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authorLee Jones <lee.jones@linaro.org>2016-06-08 10:21:23 +0100
committerThierry Reding <thierry.reding@gmail.com>2016-06-10 16:01:35 +0200
commit3a3d1a4e32ab47323d7b8c8b7631a8d36a3098b2 (patch)
treea79165beca06b134c36ac6dd6ebbcd82e36d3206 /drivers/pwm
parent1a695a905c18548062509178b98bc91e67510864 (diff)
pwm: Add PWM capture support
Supply a PWM capture callback op in order to pass back information obtained by running analysis on a PWM signal. This would normally (at least during testing) be called from the sysfs routines with a view to printing out PWM capture data which has been encoded into a string. Signed-off-by: Lee Jones <lee.jones@linaro.org> [thierry.reding@gmail.com: make capture data unsigned int for symmetry] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/core.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index dba3843c53b8..8f40604046d6 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -525,6 +525,33 @@ 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
*