[PATCH v2] counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe
From: Uwe Kleine-König
Date: Thu Apr 13 2023 - 17:23:57 EST
The driver assumes that the input selection register (TIM_TISEL) is at
its reset default value. Usually this is the case, but the bootloader
might have modified it.
This bases on a similar patch submitted by Olivier Moysan for pwm-stm32.
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Changes since (implicit) v1 sent with Message-Id:
20230412153709.3557323-1-u.kleine-koenig@xxxxxxxxxxxxxx .
- Only reset TIM_TISEL as suggested by Fabrice
- Add Fabrice's Review tag
drivers/counter/stm32-timer-cnt.c | 3 +++
include/linux/mfd/stm32-timers.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 9bf20a5d6bda..6206d2dc3d47 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -342,6 +342,9 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
+ /* Reset input selector to its default input */
+ regmap_write(priv->regmap, TIM_TISEL, 0x0);
+
/* Register Counter device */
ret = devm_counter_add(dev, counter);
if (ret < 0)
diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h
index 5f5c43fd69dd..1b94325febb3 100644
--- a/include/linux/mfd/stm32-timers.h
+++ b/include/linux/mfd/stm32-timers.h
@@ -31,6 +31,7 @@
#define TIM_BDTR 0x44 /* Break and Dead-Time Reg */
#define TIM_DCR 0x48 /* DMA control register */
#define TIM_DMAR 0x4C /* DMA register for transfer */
+#define TIM_TISEL 0x68 /* Input Selection */
#define TIM_CR1_CEN BIT(0) /* Counter Enable */
#define TIM_CR1_DIR BIT(4) /* Counter Direction */
base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
--
2.39.2