd->ring;

		mhi_free_coherent(mhi_cntrl, ring->alloc_size,
				  ring->pre_aligned, ring->dma_handle);
	}
	mhi_free_coherent(mhi_cntrl,
			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
	i = mhi_cntrl->total_ev_rings;
	mhi_event = mhi_cntrl->mhi_event + i;

error_alloc_er:
	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
		struct mhi_ring *ring = &mhi_event->ring;

		if (mhi_event->offload_ev)
			continue;

		if (mhi_event->force_uncached)
			mhi_free_uncached(mhi_cntrl, ring->alloc_size,
				  ring->pre_aligned, ring->dma_handle);
		else
			mhi_free_coherent(mhi_cntrl, ring->alloc_size,
				  ring->pre_aligned, ring->dma_handle);
	}
	mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
			  mhi_ctxt->er_ctxt_addr);

error_alloc_er_ctxt:
	mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
			  mhi_ctxt->chan_ctxt_addr);

error_alloc_chan_ctxt:
	kfree(mhi_ctxt);

	return ret;
}

/* to be used only if a single event ring with the type is present */
static int mhi_get_er_index(struct mhi_controller *mhi_cntrl,
			    enum mhi_er_data_type type)
{
	int i;
	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;

	/* find event ring for requested type */
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		if (mhi_event->data_type == type)
			return mhi_event->er_index;
	}

	return -ENOENT;
}

static int mhi_init_timesync(struct mhi_controller *mhi_cntrl)
{
	struct mhi_timesync *mhi_tsync;
	u32 time_offset, time_cfg_offset;
	int ret, er_index;

	if (!mhi_cntrl->time_get || !mhi_cntrl->lpm_disable ||
	     !mhi_cntrl->lpm_enable)
		return -EINVAL;

	ret = mhi_get_capability_offset(mhi_cntrl, TIMESYNC_CAP_ID,
					&time_offset);
	if (ret) {
		MHI_CNTRL_LOG("No timesync capability found\n");
		return ret;
	}

	mhi_cntrl->local_timer_freq = arch_timer_get_cntfrq();

	/* register method is supported */
	mhi_tsync = kzalloc(sizeof(*mhi_tsync), GFP_ATOMIC);
	if (!mhi_tsync)
		return -ENOMEM;

	spin_lock_init(&mhi_tsync->lock);
	INIT_LIST_HEAD(&mhi_tsync->head);

	/* save time_offset for obtaining time */
	MHI_CNTRL_LOG("TIME OFFS:0x%x\n", time_offset);
	mhi_tsync->time_reg = mhi_cntrl->regs + time_offset
			      + TIMESYNC_TIME_LOW_OFFSET;

	mhi_cntrl->mhi_tsync = mhi_tsync;

	/* get timesync event ring configuration */
	er_index = mhi_get_er_index(mhi_cntrl, MHI_ER_TSYNC_ELEMENT_TYPE);
	if (er_index < 0) {
		MHI_CNTRL_LOG("Could not find timesync event ring\n");
		return er_index;
	}

	mhi_tsync->db_support = true;

	time_cfg_offset = time_offset + TIMESYNC_CFG_OFFSET;

	/* advertise host support */
	mhi_cntrl->write_reg(mhi_cntrl, mhi_cntrl->regs, time_cfg_offset,
			     MHI_TIMESYNC_DB_SETUP(er_index));

	return 0;
}

int mhi_init_sfr(struct mhi_controller *mhi_cntrl)
{
	struct mhi_sfr_info *sfr_info = mhi_cntrl->mhi_sfr;
	int ret = -EIO;

	if (!sfr_info)
		return ret;

	/* do a clean-up if we reach here post SSR */
	memset(sfr_info->str, 0, sfr_info->len);

	sfr_info->buf_addr = mhi_alloc_coherent(mhi_cntrl, sfr_info->len,
					&sfr_info->dma_addr, GFP_KERNEL);
	if (!sfr_info->buf_addr) {
		MHI_CNTRL_ERR("Failed to allocate memory for sfr\n");
		return -ENOMEM;
	}

	init_completion(&sfr_info->completion);

	ret = mhi_send_cmd(mhi_cntrl, NULL, MHI_CMD_SFR_CFG);
	if (ret) {
		MHI_CNTRL_ERR("Failed to send sfr cfg cmd\n");
		return ret;
	}

	ret = wait_for_completion_timeout(&sfr_info->completion,
			msecs_to_jiffies(mhi_cntrl->timeout_ms));
	if (!ret || sfr_info->ccs != MHI_EV_CC_SUCCESS) {
		MHI_CNTRL_ERR("Failed to get sfr cfg cmd completion\n");
		return -EIO;
	}

	return 0;
}

static int mhi_init_bw_scale(struct mhi_controller *mhi_cntrl)
{
	int ret, er_index;
	u32 bw_cfg_offset;

	/* controller doesn't support dynamic bw switch */
	if (!mhi_cntrl->bw_scale)
		return -ENODEV;

	ret = mhi_get_capability_offset(mhi_cntrl, BW_SCALE_CAP_ID,
					&bw_cfg_offset);
	if (ret)
		return ret;

