From 0a9b2d1ce42210d087d32b1979d3ada343537708 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Sat, 13 Apr 2019 11:32:57 +0100 Subject: [PATCH] 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: Fabrice Gasnier Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 37 ++++++++++++++++++++++++++++++++++ include/linux/nvmem-consumer.h | 7 +++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index f24008b66826..1d00f5671368 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -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 * diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h index 312bfa5efd80..8f8be5b00060 100644 --- a/include/linux/nvmem-consumer.h +++ b/include/linux/nvmem-consumer.h @@ -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) { -- 2.30.2