mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-12-08 23:03:46 +00:00
35 lines
1.2 KiB
Diff
35 lines
1.2 KiB
Diff
From d1eff01309855f850d82e4ce9abe42ad76aa7f9f Mon Sep 17 00:00:00 2001
|
|
From: Yuxi Sun <b36102@freescale.com>
|
|
Date: Thu, 15 Dec 2011 10:12:53 +0800
|
|
Subject: [PATCH] ENGR00170342 PWM: fix pwm output can't be set to 100% full duty
|
|
|
|
The chip document says the counter counts up to period_cycles + 1
|
|
and then is reset to 0, so the actual period of the PWM wave is
|
|
period_cycles + 2
|
|
|
|
Signed-off-by: Yuxi Sun <b36102@freescale.com>
|
|
(cherry picked from commit e1465447502c77b2951af7ace43d8f76fa5039fb)
|
|
---
|
|
arch/arm/plat-mxc/pwm.c | 6 +++++-
|
|
1 files changed, 5 insertions(+), 1 deletions(-)
|
|
|
|
diff --git a/arch/arm/plat-mxc/pwm.c b/arch/arm/plat-mxc/pwm.c
|
|
index 2f8a35e..ccba298 100644
|
|
--- a/arch/arm/plat-mxc/pwm.c
|
|
+++ b/arch/arm/plat-mxc/pwm.c
|
|
@@ -83,7 +83,11 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
|
|
prescale = period_cycles / 0x10000 + 1;
|
|
|
|
period_cycles /= prescale;
|
|
- c = (unsigned long long)period_cycles * duty_ns;
|
|
+ /* the chip document says the counter counts up to
|
|
+ * period_cycles + 1 and then is reset to 0, so the
|
|
+ * actual period of the PWM wave is period_cycles + 2
|
|
+ */
|
|
+ c = (unsigned long long)(period_cycles + 2) * duty_ns;
|
|
do_div(c, period_ns);
|
|
duty_cycles = c;
|
|
|
|
--
|
|
1.5.4.4
|
|
|