[PATCH v2] cap11xx: add LED support

[Matt Ranostay <mranostay@gmail.com>]

Several cap11xx variants have LEDs that be can be controlled, this
patchset implements this functionality.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 drivers/input/keyboard/cap11xx.c | 90 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 87 insertions(+), 3 deletions(-)

diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
index f07461a..af1daa0 100644
--- a/drivers/input/keyboard/cap11xx.c
+++ b/drivers/input/keyboard/cap11xx.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/input.h>
+#include <linux/leds.h>
 #include <linux/of_irq.h>
 #include <linux/regmap.h>
 #include <linux/i2c.h>
@@ -47,6 +48,8 @@
 #define CAP11XX_REG_CONFIG2		0x44
 #define CAP11XX_REG_CONFIG2_ALT_POL	BIT(6)
 #define CAP11XX_REG_SENSOR_BASE_CNT(X)	(0x50 + (X))
+#define CAP11XX_REG_LED_POLARITY	0x73
+#define CAP11XX_REG_LED_OUTPUT_CONTROL	0x74
 #define CAP11XX_REG_SENSOR_CALIB	(0xb1 + (X))
 #define CAP11XX_REG_SENSOR_CALIB_LSB1	0xb9
 #define CAP11XX_REG_SENSOR_CALIB_LSB2	0xba
@@ -56,10 +59,25 @@
 
 #define CAP11XX_MANUFACTURER_ID	0x5d
 
+#ifdef CONFIG_LEDS_CLASS
+struct cap11xx_led {
+	struct cap11xx_priv *priv;
+	struct led_classdev cdev;
+	struct work_struct work;
+	char name[32];
+	int id;
+	enum led_brightness new_brightness;
+};
+#endif
+
 struct cap11xx_priv {
 	struct regmap *regmap;
 	struct input_dev *idev;
 
+#ifdef CONFIG_LEDS_CLASS
+	struct cap11xx_led *leds;
+	int num_leds;
+#endif
 	/* config */
 	u32 keycodes[];
 };
@@ -67,6 +85,7 @@ struct cap11xx_priv {
 struct cap11xx_hw_model {
 	u8 product_id;
 	unsigned int num_channels;
+	unsigned int num_leds;
 };
 
 enum {
@@ -76,9 +95,9 @@ enum {
 };
 
 static const struct cap11xx_hw_model cap11xx_devices[] = {
-	[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
-	[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
-	[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
+	[CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
+	[CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
+	[CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
 };
 
 static const struct reg_default cap11xx_reg_defaults[] = {
@@ -111,6 +130,7 @@ static const struct reg_default cap11xx_reg_defaults[] = {
 	{ CAP11XX_REG_STANDBY_SENSITIVITY,	0x02 },
 	{ CAP11XX_REG_STANDBY_THRESH,		0x40 },
 	{ CAP11XX_REG_CONFIG2,			0x40 },
+	{ CAP11XX_REG_LED_POLARITY,		0x00 },
 	{ CAP11XX_REG_SENSOR_CALIB_LSB1,	0x00 },
 	{ CAP11XX_REG_SENSOR_CALIB_LSB2,	0x00 },
 };
@@ -196,6 +216,58 @@ static void cap11xx_input_close(struct input_dev *idev)
 	cap11xx_set_sleep(priv, true);
 }
 
+#ifdef CONFIG_LEDS_CLASS
+static void cap11xx_led_work(struct work_struct *work)
+{
+	struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
+	struct cap11xx_priv *priv = led->priv;
+	int value = led->new_brightness;
+
+	regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
+				BIT(led->id), !!value ? BIT(led->id) : 0);
+}
+
+static void cap11xx_led_set(struct led_classdev *cdev,
+			   enum led_brightness value)
+{
+	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
+
+	led->new_brightness = value;
+	schedule_work(&led->work);
+}
+
+static int cap11xx_register_leds(struct device *dev, struct cap11xx_priv *priv)
+{
+	int ret;
+	int i;
+
+	/*
+	 * Be sure all LEDS are in off-state
+	 */
+	regmap_update_bits(priv->regmap,
+			CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
+
+	for (i = 0; i < priv->num_leds; i++) {
+		struct cap11xx_led *led = &priv->leds[i];
+
+		snprintf(led->name, sizeof(led->name), "cap11xx:led%d", i + 1);
+		led->cdev.name = led->name;
+		led->cdev.brightness_set = cap11xx_led_set;
+		led->cdev.brightness = LED_OFF;
+		led->cdev.max_brightness = 1;
+		led->id = i;
+		led->priv = priv;
+
+		ret = devm_led_classdev_register(dev, &led->cdev);
+		if (ret < 0)
+			return ret;
+
+		INIT_WORK(&led->work, cap11xx_led_work);
+	};
+	return 0;
+}
+#endif
+
 static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 			     const struct i2c_device_id *id)
 {
@@ -316,6 +388,18 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 	priv->idev->open = cap11xx_input_open;
 	priv->idev->close = cap11xx_input_close;
 
+#ifdef CONFIG_LEDS_CLASS
+	if (cap->num_leds > 0) {
+		priv->leds = devm_kcalloc(dev, cap->num_leds,
+				sizeof(struct cap11xx_led), GFP_KERNEL);
+		if (!priv->leds)
+			return -ENOMEM;
+		priv->num_leds = cap->num_leds;
+		error = cap11xx_register_leds(dev, priv);
+		if (error)
+			return error;
+	}
+#endif
 	input_set_drvdata(priv->idev, priv);
 
 	/*
-- 
1.9.1