	/* No ER configured to support BW scale */
	er_index = mhi_get_er_index(mhi_cntrl, MHI_ER_BW_SCALE_ELEMENT_TYPE);
	if (er_index < 0)
		return er_index;

	bw_cfg_offset += BW_SCALE_CFG_OFFSET;

	MHI_CNTRL_LOG("BW_CFG OFFSET:0x%x\n", bw_cfg_offset);

	/* advertise host support */
	mhi_cntrl->write_reg(mhi_cntrl, mhi_cntrl->regs, bw_cfg_offset,
		      MHI_BW_SCALE_SETUP(er_index));

	return 0;
}

int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
{
	u32 val;
	int i, ret;
	struct mhi_chan *mhi_chan;
	struct mhi_event *mhi_event;
	void __iomem *base = mhi_cntrl->regs;
	struct {
		u32 offset;
		u32 mask;
		u32 shift;
		u32 val;
	} reg_info[] = {
		{
			CCABAP_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
		},
		{
			CCABAP_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
		},
		{
			ECABAP_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
		},
		{
			ECABAP_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
		},
		{
			CRCBAP_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
		},
		{
			CRCBAP_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
		},
		{
			MHICFG, MHICFG_NER_MASK, MHICFG_NER_SHIFT,
			mhi_cntrl->total_ev_rings,
		},
		{
			MHICFG, MHICFG_NHWER_MASK, MHICFG_NHWER_SHIFT,
			mhi_cntrl->hw_ev_rings,
		},
		{
			MHICTRLBASE_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->iova_start),
		},
		{
			MHICTRLBASE_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->iova_start),
		},
		{
			MHIDATABASE_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->iova_start),
		},
		{
			MHIDATABASE_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->iova_start),
		},
		{
			MHICTRLLIMIT_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->iova_stop),
		},
		{
			MHICTRLLIMIT_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->iova_stop),
		},
		{
			MHIDATALIMIT_HIGHER, U32_MAX, 0,
			upper_32_bits(mhi_cntrl->iova_stop),
		},
		{
			MHIDATALIMIT_LOWER, U32_MAX, 0,
			lower_32_bits(mhi_cntrl->iova_stop),
		},
		{ 0, 0, 0 }
	};

	MHI_CNTRL_LOG("Initializing MMIO\n");

	/* set up DB register for all the chan rings */
	ret = mhi_read_reg_field(mhi_cntrl, base, CHDBOFF, CHDBOFF_CHDBOFF_MASK,
				 CHDBOFF_CHDBOFF_SHIFT, &val);
	if (ret)
		return -EIO;

	MHI_CNTRL_LOG("CHDBOFF:0x%x\n", val);

	/* setup wake db */
	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
	mhi_cntrl->write_reg(mhi_cntrl, mhi_cntrl->wake_db, 4, 0);
	mhi_cntrl->write_reg(mhi_cntrl, mhi_cntrl->wake_db, 0, 0);
	mhi_cntrl->wake_set = false;

	/* setup special purpose doorbells (timesync, bw scale) */
	mhi_cntrl->tsync_db = base + val + (8 * MHI_TIMESYNC_CHAN_DB);
	mhi_cntrl->bw_scale_db = base + val + (8 * MHI_BW_SCALE_CHAN_DB);

	/* setup channel db addresses */
	mhi_chan = mhi_cntrl->mhi_chan;
	for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
		mhi_chan->tre_ring.db_addr = base + val;

	/* setup event ring db addresses */
	ret = mhi_read_reg_field(mhi_cntrl, base, ERDBOFF, ERDBOFF_ERDBOFF_MASK,
				 ERDBOFF_ERDBOFF_SHIFT, &val);
	if (ret)
		return -EIO;

	MHI_CNTRL_LOG("ERDBOFF:0x%x\n", val);

	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
		if (mhi_event->offload_ev)
			continue;

		mhi_event->ring.db_addr = base + val;
	}

	/* set up DB register for primary CMD rings */
	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;

	MHI_CNTRL_LOG("Programming all MMIO values.\n");
	for (i = 0; reg_info[i].offset; i++)
		mhi_write_reg_field(mhi_cntrl, base, reg_info[i].offset,
				    reg_info[i].mask, reg_info[i].shift,
				    reg_info[i].val);

	/* setup special purpose features such as timesync or bw scaling */
	mhi_init_bw_scale(mhi_cntrl);
	mhi_init_timesync(mhi_cntrl);

	return 0;
}

void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
			  struct mhi_chan *mhi_chan)
{
	struct mhi_ring *buf_ring;
	struct mhi_ring *tre_ring;
	struct mhi_chan_ctxt *chan_ctxt;

	buf_ring = &mhi_chan->buf_ring;
	tre_ring = &mhi_chan->tre_ring;
	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];

	mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
			  tre_ring->pre_aligned, tre_ring->dma_handle);
	vfree(buf_ring->base);

	buf_ring->base = tre_ring->base = NULL;
	chan_ctxt->rbase = 0;
}

int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
		       struct mhi_chan *mhi_chan)
{
	struct mhi_ring *buf_ring;
	struct mhi_ring *tre_ring;
	struct mhi_chan_ctxt *chan_ctxt;
	int ret;

	buf_ring = &mhi_chan->buf_ring;
	tre_ring = &mhi_chan->tre_ring;
	tre_ring->el_size = sizeof(struct mhi_tre);
	tre_ring->len = tre_ring->el_size * tre_ring->elements;
	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
	ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
	if (ret)
		return -ENOMEM;

