int early_i2c_read (u8 dev, uint addr, int alen, u8 * data, int length)
{
int i = 0;
u8 *a = (u8 *) & addr;
/* wait while i2c bus is busy */
if (i2c_wait4bus () < 0)
goto exit;
/* transmite the slave_addr+read/write phase */
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
/* select the i2c slave internal regs phase */
/* because u32 -> u8, and big endian, so if alen is 1, write a[3] */
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
/* dummy read phase */
if (i2c_write_addr (dev, I2C_READ, 1) == 0)
goto exit;
/* transmite data phase */
i = __i2c_read (data, length);
exit:
writel (M83xx_CCR_MEN, I2CCCR);
return !(i == length);
}
/*
* Internal simplified write function:
* i2c_regs: Pointer to I2C registers for current bus
* chip: I2C chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (typically 1, 2 for larger
* memories, 0 for register type devices with only one register)
* data: Where to read the data
* len: How many bytes to write
*
* Returns: 0 on success, not 0 on failure
*/
static int __i2c_write(struct u5500_i2c_regs *i2c_regs, u8 chip, uint addr,
int alen, u8 *data, int len)
{
int i;
u32 mcr = 0;
/* Set the address mode to 7 bit */
WRITE_FIELD(mcr, I2C_MCR_AM, I2C_MCR_SHIFT_AM, 1);
/* Store the slave address in the master control register */
WRITE_FIELD(mcr, I2C_MCR_A7, I2C_MCR_SHIFT_A7, chip);
/* Write operation */
CLR_BIT(mcr, I2C_MCR_OP);
/* Current transaction is terminated by STOP condition */
SET_BIT(mcr, I2C_MCR_STOP);
/* Frame length: addr byte + len */
WRITE_FIELD(mcr, I2C_MCR_LENGTH, I2C_MCR_SHIFT_LENGTH, (alen + len));
/* Write MCR register */
writel(mcr, &i2c_regs->mcr);
if (i2c_write_addr(i2c_regs, addr, alen) != 0)
return -1;
for (i = 0; i < len; i++) {
/* Wait until the Tx FIFO is not full */
if (loop_till_bit_clear((void *)&i2c_regs->risr,
I2C_INT_TXFF, I2C_ENDAD_COUNTER))
return -1;
/* it is a 32 bit register with upper 24 reserved R/O */
writeb(data[i], &i2c_regs->tfr);
}
/* Check for Master Transaction Done */
if (loop_till_bit_set((void *)&i2c_regs->risr, I2C_INT_MTD,
I2C_ENDAD_COUNTER)) {
printf("i2c_write_byte error2: risr %08x\n",
i2c_regs->risr);
return -1;
}
/* Acknowledge Master Transaction Done */
i2c_set_bit(&i2c_regs->icr, I2C_INT_MTD);
/* Acknowledge Master Transaction Done Without Stop */
i2c_set_bit(&i2c_regs->icr, I2C_INT_MTDWS);
return 0;
}
int
i2c_read (u8 dev, uint addr, int alen, u8 *data, int length)
{
int i = 0;
u8 *a = (u8*)&addr;
if (i2c_wait4bus () < 0)
goto exit;
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
if (i2c_write_addr (dev, I2C_READ, 1) == 0)
goto exit;
i = __i2c_read (data, length);
exit:
writeb(I2C_CR_MEN, &I2C->cr);
return !(i == length);
}
/*
* Internal simplified read function:
* i2c_regs: Pointer to I2C registers for current bus
* chip: I2C chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (typically 1, 2 for larger
* memories, 0 for register type devices with only one register)
* value: Where to put the data
*
* Returns: 0 on success, not 0 on failure
*/
static int i2c_read_byte(struct u5500_i2c_regs *i2c_regs, uchar chip,
uint addr, int alen, uchar *value)
{
u32 mcr = 0;
/* Set the address mode to 7 bit */
WRITE_FIELD(mcr, I2C_MCR_AM, I2C_MCR_SHIFT_AM, 1);
/* Store the slave address in the master control register */
WRITE_FIELD(mcr, I2C_MCR_A7, I2C_MCR_SHIFT_A7, chip);
if (alen != 0) {
/* Master write operation */
CLR_BIT(mcr, I2C_MCR_OP);
/* Configure the Frame length to one byte */
WRITE_FIELD(mcr, I2C_MCR_LENGTH, I2C_MCR_SHIFT_LENGTH, 1);
/* Repeated start, no stop */
CLR_BIT(mcr, I2C_MCR_STOP);
/* Write Master Control Register */
writel(mcr, &i2c_regs->mcr);
/* send addr/index */
if (i2c_write_addr(i2c_regs, addr, alen) != 0)
return -1;
/* Check for the Master Transaction Done Without Stop */
if (loop_till_bit_set((void *)&i2c_regs->risr,
I2C_INT_MTDWS, I2C_ENDAD_COUNTER)) {
return -1;
}
/* Acknowledge the Master Transaction Done Without Stop */
i2c_set_bit(&i2c_regs->icr, I2C_INT_MTDWS);
}
/* Master control configuration for read operation */
SET_BIT(mcr, I2C_MCR_OP);
/* Configure the STOP condition, we read only one byte */
SET_BIT(mcr, I2C_MCR_STOP);
/* Set the frame length to one byte, we support only 1 byte reads */
WRITE_FIELD(mcr, I2C_MCR_LENGTH, I2C_MCR_SHIFT_LENGTH, 1);
i2c_write_field(&i2c_regs->mcr, I2C_MCR_LENGTH_STOP_OP,
I2C_MCR_SHIFT_LENGTH_STOP_OP, mcr);
/*
* receive_data_polling
*/
/* Wait until the Rx FIFO is not empty */
if (loop_till_bit_clear((void *)&i2c_regs->risr, I2C_INT_RXFE,
I2C_ENDAD_COUNTER))
return -1;
/* Read the data byte from Rx FIFO */
*value = readb(&i2c_regs->rfr);
/* Wait until the work is done */
if (loop_till_bit_set((void *)&i2c_regs->risr, I2C_INT_MTD,
I2C_ENDAD_COUNTER))
return -1;
/* Acknowledge the Master Transaction Done */
i2c_set_bit(&i2c_regs->icr, I2C_INT_MTD);
/* If MTD is set, Master Transaction Done Without Stop is set too */
i2c_set_bit(&i2c_regs->icr, I2C_INT_MTDWS);
return 0;
}