diff options
| author | Axel Lin <axel.lin@ingics.com> | 2013-04-23 14:01:31 +0800 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@avionic-design.de> | 2013-04-23 10:58:35 +0200 |
| commit | 08ee77b5a5de27ad63c92262ebcb4efe0da93b58 (patch) | |
| tree | 53a9b7ed0369ca015923b638457ceba14edce926 | |
| parent | f1a8870aeb5baeb58f0613d1f1e1dca967127fbd (diff) | |
| download | linux-08ee77b5a5de27ad63c92262ebcb4efe0da93b58.tar.bz2 | |
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.pdf
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
| -rw-r--r-- | drivers/pwm/pwm-lpc32xx.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c index b55cc5c1d614..6b6272f61da5 100644 --- a/drivers/pwm/pwm-lpc32xx.c +++ b/drivers/pwm/pwm-lpc32xx.c @@ -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) { 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) { 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); } |