i2c.h

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#ifndef DRV_I2C_H
#define DRV_I2C_H

#include "cfg/cfg_i2c.h"

#include <cfg/compiler.h>
#include <cfg/macros.h>
#include <cfg/debug.h>

#include <cpu/attr.h>

#define I2C_READBIT BV(0)


/*
 * The following macros are needed to maintain compatibility with older i2c API.
 * They can be safely removed once the old API is removed.
 */

#if COMPILER_C99
    #define i2c_init(...)           PP_CAT(i2c_init ## _, COUNT_PARMS(__VA_ARGS__)) (__VA_ARGS__)
    #define i2c_start_w(...)        PP_CAT(i2c_start_w ## _, COUNT_PARMS(__VA_ARGS__)) (__VA_ARGS__)
    #define i2c_start_r(...)        PP_CAT(i2c_start_r ## _, COUNT_PARMS(__VA_ARGS__)) (__VA_ARGS__)
#else

    #define i2c_init(args...)       PP_CAT(i2c_init ## _, COUNT_PARMS(args)) (args)

    #define i2c_start_w(args...)    PP_CAT(i2c_start_w ## _, COUNT_PARMS(args)) (args)

    #define i2c_start_r(args...)    PP_CAT(i2c_start_r ## _, COUNT_PARMS(args)) (args)
#endif

enum
{
    I2C_BITBANG_OLD = -1,
    I2C_BITBANG0 = 1000, 
    I2C_BITBANG1,        
    I2C_BITBANG2,
    I2C_BITBANG3,
    I2C_BITBANG4,
    I2C_BITBANG5,
    I2C_BITBANG6,
    I2C_BITBANG7,
    I2C_BITBANG8,
    I2C_BITBANG9,

    I2C_BITBANG_CNT  
};

#define I2C_OK               0     ///< I2C no errors flag
#define I2C_DATA_NACK     BV(4)    ///< I2C generic error
#define I2C_ERR           BV(3)    ///< I2C generic error
#define I2C_ARB_LOST      BV(2)    ///< I2C arbitration lost error
#define I2C_START_TIMEOUT BV(0)    ///< I2C timeout error on start
#define I2C_NO_ACK        BV(1)    ///< I2C no ack for sla start

#define I2C_NOSTOP           0    ///< Do not program the stop for current transition
#define I2C_STOP          BV(0)   ///< Program the stop for current transition

#define I2C_START_R       BV(1)   // Start read command
#define I2C_START_W          0    // Start write command


#define I2C_TEST_START(flag)  ((flag) & I2C_START_R)
#define I2C_TEST_STOP(flag)   ((flag) & I2C_STOP)

struct I2cHardware;
struct I2c;

typedef void (*i2c_start_t)(struct I2c *i2c, uint16_t slave_addr);
typedef uint8_t (*i2c_getc_t)(struct I2c *i2c);
typedef void (*i2c_putc_t)(struct I2c *i2c, uint8_t data);
typedef void (*i2c_write_t)(struct I2c *i2c, const void *_buf, size_t count);
typedef void (*i2c_read_t)(struct I2c *i2c, void *_buf, size_t count);

typedef struct I2cVT
{
    i2c_start_t start;
    i2c_getc_t   getc;
    i2c_putc_t   putc;
    i2c_write_t  write;
    i2c_read_t   read;
} I2cVT;

typedef struct I2c
{
    int errors;
    int flags;
    size_t xfer_size;
    struct I2cHardware* hw;
    const struct I2cVT *vt;
} I2c;


#include CPU_HEADER(i2c)

/*
 * Low level i2c  init implementation prototype.
 */
void i2c_hw_init(I2c *i2c, int dev, uint32_t clock);
void i2c_hw_bitbangInit(I2c *i2c, int dev);

void i2c_genericWrite(I2c *i2c, const void *_buf, size_t count);
void i2c_genericRead(I2c *i2c, void *_buf, size_t count);

/*
 * Start a i2c transfer.
 *
 * \param i2c Context structure.
 * \param slave_addr Address of slave device
 * \param size Size of the transfer
 */
INLINE void i2c_start(I2c *i2c, uint16_t slave_addr, size_t size)
{
    ASSERT(i2c->vt);
    ASSERT(i2c->vt->start);

    if (!i2c->errors)
        ASSERT(i2c->xfer_size == 0);

    i2c->errors = 0;
    i2c->xfer_size = size;

    i2c->vt->start(i2c, slave_addr);
}

INLINE void i2c_start_r_4(I2c *i2c, uint16_t slave_addr, size_t size, int flags)
{
    ASSERT(i2c);
    i2c->flags = flags | I2C_START_R;
    i2c_start(i2c, slave_addr, size);
}

INLINE void i2c_start_w_4(I2c *i2c, uint16_t slave_addr, size_t size, int flags)
{
    ASSERT(i2c);
    i2c->flags = flags & ~I2C_START_R;
    i2c_start(i2c, slave_addr, size);
}

