Commit 08ee77b5 authored by Axel Lin's avatar Axel Lin Committed by Thierry Reding

pwm: lpc32xx: Properly set PWM_ENABLE bit in lpc32xx_pwm_[enable|disable]

According to the LPC32x0 User Manual [1]:

For both PWM1 and PWM2 Control Registers:
BIT 31:
This bit gates the PWM_CLK signal and enables the external output pin
to the PWM_PIN_STATE logical level.

0 = PWM disabled. (Default)
1 = PWM enabled

So in lpc32xx_pwm_enable(), we should set PWM_ENABLE bit.
In lpc32xx_pwm_disable(), we should just clear PWM_ENABLE bit rather than
write 0 to the register which will also clear PWMx_RELOADV and PWMx_DUTY bits.

[1] http://www.nxp.com/documents/user_manual/UM10326.pdfSigned-off-by: default avatarAxel Lin <axel.lin@ingics.com>
Tested-by: default avatarRoland Stigge <stigge@antcom.de>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent f1a8870a
...@@ -77,15 +77,29 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, ...@@ -77,15 +77,29 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{ {
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
u32 val;
int ret;
ret = clk_enable(lpc32xx->clk);
if (ret)
return ret;
return clk_enable(lpc32xx->clk); val = readl(lpc32xx->base + (pwm->hwpwm << 2));
val |= PWM_ENABLE;
writel(val, lpc32xx->base + (pwm->hwpwm << 2));
return 0;
} }
static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{ {
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
u32 val;
val = readl(lpc32xx->base + (pwm->hwpwm << 2));
val &= ~PWM_ENABLE;
writel(val, lpc32xx->base + (pwm->hwpwm << 2));
writel(0, lpc32xx->base + (pwm->hwpwm << 2));
clk_disable(lpc32xx->clk); clk_disable(lpc32xx->clk);
} }
......
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