From cf7299c09e7663eb9b3a6bf78c7aa421a2c24c22 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Wed, 21 Oct 2015 12:42:52 +0200
Subject: [PATCH] cpu/stm32f3: adapted to PWM interface changes

---
 cpu/stm32f3/periph/pwm.c | 58 +++++++++++++++++++++++-----------------
 1 file changed, 34 insertions(+), 24 deletions(-)

diff --git a/cpu/stm32f3/periph/pwm.c b/cpu/stm32f3/periph/pwm.c
index 2b4a165c08..21d727bba3 100644
--- a/cpu/stm32f3/periph/pwm.c
+++ b/cpu/stm32f3/periph/pwm.c
@@ -22,13 +22,16 @@
 #include <string.h>
 
 #include "cpu.h"
-#include "periph/pwm.h"
 #include "periph_conf.h"
 
-/* ignore file in case no PWM devices are defined */
-#if PWM_0_EN || PWM_1_EN
+/* guard file in case no PWM device is defined */
+#if (PWM_0_EN || PWM_1_EN)
 
-int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int resolution)
+/* pull the PWM header inside the guards for now. Guards will be removed on
+ * adapting this driver implementation... */
+#include "periph/pwm.h"
+
+uint32_t pwm_init(pwm_t dev, pwm_mode_t mode, uint32_t freq, uint16_t res)
 {
     TIM_TypeDef *tim = NULL;
     GPIO_TypeDef *port = NULL;
@@ -70,7 +73,7 @@ int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int re
 #endif
         default:
             pwm_poweroff(dev);
-            return -1;
+            return 0;
     }
 
     /* setup pins: alternate function */
@@ -94,12 +97,12 @@ int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int re
     tim->CCMR2 = 0;
 
     /* set prescale and auto-reload registers to matching values for resolution and frequency */
-    if ((resolution > 0xffff) || ((resolution * frequency) > pwm_clk)) {
-        return -2;
+    if ((res > 0xffff) || ((res * freq) > pwm_clk)) {
+        return 0;
     }
-    tim->PSC = (pwm_clk / (resolution * frequency)) - 1;
-    tim->ARR = resolution - 1;
-    frequency = (pwm_clk / (resolution * (tim->PSC + 1)));
+    tim->PSC = (pwm_clk / (res * freq)) - 1;
+    tim->ARR = res - 1;
+    freq = (pwm_clk / (res * (tim->PSC + 1)));
 
     /* set PWM mode */
     switch (mode) {
@@ -126,10 +129,26 @@ int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int re
     /* enable PWM generation */
     pwm_start(dev);
 
-    return frequency;
+    return freq;
 }
 
-int pwm_set(pwm_t dev, int channel, unsigned int value)
+uint8_t pwm_channels(pwm_t dev)
+{
+    switch (dev) {
+#if PWM_0_EN
+        case PWM_0:
+            return PWM_0_CHANNELS;
+#endif
+#if PWM_1_EN
+        case PWM_1:
+            return PWM_1_CHANNELS;
+#endif
+        default:
+            return 0;
+    }
+}
+
+void pwm_set(pwm_t dev, uint8_t channel, uint16_t value)
 {
     TIM_TypeDef *tim = NULL;
 
@@ -145,14 +164,7 @@ int pwm_set(pwm_t dev, int channel, unsigned int value)
             break;
 #endif
         default:
-            return -1;
-    }
-
-    /* norm value to maximum possible value
-     * Caution! A duty cycle exceeding the period length can lead to unexpected
-     * behaviour on other MCUs. */
-    if (value > 0xffff) {
-        value = 0xffff;
+            return;
     }
 
     switch (channel) {
@@ -169,10 +181,8 @@ int pwm_set(pwm_t dev, int channel, unsigned int value)
             tim->CCR4 = value;
             break;
         default:
-            return -2;
+            return;
     }
-
-    return 0;
 }
 
 void pwm_start(pwm_t dev)
@@ -239,4 +249,4 @@ void pwm_poweroff(pwm_t dev)
     }
 }
 
-#endif /* PWM_0_EN || PWM_1_EN */
+#endif /* (PWM_0_EN || PWM_1_EN) */