drivers/misc/cros_ec_i2c.c - platform/external/u-boot - Gitiles

 /*
  * Chromium OS cros_ec driver - I2C interface
  *
  * Copyright (c) 2012 The Chromium OS Authors.
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 /*
  * 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 <i2c.h>
 #include <cros_ec.h>

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

 /**
  * Request format for protocol v3
  * byte 0	0xda (EC_COMMAND_PROTOCOL_3)
  * byte 1-8	struct ec_host_request
  * byte 10-	response data
  */
 struct ec_host_request_i2c {
 	/* Always 0xda to backward compatible with v2 struct */
 	uint8_t  command_protocol;
 	struct ec_host_request ec_request;
 } __packed;

 /*
  * Response format for protocol v3
  * byte 0	result code
  * byte 1	packet_length
  * byte 2-9	struct ec_host_response
  * byte 10-	response data
  */
 struct ec_host_response_i2c {
 	uint8_t result;
 	uint8_t packet_length;
 	struct ec_host_response ec_response;
 } __packed;

 static int cros_ec_i2c_packet(struct udevice *udev, int out_bytes, int in_bytes)
 {
 	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
 	struct dm_i2c_chip *chip = dev_get_parent_platdata(udev);
 	struct ec_host_request_i2c *ec_request_i2c =
 		(struct ec_host_request_i2c *)dev->dout;
 	struct ec_host_response_i2c *ec_response_i2c =
 		(struct ec_host_response_i2c *)dev->din;
 	struct i2c_msg i2c_msg[2];
 	int ret;

 	i2c_msg[0].addr = chip->chip_addr;
 	i2c_msg[0].flags = 0;
 	i2c_msg[1].addr = chip->chip_addr;
 	i2c_msg[1].flags = I2C_M_RD;

 	/* one extra byte, to indicate v3 */
 	i2c_msg[0].len = out_bytes + 1;
 	i2c_msg[0].buf = dev->dout;

 	/* stitch on EC_COMMAND_PROTOCOL_3 */
 	memmove(&ec_request_i2c->ec_request, dev->dout, out_bytes);
 	ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;

 	/* two extra bytes for v3 */
 	i2c_msg[1].len = in_bytes + 2;
 	i2c_msg[1].buf = dev->din;

 	ret = dm_i2c_xfer(udev, &i2c_msg[0], 2);
 	if (ret) {
 		printf("%s: Could not execute transfer: %d\n", __func__, ret);
 		return ret;
 	}

 	/* When we send a v3 request to v2 ec, ec won't recognize the 0xda
 	 * (EC_COMMAND_PROTOCOL_3) and will return with status
 	 * EC_RES_INVALID_COMMAND with zero data length
 	 *
 	 * In case of invalid command for v3 protocol the data length
 	 * will be at least sizeof(struct ec_host_response)
 	 */
 	if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&
 	    ec_response_i2c->packet_length == 0)
 		return -EPROTONOSUPPORT;

 	if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
 		printf("%s: response of %u bytes too short; not a full hdr\n",
 		       __func__, ec_response_i2c->packet_length);
 		return -EBADMSG;
 	}


 	/* drop result and packet_len */
 	memmove(dev->din, &ec_response_i2c->ec_response, in_bytes);

 	return in_bytes;
 }

 static int cros_ec_i2c_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);
 	struct dm_i2c_chip *chip = dev_get_parent_platdata(udev);
 	struct i2c_msg i2c_msg[2];
 	/* version8, cmd8, arglen8, out8[dout_len], csum8 */
 	int out_bytes = dout_len + 4;
 	/* response8, arglen8, in8[din_len], checksum8 */
 	int in_bytes = din_len + 3;
 	uint8_t *ptr;
 	/* Receive input data, so that args will be dword aligned */
 	uint8_t *in_ptr;
 	int len, csum, ret;

 	/*
 	 * Sanity-check I/O sizes given transaction overhead in internal
 	 * buffers.
 	 */
 	if (out_bytes > sizeof(dev->dout)) {
 		debug("%s: Cannot send %d bytes\n", __func__, dout_len);
 		return -1;
 	}
 	if (in_bytes > sizeof(dev->din)) {
 		debug("%s: Cannot receive %d bytes\n", __func__, din_len);
 		return -1;
 	}
 	assert(dout_len >= 0);
 	assert(dinp);

 	i2c_msg[0].addr = chip->chip_addr;
 	i2c_msg[0].len = out_bytes;
 	i2c_msg[0].buf = dev->dout;
 	i2c_msg[0].flags = 0;

 	/*
 	 * Copy command and data into output buffer so we can do a single I2C
 	 * burst transaction.
 	 */
 	ptr = dev->dout;

 	/*
 	 * in_ptr starts of pointing to a dword-aligned input data buffer.
 	 * We decrement it back by the number of header bytes we expect to
 	 * receive, so that the first parameter of the resulting input data
 	 * will be dword aligned.
 	 */
 	in_ptr = dev->din + sizeof(int64_t);

 	if (dev->protocol_version != 2) {
 		/* Something we don't support */
 		debug("%s: Protocol version %d unsupported\n",
 		      __func__, dev->protocol_version);
 		return -1;
 	}

