/**
* cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*/
static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
struct cros_ec_command *ec_msg)
{
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;
int sum;
int ret = 0, final_ret;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
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 */
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);
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_response(ec_dev,
ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
} 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 */
ec_msg->result = ptr[0];
ret = cros_ec_check_result(ec_dev, ec_msg);
if (ret)
goto exit;
len = ptr[1];
sum = ptr[0] + ptr[1];
if (len > ec_msg->insize) {
dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
len, ec_msg->insize);
ret = -ENOSPC;
goto exit;
}
/* copy response packet payload and compute checksum */
for (i = 0; i < len; i++) {
sum += ptr[i + 2];
if (ec_msg->insize)
ec_msg->data[i] = ptr[i + 2];
}
sum &= 0xff;
debug_packet(ec_dev->dev, "in", ptr, len + 3);
if (sum != ptr[len + 2]) {
dev_err(ec_dev->dev,
"bad packet checksum, expected %02x, got %02x\n",
sum, ptr[len + 2]);
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
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*/
static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
struct cros_ec_command *ec_msg)
{
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_transfer trans;
struct spi_message msg;
int i, len;
u8 *ptr;
int sum;
int ret = 0, final_ret;
/*
* We have the shared ec_dev buffer plus we do lots of separate spi_sync
* calls, so we need to make sure only one person is using this at a
* time.
*/
mutex_lock(&ec_spi->lock);
len = cros_ec_prepare_tx(ec_dev, ec_msg);
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);
}
/* 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.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) {
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();
if (!ret)
ret = final_ret;
if (ret < 0) {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
goto exit;
}
ptr = ec_dev->din;
/* check response error code */
ec_msg->result = ptr[0];
ret = cros_ec_check_result(ec_dev, ec_msg);
if (ret)
goto exit;
len = ptr[1];
sum = ptr[0] + ptr[1];
if (len > ec_msg->insize) {
dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
len, ec_msg->insize);
ret = -ENOSPC;
goto exit;
}
/* copy response packet payload and compute checksum */
for (i = 0; i < len; i++) {
sum += ptr[i + 2];
if (ec_msg->insize)
ec_msg->indata[i] = ptr[i + 2];
}
sum &= 0xff;
debug_packet(ec_dev->dev, "in", ptr, len + 3);
if (sum != ptr[len + 2]) {
dev_err(ec_dev->dev,
"bad packet checksum, expected %02x, got %02x\n",
sum, ptr[len + 2]);
ret = -EBADMSG;
goto exit;
}
ret = len;
exit:
mutex_unlock(&ec_spi->lock);
return ret;
}
/**
* cros_ec_command_spi_xfer - Transfer a message over SPI and receive the reply
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*/
static int cros_ec_command_spi_xfer(struct cros_ec_device *ec_dev,
struct cros_ec_msg *ec_msg)
{
struct cros_ec_spi *ec_spi = ec_dev->priv;
struct spi_transfer trans;
struct spi_message msg;
int i, len;
u8 *ptr;
int sum;
int ret = 0, final_ret;
struct timespec ts;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
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) {
struct timespec ts;
unsigned long delay; /* The delay completed so far */
ktime_get_ts(&ts);
delay = timespec_to_ns(&ts) - ec_spi->last_transfer_ns;
if (delay < EC_SPI_RECOVERY_TIME_NS)
ndelay(delay);
}
/* 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.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) {
ret = cros_ec_spi_receive_response(ec_dev,
ec_msg->in_len + EC_MSG_TX_PROTO_BYTES);
} else {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
}
/* turn off CS */
spi_message_init(&msg);
final_ret = spi_sync(ec_spi->spi, &msg);
ktime_get_ts(&ts);
ec_spi->last_transfer_ns = timespec_to_ns(&ts);
if (!ret)
ret = final_ret;
if (ret < 0) {
dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
return ret;
}
/* check response error code */
ptr = ec_dev->din;
if (ptr[0]) {
dev_warn(ec_dev->dev, "command 0x%02x returned an error %d\n",
ec_msg->cmd, ptr[0]);
debug_packet(ec_dev->dev, "in_err", ptr, len);
return -EINVAL;
}
len = ptr[1];
sum = ptr[0] + ptr[1];
if (len > ec_msg->in_len) {
dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
len, ec_msg->in_len);
return -ENOSPC;
}
/* copy response packet payload and compute checksum */
for (i = 0; i < len; i++) {
sum += ptr[i + 2];
if (ec_msg->in_len)
ec_msg->in_buf[i] = ptr[i + 2];
}
sum &= 0xff;
debug_packet(ec_dev->dev, "in", ptr, len + 3);
if (sum != ptr[len + 2]) {
dev_err(ec_dev->dev,
"bad packet checksum, expected %02x, got %02x\n",
sum, ptr[len + 2]);
return -EBADMSG;
}
return 0;
}
