drivers/misc/cros_ec_lpc.c - u-boot-mtk - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Chromium OS cros_ec driver - LPC interface
  *
  * Copyright (c) 2012 The Chromium OS Authors.
  */

 /*
  * The Matrix Keyboard Protocol driver handles talking to the keyboard
  * controller chip. Mostly this is for keyboard functions, but some other
  * things have slipped in, so we provide generic services to talk to the
  * KBC.
  */

 #include <common.h>
 #include <dm.h>
 #include <command.h>
 #include <cros_ec.h>
 #include <asm/io.h>

 #ifdef DEBUG_TRACE
 #define debug_trace(fmt, b...)	debug(fmt, ##b)
 #else
 #define debug_trace(fmt, b...)
 #endif

 static int wait_for_sync(struct cros_ec_dev *dev)
 {
 	unsigned long start;

 	start = get_timer(0);
 	while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) {
 		if (get_timer(start) > 1000) {
 			debug("%s: Timeout waiting for CROS_EC sync\n",
 			      __func__);
 			return -1;
 		}
 	}

 	return 0;
 }

 int cros_ec_lpc_packet(struct udevice *udev, int out_bytes, int in_bytes)
 {
 	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
 	uint8_t *d;
 	int i;

 	if (out_bytes > EC_LPC_HOST_PACKET_SIZE)
 		return log_msg_ret("Cannot send that many bytes\n", -E2BIG);

 	if (in_bytes > EC_LPC_HOST_PACKET_SIZE)
 		return log_msg_ret("Cannot receive that many bytes\n", -E2BIG);

 	if (wait_for_sync(dev))
 		return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT);

 	/* Write data */
 	for (i = 0, d = (uint8_t *)dev->dout; i < out_bytes; i++, d++)
 		outb(*d, EC_LPC_ADDR_HOST_PACKET + i);

 	/* Start the command */
 	outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD);

 	if (wait_for_sync(dev))
 		return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT);

 	/* Read back args */
 	for (i = 0, d = dev->din; i < in_bytes; i++, d++)
 		*d = inb(EC_LPC_ADDR_HOST_PACKET + i);

 	return in_bytes;
 }

 int cros_ec_lpc_command(struct udevice *udev, uint8_t cmd, int cmd_version,
 		     const uint8_t *dout, int dout_len,
 		     uint8_t **dinp, int din_len)
 {
 	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
 	const int cmd_addr = EC_LPC_ADDR_HOST_CMD;
 	const int data_addr = EC_LPC_ADDR_HOST_DATA;
 	const int args_addr = EC_LPC_ADDR_HOST_ARGS;
 	const int param_addr = EC_LPC_ADDR_HOST_PARAM;

 	struct ec_lpc_host_args args;
 	uint8_t *d;
 	int csum;
 	int i;

 	if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) {
 		debug("%s: Cannot send %d bytes\n", __func__, dout_len);
 		return -1;
 	}

 	/* Fill in args */
 	args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
 	args.command_version = cmd_version;
 	args.data_size = dout_len;

 	/* Calculate checksum */
 	csum = cmd + args.flags + args.command_version + args.data_size;
 	for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++)
 		csum += *d;

 	args.checksum = (uint8_t)csum;

 	if (wait_for_sync(dev)) {
 		debug("%s: Timeout waiting ready\n", __func__);
 		return -1;
 	}

 	/* Write args */
 	for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
 		outb(*d, args_addr + i);

 	/* Write data, if any */
 	debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version);
 	for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) {
 		outb(*d, param_addr + i);
 		debug_trace("%02x ", *d);
 	}

 	outb(cmd, cmd_addr);
 	debug_trace("\n");

 	if (wait_for_sync(dev)) {
 		debug("%s: Timeout waiting for response\n", __func__);
 		return -1;
 	}

 	/* Check result */
 	i = inb(data_addr);
 	if (i) {
 		debug("%s: CROS_EC result code %d\n", __func__, i);
 		return -i;
 	}

 	/* Read back args */
 	for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
 		*d = inb(args_addr + i);

 	/*
 	 * If EC didn't modify args flags, then somehow we sent a new-style
 	 * command to an old EC, which means it would have read its params
 	 * from the wrong place.
 	 */
 	if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) {
 		debug("%s: CROS_EC protocol mismatch\n", __func__);
 		return -EC_RES_INVALID_RESPONSE;
 	}

 	if (args.data_size > din_len) {
 		debug("%s: CROS_EC returned too much data %d > %d\n",
 		      __func__, args.data_size, din_len);
 		return -EC_RES_INVALID_RESPONSE;
 	}

 	/* Read data, if any */
 	for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) {
 		*d = inb(param_addr + i);
 		debug_trace("%02x ", *d);
 	}
 	debug_trace("\n");

