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-rw-r--r--drivers/pwm/core.c27
-rw-r--r--drivers/pwm/sysfs.c17
2 files changed, 44 insertions, 0 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index ed337a8c34ab..0dbd29e287db 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -526,6 +526,33 @@ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
EXPORT_SYMBOL_GPL(pwm_apply_state);
/**
+ * pwm_capture() - capture and report a PWM signal
+ * @pwm: PWM device
+ * @result: structure to fill with capture result
+ * @timeout: time to wait, in milliseconds, before giving up on capture
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
+ unsigned long timeout)
+{
+ int err;
+
+ if (!pwm || !pwm->chip->ops)
+ return -EINVAL;
+
+ if (!pwm->chip->ops->capture)
+ return -ENOSYS;
+
+ mutex_lock(&pwm_lock);
+ err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
+ mutex_unlock(&pwm_lock);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(pwm_capture);
+
+/**
* pwm_adjust_config() - adjust the current PWM config to the PWM arguments
* @pwm: PWM device
*
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 01695d48dd54..18ed725594c3 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);