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authorFabrice Gasnier <fabrice.gasnier@st.com>2019-04-13 13:32:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-25 20:43:12 +0300
commit0a9b2d1ce42210d087d32b1979d3ada343537708 (patch)
treea30eb5aac596803d9a18e70c687c11d6071ca657 /drivers/nvmem/core.c
parent7c1cd8fda8fbcc3701f372003ef0a3b6d31e11f4 (diff)
downloadlinux-0a9b2d1ce42210d087d32b1979d3ada343537708.tar.xz
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 <fabrice.gasnier@st.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem/core.c')
-rw-r--r--drivers/nvmem/core.c37
1 files changed, 37 insertions, 0 deletions
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
@@ -1335,6 +1335,43 @@ 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
*
* @dev: Device that requests the nvmem cell.