From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org, kernel@pengutronix.de
Subject: [PATCH] pwm: omap-dmtimer: Drop locking
Date: Tue, 5 Dec 2023 10:56:17 +0100 [thread overview]
Message-ID: <20231205095617.1412865-2-u.kleine-koenig@pengutronix.de> (raw)
The pwm driver only provides a single PWM line, so there are no concurrent
calls of the callbacks from different consumers. A single consumer is
expected not to do concurrent calls into the pwm framework. So there is
nothing to serialize and the lock can go away.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-omap-dmtimer.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 13161e08dd6e..496bd73d29fe 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -37,7 +37,6 @@
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <clocksource/timer-ti-dm.h>
@@ -55,7 +54,6 @@
* struct pwm_omap_dmtimer_chip - Structure representing a pwm chip
* corresponding to omap dmtimer.
* @chip: PWM chip structure representing PWM controller
- * @mutex: Mutex to protect pwm apply state
* @dm_timer: Pointer to omap dm timer.
* @pdata: Pointer to omap dm timer ops.
* @dm_timer_pdev: Pointer to omap dm timer platform device
@@ -63,7 +61,6 @@
struct pwm_omap_dmtimer_chip {
struct pwm_chip chip;
/* Mutex to protect pwm apply state */
- struct mutex mutex;
struct omap_dm_timer *dm_timer;
const struct omap_dm_timer_ops *pdata;
struct platform_device *dm_timer_pdev;
@@ -277,13 +274,11 @@ static int pwm_omap_dmtimer_apply(struct pwm_chip *chip,
const struct pwm_state *state)
{
struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
- int ret = 0;
-
- mutex_lock(&omap->mutex);
+ int ret;
if (pwm_omap_dmtimer_is_enabled(omap) && !state->enabled) {
omap->pdata->stop(omap->dm_timer);
- goto unlock_mutex;
+ return 0;
}
if (pwm_omap_dmtimer_polarity(omap) != state->polarity)
@@ -292,7 +287,7 @@ static int pwm_omap_dmtimer_apply(struct pwm_chip *chip,
ret = pwm_omap_dmtimer_config(chip, pwm, state->duty_cycle,
state->period);
if (ret)
- goto unlock_mutex;
+ return ret;
if (!pwm_omap_dmtimer_is_enabled(omap) && state->enabled) {
omap->pdata->set_pwm(omap->dm_timer,
@@ -303,10 +298,7 @@ static int pwm_omap_dmtimer_apply(struct pwm_chip *chip,
pwm_omap_dmtimer_start(omap);
}
-unlock_mutex:
- mutex_unlock(&omap->mutex);
-
- return ret;
+ return 0;
}
static const struct pwm_ops pwm_omap_dmtimer_ops = {
@@ -404,8 +396,6 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
omap->chip.ops = &pwm_omap_dmtimer_ops;
omap->chip.npwm = 1;
- mutex_init(&omap->mutex);
-
ret = pwmchip_add(&omap->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register PWM\n");
@@ -452,8 +442,6 @@ static void pwm_omap_dmtimer_remove(struct platform_device *pdev)
omap->pdata->free(omap->dm_timer);
put_device(&omap->dm_timer_pdev->dev);
-
- mutex_destroy(&omap->mutex);
}
static const struct of_device_id pwm_omap_dmtimer_of_match[] = {
base-commit: aaa69b9d49de73bd5f17b29cb6ce423afc83bcc9
--
2.42.0
reply other threads:[~2023-12-05 9:56 UTC|newest]
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