1 files changed, 176 insertions, 0 deletions

diff --git a/platforms/avr/drivers/ws2812.c b/platforms/avr/drivers/ws2812.c
new file mode 100644
index 000000000..77c492cd4
--- /dev/null
+++ b/platforms/avr/drivers/ws2812.c
@@ -0,0 +1,176 @@
+/*
+ * light weight WS2812 lib V2.0b
+ *
+ * Controls WS2811/WS2812/WS2812B RGB-LEDs
+ * Author: Tim (cpldcpu@gmail.com)
+ *
+ * Jan 18th, 2014  v2.0b Initial Version
+ * Nov 29th, 2015  v2.3  Added SK6812RGBW support
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "ws2812.h"
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+
+#define pinmask(pin) (_BV((pin)&0xF))
+
+/*
+ * Forward declare internal functions
+ *
+ * The functions take a byte-array and send to the data output as WS2812 bitstream.
+ * The length is the number of bytes to send - three per LED.
+ */
+
+static inline void ws2812_sendarray_mask(uint8_t *data, uint16_t datlen, uint8_t masklo, uint8_t maskhi);
+
+void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds) {
+    DDRx_ADDRESS(RGB_DI_PIN) |= pinmask(RGB_DI_PIN);
+
+    uint8_t masklo = ~(pinmask(RGB_DI_PIN)) & PORTx_ADDRESS(RGB_DI_PIN);
+    uint8_t maskhi = pinmask(RGB_DI_PIN) | PORTx_ADDRESS(RGB_DI_PIN);
+
+    ws2812_sendarray_mask((uint8_t *)ledarray, number_of_leds * sizeof(LED_TYPE), masklo, maskhi);
+
+    _delay_us(WS2812_TRST_US);
+}
+
+/*
+  This routine writes an array of bytes with RGB values to the Dataout pin
+  using the fast 800kHz clockless WS2811/2812 protocol.
+*/
+
+// Timing in ns
+#define w_zeropulse 350
+#define w_onepulse 900
+#define w_totalperiod 1250
+
+// Fixed cycles used by the inner loop
+#define w_fixedlow 2
+#define w_fixedhigh 4
+#define w_fixedtotal 8
+
+// Insert NOPs to match the timing, if possible
+#define w_zerocycles (((F_CPU / 1000) * w_zeropulse) / 1000000)
+#define w_onecycles (((F_CPU / 1000) * w_onepulse + 500000) / 1000000)
+#define w_totalcycles (((F_CPU / 1000) * w_totalperiod + 500000) / 1000000)
+
+// w1_nops - nops between rising edge and falling edge - low
+#if w_zerocycles >= w_fixedlow
+#    define w1_nops (w_zerocycles - w_fixedlow)
+#else
+#    define w1_nops 0
+#endif
+
+// w2_nops - nops between fe low and fe high
+#if w_onecycles >= (w_fixedhigh + w1_nops)
+#    define w2_nops (w_onecycles - w_fixedhigh - w1_nops)
+#else
+#    define w2_nops 0
+#endif
+
+// w3_nops - nops to complete loop
+#if w_totalcycles >= (w_fixedtotal + w1_nops + w2_nops)
+#    define w3_nops (w_totalcycles - w_fixedtotal - w1_nops - w2_nops)
+#else
+#    define w3_nops 0
+#endif
+
+// The only critical timing parameter is the minimum pulse length of the "0"
+// Warn or throw error if this timing can not be met with current F_CPU settings.
+#define w_lowtime ((w1_nops + w_fixedlow) * 1000000) / (F_CPU / 1000)
+#if w_lowtime > 550
+#    error "Light_ws2812: Sorry, the clock speed is too low. Did you set F_CPU correctly?"
+#elif w_lowtime > 450
+#    warning "Light_ws2812: The timing is critical and may only work on WS2812B, not on WS2812(S)."
+#    warning "Please consider a higher clockspeed, if possible"
+#endif
+
+#define w_nop1 "nop      \n\t"
+#define w_nop2 "rjmp .+0 \n\t"
+#define w_nop4 w_nop2 w_nop2
+#define w_nop8 w_nop4 w_nop4
+#define w_nop16 w_nop8 w_nop8
+
+static inline void ws2812_sendarray_mask(uint8_t *data, uint16_t datlen, uint8_t masklo, uint8_t maskhi) {
+    uint8_t curbyte, ctr, sreg_prev;
+
+    sreg_prev = SREG;
+    cli();
+
+    while (datlen--) {
+        curbyte = (*data++);
+
+        asm volatile("       ldi   %0,8  \n\t"
+                     "loop%=:            \n\t"
+                     "       out   %2,%3 \n\t"  //  '1' [01] '0' [01] - re
+#if (w1_nops & 1)
+                     w_nop1
+#endif
+#if (w1_nops & 2)
+                         w_nop2
+#endif
+#if (w1_nops & 4)
+                             w_nop4
+#endif
+#if (w1_nops & 8)
+                                 w_nop8
+#endif
+#if (w1_nops & 16)
+                                     w_nop16
+#endif
+                     "       sbrs  %1,7  \n\t"  //  '1' [03] '0' [02]
+                     "       out   %2,%4 \n\t"  //  '1' [--] '0' [03] - fe-low
+                     "       lsl   %1    \n\t"  //  '1' [04] '0' [04]
+#if (w2_nops & 1)
+                     w_nop1
+#endif
+#if (w2_nops & 2)
+                         w_nop2
+#endif
+#if (w2_nops & 4)
+                             w_nop4
+#endif
+#if (w2_nops & 8)
+                                 w_nop8
+#endif
+#if (w2_nops & 16)
+                                     w_nop16
+#endif
+                     "       out   %2,%4 \n\t"  //  '1' [+1] '0' [+1] - fe-high
+#if (w3_nops & 1)
+                     w_nop1
+#endif
+#if (w3_nops & 2)
+                         w_nop2
+#endif
+#if (w3_nops & 4)
+                             w_nop4
+#endif
+#if (w3_nops & 8)
+                                 w_nop8
+#endif
+#if (w3_nops & 16)
+                                     w_nop16
+#endif
+
+                     "       dec   %0    \n\t"  //  '1' [+2] '0' [+2]
+                     "       brne  loop%=\n\t"  //  '1' [+3] '0' [+4]
+                     : "=&d"(ctr)
+                     : "r"(curbyte), "I"(_SFR_IO_ADDR(PORTx_ADDRESS(RGB_DI_PIN))), "r"(maskhi), "r"(masklo));
+    }
+
+    SREG = sreg_prev;
+}