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Commit 0a9b2d1c authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Greg Kroah-Hartman
Browse files

nvmem: core: add nvmem_cell_read_u16 



Add nvmem_cell_read_u16() helper to ease read of an u16 value on consumer
side. This is inspired by nvmem_cell_read_u32() function.
This helper is useful on stm32 that has 16 bits data cells stored in non
volatile memory.

Signed-off-by: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7c1cd8fd

drivers/nvmem/core.c

+37 −0
Original line number Diff line number Diff line
@@ -1334,6 +1334,43 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) 
}

EXPORT_SYMBOL_GPL(nvmem_cell_write);



/**

 * nvmem_cell_read_u16() - Read a cell value as an u16

 *

 * @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_u16(struct device *dev, const char *cell_id, u16 *val)

{

	struct nvmem_cell *cell;

	void *buf;

	size_t len;



	cell = nvmem_cell_get(dev, cell_id);

	if (IS_ERR(cell))

		return PTR_ERR(cell);



	buf = nvmem_cell_read(cell, &len);

	if (IS_ERR(buf)) {

		nvmem_cell_put(cell);

		return PTR_ERR(buf);

	}

	if (len != sizeof(*val)) {

		kfree(buf);

		nvmem_cell_put(cell);

		return -EINVAL;

	}

	memcpy(val, buf, sizeof(*val));

	kfree(buf);

	nvmem_cell_put(cell);



	return 0;

}

EXPORT_SYMBOL_GPL(nvmem_cell_read_u16);



/**

 * nvmem_cell_read_u32() - Read a cell value as an u32

 *

include/linux/nvmem-consumer.h

+7 −0
Original line number Diff line number Diff line
@@ -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_u16(struct device *dev, const char *cell_id, u16 *val);

int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val);



/* direct nvmem device read/write interface */
@@ -122,6 +123,12 @@ static inline int nvmem_cell_write(struct nvmem_cell *cell, 
	return -EOPNOTSUPP;

}



static inline int nvmem_cell_read_u16(struct device *dev,

				      const char *cell_id, u16 *val)

{

	return -EOPNOTSUPP;

}



static inline int nvmem_cell_read_u32(struct device *dev,

				      const char *cell_id, u32 *val)

{