[linux-2.6-block.git] / drivers / mfd / cros_ec_i2c.c

/*
 * 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/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>

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_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);
	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 = NULL;
	ec_dev->ec_name = client->name;
	ec_dev->phys_name = client->adapter->name;
	ec_dev->din_size = sizeof(struct ec_host_response) +
			   sizeof(struct ec_response_get_protocol_info);
	ec_dev->dout_size = sizeof(struct ec_host_request);

	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");
Commit	Line	Data
89969009 SG	1	/*
	2	* ChromeOS EC multi-function device (I2C)
	3	*
	4	* Copyright (C) 2012 Google, Inc
	5	*
	6	* This software is licensed under the terms of the GNU General Public
	7	* License version 2, as published by the Free Software Foundation, and
	8	* may be copied, distributed, and modified under those terms.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/i2c.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/mfd/cros_ec.h>
	21	#include <linux/mfd/cros_ec_commands.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/slab.h>
	24
	25	static inline struct cros_ec_device to_ec_dev(struct device dev)
	26	{
	27	struct i2c_client *client = to_i2c_client(dev);
	28
	29	return i2c_get_clientdata(client);
	30	}
	31
7e6cb5b4	32	static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
5d4773e2	33	struct cros_ec_command *msg)
89969009 SG	34	{
	35	struct i2c_client *client = ec_dev->priv;
	36	int ret = -ENOMEM;
	37	int i;
d6c15ed2	38	int len;
89969009 SG	39	int packet_len;
	40	u8 *out_buf = NULL;
	41	u8 *in_buf = NULL;
	42	u8 sum;
	43	struct i2c_msg i2c_msg[2];
	44
	45	i2c_msg[0].addr = client->addr;
	46	i2c_msg[0].flags = 0;
	47	i2c_msg[1].addr = client->addr;
	48	i2c_msg[1].flags = I2C_M_RD;
	49
	50	/*
	51	* allocate larger packet (one byte for checksum, one byte for
	52	* length, and one for result code)
	53	*/
5d4773e2	54	packet_len = msg->insize + 3;
89969009 SG	55	in_buf = kzalloc(packet_len, GFP_KERNEL);
	56	if (!in_buf)
	57	goto done;
	58	i2c_msg[1].len = packet_len;
	59	i2c_msg[1].buf = (char *)in_buf;
	60
	61	/*
	62	* allocate larger packet (one byte for checksum, one for
	63	* command code, one for length, and one for command version)
	64	*/
5d4773e2	65	packet_len = msg->outsize + 4;
89969009 SG	66	out_buf = kzalloc(packet_len, GFP_KERNEL);
	67	if (!out_buf)
	68	goto done;
	69	i2c_msg[0].len = packet_len;
	70	i2c_msg[0].buf = (char *)out_buf;
	71
	72	out_buf[0] = EC_CMD_VERSION0 + msg->version;
5d4773e2 BR	73	out_buf[1] = msg->command;
5d4773e2 BR	74	out_buf[2] = msg->outsize;
89969009 SG	75
	76	/* copy message payload and compute checksum */
	77	sum = out_buf[0] + out_buf[1] + out_buf[2];
5d4773e2	78	for (i = 0; i < msg->outsize; i++) {
a8411784	79	out_buf[3 + i] = msg->data[i];
89969009 SG	80	sum += out_buf[3 + i];
89969009 SG	81	}
5d4773e2	82	out_buf[3 + msg->outsize] = sum;
89969009 SG	83
	84	/* send command to EC and read answer */
	85	ret = i2c_transfer(client->adapter, i2c_msg, 2);
	86	if (ret < 0) {
	87	dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
	88	goto done;
	89	} else if (ret != 2) {
	90	dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
	91	ret = -EIO;
	92	goto done;
	93	}
