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nvmem: core: add nvmem_cell_read_u16

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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: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Fabrice Gasnier 2019-04-13 11:32:57 +01:00 committed by Greg Kroah-Hartman
parent 7c1cd8fda8
commit 0a9b2d1ce4
2 changed files with 44 additions and 0 deletions
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37
drivers/nvmem/core.c
View File

@ -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
*

7
include/linux/nvmem-consumer.h
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_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)
{