drivers/mfd/cros_ec_i2c.c - kernel/msm-5.4 - Gitiles

 /*
  * ChromeOS EC multi-function device (I2C)
  *
  * Copyright (C) 2012 Google, Inc
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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.
  */

 #include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

 /**
  * 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 inline struct cros_ec_device *to_ec_dev(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);

 	return i2c_get_clientdata(client);
 }

 static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev,
 				struct cros_ec_command *msg)
 {
 	struct i2c_client *client = ec_dev->priv;
 	int ret = -ENOMEM;
 	int i;
 	int packet_len;
 	u8 *out_buf = NULL;
 	u8 *in_buf = NULL;
 	u8 sum;
 	struct i2c_msg i2c_msg[2];
 	struct ec_host_response *ec_response;
 	struct ec_host_request_i2c *ec_request_i2c;
 	struct ec_host_response_i2c *ec_response_i2c;
 	int request_header_size = sizeof(struct ec_host_request_i2c);
 	int response_header_size = sizeof(struct ec_host_response_i2c);

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

 	packet_len = msg->insize + response_header_size;
 	BUG_ON(packet_len > ec_dev->din_size);
 	in_buf = ec_dev->din;
 	i2c_msg[1].len = packet_len;
 	i2c_msg[1].buf = (char *) in_buf;

 	packet_len = msg->outsize + request_header_size;
 	BUG_ON(packet_len > ec_dev->dout_size);
 	out_buf = ec_dev->dout;
 	i2c_msg[0].len = packet_len;
 	i2c_msg[0].buf = (char *) out_buf;

 	/* create request data */
 	ec_request_i2c = (struct ec_host_request_i2c *) out_buf;
 	ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;

 	ec_dev->dout++;
 	ret = cros_ec_prepare_tx(ec_dev, msg);
 	ec_dev->dout--;

 	/* send command to EC and read answer */
 	ret = i2c_transfer(client->adapter, i2c_msg, 2);
 	if (ret < 0) {
 		dev_dbg(ec_dev->dev, "i2c transfer failed: %d\n", ret);
 		goto done;
 	} else if (ret != 2) {
 		dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
 		ret = -EIO;
 		goto done;
 	}

 	ec_response_i2c = (struct ec_host_response_i2c *) in_buf;
 	msg->result = ec_response_i2c->result;
 	ec_response = &ec_response_i2c->ec_response;

 	switch (msg->result) {
 	case EC_RES_SUCCESS:
 		break;
 	case EC_RES_IN_PROGRESS:
 		ret = -EAGAIN;
 		dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
 			msg->command);
 		goto done;

 	default:
 		dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
 			msg->command, msg->result);
 		/*
 		 * When we send 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) {
 			ret = -EPROTONOSUPPORT;
 			goto done;
 		}
 	}

 	if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
 		dev_err(ec_dev->dev,
 			"response of %u bytes too short; not a full header\n",
 			ec_response_i2c->packet_length);
 		ret = -EBADMSG;
 		goto done;
 	}

 	if (msg->insize < ec_response->data_len) {
 		dev_err(ec_dev->dev,
 			"response data size is too large: expected %u, got %u\n",
 			msg->insize,
 			ec_response->data_len);
 		ret = -EMSGSIZE;
 		goto done;
 	}

 	/* copy response packet payload and compute checksum */
 	sum = 0;
 	for (i = 0; i < sizeof(struct ec_host_response); i++)
 		sum += ((u8 *)ec_response)[i];

 	memcpy(msg->data,
 	       in_buf + response_header_size,
 	       ec_response->data_len);
 	for (i = 0; i < ec_response->data_len; i++)
 		sum += msg->data[i];

 	/* All bytes should sum to zero */
 	if (sum) {
 		dev_err(ec_dev->dev, "bad packet checksum\n");
 		ret = -EBADMSG;
 		goto done;
 	}

 	ret = ec_response->data_len;

 done:
 	if (msg->command == EC_CMD_REBOOT_EC)
 		msleep(EC_REBOOT_DELAY_MS);

 	return ret;
 }

 static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
 				struct cros_ec_command *msg)
 {
 	struct i2c_client *client = ec_dev->priv;
 	int ret = -ENOMEM;
 	int i;
 	int len;
 	int packet_len;
 	u8 *out_buf = NULL;
 	u8 *in_buf = NULL;
 	u8 sum;
 	struct i2c_msg i2c_msg[2];

