1 files changed, 45 insertions, 1 deletions

diff --git a/drivers/input/matrix-keymap.c b/drivers/input/matrix-keymap.c
index 443ad64b7f2..08b61f506db 100644
--- a/drivers/input/matrix-keymap.c
+++ b/drivers/input/matrix-keymap.c
@@ -18,11 +18,13 @@
  */
 
 #include <linux/device.h>
+#include <linux/gfp.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/input.h>
 #include <linux/of.h>
 #include <linux/export.h>
+#include <linux/module.h>
 #include <linux/input/matrix_keypad.h>
 
 static bool matrix_keypad_map_key(struct input_dev *input_dev,
@@ -48,6 +50,26 @@ static bool matrix_keypad_map_key(struct input_dev *input_dev,
 }
 
 #ifdef CONFIG_OF
+int matrix_keypad_parse_of_params(struct device *dev,
+				  unsigned int *rows, unsigned int *cols)
+{
+	struct device_node *np = dev->of_node;
+
+	if (!np) {
+		dev_err(dev, "missing DT data");
+		return -EINVAL;
+	}
+	of_property_read_u32(np, "keypad,num-rows", rows);
+	of_property_read_u32(np, "keypad,num-columns", cols);
+	if (!*rows || !*cols) {
+		dev_err(dev, "number of keypad rows/columns not specified\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(matrix_keypad_parse_of_params);
+
 static int matrix_keypad_parse_of_keymap(const char *propname,
 					 unsigned int rows, unsigned int cols,
 					 struct input_dev *input_dev)
@@ -122,6 +144,11 @@ static int matrix_keypad_parse_of_keymap(const char *propname,
  * it will attempt load the keymap from property specified by @keymap_name
  * argument (or "linux,keymap" if @keymap_name is %NULL).
  *
+ * If @keymap is %NULL the function will automatically allocate managed
+ * block of memory to store the keymap. This memory will be associated with
+ * the parent device and automatically freed when device unbinds from the
+ * driver.
+ *
  * Callers are expected to set up input_dev->dev.parent before calling this
  * function.
  */
@@ -132,12 +159,27 @@ int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
 			       struct input_dev *input_dev)
 {
 	unsigned int row_shift = get_count_order(cols);
+	size_t max_keys = rows << row_shift;
 	int i;
 	int error;
 
+	if (WARN_ON(!input_dev->dev.parent))
+		return -EINVAL;
+
+	if (!keymap) {
+		keymap = devm_kzalloc(input_dev->dev.parent,
+				      max_keys * sizeof(*keymap),
+				      GFP_KERNEL);
+		if (!keymap) {
+			dev_err(input_dev->dev.parent,
+				"Unable to allocate memory for keymap");
+			return -ENOMEM;
+		}
+	}
+
 	input_dev->keycode = keymap;
 	input_dev->keycodesize = sizeof(*keymap);
-	input_dev->keycodemax = rows << row_shift;
+	input_dev->keycodemax = max_keys;
 
 	__set_bit(EV_KEY, input_dev->evbit);
 
@@ -161,3 +203,5 @@ int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
 	return 0;
 }
 EXPORT_SYMBOL(matrix_keypad_build_keymap);
+
+MODULE_LICENSE("GPL");