/*
 * File      : ls1c_i2c.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2017-09-06     ÇÚΪ±¾       first version
 */

// ·â×°Ó²¼þi2c½Ó¿Ú


#include "ls1c_public.h"
#include "ls1c_regs.h"
#include "ls1c_clock.h"
#include "ls1c_i2c.h"
#include "ls1c_delay.h"



/*
 * I2C¸÷¸ö¼Ä´æÆ÷Ïà¶Ô»ùµØÖ·µÄÆ«ÒÆ
 * ·¢ËÍÊý¾Ý¼Ä´æÆ÷ºÍ½ÓÊÕÊý¾Ý¼Ä´æÆ÷µÄÆ«ÒÆÊÇÏàͬµÄ
 * ÃüÁî¼Ä´æÆ÷ºÍ״̬¼Ä´æÆ÷µÄÆ«ÒÆÊÇÏàͬµÄ£¬²»Í¬µÄÊÇÃüÁî¼Ä´æÆ÷ֻд£¬×´Ì¬¼Ä´æÆ÷Ö»¶Á
 */
#define LS1C_I2C_PRER_LOW_OFFSET            (0)     // ·ÖÆµËø´æÆ÷µÍ×ֽڼĴæÆ÷Æ«ÒÆ
#define LS1C_I2C_PRER_HIGH_OFFSET           (1)     // ·ÖÆµËø´æÆ÷¸ß×ֽڼĴæÆ÷Æ«ÒÆ
#define LS1C_I2C_CONTROL_OFFSET             (2)     // ¿ØÖƼĴæÆ÷Æ«ÒÆ
#define LS1C_I2C_DATA_OFFSET                (3)     // ·¢ËÍÊý¾Ý¼Ä´æÆ÷ºÍ½ÓÊÕÊý¾Ý¼Ä´æÆ÷µÄÆ«ÒÆÊÇÏàͬµÄ
#define LS1C_I2C_CMD_OFFSET                 (4)     // ÃüÁî¼Ä´æÆ÷Æ«ÒÆ£¬Ö»Ð´
#define LS1C_I2C_STATUS_OFFSET              (4)     // ״̬¼Ä´æÆ÷Æ«ÒÆ£¬Ö»¶Á


// ¿ØÖƼĴæÆ÷µÄλÓò
#define LS1C_I2C_CONTROL_EN                 (0x80)  // i2cÄ£¿éʹÄÜ
#define LS1C_I2C_CONTROL_IEN                (0x40)  // ÖжÏʹÄÜ

// ÃüÁî¼Ä´æÆ÷µÄλÓò
#define LS1C_I2C_CMD_START                  (0x90)  // ²úÉúSTARTÐźÅ
#define LS1C_I2C_CMD_STOP                   (0x40)  // ²úÉúSTOPÐźÅ
#define LS1C_I2C_CMD_READ                   (0x20)  // ²úÉú¶ÁÐźţ¬¼´²úÉúACKÐźÅ
#define LS1C_I2C_CMD_WRITE                  (0x10)  // ²úÉúдÐźÅ
#define LS1C_I2C_CMD_READ_ACK               (0x20)  // ²úÉúACKÐźţ¬Óë¶ÁÐźÅÏàͬ
#define LS1C_I2C_CMD_READ_NACK              (0x28)  // ²úÉúNACKÐźÅ
#define LS1C_I2C_CMD_IACK                   (0x00)  // ²úÉúÖжÏÓ¦´ðÐźÅ

// ״̬¼Ä´æÆ÷µÄλÓò
#define LS1C_I2C_STATUS_IF                  (0x01)  // Öжϱê־λ
#define LS1C_I2C_STATUS_TIP                 (0x02)  // ָʾ´«ÊäµÄ¹ý³Ì¡£1£¬ÕýÔÚ´«Ê䣻0£¬´«ÊäÍê³É
#define LS1C_I2C_STATUS_ARBLOST             (0x20)  // I2CºËʧȥI2C×ÜÏߵĿØÖÆÈ¨
#define LS1C_I2C_STATUS_BUSY                (0x40)  // I2C×ÜÏßæ±êÖ¾
#define LS1C_I2C_STATUS_NACK                (0x80)  // Ó¦´ðλ±êÖ¾¡£1£¬Ã»ÊÕµ½Ó¦´ðλ£»0£¬ÊÕµ½Ó¦´ðλ


