SPI
How to use SPI
root@odroid:~# lsmod Module Size Used by uinput 6669 1 ir_lirc_codec 4243 3 lirc_dev 10110 1 ir_lirc_codec ir_mce_kbd_decoder 3092 0 ir_sanyo_decoder 1638 0 ir_sony_decoder 1667 0 ir_jvc_decoder 1664 0 ir_rc6_decoder 2024 0 ir_rc5_decoder 1552 0 ir_nec_decoder 1776 0 meson_ir 2902 0 joydev 8607 0 hid_logitech_dj 11642 0 fuse 70879 2 nls_cp437 5125 1
root@odroid:~# modprobe spicc
root@odroid:~# lsmod Module Size Used by ads7846 13766 0 spidev 5465 0 spicc 7846 0 uinput 6669 1 ir_lirc_codec 4243 3 lirc_dev 10110 1 ir_lirc_codec ir_mce_kbd_decoder 3092 0 ir_sanyo_decoder 1638 0 ir_sony_decoder 1667 0 ir_jvc_decoder 1664 0 ir_rc6_decoder 2024 0 ir_rc5_decoder 1552 0 ir_nec_decoder 1776 0 meson_ir 2902 0 joydev 8607 0 hid_logitech_dj 11642 0 fuse 70879 2 nls_cp437 5125 1
root@odroid:~# ls /dev/spidev0.0 /dev/spidev0.0 root@odroid:~#
Compile & run SPI test example source code
gcc -o spidev_test spidev_test.c
odroid@odroid:~$ ./spidev_test spi mode: 0 bits per word: 8 max speed: 500000 Hz (500 KHz)
- spidev_test.c
/* * SPI testing utility (using spidev driver) * * Copyright (c) 2007 MontaVista Software, Inc. * Copyright (c) 2007 Anton Vorontsov <avorontsov@ru.mvista.com> * * 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. * * Cross-compile with cross-gcc -I/path/to/cross-kernel/include */ #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/spi/spidev.h> #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) #define uchar unsigned char #define MAX_RAW 36 #define MAX_COLUMN 8 uchar disp1[MAX_RAW][MAX_COLUMN] = { {0x3C,0x42,0x42,0x42,0x42,0x42,0x42,0x3C},//0 {0x10,0x30,0x50,0x10,0x10,0x10,0x10,0x7C},//1 {0x3E,0x02,0x02,0x3E,0x20,0x20,0x3E,0x00},//2 {0x00,0x7C,0x04,0x04,0x7C,0x04,0x04,0x7C},//3 {0x08,0x18,0x28,0x48,0xFE,0x08,0x08,0x08},//4 {0x3C,0x20,0x20,0x3C,0x04,0x04,0x3C,0x00},//5 {0x3C,0x20,0x20,0x3C,0x24,0x24,0x3C,0x00},//6 {0x3E,0x22,0x04,0x08,0x08,0x08,0x08,0x08},//7 {0x00,0x3E,0x22,0x22,0x3E,0x22,0x22,0x3E},//8 {0x3E,0x22,0x22,0x3E,0x02,0x02,0x02,0x3E},//9 {0x08,0x14,0x22,0x3E,0x22,0x22,0x22,0x22},//A {0x3C,0x22,0x22,0x3E,0x22,0x22,0x3C,0x00},//B {0x3C,0x40,0x40,0x40,0x40,0x40,0x3C,0x00},//C {0x7C,0x42,0x42,0x42,0x42,0x42,0x7C,0x00},//D {0x7C,0x40,0x40,0x7C,0x40,0x40,0x40,0x7C},//E {0x7C,0x40,0x40,0x7C,0x40,0x40,0x40,0x40},//F {0x3C,0x40,0x40,0x40,0x40,0x44,0x44,0x3C},//G {0x44,0x44,0x44,0x7C,0x44,0x44,0x44,0x44},//H {0x7C,0x10,0x10,0x10,0x10,0x10,0x10,0x7C},//I {0x3C,0x08,0x08,0x08,0x08,0x08,0x48,0x30},//J {0x00,0x24,0x28,0x30,0x20,0x30,0x28,0x24},//K {0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x7C},//L {0x81,0xC3,0xA5,0x99,0x81,0x81,0x81,0x81},//M {0x00,0x42,0x62,0x52,0x4A,0x46,0x42,0x00},//N {0x3C,0x42,0x42,0x42,0x42,0x42,0x42,0x3C},//O {0x3C,0x22,0x22,0x22,0x3C,0x20,0x20,0x20},//P {0x1C,0x22,0x22,0x22,0x22,0x26,0x22,0x1D},//Q {0x3C,0x22,0x22,0x22,0x3C,0x24,0x22,0x21},//R {0x00,0x1E,0x20,0x20,0x3E,0x02,0x02,0x3C},//S {0x00,0x3E,0x08,0x08,0x08,0x08,0x08,0x08},//T {0x42,0x42,0x42,0x42,0x42,0x42,0x22,0x1C},//U {0x42,0x42,0x42,0x42,0x42,0x42,0x24,0x18},//V {0x00,0x49,0x49,0x49,0x49,0x2A,0x1C,0x00},//W {0x00,0x41,0x22,0x14,0x08,0x14,0x22,0x41},//X {0x41,0x22,0x14,0x08,0x08,0x08,0x08,0x08},//Y {0x00,0x7F,0x02,0x04,0x08,0x10,0x20,0x7F},//Z }; static void pabort(const char *s) { perror(s); abort(); } static const char *device_spidev0_0 = "/dev/spidev0.0"; static const char *device_spidev1_0 = "/dev/spidev1.0"; static uint8_t mode; static uint8_t bits = 8; static uint32_t speed = 500000; static void transfer(int fd, uchar address1, uchar dat1, uchar address2, uchar dat2) { int ret; uint8_t tx[] = { address1, dat1, address2, dat2 }; uint8_t rx[ARRAY_SIZE(tx)] = {0, }; struct spi_ioc_transfer tr; tr.tx_buf = (unsigned long)tx; tr.rx_buf = (unsigned long)rx; tr.len = ARRAY_SIZE(tx); tr.speed_hz = speed; tr.bits_per_word = bits; tr.delay_usecs = 0; tr.cs_change = 0; ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send SPI message"); } int main() { uchar i , j; int ret = 0; int fd; fd = open(device_spidev0_0, O_RDWR); if (fd < 0) { printf("can't open /dev/spidev0.0\nTry /dev/spidev1.0\n"); fd = open(device_spidev1_0, O_RDWR); if (fd < 0) pabort("can't open /dev/spidev1.0"); } /* SPI mode */ ret = ioctl(fd, SPI_IOC_WR_MODE, &mode); if (ret == -1) pabort("can't set SPI mode"); ret = ioctl(fd, SPI_IOC_RD_MODE, &mode); if (ret == -1) pabort("can't get SPI mode"); /* bits per word */ ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits); if (ret == -1) pabort("can't set bits per word"); ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits); if (ret == -1) pabort("can't get bits per word"); /* max speed hz */ ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed); if (ret == -1) pabort("can't set max speed Hz"); ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed); if (ret == -1) pabort("can't get max speed Hz"); printf("SPI mode: %d\n", mode); printf("bits per word: %d\n", bits); printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000); transfer(fd, 0x09,0x00,0x09,0x00); transfer(fd, 0x0a,0x03,0x0a,0x03); transfer(fd, 0x0b,0x07,0x0b,0x07); transfer(fd, 0x0c,0x01,0x0c,0x01); transfer(fd, 0x0f,0x00,0x0f,0x00); while (1) { for(j = 0; j < MAX_RAW - 1; j++) { for(i = 1; i < MAX_COLUMN + 1; i++) transfer(fd, i, disp1[j + 1][i - 1], i, disp1[j][i - 1]); usleep(1000000); } } close(fd); return ret; }
