Releasing ctrl_lock for the duration of the delay is not desirable as it
allows re-enabling the PWM before the delay is over. Instead, substitute
the spinlock with a mutex so that we can sleep while holding it.
Signed-off-by: Roman Beranek <roman.bera...@prusa3d.com>
---
drivers/pwm/pwm-sun4i.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 2777abe66f79..b3ec59a83d00 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -16,13 +16,13 @@
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/reset.h>
#include <linux/slab.h>
-#include <linux/spinlock.h>
#include <linux/time.h>
#define PWM_CTRL_REG 0x0
@@ -87,7 +87,7 @@ struct sun4i_pwm_chip {
struct clk *clk;
struct reset_control *rst;
void __iomem *base;
- spinlock_t ctrl_lock;
+ struct mutex ctrl_lock;
const struct sun4i_pwm_data *data;
unsigned long next_period[2];
};
@@ -265,7 +265,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct
pwm_device *pwm,
return ret;
}
- spin_lock(&sun4i_pwm->ctrl_lock);
+ mutex_lock(&sun4i_pwm->ctrl_lock);
ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
if (sun4i_pwm->data->has_direct_mod_clk_output) {
@@ -273,7 +273,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct
pwm_device *pwm,
ctrl |= BIT_CH(PWM_BYPASS, pwm->hwpwm);
/* We can skip other parameter */
sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
- spin_unlock(&sun4i_pwm->ctrl_lock);
+ mutex_unlock(&sun4i_pwm->ctrl_lock);
return 0;
}
@@ -308,10 +308,10 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct
pwm_device *pwm,
sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
- spin_unlock(&sun4i_pwm->ctrl_lock);
-
- if (state->enabled)
+ if (state->enabled) {
+ mutex_unlock(&sun4i_pwm->ctrl_lock);
return 0;
+ }
/* We need a full period to elapse before disabling the channel. */
now = jiffies;
@@ -324,11 +324,9 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct
pwm_device *pwm,
usleep_range(delay_us, delay_us * 2);
}
- spin_lock(&sun4i_pwm->ctrl_lock);
- ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
- spin_unlock(&sun4i_pwm->ctrl_lock);
+ mutex_unlock(&sun4i_pwm->ctrl_lock);
clk_disable_unprepare(sun4i_pwm->clk);
@@ -471,7 +469,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
pwm->chip.of_xlate = of_pwm_xlate_with_flags;
pwm->chip.of_pwm_n_cells = 3;
- spin_lock_init(&pwm->ctrl_lock);
+ mutex_init(&pwm->ctrl_lock);
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
--
2.31.1
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