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platform/chrome: cros_ec_lpc: MEC access can return error code

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cros_ec_lpc_io_bytes_mec was returning a u8 checksum of all bytes
read/written, which didn't leave room to indicate errors. Change this
u8 to an int where negative values indicate an error, and non-negative
values are the checksum as before.

Tested-by: Dustin L. Howett <dustin@howett.net>
Signed-off-by: Ben Walsh <ben@jubnut.com>
Link: https://lore.kernel.org/r/20240605063351.14836-2-ben@jubnut.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
This commit is contained in:
Ben Walsh 2024-06-05 07:33:47 +01:00 • committed by Tzung-Bi Shih
parent 106d673982
commit 68dbac0a58
4 changed files with 112 additions and 56 deletions
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130
drivers/platform/chrome/cros_ec_lpc.c
View file

@ -62,14 +62,16 @@ struct cros_ec_lpc {
/**
* struct lpc_driver_ops - LPC driver operations
* @read: Copy length bytes from EC address offset into buffer dest. Returns
* the 8-bit checksum of all bytes read.
* @write: Copy length bytes from buffer msg into EC address offset. Returns
* the 8-bit checksum of all bytes written.
* @read: Copy length bytes from EC address offset into buffer dest.
* Returns a negative error code on error, or the 8-bit checksum
* of all bytes read.
* @write: Copy length bytes from buffer msg into EC address offset.
* Returns a negative error code on error, or the 8-bit checksum
* of all bytes written.
*/
struct lpc_driver_ops {
u8 (*read)(unsigned int offset, unsigned int length, u8 *dest);
u8 (*write)(unsigned int offset, unsigned int length, const u8 *msg);
int (*read)(unsigned int offset, unsigned int length, u8 *dest);
int (*write)(unsigned int offset, unsigned int length, const u8 *msg);
};
static struct lpc_driver_ops cros_ec_lpc_ops = { };
@ -78,10 +80,10 @@ static struct lpc_driver_ops cros_ec_lpc_ops = { };
* A generic instance of the read function of struct lpc_driver_ops, used for
* the LPC EC.
*/
static u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
u8 *dest)
static int cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
u8 *dest)
{
int sum = 0;
u8 sum = 0;
int i;
for (i = 0; i < length; ++i) {
@ -97,10 +99,10 @@ static u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
* A generic instance of the write function of struct lpc_driver_ops, used for
* the LPC EC.
*/
static u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
const u8 *msg)
static int cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
const u8 *msg)
{
int sum = 0;
u8 sum = 0;
int i;
for (i = 0; i < length; ++i) {
@ -116,8 +118,8 @@ static u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
* An instance of the read function of struct lpc_driver_ops, used for the
* MEC variant of LPC EC.
*/
static u8 cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
u8 *dest)
static int cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
u8 *dest)
{
int in_range = cros_ec_lpc_mec_in_range(offset, length);
@ -135,8 +137,8 @@ static u8 cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
* An instance of the write function of struct lpc_driver_ops, used for the
* MEC variant of LPC EC.
*/
static u8 cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length,
const u8 *msg)
static int cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length,
const u8 *msg)
{
int in_range = cros_ec_lpc_mec_in_range(offset, length);
@ -154,11 +156,14 @@ static int ec_response_timed_out(void)
{
unsigned long one_second = jiffies + HZ;
u8 data;
int ret;
usleep_range(200, 300);
do {
if (!(cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_CMD, 1, &data) &
EC_LPC_STATUS_BUSY_MASK))
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_CMD, 1, &data);
if (ret < 0)
return ret;
if (!(data & EC_LPC_STATUS_BUSY_MASK))
return 0;
usleep_range(100, 200);
} while (time_before(jiffies, one_second));
@ -179,28 +184,41 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
goto done;
/* Write buffer */
cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
if (ret < 0)
goto done;
/* Here we go */
sum = EC_COMMAND_PROTOCOL_3;
cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
if (ret < 0)
goto done;
if (ec_response_timed_out()) {
ret = ec_response_timed_out();
if (ret < 0)
goto done;
if (ret) {
dev_warn(ec->dev, "EC response timed out\n");
ret = -EIO;
goto done;
}
/* Check result */
msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
if (ret < 0)
goto done;
msg->result = ret;
ret = cros_ec_check_result(ec, msg);
if (ret)
goto done;
/* Read back response */
dout = (u8 *)&response;
sum = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
dout);
if (ret < 0)
goto done;
sum = ret;
msg->result = response.result;
@ -213,9 +231,12 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
}
/* Read response and process checksum */
sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET +
sizeof(response), response.data_len,
msg->data);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET +
sizeof(response), response.data_len,
msg->data);
if (ret < 0)
goto done;
sum += ret;
if (sum) {
dev_err(ec->dev,
@ -255,32 +276,47 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
sum = msg->command + args.flags + args.command_version + args.data_size;
/* Copy data and update checksum */
sum += cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
msg->data);
ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
msg->data);
if (ret < 0)
goto done;
sum += ret;
/* Finalize checksum and write args */
args.checksum = sum;
cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
(u8 *)&args);
ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
(u8 *)&args);
if (ret < 0)
goto done;
/* Here we go */
sum = msg->command;
cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
ret = cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
if (ret < 0)
goto done;
if (ec_response_timed_out()) {
ret = ec_response_timed_out();
if (ret < 0)
goto done;
if (ret) {
dev_warn(ec->dev, "EC response timed out\n");
ret = -EIO;
goto done;
}
/* Check result */
msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
if (ret < 0)
goto done;
msg->result = ret;
ret = cros_ec_check_result(ec, msg);
if (ret)
goto done;
/* Read back args */
cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_ARGS, sizeof(args), (u8 *)&args);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_ARGS, sizeof(args), (u8 *)&args);
if (ret < 0)
goto done;
if (args.data_size > msg->insize) {
dev_err(ec->dev,
@ -294,8 +330,11 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
sum = msg->command + args.flags + args.command_version + args.data_size;
/* Read response and update checksum */
sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PARAM, args.data_size,
msg->data);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PARAM, args.data_size,
msg->data);
if (ret < 0)
goto done;
sum += ret;
/* Verify checksum */
if (args.checksum != sum) {
@ -320,19 +359,24 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
int i = offset;
char *s = dest;
int cnt = 0;
int ret;
if (offset >= EC_MEMMAP_SIZE - bytes)
return -EINVAL;
/* fixed length */
if (bytes) {
cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + offset, bytes, s);
ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + offset, bytes, s);
if (ret < 0)
return ret;
return bytes;
}
/* string */
for (; i < EC_MEMMAP_SIZE; i++, s++) {
cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + i, 1, s);
ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + i, 1, s);
if (ret < 0)
return ret;
cnt++;
if (!*s)
break;
@ -425,7 +469,9 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
*/
cros_ec_lpc_ops.read = cros_ec_lpc_mec_read_bytes;
cros_ec_lpc_ops.write = cros_ec_lpc_mec_write_bytes;
cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
ret = cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
if (ret < 0)
return ret;
if (buf[0] != 'E' || buf[1] != 'C') {
if (!devm_request_region(dev, ec_lpc->mmio_memory_base, EC_MEMMAP_SIZE,
dev_name(dev))) {
@ -436,8 +482,10 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
/* Re-assign read/write operations for the non MEC variant */
cros_ec_lpc_ops.read = cros_ec_lpc_read_bytes;
cros_ec_lpc_ops.write = cros_ec_lpc_write_bytes;
cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + EC_MEMMAP_ID, 2,
buf);
ret = cros_ec_lpc_ops.read(ec_lpc->mmio_memory_base + EC_MEMMAP_ID, 2,
buf);
if (ret < 0)
return ret;
if (buf[0] != 'E' || buf[1] != 'C') {
dev_err(dev, "EC ID not detected\n");
return -ENODEV;

