[WIP] WS2812 driver

common.mk

@@ -5,6 +5,7 @@ $(TARGET)_INCLUDE += \
   -I$(CMSIS_PATH)/source \
   -I$(ATMEL_PATH)/include \
 
+
 $(TARGET)_SRC += \
   common/startup_samd21.c \
   common/clock.c \

firmware.mk

@@ -3,6 +3,10 @@ TARGET := firmware
 include common.mk
 include usb.mk
 
+$(TARGET)_INCLUDE += \
+  -I$(DRIVERS_PATH) \
+  -I$(DRIVERS_PATH)/system/interrupt/ \
+
 $(TARGET)_SRC += \
   firmware/main.c \
   firmware/usb.c \
@@ -11,6 +15,7 @@ $(TARGET)_SRC += \
   firmware/port.c \
   firmware/usbpipe.c \
   firmware/usbserial.c \
+  firmware/ws2812.c \
 
 $(TARGET)_LDSCRIPT = common/samd21g15a_firmware_partition.ld
 $(TARGET)_DEFINE += -D __SAMD21G15A__

firmware/firmware.h

@@ -162,3 +162,8 @@ void usbserial_in_completion();
 void usbserial_dma_rx_completion();
 void usbserial_dma_tx_completion();
 void usbserial_handle_tc();
+
+// ws2812.c
+void ws2812_init(Pin p);
+void ws2812_set_dma_addr(Pin p, void *addr);
+void ws2812_begin_animation(Pin p);

firmware/main.c

@@ -104,6 +104,9 @@ int main(void) {
     port_init(&port_b, 2, &PORT_B, GCLK_PORT_B,
         TCC_PORT_B, DMA_PORT_B_TX, DMA_PORT_B_RX);
 
+    // TEMPORARY
+    ws2812_init(PORT_B.power);
+
     __enable_irq();
     SCB->SCR |= SCB_SCR_SLEEPONEXIT_Msk;
     while (1) { __WFI(); }

firmware/ws2812.c

@@ -0,0 +1,69 @@
+#include "firmware.h"
+#include "tcc/tcc.h"
+
+void _ws2812_set_pin_mux(Pin p);
+void _ws2812_enable_clock();
+void _ws2812_enable_tcc();
+
+/*
+Initializes the Counter Control of a specific pin
+so that it's ready to output a waveform compatible
+with the ws2812 protocol
+*/
+void ws2812_init(Pin p) {
+
+  _ws2812_set_pin_mux(p);
+
+  _ws2812_enable_clock();
+
+  _ws2812_enable_tcc();
+}
+
+/*
+Sets the pin function to use the CCT
+Section 30.5.1
+*/
+void _ws2812_set_pin_mux(Pin p) {
+  int8_t tcc_func = 0x05;
+
+  if (p.pin & 1) {
+    PORT->Group[p.group].PMUX[p.pin/2].bit.PMUXO = tcc_func;
+  } else {
+    PORT->Group[p.group].PMUX[p.pin/2].bit.PMUXE = tcc_func;
+  }
+
+  PORT->Group[p.group].PINCFG[p.pin].bit.PMUXEN = 1;
+
+}
+
+/*
+Starts up the peripheral clock for the specific TCC used by the pin
+Section 30.5.3
+*/
+void _ws2812_enable_clock() {
+  // system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, TCC0_GCLK_ID)
+  // TODO enable appropriate clock based on pin
+  // (GCLK_TCC0 vs GCLK_TCC1, etc.)
+  PM->APBCMASK.reg |= PM_APBCMASK_TCC0;
+    // GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN |
+    //     GCLK_CLKCTRL_GEN(GCLK_SYSTEM) |
+    //     GCLK_CLKCTRL_ID(TCC0_GCLK_ID);
+}
+
+void _ws2812_enable_tcc() {
+
+}
+
+/*
+Sets the DMA address the pin should read from
+*/
+void ws2812_set_dma_addr(Pin p, void *addr) {
+
+}
+
+/* 
+Begins an animation on a particular pin
+*/
+void ws2812_begin_animation(Pin p) {
+
+}