eeprom_i2c.c

[詳解]

/** @file
    @brief       EEPROMドライバ(I2C接続)

    @date       2015.09.27
    @author     Takashi SHUDO

    @info

    24C1024等
    AKI-H8/3069用
*/

#include "device/i2c_ioctl.h"
#include "device.h"
#include "tkprintf.h"
#include "str.h"

#define USEBLOCKWRITE
#define DEV_ADDR0       0x50
#define DEV_ADDR1       0x51

#define EEPROMSIZE      ((long)1024*1024/8)     // 24C1024(1Mbits = 128KBytes)
#define ONEDEVSIZE      (64*1024)       // 1デバイスのバイト数
#define BLOCKSIZE       256     // 24C1024

static struct st_device *i2c_dev;
static char i2c_devname[MAX_DEVNAMELRN];
static unsigned long eeprom_addr;

static int eeprom_register(struct st_device *dev, char *param)
{
        eeprom_addr = 0;

        if(param == 0) {
                SYSERR_PRINT("No I2C device name\n");
                return -1;
        } else {
                strncopy((uchar *)i2c_devname, (uchar *)param, MAX_DEVNAMELRN);
        }

        return 0;
}

static int eeprom_unregister(struct st_device *dev)
{
        return 0;
}

static int eeprom_open(struct st_device *dev)
{
        return 0;
}

static int eeprom_close(struct st_device *dev)
{
        return 0;
}

static int eeprom_read(struct st_device *dev, void *data, unsigned int size)
{
        int rtn = 0;
        unsigned char dev_addr;

        i2c_dev = open_device(i2c_devname);

        if(i2c_dev == 0) {
                SYSERR_PRINT("Cannot open device %s.\n", i2c_devname);
                return -1;
        }

        if(eeprom_addr < ONEDEVSIZE) {
                dev_addr = DEV_ADDR0;
        } else {
                dev_addr = DEV_ADDR1;
        }
        // !!! デバイスをまたいだアクセスは出来ない
        lock_device(i2c_dev, 0);
        ioctl_device(i2c_dev, IOCMD_I2C_SLAVE_ADDR7, dev_addr, 0);
        ioctl_device(i2c_dev, IOCMD_I2C_MEMADDRSIZE, I2C_MEM_ADDR_SIZE_16BIT, 0);
        rtn = read_device(i2c_dev, data, size);
        unlock_device(i2c_dev);

        close_device(i2c_dev);

        eeprom_addr += rtn;
        // サイズオーバーは無視

        return rtn;
}

static int eeprom_write(struct st_device *dev, const void *data, unsigned int size)
{
        int rtn = 0;
        unsigned char dev_addr;

        i2c_dev = open_device(i2c_devname);

        if(i2c_dev == 0) {
                SYSERR_PRINT("Cannot open device %s.\n", i2c_devname);
                return -1;
        }

        if(eeprom_addr < ONEDEVSIZE) {
                dev_addr = DEV_ADDR0;
        } else {
                dev_addr = DEV_ADDR1;
        }
        // !!! デバイスをまたいだアクセスは出来ない
        lock_device(i2c_dev, 0);
        ioctl_device(i2c_dev, IOCMD_I2C_SLAVE_ADDR7, dev_addr, 0);
        ioctl_device(i2c_dev, IOCMD_I2C_MEMADDRSIZE, I2C_MEM_ADDR_SIZE_16BIT, 0);
        rtn = write_device(i2c_dev, data, size);
        unlock_device(i2c_dev);

        close_device(i2c_dev);

        eeprom_addr += rtn;
        // サイズオーバーは無視

        return rtn;
}

static int eeprom_seek(struct st_device *dev, int offset, int whence)
{
        switch(whence) {
        case SEEK_SET:
                eeprom_addr = offset;
                break;
                
        case SEEK_CUR:
                eeprom_addr += offset;
                break;

        case SEEK_END:
                eeprom_addr = EEPROMSIZE - offset;
                break;
                
        default:
                return -1;
        }
        
        return eeprom_addr;
}

const struct st_device eeprom_device = {
        .name           = DEF_DEV_NAME_EEPRMOM,
        .explan         = "EEPROM(24C1024)",
        .register_dev   = eeprom_register,
        .unregister_dev = eeprom_unregister,
        .open           = eeprom_open,
        .close          = eeprom_close,
        .read           = eeprom_read,
        .write          = eeprom_write,
        .seek           = eeprom_seek
};