From 5ca1fd4275021590b4293c74c415b0780d004716 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Wed, 18 Sep 2024 20:21:55 +0200
Subject: [PATCH] avr: added module for sk6812 LED controllers.

---
 avr/modules/0BUILD          |   1 +
 avr/modules/sk6812/0BUILD   |  11 +++
 avr/modules/sk6812/main.asm | 178 ++++++++++++++++++++++++++++++++++++
 3 files changed, 190 insertions(+)
 create mode 100644 avr/modules/sk6812/0BUILD
 create mode 100644 avr/modules/sk6812/main.asm

diff --git a/avr/modules/0BUILD b/avr/modules/0BUILD
index 4ee28d5..caebd42 100644
--- a/avr/modules/0BUILD
+++ b/avr/modules/0BUILD
@@ -19,6 +19,7 @@
     twimaster
     owimaster
     ds18b20
+    sk6812
   </subdirs>
 
 </gwbuild>
diff --git a/avr/modules/sk6812/0BUILD b/avr/modules/sk6812/0BUILD
new file mode 100644
index 0000000..febd367
--- /dev/null
+++ b/avr/modules/sk6812/0BUILD
@@ -0,0 +1,11 @@
+<?xml?>
+
+<gwbuild>
+
+  <extradist>
+    main.asm
+  </extradist>
+
+</gwbuild>
+
+
diff --git a/avr/modules/sk6812/main.asm b/avr/modules/sk6812/main.asm
new file mode 100644
index 0000000..219b05b
--- /dev/null
+++ b/avr/modules/sk6812/main.asm
@@ -0,0 +1,178 @@
+; ***************************************************************************
+; copyright   : (C) 2024 by Martin Preuss
+; email       : martin@libchipcard.de
+;
+; ***************************************************************************
+; * This file is part of the project "AqHome".                              *
+; * Please see toplevel file COPYING of that project for license details.   *
+; ***************************************************************************
+
+
+
+; ***************************************************************************
+; defines
+
+
+
+; ***************************************************************************
+; data
+
+.dseg
+
+sk6812DataBegin:
+  sk6812NumLeds: .byte 1
+sk6812DataEnd:
+
+
+
+; ***************************************************************************
+; code
+
+.cseg
+
+
+SK6812_BEGIN:
+
+
+
+; ---------------------------------------------------------------------------
+; SK6812_Init
+;
+; IN:
+; - nothing
+; OUT:
+; - CFLAG: set if okay, clear on error
+; USED:
+
+SK6812_Init:
+;  ldi xh, HIGH(sk6812DataBegin)
+;  ldi xl, LOW(sk6812DataBegin)
+;  clr r16
+;  ldi r17, (sk6812DataEnd-sk6812DataBegin)
+;  rcall Utils_FillSram
+  sbi SK6812_DDR, SK6812_PINNUM    ; set to output
+  cbi SK6812_PORT, SK6812_PINNUM   ; set LOW
+  ldi r16, 150
+  sts sk6812NumLeds, r16
+
+  ldi r18, 255            ; R
+  ldi r19, 69             ; G
+  ldi r20, 0              ; B
+  ldi r21, 0              ; W
+  rcall SK6812_SetAllColor ; r23 (r16, r17)
+
+  sec
+  ret
+SK6812_Init_error:
+  clc
+  ret
+
+
+; ---------------------------------------------------------------------------
+; SK6812_Fini
+;
+; IN:
+; - nothing
+; OUT:
+; - CFLAG: set if okay, clear on error
+; USED:
+
+SK6812_Fini:
+  sec
+  ret
+
+
+
+; ---------------------------------------------------------------------------
+; @routine SK6812_SetAllColor @global
+;
+; Set all LEDs to same colour.
+;
+; @param r18 red value
+; @param r19 green value
+; @param r20 blue value
+; @param r21 white value
+; @clobbers r23 (r16, r17)
+
+SK6812_SetAllColor:
+  push r15
+    in r15, SREG
+    cli
+    lds r23, sk6812NumLeds
+SK6812_SetAllColor_loop:
+      rcall sk6812SendQuadruple ; (r16, r17)
+      dec r23
+    brne SK6812_SetAllColor_loop
+    out SREG, r15
+  pop r15
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine sk6812SendQuadruple
+;
+; Sends GRBW
+; @param r18 red value
+; @param r19 green value
+; @param r20 blue value
+; @param r21 white value
+; @clobbers r16 (r17)
+
+sk6812SendQuadruple:
+  mov r16, r19     ; G
+  rcall sk6812SendByte
+  mov r16, r18     ; R
+  rcall sk6812SendByte
+  mov r16, r20     ; B
+  rcall sk6812SendByte
+  mov r16, r21     ; W
+  rcall sk6812SendByte
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine sk6812SendByte
+;
+; @param r16 value
+; @clobbers r16, r17, r24, r25
+
+
+
+sk6812SendByte:
+  ldi r17, 8                         ; +1
+  ldi r24, (1<<SK6812_PINNUM)
+  clr r25
+sk6812SendByte_loop:
+    lsl r16                          ; +1
+    brcs sk6812SendByte_sendOne      ; +1 if false, +2 if branch taken
+    nop                              ; +1
+    ; send ZERO
+    out SK6812_PORT, r24             ; +1 set HIGH
+    nop                              ; +1
+    out SK6812_PORT, r25             ; +1 set LOW
+    dec r17                          ; +1
+  brne sk6812SendByte_loop           ; +1 if false, +2 if branch taken
+  ret                                ; 4
+  
+sk6812SendByte_sendOne:
+    out SK6812_PORT, r24             ; +1 set HIGH
+    nop                              ; +1
+    nop                              ; +1
+    nop                              ; +1
+    nop                              ; +1
+    out SK6812_PORT, r25             ; +1 set LOW
+    dec r17                          ; +1
+  brne sk6812SendByte_loop           ; +2
+  ret
+; @end
+
+
+
+SK6812_END:
+.equ MODULE_SIZE_SK6812 = SK6812_END-SK6812_BEGIN
+
+