ats20/radio.c

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <util/delay.h>

#include <tool.h>
#include <i2c.h>
#include <radio.h>

void udelay(void) {
    #define _DELAY 100
    for (int i = 0; i < (_DELAY); i++) {
        __asm("nop");
    }
}


typedef struct {
    uint8_t status;
} radio_t;

radio_t radio;

uint8_t radio_get_status(void) {
    return radio.status;
}

#define RX_I2CADDR   0xC6
#define I2CADDR_WRITE_BIT  0

#define CMD_POWER_UP    0x01
#define CMD_GET_REV     0x10
#define CMD_POWER_DOWN  0x11
#define CMD_SET_PROP    0x12
#define CMD_GET_PROP    0x13
#define CMD_GET_INTSTAT 0x14

#define CMD_AM_TUNE_FREQ 0x40
#define CMD_FM_TUNE_FREQ 0x20

#define POWERUP_CTSIEN_BIT  7
#define POWERUP_GPO2OEN_BIT 6
#define POWERUP_PATCH_BIT   5
#define POWERUP_XOSCEN_BIT  4

#define POWERUP_FMRDS       0x00
#define POWERUP_AMSWLW      0x01
#define POWERUP_ANALOG      0x05

#define INT_CTS_BIT    7
#define INT_ERR_BIT    6
#define INT_RDSINT_BIT 2
#define INT_ASQINT_BIT 1
#define INT_STCIN_BIT  0

#define STATUS_CTS_BIT    7
#define STATUS_ERR_BIT    6
#define STATUS_RSQINT_BIT 3
#define STATUS_RDSINT_BIT 2
#define STATUS_STCINT_BIT 0

#define PROP_RX_VOLUME    0x4000
#define PROP_RX_HARD_MUTE 0x4001
#define PROP_HMUTE_L_BIT   1
#define PROP_HMUTE_R_BIT   0

#define HI_BYTE(word)    (((word) >> 8) & 0xFF)
#define LO_BYTE(word)    (((word) >> 0) & 0xFF)

#define RST_PIN PB4


uint8_t radio_read_cts(void) {
    uint8_t cts = 0;
    uint8_t rcount = 20;
    i2c_start();
    i2c_write(RX_I2CADDR);
    i2c_write(CMD_GET_INTSTAT);
    i2c_restart();
    i2c_write(RX_I2CADDR | BIT(I2CADDR_WRITE_BIT));
    for (uint8_t i = 0; i < rcount; i++) {
        cts = i2c_read_ack();
        if ((cts &= BIT(STATUS_CTS_BIT)) != 0) {
            break;
        }
    }
    i2c_read_nack();
    i2c_stop();
    return cts;
}


void radio_wait_cts(void) {
    uint8_t cts = 0;
    while ((cts &= BIT(STATUS_CTS_BIT)) == 0) {
        cts = radio_read_cts();
    }
}

void radio_powerup_fmrds(void) {
    i2c_start();
    i2c_write(RX_I2CADDR);
    i2c_write(CMD_POWER_UP);
    i2c_write(POWERUP_FMRDS | BIT(POWERUP_XOSCEN_BIT) | BIT(POWERUP_CTSIEN_BIT));
    i2c_write(POWERUP_ANALOG);
    i2c_stop();
    _delay_ms(300);
}

void radio_set_fm_freq(uint16_t freq) {

    i2c_start();
    i2c_write(RX_I2CADDR);
    i2c_write(CMD_FM_TUNE_FREQ);
    i2c_write(0x01);
    i2c_write(HI_BYTE(freq));
    i2c_write(LO_BYTE(freq));
    i2c_write(0);

#if 0
    uint8_t cts = 0x00;

    i2c_restart();
    i2c_write(RX_I2CADDR | BIT(I2CADDR_WRITE_BIT));

    while (cts == 0) {
        cts = i2c_read_ack();
        cts &= BIT(STATUS_CTS_BIT);
    }
    i2c_read_nack();
#endif
    i2c_stop();
}

void radio_set_rx_volume(uint8_t volume) {
    i2c_start();
    i2c_write(RX_I2CADDR);
    i2c_write(CMD_SET_PROP);
    i2c_write(0x00);
    i2c_write(HI_BYTE(PROP_RX_VOLUME));
    i2c_write(LO_BYTE(PROP_RX_VOLUME));
    i2c_write(0x00);
    i2c_write(volume);
    i2c_stop();
}

void radio_set_rx_mute(void) {
    i2c_start();
    i2c_write(RX_I2CADDR);
    i2c_write(CMD_SET_PROP);
    i2c_write(0x00);
    i2c_write(HI_BYTE(PROP_RX_HARD_MUTE));
    i2c_write(LO_BYTE(PROP_RX_HARD_MUTE));
    i2c_write(0x00);
    i2c_write(BIT(PROP_HMUTE_L_BIT));
    i2c_stop();
}

uint16_t radio_get_rev(void) {
    uint16_t rev = 0x0000;
    //i2c_write(CMD_GET_REV);
    //i2c_restart();
    //i2c_write(RX_I2CADDR | 0x01);
    //radio.status = i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_ack();
    //i2c_read_nack();
    //i2c_stop();
    return rev;
}

void radio_hw_reset(void) {
    REG_SETUP_BIT(DDRB, RST_PIN);
    REG_SETDOWN_BIT(PORTB, RST_PIN);
    _delay_ms(10);
    REG_SETUP_BIT(PORTB, RST_PIN);
    _delay_ms(10);
}

void radio_init(void) {
    radio.status = 0;

    radio_hw_reset();

    radio_powerup_fmrds();
    radio_wait_cts();

    uint16_t freq = 10010;
    radio_set_fm_freq(freq);
    radio_wait_cts();

    radio_set_rx_mute();
    radio_wait_cts();

    uint8_t volume = 38;
    radio_set_rx_volume(volume);
    radio_wait_cts();

    return;
}