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[PATCH v3 10/20] pwm: sysfs: Add PWM Capture support

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  [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Lee Jones <lee.jones@linaro.org> - 2016-06-08 11:30 +0200
    Re: [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Thierry Reding <thierry.reding@gmail.com> - 2016-06-10 16:10 +0200
      Re: [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Lee Jones <lee.jones@linaro.org> - 2016-06-10 16:40 +0200

#1417153 — [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support

Allow a user to read PWM Capture results from /sysfs.

To start a capture and read the result, simply read the file:

  $ cat $PWMCHIP/capture

The output format is "<period>:<duty_cycle>".

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/pwm/sysfs.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index d985992..901e647 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -208,16 +208,33 @@ static ssize_t polarity_store(struct device *child,
 	return ret ? : size;
 }
 
+static ssize_t capture_show(struct device *child,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_capture result;
+	int ret;
+
+	ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%llu %llu\n", result.period, result.duty_cycle);
+}
+
 static DEVICE_ATTR_RW(period);
 static DEVICE_ATTR_RW(duty_cycle);
 static DEVICE_ATTR_RW(enable);
 static DEVICE_ATTR_RW(polarity);
+static DEVICE_ATTR_RO(capture);
 
 static struct attribute *pwm_attrs[] = {
 	&dev_attr_period.attr,
 	&dev_attr_duty_cycle.attr,
 	&dev_attr_enable.attr,
 	&dev_attr_polarity.attr,
+	&dev_attr_capture.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(pwm);
-- 
2.8.3

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#1419452

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On Wed, Jun 08, 2016 at 10:21:25AM +0100, Lee Jones wrote:
> Allow a user to read PWM Capture results from /sysfs.
> 
> To start a capture and read the result, simply read the file:
> 
>   $ cat $PWMCHIP/capture
> 
> The output format is "<period>:<duty_cycle>".

The format below is "<period> <duty cycle>".

No need to rev the series for this, I can take patches 8 and 10 as-is
and make those modifications myself.

Thierry

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#1419479

On Fri, 10 Jun 2016, Thierry Reding wrote:

> On Wed, Jun 08, 2016 at 10:21:25AM +0100, Lee Jones wrote:
> > Allow a user to read PWM Capture results from /sysfs.
> > 
> > To start a capture and read the result, simply read the file:
> > 
> >   $ cat $PWMCHIP/capture
> > 
> > The output format is "<period>:<duty_cycle>".
> 
> The format below is "<period> <duty cycle>".
> 
> No need to rev the series for this, I can take patches 8 and 10 as-is
> and make those modifications myself.

Ideal, thanks.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

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