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Subject[41/75] ARM:imx:fix pwm period value
3.1-stable review patch.  If anyone has any objections, please let me know.

------------------
From: Jason Chen <jason.chen@linaro.org>

commit 5776ac2eb33164c77cdb4d2b48feee15616eaba3 upstream.

According to imx pwm RM, the real period value should be
PERIOD value in PWMPR plus 2.

PWMO (Hz) = PCLK(Hz) / (period +2)

Signed-off-by: Jason Chen <jason.chen@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/arm/plat-mxc/pwm.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/arch/arm/plat-mxc/pwm.c
+++ b/arch/arm/plat-mxc/pwm.c
@@ -77,6 +77,15 @@ int pwm_config(struct pwm_device *pwm, i
do_div(c, period_ns);
duty_cycles = c;

+ /*
+ * according to imx pwm RM, the real period value should be
+ * PERIOD value in PWMPR plus 2.
+ */
+ if (period_cycles > 2)
+ period_cycles -= 2;
+ else
+ period_cycles = 0;
+
writel(duty_cycles, pwm->mmio_base + MX3_PWMSAR);
writel(period_cycles, pwm->mmio_base + MX3_PWMPR);




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