linux-kernel - [PATCH 2/3] leds: pca9532: Explicitly disable hardware blink when PWM1 is unavailable

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Date: Mon, 27 May 2024 14:59:39 +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@...tlin.com,
	christophercordahi@...ometrics.ca,
	Bastien Curutchet <bastien.curutchet@...tlin.com>
Subject: [PATCH 2/3] leds: pca9532: Explicitly disable hardware blink when PWM1 is unavailable

When a led is used to driver 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
driver beepers.

Signed-off-by: Bastien Curutchet <bastien.curutchet@...tlin.com>
---
 drivers/leds/leds-pca9532.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index c210608ad336..356b71a4b7ac 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -47,6 +47,7 @@ struct pca9532_data {
 	const struct pca9532_chip_info *chip_info;
 	u8 pwm[2];
 	u8 psc[2];
+	bool hw_blink;
 };
 
 static int pca9532_probe(struct i2c_client *client);
@@ -234,6 +235,9 @@ static int pca9532_set_blink(struct led_classdev *led_cdev,
 	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;
@@ -390,6 +394,7 @@ 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];
@@ -424,6 +429,8 @@ 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);
-- 
2.44.0