pwm: sysfs: Add PWM capture support

		Enable/disable the PWM signal.

		0 is disabled

		1 is enabled

What:		/sys/class/pwm/pwmchipN/pwmX/capture

Date:		June 2016

KernelVersion:	4.8

Contact:	Lee Jones <lee.jones@linaro.org>

Description:

		Capture information about a PWM signal. The output format is a

		pair unsigned integers (period and duty cycle), separated by a

		single space.

	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, "%u %u\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);