diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-pwm | 9 | ||||
| -rw-r--r-- | drivers/pwm/sysfs.c | 17 |
2 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-pwm b/Documentation/ABI/testing/sysfs-class-pwm index c479d77..c20e613 100644 --- a/Documentation/ABI/testing/sysfs-class-pwm +++ b/Documentation/ABI/testing/sysfs-class-pwm @@ -77,3 +77,12 @@ Description: 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. diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index d985992..c3b1b56 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, "%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); |