summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/pwm/pwm-omap-dmtimer.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index e4f5f710bfaa..92aac6c86b95 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -10,7 +10,15 @@
*
* Description:
* This file is the core OMAP support for the generic, Linux
- * PWM driver / controller, using the OMAP's dual-mode timers.
+ * PWM driver / controller, using the OMAP's dual-mode timers
+ * with a timer counter that goes up. When it overflows it gets
+ * reloaded with the load value and the pwm output goes up.
+ * When counter matches with match register, the output goes down.
+ * Reference Manual: http://www.ti.com/lit/ug/spruh73q/spruh73q.pdf
+ *
+ * Limitations:
+ * - When PWM is stopped, timer counter gets stopped immediately. This
+ * doesn't allow the current PWM period to complete and stops abruptly.
*/
#include <linux/clk.h>