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authorAxel Lin <axel.lin@ingics.com>2013-04-23 14:01:31 +0800
committerThierry Reding <thierry.reding@avionic-design.de>2013-04-23 10:58:35 +0200
commit08ee77b5a5de27ad63c92262ebcb4efe0da93b58 (patch)
tree53a9b7ed0369ca015923b638457ceba14edce926 /drivers/pwm
parentf1a8870aeb5baeb58f0613d1f1e1dca967127fbd (diff)
downloadop-kernel-dev-08ee77b5a5de27ad63c92262ebcb4efe0da93b58.zip
op-kernel-dev-08ee77b5a5de27ad63c92262ebcb4efe0da93b58.tar.gz
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>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-lpc32xx.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index b55cc5c..6b6272f 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);
}
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