From: Ben Dooks <ben.dooks@sifive.com>
To: linux-pwm@vger.kernel.org
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Lee Jones <lee.jones@linaro.org>,
u.kleine-koenig@pengutronix.de,
Thierry Reding <thierry.reding@gmail.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Greentime Hu <greentime.hu@sifive.com>,
jarkko.nikula@linux.intel.com,
William Salmon <william.salmon@sifive.com>,
Jude Onyenegecha <jude.onyenegecha@sifive.com>,
Ben Dooks <ben.dooks@sifive.com>
Subject: [RFC v4 10/10] pwm: dwc: add PWM bit unset in get_state call
Date: Tue, 16 Aug 2022 22:14:54 +0100 [thread overview]
Message-ID: <20220816211454.237751-11-ben.dooks@sifive.com> (raw)
In-Reply-To: <20220816211454.237751-1-ben.dooks@sifive.com>
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>
---
v4:
- fixed review comment on mulit-line calculations
---
drivers/pwm/pwm-dwc.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 1251620ab771..5ef0fe7ea3e9 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -121,23 +121,30 @@ 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 + 1) * dwc->clk_ns;
+ period = (ld2 + 1) * 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
next prev parent reply other threads:[~2022-08-16 21:15 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 21:14 [RFC v4 00/10] RFC on synpsys pwm driver changes Ben Dooks
2022-08-16 21:14 ` [RFC v4 01/10] dt-bindings: pwm: Document Synopsys DesignWare snps,pwm-dw-apb-timers-pwm2 Ben Dooks
2022-08-17 5:58 ` Krzysztof Kozlowski
2022-08-18 13:43 ` Ben Dooks
2022-08-18 14:05 ` Krzysztof Kozlowski
2022-08-16 21:14 ` [RFC v4 02/10] pwm: dwc: allow driver to be built with COMPILE_TEST Ben Dooks
2022-09-14 16:11 ` Uwe Kleine-König
2022-09-30 15:47 ` Uwe Kleine-König
2022-08-16 21:14 ` [RFC v4 03/10] pwm: dwc: change &pci->dev to dev in probe Ben Dooks
2022-08-16 21:14 ` [RFC v4 04/10] pwm: dwc: move memory alloc to own function Ben Dooks
2022-08-16 21:14 ` [RFC v4 05/10] pwm: dwc: use devm_pwmchip_add Ben Dooks
2022-09-14 16:14 ` Uwe Kleine-König
2022-08-16 21:14 ` [RFC v4 06/10] pwm: dwc: split pci out of core driver Ben Dooks
2022-08-19 13:38 ` Jarkko Nikula
2022-08-19 16:56 ` Ben Dooks
2022-08-16 21:14 ` [RFC v4 07/10] pwm: dwc: make timer clock configurable Ben Dooks
2022-09-14 16:17 ` Uwe Kleine-König
2022-08-16 21:14 ` [RFC v4 08/10] pwm: dwc: add of/platform support Ben Dooks
2022-09-14 16:47 ` Uwe Kleine-König
2022-09-19 22:30 ` Ben Dooks
2022-09-15 7:24 ` Uwe Kleine-König
2022-09-19 22:06 ` Ben Dooks
2022-08-16 21:14 ` [RFC v4 09/10] pwm: dwc: add snps,pwm-number to limit pwm count Ben Dooks
2022-09-14 16:54 ` Uwe Kleine-König
2022-08-16 21:14 ` Ben Dooks [this message]
2022-09-27 16:47 ` [RFC v4 00/10] RFC on synpsys pwm driver changes Uwe Kleine-König
2022-09-27 18:43 ` Ben Dooks
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