Exynos: Tidy up the pwm_config function in the exynos pwm driver

[platform/kernel/u-boot.git] / arch / arm / cpu / armv7 / s5p-common / pwm.c

diff --git a/arch/arm/cpu/armv7/s5p-common/pwm.c b/arch/arm/cpu/armv7/s5p-common/pwm.c
index 02156d1..6f401b8 100644 (file)
--- a/arch/arm/cpu/armv7/s5p-common/pwm.c
+++ b/arch/arm/cpu/armv7/s5p-common/pwm.c
@@ -70,7 +70,7 @@ static unsigned long pwm_calc_tin(int pwm_id, unsigned long freq)
        return tin_parent_rate / 16;
 }
 
-#define NS_IN_HZ (1000000000UL)
+#define NS_IN_SEC 1000000000UL
 
 int pwm_config(int pwm_id, int duty_ns, int period_ns)
 {
@@ -79,7 +79,7 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
        unsigned int offset;
        unsigned long tin_rate;
        unsigned long tin_ns;
-       unsigned long period;
+       unsigned long frequency;
        unsigned long tcon;
        unsigned long tcnt;
        unsigned long tcmp;
@@ -89,34 +89,24 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
         * fact that anything faster than 1GHz is easily representable
         * by 32bits.
         */
-       if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
+       if (period_ns > NS_IN_SEC || duty_ns > NS_IN_SEC || period_ns == 0)
                return -ERANGE;
 
        if (duty_ns > period_ns)
                return -EINVAL;
 
-       period = NS_IN_HZ / period_ns;
+       frequency = NS_IN_SEC / period_ns;
 
        /* Check to see if we are changing the clock rate of the PWM */
-       tin_rate = pwm_calc_tin(pwm_id, period);
+       tin_rate = pwm_calc_tin(pwm_id, frequency);
 
-       tin_ns = NS_IN_HZ / tin_rate;
+       tin_ns = NS_IN_SEC / tin_rate;
        tcnt = period_ns / tin_ns;
 
        /* Note, counters count down */
        tcmp = duty_ns / tin_ns;
        tcmp = tcnt - tcmp;
 
-       /*
-        * the pwm hw only checks the compare register after a decrement,
-        * so the pin never toggles if tcmp = tcnt
-        */
-       if (tcmp == tcnt)
-               tcmp--;
-
-       if (tcmp < 0)
-               tcmp = 0;
-
        /* Update the PWM register block. */
        offset = pwm_id * 3;
        if (pwm_id < 4) {