/*
 * »ñȡָ¶¨i2cÄ£¿éµÄ»ùµØÖ·
 * @I2Cx I2CÄ£¿éµÄ±àºÅ
 */
void *i2c_get_base(ls1c_i2c_t I2Cx)
{
    void *base = NULL;
    
    switch (I2Cx)
    {
        case LS1C_I2C_0:
            base = (void *)LS1C_I2C0_BASE;
            break;

        case LS1C_I2C_1:
            base = (void *)LS1C_I2C1_BASE;
            break;

        case LS1C_I2C_2:
            base = (void *)LS1C_I2C2_BASE;
            break;

        default:
            base = NULL;
            break;
    }

    return base;
}


/*
 * ÏòÃüÁî¼Ä´æÆ÷дÃüÁî
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @cmd ÃüÁî
 */
void i2c_cmd(ls1c_i2c_info_t *i2c_info_p, unsigned char cmd)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);

    reg_write_8(cmd, i2c_base + LS1C_I2C_CMD_OFFSET);

    return ;
}


/*
 * Ö´ÐÐSTARTÃüÁ·¢ËÍSTARTÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_start(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_START);
    return ;
}


/*
 * Ö´ÐÐSTOPÃüÁ·¢ËÍSTOPÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_stop(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_STOP);
    return ;
}


/*
 * Ö´ÐÐдÃüÁî
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_write(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_WRITE);
    return ;
}


/*
 * Ö´ÐжÁackÃüÁ·¢ËͶÁackÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_read_ack(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_READ_ACK);
    return ;
}


/*
 * Ö´ÐжÁnackÃüÁî,·¢ËͶÁnackÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_read_nack(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_READ_NACK);
    return ;
}


/*
 * ·¢ËÍÖжÏÓ¦´ðÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_cmd_iack(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_IACK);
    return ;
}


/*
 * »ñȡ״̬¼Ä´æÆ÷µÄÖµ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @ret ״̬¼Ä´æÆ÷µÄÖµ
 */
unsigned char i2c_get_status(ls1c_i2c_info_t *i2c_info_p)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);

    return reg_read_8(i2c_base + LS1C_I2C_STATUS_OFFSET);
}


/*
 * Poll the i2c status register until the specified bit is set.
 * Returns 0 if timed out (100 msec).
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @bit ¼Ä´æÆ÷µÄijһλ
 * @ret true or false
 */
int i2c_poll_status(ls1c_i2c_info_t *i2c_info_p, unsigned long bit)
{
    int loop_cntr = 20000;

    do {
        delay_us(1);
    } while ((i2c_get_status(i2c_info_p) & bit) && (0 < --loop_cntr));

    return (0 < loop_cntr);
}


/*
 * ³õʼ»¯Ö¸¶¨i2cÄ£¿é
 * @i2c_info_p ij¸öi2cÄ£¿éµÄÐÅÏ¢
 */
void i2c_init(ls1c_i2c_info_t *i2c_info_p)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
    unsigned long i2c_clock = i2c_info_p->clock;
    unsigned char ctrl = reg_read_8(i2c_base + LS1C_I2C_CONTROL_OFFSET);
    unsigned long prescale = 0;

    /* make sure the device is disabled */
    ctrl = ctrl & ~(LS1C_I2C_CONTROL_EN | LS1C_I2C_CONTROL_IEN);
    reg_write_8(ctrl, i2c_base + LS1C_I2C_CONTROL_OFFSET);

    // ÉèÖÃʱÖÓ
    i2c_clock = MIN(i2c_clock, LS1C_I2C_CLOCK_MAX);     // ÏÞÖÆÔÚ×î´óÔÊÐí·¶Î§ÄÚ
    prescale = clk_get_apb_rate();
    prescale = (prescale / (5 * i2c_clock)) - 1;
    reg_write_8(prescale & 0xff, i2c_base + LS1C_I2C_PRER_LOW_OFFSET);
    reg_write_8(prescale >> 8, i2c_base + LS1C_I2C_PRER_HIGH_OFFSET);
    
