1 files changed, 99 insertions, 1 deletions

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 177f5bf27c6d..bca671ff4e54 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -682,7 +682,9 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
 
 	for_each_child_of_node(parent, child) {
 		addr = of_get_property(child, "reg", &len);
-		if (!addr || (len < 2 * sizeof(u32))) {
+		if (!addr)
+			continue;
+		if (len < 2 * sizeof(u32)) {
 			dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
 			return -EINVAL;
 		}
@@ -713,6 +715,7 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
 				cell->name, nvmem->stride);
 			/* Cells already added will be freed later. */
 			kfree_const(cell->name);
+			of_node_put(cell->np);
 			kfree(cell);
 			return -EINVAL;
 		}
@@ -1603,6 +1606,101 @@ int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val)
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_read_u64);
 
+static void *nvmem_cell_read_variable_common(struct device *dev,
+					     const char *cell_id,
+					     size_t max_len, size_t *len)
+{
+	struct nvmem_cell *cell;
+	int nbits;
+	void *buf;
+
+	cell = nvmem_cell_get(dev, cell_id);
+	if (IS_ERR(cell))
+		return cell;
+
+	nbits = cell->nbits;
+	buf = nvmem_cell_read(cell, len);
+	nvmem_cell_put(cell);
+	if (IS_ERR(buf))
+		return buf;
+
+	/*
+	 * If nbits is set then nvmem_cell_read() can significantly exaggerate
+	 * the length of the real data. Throw away the extra junk.
+	 */
+	if (nbits)
+		*len = DIV_ROUND_UP(nbits, 8);
+
+	if (*len > max_len) {
+		kfree(buf);
+		return ERR_PTR(-ERANGE);
+	}
+
+	return buf;
+}
+
+/**
+ * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number.
+ *
+ * @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_variable_le_u32(struct device *dev, const char *cell_id,
+				    u32 *val)
+{
+	size_t len;
+	u8 *buf;
+	int i;
+
+	buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	/* Copy w/ implicit endian conversion */
+	*val = 0;
+	for (i = 0; i < len; i++)
+		*val |= buf[i] << (8 * i);
+
+	kfree(buf);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32);
+
+/**
+ * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number.
+ *
+ * @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_variable_le_u64(struct device *dev, const char *cell_id,
+				    u64 *val)
+{
+	size_t len;
+	u8 *buf;
+	int i;
+
+	buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	/* Copy w/ implicit endian conversion */
+	*val = 0;
+	for (i = 0; i < len; i++)
+		*val |= (uint64_t)buf[i] << (8 * i);
+
+	kfree(buf);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64);
+
 /**
  * nvmem_device_cell_read() - Read a given nvmem device and cell
  *