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/* ------------------------------------------------------------------------- */
/* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 2001,2002,2003 Broadcom Corporation
Copyright (C) 1995-2000 Simon G. Vogl
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
Frodo Looijaard <frodol@dds.nl>. */
/* Ported for SiByte SOCs by Broadcom Corporation. */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_smbus.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-sibyte.h>
/* ----- global defines ----------------------------------------------- */
#define SMB_CSR(a,r) ((long)(a->reg_base + r))
/* ----- global variables --------------------------------------------- */
/* module parameters:
*/
static int bit_scan; /* have a look at what's hanging 'round */
static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data * data)
{
struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
int data_bytes = 0;
int error;
while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
;
switch (size) {
case I2C_SMBUS_QUICK:
csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_READ) {
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
SMB_CSR(adap, R_SMB_START));
data_bytes = 1;
} else {
csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
SMB_CSR(adap, R_SMB_START));
}
break;
case I2C_SMBUS_BYTE_DATA:
csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
if (read_write == I2C_SMBUS_READ) {
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
SMB_CSR(adap, R_SMB_START));
data_bytes = 1;
} else {
csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
SMB_CSR(adap, R_SMB_START));
}
break;
case I2C_SMBUS_WORD_DATA:
csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
if (read_write == I2C_SMBUS_READ) {
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
SMB_CSR(adap, R_SMB_START));
data_bytes = 2;
} else {
csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
SMB_CSR(adap, R_SMB_START));
}
break;
default:
return -1; /* XXXKW better error code? */
}
while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
;
error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
if (error & M_SMB_ERROR) {
/* Clear error bit by writing a 1 */
csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
return -1; /* XXXKW better error code? */
}
if (data_bytes == 1)
data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
if (data_bytes == 2)
data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
return 0;
}
static u32 bit_func(struct i2c_adapter *adap)
{
return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
}
/* -----exported algorithm data: ------------------------------------- */
static struct i2c_algorithm i2c_sibyte_algo = {
.smbus_xfer = smbus_xfer,
.functionality = bit_func,
};
/*
* registering functions to load algorithms at runtime
*/
int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
{
int i;
struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
/* register new adapter to i2c module... */
i2c_adap->algo = &i2c_sibyte_algo;
/* Set the frequency to 100 kHz */
csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
/* scan bus */
if (bit_scan) {
union i2c_smbus_data data;
int rc;
printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
i2c_adap->name);
for (i = 0x00; i < 0x7f; i++) {
/* XXXKW is this a realistic probe? */
rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
I2C_SMBUS_BYTE_DATA, &data);
if (!rc) {
printk("(%02x)",i);
} else
printk(".");
}
printk("\n");
}
return i2c_add_adapter(i2c_adap);
}
int i2c_sibyte_del_bus(struct i2c_adapter *adap)
{
return i2c_del_adapter(adap);
}
EXPORT_SYMBOL(i2c_sibyte_add_bus);
EXPORT_SYMBOL(i2c_sibyte_del_bus);
MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
module_param(bit_scan, int, 0);
MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
MODULE_LICENSE("GPL");
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