samd21: Get beep code working

Only supports TCC currently.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/samd21/ao_beep_samd21.c b/src/samd21/ao_beep_samd21.c
index eabe8a1605795def863dad75e06414ae8fe8dc7e..7fbbcba19828887668ed3b37a4617039e916f629 100644 (file)
--- a/src/samd21/ao_beep_samd21.c
+++ b/src/samd21/ao_beep_samd21.c
@@ -19,10 +19,18 @@
 #include "ao.h"
 #include "ao_beep.h"
 
+#define BEEP_SCALE     (AO_SYSCLK / 750000)
+
 void
 ao_beep(uint8_t beep)
 {
-       (void) beep;
+       struct samd21_tcc *tcc = AO_BEEP_TCC;
+       if (beep) {
+               tcc->per = (beep * BEEP_SCALE);
+               tcc->ctrla = (1 << SAMD21_TCC_CTRLA_ENABLE);
+       } else {
+               tcc->ctrla = (0 << SAMD21_TCC_CTRLA_ENABLE);
+       }
 }
 
 void
@@ -33,7 +41,56 @@ ao_beep_for(uint8_t beep, AO_TICK_TYPE ticks)
        ao_beep(0);
 }
 
+static void
+ao_tcc_init(struct samd21_tcc *tcc, uint32_t apbcmask)
+{
+       samd21_pm.apbcmask |= apbcmask;
+
+       /* Reset the device */
+       tcc->ctrla = (1 << SAMD21_TCC_CTRLA_SWRST);
+
+       while ((tcc->ctrla & (1 << SAMD21_TCC_CTRLA_SWRST)) != 0 ||
+              (tcc->syncbusy & (1 << SAMD21_TCC_SYNCBUSY_SWRST)) != 0)
+               ;
+
+       tcc->per = 94 * BEEP_SCALE;
+
+       tcc->wave = ((SAMD21_TCC_WAVE_WAVEGEN_NFRQ << SAMD21_TCC_WAVE_WAVEGEN) |
+                    (0 << SAMD21_TCC_WAVE_RAMP) |
+                    (0 << SAMD21_TCC_WAVE_CIPEREN) |
+                    (0 << SAMD21_TCC_WAVE_CCCEN(0)) |
+                    (0 << SAMD21_TCC_WAVE_CCCEN(1)) |
+                    (0 << SAMD21_TCC_WAVE_CCCEN(2)) |
+                    (0 << SAMD21_TCC_WAVE_CCCEN(3)) |
+                    (0 << SAMD21_TCC_WAVE_POL(0)) |
+                    (0 << SAMD21_TCC_WAVE_POL(1)) |
+                    (0 << SAMD21_TCC_WAVE_POL(1)) |
+                    (0 << SAMD21_TCC_WAVE_POL(3)) |
+                    (0 << SAMD21_TCC_WAVE_SWAP(0)) |
+                    (0 << SAMD21_TCC_WAVE_SWAP(1)) |
+                    (0 << SAMD21_TCC_WAVE_SWAP(1)) |
+                    (0 << SAMD21_TCC_WAVE_SWAP(3)));
+
+       tcc->dbgctrl = (1 << SAMD21_TCC_DBGCTRL_DBGRUN);
+}
+
 void
 ao_beep_init(void)
 {
+       struct samd21_port      *port = AO_BEEP_PORT;
+       uint8_t                 pin = AO_BEEP_PIN;
+       struct samd21_tcc       *tcc = AO_BEEP_TCC;
+       uint32_t                apbc_mask = 1UL << AO_BEEP_TCC_APBC_MASK;
+
+       if (tcc == &samd21_tcc0 || tcc == &samd21_tcc1) {
+               samd21_gclk_clkctrl(0, SAMD21_GCLK_CLKCTRL_ID_TCC0_TCC1);
+       } else {
+               samd21_gclk_clkctrl(0, SAMD21_GCLK_CLKCTRL_ID_TCC2_TC3);
+       }
+
+       ao_tcc_init(tcc, apbc_mask);
+
+       ao_enable_output(port, pin, 0);
+
+       samd21_port_pmux_set(port, pin, AO_BEEP_FUNC);
 }