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authorThierry Reding <thierry.reding@gmail.com>2016-07-25 16:23:39 +0200
committerThierry Reding <thierry.reding@gmail.com>2016-07-25 16:23:39 +0200
commitbd2686122d3b45db1398776921bd47fedfd6d6a5 (patch)
treea4c9e124eefb9da5434e39f628ee732a597d30c5 /drivers/pwm
parent489babeae6b9386af25fe6dc3bc727a51ff5d962 (diff)
parent1a366fe9153f445e950a7a344932b7419aa83094 (diff)
downloadlinux-bd2686122d3b45db1398776921bd47fedfd6d6a5.tar.gz
Merge branch 'for-4.8/capture' into for-next
Diffstat (limited to 'drivers/pwm')
-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);