	buf_ring->el_size = sizeof(struct mhi_buf_info);
	buf_ring->len = buf_ring->el_size * buf_ring->elements;
	buf_ring->base = vzalloc(buf_ring->len);

	if (!buf_ring->base) {
		mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
				  tre_ring->pre_aligned, tre_ring->dma_handle);
		return -ENOMEM;
	}

	chan_ctxt->chstate = MHI_CH_STATE_ENABLED;
	chan_ctxt->rbase = tre_ring->iommu_base;
	chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
	chan_ctxt->rlen = tre_ring->len;
	tre_ring->ctxt_wp = &chan_ctxt->wp;

	tre_ring->rp = tre_ring->wp = tre_ring->base;
	buf_ring->rp = buf_ring->wp = buf_ring->base;
	mhi_chan->db_cfg.db_mode = true;

	/* update to all cores */
	smp_wmb();

	return 0;
}

int mhi_device_configure(struct mhi_device *mhi_dev,
			 enum dma_data_direction dir,
			 struct mhi_buf *cfg_tbl,
			 int elements)
{
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	struct mhi_chan *mhi_chan;
	struct mhi_event_ctxt *er_ctxt;
	struct mhi_chan_ctxt *ch_ctxt;
	int er_index, chan;

	switch (dir) {
	case DMA_TO_DEVICE:
		mhi_chan = mhi_dev->ul_chan;
		break;
	case DMA_BIDIRECTIONAL:
	case DMA_FROM_DEVICE:
	case DMA_NONE:
		mhi_chan = mhi_dev->dl_chan;
		break;
	default:
		return -EINVAL;
	}

	er_index = mhi_chan->er_index;
	chan = mhi_chan->chan;

	for (; elements > 0; elements--, cfg_tbl++) {
		/* update event context array */
		if (!strcmp(cfg_tbl->name, "ECA")) {
			er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[er_index];
			if (sizeof(*er_ctxt) != cfg_tbl->len) {
				MHI_ERR(
					"Invalid ECA size, expected:%zu actual%zu\n",
					sizeof(*er_ctxt), cfg_tbl->len);
				return -EINVAL;
			}
			memcpy((void *)er_ctxt, cfg_tbl->buf, sizeof(*er_ctxt));
			continue;
		}

		/* update channel context array */
		if (!strcmp(cfg_tbl->name, "CCA")) {
			ch_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[chan];
			if (cfg_tbl->len != sizeof(*ch_ctxt)) {
				MHI_ERR(
					"Invalid CCA size, expected:%zu actual:%zu\n",
					sizeof(*ch_ctxt), cfg_tbl->len);
				return -EINVAL;
			}
			memcpy((void *)ch_ctxt, cfg_tbl->buf, sizeof(*ch_ctxt));
			continue;
		}

		return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(mhi_device_configure);

static int of_parse_ev_cfg(struct mhi_controller *mhi_cntrl,
			   struct device_node *of_node)
{
	int i, ret, num = 0;
	struct mhi_event *mhi_event;
	struct device_node *child;

	of_node = of_find_node_by_name(of_node, "mhi_events");
	if (!of_node)
		return -EINVAL;

	for_each_available_child_of_node(of_node, child) {
		if (!strcmp(child->name, "mhi_event"))
			num++;
	}

	if (!num)
		return -EINVAL;

	mhi_cntrl->total_ev_rings = num;
	mhi_cntrl->mhi_event = kcalloc(num, sizeof(*mhi_cntrl->mhi_event),
				       GFP_KERNEL);
	if (!mhi_cntrl->mhi_event)
		return -ENOMEM;

	INIT_LIST_HEAD(&mhi_cntrl->sp_ev_rings);

	/* populate ev ring */
	mhi_event = mhi_cntrl->mhi_event;
	i = 0;
	for_each_available_child_of_node(of_node, child) {
		if (strcmp(child->name, "mhi_event"))
			continue;

		mhi_event->er_index = i++;

		mhi_event->force_uncached = of_property_read_bool(child,
				"mhi,force-uncached");

		ret = of_property_read_u32(child, "mhi,num-elements",
					   (u32 *)&mhi_event->ring.elements);
		if (ret)
			goto error_ev_cfg;

		ret = of_property_read_u32(child, "mhi,intmod",
					   &mhi_event->intmod);
		if (ret)
			goto error_ev_cfg;

		ret = of_property_read_u32(child, "mhi,msi",
					   &mhi_event->msi);
		if (ret)
			goto error_ev_cfg;

		ret = of_property_read_u32(child, "mhi,chan",
					   &mhi_event->chan);
		if (!ret) {
			if (mhi_event->chan >= mhi_cntrl->max_chan)
				goto error_ev_cfg;
			/* this event ring has a dedicated channel */
			mhi_event->mhi_chan =
				&mhi_cntrl->mhi_chan[mhi_event->chan];
		}

		ret = of_property_read_u32(child, "mhi,priority",
					   &mhi_event->priority);
		if (ret)
			goto error_ev_cfg;

		ret = of_property_read_u32(child, "mhi,brstmode",
					   &mhi_event->db_cfg.brstmode);
		if (ret || MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
			goto error_ev_cfg;

