common/port80.c

/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/* Port 80 module for Chrome EC */

#include "common.h"
#include "console.h"
#include "hooks.h"
#include "host_command.h"
#include "port80.h"
#include "task.h"
#include "timer.h"
#include "util.h"

#define CPRINTF(format, args...) cprintf(CC_PORT80, format, ## args)

#define HISTORY_LEN 256
#define PORT80_POLL_PERIOD MSEC

static uint16_t history[HISTORY_LEN];
static int writes;    /* Number of port 80 writes so far */
static int last_boot; /* Last code from previous boot */
static int scroll;
static int print_in_int = 1;
#ifdef HAS_TASK_PORT80
static int task_en;   /* Port 80 task control */
static int task_timeout = -1;
#endif

void port_80_write(int data)
{
	/*
	 * Note that this currently prints from inside the LPC interrupt
	 * itself.  If you're dropping events, turn print_in_int off.
	 */
	if (print_in_int)
		CPRINTF("%c[%T Port 80: 0x%02x]", scroll ? '\n' : '\r', data);

	/* Save current port80 code if system is resetting */
	if (data == PORT_80_EVENT_RESET && writes) {
		int prev = history[(writes-1) % ARRAY_SIZE(history)];

		/* Ignore special event codes */
		if (prev < 0x100)
			last_boot = prev;
	}

	history[writes % ARRAY_SIZE(history)] = data;
	writes++;
}

#ifdef HAS_TASK_PORT80
/*
 * Port80 POST code polling limitation:
 * - POST code 0xFF is ignored.
 * - POST code frequency is greater than 1 msec.
 */
void port80_task(void)
{
	while (1) {
		int data = port_80_read();

		if (data != PORT_80_IGNORE)
			port_80_write(data);

		task_wait_event(task_timeout);
	}
}

static void port_80_task_enable(void)
{
	task_en = 1;
	task_timeout = PORT80_POLL_PERIOD;
	task_wake(TASK_ID_PORT80);
}

static void port_80_task_disable(void)
{
	task_en = 0;
	task_timeout = -1;
}

#ifdef CONFIG_PORT80_TASK_EN

/* Only enable the port80 task when the AP is started, to save power */
DECLARE_HOOK(HOOK_CHIPSET_RESUME, port_80_task_enable, HOOK_PRIO_DEFAULT);
DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, port_80_task_disable, HOOK_PRIO_DEFAULT);

#endif /* PORT80_TASK_EN */
#endif /* HAS_TASK_PORT80 */

/*****************************************************************************/
/* Console commands */

static int command_port80(int argc, char **argv)
{
	int head, tail;
	int printed = 0;
	int i;

	/*
	 * 'port80 scroll' toggles whether port 80 output begins with a newline
	 * (scrolling) or CR (non-scrolling).
	 */
	if (argc > 1) {
		if (!strcasecmp(argv[1], "scroll")) {
			scroll = !scroll;
			ccprintf("scroll %sabled\n", scroll ? "en" : "dis");
			return EC_SUCCESS;
		} else if (!strcasecmp(argv[1], "intprint")) {
			print_in_int = !print_in_int;
			ccprintf("printing in interrupt %sabled\n",
				 print_in_int ? "en" : "dis");
			return EC_SUCCESS;
		} else if (!strcasecmp(argv[1], "flush")) {
			writes = 0;
			return EC_SUCCESS;
#ifdef HAS_TASK_PORT80
		} else if (!strcasecmp(argv[1], "task")) {
			task_en = !task_en;
			ccprintf("task %sabled\n", task_en ? "en" : "dis");
			task_en ? port_80_task_enable() :
				  port_80_task_disable();

			return EC_SUCCESS;
		} else if (!strcasecmp(argv[1], "poll")) {
			i = port_80_read();
			if (i != PORT_80_IGNORE)
				port_80_write(i);
			/* continue on to print the port 80 history */
#endif
		} else {
			return EC_ERROR_PARAM1;
		}
	}

	/*
	 * Print the port 80 writes so far, clipped to the length of our
	 * history buffer.
	 *
	 * Technically, if a port 80 write comes in while we're printing this,
	 * we could print an incorrect history.  Probably not worth the
	 * complexity to work around that.
	 */
	head = writes;
	if (head > ARRAY_SIZE(history))
		tail = head - ARRAY_SIZE(history);
	else
		tail = 0;

	ccputs("Port 80 writes:");
	for (i = tail; i < head; i++) {
		int e = history[i % ARRAY_SIZE(history)];
		switch (e) {
		case PORT_80_EVENT_RESUME:
			ccprintf("\n(S3->S0)");
			printed = 0;
			break;
		case PORT_80_EVENT_RESET:
			ccprintf("\n(RESET)");
			printed = 0;
			break;
		default:
			if (!(printed++ % 20)) {
				ccputs("\n ");
				cflush();
			}
			ccprintf(" %02x", e);
		}
	}
	ccputs(" <--new\n");
	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(port80, command_port80,
			"[scroll | intprint | flush]",
			"Print port80 writes or toggle port80 scrolling",
			NULL);

int port80_last_boot(struct host_cmd_handler_args *args)
{
	struct ec_response_port80_last_boot *r = args->response;

	args->response_size = sizeof(*r);
	r->code = last_boot;

	return EC_RES_SUCCESS;
}

int port80_command_read(struct host_cmd_handler_args *args)
{
	const struct ec_params_port80_read *p = args->params;
	uint32_t offset = p->read_buffer.offset;
	uint32_t entries = p->read_buffer.num_entries;
	int i;
	struct ec_response_port80_read *rsp = args->response;

	if (args->version == 0)
		return port80_last_boot(args);

	if (p->subcmd == EC_PORT80_GET_INFO) {
		rsp->get_info.writes = writes;
		rsp->get_info.history_size = ARRAY_SIZE(history);
		args->response_size = sizeof(rsp->get_info);
		return EC_RES_SUCCESS;
	} else if (p->subcmd == EC_PORT80_READ_BUFFER) {
		/* do not allow bad offset or size */
		if (offset >= ARRAY_SIZE(history) || entries == 0 ||
			entries > args->response_max)
			return EC_RES_INVALID_PARAM;

		for (i = 0; i < entries; i++) {
			uint16_t e = history[(i + offset) %
				ARRAY_SIZE(history)];
			rsp->data.codes[i] = e;
		}

		args->response_size = entries*sizeof(uint16_t);
		return EC_RES_SUCCESS;
	}

	return EC_RES_INVALID_PARAM;
}
DECLARE_HOST_COMMAND(EC_CMD_PORT80_READ,
		port80_command_read,
		EC_VER_MASK(0) | EC_VER_MASK(1));