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authorJiri Kosina <jkosina@suse.cz>2014-11-20 14:42:02 +0100
committerJiri Kosina <jkosina@suse.cz>2014-11-20 14:42:02 +0100
commita02001086bbfb4da35d1228bebc2f1b442db455f (patch)
tree62ab47936cef06fd08657ca5b6cd1df98c19be57 /drivers/pwm/pwm-atmel.c
parenteff264efeeb0898408e8c9df72d8a32621035bed (diff)
parentfc14f9c1272f62c3e8d01300f52467c0d9af50f9 (diff)
Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
Diffstat (limited to 'drivers/pwm/pwm-atmel.c')
-rw-r--r--drivers/pwm/pwm-atmel.c24
1 files changed, 11 insertions, 13 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 6e700a541ca..d3c22de9ee4 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -102,7 +102,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
- unsigned long clk_rate, prd, dty;
+ unsigned long prd, dty;
unsigned long long div;
unsigned int pres = 0;
u32 val;
@@ -113,20 +113,18 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return -EBUSY;
}
- clk_rate = clk_get_rate(atmel_pwm->clk);
- div = clk_rate;
+ /* Calculate the period cycles and prescale value */
+ div = (unsigned long long)clk_get_rate(atmel_pwm->clk) * period_ns;
+ do_div(div, NSEC_PER_SEC);
- /* Calculate the period cycles */
while (div > PWM_MAX_PRD) {
- div = clk_rate / (1 << pres);
- div = div * period_ns;
- /* 1/Hz = 100000000 ns */
- do_div(div, 1000000000);
-
- if (pres++ > PRD_MAX_PRES) {
- dev_err(chip->dev, "pres exceeds the maximum value\n");
- return -EINVAL;
- }
+ div >>= 1;
+ pres++;
+ }
+
+ if (pres > PRD_MAX_PRES) {
+ dev_err(chip->dev, "pres exceeds the maximum value\n");
+ return -EINVAL;
}
/* Calculate the duty cycles */