[PATCH 5/8] pwm: microchip-core: Drop driver local locking
Uwe Kleine-König
u.kleine-koenig at baylibre.com
Tue Jun 24 11:15:41 PDT 2025
The pwm core already serializes .apply() and .get_state(), so the driver
local lock is always free and adds no protection.
Drop it.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig at baylibre.com>
---
drivers/pwm/pwm-microchip-core.c | 17 +----------------
1 file changed, 1 insertion(+), 16 deletions(-)
diff --git a/drivers/pwm/pwm-microchip-core.c b/drivers/pwm/pwm-microchip-core.c
index 12821b4bbf97..4ff32bb4c205 100644
--- a/drivers/pwm/pwm-microchip-core.c
+++ b/drivers/pwm/pwm-microchip-core.c
@@ -36,7 +36,6 @@
#include <linux/ktime.h>
#include <linux/math.h>
#include <linux/module.h>
-#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
@@ -56,7 +55,6 @@
struct mchp_core_pwm_chip {
struct clk *clk;
void __iomem *base;
- struct mutex lock; /* protects the shared period */
ktime_t update_timestamp;
u32 sync_update_mask;
u16 channel_enabled;
@@ -360,17 +358,10 @@ static int mchp_core_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct mchp_core_pwm_chip *mchp_core_pwm = to_mchp_core_pwm(chip);
- int ret;
-
- mutex_lock(&mchp_core_pwm->lock);
mchp_core_pwm_wait_for_sync_update(mchp_core_pwm, pwm->hwpwm);
- ret = mchp_core_pwm_apply_locked(chip, pwm, state);
-
- mutex_unlock(&mchp_core_pwm->lock);
-
- return ret;
+ return mchp_core_pwm_apply_locked(chip, pwm, state);
}
static int mchp_core_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -381,8 +372,6 @@ static int mchp_core_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm
u16 prescale, period_steps;
u8 duty_steps, posedge, negedge;
- mutex_lock(&mchp_core_pwm->lock);
-
mchp_core_pwm_wait_for_sync_update(mchp_core_pwm, pwm->hwpwm);
if (mchp_core_pwm->channel_enabled & (1 << pwm->hwpwm))
@@ -415,8 +404,6 @@ static int mchp_core_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm
posedge = readb_relaxed(mchp_core_pwm->base + MCHPCOREPWM_POSEDGE(pwm->hwpwm));
negedge = readb_relaxed(mchp_core_pwm->base + MCHPCOREPWM_NEGEDGE(pwm->hwpwm));
- mutex_unlock(&mchp_core_pwm->lock);
-
if (negedge == posedge) {
state->duty_cycle = state->period;
state->period *= 2;
@@ -469,8 +456,6 @@ static int mchp_core_pwm_probe(struct platform_device *pdev)
&mchp_core_pwm->sync_update_mask))
mchp_core_pwm->sync_update_mask = 0;
- mutex_init(&mchp_core_pwm->lock);
-
chip->ops = &mchp_core_pwm_ops;
mchp_core_pwm->channel_enabled = readb_relaxed(mchp_core_pwm->base + MCHPCOREPWM_EN(0));
--
2.49.0
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