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mfd: cros_ec: add bus-specific proto v3 code 

Add proto v3 support to the SPI, I2C, and LPC.

Signed-off-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Stephen Barber 2015-06-09 13:04:46 +02:00 committed by Lee Jones
parent 2c7589af3c
commit d365407079
4 changed files with 569 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

166
drivers/mfd/cros_ec_i2c.c
View File

@ -13,6 +13,7 @@
* GNU General Public License for more details.
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
@ -22,6 +23,32 @@
#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);
@ -29,6 +56,134 @@ static inline struct cros_ec_device *to_ec_dev(struct device *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)
{
@ -121,9 +276,12 @@ static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
}
ret = len;
done:
done:
kfree(in_buf);
kfree(out_buf);
if (msg->command == EC_CMD_REBOOT_EC)
msleep(EC_REBOOT_DELAY_MS);
return ret;
}
@ -143,12 +301,12 @@ static int cros_ec_i2c_probe(struct i2c_client *client,
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->pkt_xfer = cros_ec_pkt_xfer_i2c;
ec_dev->ec_name = client->name;
ec_dev->phys_name = client->adapter->name;
ec_dev->din_size = sizeof(struct ec_host_response) +
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);
ec_dev->dout_size = sizeof(struct ec_host_request_i2c);
err = cros_ec_register(ec_dev);
if (err) {

