/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * * Copyright (C) 2008 by Jens Arnold * * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "config.h" #define RS_MASK 0x00010000 #define CLOCK_MASK 0x10000000 #define GPIO_OUT_ADDR 0x80000004 #define CS_MASK 0x00000004 /* used in moveq.l */ #define DATA_MASK 0x00040000 #define GPIO1_OUT_ADDR 0x800000b4 #define CS_TIMEOUT 10 /* HZ/10 */ .extern cpu_frequency /* Global variable from system.c */ .extern remote_byte_delay /* Global variable from lcd-remote-iriver.c */ .extern remote_cs_countdown /* Global variable from lcd-remote-iriver.c */ .section .icode,"ax",@progbits /* Output 8 bits to the LCD. Instruction order is devised to maximize the * delay between changing the data line and the CLK L->H transition, which * makes the LCD controller sample DATA. * Requires CLK = 0 on entry. * * Custom calling convention: * %a0 - GPIO_OUT_ADDR * %a1 - GPIO1_OUT_ADDR * %d4 - data byte * %d6 - DATA_MASK * Clobbers: * %d0..%d4 */ #ifdef HAVE_REMOTE_LCD_TICKING .write_byte_delayed: move.l remote_byte_delay, %d0 1: subq.l #1, %d0 bne.s 1b #endif .write_byte: move.w %sr, %d3 /* Get current interrupt level */ move.w #0x2700, %sr /* Disable interrupts */ move.l (%a1), %d0 /* Get current state of data port */ move.l %d0, %d1 and.l %d6, %d1 /* Check current state of data line */ beq.s 1f /* and set it as previous-state bit */ bset #8, %d4 1: move.l %d4, %d1 /* Compute the 'bit derivative', i.e. a value */ lsr.l #1, %d1 /* with 1's where the data changes from the */ eor.l %d1, %d4 /* previous state, and 0's where it doesn't */ swap %d4 /* Shift data to upper byte */ lsl.l #8, %d4 move.l (%a0),%d1 /* Get current state of clock port */ move.l %d1, %d2 /* Precalculate opposite state of clock line */ eor.l #CLOCK_MASK, %d2 lsl.l #1, %d4 /* Invert data line for bit7 ? */ bcc.s 1f /* no: skip */ eor.l %d6, %d0 /* invert data bit */ move.l %d0, (%a1) /* output data bit7 */ nop nop 1: .macro bit_out move.l %d2, (%a0) /* Bit7: set CLK = 1 */ nop lsl.l #1, %d4 /* Invert data line for bit6 ? */ bcc.s 1f /* no: skip */ eor.l %d6, %d0 /* Invert data bit */ move.l %d1, (%a0) /* set CLK = 0 */ move.l %d0, (%a1) /* Output data bit6 */ .word 0x51fa /* trapf.w - shadow next insn */ 1: move.l %d1, (%a0) /* set CLK = 0 */ .endm bit_out nop nop bit_out nop nop bit_out nop nop bit_out nop nop bit_out nop nop bit_out nop nop bit_out nop nop move.l %d2, (%a0) /* Bit0: Set CLK = 1 */ nop nop move.l %d1, (%a0) /* Set CLK = 0 */ move.w %d3, %sr /* Restore interrupt level */ rts /* Output 8 bits to the LCD as fast as possible. Use only at < 60MHz. * * Custom calling convention: * %a0 - GPIO_OUT_ADDR * %a1 - GPIO1_OUT_ADDR * %d4 - data word * %d6 - DATA_MASK * Clobbers: * %d0..