		mhi_event->db_cfg.process_db =
			(mhi_event->db_cfg.brstmode == MHI_BRSTMODE_ENABLE) ?
			mhi_db_brstmode : mhi_db_brstmode_disable;

		ret = of_property_read_u32(child, "mhi,data-type",
					   &mhi_event->data_type);
		if (ret)
			mhi_event->data_type = MHI_ER_DATA_ELEMENT_TYPE;

		if (mhi_event->data_type > MHI_ER_DATA_TYPE_MAX)
			goto error_ev_cfg;

		switch (mhi_event->data_type) {
		case MHI_ER_DATA_ELEMENT_TYPE:
			mhi_event->process_event = mhi_process_data_event_ring;
			break;
		case MHI_ER_CTRL_ELEMENT_TYPE:
			mhi_event->process_event = mhi_process_ctrl_ev_ring;
			break;
		case MHI_ER_TSYNC_ELEMENT_TYPE:
			mhi_event->process_event = mhi_process_tsync_ev_ring;
			break;
		case MHI_ER_BW_SCALE_ELEMENT_TYPE:
			mhi_event->process_event = mhi_process_bw_scale_ev_ring;
			break;
		}

		mhi_event->hw_ring = of_property_read_bool(child, "mhi,hw-ev");
		if (mhi_event->hw_ring)
			mhi_cntrl->hw_ev_rings++;
		else
			mhi_cntrl->sw_ev_rings++;
		mhi_event->cl_manage = of_property_read_bool(child,
							"mhi,client-manage");
		mhi_event->offload_ev = of_property_read_bool(child,
							      "mhi,offload");

		/*
		 * special purpose events are handled in a separate kthread
		 * to allow for sleeping functions to be called.
		 */
		if (!mhi_event->offload_ev) {
			if (IS_MHI_ER_PRIORITY_SPECIAL(mhi_event))
				list_add_tail(&mhi_event->node,
						&mhi_cntrl->sp_ev_rings);
			else
				mhi_event->request_irq = true;
		}

		mhi_event++;
	}

	/* we need msi for each event ring + additional one for BHI */
	mhi_cntrl->msi_required = mhi_cntrl->total_ev_rings + 1;

	return 0;

error_ev_cfg:

	kfree(mhi_cntrl->mhi_event);
	return -EINVAL;
}
static int of_parse_ch_cfg(struct mhi_controller *mhi_cntrl,
			   struct device_node *of_node)
{
	int ret;
	struct device_node *child;
	u32 chan;

	ret = of_property_read_u32(of_node, "mhi,max-channels",
				   &mhi_cntrl->max_chan);
	if (ret)
		return ret;

	of_node = of_find_node_by_name(of_node, "mhi_channels");
	if (!of_node)
		return -EINVAL;

	mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
				      sizeof(*mhi_cntrl->mhi_chan));
	if (!mhi_cntrl->mhi_chan)
		return -ENOMEM;

	INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);

	/* populate channel configurations */
	for_each_available_child_of_node(of_node, child) {
		struct mhi_chan *mhi_chan;

		if (strcmp(child->name, "mhi_chan"))
			continue;

		ret = of_property_read_u32(child, "reg", &chan);
		if (ret || chan >= mhi_cntrl->max_chan)
			goto error_chan_cfg;

		mhi_chan = &mhi_cntrl->mhi_chan[chan];

		ret = of_property_read_string(child, "label",
					      &mhi_chan->name);
		if (ret)
			goto error_chan_cfg;

		mhi_chan->chan = chan;

		ret = of_property_read_u32(child, "mhi,num-elements",
					   (u32 *)&mhi_chan->tre_ring.elements);
		if (!ret && !mhi_chan->tre_ring.elements)
			goto error_chan_cfg;

		/*
		 * For some channels, local ring len should be bigger than
		 * transfer ring len due to internal logical channels in device.
		 * So host can queue much more buffers than transfer ring len.
		 * Example, RSC channels should have a larger local channel
		 * than transfer ring length.
		 */
		ret = of_property_read_u32(child, "mhi,local-elements",
					   (u32 *)&mhi_chan->buf_ring.elements);
		if (ret)
			mhi_chan->buf_ring.elements =
				mhi_chan->tre_ring.elements;

		ret = of_property_read_u32(child, "mhi,event-ring",
					   &mhi_chan->er_index);
		if (ret)
			goto error_chan_cfg;

		ret = of_property_read_u32(child, "mhi,chan-dir",
					   &mhi_chan->dir);
		if (ret)
			goto error_chan_cfg;

