1 files changed, 42 insertions, 4 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 4c49285168fb..d12e5de78e70 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -135,7 +135,7 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
 
 	/* Stop the user from writing */
 	if (pos >= nvmem->size)
-		return 0;
+		return -EFBIG;
 
 	if (count < nvmem->word_size)
 		return -EINVAL;
@@ -290,7 +290,7 @@ static struct nvmem_cell *nvmem_find_cell(const char *cell_id)
 	mutex_lock(&nvmem_cells_mutex);
 
 	list_for_each_entry(p, &nvmem_cells, node)
-		if (p && !strcmp(p->name, cell_id)) {
+		if (!strcmp(p->name, cell_id)) {
 			mutex_unlock(&nvmem_cells_mutex);
 			return p;
 		}
@@ -789,13 +789,14 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
 		return ERR_PTR(-EINVAL);
 
 	nvmem = __nvmem_device_get(nvmem_np, NULL, NULL);
+	of_node_put(nvmem_np);
 	if (IS_ERR(nvmem))
 		return ERR_CAST(nvmem);
 
 	addr = of_get_property(cell_np, "reg", &len);
 	if (!addr || (len < 2 * sizeof(u32))) {
-		dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n",
-			cell_np->full_name);
+		dev_err(&nvmem->dev, "nvmem: invalid reg on %pOF\n",
+			cell_np);
 		rval  = -EINVAL;
 		goto err_mem;
 	}
@@ -1111,6 +1112,43 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
 EXPORT_SYMBOL_GPL(nvmem_cell_write);
 
 /**
+ * nvmem_cell_read_u32() - Read a cell value as an u32
+ *
+ * @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_u32(struct device *dev, const char *cell_id, u32 *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_u32);
+
+/**
  * nvmem_device_cell_read() - Read a given nvmem device and cell
  *
  * @nvmem: nvmem device to read from.