Commit 998d189a authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Thierry Reding
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pwm: atmel: Document known weaknesses of both hardware and software 



This documents the my findings while reading through the driver and the
reference manual.

Signed-off-by: default avatarUwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 2101c878

drivers/pwm/pwm-atmel.c

+10 −0
Original line number Diff line number Diff line
@@ -7,6 +7,16 @@ 
 *

 * Links to reference manuals for the supported PWM chips can be found in

 * Documentation/arm/microchip.rst.

 *

 * Limitations:

 * - Periods start with the inactive level.

 * - Hardware has to be stopped in general to update settings.

 *

 * Software bugs/possible improvements:

 * - When atmel_pwm_apply() is called with state->enabled=false a change in

 *   state->polarity isn't honored.

 * - Instead of sleeping to wait for a completed period, the interrupt

 *   functionality could be used.

 */



#include <linux/clk.h>