u-boot/drivers/tsi108_i2c.c
2007-03-04 01:36:05 +01:00

284 lines
7.8 KiB
C

/*
* (C) Copyright 2004 Tundra Semiconductor Corp.
* Author: Alex Bounine
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <config.h>
#include <common.h>
#ifdef CONFIG_TSI108_I2C
#include <tsi108.h>
#if (CONFIG_COMMANDS & CFG_CMD_I2C)
#define I2C_DELAY 100000
#undef DEBUG_I2C
#ifdef DEBUG_I2C
#define DPRINT(x) printf (x)
#else
#define DPRINT(x)
#endif
/* All functions assume that Tsi108 I2C block is the only master on the bus */
/* I2C read helper function */
static int i2c_read_byte (
uint i2c_chan, /* I2C channel number: 0 - main, 1 - SDC SPD */
uchar chip_addr,/* I2C device address on the bus */
uint byte_addr, /* Byte address within I2C device */
uchar * buffer /* pointer to data buffer */
)
{
u32 temp;
u32 to_count = I2C_DELAY;
u32 op_status = TSI108_I2C_TIMEOUT_ERR;
u32 chan_offset = TSI108_I2C_OFFSET;
DPRINT (("I2C read_byte() %d 0x%02x 0x%02x\n",
i2c_chan, chip_addr, byte_addr));
if (0 != i2c_chan)
chan_offset = TSI108_I2C_SDRAM_OFFSET;
/* Check if I2C operation is in progress */
temp = *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
I2C_CNTRL2_START))) {
/* Set device address and operation (read = 0) */
temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
((chip_addr >> 3) & 0x0F);
*(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
temp;
/* Issue the read command
* (at this moment all other parameters are 0
* (size = 1 byte, lane = 0)
*/
*(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
(I2C_CNTRL2_START);
/* Wait until operation completed */
do {
/* Read I2C operation status */
temp = *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START))) {
if (0 == (temp &
(I2C_CNTRL2_I2C_CFGERR |
I2C_CNTRL2_I2C_TO_ERR))
) {
op_status = TSI108_I2C_SUCCESS;
temp = *(u32 *) (CFG_TSI108_CSR_BASE +
chan_offset +
I2C_RD_DATA);
*buffer = (u8) (temp & 0xFF);
} else {
/* report HW error */
op_status = TSI108_I2C_IF_ERROR;
DPRINT (("I2C HW error reported: 0x%02x\n", temp));
}
break;
}
} while (to_count--);
} else {
op_status = TSI108_I2C_IF_BUSY;
DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
}
DPRINT (("I2C read_byte() status: 0x%02x\n", op_status));
return op_status;
}
/*
* I2C Read interface as defined in "include/i2c.h" :
* chip_addr: I2C chip address, range 0..127
* (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
* NOTE: The bit 7 in the chip_addr serves as a channel select.
* This hack is for enabling "isdram" command on Tsi108 boards
* without changes to common code. Used for I2C reads only.
* byte_addr: Memory or 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)
* buffer: Pointer to destination buffer for data to be read
* len: How many bytes to read
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_read (uchar chip_addr, uint byte_addr, int alen,
uchar * buffer, int len)
{
u32 op_status = TSI108_I2C_PARAM_ERR;
u32 i2c_if = 0;
/* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
if (0xD0 == (chip_addr & ~0x07)) {
i2c_if = 1;
chip_addr &= 0x7F;
}
/* Check for valid I2C address */
if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
while (len--) {
op_status = i2c_read_byte(i2c_if, chip_addr, byte_addr++, buffer++);
if (TSI108_I2C_SUCCESS != op_status) {
DPRINT (("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
break;
}
}
}
DPRINT (("I2C read() status: 0x%02x\n", op_status));
return op_status;
}
/* I2C write helper function */
static int i2c_write_byte (uchar chip_addr,/* I2C device address on the bus */
uint byte_addr, /* Byte address within I2C device */
uchar * buffer /* pointer to data buffer */
)
{
u32 temp;
u32 to_count = I2C_DELAY;
u32 op_status = TSI108_I2C_TIMEOUT_ERR;
/* Check if I2C operation is in progress */
temp = *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
/* Place data into the I2C Tx Register */
*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
I2C_TX_DATA) = (u32) * buffer;
/* Set device address and operation */
temp =
I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
I2C_CNTRL1) = temp;
/* Issue the write command (at this moment all other parameters
* are 0 (size = 1 byte, lane = 0)
*/
*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
I2C_CNTRL2) = (I2C_CNTRL2_START);
op_status = TSI108_I2C_TIMEOUT_ERR;
/* Wait until operation completed */
do {
/* Read I2C operation status */
temp = *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
if (0 == (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
if (0 == (temp &
(I2C_CNTRL2_I2C_CFGERR |
I2C_CNTRL2_I2C_TO_ERR))) {
op_status = TSI108_I2C_SUCCESS;
} else {
/* report detected HW error */
op_status = TSI108_I2C_IF_ERROR;
DPRINT (("I2C HW error reported: 0x%02x\n", temp));
}
break;
}
} while (to_count--);
} else {
op_status = TSI108_I2C_IF_BUSY;
DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
}
return op_status;
}
/*
* I2C Write interface as defined in "include/i2c.h" :
* chip_addr: I2C chip address, range 0..127
* byte_addr: Memory or 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)
* buffer: Pointer to data to be written
* len: How many bytes to write
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_write (uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
int len)
{
u32 op_status = TSI108_I2C_PARAM_ERR;
/* Check for valid I2C address */
if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
while (len--) {
op_status =
i2c_write_byte (chip_addr, byte_addr++, buffer++);
if (TSI108_I2C_SUCCESS != op_status) {
DPRINT (("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
break;
}
}
}
return op_status;
}
/*
* I2C interface function as defined in "include/i2c.h".
* Probe the given I2C chip address by reading single byte from offset 0.
* Returns 0 if a chip responded, not 0 on failure.
*/
int i2c_probe (uchar chip)
{
u32 tmp;
/*
* Try to read the first location of the chip.
* The Tsi108 HW doesn't support sending just the chip address
* and checkong for an <ACK> back.
*/
return i2c_read (chip, 0, 1, (char *)&tmp, 1);
}
#endif /* (CONFIG_COMMANDS & CFG_CMD_I2C) */
#endif /* CONFIG_TSI108_I2C */