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From: Stefan Wahren <stefan.wahren@i2se.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Stephen Warren <swarren@wwwdotorg.org>,
	Lee Jones <lee@kernel.org>, Eric Anholt <eric@anholt.net>
Cc: Remi Pommarel <repk@triplefau.lt>,
	linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rpi-kernel@lists.infradead.org,
	Stefan Wahren <stefan.wahren@i2se.com>
Subject: [PATCH 1/3] pwm: bcm2835: calculate scaler in pwm_config
Date: Tue,  1 Dec 2015 22:55:39 +0000	[thread overview]
Message-ID: <1449010541-3767-2-git-send-email-stefan.wahren@i2se.com> (raw)
In-Reply-To: <1449010541-3767-1-git-send-email-stefan.wahren@i2se.com>

Currently pwm-bcm2835 assumes a fixed clock rate and stores the
resulting scaler in the driver structure. But with the upcoming
PWM clock support for clk-bcm2835 the rate could change.
So calculate the scaler in pwm_config.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/pwm/pwm-bcm2835.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index b4c7f95..174cca9 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -29,7 +29,6 @@
 struct bcm2835_pwm {
 	struct pwm_chip chip;
 	struct device *dev;
-	unsigned long scaler;
 	void __iomem *base;
 	struct clk *clk;
 };
@@ -66,6 +65,7 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
 	struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
+	unsigned long scaler = NSEC_PER_SEC / clk_get_rate(pc->clk);
 
 	if (period_ns <= MIN_PERIOD) {
 		dev_err(pc->dev, "period %d not supported, minimum %d\n",
@@ -73,8 +73,8 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return -EINVAL;
 	}
 
-	writel(duty_ns / pc->scaler, pc->base + DUTY(pwm->hwpwm));
-	writel(period_ns / pc->scaler, pc->base + PERIOD(pwm->hwpwm));
+	writel(duty_ns / scaler, pc->base + DUTY(pwm->hwpwm));
+	writel(period_ns / scaler, pc->base + PERIOD(pwm->hwpwm));
 
 	return 0;
 }
@@ -156,8 +156,6 @@ static int bcm2835_pwm_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	pc->scaler = NSEC_PER_SEC / clk_get_rate(pc->clk);
-
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &bcm2835_pwm_ops;
 	pc->chip.npwm = 2;
-- 
1.7.9.5

  reply	other threads:[~2015-12-01 22:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-01 22:55 [PATCH 0/3] pwm: bcm2835: improve clock handling Stefan Wahren
2015-12-01 22:55 ` Stefan Wahren [this message]
2015-12-01 22:55 ` [PATCH 2/3] pwm: bcm2835: prevent division by zero Stefan Wahren
2015-12-01 23:16   ` Eric Anholt
2015-12-02 17:08     ` Stefan Wahren
2015-12-02 19:43       ` Eric Anholt
2015-12-02 15:23   ` Mathieu Poirier
2015-12-02 19:41     ` Eric Anholt
2015-12-01 22:55 ` [PATCH 3/3] pwm: bcm2835: fix email address specifiction Stefan Wahren
2015-12-15 17:59 ` [PATCH 0/3] pwm: bcm2835: improve clock handling Stefan Wahren
2015-12-15 18:24   ` Eric Anholt
2015-12-16 15:38 ` Thierry Reding

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