/*
****************************************************************************************************
*
* i2c_read
*
* Description:
*
*
* Parameters:
*
* Return value:
*
* Read/Write interface:
* bus_id: the id of the twi bus: 4,3,2,1,0 is to twi4..twi0
* chip: I2C slave chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (
* 0, 1: addr len = 8bit
* 2: addr len = 16bit
* 3, 4: addr len = 32bit
*
* buffer: Where to read/write the data
* len: How many bytes to read/write
*
* Returns: 0 on success, not 0 on failure
*
****************************************************************************************************
*/
int i2c_read(uint bus_id, uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i, ret, ret0, addrlen;
char *slave_reg;
uint twi_host = 0;
ret0 = -1;
if(bus_id < SUNXI_TWI_COUNT)
{
twi_host = SUNXI_TWI0_BASE + SUNXI_TWI_OFFSET * bus_id;
}
else
{
printf("i2c bus id %d is error\n", bus_id);
return ret0;
}
ret = i2c_sendstart(twi_host);
if(ret)
{
goto i2c_read_err_occur;
}
ret = i2c_sendslaveaddr(twi_host, chip, I2C_WRITE);
if(ret)
{
goto i2c_read_err_occur;
}
//send byte address
if(alen >= 3)
{
addrlen = 2;
}
else if(alen <= 1)
{
addrlen = 0;
}
else
{
addrlen = 1;
}
slave_reg = (char *)&addr;
for (i = addrlen; i>=0; i--)
{
ret = i2c_sendbyteaddr(twi_host, slave_reg[i] & 0xff);
if(ret)
{
goto i2c_read_err_occur;
}
}
ret = i2c_sendRestart(twi_host);
if(ret)
{
goto i2c_read_err_occur;
}
ret = i2c_sendslaveaddr(twi_host, chip, I2C_READ);
if(ret)
{
goto i2c_read_err_occur;
}
//get data
ret = i2c_getdata(twi_host, buffer, len);
if(ret)
{
goto i2c_read_err_occur;
}
ret0 = 0;
i2c_read_err_occur:
i2c_stop(twi_host);
return ret0;
}
/*
**********************************************************************************************************************
* i2c_init
*
* Description:
*
* Arguments :
*
* Returns : none
*
* Notes : none
*
**********************************************************************************************************************
*/
void i2c_exit(void)
{
#ifndef CONFIG_CPUS_I2C
int reg_value = 0;
reg_value = readl(CCMU_BUS_CLK_GATING_REG3);
reg_value &= ~(1<<bus_num);
writel(reg_value,CCMU_BUS_CLK_GATING_REG3);
#else
int reg_value = 0;
reg_value = *((unsigned int *)(R_PRCE_APB0_RESET));
reg_value &= ~(0x01 << 6);
*((unsigned int *)(R_PRCE_APB0_RESET)) = reg_value;
__msdelay(1);
reg_value = *((unsigned int *)(R_PRCM_APB0_GATING));
reg_value &= ~(0x01 << 6);
*((unsigned int *)(R_PRCM_APB0_GATING)) = reg_value;
__msdelay(1);
#endif
return ;
}/*
****************************************************************************************************
*
* i2c_read
*
* Description:
*
*
* Parameters:
*
* Return value:
*
* Read/Write interface:
* chip: I2C slave chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (
* 0, 1: addr len = 8bit
* 2: addr len = 16bit
* 3, 4: addr len = 32bit
*
* buffer: Where to read/write the data
* len: How many bytes to read/write
*
* Returns: 0 on success, not 0 on failure
*
****************************************************************************************************
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i, ret, ret0, addrlen;
char *slave_reg;
ret0 = -1;
ret = i2c_sendstart();
if(ret)
{
goto i2c_read_err_occur;
}
ret = i2c_sendslaveaddr(chip, I2C_WRITE);
if(ret)
{
goto i2c_read_err_occur;
}
//send byte address
if(alen >= 3)
{
addrlen = 2;
}
else if(alen <= 1)
{
addrlen = 0;
}
else
{
addrlen = 1;
}
slave_reg = (char *)&addr;
for (i = addrlen; i>=0; i--)
{
ret = i2c_sendbyteaddr(slave_reg[i] & 0xff);
if(ret)
{
goto i2c_read_err_occur;
}
}
ret = i2c_sendRestart();
if(ret)
{
goto i2c_read_err_occur;
}
ret = i2c_sendslaveaddr(chip, I2C_READ);
if(ret)
{
goto i2c_read_err_occur;
}
//get data
ret = i2c_getdata(buffer, len);
if(ret)
{
goto i2c_read_err_occur;
}
ret0 = 0;
i2c_read_err_occur:
i2c_stop();
return ret0;
}
