mirror of
git://projects.qi-hardware.com/ben-blinkenlights.git
synced 2024-11-16 17:22:29 +02:00
130 lines
2.8 KiB
C
130 lines
2.8 KiB
C
/*
|
|
* bbl.c - Produce a "Knight Rider" effect on the LED board
|
|
*
|
|
* Written 2010-2011 by Werner Almesberger <werner@openmoko.org>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
|
|
#include <unistd.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <signal.h>
|
|
#include <fcntl.h>
|
|
#include <sys/mman.h>
|
|
|
|
|
|
#define GPIO_BASE 0x10010000
|
|
|
|
#define REG(n) (*(volatile uint32_t *) (mem+(n)-GPIO_BASE))
|
|
|
|
/*
|
|
* The XBurst CPUs use an interesting concept for setting GPIOs: instead of
|
|
* writing the value of a pin (0 or 1) directly to an output latch, the latch
|
|
* is set by writing a 1 to a "set" register and cleared by writing a 1 to a
|
|
* "clear" register. This way, only an atomic store but no atomic
|
|
* read-modify-write operations are necessary for changing only part of the
|
|
* bits on a port.
|
|
*
|
|
* The same set/clear mechanism is also used for the other writable registers
|
|
* affecting GPIOs, e.g., the direction (input/output) and function (GPIO or
|
|
* MMC) registers.
|
|
*/
|
|
|
|
#define PDDATS REG(0x10010314) /* port D data set */
|
|
#define PDDATC REG(0x10010318) /* port D data clear */
|
|
#define PDFUNC REG(0x10010348) /* port D function clear */
|
|
#define PDDIRS REG(0x10010364) /* port D direction set */
|
|
#define PDDIRC REG(0x10010368) /* port D direction clear */
|
|
|
|
#define LEDS 10 /* number of LEDs */
|
|
|
|
#define GROUP_SEL 11 /* PD11, DAT1 - LED group selection */
|
|
|
|
#define LED_MASK 0x3f00 /* all the LED groups and GROUP_SEL */
|
|
|
|
#define DELAY_US 50000
|
|
|
|
#define PAGE_SIZE 4096
|
|
|
|
static volatile void *mem;
|
|
|
|
|
|
static int map(int group)
|
|
{
|
|
switch (group) {
|
|
case 0:
|
|
return 12; /* PD12, DAT2 */
|
|
case 1:
|
|
return 13; /* PD13, DAT3/CD */
|
|
case 2:
|
|
return 8; /* PD08, CMD */
|
|
case 3:
|
|
return 9; /* PD09, CLK */
|
|
case 4:
|
|
return 10; /* PD10, DAT0 */
|
|
default:
|
|
abort();
|
|
}
|
|
}
|
|
|
|
|
|
static void set(int n)
|
|
{
|
|
|
|
if (n & 1) {
|
|
PDDATC = LED_MASK;
|
|
PDDATS = 1 << map(n >> 1);
|
|
} else {
|
|
PDDATS = LED_MASK;
|
|
PDDATC = 1 << map(n >> 1);
|
|
}
|
|
}
|
|
|
|
|
|
static void die(int sig)
|
|
{
|
|
PDDIRC = LED_MASK; /* make all MMC pins inputs again */
|
|
_exit(0);
|
|
}
|
|
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int fd, i;
|
|
|
|
fd = open("/dev/mem", O_RDWR | O_SYNC);
|
|
if (fd < 0) {
|
|
perror("/dev/mem");
|
|
exit(1);
|
|
}
|
|
mem = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
|
|
GPIO_BASE);
|
|
if (mem == MAP_FAILED) {
|
|
perror("mmap");
|
|
exit(1);
|
|
}
|
|
|
|
signal(SIGINT, die);
|
|
|
|
PDFUNC = LED_MASK; /* make all MMC pins GPIOs */
|
|
PDDIRS = LED_MASK; /* make all MMC pins outputs */
|
|
|
|
while (1) {
|
|
for (i = 0; i != LEDS-1; i++) {
|
|
set(i);
|
|
usleep(DELAY_US);
|
|
}
|
|
for (i = LEDS-1; i != 0; i--) {
|
|
set(i);
|
|
usleep(DELAY_US);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|