Re: [PATCH v7 2/9] nvmem: Add a simple NVMEM framework for consumers

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c

@@ -334,6 +335,7 @@ struct nvmem_device *nvmem_register(struct nvmem_config *config)
 	if (config->cells)
 		nvmem_add_cells(nvmem, config);
 
+

+static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id)
+{
+	struct nvmem_cell *cell = NULL;
+	struct nvmem_device *nvmem;
+
+	nvmem = __nvmem_device_get(NULL, &cell, cell_id);
+	if (IS_ERR(nvmem))
+		return ERR_CAST(nvmem);
+
+

+/**
+ * nvmem_cell_read() - Read a given nvmem cell
+ *
+ * @cell: nvmem cell to be read.
+ * @len: pointer to length of cell which will be populated on successful read.
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a char * bufffer.  The buffer should be freed by the consumer with a

+ * kfree().
+ */
+void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
+{
+	struct nvmem_device *nvmem = cell->nvmem;
+	u8 *buf;

+	return buf;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read);

+/**
+ * nvmem_cell_write() - Write to a given nvmem cell
+ *
+ * @cell: nvmem cell to be written.
+ * @buf: Buffer to be written.
+ * @len: length of buffer to be written to nvmem cell.
+ *
+ * The return value will be an length of bytes written or non zero on failure.

+ */
+int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
+{
+	struct nvmem_device *nvmem = cell->nvmem;
+	int rc;
+	void *wbuf = buf;

+
+	if (!nvmem || !nvmem->regmap || nvmem->read_only ||
+	    (cell->bit_offset == 0 && len != cell->bytes))
+		return -EINVAL;
+
+	if (cell->bit_offset || cell->nbits) {
+		wbuf = nvmem_cell_prepare_write_buffer(cell, buf, len);
+		if (IS_ERR(wbuf))
+			return PTR_ERR(wbuf);
+	}
+
+	rc = regmap_raw_write(nvmem->regmap, cell->offset, wbuf, cell->bytes);
+
+	/* free the tmp buffer */
+	if (cell->bit_offset)
+		kfree(wbuf);
+
+	if (IS_ERR_VALUE(rc))
+		return rc;
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_write);