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

 	/*
 	 * allocate larger packet (one byte for checksum, one byte for
 	 * length, and one for result code)
 	 */
 	packet_len = msg->insize + 3;
 	in_buf = kzalloc(packet_len, GFP_KERNEL);
 	if (!in_buf)
 		goto done;
 	i2c_msg[1].len = packet_len;
 	i2c_msg[1].buf = (char *)in_buf;

 	/*
 	 * allocate larger packet (one byte for checksum, one for
 	 * command code, one for length, and one for command version)
 	 */
 	packet_len = msg->outsize + 4;
 	out_buf = kzalloc(packet_len, GFP_KERNEL);
 	if (!out_buf)
 		goto done;
 	i2c_msg[0].len = packet_len;
 	i2c_msg[0].buf = (char *)out_buf;

 	out_buf[0] = EC_CMD_VERSION0 + msg->version;
 	out_buf[1] = msg->command;
 	out_buf[2] = msg->outsize;

 	/* copy message payload and compute checksum */
 	sum = out_buf[0] + out_buf[1] + out_buf[2];
 	for (i = 0; i < msg->outsize; i++) {
 		out_buf[3 + i] = msg->data[i];
 		sum += out_buf[3 + i];
 	}
 	out_buf[3 + msg->outsize] = sum;

 	/* send command to EC and read answer */
 	ret = i2c_transfer(client->adapter, i2c_msg, 2);
 	if (ret < 0) {
 		dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
 		goto done;
 	} else if (ret != 2) {
 		dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
 		ret = -EIO;
 		goto done;
 	}

 	/* check response error code */
 	msg->result = i2c_msg[1].buf[0];
 	ret = cros_ec_check_result(ec_dev, msg);
 	if (ret)
 		goto done;

 	len = in_buf[1];
 	if (len > msg->insize) {
 		dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
 			len, msg->insize);
 		ret = -ENOSPC;
 		goto done;
 	}

 	/* copy response packet payload and compute checksum */
 	sum = in_buf[0] + in_buf[1];
 	for (i = 0; i < len; i++) {
 		msg->data[i] = in_buf[2 + i];
 		sum += in_buf[2 + i];
 	}
 	dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
 		i2c_msg[1].len, in_buf, sum);
 	if (sum != in_buf[2 + len]) {
 		dev_err(ec_dev->dev, "bad packet checksum\n");
 		ret = -EBADMSG;
 		goto done;
 	}

 	ret = len;
 done:
 	kfree(in_buf);
 	kfree(out_buf);
 	if (msg->command == EC_CMD_REBOOT_EC)
 		msleep(EC_REBOOT_DELAY_MS);

 	return ret;
 }

 static int cros_ec_i2c_probe(struct i2c_client *client,
 			     const struct i2c_device_id *dev_id)
 {
 	struct device *dev = &client->dev;
 	struct cros_ec_device *ec_dev = NULL;
 	int err;

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

 	i2c_set_clientdata(client, ec_dev);
 	ec_dev->dev = dev;
 	ec_dev->priv = client;
 	ec_dev->irq = client->irq;
 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
 	ec_dev->phys_name = client->adapter->name;
 	ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
 			   sizeof(struct ec_response_get_protocol_info);
 	ec_dev->dout_size = sizeof(struct ec_host_request_i2c);

 	err = cros_ec_register(ec_dev);
 	if (err) {
 		dev_err(dev, "cannot register EC\n");
 		return err;
 	}

 	return 0;
 }

 static int cros_ec_i2c_remove(struct i2c_client *client)
 {
 	struct cros_ec_device *ec_dev = i2c_get_clientdata(client);

 	cros_ec_remove(ec_dev);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int cros_ec_i2c_suspend(struct device *dev)
 {
 	struct cros_ec_device *ec_dev = to_ec_dev(dev);

 	return cros_ec_suspend(ec_dev);
 }

 static int cros_ec_i2c_resume(struct device *dev)
 {
 	struct cros_ec_device *ec_dev = to_ec_dev(dev);

 	return cros_ec_resume(ec_dev);
 }
 #endif

 static SIMPLE_DEV_PM_OPS(cros_ec_i2c_pm_ops, cros_ec_i2c_suspend,
 			  cros_ec_i2c_resume);

 static const struct i2c_device_id cros_ec_i2c_id[] = {
 	{ "cros-ec-i2c", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);

 static struct i2c_driver cros_ec_driver = {
 	.driver	= {
 		.name	= "cros-ec-i2c",
 		.owner	= THIS_MODULE,
 		.pm	= &cros_ec_i2c_pm_ops,
 	},
 	.probe		= cros_ec_i2c_probe,
 	.remove		= cros_ec_i2c_remove,
 	.id_table	= cros_ec_i2c_id,
 };

 module_i2c_driver(cros_ec_driver);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("ChromeOS EC multi function device");
	/*
	* ChromeOS EC multi-function device (I2C)
	*
	* Copyright (C) 2012 Google, Inc
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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.
	*/

