Input: matrix_keypad - make matrix keymap size dynamic

Remove assumption on the shift and size of rows/columns form
matrix_keypad driver.

Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
index e9b2e7cb..541b981 100644
--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c
@@ -27,6 +27,7 @@
 	const struct matrix_keypad_platform_data *pdata;
 	struct input_dev *input_dev;
 	unsigned short *keycodes;
+	unsigned int row_shift;
 
 	uint32_t last_key_state[MATRIX_MAX_COLS];
 	struct delayed_work work;
@@ -136,7 +137,7 @@
 			if ((bits_changed & (1 << row)) == 0)
 				continue;
 
-			code = (row << 4) + col;
+			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
 			input_report_key(input_dev,
 					 keypad->keycodes[code],
@@ -317,6 +318,7 @@
 	struct matrix_keypad *keypad;
 	struct input_dev *input_dev;
 	unsigned short *keycodes;
+	unsigned int row_shift;
 	int i;
 	int err;
 
@@ -332,14 +334,11 @@
 		return -EINVAL;
 	}
 
-	if (!keymap_data->max_keymap_size) {
-		dev_err(&pdev->dev, "invalid keymap data supplied\n");
-		return -EINVAL;
-	}
+	row_shift = get_count_order(pdata->num_col_gpios);
 
 	keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
-	keycodes = kzalloc(keymap_data->max_keymap_size *
-				sizeof(keypad->keycodes),
+	keycodes = kzalloc((pdata->num_row_gpios << row_shift) *
+				sizeof(*keycodes),
 			   GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!keypad || !keycodes || !input_dev) {
@@ -350,6 +349,7 @@
 	keypad->input_dev = input_dev;
 	keypad->pdata = pdata;
 	keypad->keycodes = keycodes;
+	keypad->row_shift = row_shift;
 	keypad->stopped = true;
 	INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
 	spin_lock_init(&keypad->lock);
@@ -363,7 +363,7 @@
 
 	input_dev->keycode	= keycodes;
 	input_dev->keycodesize	= sizeof(*keycodes);
-	input_dev->keycodemax	= keymap_data->max_keymap_size;
+	input_dev->keycodemax	= pdata->num_row_gpios << keypad->row_shift;
 
 	for (i = 0; i < keymap_data->keymap_size; i++) {
 		unsigned int key = keymap_data->keymap[i];
@@ -371,7 +371,7 @@
 		unsigned int col = KEY_COL(key);
 		unsigned short code = KEY_VAL(key);
 
-		keycodes[(row << 4) + col] = code;
+		keycodes[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
 		__set_bit(code, input_dev->keybit);
 	}
 	__clear_bit(KEY_RESERVED, input_dev->keybit);
diff --git a/include/linux/input/matrix_keypad.h b/include/linux/input/matrix_keypad.h
index 7964516..15d5903 100644
--- a/include/linux/input/matrix_keypad.h
+++ b/include/linux/input/matrix_keypad.h
@@ -15,12 +15,13 @@
 #define KEY_COL(k)		(((k) >> 16) & 0xff)
 #define KEY_VAL(k)		((k) & 0xffff)
 
+#define MATRIX_SCAN_CODE(row, col, row_shift)	(((row) << (row_shift)) + (col))
+
 /**
  * struct matrix_keymap_data - keymap for matrix keyboards
  * @keymap: pointer to array of uint32 values encoded with KEY() macro
  *	representing keymap
  * @keymap_size: number of entries (initialized) in this keymap
- * @max_keymap_size: maximum size of keymap supported by the device
  *
  * This structure is supposed to be used by platform code to supply
  * keymaps to drivers that implement matrix-like keypads/keyboards.
@@ -28,14 +29,13 @@
 struct matrix_keymap_data {
 	const uint32_t *keymap;
 	unsigned int	keymap_size;
-	unsigned int	max_keymap_size;
 };
 
 /**
  * struct matrix_keypad_platform_data - platform-dependent keypad data
  * @keymap_data: pointer to &matrix_keymap_data
- * @row_gpios: array of gpio numbers reporesenting rows
- * @col_gpios: array of gpio numbers reporesenting colums
+ * @row_gpios: pointer to array of gpio numbers representing rows
+ * @col_gpios: pointer to array of gpio numbers reporesenting colums
  * @num_row_gpios: actual number of row gpios used by device
  * @num_col_gpios: actual number of col gpios used by device
  * @col_scan_delay_us: delay, measured in microseconds, that is
@@ -48,8 +48,9 @@
 struct matrix_keypad_platform_data {
 	const struct matrix_keymap_data *keymap_data;
 
-	unsigned int	row_gpios[MATRIX_MAX_ROWS];
-	unsigned int	col_gpios[MATRIX_MAX_COLS];
+	const unsigned int *row_gpios;
+	const unsigned int *col_gpios;
+
 	unsigned int	num_row_gpios;
 	unsigned int	num_col_gpios;