| 1 |
15 |
dgisselq |
////////////////////////////////////////////////////////////////////////////////
|
| 2 |
|
|
//
|
| 3 |
|
|
// Filename: display.c
|
| 4 |
|
|
//
|
| 5 |
|
|
// Project: CMod S6 System on a Chip, ZipCPU demonstration project
|
| 6 |
|
|
//
|
| 7 |
|
|
// Purpose: A device driver for the SPI controlled display. The primary
|
| 8 |
|
|
// purpose of this "device" is to output SPI instructions, though,
|
| 9 |
|
|
// not to handle screen position or to optimize data set to the display.
|
| 10 |
|
|
//
|
| 11 |
|
|
// Creator: Dan Gisselquist, Ph.D.
|
| 12 |
|
|
// Gisselquist Technology, LLC
|
| 13 |
|
|
//
|
| 14 |
|
|
////////////////////////////////////////////////////////////////////////////////
|
| 15 |
|
|
//
|
| 16 |
|
|
// Copyright (C) 2015-2016, Gisselquist Technology, LLC
|
| 17 |
|
|
//
|
| 18 |
|
|
// This program is free software (firmware): you can redistribute it and/or
|
| 19 |
|
|
// modify it under the terms of the GNU General Public License as published
|
| 20 |
|
|
// by the Free Software Foundation, either version 3 of the License, or (at
|
| 21 |
|
|
// your option) any later version.
|
| 22 |
|
|
//
|
| 23 |
|
|
// This program is distributed in the hope that it will be useful, but WITHOUT
|
| 24 |
|
|
// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
|
| 25 |
|
|
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
| 26 |
|
|
// for more details.
|
| 27 |
|
|
//
|
| 28 |
|
|
// You should have received a copy of the GNU General Public License along
|
| 29 |
|
|
// with this program. (It's in the $(ROOT)/doc directory, run make with no
|
| 30 |
|
|
// target there if the PDF file isn't present.) If not, see
|
| 31 |
|
|
// <http://www.gnu.org/licenses/> for a copy.
|
| 32 |
|
|
//
|
| 33 |
|
|
// License: GPL, v3, as defined and found on www.gnu.org,
|
| 34 |
|
|
// http://www.gnu.org/licenses/gpl.html
|
| 35 |
|
|
//
|
| 36 |
|
|
//
|
| 37 |
|
|
////////////////////////////////////////////////////////////////////////////////
|
| 38 |
|
|
//
|
| 39 |
|
|
//
|
| 40 |
|
|
#include "board.h"
|
| 41 |
|
|
|
| 42 |
|
|
static void dispwait(void) {
|
| 43 |
|
|
// Slow us down to the speed the display can handle
|
| 44 |
|
|
// We want to delay about 0x800 clocks.
|
| 45 |
|
|
// Three instructions per loop,
|
| 46 |
|
|
// LBL:
|
| 47 |
|
|
// NOOP
|
| 48 |
|
|
// ADD -1,CTR
|
| 49 |
|
|
// BNZ LBL
|
| 50 |
|
|
// 40 clocks per instruction, as required by the SPI flash memory
|
| 51 |
|
|
int i = 18;
|
| 52 |
|
|
do {
|
| 53 |
|
|
asm("noop");
|
| 54 |
|
|
} while(i-->0);
|
| 55 |
|
|
}
|
| 56 |
|
|
|
| 57 |
|
|
void dispchar(int ch) {
|
| 58 |
|
|
if (!ch) // Don't display null characters
|
| 59 |
|
|
return;
|
| 60 |
|
|
if (ch&(~0x0ff)) { // Multiple characters to display
|
| 61 |
|
|
int v = (ch>>24)&0x0ff;
|
| 62 |
|
|
if (v) {
|
| 63 |
|
|
dispchar(v);
|
| 64 |
|
|
v = (ch>>16)&0x0ff;
|
| 65 |
|
|
if (v) {
|
| 66 |
|
|
dispchar(v);
|
| 67 |
|
|
v = (ch>> 8)&0x0ff;
|
| 68 |
|
|
if (v) {
|
| 69 |
|
|
dispchar(v);
|
| 70 |
|
|
dispchar(ch&0x0ff);
|
| 71 |
|
|
}
|
| 72 |
|
|
}
|
| 73 |
|
|
}
|
| 74 |
|
|
} else {
|
| 75 |
|
|
IOSPACE *sys = (IOSPACE *)IOADDR;
|
| 76 |
|
|
// Send the character
|
| 77 |
|
|
for(int i=0; i<8; i++) {
|
| 78 |
|
|
int gpiov = GPOCLRV(GPO_MOSI|GPO_SCK|GPO_SS);
|
| 79 |
|
|
if (ch&0x80)
|
| 80 |
|
|
gpiov |= GPOSETV(GPO_MOSI);
|
| 81 |
|
|
sys->io_gpio = gpiov;
|
| 82 |
|
|
dispwait();
|
| 83 |
|
|
sys->io_gpio = GPOSETV(GPO_SCK);
|
| 84 |
|
|
dispwait();
|
| 85 |
|
|
ch<<=1;
|
| 86 |
|
|
}
|
| 87 |
|
|
// Turn off the clock
|
| 88 |
|
|
sys->io_gpio = GPOCLRV(GPO_SCK);
|
| 89 |
|
|
dispwait();
|
| 90 |
|
|
// Then the port
|
| 91 |
|
|
sys->io_gpio = GPOSETV(GPO_SS);
|
| 92 |
|
|
dispwait();
|
| 93 |
|
|
}
|
| 94 |
|
|
}
|
| 95 |
|
|
|
| 96 |
|
|
#ifdef ZIPOS
|
| 97 |
|
|
void displaytask(void) {
|
| 98 |
|
|
while(1) {
|
| 99 |
|
|
int ch;
|
| 100 |
|
|
read(FILENO_STDIN, &ch, 1);
|
| 101 |
|
|
dispchar(ch);
|
| 102 |
|
|
}
|
| 103 |
|
|
}
|
| 104 |
|
|
#endif
|
