pwm: fix min and max duty cycle

PD#165774: pwm: fix min and max duty cycle

When the duty equal 0% and 100%, there is one high or low
count ,the constant bit should be enabled;and constant
bit should be disabled for other duty_cycle.

Change-Id: I36eefee3613f113f6c30db076e41cd8223086c54
Signed-off-by: Jian Hu <jian.hu@amlogic.com>

diff --git a/drivers/amlogic/pwm/pwm_meson.c b/drivers/amlogic/pwm/pwm_meson.c
index e7b1b1d..22853df 100644 (file)
--- a/drivers/amlogic/pwm/pwm_meson.c
+++ b/drivers/amlogic/pwm/pwm_meson.c
@@ -204,12 +204,12 @@ static int meson_pwm_calc(struct meson_pwm *meson,
 
        if (duty == period) {
                channel->pre_div = pre_div;
-               channel->hi = cnt - 1;
+               channel->hi = cnt;
                channel->lo = 0;
        } else if (duty == 0) {
                channel->pre_div = pre_div;
                channel->hi = 0;
-               channel->lo = cnt - 1;
+               channel->lo = cnt;
        } else {
                /* Then check is we can have the duty with the same pre_div */
                duty_cnt = DIV_ROUND_CLOSEST_ULL((u64)duty * 1000,
@@ -226,6 +226,16 @@ static int meson_pwm_calc(struct meson_pwm *meson,
                channel->hi = duty_cnt - 1;
                channel->lo = cnt - duty_cnt - 1;
        }
+       /*
+        * duty_cycle equal 0% and 100%,constant should be enabled,
+        * high and low count will not incease one;
+        * otherwise, high and low count increase one.
+        */
+       if (duty == period || duty == 0)
+               pwm_constant_enable(meson, id);
+       else
+               pwm_constant_disable(meson, id);
+
 
        return 0;
 }