    // ʹÄÜ
    i2c_cmd_iack(i2c_info_p);
    ctrl = ctrl | LS1C_I2C_CONTROL_EN;
    reg_write_8(ctrl, i2c_base + LS1C_I2C_CONTROL_OFFSET);

    return ;
}


/*
 * (ÔÙ·¢ËÍÒ»¸ö×Ö½ÚÊý¾ÝÖ®ºó)½ÓÊÕ´Ó»ú·¢Ë͵ÄACKÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @ret LS1C_I2C_ACK or LS1C_I2C_NACK
 */
ls1c_i2c_ack_t i2c_receive_ack(ls1c_i2c_info_t *i2c_info_p)
{
    ls1c_i2c_ack_t ret = LS1C_I2C_NACK;
    
    if (LS1C_I2C_STATUS_NACK & i2c_get_status(i2c_info_p))
    {
        ret = LS1C_I2C_NACK;
    }
    else
    {
        ret = LS1C_I2C_ACK;
    }

    return ret;
}


/*
 * ½ÓÊÕÊý¾Ý
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @buf Êý¾Ý»º´æ
 * @len ´ý½ÓÊÕÊý¾ÝµÄ³¤¶È
 */
ls1c_i2c_ret_t i2c_receive_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *buf, int len)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
    int i = 0;

    for (i=0; i<len; i++)
    {
        // ¿ªÊ¼½ÓÊÕ
        if (i != (len - 1))
            i2c_cmd_read_ack(i2c_info_p);
        else 
            i2c_cmd_read_nack(i2c_info_p);

        // µÈ´ý£¬Ö±µ½½ÓÊÕÍê³É
        if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
            return LS1C_I2C_RET_TIMEOUT;

        // ¶ÁÈ¡Êý¾Ý£¬²¢±£´æ
        *buf++ = reg_read_8(i2c_base + LS1C_I2C_DATA_OFFSET);
    }

    return LS1C_I2C_RET_OK;
}


/*
 * ·¢ËÍSTARTÐźź͵ØÖ·
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @slave_addr ´Ó»úµØÖ·
 * @direction Êý¾Ý´«Êä·½Ïò(¶Á¡¢Ð´)
 */
ls1c_i2c_ret_t i2c_send_start_and_addr(ls1c_i2c_info_t *i2c_info_p, 
                                       unsigned char slave_addr,
                                       ls1c_i2c_direction_t direction)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
    unsigned char data = 0;
    
    // µÈ´ýi2c×ÜÏß¿ÕÏÐ
    if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_BUSY))
        return LS1C_I2C_RET_TIMEOUT;

    // Ìî³äµØÖ·µ½Êý¾Ý¼Ä´æÆ÷
    data = (slave_addr << 1) | ((LS1C_I2C_DIRECTION_READ == direction) ? 1 : 0);
    reg_write_8(data , i2c_base + LS1C_I2C_DATA_OFFSET);

    // ¿ªÊ¼·¢ËÍ
    i2c_cmd_start(i2c_info_p);

    // µÈ´ý£¬Ö±µ½·¢ËÍÍê³É
    if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
        return LS1C_I2C_RET_TIMEOUT;

    return LS1C_I2C_RET_OK;
}


/*
 * ·¢ËÍÊý¾Ý
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 * @data ´ý·¢Ë͵ÄÊý¾Ý
 * @len ´ý·¢ËÍÊý¾ÝµÄ³¤¶È
 */
ls1c_i2c_ret_t i2c_send_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *data, int len)
{
    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
    int i = 0;

    for (i=0; i<len; i++)
    {
        // ½«Ò»¸ö×Ö½ÚÊý¾ÝдÈëÊý¾Ý¼Ä´æÆ÷
        reg_write_8(*data++, i2c_base + LS1C_I2C_DATA_OFFSET);

        // ¿ªÊ¼·¢ËÍ
        reg_write_8(LS1C_I2C_CMD_WRITE, i2c_base + LS1C_I2C_CMD_OFFSET);

        // µÈ´ý£¬Ö±µ½·¢ËÍÍê³É
        if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
            return LS1C_I2C_RET_TIMEOUT;

        // ¶ÁȡӦ´ðÐźÅ
        if (LS1C_I2C_ACK != i2c_receive_ack(i2c_info_p))
            return len;
    }

    return LS1C_I2C_RET_OK;
}



/*
 * ·¢ËÍSTOPÐźÅ
 * @i2c_info_p i2cÄ£¿éÐÅÏ¢
 */
void i2c_send_stop(ls1c_i2c_info_t *i2c_info_p)
{
    i2c_cmd_stop(i2c_info_p);
    return ;
}