382
drivers/mfd/cros_ec_spi.c
View File

@ -65,12 +65,6 @@
*/
#define EC_SPI_RECOVERY_TIME_NS (200 * 1000)
/*
* The EC is unresponsive for a time after a reboot command. Add a
* simple delay to make sure that the bus stays locked.
*/
#define EC_REBOOT_DELAY_MS 50
/**
* struct cros_ec_spi - information about a SPI-connected EC
*
@ -87,7 +81,7 @@ struct cros_ec_spi {
};
static void debug_packet(struct device *dev, const char *name, u8 *ptr,
int len)
int len)
{
#ifdef DEBUG
int i;
@ -100,6 +94,172 @@ static void debug_packet(struct device *dev, const char *name, u8 *ptr,
#endif
}
static int terminate_request(struct cros_ec_device *ec_dev)
{
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_message msg;
struct spi_transfer trans;
int ret;
/*
* Turn off CS, possibly adding a delay to ensure the rising edge
* doesn't come too soon after the end of the data.
*/
spi_message_init(&msg);
memset(&trans, 0, sizeof(trans));
trans.delay_usecs = ec_spi->end_of_msg_delay;
spi_message_add_tail(&trans, &msg);
ret = spi_sync(ec_spi->spi, &msg);
/* Reset end-of-response timer */
ec_spi->last_transfer_ns = ktime_get_ns();
if (ret < 0) {
dev_err(ec_dev->dev,
"cs-deassert spi transfer failed: %d\n",
ret);
}
return ret;
}
/**
* receive_n_bytes - receive n bytes from the EC.
*
* Assumes buf is a pointer into the ec_dev->din buffer
*/
static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
{
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_transfer trans;
struct spi_message msg;
int ret;
BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
memset(&trans, 0, sizeof(trans));
trans.cs_change = 1;
trans.rx_buf = buf;
trans.len = n;
spi_message_init(&msg);
spi_message_add_tail(&trans, &msg);
ret = spi_sync(ec_spi->spi, &msg);
if (ret < 0)
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
return ret;
}
/**
* cros_ec_spi_receive_packet - Receive a packet from the EC.
*
* This function has two phases: reading the preamble bytes (since if we read
* data from the EC before it is ready to send, we just get preamble) and
* reading the actual message.
*
* The received data is placed into ec_dev->din.
*
* @ec_dev: ChromeOS EC device
* @need_len: Number of message bytes we need to read
*/
static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
int need_len)
{
struct ec_host_response *response;
u8 *ptr, *end;
int ret;
unsigned long deadline;
int todo;
BUG_ON(EC_MSG_PREAMBLE_COUNT > ec_dev->din_size);
/* Receive data until we see the header byte */
deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
while (true) {
unsigned long start_jiffies = jiffies;
ret = receive_n_bytes(ec_dev,
ec_dev->din,
EC_MSG_PREAMBLE_COUNT);
if (ret < 0)
return ret;
ptr = ec_dev->din;
for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
if (*ptr == EC_SPI_FRAME_START) {
dev_dbg(ec_dev->dev, "msg found at %zd\n",
ptr - ec_dev->din);
break;
}
}
if (ptr != end)
break;
/*
* Use the time at the start of the loop as a timeout. This
* gives us one last shot at getting the transfer and is useful
* in case we got context switched out for a while.
*/
if (time_after(start_jiffies, deadline)) {
dev_warn(ec_dev->dev, "EC failed to respond in time\n");
return -ETIMEDOUT;
}
}
/*
* ptr now points to the header byte. Copy any valid data to the
* start of our buffer
*/
todo = end - ++ptr;
BUG_ON(todo < 0 || todo > ec_dev->din_size);
todo = min(todo, need_len);
memmove(ec_dev->din, ptr, todo);
ptr = ec_dev->din + todo;
dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
need_len, todo);
need_len -= todo;
/* If the entire response struct wasn't read, get the rest of it. */
if (todo < sizeof(*response)) {
ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);
if (ret < 0)
return -EBADMSG;
ptr += (sizeof(*response) - todo);
todo = sizeof(*response);
}
response = (struct ec_host_response *)ec_dev->din;
/* Abort if data_len is too large. */
if (response->data_len > ec_dev->din_size)
return -EMSGSIZE;
/* Receive data until we have it all */
while (need_len > 0) {
/*
* We can't support transfers larger than the SPI FIFO size
* unless we have DMA. We don't have DMA on the ISP SPI ports
* for Exynos. We need a way of asking SPI driver for
* maximum-supported transfer size.
*/
todo = min(need_len, 256);
dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
todo, need_len, ptr - ec_dev->din);
ret = receive_n_bytes(ec_dev, ptr, todo);
if (ret < 0)
return ret;
ptr += todo;
need_len -= todo;
}
dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
return 0;
}
/**
* cros_ec_spi_receive_response - Receive a response from the EC.
*
@ -115,34 +275,27 @@ static void debug_packet(struct device *dev, const char *name, u8 *ptr,
static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
int need_len)
{
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_transfer trans;
struct spi_message msg;
u8 *ptr, *end;
int ret;
unsigned long deadline;
int todo;
BUG_ON(EC_MSG_PREAMBLE_COUNT > ec_dev->din_size);
/* Receive data until we see the header byte */
deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
while (true) {
unsigned long start_jiffies = jiffies;
memset(&trans, 0, sizeof(trans));
trans.cs_change = 1;
trans.rx_buf = ptr = ec_dev->din;
trans.len = EC_MSG_PREAMBLE_COUNT;
spi_message_init(&msg);
spi_message_add_tail(&trans, &msg);
ret = spi_sync(ec_spi->spi, &msg);
if (ret < 0) {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
ret = receive_n_bytes(ec_dev,
ec_dev->din,
EC_MSG_PREAMBLE_COUNT);
if (ret < 0)
return ret;
}
ptr = ec_dev->din;
for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
if (*ptr == EC_MSG_HEADER) {
if (*ptr == EC_SPI_FRAME_START) {
dev_dbg(ec_dev->dev, "msg found at %zd\n",
