linux-kernel - [PATCH] feat(kernel/pca963x): implement power management

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Message-ID: <881c6ba1-1701-41be-a4ac-81cdca5f0eea@gmail.com>
Date:   Sun, 10 Dec 2023 17:16:52 +0530
From:   Amitesh Singh <singh.amitesh@...il.com>
To:     Pavel Machek <pavel@....cz>
Cc:     Lee Jones <lee@...nel.org>, linux-leds@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] feat(kernel/pca963x): implement power management

 From a22dbd7390ce875e81d67f14f05f593d7f03d5c1 Mon Sep 17 00:00:00 2001
From: Amitesh Singh <singh.amitesh@...il.com>
Date: Fri, 8 Dec 2023 15:08:33 +0530
Subject: [PATCH] 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

Signed-off-by: Amitesh Singh <singh.amitesh@...il.com>
---
  drivers/leds/leds-pca963x.c | 41 +++++++++++++++++++++++++++++++++++++
  1 file changed, 41 insertions(+)

diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 47223c850e4b..462f917dc986 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/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 */
@@ -380,6 +381,45 @@ static int pca963x_register_leds(struct i2c_client 
*client,
  	return ret;
  }

+#ifdef CONFIG_PM
+static int pca963x_suspend(struct device *dev)
+{
+	struct pca963x *chip;
+	u8 reg;
+
+	chip = dev_get_drvdata(dev);
+
+	reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
+	reg = reg | (1 << PCA963X_MODE1_SLEEP);
+	i2c_smbus_write_byte_data(chip->client, PCA963X_MODE1, reg);
+
+	return 0;
+}
+
+static int pca963x_resume(struct device *dev)
+{
+	struct pca963x *chip;
+	u8 reg;
+
+	chip = dev_get_drvdata(dev);
+
+	reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
+	reg = reg & ~(1 << PCA963X_MODE1_SLEEP);
+	i2c_smbus_write_byte_data(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", },
@@ -430,6 +470,7 @@ 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,
-- 
2.43.0