feat(kernel/pca963x): implement power management

This implements power management in upstream driver for
pca9633 which enables device sleep and resume on system-wide
sleep/hibernation

drivers/leds/leds-pca963x.c

@@ -39,6 +39,7 @@
 #define PCA963X_LED_PWM		0x2	/* Controlled through PWM */
 #define PCA963X_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */
 
+#define PCA963X_MODE1_SLEEP     0x04    /* Normal mode or Low Power mode, oscillator off */
 #define PCA963X_MODE2_OUTDRV	0x04	/* Open-drain or totem pole */
 #define PCA963X_MODE2_INVRT	0x10	/* Normal or inverted direction */
 #define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */
@@ -362,6 +363,45 @@ static int pca963x_register_leds(struct i2c_client *client,
 	return ret;
 }
 
+#ifdef CONFIG_PM
+static int pca963x_suspend(struct device *dev)
+{
+	struct pca963x_led *led;
+	u8 reg;
+
+	led = dev_get_drvdata(dev);
+
+	reg = i2c_smbus_read_byte_data(led->chip->client, PCA963X_MODE1);
+	reg = reg | (1 << PCA963X_MODE1_SLEEP);
+	i2c_smbus_write_byte_data(led->chip->client, PCA963X_MODE1, reg);
+
+	return 0;
+}
+
+static int pca963x_resume(struct device *dev)
+{
+	struct pca963x_led *led;
+	u8 reg;
+
+	led = dev_get_drvdata(dev);
+
+	reg = i2c_smbus_read_byte_data(led->chip->client, PCA963X_MODE1);
+	reg = reg & ~(1 << PCA963X_MODE1_SLEEP);
+	i2c_smbus_write_byte_data(led->chip->client, PCA963X_MODE1, reg);
+
+	return 0;
+}
+
+static const struct dev_pm_ops pca963x_pmops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pca963x_suspend, pca963x_resume)
+};
+
+#define PCA963X_SMBUS_PMOPS (&pca963x_pmops)
+
+#else
+#define PCA963X_SMBUS_PMOPS NULL
+#endif
+
 static const struct of_device_id of_pca963x_match[] = {
 	{ .compatible = "nxp,pca9632", },
 	{ .compatible = "nxp,pca9633", },
@@ -412,6 +452,7 @@ static struct i2c_driver pca963x_driver = {
 	.driver = {
 		.name	= "leds-pca963x",
 		.of_match_table = of_pca963x_match,
+		.pm = PCA963X_SMBUS_PMOPS
 	},
 	.probe	= pca963x_probe,
 	.id_table = pca963x_id,