223 lines
6.9 KiB
C
223 lines
6.9 KiB
C
/* ------------------------------------------------------------------------- */
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/* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters */
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/* ------------------------------------------------------------------------- */
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/* Copyright (C) 2001,2002,2003 Broadcom Corporation
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Copyright (C) 1995-2000 Simon G. Vogl
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/* ------------------------------------------------------------------------- */
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/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
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Frodo Looijaard <frodol@dds.nl>. */
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/* Ported for SiByte SOCs by Broadcom Corporation. */
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <asm/sibyte/sb1250_regs.h>
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#include <asm/sibyte/sb1250_smbus.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-sibyte.h>
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/* ----- global defines ----------------------------------------------- */
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#define SMB_CSR(a,r) ((long)(a->reg_base + r))
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/* ----- global variables --------------------------------------------- */
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/* module parameters:
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*/
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static int bit_scan=0; /* have a look at what's hanging 'round */
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static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
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unsigned short flags, char read_write,
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u8 command, int size, union i2c_smbus_data * data)
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{
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struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
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int data_bytes = 0;
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int error;
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while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
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;
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switch (size) {
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case I2C_SMBUS_QUICK:
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csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
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V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
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break;
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case I2C_SMBUS_BYTE:
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if (read_write == I2C_SMBUS_READ) {
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
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SMB_CSR(adap, R_SMB_START));
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data_bytes = 1;
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} else {
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csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
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SMB_CSR(adap, R_SMB_START));
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}
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break;
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case I2C_SMBUS_BYTE_DATA:
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csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
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if (read_write == I2C_SMBUS_READ) {
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
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SMB_CSR(adap, R_SMB_START));
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data_bytes = 1;
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} else {
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csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
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SMB_CSR(adap, R_SMB_START));
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}
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break;
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case I2C_SMBUS_WORD_DATA:
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csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
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if (read_write == I2C_SMBUS_READ) {
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
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SMB_CSR(adap, R_SMB_START));
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data_bytes = 2;
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} else {
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csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
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csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
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csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
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SMB_CSR(adap, R_SMB_START));
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}
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break;
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default:
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return -1; /* XXXKW better error code? */
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}
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while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
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;
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error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
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if (error & M_SMB_ERROR) {
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/* Clear error bit by writing a 1 */
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csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
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return -1; /* XXXKW better error code? */
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}
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if (data_bytes == 1)
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data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
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if (data_bytes == 2)
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data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
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return 0;
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}
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static int algo_control(struct i2c_adapter *adapter,
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unsigned int cmd, unsigned long arg)
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{
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return 0;
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}
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static u32 bit_func(struct i2c_adapter *adap)
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{
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return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
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}
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/* -----exported algorithm data: ------------------------------------- */
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static struct i2c_algorithm i2c_sibyte_algo = {
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.name = "SiByte algorithm",
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.id = I2C_ALGO_SIBYTE,
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.smbus_xfer = smbus_xfer,
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.algo_control = algo_control, /* ioctl */
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.functionality = bit_func,
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};
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/*
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* registering functions to load algorithms at runtime
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*/
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int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
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{
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int i;
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struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
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/* register new adapter to i2c module... */
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i2c_adap->id |= i2c_sibyte_algo.id;
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i2c_adap->algo = &i2c_sibyte_algo;
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/* Set the frequency to 100 kHz */
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csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
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csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
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/* scan bus */
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if (bit_scan) {
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union i2c_smbus_data data;
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int rc;
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printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
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i2c_adap->name);
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for (i = 0x00; i < 0x7f; i++) {
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/* XXXKW is this a realistic probe? */
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rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
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I2C_SMBUS_BYTE_DATA, &data);
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if (!rc) {
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printk("(%02x)",i);
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} else
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printk(".");
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}
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printk("\n");
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}
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i2c_add_adapter(i2c_adap);
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return 0;
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}
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int i2c_sibyte_del_bus(struct i2c_adapter *adap)
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{
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int res;
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if ((res = i2c_del_adapter(adap)) < 0)
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return res;
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return 0;
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}
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int __init i2c_algo_sibyte_init (void)
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{
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printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n");
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return 0;
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}
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EXPORT_SYMBOL(i2c_sibyte_add_bus);
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EXPORT_SYMBOL(i2c_sibyte_del_bus);
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#ifdef MODULE
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MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
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MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
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MODULE_PARM(bit_scan, "i");
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MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
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MODULE_LICENSE("GPL");
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int init_module(void)
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{
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return i2c_algo_sibyte_init();
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}
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void cleanup_module(void)
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{
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}
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#endif
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