9
drivers/platform/chrome/cros_ec_lpc_mec.c
View file

@ -67,11 +67,12 @@ int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length)
* @length: Number of bytes to read / write
* @buf: Destination / source buffer
*
* Return: 8-bit checksum of all bytes read / written
* @return: A negative error code on error, or 8-bit checksum of all
* bytes read / written
*/
u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
unsigned int offset, unsigned int length,
u8 *buf)
int cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
unsigned int offset, unsigned int length,
u8 *buf)
{
int i = 0;
int io_addr;

7
drivers/platform/chrome/cros_ec_lpc_mec.h
View file

@ -64,9 +64,10 @@ int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length);
* @length: Number of bytes to read / write
* @buf: Destination / source buffer
*
* @return 8-bit checksum of all bytes read / written
* @return: A negative error code on error, or 8-bit checksum of all
* bytes read / written
*/
u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
unsigned int offset, unsigned int length, u8 *buf);
int cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
unsigned int offset, unsigned int length, u8 *buf);
#endif /* __CROS_EC_LPC_MEC_H */

22
drivers/platform/chrome/wilco_ec/mailbox.c
View file

@ -117,13 +117,17 @@ static int wilco_ec_transfer(struct wilco_ec_device *ec,
struct wilco_ec_request *rq)
{
struct wilco_ec_response *rs;
u8 checksum;
int ret;
u8 flag;
/* Write request header, then data */
cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE, 0, sizeof(*rq), (u8 *)rq);
cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE, sizeof(*rq), msg->request_size,
msg->request_data);
ret = cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE, 0, sizeof(*rq), (u8 *)rq);
if (ret < 0)
return ret;
ret = cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE, sizeof(*rq), msg->request_size,
msg->request_data);
if (ret < 0)
return ret;
/* Start the command */
outb(EC_MAILBOX_START_COMMAND, ec->io_command->start);
@ -149,10 +153,12 @@ static int wilco_ec_transfer(struct wilco_ec_device *ec,
/* Read back response */
rs = ec->data_buffer;
checksum = cros_ec_lpc_io_bytes_mec(MEC_IO_READ, 0,
sizeof(*rs) + EC_MAILBOX_DATA_SIZE,
(u8 *)rs);
if (checksum) {
ret = cros_ec_lpc_io_bytes_mec(MEC_IO_READ, 0,
sizeof(*rs) + EC_MAILBOX_DATA_SIZE,
(u8 *)rs);
if (ret < 0)
return ret;
if (ret) {
dev_dbg(ec->dev, "bad packet checksum 0x%02x\n", rs->checksum);
return -EBADMSG;
}