%d4 */ #ifdef HAVE_REMOTE_LCD_TICKING .write_byte_fast_delayed: move.l remote_byte_delay, %d0 1: subq.l #1, %d0 bne.s 1b #endif .write_byte_fast: move.w %sr, %d3 /* Get current interrupt level */ move.w #0x2700,%sr /* Disable interrupts */ move.l (%a1), %d0 /* Get current state of data port */ move.l %d0, %d1 and.l %d6, %d1 /* Check current state of data line */ beq.s 1f /* and set it as previous-state bit */ bset #8, %d4 1: move.l %d4, %d1 /* Compute the 'bit derivative', i.e. a value */ lsr.l #1, %d1 /* with 1's where the data changes from the */ eor.l %d1, %d4 /* previous state, and 0's where it doesn't */ swap %d4 /* Shift data to upper byte */ lsl.l #8, %d4 move.l (%a0), %d1 /* Get current state of clock port */ move.l %d1, %d2 /* Precalculate opposite state of clock line */ eor.l #CLOCK_MASK, %d2 .macro bit_out_fast lsl.l #1,%d4 /* Shift out MSB */ bcc.s 1f eor.l %d6, %d0 /* 1: flip data bit */ move.l %d0, (%a1) /* and output new DATA state */ 1: move.l %d2, (%a0) /* Set CLK */ move.l %d1, (%a0) /* Reset CLK */ .endm bit_out_fast bit_out_fast bit_out_fast bit_out_fast bit_out_fast bit_out_fast bit_out_fast bit_out_fast move.w %d3, %sr /* Restore interrupt level */ rts .global lcd_remote_write_command .type lcd_remote_write_command, @function lcd_remote_write_command: lea.l (-4*4, %sp), %sp movem.l %d2-%d4/%d6, (%sp) move.l (4*4+4, %sp), %d4 /* cmd */ lea.l GPIO_OUT_ADDR, %a0 lea.l GPIO1_OUT_ADDR, %a1 move.l #DATA_MASK, %d6 clr.l remote_cs_countdown move.l #~RS_MASK, %d0 and.l %d0, (%a0) moveq.l #~CS_MASK, %d0 and.l %d0, (%a1) #ifdef HAVE_REMOTE_LCD_TICKING tst.l remote_byte_delay ble.s 1f bsr.w .write_byte_delayed bra.s 2f 1: #endif bsr.w .write_byte 2: moveq.l #CS_TIMEOUT, %d0 move.l %d0, remote_cs_countdown movem.l (%sp), %d2-%d4/%d6 lea.l (4*4, %sp), %sp rts .global lcd_remote_write_command_ex .type lcd_remote_write_command_ex, @function lcd_remote_write_command_ex: lea.l (-4*4, %sp), %sp movem.l %d2-%d4/%d6, (%sp) lea.l GPIO_OUT_ADDR, %a0 lea.l GPIO1_OUT_ADDR, %a1 move.l #DATA_MASK, %d6 clr.l remote_cs_countdown move.l #~RS_MASK, %d0 and.l %d0, (%a0) moveq.l #~CS_MASK, %d0 and.l %d0, (%a1) move.l (4*4+4, %sp), %d4 #ifdef HAVE_REMOTE_LCD_TICKING tst.l remote_byte_delay ble.s 1f bsr.w .write_byte_delayed move.l (4*4+8, %sp), %d4 bsr.w .write_byte_delayed bra.s 2f 1: #endif bsr.w .write_byte move.l (4*4+8, %sp), %d4 bsr.w .write_byte 2: moveq.l #CS_TIMEOUT, %d0 move.l %d0, remote_cs_countdown movem.l (%sp), %d2-%d4/%d6 lea.l (4*4, %sp), %sp rts .global lcd_remote_write_data .type lcd_remote_write_data, @function lcd_remote_write_data: lea.l (-7*4, %sp), %sp movem.l %d2-%d6/%a2-%a3, (%sp) move.l (7*4+4, %sp), %a2 /* p_bytes */ move.l (7*4+8, %sp), %d5 /* count */ lea.l GPIO_OUT_ADDR, %a0 lea.l GPIO1_OUT_ADDR, %a1 move.l #DATA_MASK, %d6 lea.l .write_byte, %a3 move.l cpu_frequency, %d0 cmp.l #60000000, %d0 bhi.b 1f lea.l .write_byte_fast, %a3 1: #ifdef HAVE_REMOTE_LCD_TICKING tst.l remote_byte_delay ble.s 1f moveq.l #(.write_byte_delayed - .write_byte), %d0 add.l %d0, %a3 1: #endif clr.l remote_cs_countdown move.l #RS_MASK, %d0 or.l %d0, (%a0) moveq.l #~CS_MASK, %d0 and.l %d0, (%a1) .wd_loop: clr.l %d4 move.b (%a2)+, %d4 jsr (%a3) subq.l #1, %d5 bne.s .wd_loop moveq.l #CS_TIMEOUT, %d0 move.l %d0, remote_cs_countdown movem.l (%sp), %d2-%d6/%a2-%a3 lea.l (7*4, %sp), %sp rts