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@xxxxxxxxxxxxxxx>
---
v9:
- fixed multi-line comment
- put authour back to codethink email from sifive
v8:
- fixed rename issues
v4:
- fixed review comment on mulit-line calculations
---
drivers/pwm/pwm-dwc-core.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/drivers/pwm/pwm-dwc-core.c b/drivers/pwm/pwm-dwc-core.c
index 4b4b7b9e1d82..3fc281a78c9a 100644
--- a/drivers/pwm/pwm-dwc-core.c
+++ b/drivers/pwm/pwm-dwc-core.c
@@ -122,24 +122,32 @@ static int 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 + 1) * dwc->clk_ns;
+ period = (ld2 + 1) * dwc->clk_ns;
+ period += duty;
+ } else {
+ duty = (ld + 1) * dwc->clk_ns;
+ period = duty * 2;
+ }
state->polarity = PWM_POLARITY_INVERSED;
+ state->period = period;
+ state->duty_cycle = duty;
pm_runtime_put_sync(chip->dev);
--
2.40.1