		/*
		 * For most channels, chtype is identical to channel directions,
		 * if not defined, assign ch direction to chtype
		 */
		ret = of_property_read_u32(child, "mhi,chan-type",
					   &mhi_chan->type);
		if (ret)
			mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;

		ret = of_property_read_u32(child, "mhi,ee", &mhi_chan->ee_mask);
		if (ret)
			goto error_chan_cfg;

		of_property_read_u32(child, "mhi,pollcfg",
				     &mhi_chan->db_cfg.pollcfg);

		ret = of_property_read_u32(child, "mhi,data-type",
					   &mhi_chan->xfer_type);
		if (ret)
			goto error_chan_cfg;

		switch (mhi_chan->xfer_type) {
		case MHI_XFER_BUFFER:
			mhi_chan->gen_tre = mhi_gen_tre;
			mhi_chan->queue_xfer = mhi_queue_buf;
			break;
		case MHI_XFER_SKB:
			mhi_chan->queue_xfer = mhi_queue_skb;
			break;
		case MHI_XFER_SCLIST:
			mhi_chan->gen_tre = mhi_gen_tre;
			mhi_chan->queue_xfer = mhi_queue_sclist;
			break;
		case MHI_XFER_NOP:
			mhi_chan->queue_xfer = mhi_queue_nop;
			break;
		case MHI_XFER_DMA:
		case MHI_XFER_RSC_DMA:
			mhi_chan->queue_xfer = mhi_queue_dma;
			break;
		default:
			goto error_chan_cfg;
		}

		mhi_chan->lpm_notify = of_property_read_bool(child,
							     "mhi,lpm-notify");
		mhi_chan->offload_ch = of_property_read_bool(child,
							"mhi,offload-chan");
		mhi_chan->db_cfg.reset_req = of_property_read_bool(child,
							"mhi,db-mode-switch");
		mhi_chan->pre_alloc = of_property_read_bool(child,
							    "mhi,auto-queue");
		mhi_chan->auto_start = of_property_read_bool(child,
							     "mhi,auto-start");
		mhi_chan->wake_capable = of_property_read_bool(child,
							"mhi,wake-capable");

		if (mhi_chan->pre_alloc &&
		    (mhi_chan->dir != DMA_FROM_DEVICE ||
		     mhi_chan->xfer_type != MHI_XFER_BUFFER))
			goto error_chan_cfg;

		/* bi-dir and dirctionless channels must be a offload chan */
		if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
		     mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch)
			goto error_chan_cfg;

		/* if mhi host allocate the buffers then client cannot queue */
		if (mhi_chan->pre_alloc)
			mhi_chan->queue_xfer = mhi_queue_nop;

		if (!mhi_chan->offload_ch) {
			ret = of_property_read_u32(child, "mhi,doorbell-mode",
						   &mhi_chan->db_cfg.brstmode);
			if (ret ||
			    MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode))
				goto error_chan_cfg;

			mhi_chan->db_cfg.process_db =
				(mhi_chan->db_cfg.brstmode ==
				 MHI_BRSTMODE_ENABLE) ?
				mhi_db_brstmode : mhi_db_brstmode_disable;
		}

		mhi_chan->configured = true;

		if (mhi_chan->lpm_notify)
			list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
	}

	return 0;

error_chan_cfg:
	vfree(mhi_cntrl->mhi_chan);

	return -EINVAL;
}

static int of_parse_dt(struct mhi_controller *mhi_cntrl,
		       struct device_node *of_node)
{
	int ret;
	enum mhi_ee i;
	u32 *ee;
	u32 bhie_offset;

	/* parse MHI channel configuration */
	ret = of_parse_ch_cfg(mhi_cntrl, of_node);
	if (ret)
		return ret;

	/* parse MHI event configuration */
	ret = of_parse_ev_cfg(mhi_cntrl, of_node);
	if (ret)
		goto error_ev_cfg;

	ret = of_property_read_u32(of_node, "mhi,timeout",
				   &mhi_cntrl->timeout_ms);
	if (ret)
		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;

	mhi_cntrl->bounce_buf = of_property_read_bool(of_node, "mhi,use-bb");
	ret = of_property_read_u32(of_node, "mhi,buffer-len",
				   (u32 *)&mhi_cntrl->buffer_len);
	if (ret)
		mhi_cntrl->buffer_len = MHI_MAX_MTU;

	/* by default host allowed to ring DB both M0 and M2 state */
	mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
	if (of_property_read_bool(of_node, "mhi,m2-no-db-access"))
		mhi_cntrl->db_access &= ~MHI_PM_M2;

	/* parse the device ee table */
	for (i = MHI_EE_PBL, ee = mhi_cntrl->ee_table; i < MHI_EE_MAX;
	     i++, ee++) {
		/* setup the default ee before checking for override */
		*ee = i;
		ret = of_property_match_string(of_node, "mhi,ee-names",
					       mhi_ee_str[i]);
		if (ret < 0)
			continue;

		of_property_read_u32_index(of_node, "mhi,ee", ret, ee);
	}

	ret = of_property_read_u32(of_node, "mhi,bhie-offset", &bhie_offset);
	if (!ret)
		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_offset;

	of_property_read_string(of_node, "mhi,name", &mhi_cntrl->name);

	return 0;

error_ev_cfg:
	vfree(mhi_cntrl->mhi_chan);

	return ret;
}

int of_register_mhi_controller(struct mhi_controller *mhi_cntrl)
{
	int ret;
	int i;
	struct mhi_event *mhi_event;
	struct mhi_chan *mhi_chan;
	struct mhi_cmd *mhi_cmd;
	struct mhi_device *mhi_dev;
	struct mhi_sfr_info *sfr_info;
	u32 soc_info;

	if (!mhi_cntrl->of_node)
		return -EINVAL;

	if (!mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put)
		return -EINVAL;

	if (!mhi_cntrl->status_cb || !mhi_cntrl->link_status)
		return -EINVAL;

	ret = of_parse_dt(mhi_cntrl, mhi_cntrl->of_node);
	if (ret)
		return -EINVAL;

	mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
				     sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
	if (!mhi_cntrl->mhi_cmd) {
		ret = -ENOMEM;
		goto error_alloc_cmd;
	}

