From 4d90a9c6b5f3293d6d3bb488f99aa44a476d80d6 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benpicco@beuth-hochschule.de>
Date: Fri, 3 Apr 2020 00:46:46 +0200
Subject: [PATCH] cpu/samd21: pwm: fix GCLK_ID & APBCMASK calculation

GCLK_ID and APBCMASK entries are not always uniform.
The previous hack would already break for TCC3.

Just explosively write down the cases, there are only 5 at most.
---
 cpu/samd21/periph/pwm.c | 55 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 46 insertions(+), 9 deletions(-)

diff --git a/cpu/samd21/periph/pwm.c b/cpu/samd21/periph/pwm.c
index 8cf442eb78..d6389c5821 100644
--- a/cpu/samd21/periph/pwm.c
+++ b/cpu/samd21/periph/pwm.c
@@ -30,11 +30,6 @@
 #include "periph/gpio.h"
 #include "periph/pwm.h"
 
-static inline int _num(pwm_t dev)
-{
-    return ((int)(pwm_config[dev].dev) & 0xc00) >> 10;
-}
-
 static inline Tcc *_tcc(pwm_t dev)
 {
     return pwm_config[dev].dev;
@@ -47,10 +42,52 @@ static inline uint8_t _chan(pwm_t dev, int chan)
 
 static int _clk_id(pwm_t dev)
 {
-    if (_num(dev) == 2) {
+    Tcc *tcc = _tcc(dev);
+
+    if (tcc == TCC0) {
+        return TCC0_GCLK_ID;
+    }
+
+    if (tcc == TCC1) {
+        return TCC1_GCLK_ID;
+    }
+
+    if (tcc == TCC2) {
         return TCC2_GCLK_ID;
     }
-    return TCC0_GCLK_ID;
+#ifdef TCC3
+    if (tcc == TCC3) {
+        return TCC3_GCLK_ID;
+    }
+#endif
+
+    assert(0);
+    return 0;
+}
+
+static uint32_t _apbcmask_tcc(pwm_t dev)
+{
+    Tcc *tcc = _tcc(dev);
+
+    if (tcc == TCC0) {
+        return PM_APBCMASK_TCC0;
+    }
+
+    if (tcc == TCC1) {
+        return PM_APBCMASK_TCC1;
+    }
+
+    if (tcc == TCC2) {
+        return PM_APBCMASK_TCC2;
+    }
+#ifdef TCC3
+    if (tcc == TCC3) {
+        return PM_APBCMASK_TCC3;
+    }
+#endif
+
+    assert(0);
+    return 0;
 }
 
 static uint8_t get_prescaler(unsigned int target, int *scale)
@@ -89,7 +126,7 @@ static uint8_t get_prescaler(unsigned int target, int *scale)
 
 static void poweron(pwm_t dev)
 {
-    PM->APBCMASK.reg |= (PM_APBCMASK_TCC0 << _num(dev));
+    PM->APBCMASK.reg |= _apbcmask_tcc(dev);
     GCLK->CLKCTRL.reg = (GCLK_CLKCTRL_CLKEN |
                          GCLK_CLKCTRL_GEN_GCLK0 |
                          GCLK_CLKCTRL_ID(_clk_id(dev)));
@@ -189,7 +226,7 @@ void pwm_poweroff(pwm_t dev)
 {
     _tcc(dev)->CTRLA.reg &= ~(TCC_CTRLA_ENABLE);
 
-    PM->APBCMASK.reg &= ~(PM_APBCMASK_TCC0 << _num(dev));
+    PM->APBCMASK.reg &= ~_apbcmask_tcc(dev);
     GCLK->CLKCTRL.reg = (GCLK_CLKCTRL_GEN_GCLK7 |
                          GCLK_CLKCTRL_ID(_clk_id(dev)));
     while (GCLK->STATUS.bit.SYNCBUSY) {}