/drivers/i2c/algos/i2c-algo-sibyte.c
C | 222 lines | 148 code | 38 blank | 36 comment | 23 complexity | b72b1c8b8b1e84e2f2773d54dd86cb8e MD5 | raw file
1/* ------------------------------------------------------------------------- */ 2/* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters */ 3/* ------------------------------------------------------------------------- */ 4/* Copyright (C) 2001,2002,2003 Broadcom Corporation 5 Copyright (C) 1995-2000 Simon G. Vogl 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ 20/* ------------------------------------------------------------------------- */ 21 22/* With some changes from Ky�sti M�lkki <kmalkki@cc.hut.fi> and even 23 Frodo Looijaard <frodol@dds.nl>. */ 24 25/* Ported for SiByte SOCs by Broadcom Corporation. */ 26 27#include <linux/config.h> 28#include <linux/kernel.h> 29#include <linux/module.h> 30#include <linux/init.h> 31 32#include <asm/io.h> 33#include <asm/sibyte/sb1250_regs.h> 34#include <asm/sibyte/sb1250_smbus.h> 35 36#include <linux/i2c.h> 37#include <linux/i2c-algo-sibyte.h> 38 39/* ----- global defines ----------------------------------------------- */ 40#define SMB_CSR(a,r) ((long)(a->reg_base + r)) 41 42/* ----- global variables --------------------------------------------- */ 43 44/* module parameters: 45 */ 46static int bit_scan=0; /* have a look at what's hanging 'round */ 47 48 49static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, 50 unsigned short flags, char read_write, 51 u8 command, int size, union i2c_smbus_data * data) 52{ 53 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 54 int data_bytes = 0; 55 int error; 56 57 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 58 ; 59 60 switch (size) { 61 case I2C_SMBUS_QUICK: 62 csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) | 63 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START)); 64 break; 65 case I2C_SMBUS_BYTE: 66 if (read_write == I2C_SMBUS_READ) { 67 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE), 68 SMB_CSR(adap, R_SMB_START)); 69 data_bytes = 1; 70 } else { 71 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 72 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE), 73 SMB_CSR(adap, R_SMB_START)); 74 } 75 break; 76 case I2C_SMBUS_BYTE_DATA: 77 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 78 if (read_write == I2C_SMBUS_READ) { 79 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE), 80 SMB_CSR(adap, R_SMB_START)); 81 data_bytes = 1; 82 } else { 83 csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA)); 84 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 85 SMB_CSR(adap, R_SMB_START)); 86 } 87 break; 88 case I2C_SMBUS_WORD_DATA: 89 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 90 if (read_write == I2C_SMBUS_READ) { 91 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE), 92 SMB_CSR(adap, R_SMB_START)); 93 data_bytes = 2; 94 } else { 95 csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA)); 96 csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA)); 97 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 98 SMB_CSR(adap, R_SMB_START)); 99 } 100 break; 101 default: 102 return -1; /* XXXKW better error code? */ 103 } 104 105 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 106 ; 107 108 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS)); 109 if (error & M_SMB_ERROR) { 110 /* Clear error bit by writing a 1 */ 111 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS)); 112 return -1; /* XXXKW better error code? */ 113 } 114 115 if (data_bytes == 1) 116 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff; 117 if (data_bytes == 2) 118 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff; 119 120 return 0; 121} 122 123static int algo_control(struct i2c_adapter *adapter, 124 unsigned int cmd, unsigned long arg) 125{ 126 return 0; 127} 128 129static u32 bit_func(struct i2c_adapter *adap) 130{ 131 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 132 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA); 133} 134 135 136/* -----exported algorithm data: ------------------------------------- */ 137 138static struct i2c_algorithm i2c_sibyte_algo = { 139 .name = "SiByte algorithm", 140 .id = I2C_ALGO_SIBYTE, 141 .smbus_xfer = smbus_xfer, 142 .algo_control = algo_control, /* ioctl */ 143 .functionality = bit_func, 144}; 145 146/* 147 * registering functions to load algorithms at runtime 148 */ 149int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed) 150{ 151 int i; 152 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 153 154 /* register new adapter to i2c module... */ 155 156 i2c_adap->id |= i2c_sibyte_algo.id; 157 i2c_adap->algo = &i2c_sibyte_algo; 158 159 /* Set the frequency to 100 kHz */ 160 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ)); 161 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL)); 162 163 /* scan bus */ 164 if (bit_scan) { 165 union i2c_smbus_data data; 166 int rc; 167 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n", 168 i2c_adap->name); 169 for (i = 0x00; i < 0x7f; i++) { 170 /* XXXKW is this a realistic probe? */ 171 rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0, 172 I2C_SMBUS_BYTE_DATA, &data); 173 if (!rc) { 174 printk("(%02x)",i); 175 } else 176 printk("."); 177 } 178 printk("\n"); 179 } 180 181 i2c_add_adapter(i2c_adap); 182 183 return 0; 184} 185 186 187int i2c_sibyte_del_bus(struct i2c_adapter *adap) 188{ 189 int res; 190 191 if ((res = i2c_del_adapter(adap)) < 0) 192 return res; 193 194 return 0; 195} 196 197int __init i2c_algo_sibyte_init (void) 198{ 199 printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n"); 200 return 0; 201} 202 203 204EXPORT_SYMBOL(i2c_sibyte_add_bus); 205EXPORT_SYMBOL(i2c_sibyte_del_bus); 206 207#ifdef MODULE 208MODULE_AUTHOR("Kip Walker, Broadcom Corp."); 209MODULE_DESCRIPTION("SiByte I2C-Bus algorithm"); 210MODULE_PARM(bit_scan, "i"); 211MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus"); 212MODULE_LICENSE("GPL"); 213 214int init_module(void) 215{ 216 return i2c_algo_sibyte_init(); 217} 218 219void cleanup_module(void) 220{ 221} 222#endif