[tip: timers/clocksource] clocksource/drivers/samsung_pwm: Switch to raw_spinlock_t type

The following commit has been merged into the timers/clocksource branch of tip:

Commit-ID:     3b212f9d70805d91febae01d618868f4860e267c
Gitweb:        https://git.kernel.org/tip/3b212f9d70805d91febae01d618868f4860e267c
Author:        Marek Szyprowski <[email protected]>
AuthorDate:    Mon, 13 Jul 2026 10:56:53 +02:00
Committer:     Daniel Lezcano <[email protected]>
CommitterDate: Thu, 13 Aug 2026 18:13:15 +02:00

clocksource/drivers/samsung_pwm: Switch to raw_spinlock_t type

Samsung PWM timer might be used as a clock source on some legacy systems.
When PREEMPT_RT is enabled on ARM, regular spinlock is converted to a
sleeping lock (mutex-based), which must not be used in atomic context
such as hard interrupt handlers. Switch the samsung_pwm_lock to the
raw_spinlock, which remains a true non-sleeping spinlock even
under PREEMPT_RT.

Fixes: 7aac482e6290 ("clocksource: samsung_pwm_timer: Make PWM spinlock global")
Fixes: f11899894c0a ("clocksource: add samsung pwm timer driver")
Signed-off-by: Marek Szyprowski <[email protected]>
Signed-off-by: Daniel Lezcano <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Uwe Kleine-König <[email protected]>
Link: https://patch.msgid.link/[email protected]
---
 drivers/clocksource/samsung_pwm_timer.c | 22 +++++++++++-----------
 drivers/pwm/pwm-samsung.c               | 22 +++++++++++-----------
 include/clocksource/samsung_pwm.h       |  2 +-
 3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
index b9561e3..0544124 100644
--- a/drivers/clocksource/samsung_pwm_timer.c
+++ b/drivers/clocksource/samsung_pwm_timer.c
@@ -56,7 +56,7 @@
 #define TCON_AUTORELOAD(chan)		\
 	((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))
 
-DEFINE_SPINLOCK(samsung_pwm_lock);
+DEFINE_RAW_SPINLOCK(samsung_pwm_lock);
 EXPORT_SYMBOL(samsung_pwm_lock);
 
 struct samsung_pwm_clocksource {
@@ -87,14 +87,14 @@ static void samsung_timer_set_prescale(unsigned int channel, u16 prescale)
 	if (channel >= 2)
 		shift = TCFG0_PRESCALER1_SHIFT;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	reg = readl(pwm.base + REG_TCFG0);
 	reg &= ~(TCFG0_PRESCALER_MASK << shift);
 	reg |= (prescale - 1) << shift;
 	writel(reg, pwm.base + REG_TCFG0);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static void samsung_timer_set_divisor(unsigned int channel, u8 divisor)
@@ -106,14 +106,14 @@ static void samsung_timer_set_divisor(unsigned int channel, u8 divisor)
 
 	bits = (fls(divisor) - 1) - pwm.variant.div_base;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	reg = readl(pwm.base + REG_TCFG1);
 	reg &= ~(TCFG1_MUX_MASK << shift);
 	reg |= bits << shift;
 	writel(reg, pwm.base + REG_TCFG1);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static void samsung_time_stop(unsigned int channel)
@@ -124,13 +124,13 @@ static void samsung_time_stop(unsigned int channel)
 	if (channel > 0)
 		++channel;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl_relaxed(pwm.base + REG_TCON);
 	tcon &= ~TCON_START(channel);
 	writel_relaxed(tcon, pwm.base + REG_TCON);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
@@ -142,7 +142,7 @@ static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
 	if (tcon_chan > 0)
 		++tcon_chan;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl_relaxed(pwm.base + REG_TCON);
 
@@ -153,7 +153,7 @@ static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
 	writel_relaxed(tcnt, pwm.base + REG_TCMPB(channel));
 	writel_relaxed(tcon, pwm.base + REG_TCON);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static void samsung_time_start(unsigned int channel, bool periodic)
@@ -164,7 +164,7 @@ static void samsung_time_start(unsigned int channel, bool periodic)
 	if (channel > 0)
 		++channel;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl_relaxed(pwm.base + REG_TCON);
 
@@ -178,7 +178,7 @@ static void samsung_time_start(unsigned int channel, bool periodic)
 
 	writel_relaxed(tcon, pwm.base + REG_TCON);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static int samsung_set_next_event(unsigned long cycles,
diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
index 951b38f..14fb460 100644
--- a/drivers/pwm/pwm-samsung.c
+++ b/drivers/pwm/pwm-samsung.c
@@ -102,7 +102,7 @@ struct samsung_pwm_chip {
  * IP. Should this change, both drivers will need to be modified to
  * properly synchronize accesses to particular instances.
  */
-static DEFINE_SPINLOCK(samsung_pwm_lock);
+static DEFINE_RAW_SPINLOCK(samsung_pwm_lock);
 #endif
 
 static inline
@@ -141,14 +141,14 @@ static void pwm_samsung_set_divisor(struct samsung_pwm_chip *our_chip,
 
 	bits = (fls(divisor) - 1) - our_chip->variant.div_base;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	reg = readl(our_chip->base + REG_TCFG1);
 	reg &= ~(TCFG1_MUX_MASK << shift);
 	reg |= bits << shift;
 	writel(reg, our_chip->base + REG_TCFG1);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static int pwm_samsung_is_tdiv(struct samsung_pwm_chip *our_chip, unsigned int chan)
@@ -249,7 +249,7 @@ static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	unsigned long flags;
 	u32 tcon;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl(our_chip->base + REG_TCON);
 
@@ -263,7 +263,7 @@ static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	our_chip->disabled_mask &= ~BIT(pwm->hwpwm);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 
 	return 0;
 }
@@ -275,7 +275,7 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	unsigned long flags;
 	u32 tcon;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl(our_chip->base + REG_TCON);
 	tcon &= ~TCON_AUTORELOAD(tcon_chan);
@@ -290,7 +290,7 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	our_chip->disabled_mask |= BIT(pwm->hwpwm);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static void pwm_samsung_manual_update(struct samsung_pwm_chip *our_chip,
@@ -298,11 +298,11 @@ static void pwm_samsung_manual_update(struct samsung_pwm_chip *our_chip,
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	__pwm_samsung_manual_update(our_chip, pwm);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static int __pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -390,7 +390,7 @@ static void pwm_samsung_set_invert(struct samsung_pwm_chip *our_chip,
 	unsigned long flags;
 	u32 tcon;
 
-	spin_lock_irqsave(&samsung_pwm_lock, flags);
+	raw_spin_lock_irqsave(&samsung_pwm_lock, flags);
 
 	tcon = readl(our_chip->base + REG_TCON);
 
@@ -404,7 +404,7 @@ static void pwm_samsung_set_invert(struct samsung_pwm_chip *our_chip,
 
 	writel(tcon, our_chip->base + REG_TCON);
 
-	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+	raw_spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
 static int pwm_samsung_set_polarity(struct pwm_chip *chip,
diff --git a/include/clocksource/samsung_pwm.h b/include/clocksource/samsung_pwm.h
index 9b435ca..36f6f24 100644
--- a/include/clocksource/samsung_pwm.h
+++ b/include/clocksource/samsung_pwm.h
@@ -15,7 +15,7 @@
  * spinlock is not shared between both drivers.
  */
 #ifdef CONFIG_CLKSRC_SAMSUNG_PWM
-extern spinlock_t samsung_pwm_lock;
+extern raw_spinlock_t samsung_pwm_lock;
 #endif
 
 struct samsung_pwm_variant {