1 /* 2 * Copyright (C) 2004 Steven J. Hill 3 * Copyright (C) 2001,2002,2003 Broadcom Corporation 4 * Copyright (C) 1995-2000 Simon G. Vogl 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 2 9 * of the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/i2c.h> 25 #include <asm/io.h> 26 #include <asm/sibyte/sb1250_regs.h> 27 #include <asm/sibyte/sb1250_smbus.h> 28 29 30 struct i2c_algo_sibyte_data { 31 void *data; /* private data */ 32 int bus; /* which bus */ 33 void *reg_base; /* CSR base */ 34 }; 35 36 /* ----- global defines ----------------------------------------------- */ 37 #define SMB_CSR(a,r) ((long)(a->reg_base + r)) 38 39 /* ----- global variables --------------------------------------------- */ 40 41 /* module parameters: 42 */ 43 static int bit_scan; /* have a look at what's hanging 'round */ 44 module_param(bit_scan, int, 0); 45 MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus"); 46 47 48 static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, 49 unsigned short flags, char read_write, 50 u8 command, int size, union i2c_smbus_data * data) 51 { 52 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 53 int data_bytes = 0; 54 int error; 55 56 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 57 ; 58 59 switch (size) { 60 case I2C_SMBUS_QUICK: 61 csr_out32((V_SMB_ADDR(addr) | 62 (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), 84 SMB_CSR(adap, R_SMB_DATA)); 85 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 86 SMB_CSR(adap, R_SMB_START)); 87 } 88 break; 89 case I2C_SMBUS_WORD_DATA: 90 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 91 if (read_write == I2C_SMBUS_READ) { 92 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE), 93 SMB_CSR(adap, R_SMB_START)); 94 data_bytes = 2; 95 } else { 96 csr_out32(V_SMB_LB(data->word & 0xff), 97 SMB_CSR(adap, R_SMB_DATA)); 98 csr_out32(V_SMB_MB(data->word >> 8), 99 SMB_CSR(adap, R_SMB_DATA)); 100 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 101 SMB_CSR(adap, R_SMB_START)); 102 } 103 break; 104 default: 105 return -1; /* XXXKW better error code? */ 106 } 107 108 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 109 ; 110 111 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS)); 112 if (error & M_SMB_ERROR) { 113 /* Clear error bit by writing a 1 */ 114 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS)); 115 return -1; /* XXXKW better error code? */ 116 } 117 118 if (data_bytes == 1) 119 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff; 120 if (data_bytes == 2) 121 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff; 122 123 return 0; 124 } 125 126 static u32 bit_func(struct i2c_adapter *adap) 127 { 128 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 129 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA); 130 } 131 132 133 /* -----exported algorithm data: ------------------------------------- */ 134 135 static const struct i2c_algorithm i2c_sibyte_algo = { 136 .smbus_xfer = smbus_xfer, 137 .functionality = bit_func, 138 }; 139 140 /* 141 * registering functions to load algorithms at runtime 142 */ 143 int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed) 144 { 145 int i; 146 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 147 148 /* register new adapter to i2c module... */ 149 i2c_adap->algo = &i2c_sibyte_algo; 150 151 /* Set the frequency to 100 kHz */ 152 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ)); 153 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL)); 154 155 /* scan bus */ 156 if (bit_scan) { 157 union i2c_smbus_data data; 158 int rc; 159 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n", 160 i2c_adap->name); 161 for (i = 0x00; i < 0x7f; i++) { 162 /* XXXKW is this a realistic probe? */ 163 rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0, 164 I2C_SMBUS_BYTE_DATA, &data); 165 if (!rc) { 166 printk("(%02x)",i); 167 } else 168 printk("."); 169 } 170 printk("\n"); 171 } 172 173 return i2c_add_adapter(i2c_adap); 174 } 175 176 177 static struct i2c_algo_sibyte_data sibyte_board_data[2] = { 178 { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) }, 179 { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) } 180 }; 181 182 static struct i2c_adapter sibyte_board_adapter[2] = { 183 { 184 .owner = THIS_MODULE, 185 .id = I2C_HW_SIBYTE, 186 .class = I2C_CLASS_HWMON, 187 .algo = NULL, 188 .algo_data = &sibyte_board_data[0], 189 .name = "SiByte SMBus 0", 190 }, 191 { 192 .owner = THIS_MODULE, 193 .id = I2C_HW_SIBYTE, 194 .class = I2C_CLASS_HWMON, 195 .algo = NULL, 196 .algo_data = &sibyte_board_data[1], 197 .name = "SiByte SMBus 1", 198 }, 199 }; 200 201 static int __init i2c_sibyte_init(void) 202 { 203 printk("i2c-swarm.o: i2c SMBus adapter module for SiByte board\n"); 204 if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0) 205 return -ENODEV; 206 if (i2c_sibyte_add_bus(&sibyte_board_adapter[1], K_SMB_FREQ_400KHZ) < 0) 207 return -ENODEV; 208 return 0; 209 } 210 211 static void __exit i2c_sibyte_exit(void) 212 { 213 i2c_del_adapter(&sibyte_board_adapter[0]); 214 i2c_del_adapter(&sibyte_board_adapter[1]); 215 } 216 217 module_init(i2c_sibyte_init); 218 module_exit(i2c_sibyte_exit); 219 220 MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>"); 221 MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards"); 222 MODULE_LICENSE("GPL"); 223