When enabling a PWM, allow the existing clock rate and source to stand unchanged.
Signed-off-by: Simon Glass sjg@chromium.org ---
arch/arm/cpu/armv7/tegra-common/pwm.c | 5 ++++- arch/arm/include/asm/arch-tegra/pwm.h | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/armv7/tegra-common/pwm.c b/arch/arm/cpu/armv7/tegra-common/pwm.c index 5b88636..06a0f86 100644 --- a/arch/arm/cpu/armv7/tegra-common/pwm.c +++ b/arch/arm/cpu/armv7/tegra-common/pwm.c @@ -24,7 +24,10 @@ void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider) assert(channel < PWM_NUM_CHANNELS);
/* TODO: Can we use clock_adjust_periph_pll_div() here? */ - clock_start_periph_pll(PERIPH_ID_PWM, CLOCK_ID_SFROM32KHZ, rate); + if (rate) { + clock_start_periph_pll(PERIPH_ID_PWM, CLOCK_ID_SFROM32KHZ, + rate); + }
reg = PWM_ENABLE_MASK; reg |= pulse_width << PWM_WIDTH_SHIFT; diff --git a/arch/arm/include/asm/arch-tegra/pwm.h b/arch/arm/include/asm/arch-tegra/pwm.h index 8e7397d..92dced4 100644 --- a/arch/arm/include/asm/arch-tegra/pwm.h +++ b/arch/arm/include/asm/arch-tegra/pwm.h @@ -31,7 +31,7 @@ struct pwm_ctlr { * Program the PWM with the given parameters. * * @param channel PWM channel to update - * @param rate Clock rate to use for PWM + * @param rate Clock rate to use for PWM, or 0 to leave alone * @param pulse_width high pulse width: 0=always low, 1=1/256 pulse high, * n = n/256 pulse high * @param freq_divider frequency divider value (1 to use rate as is)