input: samsung-keypad: Add device tree support

Add device tree based discovery support for Samsung's keypad controller.

Cc: Joonyoung Shim <[e-mail]>
Cc: Donghwa Lee <[e-mail]>
Signed-off-by: Thomas Abraham <[e-mail]>
Acked-by: Grant Likely <[e-mail]>
Signed-off-by: Kukjin Kim <[e-mail]>

Documentation/devicetree/bindings/input/samsung-keypad.txt

···
+* Samsung's Keypad Controller device tree bindings
+
+Samsung's Keypad controller is used to interface a SoC with a matrix-type
+keypad device. The keypad controller supports multiple row and column lines.
+A key can be placed at each intersection of a unique row and a unique column.
+The keypad controller can sense a key-press and key-release and report the
+event using a interrupt to the cpu.
+
+Required SoC Specific Properties:
+- compatible: should be one of the following
+  - "samsung,s3c6410-keypad": For controllers compatible with s3c6410 keypad
+    controller.
+  - "samsung,s5pv210-keypad": For controllers compatible with s5pv210 keypad
+    controller.
+
+- reg: physical base address of the controller and length of memory mapped
+  region.
+
+- interrupts: The interrupt number to the cpu.
+
+Required Board Specific Properties:
+- samsung,keypad-num-rows: Number of row lines connected to the keypad
+  controller.
+
+- samsung,keypad-num-columns: Number of column lines connected to the
+  keypad controller.
+
+- row-gpios: List of gpios used as row lines. The gpio specifier for
+  this property depends on the gpio controller to which these row lines
+  are connected.
+
+- col-gpios: List of gpios used as column lines. The gpio specifier for
+  this property depends on the gpio controller to which these column
+  lines are connected.
+
+- Keys represented as child nodes: Each key connected to the keypad
+  controller is represented as a child node to the keypad controller
+  device node and should include the following properties.
+  - keypad,row: the row number to which the key is connected.
+  - keypad,column: the column number to which the key is connected.
+  - linux,code: the key-code to be reported when the key is pressed
+    and released.
+
+Optional Properties specific to linux:
+- linux,keypad-no-autorepeat: do no enable autorepeat feature.
+- linux,keypad-wakeup: use any event on keypad as wakeup event.
+
+
+Example:
+	keypad@100A0000 {
+		compatible = "samsung,s5pv210-keypad";
+		reg = <0x100A0000 0x100>;
+		interrupts = <173>;
+		samsung,keypad-num-rows = <2>;
+		samsung,keypad-num-columns = <8>;
+		linux,input-no-autorepeat;
+		linux,input-wakeup;
+
+		row-gpios = <&gpx2 0 3 3 0
+			     &gpx2 1 3 3 0>;
+
+		col-gpios = <&gpx1 0 3 0 0
+			     &gpx1 1 3 0 0
+			     &gpx1 2 3 0 0
+			     &gpx1 3 3 0 0
+			     &gpx1 4 3 0 0
+			     &gpx1 5 3 0 0
+			     &gpx1 6 3 0 0
+			     &gpx1 7 3 0 0>;
+
+		key_1 {
+			keypad,row = <0>;
+			keypad,column = <3>;
+			linux,code = <2>;
+		};
+
+		key_2 {
+			keypad,row = <0>;
+			keypad,column = <4>;
+			linux,code = <3>;
+		};
+
+		key_3 {
+			keypad,row = <0>;
+			keypad,column = <5>;
+			linux,code = <4>;
+		};
+	};

drivers/input/keyboard/samsung-keypad.c

···
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/sched.h>
 #include <plat/keypad.h>
 