 	/* Verify checksum */
 	csum = cmd + args.flags + args.command_version + args.data_size;
 	for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++)
 		csum += *d;

 	if (args.checksum != (uint8_t)csum) {
 		debug("%s: CROS_EC response has invalid checksum\n", __func__);
 		return -EC_RES_INVALID_CHECKSUM;
 	}
 	*dinp = dev->din;

 	/* Return actual amount of data received */
 	return args.data_size;
 }

 /**
  * Initialize LPC protocol.
  *
  * @param dev		CROS_EC device
  * @param blob		Device tree blob
  * @return 0 if ok, -1 on error
  */
 int cros_ec_lpc_init(struct cros_ec_dev *dev, const void *blob)
 {
 	int byte, i;

 	/* See if we can find an EC at the other end */
 	byte = 0xff;
 	byte &= inb(EC_LPC_ADDR_HOST_CMD);
 	byte &= inb(EC_LPC_ADDR_HOST_DATA);
 	for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++)
 		byte &= inb(EC_LPC_ADDR_HOST_PARAM + i);
 	if (byte == 0xff) {
 		debug("%s: CROS_EC device not found on LPC bus\n",
 			__func__);
 		return -1;
 	}

 	return 0;
 }

 /*
  * Test if LPC command args are supported.
  *
  * The cheapest way to do this is by looking for the memory-mapped
  * flag.  This is faster than sending a new-style 'hello' command and
  * seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag
  * in args when it responds.
  */
 static int cros_ec_lpc_check_version(struct udevice *dev)
 {
 	if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' &&
 			inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1)
 				== 'C' &&
 			(inb(EC_LPC_ADDR_MEMMAP +
 				EC_MEMMAP_HOST_CMD_FLAGS) &
 				EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) {
 		return 0;
 	}

 	printf("%s: ERROR: old EC interface not supported\n", __func__);
 	return -1;
 }

 static int cros_ec_probe(struct udevice *dev)
 {
 	return cros_ec_register(dev);
 }

 static struct dm_cros_ec_ops cros_ec_ops = {
 	.packet = cros_ec_lpc_packet,
 	.command = cros_ec_lpc_command,
 	.check_version = cros_ec_lpc_check_version,
 };

 static const struct udevice_id cros_ec_ids[] = {
 	{ .compatible = "google,cros-ec-lpc" },
 	{ }
 };

 U_BOOT_DRIVER(cros_ec_lpc) = {
 	.name		= "cros_ec_lpc",
 	.id		= UCLASS_CROS_EC,
 	.of_match	= cros_ec_ids,
 	.probe		= cros_ec_probe,
 	.ops		= &cros_ec_ops,
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Chromium OS cros_ec driver - LPC interface
	*
	* Copyright (c) 2012 The Chromium OS Authors.
	*/

	/*
	* The Matrix Keyboard Protocol driver handles talking to the keyboard
	* controller chip. Mostly this is for keyboard functions, but some other
	* things have slipped in, so we provide generic services to talk to the
	* KBC.
	*/

	#include <common.h>
	#include <dm.h>
	#include <command.h>
	#include <cros_ec.h>
	#include <asm/io.h>

	#ifdef DEBUG_TRACE
	#define debug_trace(fmt, b...) debug(fmt, ##b)
	#else
	#define debug_trace(fmt, b...)
	#endif

	static int wait_for_sync(struct cros_ec_dev *dev)
	{
	unsigned long start;

	start = get_timer(0);
	while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) {
	if (get_timer(start) > 1000) {
	debug("%s: Timeout waiting for CROS_EC sync\n",
	__func__);
	return -1;
	}
	}

	return 0;
	}

	int cros_ec_lpc_packet(struct udevice *udev, int out_bytes, int in_bytes)
	{
	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
	uint8_t *d;
	int i;

	if (out_bytes > EC_LPC_HOST_PACKET_SIZE)
	return log_msg_ret("Cannot send that many bytes\n", -E2BIG);

	if (in_bytes > EC_LPC_HOST_PACKET_SIZE)
	return log_msg_ret("Cannot receive that many bytes\n", -E2BIG);

	if (wait_for_sync(dev))
	return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT);

	/* Write data */
	for (i = 0, d = (uint8_t *)dev->dout; i < out_bytes; i++, d++)
	outb(*d, EC_LPC_ADDR_HOST_PACKET + i);

	/* Start the command */
	outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD);

	if (wait_for_sync(dev))
	return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT);

