This is a note to let you know that I've just added the patch titled
pwm: lpc32xx: Remove handling of PWM channels
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pwm-lpc32xx-remove-handling-of-pwm-channels.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 283e2a60cf3d29f60a0b160a179b621bb2799e97
Author: Vladimir Zapolskiy <vz@xxxxxxxxx>
Date: Mon Jul 17 17:52:57 2023 +0200
pwm: lpc32xx: Remove handling of PWM channels
[ Upstream commit 4aae44f65827f0213a7361cf9c32cfe06114473f ]
Because LPC32xx PWM controllers have only a single output which is
registered as the only PWM device/channel per controller, it is known in
advance that pwm->hwpwm value is always 0. On basis of this fact
simplify the code by removing operations with pwm->hwpwm, there is no
controls which require channel number as input.
Even though I wasn't aware at the time when I forward ported that patch,
this fixes a null pointer dereference as lpc32xx->chip.pwms is NULL
before devm_pwmchip_add() is called.
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Vladimir Zapolskiy <vz@xxxxxxxxx>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Fixes: 3d2813fb17e5 ("pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered")
Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index 522f862eca526..504a8f506195a 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -51,10 +51,10 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
if (duty_cycles > 255)
duty_cycles = 255;
- val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val = readl(lpc32xx->base);
val &= ~0xFFFF;
val |= (period_cycles << 8) | duty_cycles;
- writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+ writel(val, lpc32xx->base);
return 0;
}
@@ -69,9 +69,9 @@ static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
if (ret)
return ret;
- val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val = readl(lpc32xx->base);
val |= PWM_ENABLE;
- writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+ writel(val, lpc32xx->base);
return 0;
}
@@ -81,9 +81,9 @@ static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
u32 val;
- val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val = readl(lpc32xx->base);
val &= ~PWM_ENABLE;
- writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+ writel(val, lpc32xx->base);
clk_disable_unprepare(lpc32xx->clk);
}
@@ -121,9 +121,9 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
lpc32xx->chip.base = -1;
/* If PWM is disabled, configure the output to the default value */
- val = readl(lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
+ val = readl(lpc32xx->base);
val &= ~PWM_PIN_LEVEL;
- writel(val, lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
+ writel(val, lpc32xx->base);
ret = pwmchip_add(&lpc32xx->chip);
if (ret < 0) {
