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authorDavid Rivshin <drivshin@allworx.com>2016-01-30 05:26:54 +0100
committerThierry Reding <thierry.reding@gmail.com>2016-03-23 17:11:48 +0100
commit922201d129c8f9d0c3207dca90ea6ffd8e2242f0 (patch)
tree4911766dccfe46cce732f4ccd434df7372ae8ede /drivers/pwm
parentpwm: omap-dmtimer: Round load and match values rather than truncate (diff)
downloadlinux-922201d129c8f9d0c3207dca90ea6ffd8e2242f0.tar.xz
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pwm: omap-dmtimer: Add debug message for effective period and duty cycle
After going through the math and constraints checking to compute load and match values, it is helpful to know what the resultant period and duty cycle are. Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-omap-dmtimer.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index e0679eb399f6..b7e6ecba7d5c 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -102,7 +102,8 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
unsigned long clk_rate;
bool timer_active;
- dev_dbg(chip->dev, "duty cycle: %d, period %d\n", duty_ns, period_ns);
+ dev_dbg(chip->dev, "requested duty cycle: %d ns, period: %d ns\n",
+ duty_ns, period_ns);
mutex_lock(&omap->mutex);
if (duty_ns == pwm_get_duty_cycle(pwm) &&
@@ -166,6 +167,12 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
duty_cycles = period_cycles - 1;
}
+ dev_dbg(chip->dev, "effective duty cycle: %lld ns, period: %lld ns\n",
+ DIV_ROUND_CLOSEST_ULL((u64)NSEC_PER_SEC * duty_cycles,
+ clk_rate),
+ DIV_ROUND_CLOSEST_ULL((u64)NSEC_PER_SEC * period_cycles,
+ clk_rate));
+
load_value = (DM_TIMER_MAX - period_cycles) + 1;
match_value = load_value + duty_cycles - 1;