2023-04-13 21:33:37

by Uwe Kleine-König

[permalink] [raw]
Subject: [PATCH v2] counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe

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 <[email protected]
Signed-off-by: Uwe Kleine-König <[email protected]>
---
Changes since (implicit) v1 sent with Message-Id:
[email protected] .

- 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


2023-04-17 21:42:29

by William Breathitt Gray

[permalink] [raw]
Subject: Re: [PATCH v2] counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe

On Thu, Apr 13, 2023 at 11:23:39PM +0200, Uwe Kleine-K?nig wrote:
> 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 <[email protected]
> Signed-off-by: Uwe Kleine-K?nig <[email protected]>

Applied to the counter-next branch of the Counter tree. I made a minor
fix to Fabrice's Reviewed-by tag line for the missing closing chevron.

Thanks,

William Breathitt Gray


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