/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Alan Korr * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include #include "system.h" #define LCDR (PBDR_ADDR+1) #ifdef HAVE_LCD_CHARCELLS #define LCD_DS 1 /* PB0 = 1 --- 0001 --- LCD-DS */ #define LCD_CS 2 /* PB1 = 1 --- 0010 --- /LCD-CS */ #define LCD_SD 4 /* PB2 = 1 --- 0100 --- LCD-SD */ #define LCD_SC 8 /* PB3 = 1 --- 1000 --- LCD-SC */ #else #define LCD_SD 1 /* PB0 = 1 --- 0001 */ #define LCD_SC 2 /* PB1 = 1 --- 0010 */ #define LCD_RS 4 /* PB2 = 1 --- 0100 */ #define LCD_CS 8 /* PB3 = 1 --- 1000 */ #define LCD_DS LCD_RS #endif /* * About /CS,DS,SC,SD * ------------------ * * LCD on JBP and JBR uses a SPI protocol to receive orders (SDA and SCK lines) * * - /CS -> Chip Selection line : * 0 : LCD chipset is activated. * - DS -> Data Selection line, latched at the rising edge * of the 8th serial clock (*) : * 0 : instruction register, * 1 : data register; * - SC -> Serial Clock line (SDA). * - SD -> Serial Data line (SCK), latched at the rising edge * of each serial clock (*). * * _ _ * /CS \ / * \______________________________________________________/ * _____ ____ ____ ____ ____ ____ ____ ____ ____ _____ * SD \/ D7 \/ D6 \/ D5 \/ D4 \/ D3 \/ D2 \/ D1 \/ D0 \/ * _____/\____/\____/\____/\____/\____/\____/\____/\____/\_____ * * _____ _ _ _ _ _ _ _ ________ * SC \ * \ * \ * \ * \ * \ * \ * \ * * \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ * _ _________________________________________________________ * DS \/ * _/\_________________________________________________________ * */ /* * The only way to do logical operations in an atomic way * on SH1 is using : * * or.b/and.b/tst.b/xor.b #imm,@(r0,gbr) * * but GCC doesn't generate them at all so some assembly * codes are needed here. * * The Global Base Register gbr is expected to be zero * and r0 is the address of one register in the on-chip * peripheral module. * */ void lcd_write(bool command, int byte) __attribute__ ((section (".icode"))); void lcd_write(bool command, int byte) { asm("and.b %0, @(r0,gbr)" : : /* %0 */ "I"(~(LCD_CS|LCD_DS|LCD_SD|LCD_SC)), /* %1 */ "z"(LCDR)); if (command) asm ("shll8 %0\n" "0: \n\t" "and.b %2,@(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3,@(r0,gbr)\n" "1: \n\t" "or.b %4,@(r0,gbr)\n" "add #-1,%1\n\t" "cmp/pl %1\n\t" "bt 0b" : : /* %0 */ "r"(((unsigned)byte)<<16), /* %1 */ "r"(8), /* %2 */ "I"(~(LCD_SC|LCD_SD|LCD_DS)), /* %3 */ "I"(LCD_SD), /* %4 */ "I"(LCD_SC), /* %5 */ "z"(LCDR)); else asm ("shll8 %0\n" "0: \n\t" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" "and.b %2, @(r0,gbr)\n\t" "shll %0\n\t" "bf 1f\n\t" "or.b %3, @(r0,gbr)\n" "1: \n\t" "or.b %4, @(r0,gbr)\n" : : /* %0 */ "r"(((unsigned)byte)<<16), /* %1 */ "r"(8), /* %2 */ "I"(~(LCD_SC|LCD_SD)), /* %3 */ "I"(LCD_SD|LCD_DS), /* %4 */ "I"(LCD_SC|LCD_DS), /* %5 */ "z"(LCDR)); asm("or.b %0, @(r0,gbr)" : : /* %0 */ "I"(LCD_CS|LCD_DS|LCD_SD|LCD_SC), /* %1 */ "z"(LCDR)); } /* A high performance function to write data to the display, one or multiple bytes. Ultimately, all calls to lcd_write(false, xxx) should be substituted by this, it will be most efficient if the LCD buffer is tilted to have the X row as consecutive bytes, so we can write a whole row */ /* FixMe: somehow the red LED is affected by this, although I don't touch any other bit. Therefore not used yet, except for lcd_blit() */ void lcd_write_data(unsigned char* p_bytes, int count) __attribute__ ((section (".icode"))); void lcd_write_data(unsigned char* p_bytes, int count) { do { unsigned byte; unsigned sda1; /* precalculated SC=low,SD=1 */ unsigned clk0sda0; /* precalculated SC and SD low */ byte = *p_bytes++ << 24; /* fetch to MSB position */ cli(); /* make port modifications atomic */ /* precalculate the values for later bit toggling, init data write */ asm ( "mov.b @%2,%0\n" /* sda1 = PBDRL */ "or %4,%0\n" /* sda1 |= LCD_DS | LCD_SD DS and SD high, */ "and %3,%0\n" /* sda1 &= ~(LCD_CS | LCD_SC) CS and SC low */ "mov %0,%1\n" /* sda1 -> clk0sda0 */ "and %5,%1\n" /* clk0sda0 &= ~LCD_SD both low */ "mov.b %1,@%2\n" /* PBDRL = clk0sda0 */ : // outputs /* %0 */ "=r"(sda1), /* %1 */ "=r"(clk0sda0) : // inputs /* %2 */ "r"(LCDR), /* %3 */ "r"(~(LCD_CS | LCD_SC)), /* %4 */ "r"(LCD_DS | LCD_SD), /* %5 */ "r"(~LCD_SD) ); /* unrolled loop to serialize the byte */ asm ( "mov %4,r0\n" /* we need &PBDRL in r0 for "or.b x,@(r0,gbr)" */ "shll %0\n" /* shift the MSB into carry */ "bf 1f\n" "mov.b %1,@%4\n" /* if it was a "1": set SD high, SC low still */ "1: \n" "or.b %2, @(r0,gbr)\n" /* rise SC (independent of SD level) */ "shll %0\n" /* shift for next round, now for longer hold time */ "mov.b %3,@%4\n" /* SC and SD low again */ "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "shll %0\n" "mov.b %3,@%4\n" "bf 1f\n" "mov.b %1,@%4\n" "1: \n" "or.b %2, @(r0,gbr)\n" "or.b %5, @(r0,gbr)\n" /* restore port */ : : /* %0 */ "r"(byte), /* %1 */ "r"(sda1), /* %2 */ "I"(LCD_SC), /* %3 */ "r"(clk0sda0), /* %4 */ "r"(LCDR), /* %5 */ "I"(LCD_CS|LCD_DS|LCD_SD|LCD_SC) : "r0" ); sti(); } while (--count); /* tail loop is faster */ }