 	*ptr++ = EC_CMD_VERSION0 + cmd_version;
 	*ptr++ = cmd;
 	*ptr++ = dout_len;
 	in_ptr -= 2;	/* Expect status, length bytes */

 	memcpy(ptr, dout, dout_len);
 	ptr += dout_len;

 	*ptr++ = (uint8_t)
 		cros_ec_calc_checksum(dev->dout, dout_len + 3);

 	i2c_msg[1].addr = chip->chip_addr;
 	i2c_msg[1].len = in_bytes;
 	i2c_msg[1].buf = in_ptr;
 	i2c_msg[1].flags = I2C_M_RD;

 	/* Send output data */
 	cros_ec_dump_data("out", -1, dev->dout, out_bytes);

 	ret = dm_i2c_xfer(udev, &i2c_msg[0], 2);
 	if (ret) {
 		debug("%s: Could not execute transfer to %s\n", __func__,
 		      udev->name);
 		ret = -1;
 	}

 	if (*in_ptr != EC_RES_SUCCESS) {
 		debug("%s: Received bad result code %d\n", __func__, *in_ptr);
 		return -(int)*in_ptr;
 	}

 	len = in_ptr[1];
 	if (len + 3 > sizeof(dev->din)) {
 		debug("%s: Received length %#02x too large\n",
 		      __func__, len);
 		return -1;
 	}
 	csum = cros_ec_calc_checksum(in_ptr, 2 + len);
 	if (csum != in_ptr[2 + len]) {
 		debug("%s: Invalid checksum rx %#02x, calced %#02x\n",
 		      __func__, in_ptr[2 + din_len], csum);
 		return -1;
 	}
 	din_len = min(din_len, len);
 	cros_ec_dump_data("in", -1, in_ptr, din_len + 3);

 	/* Return pointer to dword-aligned input data, if any */
 	*dinp = dev->din + sizeof(int64_t);

 	return din_len;
 }

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

 static struct dm_cros_ec_ops cros_ec_ops = {
 	.command = cros_ec_i2c_command,
 	.packet = cros_ec_i2c_packet,
 };

 static const struct udevice_id cros_ec_ids[] = {
 	{ .compatible = "google,cros-ec-i2c" },
 	{ }
 };

 U_BOOT_DRIVER(cros_ec_i2c) = {
 	.name		= "cros_ec_i2c",
 	.id		= UCLASS_CROS_EC,
 	.of_match	= cros_ec_ids,
 	.probe		= cros_ec_probe,
 	.ops		= &cros_ec_ops,
 };
	/*
	* Chromium OS cros_ec driver - I2C interface
	*
	* Copyright (c) 2012 The Chromium OS Authors.
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	/*
	* 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 <i2c.h>
	#include <cros_ec.h>

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

	/**
	* Request format for protocol v3
	* byte 0 0xda (EC_COMMAND_PROTOCOL_3)
	* byte 1-8 struct ec_host_request
	* byte 10- response data
	*/
	struct ec_host_request_i2c {
	/* Always 0xda to backward compatible with v2 struct */
	uint8_t command_protocol;
	struct ec_host_request ec_request;
	} __packed;

	/*
	* Response format for protocol v3
	* byte 0 result code
	* byte 1 packet_length
	* byte 2-9 struct ec_host_response
	* byte 10- response data
	*/
	struct ec_host_response_i2c {
	uint8_t result;
	uint8_t packet_length;
	struct ec_host_response ec_response;
	} __packed;

	static int cros_ec_i2c_packet(struct udevice *udev, int out_bytes, int in_bytes)
	{
	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
	struct dm_i2c_chip *chip = dev_get_parent_platdata(udev);
	struct ec_host_request_i2c *ec_request_i2c =
	(struct ec_host_request_i2c *)dev->dout;
	struct ec_host_response_i2c *ec_response_i2c =
	(struct ec_host_response_i2c *)dev->din;
	struct i2c_msg i2c_msg[2];
	int ret;

	i2c_msg[0].addr = chip->chip_addr;
	i2c_msg[0].flags = 0;
	i2c_msg[1].addr = chip->chip_addr;
	i2c_msg[1].flags = I2C_M_RD;

	/* one extra byte, to indicate v3 */
	i2c_msg[0].len = out_bytes + 1;
	i2c_msg[0].buf = dev->dout;

	/* stitch on EC_COMMAND_PROTOCOL_3 */
	memmove(&ec_request_i2c->ec_request, dev->dout, out_bytes);
	ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;

	/* two extra bytes for v3 */
	i2c_msg[1].len = in_bytes + 2;
	i2c_msg[1].buf = dev->din;

	ret = dm_i2c_xfer(udev, &i2c_msg[0], 2);
	if (ret) {
	printf("%s: Could not execute transfer: %d\n", __func__, ret);
	return ret;
	}