	/* Read back args */
	for (i = 0, d = dev->din; i < in_bytes; i++, d++)
	*d = inb(EC_LPC_ADDR_HOST_PACKET + i);

	return in_bytes;
	}

	int cros_ec_lpc_command(struct udevice *udev, uint8_t cmd, int cmd_version,
	const uint8_t *dout, int dout_len,
	uint8_t **dinp, int din_len)
	{
	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
	const int cmd_addr = EC_LPC_ADDR_HOST_CMD;
	const int data_addr = EC_LPC_ADDR_HOST_DATA;
	const int args_addr = EC_LPC_ADDR_HOST_ARGS;
	const int param_addr = EC_LPC_ADDR_HOST_PARAM;

	struct ec_lpc_host_args args;
	uint8_t *d;
	int csum;
	int i;

	if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) {
	debug("%s: Cannot send %d bytes\n", __func__, dout_len);
	return -1;
	}

	/* Fill in args */
	args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
	args.command_version = cmd_version;
	args.data_size = dout_len;

	/* Calculate checksum */
	csum = cmd + args.flags + args.command_version + args.data_size;
	for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++)
	csum += *d;

	args.checksum = (uint8_t)csum;

	if (wait_for_sync(dev)) {
	debug("%s: Timeout waiting ready\n", __func__);
	return -1;
	}

	/* Write args */
	for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
	outb(*d, args_addr + i);

	/* Write data, if any */
	debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version);
	for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) {
	outb(*d, param_addr + i);
	debug_trace("%02x ", *d);
	}

	outb(cmd, cmd_addr);
	debug_trace("\n");

	if (wait_for_sync(dev)) {
	debug("%s: Timeout waiting for response\n", __func__);
	return -1;
	}

	/* Check result */
	i = inb(data_addr);
	if (i) {
	debug("%s: CROS_EC result code %d\n", __func__, i);
	return -i;
	}

	/* Read back args */
	for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++)
	*d = inb(args_addr + i);

	/*
	* If EC didn't modify args flags, then somehow we sent a new-style
	* command to an old EC, which means it would have read its params
	* from the wrong place.
	*/
	if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) {
	debug("%s: CROS_EC protocol mismatch\n", __func__);
	return -EC_RES_INVALID_RESPONSE;
	}

	if (args.data_size > din_len) {
	debug("%s: CROS_EC returned too much data %d > %d\n",
	__func__, args.data_size, din_len);
	return -EC_RES_INVALID_RESPONSE;
	}

	/* Read data, if any */
	for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) {
	*d = inb(param_addr + i);
	debug_trace("%02x ", *d);
	}
	debug_trace("\n");

	/* Verify checksum */
	csum = cmd + args.flags + args.command_version + args.data_size;
	for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++)
	csum += *d;

	if (args.checksum != (uint8_t)csum) {
	debug("%s: CROS_EC response has invalid checksum\n", __func__);
	return -EC_RES_INVALID_CHECKSUM;
	}
	*dinp = dev->din;

	/* Return actual amount of data received */
	return args.data_size;
	}

	/**
	* Initialize LPC protocol.
	*
	* @param dev CROS_EC device
	* @param blob Device tree blob
	* @return 0 if ok, -1 on error
	*/
	int cros_ec_lpc_init(struct cros_ec_dev dev, const void blob)
	{
	int byte, i;

	/* See if we can find an EC at the other end */
	byte = 0xff;
	byte &= inb(EC_LPC_ADDR_HOST_CMD);
	byte &= inb(EC_LPC_ADDR_HOST_DATA);
	for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++)
	byte &= inb(EC_LPC_ADDR_HOST_PARAM + i);
	if (byte == 0xff) {
	debug("%s: CROS_EC device not found on LPC bus\n",
	__func__);
	return -1;
	}

	return 0;
	}

	/*
	* Test if LPC command args are supported.
	*
	* The cheapest way to do this is by looking for the memory-mapped
	* flag. This is faster than sending a new-style 'hello' command and
	* seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag
	* in args when it responds.
	*/
	static int cros_ec_lpc_check_version(struct udevice *dev)
	{
	if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' &&
	inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1)
	== 'C' &&
	(inb(EC_LPC_ADDR_MEMMAP +
	EC_MEMMAP_HOST_CMD_FLAGS) &
	EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) {
	return 0;
	}

	printf("%s: ERROR: old EC interface not supported\n", __func__);
	return -1;
	}

	static int cros_ec_probe(struct udevice *dev)
	{
	return cros_ec_register(dev);
	}

	static struct dm_cros_ec_ops cros_ec_ops = {
	.packet = cros_ec_lpc_packet,
	.command = cros_ec_lpc_command,
	.check_version = cros_ec_lpc_check_version,
	};

	static const struct udevice_id cros_ec_ids[] = {
	{ .compatible = "google,cros-ec-lpc" },
	{ }
	};

	U_BOOT_DRIVER(cros_ec_lpc) = {
	.name = "cros_ec_lpc",
	.id = UCLASS_CROS_EC,
	.of_match = cros_ec_ids,
	.probe = cros_ec_probe,
	.ops = &cros_ec_ops,
	};