Puts device into DEEP SLEEP when no LEDs are in in the on-state, and no
input_handlers are in use. Also uses *_autosuspend to prevent a LED
trigger from constantly suspending and resuming device.

Signed-off-by: Matt Ranostay <redacted>
---
 drivers/input/keyboard/cap11xx.c | 84 +++++++++++++++++++++++++++++++---------
 1 file changed, 65 insertions(+), 19 deletions(-)

diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
index 378db10..13fae03 100644
--- a/drivers/input/keyboard/cap11xx.c
+++ b/drivers/input/keyboard/cap11xx.c

@@ -14,6 +14,7 @@
 #include <linux/input.h>
 #include <linux/leds.h>
 #include <linux/of_irq.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/i2c.h>
 #include <linux/gpio/consumer.h>

@@ -84,9 +85,9 @@ struct cap11xx_led {
 struct cap11xx_priv {
 	struct regmap *regmap;
 	struct input_dev *idev;
+	struct i2c_client *i2c_client;
 
 	struct cap11xx_led *leds;
-	int num_leds;
 
 	/* config */
 	u32 keycodes[];

@@ -207,12 +208,6 @@ out:
 
 static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
 {
-	/*
-	 * DLSEEP mode will turn off all LEDS, prevent this
-	 */
-	if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
-		return 0;
-
 	return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
 				  CAP11XX_REG_MAIN_CONTROL_DLSEEP,
 				  sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);

@@ -222,14 +217,16 @@ static int cap11xx_input_open(struct input_dev *idev)
 {
 	struct cap11xx_priv *priv = input_get_drvdata(idev);
 
-	return cap11xx_set_sleep(priv, false);
+	pm_runtime_get(&priv->i2c_client->dev);
+
+	return 0;
 }
 
 static void cap11xx_input_close(struct input_dev *idev)
 {
 	struct cap11xx_priv *priv = input_get_drvdata(idev);
 
-	cap11xx_set_sleep(priv, true);
+	pm_runtime_put_autosuspend(&priv->i2c_client->dev);
 }
 
 #ifdef CONFIG_LEDS_CLASS

@@ -251,10 +248,16 @@ static void cap11xx_led_set(struct led_classdev *cdev,
 			   enum led_brightness value)
 {
 	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
+	struct cap11xx_priv *priv = led->priv;
 
 	if (led->new_brightness == value)
 		return;
 
+	if (value)
+		pm_runtime_get(&priv->i2c_client->dev);
+	else
+		pm_runtime_put_autosuspend(&priv->i2c_client->dev);
+

 	led->new_brightness = value;
 	schedule_work(&led->work);
 }

@@ -315,8 +318,6 @@ static int cap11xx_init_leds(struct device *dev,
 		error = devm_led_classdev_register(dev, &led->cdev);
 		if (error)
 			return error;
-
-		priv->num_leds++;
 		led++;
 	}
 

@@ -330,6 +331,16 @@ static int cap11xx_init_leds(struct device *dev,
 }
 #endif
 
+static void cap11xx_shutdown_act(void *data)
+{
+	struct i2c_client *i2c_client = data;
+	struct cap11xx_priv *priv = i2c_get_clientdata(i2c_client);
+
+	cap11xx_set_sleep(priv, true);
+	pm_runtime_disable(&i2c_client->dev);
+	pm_runtime_set_suspended(&i2c_client->dev);
+}
+
 static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 			     const struct i2c_device_id *id)
 {

@@ -363,6 +374,14 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 	if (IS_ERR(priv->regmap))
 		return PTR_ERR(priv->regmap);
 
+	error = devm_add_action(dev, cap11xx_shutdown_act, i2c_client);
+	if (error) {
+		dev_err(dev, "failed to register remove action\n");
+		return error;
+	}
+	i2c_set_clientdata(i2c_client, priv);
+	priv->i2c_client = i2c_client;
+
 	error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
 	if (error)
 		return error;

@@ -388,7 +407,6 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 		return error;
 
 	dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev);
-	i2c_set_clientdata(i2c_client, priv);
 	node = dev->of_node;
 
 	if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {

@@ -450,22 +468,28 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 	priv->idev->open = cap11xx_input_open;
 	priv->idev->close = cap11xx_input_close;
 
-	error = cap11xx_init_leds(dev, priv, cap->num_leds);
+	error = cap11xx_set_sleep(priv, true);
 	if (error)
 		return error;
 
-	input_set_drvdata(priv->idev, priv);
+	error = pm_runtime_set_active(dev);

+	if (error)
+		return error;
 
-	/*
-	 * Put the device in deep sleep mode for now.
-	 * ->open() will bring it back once the it is actually needed.
-	 */
-	cap11xx_set_sleep(priv, true);
+	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_use_autosuspend(dev);
+
+	input_set_drvdata(priv->idev, priv);
 
 	error = input_register_device(priv->idev);
 	if (error)
 		return error;
 
+	error = cap11xx_init_leds(dev, priv, cap->num_leds);
+	if (error)
+		return error;
+
 	irq = irq_of_parse_and_map(node, 0);
 	if (!irq) {
 		dev_err(dev, "Unable to parse or map IRQ\n");

@@ -496,10 +520,32 @@ static const struct i2c_device_id cap11xx_i2c_ids[] = {
 };
 MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
 
+#ifdef CONFIG_PM
+static int cap11xx_runtime_suspend(struct device *dev)