56 lines
1014 B
C
56 lines
1014 B
C
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#include <stdio.h>
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#include <fcntl.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include <stdint.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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#include <stdlib.h>
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int i2c_init(const char *dev, uint8_t addr) {
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int fd = -1;
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fd = open(dev, O_RDWR);
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if (fd < 0) {
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fprintf(stderr, "could not open device: %s\n", dev);
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return -1;
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}
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if (ioctl(fd, I2C_SLAVE, addr) < 0) {
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fprintf(stderr, "failed to acquire bus/talk to slave\n");
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close(fd);
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return -1;
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}
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return fd;
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}
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int i2c_read_reg(int fd, uint8_t reg, uint8_t length, uint8_t *buf) {
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uint8_t cmd[2] = {reg, 0x00};
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write(fd, cmd, 2);
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if (read(fd, buf, length) != length) {
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fprintf(stderr, "error read()\n");
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return 1;
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}
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return 0;
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}
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uint8_t i2c_read_reg2(int fd, uint8_t reg) {
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uint8_t buf;
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i2c_read_reg(fd, reg, 1, &buf);
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return buf;
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}
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int i2c_write_reg(int fd, uint8_t reg, uint8_t value) {
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uint8_t cmd[2] = {reg, value};
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if (write(fd, cmd, 2) != 2) {
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fprintf(stderr, "error write()\n");
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return 1;
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}
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return 0;
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}
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