	/* When we send a v3 request to v2 ec, ec won't recognize the 0xda
	* (EC_COMMAND_PROTOCOL_3) and will return with status
	* EC_RES_INVALID_COMMAND with zero data length
	*
	* In case of invalid command for v3 protocol the data length
	* will be at least sizeof(struct ec_host_response)
	*/
	if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&
	ec_response_i2c->packet_length == 0)
	return -EPROTONOSUPPORT;

	if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
	printf("%s: response of %u bytes too short; not a full hdr\n",
	__func__, ec_response_i2c->packet_length);
	return -EBADMSG;
	}


	/* drop result and packet_len */
	memmove(dev->din, &ec_response_i2c->ec_response, in_bytes);

	return in_bytes;
	}

	static int cros_ec_i2c_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);
	struct dm_i2c_chip *chip = dev_get_parent_platdata(udev);
	struct i2c_msg i2c_msg[2];
	/* version8, cmd8, arglen8, out8[dout_len], csum8 */
	int out_bytes = dout_len + 4;
	/* response8, arglen8, in8[din_len], checksum8 */
	int in_bytes = din_len + 3;
	uint8_t *ptr;
	/* Receive input data, so that args will be dword aligned */
	uint8_t *in_ptr;
	int len, csum, ret;

	/*
	* Sanity-check I/O sizes given transaction overhead in internal
	* buffers.
	*/
	if (out_bytes > sizeof(dev->dout)) {
	debug("%s: Cannot send %d bytes\n", __func__, dout_len);
	return -1;
	}
	if (in_bytes > sizeof(dev->din)) {
	debug("%s: Cannot receive %d bytes\n", __func__, din_len);
	return -1;
	}
	assert(dout_len >= 0);
	assert(dinp);

	i2c_msg[0].addr = chip->chip_addr;
	i2c_msg[0].len = out_bytes;
	i2c_msg[0].buf = dev->dout;
	i2c_msg[0].flags = 0;

	/*
	* Copy command and data into output buffer so we can do a single I2C
	* burst transaction.
	*/
	ptr = dev->dout;

	/*
	* in_ptr starts of pointing to a dword-aligned input data buffer.
	* We decrement it back by the number of header bytes we expect to
	* receive, so that the first parameter of the resulting input data
	* will be dword aligned.
	*/
	in_ptr = dev->din + sizeof(int64_t);

	if (dev->protocol_version != 2) {
	/* Something we don't support */
	debug("%s: Protocol version %d unsupported\n",
	__func__, dev->protocol_version);
	return -1;
	}

	*ptr++ = EC_CMD_VERSION0 + cmd_version;
	*ptr++ = cmd;
	*ptr++ = dout_len;
	in_ptr -= 2; /* Expect status, length bytes */

	memcpy(ptr, dout, dout_len);
	ptr += dout_len;

	*ptr++ = (uint8_t)
	cros_ec_calc_checksum(dev->dout, dout_len + 3);

	i2c_msg[1].addr = chip->chip_addr;
	i2c_msg[1].len = in_bytes;
	i2c_msg[1].buf = in_ptr;
	i2c_msg[1].flags = I2C_M_RD;

	/* Send output data */
	cros_ec_dump_data("out", -1, dev->dout, out_bytes);

	ret = dm_i2c_xfer(udev, &i2c_msg[0], 2);
	if (ret) {
	debug("%s: Could not execute transfer to %s\n", __func__,
	udev->name);
	ret = -1;
	}

	if (*in_ptr != EC_RES_SUCCESS) {
	debug("%s: Received bad result code %d\n", __func__, *in_ptr);
	return -(int)*in_ptr;
	}

	len = in_ptr[1];
	if (len + 3 > sizeof(dev->din)) {
	debug("%s: Received length %#02x too large\n",
	__func__, len);
	return -1;
	}
	csum = cros_ec_calc_checksum(in_ptr, 2 + len);
	if (csum != in_ptr[2 + len]) {
	debug("%s: Invalid checksum rx %#02x, calced %#02x\n",
	__func__, in_ptr[2 + din_len], csum);
	return -1;
	}
	din_len = min(din_len, len);
	cros_ec_dump_data("in", -1, in_ptr, din_len + 3);

	/* Return pointer to dword-aligned input data, if any */
	*dinp = dev->din + sizeof(int64_t);

	return din_len;
	}

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

	static struct dm_cros_ec_ops cros_ec_ops = {
	.command = cros_ec_i2c_command,
	.packet = cros_ec_i2c_packet,
	};

	static const struct udevice_id cros_ec_ids[] = {
	{ .compatible = "google,cros-ec-i2c" },
	{ }
	};

	U_BOOT_DRIVER(cros_ec_i2c) = {
	.name = "cros_ec_i2c",
	.id = UCLASS_CROS_EC,
	.of_match = cros_ec_ids,
	.probe = cros_ec_probe,
	.ops = &cros_ec_ops,
	};