INLINE uint8_t i2c_getc(I2c *i2c)
{
    ASSERT(i2c);
    ASSERT(i2c->vt);
    ASSERT(i2c->vt->getc);

    ASSERT(i2c->xfer_size);

    ASSERT(I2C_TEST_START(i2c->flags) == I2C_START_R);

    if (!i2c->errors)
    {
        uint8_t data = i2c->vt->getc(i2c);
        i2c->xfer_size--;
        return data;
    }
    else
        return 0xFF;
}

INLINE void i2c_putc(I2c *i2c, uint8_t data)
{
    ASSERT(i2c);
    ASSERT(i2c->vt);
    ASSERT(i2c->vt->putc);

    ASSERT(i2c->xfer_size);

    ASSERT(I2C_TEST_START(i2c->flags) == I2C_START_W);

    if (!i2c->errors)
    {
        i2c->vt->putc(i2c, data);
        i2c->xfer_size--;
    }
}

INLINE void i2c_write(I2c *i2c, const void *_buf, size_t count)
{
    ASSERT(i2c);
    ASSERT(i2c->vt);
    ASSERT(i2c->vt->write);

    ASSERT(_buf);
    ASSERT(count);
    ASSERT(count <= i2c->xfer_size);

    ASSERT(I2C_TEST_START(i2c->flags) == I2C_START_W);

    if (!i2c->errors)
        i2c->vt->write(i2c, _buf, count);
}

INLINE void i2c_read(I2c *i2c, void *_buf, size_t count)
{
    ASSERT(i2c);
    ASSERT(i2c->vt);
    ASSERT(i2c->vt->read);

    ASSERT(_buf);
    ASSERT(count);
    ASSERT(count <= i2c->xfer_size);

    ASSERT(I2C_TEST_START(i2c->flags) == I2C_START_R);

    if (!i2c->errors)
        i2c->vt->read(i2c, _buf, count);
}

INLINE int i2c_error(I2c *i2c)
{
    ASSERT(i2c);
    int err = i2c->errors;
    i2c->errors = 0;

    return err;
}

#define i2c_init_3(i2c, dev, clock)   ((((dev) >= I2C_BITBANG0) | ((dev) == I2C_BITBANG_OLD)) ? \
                                        i2c_hw_bitbangInit((i2c), (dev)) : i2c_hw_init((i2c), (dev), (clock)))
 // i2c_api

#if !CONFIG_I2C_DISABLE_OLD_API

#define I2C_BACKEND_BUILTIN 0 ///< Uses cpu builtin i2c driver
#define I2C_BACKEND_BITBANG 1 ///< Uses emulated bitbang driver

bool i2c_builtin_start_w(uint8_t id);
bool i2c_builtin_start_r(uint8_t id);
void i2c_builtin_stop(void);
bool i2c_builtin_put(uint8_t _data);
int i2c_builtin_get(bool ack);
bool i2c_bitbang_start_w(uint8_t id);
bool i2c_bitbang_start_r(uint8_t id);
void i2c_bitbang_stop(void);
bool i2c_bitbang_put(uint8_t _data);
int i2c_bitbang_get(bool ack);
#ifndef CONFIG_I2C_BACKEND
#define  CONFIG_I2C_BACKEND  I2C_BACKEND_BUILTIN
#endif

#if CONFIG_I2C_BACKEND == I2C_BACKEND_BUILTIN
    #define i2c_start_w_1   i2c_builtin_start_w
    #define i2c_start_r_1   i2c_builtin_start_r
    #define i2c_stop        i2c_builtin_stop
    #define i2c_put         i2c_builtin_put
    #define i2c_get         i2c_builtin_get
#elif CONFIG_I2C_BACKEND == I2C_BACKEND_BITBANG
    #define i2c_start_w_1   i2c_bitbang_start_w
    #define i2c_start_r_1   i2c_bitbang_start_r
    #define i2c_stop        i2c_bitbang_stop
    #define i2c_put         i2c_bitbang_put
    #define i2c_get         i2c_bitbang_get
#else
    #error Unsupported i2c backend.
#endif


bool i2c_send(const void *_buf, size_t count);
bool i2c_recv(void *_buf, size_t count);

extern I2c local_i2c_old_api;

INLINE void i2c_init_0(void)
{
    #if CONFIG_I2C_BACKEND == I2C_BACKEND_BITBANG
        i2c_init_3(&local_i2c_old_api, I2C_BITBANG_OLD, CONFIG_I2C_FREQ);
    #else
        i2c_init_3(&local_i2c_old_api, 0, CONFIG_I2C_FREQ);
    #endif
}
#endif /* !CONFIG_I2C_DISABLE_OLD_API */
 //defgroup i2c_driver

#endif