On 11/23/2012 10:34 AM, Alexandre Pereira da Silva wrote: > On Wed, Nov 14, 2012 at 9:58 AM, Alban Bedel > <alban.be...@avionic-design.de> wrote: >> The duty cycles value goes from 1 (99% HIGH) to 256 (0% HIGH) but it >> is stored modulo 256 in the register as it is only 8 bits wide. >> >> Signed-off-by: Alban Bedel <alban.be...@avionic-design.de> > > Acked-by: Alexandre Pereira da Silva <aletes....@gmail.com>
When the below doc typos are fixed, Acked-by: Roland Stigge <sti...@antcom.de> > >> --- >> drivers/pwm/pwm-lpc32xx.c | 17 ++++++++++++++++- >> 1 files changed, 16 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c >> index adb87f0..03ec3ff 100644 >> --- a/drivers/pwm/pwm-lpc32xx.c >> +++ b/drivers/pwm/pwm-lpc32xx.c >> @@ -49,9 +49,24 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, >> struct pwm_device *pwm, >> c = 0; /* 0 set division by 256 */ >> period_cycles = c; >> >> + /* The duty value is a follow: >> + * >> + * DUTY HIGH LEVEL >> + * 1 99.9% >> + * 25 90.0% >> + * 128 50.0% >> + * 220 10.0% >> + * 255 0.1% >> + * 0 0.0% >> + * >> + * In other word the in-register value is duty % 256 with duty >> + * in the range 1-256. >> + */ >> c = 256 * duty_ns; >> do_div(c, period_ns); >> - duty_cycles = c; >> + if (c > 255) >> + c = 255; >> + duty_cycles = 256 - c; >> >> writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | >> PWM_DUTY(duty_cycles), >> lpc32xx->base + (pwm->hwpwm << 2)); >> -- >> 1.7.0.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
