Commit a14a569a authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Tzung-Bi Shih
Browse files

platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_readmem() 



To read from the EC memory different mechanism are possible.
ECs connected via LPC expose their memory via a ->cmd_readmem operation.
Other protocols require the usage of EC_CMD_READ_MEMMAP, which on the
other hand is not implemented by LPC ECs.

Provide a helper that automatically selects the correct mechanism.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240529-cros_ec-hwmon-v4-1-5cdf0c5db50a@weissschuh.net


Signed-off-by: default avatarTzung-Bi Shih <tzungbi@kernel.org>
parent 7b44d538

drivers/platform/chrome/cros_ec_proto.c

+27 −0
Original line number Diff line number Diff line
@@ -1033,3 +1033,30 @@ int cros_ec_cmd(struct cros_ec_device *ec_dev, 
	return ret;

}

EXPORT_SYMBOL_GPL(cros_ec_cmd);



/**

 * cros_ec_cmd_readmem - Read from EC memory.

 *

 * @ec_dev: EC device

 * @offset: Is within EC_LPC_ADDR_MEMMAP region.

 * @size: Number of bytes to read.

 * @dest: EC command output data

 *

 * Return: >= 0 on success, negative error number on failure.

 */

int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest)

{

	struct ec_params_read_memmap params = {};



	if (!size)

		return -EINVAL;



	if (ec_dev->cmd_readmem)

		return ec_dev->cmd_readmem(ec_dev, offset, size, dest);



	params.offset = offset;

	params.size = size;

	return cros_ec_cmd(ec_dev, 0, EC_CMD_READ_MEMMAP,

			   &params, sizeof(params), dest, size);

}

EXPORT_SYMBOL_GPL(cros_ec_cmd_readmem);

include/linux/platform_data/cros_ec_proto.h

+2 −0
Original line number Diff line number Diff line
@@ -261,6 +261,8 @@ int cros_ec_get_sensor_count(struct cros_ec_dev *ec); 
int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command, const void *outdata,

		    size_t outsize, void *indata, size_t insize);



int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);



/**

 * cros_ec_get_time_ns() - Return time in ns.

 *