	#include <linux/delay.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/mfd/cros_ec_commands.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

	/**
	* 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 inline struct cros_ec_device to_ec_dev(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);

	return i2c_get_clientdata(client);
	}

	static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg)
	{
	struct i2c_client *client = ec_dev->priv;
	int ret = -ENOMEM;
	int i;
	int packet_len;
	u8 *out_buf = NULL;
	u8 *in_buf = NULL;
	u8 sum;
	struct i2c_msg i2c_msg[2];
	struct ec_host_response *ec_response;
	struct ec_host_request_i2c *ec_request_i2c;
	struct ec_host_response_i2c *ec_response_i2c;
	int request_header_size = sizeof(struct ec_host_request_i2c);
	int response_header_size = sizeof(struct ec_host_response_i2c);

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

	packet_len = msg->insize + response_header_size;
	BUG_ON(packet_len > ec_dev->din_size);
	in_buf = ec_dev->din;
	i2c_msg[1].len = packet_len;
	i2c_msg[1].buf = (char *) in_buf;

	packet_len = msg->outsize + request_header_size;
	BUG_ON(packet_len > ec_dev->dout_size);
	out_buf = ec_dev->dout;
	i2c_msg[0].len = packet_len;
	i2c_msg[0].buf = (char *) out_buf;

	/* create request data */
	ec_request_i2c = (struct ec_host_request_i2c *) out_buf;
	ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;

	ec_dev->dout++;
	ret = cros_ec_prepare_tx(ec_dev, msg);
	ec_dev->dout--;

	/* send command to EC and read answer */
	ret = i2c_transfer(client->adapter, i2c_msg, 2);
	if (ret < 0) {
	dev_dbg(ec_dev->dev, "i2c transfer failed: %d\n", ret);
	goto done;
	} else if (ret != 2) {
	dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
	ret = -EIO;
	goto done;
	}

	ec_response_i2c = (struct ec_host_response_i2c *) in_buf;
	msg->result = ec_response_i2c->result;
	ec_response = &ec_response_i2c->ec_response;

	switch (msg->result) {
	case EC_RES_SUCCESS:
	break;
	case EC_RES_IN_PROGRESS:
	ret = -EAGAIN;
	dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
	msg->command);
	goto done;

	default:
	dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
	msg->command, msg->result);
	/*
	* When we send 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) {
	ret = -EPROTONOSUPPORT;
	goto done;
	}
	}

	if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
	dev_err(ec_dev->dev,
	"response of %u bytes too short; not a full header\n",
	ec_response_i2c->packet_length);
	ret = -EBADMSG;
	goto done;
	}

	if (msg->insize < ec_response->data_len) {
	dev_err(ec_dev->dev,
	"response data size is too large: expected %u, got %u\n",
	msg->insize,
	ec_response->data_len);
	ret = -EMSGSIZE;
	goto done;
	}

	/* copy response packet payload and compute checksum */
	sum = 0;
	for (i = 0; i < sizeof(struct ec_host_response); i++)
	sum += ((u8 *)ec_response)[i];

	memcpy(msg->data,
	in_buf + response_header_size,
	ec_response->data_len);
	for (i = 0; i < ec_response->data_len; i++)
	sum += msg->data[i];

	/* All bytes should sum to zero */
	if (sum) {
	dev_err(ec_dev->dev, "bad packet checksum\n");
	ret = -EBADMSG;
	goto done;
	}

	ret = ec_response->data_len;

	done:
	if (msg->command == EC_CMD_REBOOT_EC)
	msleep(EC_REBOOT_DELAY_MS);

	return ret;
	}

	static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
	struct cros_ec_command *msg)
	{
	struct i2c_client *client = ec_dev->priv;
	int ret = -ENOMEM;
	int i;
	int len;
	int packet_len;
	u8 *out_buf = NULL;
	u8 *in_buf = NULL;
	u8 sum;
	struct i2c_msg i2c_msg[2];