ptr - ec_dev->din);
break;
@ -187,21 +340,9 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
todo, need_len, ptr - ec_dev->din);
memset(&trans, 0, sizeof(trans));
trans.cs_change = 1;
trans.rx_buf = ptr;
trans.len = todo;
spi_message_init(&msg);
spi_message_add_tail(&trans, &msg);
/* send command to EC and read answer */
BUG_ON((u8 *)trans.rx_buf - ec_dev->din + todo >
ec_dev->din_size);
ret = spi_sync(ec_spi->spi, &msg);
if (ret < 0) {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
ret = receive_n_bytes(ec_dev, ptr, todo);
if (ret < 0)
return ret;
}
debug_packet(ec_dev->dev, "interim", ptr, todo);
ptr += todo;
@ -213,6 +354,128 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
return 0;
}
/**
* cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*/
static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
struct cros_ec_command *ec_msg)
{
struct ec_host_request *request;
struct ec_host_response *response;
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_transfer trans;
struct spi_message msg;
int i, len;
u8 *ptr;
u8 *rx_buf;
u8 sum;
int ret = 0, final_ret;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
request = (struct ec_host_request *)ec_dev->dout;
dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
/* If it's too soon to do another transaction, wait */
if (ec_spi->last_transfer_ns) {
unsigned long delay; /* The delay completed so far */
delay = ktime_get_ns() - ec_spi->last_transfer_ns;
if (delay < EC_SPI_RECOVERY_TIME_NS)
ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
}
rx_buf = kzalloc(len, GFP_KERNEL);
if (!rx_buf) {
ret = -ENOMEM;
goto exit;
}
/* Transmit phase - send our message */
memset(&trans, 0, sizeof(trans));
trans.tx_buf = ec_dev->dout;
trans.rx_buf = rx_buf;
trans.len = len;
trans.cs_change = 1;
spi_message_init(&msg);
spi_message_add_tail(&trans, &msg);
ret = spi_sync(ec_spi->spi, &msg);
/* Get the response */
if (!ret) {
/* Verify that EC can process command */
for (i = 0; i < len; i++) {
switch (rx_buf[i]) {
case EC_SPI_PAST_END:
case EC_SPI_RX_BAD_DATA:
case EC_SPI_NOT_READY:
ret = -EAGAIN;
ec_msg->result = EC_RES_IN_PROGRESS;
default:
break;
}
if (ret)
break;
}
if (!ret)
ret = cros_ec_spi_receive_packet(ec_dev,
ec_msg->insize + sizeof(*response));
} else {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
}
final_ret = terminate_request(ec_dev);
if (!ret)
ret = final_ret;
if (ret < 0)
goto exit;
ptr = ec_dev->din;
/* check response error code */
response = (struct ec_host_response *)ptr;
ec_msg->result = response->result;
ret = cros_ec_check_result(ec_dev, ec_msg);
if (ret)
goto exit;
len = response->data_len;
sum = 0;
if (len > ec_msg->insize) {
dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
len, ec_msg->insize);
ret = -EMSGSIZE;
goto exit;
}
for (i = 0; i < sizeof(*response); i++)
sum += ptr[i];
/* copy response packet payload and compute checksum */
memcpy(ec_msg->data, ptr + sizeof(*response), len);
for (i = 0; i < len; i++)
sum += ec_msg->data[i];
if (sum) {
dev_err(ec_dev->dev,
"bad packet checksum, calculated %x\n",
sum);
ret = -EBADMSG;
goto exit;
}
ret = len;
exit:
kfree(rx_buf);
if (ec_msg->command == EC_CMD_REBOOT_EC)
msleep(EC_REBOOT_DELAY_MS);
return ret;
}
/**
* cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
*
@ -227,6 +490,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
struct spi_message msg;
int i, len;
u8 *ptr;
u8 *rx_buf;
int sum;
int ret = 0, final_ret;
@ -242,10 +506,17 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
}
rx_buf = kzalloc(len, GFP_KERNEL);
if (!rx_buf) {
ret = -ENOMEM;
goto exit;
}
/* Transmit phase - send our message */
debug_packet(ec_dev->dev, "out", ec_dev->dout, len);
memset(&trans, 0, sizeof(trans));
trans.tx_buf = ec_dev->dout;
trans.rx_buf = rx_buf;
trans.len = len;
trans.cs_change = 1;
spi_message_init(&msg);
@ -254,29 +525,32 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
/* Get the response */
if (!ret) {
ret = cros_ec_spi_receive_response(ec_dev,
ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
/* Verify that EC can process command */
for (i = 0; i < len; i++) {
switch (rx_buf[i]) {
case EC_SPI_PAST_END:
case EC_SPI_RX_BAD_DATA:
case EC_SPI_NOT_READY:
ret = -EAGAIN;
ec_msg->result = EC_RES_IN_PROGRESS;
default:
break;
}
if (ret)
break;
}
if (!ret)
ret = cros_ec_spi_receive_response(ec_dev,
ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
} else {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
}
/*
* Turn off CS, possibly adding a delay to ensure the rising edge
* doesn't come too soon after the end of the data.
*/
spi_message_init(&msg);
memset(&trans, 0, sizeof(trans));
trans.delay_usecs = ec_spi->end_of_msg_delay;
spi_message_add_tail(&trans, &msg);
final_ret = spi_sync(ec_spi->spi, &msg);
ec_spi->last_transfer_ns = ktime_get_ns();
final_ret = terminate_request(ec_dev);
if (!ret)
ret = final_ret;
if (ret < 0) {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
if (ret < 0)
goto exit;
}
ptr = ec_dev->din;
@ -315,6 +589,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
ret = len;
exit:
kfree(rx_buf);
if (ec_msg->command == EC_CMD_REBOOT_EC)
msleep(EC_REBOOT_DELAY_MS);
@ -361,7 +636,7 @@ static int cros_ec_spi_probe(struct spi_device *spi)
ec_dev->priv = ec_spi;
ec_dev->irq = spi->irq;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
ec_dev->pkt_xfer = NULL;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
ec_dev->ec_name = ec_spi->spi->modalias;
ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
@ -369,6 +644,7 @@ static int cros_ec_spi_probe(struct spi_device *spi)
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");

