Input: stmpe-keypad - add support for Device Tree bindings

This patch allows the STMPE driver to be successfully probed and
initialised when Device Tree support is enabled. Besides the usual
platform data changes, we also separate the process of filling in
the 'in use' pin bitmap, as we have to extract the information from
Device Tree in the DT boot case.

Acked-by: Arnd Bergmann <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

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

···
+* STMPE Keypad
+
+Required properties:
+ - compatible               : "st,stmpe-keypad"
+ - linux,keymap             : See ./matrix-keymap.txt
+
+Optional properties:
+ - debounce-interval        : Debouncing interval time in milliseconds
+ - st,scan-count            : Scanning cycles elapsed before key data is updated
+ - st,no-autorepeat         : If specified device will not autorepeat
+
+Example:
+
+	stmpe_keypad {
+		compatible = "st,stmpe-keypad";
+
+		debounce-interval = <64>;
+		st,scan-count = <8>;
+		st,no-autorepeat;
+
+		linux,keymap = <0x205006b
+				0x4010074
+				0x3050072
+				0x1030004
+				0x502006a
+				0x500000a
+				0x5008b
+				0x706001c
+				0x405000b
+				0x6070003
+				0x3040067
+				0x303006c
+				0x60400e7
+				0x602009e
+				0x4020073
+				0x5050002
+				0x4030069
+				0x3020008>;
+	};

drivers/input/keyboard/stmpe-keypad.c

···
 			      (plat->debounce_ms << 1));
 }
 
+static void stmpe_keypad_fill_used_pins(struct stmpe_keypad *keypad)
+{
+	int row, col;
+
+	for (row = 0; row < STMPE_KEYPAD_MAX_ROWS; row++) {
+		for (col = 0; col < STMPE_KEYPAD_MAX_COLS; col++) {
+			int code = MATRIX_SCAN_CODE(row, col,
+						STMPE_KEYPAD_ROW_SHIFT);
+			if (keypad->keymap[code] != KEY_RESERVED) {
+				keypad->rows |= 1 << row;
+				keypad->cols |= 1 << col;
+			}
+		}
+	}
+}
+
+#ifdef CONFIG_OF
+static const struct stmpe_keypad_platform_data *
+stmpe_keypad_of_probe(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct stmpe_keypad_platform_data *plat;
+
+	if (!np)
+		return ERR_PTR(-ENODEV);
+
+	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
+	if (!plat)
+		return ERR_PTR(-ENOMEM);
+
+	of_property_read_u32(np, "debounce-interval", &plat->debounce_ms);
+	of_property_read_u32(np, "st,scan-count", &plat->scan_count);
+
+	plat->no_autorepeat = of_property_read_bool(np, "st,no-autorepeat");
+
+	return plat;
+}
+#else
+static inline const struct stmpe_keypad_platform_data *
+stmpe_keypad_of_probe(struct device *dev)
+{
+	return ERR_PTR(-EINVAL);
+}
+#endif
+
 static int stmpe_keypad_probe(struct platform_device *pdev)
 {
 	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
···
 	struct input_dev *input;
 	int error;
 	int irq;
-	int i;
 
 	plat = stmpe->pdata->keypad;
-	if (!plat)
-		return -ENODEV;
+	if (!plat) {
+		plat = stmpe_keypad_of_probe(&pdev->dev);
+		if (IS_ERR(plat))
+			return PTR_ERR(plat);
+	}
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
···
 	if (!plat->no_autorepeat)
 		__set_bit(EV_REP, input->evbit);
 
-	for (i = 0; i < plat->keymap_data->keymap_size; i++) {
-		unsigned int key = plat->keymap_data->keymap[i];
-
-		keypad->cols |= 1 << KEY_COL(key);
-		keypad->rows |= 1 << KEY_ROW(key);
-	}
+	stmpe_keypad_fill_used_pins(keypad);
 
 	keypad->stmpe = stmpe;
 	keypad->plat = plat;

drivers/mfd/stmpe.c

···
 
 static struct mfd_cell stmpe_keypad_cell = {
 	.name		= "stmpe-keypad",
+	.of_compatible  = "st,stmpe-keypad",
 	.resources	= stmpe_keypad_resources,
 	.num_resources	= ARRAY_SIZE(stmpe_keypad_resources),
 };