	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
	mutex_init(&mhi_cntrl->pm_mutex);
	mutex_init(&mhi_cntrl->tsync_mutex);
	rwlock_init(&mhi_cntrl->pm_lock);
	spin_lock_init(&mhi_cntrl->transition_lock);
	spin_lock_init(&mhi_cntrl->wlock);
	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
	init_waitqueue_head(&mhi_cntrl->state_event);

	mhi_cntrl->special_wq = alloc_ordered_workqueue("mhi_special_w",
						WQ_MEM_RECLAIM | WQ_HIGHPRI);
	if (!mhi_cntrl->special_wq)
		goto error_alloc_cmd;

	INIT_WORK(&mhi_cntrl->special_work, mhi_special_purpose_work);

	mhi_cmd = mhi_cntrl->mhi_cmd;
	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
		spin_lock_init(&mhi_cmd->lock);

	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		if (mhi_event->offload_ev)
			continue;

		mhi_event->mhi_cntrl = mhi_cntrl;
		spin_lock_init(&mhi_event->lock);

		if (IS_MHI_ER_PRIORITY_SPECIAL(mhi_event))
			continue;

		if (mhi_event->data_type == MHI_ER_CTRL_ELEMENT_TYPE)
			tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
				     (ulong)mhi_event);
		else
			tasklet_init(&mhi_event->task, mhi_ev_task,
				     (ulong)mhi_event);
	}

	mhi_chan = mhi_cntrl->mhi_chan;
	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
		mutex_init(&mhi_chan->mutex);
		init_completion(&mhi_chan->completion);
		rwlock_init(&mhi_chan->lock);

		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
		mhi_chan->bei = !!(mhi_event->intmod);
	}

	if (mhi_cntrl->bounce_buf) {
		mhi_cntrl->map_single = mhi_map_single_use_bb;
		mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
	} else {
		mhi_cntrl->map_single = mhi_map_single_no_bb;
		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
	}

	mhi_cntrl->write_reg = mhi_write_reg;

	/* read the device info if possible */
	if (mhi_cntrl->regs) {
		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
				   SOC_HW_VERSION_OFFS, &soc_info);
		if (ret)
			goto error_alloc_dev;

		mhi_cntrl->family_number =
			(soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
			SOC_HW_VERSION_FAM_NUM_SHFT;
		mhi_cntrl->device_number =
			(soc_info & SOC_HW_VERSION_DEV_NUM_BMSK) >>
			SOC_HW_VERSION_DEV_NUM_SHFT;
		mhi_cntrl->major_version =
			(soc_info & SOC_HW_VERSION_MAJOR_VER_BMSK) >>
			SOC_HW_VERSION_MAJOR_VER_SHFT;
		mhi_cntrl->minor_version =
			(soc_info & SOC_HW_VERSION_MINOR_VER_BMSK) >>
			SOC_HW_VERSION_MINOR_VER_SHFT;
	}

	/* register controller with mhi_bus */
	mhi_dev = mhi_alloc_device(mhi_cntrl);
	if (!mhi_dev) {
		ret = -ENOMEM;
		goto error_alloc_dev;
	}

	mhi_dev->dev_type = MHI_CONTROLLER_TYPE;
	mhi_dev->chan_name = mhi_cntrl->name;
	mhi_dev->mhi_cntrl = mhi_cntrl;
	dev_set_name(&mhi_dev->dev, "%04x_%02u.%02u.%02u", mhi_dev->dev_id,
		     mhi_dev->domain, mhi_dev->bus, mhi_dev->slot);

	/* init wake source */
	device_init_wakeup(&mhi_dev->dev, true);

	ret = device_add(&mhi_dev->dev);
	if (ret)
		goto error_add_dev;

	mhi_cntrl->mhi_dev = mhi_dev;

	if (mhi_cntrl->sfr_len) {
		sfr_info = kzalloc(sizeof(*sfr_info), GFP_KERNEL);
		if (!sfr_info) {
			ret = -ENOMEM;
			goto error_add_dev;
		}

		sfr_info->str = kzalloc(mhi_cntrl->sfr_len, GFP_KERNEL);
		if (!sfr_info->str) {
			ret = -ENOMEM;
			goto error_alloc_sfr;
		}

		sfr_info->len = mhi_cntrl->sfr_len;
		mhi_cntrl->mhi_sfr = sfr_info;
	}

	mhi_cntrl->parent = debugfs_lookup(mhi_bus_type.name, NULL);
	mhi_cntrl->klog_lvl = MHI_MSG_LVL_ERROR;