73
drivers/platform/chrome/cros_ec_lpc.c
View File

@ -46,6 +46,77 @@ static int ec_response_timed_out(void)
return 1;
}
static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
struct cros_ec_command *msg)
{
struct ec_host_request *request;
struct ec_host_response response;
u8 sum = 0;
int i;
int ret = 0;
u8 *dout;
ret = cros_ec_prepare_tx(ec, msg);
/* Write buffer */
for (i = 0; i < ret; i++)
outb(ec->dout[i], EC_LPC_ADDR_HOST_PACKET + i);
request = (struct ec_host_request *)ec->dout;
/* Here we go */
outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD);
if (ec_response_timed_out()) {
dev_warn(ec->dev, "EC responsed timed out\n");
ret = -EIO;
goto done;
}
/* Check result */
msg->result = inb(EC_LPC_ADDR_HOST_DATA);
ret = cros_ec_check_result(ec, msg);
if (ret)
goto done;
/* Read back response */
dout = (u8 *)&response;
for (i = 0; i < sizeof(response); i++) {
dout[i] = inb(EC_LPC_ADDR_HOST_PACKET + i);
sum += dout[i];
}
msg->result = response.result;
if (response.data_len > msg->insize) {
dev_err(ec->dev,
"packet too long (%d bytes, expected %d)",
response.data_len, msg->insize);
ret = -EMSGSIZE;
goto done;
}
/* Read response and process checksum */
for (i = 0; i < response.data_len; i++) {
msg->data[i] =
inb(EC_LPC_ADDR_HOST_PACKET + sizeof(response) + i);
sum += msg->data[i];
}
if (sum) {
dev_err(ec->dev,
"bad packet checksum %02x\n",
response.checksum);
ret = -EBADMSG;
goto done;
}
/* Return actual amount of data received */
ret = response.data_len;
done:
return ret;
}
static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
struct cros_ec_command *msg)
{
@ -215,7 +286,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
ec_dev->ec_name = pdev->name;
ec_dev->phys_name = dev_name(dev);
ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
ec_dev->pkt_xfer = NULL;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
ec_dev->cmd_readmem = cros_ec_lpc_readmem;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);

6
include/linux/mfd/cros_ec.h
View File

@ -21,6 +21,12 @@
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>
/*
* The EC is unresponsive for a time after a reboot command. Add a
* simple delay to make sure that the bus stays locked.
*/
#define EC_REBOOT_DELAY_MS 50
/*
* Max bus-specific overhead incurred by request/responses.
* I2C requires 1 additional byte for requests.