	94
	95	/* check response error code */
6db07b63 BR	96	msg->result = i2c_msg[1].buf[0];
	97	ret = cros_ec_check_result(ec_dev, msg);
	98	if (ret)
89969009	99	goto done;
89969009	100
d6c15ed2 DA	101	len = in_buf[1];
	102	if (len > msg->insize) {
	103	dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
	104	len, msg->insize);
	105	ret = -ENOSPC;
	106	goto done;
	107	}
	108
89969009 SG	109	/* copy response packet payload and compute checksum */
89969009 SG	110	sum = in_buf[0] + in_buf[1];
d6c15ed2	111	for (i = 0; i < len; i++) {
a8411784	112	msg->data[i] = in_buf[2 + i];
89969009 SG	113	sum += in_buf[2 + i];
	114	}
	115	dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
	116	i2c_msg[1].len, in_buf, sum);
d6c15ed2	117	if (sum != in_buf[2 + len]) {
89969009 SG	118	dev_err(ec_dev->dev, "bad packet checksum\n");
	119	ret = -EBADMSG;
	120	goto done;
	121	}
	122
d6c15ed2	123	ret = len;
89969009 SG	124	done:
	125	kfree(in_buf);
	126	kfree(out_buf);
	127	return ret;
	128	}
	129
192afe5e	130	static int cros_ec_i2c_probe(struct i2c_client *client,
89969009 SG	131	const struct i2c_device_id *dev_id)
	132	{
	133	struct device *dev = &client->dev;
	134	struct cros_ec_device *ec_dev = NULL;
	135	int err;
	136
	137	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
	138	if (!ec_dev)
	139	return -ENOMEM;
	140
	141	i2c_set_clientdata(client, ec_dev);
89969009 SG	142	ec_dev->dev = dev;
	143	ec_dev->priv = client;
	144	ec_dev->irq = client->irq;
7e6cb5b4	145	ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
2c7589af	146	ec_dev->pkt_xfer = NULL;
89969009 SG	147	ec_dev->ec_name = client->name;
89969009 SG	148	ec_dev->phys_name = client->adapter->name;
2c7589af SB	149	ec_dev->din_size = sizeof(struct ec_host_response) +
	150	sizeof(struct ec_response_get_protocol_info);
	151	ec_dev->dout_size = sizeof(struct ec_host_request);
89969009 SG	152
	153	err = cros_ec_register(ec_dev);
	154	if (err) {
	155	dev_err(dev, "cannot register EC\n");
	156	return err;
	157	}
	158
	159	return 0;
	160	}
	161
192afe5e	162	static int cros_ec_i2c_remove(struct i2c_client *client)
89969009 SG	163	{
	164	struct cros_ec_device *ec_dev = i2c_get_clientdata(client);
	165
	166	cros_ec_remove(ec_dev);
	167
	168	return 0;
	169	}
	170
	171	#ifdef CONFIG_PM_SLEEP
	172	static int cros_ec_i2c_suspend(struct device *dev)
	173	{
	174	struct cros_ec_device *ec_dev = to_ec_dev(dev);
	175
	176	return cros_ec_suspend(ec_dev);
	177	}
	178
	179	static int cros_ec_i2c_resume(struct device *dev)
	180	{
	181	struct cros_ec_device *ec_dev = to_ec_dev(dev);
	182
	183	return cros_ec_resume(ec_dev);
	184	}
	185	#endif
	186
	187	static SIMPLE_DEV_PM_OPS(cros_ec_i2c_pm_ops, cros_ec_i2c_suspend,
	188	cros_ec_i2c_resume);
	189
	190	static const struct i2c_device_id cros_ec_i2c_id[] = {
	191	{ "cros-ec-i2c", 0 },
	192	{ }
	193	};
	194	MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
	195
	196	static struct i2c_driver cros_ec_driver = {
	197	.driver = {
	198	.name = "cros-ec-i2c",
	199	.owner = THIS_MODULE,
	200	.pm = &cros_ec_i2c_pm_ops,
	201	},
192afe5e TR	202	.probe = cros_ec_i2c_probe,
192afe5e TR	203	.remove = cros_ec_i2c_remove,
89969009 SG	204	.id_table = cros_ec_i2c_id,
	205	};
	206
	207	module_i2c_driver(cros_ec_driver);
	208
	209	MODULE_LICENSE("GPL");
	210	MODULE_DESCRIPTION("ChromeOS EC multi function device");