From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: thierry.reding@gmail.com
Cc: u.kleine-koenig@pengutronix.de, lee.jones@linaro.org,
nsaenzjulienne@suse.de, f.fainelli@gmail.com, rjui@broadcom.com,
sbranden@broadcom.com, bcm-kernel-feedback-list@broadcom.com,
linux-pwm@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Lino Sanfilippo <LinoSanfilippo@gmx.de>
Subject: [PATCH v2] pwm: bcm2835: Support apply function for atomic configuration
Date: Sat, 28 Nov 2020 13:02:06 +0100 [thread overview]
Message-ID: <1606564926-19555-1-git-send-email-LinoSanfilippo@gmx.de> (raw)
In-Reply-To: <202011281128.54eLfMWr-lkp@intel.com>
Use the newer apply function of pwm_ops instead of config, enable, disable
and set_polarity.
This guarantees atomic changes of the pwm controller configuration. It also
reduces the size of the driver.
This has been tested on a Raspberry PI 4.
v2: Fixed compiler error
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
drivers/pwm/pwm-bcm2835.c | 64 ++++++++++++++++-------------------------------
1 file changed, 21 insertions(+), 43 deletions(-)
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index 6841dcf..dad7443 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -58,13 +58,14 @@ static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
writel(value, pc->base + PWM_CONTROL);
}
-static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
{
+
struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
unsigned long rate = clk_get_rate(pc->clk);
unsigned long scaler;
- u32 period;
+ u32 value;
if (!rate) {
dev_err(pc->dev, "failed to get clock rate\n");
@@ -72,65 +73,42 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
}
scaler = DIV_ROUND_CLOSEST(NSEC_PER_SEC, rate);
- period = DIV_ROUND_CLOSEST(period_ns, scaler);
+ /* set period */
+ value = DIV_ROUND_CLOSEST_ULL(state->period, scaler);
- if (period < PERIOD_MIN)
+ if (value < PERIOD_MIN)
return -EINVAL;
- writel(DIV_ROUND_CLOSEST(duty_ns, scaler),
- pc->base + DUTY(pwm->hwpwm));
- writel(period, pc->base + PERIOD(pwm->hwpwm));
-
- return 0;
-}
+ writel(value, pc->base + PERIOD(pwm->hwpwm));
-static int bcm2835_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
- u32 value;
+ /* set duty cycle */
+ value = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, scaler);
+ writel(value, pc->base + DUTY(pwm->hwpwm));
+ /* set polarity */
value = readl(pc->base + PWM_CONTROL);
- value |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm);
- writel(value, pc->base + PWM_CONTROL);
-
- return 0;
-}
-static void bcm2835_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
- u32 value;
-
- value = readl(pc->base + PWM_CONTROL);
- value &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm));
- writel(value, pc->base + PWM_CONTROL);
-}
-
-static int bcm2835_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
- enum pwm_polarity polarity)
-{
- struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
- u32 value;
-
- value = readl(pc->base + PWM_CONTROL);
-
- if (polarity == PWM_POLARITY_NORMAL)
+ if (state->polarity == PWM_POLARITY_NORMAL)
value &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm));
else
value |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm);
+ /* enable/disable */
+ if (state->enabled)
+ value |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm);
+ else
+ value &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm));
+
writel(value, pc->base + PWM_CONTROL);
return 0;
}
+
static const struct pwm_ops bcm2835_pwm_ops = {
.request = bcm2835_pwm_request,
.free = bcm2835_pwm_free,
- .config = bcm2835_pwm_config,
- .enable = bcm2835_pwm_enable,
- .disable = bcm2835_pwm_disable,
- .set_polarity = bcm2835_set_polarity,
+ .apply = bcm2835_pwm_apply,
.owner = THIS_MODULE,
};
--
2.7.4
next parent reply other threads:[~2020-11-28 22:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <202011281128.54eLfMWr-lkp@intel.com>
2020-11-28 12:02 ` Lino Sanfilippo [this message]
2020-11-29 18:10 ` [PATCH v2] pwm: bcm2835: Support apply function for atomic configuration Uwe Kleine-König
2020-12-03 23:42 ` Lino Sanfilippo
2020-12-04 8:44 ` Sean Young
2020-12-04 8:58 ` Sean Young
2020-12-04 11:13 ` Uwe Kleine-König
2020-12-04 11:38 ` Sean Young
2020-12-04 23:28 ` Uwe Kleine-König
2020-12-05 17:34 ` Sean Young
2020-12-05 19:25 ` Uwe Kleine-König
2020-12-06 14:19 ` Sean Young
2020-12-07 8:16 ` Uwe Kleine-König
2020-12-07 9:43 ` Sean Young
2020-12-07 13:52 ` Uwe Kleine-König
2020-12-07 15:29 ` Thierry Reding
2020-12-07 21:46 ` Uwe Kleine-König
2020-12-07 18:18 ` Sean Young
2020-12-08 0:00 ` Lino Sanfilippo
2020-12-08 9:07 ` Uwe Kleine-König
2020-12-04 23:16 ` Lino Sanfilippo
2020-12-04 11:21 ` Uwe Kleine-König
2020-12-04 11:40 ` Sean Young
2020-12-04 21:55 ` Uwe Kleine-König
2020-12-04 22:44 ` Sean Young
2020-12-04 23:25 ` Lino Sanfilippo
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