max80_fw/rv32/i2c.h

#ifndef I2C_H
#define I2C_H

#include "common.h"
#include "atomic.h"
#include "io.h"

static inline uint32_t i2c_wait(void)
{
    waitfor(I2C_IRQ);
}

static inline void i2c_send_byte(uint8_t byte, uint8_t ctl)
{
    i2c_wait();
    I2C_WDATA = (byte << 8) | I2C_NAK | ctl;
}

static inline uint32_t i2c_data_status(void)
{
    i2c_wait();
    return I2C_RDATA;
}

static inline bool i2c_acked(void)
{
    return !(i2c_data_status() & I2C_NAK);
}

static inline uint8_t i2c_recv_byte(uint8_t ctl)
{
    uint32_t rdata;

    i2c_wait();
    I2C_WDATA = (~0xff) | ctl;

    return i2c_data_status() >> 8;
}

static inline void i2c_set_speed(unsigned int khz)
{
    I2C_DIVISOR = ((CPU_HZ/4000)-1)/khz;
}

extern volatile bool _i2c_locked;

static bool i2c_lock(void)
{
    return !atomic_xchg(_i2c_locked, true);
}
static void i2c_unlock(void)
{
    _i2c_locked = false;
}

#define I2C_ERR_BUSY		(-1)
#define I2C_ERR_CONFLICT	(-2)
#define I2C_ERR_NAK		(-3)
#define I2C_ERR_IO		(-4)
#define I2C_ERR_STUCK		(-5)
#define I2C_ERR_NODEV		(-6)

extern int i2c_send(uint8_t addr, const void *data, size_t len);
extern int i2c_recv(uint8_t addr, void *data, size_t len);
extern int i2c_send_recv(uint8_t addr, const void *odata, size_t olen,
			 void *idata, size_t ilen);

#endif /* I2C_H */