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From: "David Rivshin (Allworx)" <drivshin.allworx@gmail.com>
To: linux-pwm@vger.kernel.org,
	Thierry Reding <thierry.reding@gmail.com>,
	Neil Armstrong <narmstrong@baylibre.com>
Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	Tony Lindgren <tony@atomide.com>,
	Grant Erickson <marathon96@gmail.com>, NeilBrown <neilb@suse.de>,
	Joachim Eastwood <manabian@gmail.com>
Subject: [PATCH 4/4] pwm: omap-dmtimer: add dev_dbg() message for effective period and duty cycle
Date: Fri, 29 Jan 2016 23:26:54 -0500	[thread overview]
Message-ID: <1454128014-22866-5-git-send-email-drivshin.allworx@gmail.com> (raw)
In-Reply-To: <1454128014-22866-1-git-send-email-drivshin.allworx@gmail.com>

From: David Rivshin <drivshin@allworx.com>

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>
---

I found this helpful while testing the other changes, so I included it in
case it may be of use to someone in the future. I would have no issues with
dropping this if it's not considered worthwhile.

 drivers/pwm/pwm-omap-dmtimer.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 8c9953c..44e3dca 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: %dns, period: %dns\n",
+		duty_ns, period_ns);
 
 	mutex_lock(&omap->mutex);
 	if (duty_ns == pwm_get_duty_cycle(pwm) &&
@@ -163,6 +164,12 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 		duty_cycles = period_cycles - 1;
 	}
 
+	dev_dbg(chip->dev, "effective duty cycle: %lldns, period: %lldns\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;
 
-- 
2.5.0

  parent reply	other threads:[~2016-01-30  4:26 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-30  4:26 [PATCH 0/4] pwm: omap-dmtimer: fix period/duty_cycle calculation David Rivshin (Allworx)
2016-01-30  4:26 ` [PATCH 1/4] pwm: omap-dmtimer: fix inaccurate " David Rivshin (Allworx)
2016-02-03 10:23   ` Neil Armstrong
2016-02-15 20:24     ` Adam Ford
2016-03-04 15:17   ` Thierry Reding
2016-01-30  4:26 ` [PATCH 2/4] pwm: omap-dmtimer: add sanity checking for load and match values David Rivshin (Allworx)
2016-02-01 18:35   ` David Rivshin (Allworx)
2016-02-03 10:24     ` Neil Armstrong
2016-01-30  4:26 ` [PATCH 3/4] pwm: omap-dmtimer: round load and match values rather than truncate David Rivshin (Allworx)
2016-02-03 10:24   ` Neil Armstrong
2016-03-04 15:18   ` Thierry Reding
2016-01-30  4:26 ` David Rivshin (Allworx) [this message]
2016-01-30 14:51   ` [PATCH 4/4] pwm: omap-dmtimer: add dev_dbg() message for effective period and duty cycle Neil Armstrong
2016-02-01 18:22     ` David Rivshin (Allworx)
2016-02-01 18:59       ` Tony Lindgren
2016-02-02 16:23         ` Thierry Reding
2016-02-02 23:44           ` David Rivshin (Allworx)
2016-02-03 14:14             ` Thierry Reding
2016-02-05 19:51               ` David Rivshin (Allworx)
2016-02-09 12:49                 ` Neil Armstrong
2016-01-30 14:52 ` [PATCH 0/4] pwm: omap-dmtimer: fix period/duty_cycle calculation Neil Armstrong
2016-02-01 20:14   ` David Rivshin (Allworx)
2016-02-27  1:31 ` David Rivshin (Allworx)
2016-03-04 15:19   ` Thierry Reding
2016-03-04 16:27     ` David Rivshin (Allworx)
     [not found]       ` <CAHCN7xJYi8VCe8ue_QuYmqTEo-8GPSPiwzM2F_631mMUrwajSA@mail.gmail.com>
2016-03-04 20:01         ` David Rivshin (Allworx)
2016-03-04 20:03           ` Adam Ford
2016-03-04 21:18       ` Thierry Reding
2016-03-04 23:20         ` David Rivshin (Allworx)
2016-03-08 23:23           ` Adam Ford

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