BCM_I2C函数更改

版本：sdk-xgs-robo-6.3.8
平台：BCM53344
应用：控制POE芯片

描述：POE控制芯片使用PD69200，使用i2c与其通信，每次需要发送15字节数据，并接受15字节的返回数据。

1.更改函数

打开文件sdk-xgs-robo-6.3.8/src/soc/i2c/smbus.c
更改如下：
int
soc_i2c_block_read(int unit, i2c_saddr_t saddr,
           uint8 com, uint8* count, uint8* data)
{
     //... 省略 ...

    I2C_LOCK(unit);
// 53344芯片在定义了BCM_CMICM_SUPPORT,所以会运行下面的代码。
#ifdef BCM_CMICM_SUPPORT
    if(soc_feature(unit, soc_feature_cmicm) && !SOC_IS_SAND(unit)) {
retry:
　　//这个函数是smbus协议的命令格式。与I2C有些区别。注释掉发送地址和com的地方。
　　//直接读取数据
//        rval = SOC_I2C_TX_ADDR(saddr);
//        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
//        rval = com;
//        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
        rval = SOC_I2C_RX_ADDR(saddr);
        soc_reg_field_set(unit, CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr, &rval, MASTER_WR_STATUSf, 1); /* Last Byte */
        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
　　　　//更改要接受的数据个数。默认是0，因此会读取0个数据。
　　　　//查看芯片手册，需要将CMIC_I2CM_SMBus_Master_Command寄存器的最低8位（RD_BYTE_COUNT),设置为要读取的字节个数。
//        rval = 0;
        rval = *count;
        soc_reg_field_set(unit, CMIC_I2CM_SMBUS_MASTER_COMMANDr, &rval, SMBUS_PROTOCOLf, SMBUS_BLOCK_READ);
        WRITE_CMIC_I2CM_SMBUS_MASTER_COMMANDr(unit,rval);

        rv = smbus_start_wait(unit);
        if (rv == SOC_E_NONE) {
　　　　//直接读取即可，这一部分也不需要，smbus协议才需要
//            READ_CMIC_I2CM_SMBUS_MASTER_DATA_READr(unit, &rval);
//            *count = (uint8) (rval & 0xff);
            ptr = data;
            for( i = 0; i < *count; i++, ptr++) {
                READ_CMIC_I2CM_SMBUS_MASTER_DATA_READr(unit, &rval);
                *ptr = (uint8) (rval & 0xff);
            }
        } else if (rt-- > 0) {
            goto retry;
        } else {
            rv = SOC_E_TIMEOUT;
        }
    } else　　//后面的不运行
#endif
　　// ... 省略 ...
}

//同理，write函数也进行注释
int
soc_i2c_block_write(int unit, i2c_saddr_t saddr,
            uint8 com, uint8 count, uint8* data)
{
    int i,rv = SOC_E_NONE;
    uint8* ptr = NULL;
#ifdef BCM_CMICM_SUPPORT
    uint32 rval;
    int rt = 5;
#endif

soc_cm_debug(DK_I2C, "i2c%d: soc_i2c_block_write %02x bytes @ %02x - %02x
", unit, count, saddr, com);

#ifdef BCM_CALADAN3_SVK
    if (unit == -1) {
        return cpu_i2c_block_write(unit, saddr, com, data, count);
    }
#endif

    I2C_LOCK(unit);
#ifdef BCM_CMICM_SUPPORT
    if(soc_feature(unit, soc_feature_cmicm) && !SOC_IS_SAND(unit)) {
retry:
        rval = SOC_I2C_TX_ADDR(saddr);
        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
//        rval = com;
//        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
//        rval = count;
//        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);

        ptr = data;
        for( i = 0; i < (int) (count - 1); i++, ptr++) {
            rval = (uint32) *ptr;
            WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);
        }
        rval = (uint32) *ptr;
        soc_reg_field_set(unit, CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr, &rval, MASTER_WR_STATUSf, 1); /* Last Byte */
        WRITE_CMIC_I2CM_SMBUS_MASTER_DATA_WRITEr(unit, rval);

        rval = 0;
        soc_reg_field_set(unit, CMIC_I2CM_SMBUS_MASTER_COMMANDr, &rval, SMBUS_PROTOCOLf, SMBUS_BLOCK_WRITE);
        WRITE_CMIC_I2CM_SMBUS_MASTER_COMMANDr(unit,rval);

        rv = smbus_start_wait(unit);
        if (rv != SOC_E_NONE && rt-- > 0) {
            goto retry;
        } else if (rt < 0) {
            rv = SOC_E_TIMEOUT;
        }
    } else
#endif

2.导出全局符号
打开文件 sdk/systems/linux/kernel/modules/include/bcmx_export.h
最后添加：
　　#include <soc/i2c.h>
　　EXPORT_SYMBOL(soc_i2c_is_attached);
　　EXPORT_SYMBOL(soc_i2c_attach);
　　EXPORT_SYMBOL(soc_i2c_block_read);
　　EXPORT_SYMBOL(soc_i2c_block_write);

之后从新编译SDK即可。