	/* adding it to this list only for debug purpose */
	mutex_lock(&mhi_bus.lock);
	list_add_tail(&mhi_cntrl->node, &mhi_bus.controller_list);
	mutex_unlock(&mhi_bus.lock);

	return 0;

error_alloc_sfr:
	kfree(sfr_info);

error_add_dev:
	mhi_dealloc_device(mhi_cntrl, mhi_dev);

error_alloc_dev:
	kfree(mhi_cntrl->mhi_cmd);
	destroy_workqueue(mhi_cntrl->special_wq);

error_alloc_cmd:
	vfree(mhi_cntrl->mhi_chan);
	kfree(mhi_cntrl->mhi_event);

	return ret;
};
EXPORT_SYMBOL(of_register_mhi_controller);

void mhi_unregister_mhi_controller(struct mhi_controller *mhi_cntrl)
{
	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
	struct mhi_sfr_info *sfr_info = mhi_cntrl->mhi_sfr;

	kfree(mhi_cntrl->mhi_cmd);
	kfree(mhi_cntrl->mhi_event);
	vfree(mhi_cntrl->mhi_chan);
	kfree(mhi_cntrl->mhi_tsync);

	if (sfr_info) {
		kfree(sfr_info->str);
		kfree(sfr_info);
	}

	device_del(&mhi_dev->dev);
	put_device(&mhi_dev->dev);

	mutex_lock(&mhi_bus.lock);
	list_del(&mhi_cntrl->node);
	mutex_unlock(&mhi_bus.lock);
}
EXPORT_SYMBOL_GPL(mhi_unregister_mhi_controller);

/* set ptr to control private data */
static inline void mhi_controller_set_devdata(struct mhi_controller *mhi_cntrl,
					 void *priv)
{
	mhi_cntrl->priv_data = priv;
}


/* allocate mhi controller to register */
struct mhi_controller *mhi_alloc_controller(size_t size)
{
	struct mhi_controller *mhi_cntrl;

	mhi_cntrl = kzalloc(size + sizeof(*mhi_cntrl), GFP_KERNEL);

	if (mhi_cntrl && size)
		mhi_controller_set_devdata(mhi_cntrl, mhi_cntrl + 1);

	return mhi_cntrl;
}
EXPORT_SYMBOL(mhi_alloc_controller);

int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
{
	int ret;
	u32 bhie_off;

	mutex_lock(&mhi_cntrl->pm_mutex);

	ret = mhi_init_dev_ctxt(mhi_cntrl);
	if (ret) {
		MHI_CNTRL_ERR("Error with init dev_ctxt\n");
		goto error_dev_ctxt;
	}

	/*
	 * allocate rddm table if specified, this table is for debug purpose
	 * so we'll ignore erros
	 */
	if (mhi_cntrl->rddm_size) {
		mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
				     mhi_cntrl->rddm_size);

		/*
		 * This controller supports rddm, we need to manually clear
		 * BHIE RX registers since por values are undefined.
		 */
		if (!mhi_cntrl->bhie) {
			ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
					   &bhie_off);
			if (ret) {
				MHI_CNTRL_ERR("Error getting bhie offset\n");
				goto bhie_error;
			}

			mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
		}

		memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS, 0,
			  BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS + 4);

		if (mhi_cntrl->rddm_image)
			mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
	}

	mhi_cntrl->pre_init = true;

	mutex_unlock(&mhi_cntrl->pm_mutex);

	return 0;

bhie_error:
	if (mhi_cntrl->rddm_image) {
		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
		mhi_cntrl->rddm_image = NULL;
	}

error_dev_ctxt:
	mutex_unlock(&mhi_cntrl->pm_mutex);

	return ret;
}
EXPORT_SYMBOL(mhi_prepare_for_power_up);

void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
{
	if (mhi_cntrl->fbc_image) {
		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
		mhi_cntrl->fbc_image = NULL;
	}

	if (mhi_cntrl->rddm_image) {
		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
		mhi_cntrl->rddm_image = NULL;
	}

	mhi_deinit_dev_ctxt(mhi_cntrl);
	mhi_cntrl->pre_init = false;
}
EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);

/* match dev to drv */
static int mhi_match(struct device *dev, struct device_driver *drv)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
	const struct mhi_device_id *id;

	/* if controller type there is no client driver associated with it */
	if (mhi_dev->dev_type == MHI_CONTROLLER_TYPE)
		return 0;

	for (id = mhi_drv->id_table; id->chan[0]; id++)
		if (!strcmp(mhi_dev->chan_name, id->chan)) {
			mhi_dev->id = id;
			return 1;
		}

	return 0;
};

static void mhi_release_device(struct device *dev)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);

	if (mhi_dev->ul_chan)
		mhi_dev->ul_chan->mhi_dev = NULL;

	if (mhi_dev->dl_chan)
		mhi_dev->dl_chan->mhi_dev = NULL;

	kfree(mhi_dev);
}

struct bus_type mhi_bus_type = {
	.name = "mhi",
	.dev_name = "mhi",
	.match = mhi_match,
};

static int mhi_driver_probe(struct device *dev)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	struct device_driver *drv = dev->driver;
	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
	struct mhi_event *mhi_event;
	struct mhi_chan *ul_chan = mhi_dev->ul_chan;
	struct mhi_chan *dl_chan = mhi_dev->dl_chan;
	int ret;

	/* bring device out of lpm */
	ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
	if (ret)
		return ret;

	ret = -EINVAL;
	if (ul_chan) {
		/* lpm notification require status_cb */
		if (ul_chan->lpm_notify && !mhi_drv->status_cb)
			goto exit_probe;

		if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
			goto exit_probe;

		ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
		mhi_dev->status_cb = mhi_drv->status_cb;
		if (ul_chan->auto_start) {
			ret = mhi_prepare_channel(mhi_cntrl, ul_chan);
			if (ret)
				goto exit_probe;
		}
	}

	if (dl_chan) {
		if (dl_chan->lpm_notify && !mhi_drv->status_cb)
			goto exit_probe;

		if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
			goto exit_probe;

		mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];

		/*
		 * if this channal event ring manage by client, then
		 * status_cb must be defined so we can send the async
		 * cb whenever there are pending data
		 */
		if (mhi_event->cl_manage && !mhi_drv->status_cb)
			goto exit_probe;

		dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;

		/* ul & dl uses same status cb */
		mhi_dev->status_cb = mhi_drv->status_cb;
	}

	ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
	if (ret)
		goto exit_probe;

	if (dl_chan && dl_chan->auto_start)
		mhi_prepare_channel(mhi_cntrl, dl_chan);

	mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);

	return ret;

exit_probe:
	mhi_unprepare_from_transfer(mhi_dev);

	mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);

	return ret;
}

static int mhi_driver_remove(struct device *dev)
{
	struct mhi_device *mhi_dev = to_mhi_device(dev);
	struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
	struct mhi_chan *mhi_chan;
	enum MHI_CH_STATE ch_state[] = {
		MHI_CH_STATE_DISABLED,
		MHI_CH_STATE_DISABLED
	};
	int dir;

	/* control device has no work to do */
	if (mhi_dev->dev_type == MHI_CONTROLLER_TYPE)
		return 0;

	MHI_LOG("Removing device for chan:%s\n", mhi_dev->chan_name);

	/* reset both channels */
	for (dir = 0; dir < 2; dir++) {
		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;

		if (!mhi_chan)
			continue;

		/* wake all threads waiting for completion */
		write_lock_irq(&mhi_chan->lock);
		mhi_chan->ccs = MHI_EV_CC_INVALID;
		complete_all(&mhi_chan->completion);
		write_unlock_irq(&mhi_chan->lock);

		/* move channel state to disable, no more processing */
		mutex_lock(&mhi_chan->mutex);
		write_lock_irq(&mhi_chan->lock);
		ch_state[dir] = mhi_chan->ch_state;
		mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
		write_unlock_irq(&mhi_chan->lock);

		/* reset the channel */
		if (!mhi_chan->offload_ch)
			mhi_reset_chan(mhi_cntrl, mhi_chan);

		mutex_unlock(&mhi_chan->mutex);
	}

	/* destroy the device */
	mhi_drv->remove(mhi_dev);

	/* de_init channel if it was enabled */
	for (dir = 0; dir < 2; dir++) {
		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;

		if (!mhi_chan)
			continue;

		mutex_lock(&mhi_chan->mutex);

		if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
		    !mhi_chan->offload_ch)
			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);

		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;

		mutex_unlock(&mhi_chan->mutex);
	}

	/* relinquish any pending votes for device */
	while (atomic_read(&mhi_dev->dev_vote))
		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);

	/* remove pending votes for the bus */
	while (atomic_read(&mhi_dev->bus_vote))
		mhi_device_put(mhi_dev, MHI_VOTE_BUS);

	return 0;
}

int mhi_driver_register(struct mhi_driver *mhi_drv)
{
	struct device_driver *driver = &mhi_drv->driver;

	if (!mhi_drv->probe || !mhi_drv->remove)
		return -EINVAL;

	driver->bus = &mhi_bus_type;
	driver->probe = mhi_driver_probe;
	driver->remove = mhi_driver_remove;
	return driver_register(driver);
}
EXPORT_SYMBOL(mhi_driver_register);

void mhi_driver_unregister(struct mhi_driver *mhi_drv)
{
	driver_unregister(&mhi_drv->driver);
}
EXPORT_SYMBOL(mhi_driver_unregister);

struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
{
	struct mhi_device *mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL);
	struct device *dev;

	if (!mhi_dev)
		return NULL;

	dev = &mhi_dev->dev;
	device_initialize(dev);
	dev->bus = &mhi_bus_type;
	dev->release = mhi_release_device;
	dev->parent = mhi_cntrl->dev;
	mhi_dev->mhi_cntrl = mhi_cntrl;
	mhi_dev->dev_id = mhi_cntrl->dev_id;
	mhi_dev->domain = mhi_cntrl->domain;
	mhi_dev->bus = mhi_cntrl->bus;
	mhi_dev->slot = mhi_cntrl->slot;
	mhi_dev->mtu = MHI_MAX_MTU;
	atomic_set(&mhi_dev->dev_vote, 0);
	atomic_set(&mhi_dev->bus_vote, 0);

	return mhi_dev;
}

static int __init mhi_init(void)
{
	int ret;

	mutex_init(&mhi_bus.lock);
	INIT_LIST_HEAD(&mhi_bus.controller_list);

	/* parent directory */
	debugfs_create_dir(mhi_bus_type.name, NULL);

	ret = bus_register(&mhi_bus_type);

	if (!ret)
		mhi_dtr_init();
	return ret;
}
postcore_initcall(mhi_init);

MODULE_LICENSE("GPL v2");
MODULE_ALIAS("MHI_CORE");
MODULE_DESCRIPTION("MHI Host Interface");