On 04/23/2013 08:01 AM, Axel Lin wrote: > 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 <[email protected]>
Tested-by: Roland Stigge <[email protected]> > --- > Hi, > I don't have this hardware handy so I'd appreciate if someone can test this > patch serial. > > This patch serial was sent on https://lkml.org/lkml/2013/3/30/104 > Seems no feedback so far. > So I just try again, maybe someone can help testing it. > Thanks, > Axel > > drivers/pwm/pwm-lpc32xx.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c > index b3f0d0d..1a5075e 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); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
