375 lines
9.1 KiB
C
375 lines
9.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
// I2C interface for ChromeOS Embedded Controller
|
||
|
|
//
|
||
|
|
// Copyright (C) 2012 Google, Inc
|
||
|
|
|
||
|
|
#include <linux/acpi.h>
|
||
|
|
#include <linux/delay.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/i2c.h>
|
||
|
|
#include <linux/interrupt.h>
|
||
|
|
#include <linux/platform_data/cros_ec_commands.h>
|
||
|
|
#include <linux/platform_data/cros_ec_proto.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);
|
||
|
|
|
||
|
|
return cros_ec_unregister(ec_dev);
|
||
|
|
}
|
||
|
|
|
||
|
|
#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 const struct dev_pm_ops cros_ec_i2c_pm_ops = {
|
||
|
|
SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_i2c_suspend, cros_ec_i2c_resume)
|
||
|
|
};
|
||
|
|
|
||
|
|
#ifdef CONFIG_OF
|
||
|
|
static const struct of_device_id cros_ec_i2c_of_match[] = {
|
||
|
|
{ .compatible = "google,cros-ec-i2c", },
|
||
|
|
{ /* sentinel */ },
|
||
|
|
};
|
||
|
|
MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static const struct i2c_device_id cros_ec_i2c_id[] = {
|
||
|
|
{ "cros-ec-i2c", 0 },
|
||
|
|
{ }
|
||
|
|
};
|
||
|
|
MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
|
||
|
|
|
||
|
|
#ifdef CONFIG_ACPI
|
||
|
|
static const struct acpi_device_id cros_ec_i2c_acpi_id[] = {
|
||
|
|
{ "GOOG0008", 0 },
|
||
|
|
{ /* sentinel */ }
|
||
|
|
};
|
||
|
|
MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_acpi_id);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static struct i2c_driver cros_ec_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = "cros-ec-i2c",
|
||
|
|
.acpi_match_table = ACPI_PTR(cros_ec_i2c_acpi_id),
|
||
|
|
.of_match_table = of_match_ptr(cros_ec_i2c_of_match),
|
||
|
|
.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 v2");
|
||
|
|
MODULE_DESCRIPTION("I2C interface for ChromeOS Embedded Controller");
|