4.14-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Zapolskiy vz@mleia.com
[ 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@linaro.org Signed-off-by: Vladimir Zapolskiy vz@mleia.com Signed-off-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Fixes: 3d2813fb17e5 ("pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered") Signed-off-by: Thierry Reding thierry.reding@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pwm/pwm-lpc32xx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c index ed8e9406b4af2..b5f8b86b328af 100644 --- a/drivers/pwm/pwm-lpc32xx.c +++ b/drivers/pwm/pwm-lpc32xx.c @@ -55,10 +55,10 @@ 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; } @@ -73,9 +73,9 @@ 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; } @@ -85,9 +85,9 @@ 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); } @@ -125,9 +125,9 @@ 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) {