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Subject[[PATCH v2] 9/9] pwm: dwc: add PWM bit unset in get_state call
Date
If we are not in PWM mode, then the output is technically a 50%
output based on a single timer instead of the high-low based on
the two counters. Add a check for the PWM mode in dwc_pwm_get_state()
and if DWC_TIM_CTRL_PWM is not set, then return a 50% cycle.

This may only be an issue on initialisation, as the rest of the
code currently assumes we're always going to have the extended
PWM mode using two counters.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
---
drivers/pwm/pwm-dwc.c | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index da325133d297..f3723c4d1e59 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -171,23 +171,35 @@ static void dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
{
struct dwc_pwm *dwc = to_dwc_pwm(chip);
u64 duty, period;
+ u32 ctrl, ld, ld2;

pm_runtime_get_sync(chip->dev);

- state->enabled = !!(dwc_pwm_readl(dwc,
- DWC_TIM_CTRL(pwm->hwpwm)) & DWC_TIM_CTRL_EN);
+ ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm->hwpwm));
+ ld = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
+ ld2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));

- duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
- duty += 1;
- duty *= dwc->clk_ns;
- state->duty_cycle = duty;
+ state->enabled = !!(ctrl & DWC_TIM_CTRL_EN);

- period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
- period += 1;
- period *= dwc->clk_ns;
- period += duty;
- state->period = period;
+ /* If we're not in PWM, technically the output is a 50-50
+ * based on the timer load-count only.
+ */
+ if (ctrl & DWC_TIM_CTRL_PWM) {
+ duty = ld;
+ duty += 1;
+ duty *= dwc->clk_ns;
+
+ period = ld2;
+ period += 1;
+ period *= dwc->clk_ns;
+ period += duty;
+ } else {
+ duty = (ld + 1) * dwc->clk_ns;
+ period = duty * 2;
+ }

+ state->period = period;
+ state->duty_cycle = duty;
state->polarity = PWM_POLARITY_INVERSED;

pm_runtime_put_sync(chip->dev);
--
2.35.1
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