···
 	wait_queue_head_t wait;
 	bool stopped;
 	int irq;
+	enum samsung_keypad_type type;
 	unsigned int row_shift;
 	unsigned int rows;
 	unsigned int cols;
 	unsigned int row_state[SAMSUNG_MAX_COLS];
+#ifdef CONFIG_OF
+	int row_gpios[SAMSUNG_MAX_ROWS];
+	int col_gpios[SAMSUNG_MAX_COLS];
+#endif
 	unsigned short keycodes[];
 };
-
-static int samsung_keypad_is_s5pv210(struct device *dev)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	enum samsung_keypad_type type =
-		platform_get_device_id(pdev)->driver_data;
-
-	return type == KEYPAD_TYPE_S5PV210;
-}
 
 static void samsung_keypad_scan(struct samsung_keypad *keypad,
 				unsigned int *row_state)
 {
-	struct device *dev = keypad->input_dev->dev.parent;
 	unsigned int col;
 	unsigned int val;
 
 	for (col = 0; col < keypad->cols; col++) {
-		if (samsung_keypad_is_s5pv210(dev)) {
+		if (keypad->type == KEYPAD_TYPE_S5PV210) {
 			val = S5PV210_KEYIFCOLEN_MASK;
 			val &= ~(1 << col) << 8;
 		} else {
···
 	samsung_keypad_stop(keypad);
 }
 
+#ifdef CONFIG_OF
+static struct samsung_keypad_platdata *samsung_keypad_parse_dt(
+				struct device *dev)
+{
+	struct samsung_keypad_platdata *pdata;
+	struct matrix_keymap_data *keymap_data;
+	uint32_t *keymap, num_rows = 0, num_cols = 0;
+	struct device_node *np = dev->of_node, *key_np;
+	unsigned int key_count = 0;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(dev, "could not allocate memory for platform data\n");
+		return NULL;
+	}
+
+	of_property_read_u32(np, "samsung,keypad-num-rows", &num_rows);
+	of_property_read_u32(np, "samsung,keypad-num-columns", &num_cols);
+	if (!num_rows || !num_cols) {
+		dev_err(dev, "number of keypad rows/columns not specified\n");
+		return NULL;
+	}
+	pdata->rows = num_rows;
+	pdata->cols = num_cols;
+
+	keymap_data = devm_kzalloc(dev, sizeof(*keymap_data), GFP_KERNEL);
+	if (!keymap_data) {
+		dev_err(dev, "could not allocate memory for keymap data\n");
+		return NULL;
+	}
+	pdata->keymap_data = keymap_data;
+
+	for_each_child_of_node(np, key_np)
+		key_count++;
+
+	keymap_data->keymap_size = key_count;
+	keymap = devm_kzalloc(dev, sizeof(uint32_t) * key_count, GFP_KERNEL);
+	if (!keymap) {
+		dev_err(dev, "could not allocate memory for keymap\n");
+		return NULL;
+	}
+	keymap_data->keymap = keymap;
+
+	for_each_child_of_node(np, key_np) {
+		u32 row, col, key_code;
+		of_property_read_u32(key_np, "keypad,row", &row);
+		of_property_read_u32(key_np, "keypad,column", &col);
+		of_property_read_u32(key_np, "linux,code", &key_code);
+		*keymap++ = KEY(row, col, key_code);
+	}
+
+	if (of_get_property(np, "linux,input-no-autorepeat", NULL))
+		pdata->no_autorepeat = true;
+	if (of_get_property(np, "linux,input-wakeup", NULL))
+		pdata->wakeup = true;
+
+	return pdata;
+}
+
+static void samsung_keypad_parse_dt_gpio(struct device *dev,
+				struct samsung_keypad *keypad)
+{
+	struct device_node *np = dev->of_node;
+	int gpio, ret, row, col;
+
+	for (row = 0; row < keypad->rows; row++) {
+		gpio = of_get_named_gpio(np, "row-gpios", row);
+		keypad->row_gpios[row] = gpio;
+		if (!gpio_is_valid(gpio)) {
+			dev_err(dev, "keypad row[%d]: invalid gpio %d\n",
+					row, gpio);
+			continue;
+		}
+
+		ret = gpio_request(gpio, "keypad-row");
+		if (ret)
+			dev_err(dev, "keypad row[%d] gpio request failed\n",
+					row);
+	}
+
+	for (col = 0; col < keypad->cols; col++) {
+		gpio = of_get_named_gpio(np, "col-gpios", col);
+		keypad->col_gpios[col] = gpio;
+		if (!gpio_is_valid(gpio)) {
+			dev_err(dev, "keypad column[%d]: invalid gpio %d\n",
+					col, gpio);
+			continue;
+		}
+
+		ret = gpio_request(gpio, "keypad-col");
+		if (ret)
+			dev_err(dev, "keypad column[%d] gpio request failed\n",
+					col);
+	}
+}
+
+static void samsung_keypad_dt_gpio_free(struct samsung_keypad *keypad)
+{
+	int cnt;
+
+	for (cnt = 0; cnt < keypad->rows; cnt++)
+		if (gpio_is_valid(keypad->row_gpios[cnt]))
+			gpio_free(keypad->row_gpios[cnt]);
+
+	for (cnt = 0; cnt < keypad->cols; cnt++)
+		if (gpio_is_valid(keypad->col_gpios[cnt]))
+			gpio_free(keypad->col_gpios[cnt]);
+}
+#else
+static
+struct samsung_keypad_platdata *samsung_keypad_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+
+static void samsung_keypad_dt_gpio_free(struct samsung_keypad *keypad)
+{
+}
+#endif
+
 static int __devinit samsung_keypad_probe(struct platform_device *pdev)
 {
 	const struct samsung_keypad_platdata *pdata;
···
 	unsigned int keymap_size;
 	int error;
 
