linux-kernel - [PATCH v2 3/4] leds: pca9532: Explicitly disable hardware blink when PWM1 is unavailable

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Date: Mon, 17 Jun 2024 16:39:09 +0200
From: Bastien Curutchet <bastien.curutchet@...tlin.com>
To: Riku Voipio <riku.voipio@....fi>,
	Pavel Machek <pavel@....cz>,
	Lee Jones <lee@...nel.org>
Cc: linux-leds@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
	Herve Codina <herve.codina@...tlin.com>,
	Christopher Cordahi <christophercordahi@...ometrics.ca>,
	Bastien Curutchet <bastien.curutchet@...tlin.com>
Subject: [PATCH v2 3/4] leds: pca9532: Explicitly disable hardware blink when PWM1 is unavailable

When a LED is used to drive a beeper, it uses PWM1. This can cause
conflicts if an other LED want to use PWM1 for blinking.

Disable use of hardware for blinking when one or more LEDs are used to
drive beepers.

Signed-off-by: Bastien Curutchet <bastien.curutchet@...tlin.com>
---
 drivers/leds/leds-pca9532.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index 244ae3ff79b5..c7a4f677ed4d 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -53,6 +53,7 @@ struct pca9532_data {
 #define PCA9532_PWM_ID_1	1
 	u8 pwm[2];
 	u8 psc[2];
+	bool hw_blink;
 };
 
 static int pca9532_probe(struct i2c_client *client);
@@ -238,8 +239,13 @@ static int pca9532_set_blink(struct led_classdev *led_cdev,
 	unsigned long *delay_on, unsigned long *delay_off)
 {
 	struct pca9532_led *led = ldev_to_led(led_cdev);
+	struct i2c_client *client = led->client;
+	struct pca9532_data *data = i2c_get_clientdata(client);
 	int err;
 
+	if (!data->hw_blink)
+		return -EINVAL;
+
 	if (*delay_on == 0 && *delay_off == 0) {
 		/* led subsystem ask us for a blink rate */
 		*delay_on = 1000;
@@ -395,6 +401,7 @@ static int pca9532_configure(struct i2c_client *client,
 			data->psc[i]);
 	}
 
+	data->hw_blink = true;
 	for (i = 0; i < data->chip_info->num_leds; i++) {
 		struct pca9532_led *led = &data->leds[i];
 		struct pca9532_led *pled = &pdata->leds[i];
@@ -429,6 +436,8 @@ static int pca9532_configure(struct i2c_client *client,
 			pca9532_setled(led);
 			break;
 		case PCA9532_TYPE_N2100_BEEP:
+			/* PWM1 is reserved for beeper so blink will not use hardware */
+			data->hw_blink = false;
 			BUG_ON(data->idev);
 			led->state = PCA9532_PWM1;
 			pca9532_setled(led);
-- 
2.45.0