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Message-ID: <20240711120129.100248-3-bastien.curutchet@bootlin.com>
Date: Thu, 11 Jul 2024 14:01:27 +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 v3 2/4] leds: pca9532: Use PWM1 for hardware blinking
PSC0/PWM0 are used by all LEDs for brightness and blinking. This causes
conflicts when you set a brightness of a new LED while an other one is
already using PWM0 for blinking.
Use PSC1/PWM1 for blinking.
Check that no other LED is already blinking with a different PSC1/PWM1
configuration to avoid conflict.
Signed-off-by: Bastien Curutchet <bastien.curutchet@...tlin.com>
---
drivers/leds/leds-pca9532.c | 52 ++++++++++++++++++++++++++++++-------
1 file changed, 42 insertions(+), 10 deletions(-)
diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index b6e5f48bffe7..098fd66ca43e 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -29,6 +29,9 @@
#define LED_SHIFT(led) (LED_NUM(led) * 2)
#define LED_MASK(led) (0x3 << LED_SHIFT(led))
+#define PCA9532_PWM_PERIOD_DIV 152
+#define PCA9532_PWM_DUTY_DIV 256
+
#define ldev_to_led(c) container_of(c, struct pca9532_led, ldev)
struct pca9532_chip_info {
@@ -194,29 +197,58 @@ static int pca9532_set_brightness(struct led_classdev *led_cdev,
return err;
}
+static int pca9532_update_hw_blink(struct pca9532_led *led,
+ unsigned long delay_on, unsigned long delay_off)
+{
+ struct pca9532_data *data = i2c_get_clientdata(led->client);
+ unsigned int psc;
+ int i;
+
+ /* Look for others LEDs that already use PWM1 */
+ for (i = 0; i < data->chip_info->num_leds; i++) {
+ struct pca9532_led *other = &data->leds[i];
+
+ if (other == led)
+ continue;
+
+ if (other->state == PCA9532_PWM1) {
+ if (other->ldev.blink_delay_on != delay_on ||
+ other->ldev.blink_delay_off != delay_off) {
+ /* HW can handle only one blink configuration at a time */
+ return -EBUSY;
+ }
+ }
+ }
+
+ psc = ((delay_on + delay_off) * PCA9532_PWM_PERIOD_DIV - 1) / 1000;
+ if (psc > U8_MAX) {
+ /* Blink period too long to be handled by hardware */
+ return -EINVAL;
+ }
+
+ led->state = PCA9532_PWM1;
+ data->psc[PCA9532_PWM_ID_1] = psc;
+ data->pwm[PCA9532_PWM_ID_1] = (delay_on * PCA9532_PWM_DUTY_DIV) / (delay_on + delay_off);
+
+ return pca9532_setpwm(data->client, PCA9532_PWM_ID_1);
+}
+
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;
- int psc;
- int err = 0;
+ int err;
if (*delay_on == 0 && *delay_off == 0) {
/* led subsystem ask us for a blink rate */
*delay_on = 1000;
*delay_off = 1000;
}
- if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
- return -EINVAL;
- /* Thecus specific: only use PSC/PWM 0 */
- psc = (*delay_on * 152-1)/1000;
- err = pca9532_calcpwm(client, PCA9532_PWM_ID_0, psc, led_cdev->brightness);
+ err = pca9532_update_hw_blink(led, *delay_on, *delay_off);
if (err)
return err;
- if (led->state == PCA9532_PWM0)
- pca9532_setpwm(led->client, PCA9532_PWM_ID_0);
+
pca9532_setled(led);
return 0;
--
2.45.0
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