-	pdata = pdev->dev.platform_data;
+	if (pdev->dev.of_node)
+		pdata = samsung_keypad_parse_dt(&pdev->dev);
+	else
+		pdata = pdev->dev.platform_data;
 	if (!pdata) {
 		dev_err(&pdev->dev, "no platform data defined\n");
 		return -EINVAL;
···
 	keypad->cols = pdata->cols;
 	init_waitqueue_head(&keypad->wait);
 
+	if (pdev->dev.of_node) {
+#ifdef CONFIG_OF
+		samsung_keypad_parse_dt_gpio(&pdev->dev, keypad);
+		keypad->type = of_device_is_compatible(pdev->dev.of_node,
+					"samsung,s5pv210-keypad");
+#endif
+	} else {
+		keypad->type = platform_get_device_id(pdev)->driver_data;
+	}
+
 	input_dev->name = pdev->name;
 	input_dev->id.bustype = BUS_HOST;
 	input_dev->dev.parent = &pdev->dev;
···
 
 	device_init_wakeup(&pdev->dev, pdata->wakeup);
 	platform_set_drvdata(pdev, keypad);
+
+	if (pdev->dev.of_node) {
+		devm_kfree(&pdev->dev, (void *)pdata->keymap_data->keymap);
+		devm_kfree(&pdev->dev, (void *)pdata->keymap_data);
+		devm_kfree(&pdev->dev, (void *)pdata);
+	}
 	return 0;
 
 err_free_irq:
 	free_irq(keypad->irq, keypad);
 err_put_clk:
 	clk_put(keypad->clk);
+	samsung_keypad_dt_gpio_free(keypad);
 err_unmap_base:
 	iounmap(keypad->base);
 err_free_mem:
···
 	free_irq(keypad->irq, keypad);
 
 	clk_put(keypad->clk);
+	samsung_keypad_dt_gpio_free(keypad);
 
 	iounmap(keypad->base);
 	kfree(keypad);
···
 };
 #endif
 
+#ifdef CONFIG_OF
+static const struct of_device_id samsung_keypad_dt_match[] = {
+	{ .compatible = "samsung,s3c6410-keypad" },
+	{ .compatible = "samsung,s5pv210-keypad" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, samsung_keypad_dt_match);
+#else
+#define samsung_keypad_dt_match NULL
+#endif
+
 static struct platform_device_id samsung_keypad_driver_ids[] = {
 	{
 		.name		= "samsung-keypad",
···
 	.driver		= {
 		.name	= "samsung-keypad",
 		.owner	= THIS_MODULE,
+		.of_match_table = samsung_keypad_dt_match,
 #ifdef CONFIG_PM
 		.pm	= &samsung_keypad_pm_ops,
 #endif