nvmem: core: Add nvmem_cell_read_u8()

Complement the u16, u32 and u64 helpers with a u8 variant to ease
accessing byte-sized values.

This helper will be useful for Realtek Digital Home Center platforms,
which store some byte and sub-byte sized values in non-volatile memory.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200722100705.7772-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andreas Färber 2020-07-22 11:06:57 +01:00 committed by Greg Kroah-Hartman
parent 3a7580710b
commit 5037d368b2
2 changed files with 16 additions and 0 deletions

View File

@ -1374,6 +1374,21 @@ static int nvmem_cell_read_common(struct device *dev, const char *cell_id,
return 0;
}
/**
* nvmem_cell_read_u8() - Read a cell value as a u8
*
* @dev: Device that requests the nvmem cell.
* @cell_id: Name of nvmem cell to read.
* @val: pointer to output value.
*
* Return: 0 on success or negative errno.
*/
int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val)
{
return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val));
}
EXPORT_SYMBOL_GPL(nvmem_cell_read_u8);
/**
* nvmem_cell_read_u16() - Read a cell value as a u16
*

View File

@ -61,6 +61,7 @@ void nvmem_cell_put(struct nvmem_cell *cell);
void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell);
void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len);
int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len);
int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val);
int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val);
int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val);
int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val);