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

	/*
	* allocate larger packet (one byte for checksum, one byte for
	* length, and one for result code)
	*/
	packet_len = msg->insize + 3;
	in_buf = kzalloc(packet_len, GFP_KERNEL);
	if (!in_buf)
	goto done;
	i2c_msg[1].len = packet_len;
	i2c_msg[1].buf = (char *)in_buf;

	/*
	* allocate larger packet (one byte for checksum, one for
	* command code, one for length, and one for command version)
	*/
	packet_len = msg->outsize + 4;
	out_buf = kzalloc(packet_len, GFP_KERNEL);
	if (!out_buf)
	goto done;
	i2c_msg[0].len = packet_len;
	i2c_msg[0].buf = (char *)out_buf;

	out_buf[0] = EC_CMD_VERSION0 + msg->version;
	out_buf[1] = msg->command;
	out_buf[2] = msg->outsize;

	/* copy message payload and compute checksum */
	sum = out_buf[0] + out_buf[1] + out_buf[2];
	for (i = 0; i < msg->outsize; i++) {
	out_buf[3 + i] = msg->data[i];
	sum += out_buf[3 + i];
	}
	out_buf[3 + msg->outsize] = sum;

	/* send command to EC and read answer */
	ret = i2c_transfer(client->adapter, i2c_msg, 2);
	if (ret < 0) {
	dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
	goto done;
	} else if (ret != 2) {
	dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
	ret = -EIO;
	goto done;
	}

	/* check response error code */
	msg->result = i2c_msg[1].buf[0];
	ret = cros_ec_check_result(ec_dev, msg);
	if (ret)
	goto done;

	len = in_buf[1];
	if (len > msg->insize) {
	dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
	len, msg->insize);
	ret = -ENOSPC;
	goto done;
	}

	/* copy response packet payload and compute checksum */
	sum = in_buf[0] + in_buf[1];
	for (i = 0; i < len; i++) {
	msg->data[i] = in_buf[2 + i];
	sum += in_buf[2 + i];
	}
	dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
	i2c_msg[1].len, in_buf, sum);
	if (sum != in_buf[2 + len]) {
	dev_err(ec_dev->dev, "bad packet checksum\n");
	ret = -EBADMSG;
	goto done;
	}

	ret = len;
	done:
	kfree(in_buf);
	kfree(out_buf);
	if (msg->command == EC_CMD_REBOOT_EC)
	msleep(EC_REBOOT_DELAY_MS);

	return ret;
	}

	static int cros_ec_i2c_probe(struct i2c_client *client,
	const struct i2c_device_id *dev_id)
	{
	struct device *dev = &client->dev;
	struct cros_ec_device *ec_dev = NULL;
	int err;

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

	i2c_set_clientdata(client, ec_dev);
	ec_dev->dev = dev;
	ec_dev->priv = client;
	ec_dev->irq = client->irq;
	ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
	ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
	ec_dev->phys_name = client->adapter->name;
	ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
	sizeof(struct ec_response_get_protocol_info);
	ec_dev->dout_size = sizeof(struct ec_host_request_i2c);

	err = cros_ec_register(ec_dev);
	if (err) {
	dev_err(dev, "cannot register EC\n");
	return err;
	}

	return 0;
	}

	static int cros_ec_i2c_remove(struct i2c_client *client)
	{
	struct cros_ec_device *ec_dev = i2c_get_clientdata(client);

	cros_ec_remove(ec_dev);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int cros_ec_i2c_suspend(struct device *dev)
	{
	struct cros_ec_device *ec_dev = to_ec_dev(dev);

	return cros_ec_suspend(ec_dev);
	}

	static int cros_ec_i2c_resume(struct device *dev)
	{
	struct cros_ec_device *ec_dev = to_ec_dev(dev);

	return cros_ec_resume(ec_dev);
	}
	#endif

	static SIMPLE_DEV_PM_OPS(cros_ec_i2c_pm_ops, cros_ec_i2c_suspend,
	cros_ec_i2c_resume);

	static const struct i2c_device_id cros_ec_i2c_id[] = {
	{ "cros-ec-i2c", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);

	static struct i2c_driver cros_ec_driver = {
	.driver = {
	.name = "cros-ec-i2c",
	.owner = THIS_MODULE,
	.pm = &cros_ec_i2c_pm_ops,
	},
	.probe = cros_ec_i2c_probe,
	.remove = cros_ec_i2c_remove,
	.id_table = cros_ec_i2c_id,
	};

	module_i2c_driver(cros_ec_driver);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("ChromeOS EC multi function device");