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 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/i2c.h> 21 #include <linux/io.h> 22 #include <asm/sibyte/sb1250_regs.h> 23 #include <asm/sibyte/sb1250_smbus.h> 24 25 26 struct i2c_algo_sibyte_data { 27 void *data; /* private data */ 28 int bus; /* which bus */ 29 void *reg_base; /* CSR base */ 30 }; 31 32 /* ----- global defines ----------------------------------------------- */ 33 #define SMB_CSR(a,r) ((long)(a->reg_base + r)) 34 35 36 static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, 37 unsigned short flags, char read_write, 38 u8 command, int size, union i2c_smbus_data * data) 39 { 40 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 41 int data_bytes = 0; 42 int error; 43 44 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 45 ; 46 47 switch (size) { 48 case I2C_SMBUS_QUICK: 49 csr_out32((V_SMB_ADDR(addr) | 50 (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) | 51 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START)); 52 break; 53 case I2C_SMBUS_BYTE: 54 if (read_write == I2C_SMBUS_READ) { 55 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE), 56 SMB_CSR(adap, R_SMB_START)); 57 data_bytes = 1; 58 } else { 59 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 60 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE), 61 SMB_CSR(adap, R_SMB_START)); 62 } 63 break; 64 case I2C_SMBUS_BYTE_DATA: 65 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 66 if (read_write == I2C_SMBUS_READ) { 67 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE), 68 SMB_CSR(adap, R_SMB_START)); 69 data_bytes = 1; 70 } else { 71 csr_out32(V_SMB_LB(data->byte), 72 SMB_CSR(adap, R_SMB_DATA)); 73 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 74 SMB_CSR(adap, R_SMB_START)); 75 } 76 break; 77 case I2C_SMBUS_WORD_DATA: 78 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD)); 79 if (read_write == I2C_SMBUS_READ) { 80 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE), 81 SMB_CSR(adap, R_SMB_START)); 82 data_bytes = 2; 83 } else { 84 csr_out32(V_SMB_LB(data->word & 0xff), 85 SMB_CSR(adap, R_SMB_DATA)); 86 csr_out32(V_SMB_MB(data->word >> 8), 87 SMB_CSR(adap, R_SMB_DATA)); 88 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE), 89 SMB_CSR(adap, R_SMB_START)); 90 } 91 break; 92 default: 93 return -EOPNOTSUPP; 94 } 95 96 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY) 97 ; 98 99 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS)); 100 if (error & M_SMB_ERROR) { 101 /* Clear error bit by writing a 1 */ 102 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS)); 103 return (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO; 104 } 105 106 if (data_bytes == 1) 107 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff; 108 if (data_bytes == 2) 109 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff; 110 111 return 0; 112 } 113 114 static u32 bit_func(struct i2c_adapter *adap) 115 { 116 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 117 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA); 118 } 119 120 121 /* -----exported algorithm data: ------------------------------------- */ 122 123 static const struct i2c_algorithm i2c_sibyte_algo = { 124 .smbus_xfer = smbus_xfer, 125 .functionality = bit_func, 126 }; 127 128 /* 129 * registering functions to load algorithms at runtime 130 */ 131 static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed) 132 { 133 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data; 134 135 /* Register new adapter to i2c module... */ 136 i2c_adap->algo = &i2c_sibyte_algo; 137 138 /* Set the requested frequency. */ 139 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ)); 140 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL)); 141 142 return i2c_add_numbered_adapter(i2c_adap); 143 } 144 145 146 static struct i2c_algo_sibyte_data sibyte_board_data[2] = { 147 { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) }, 148 { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) } 149 }; 150 151 static struct i2c_adapter sibyte_board_adapter[2] = { 152 { 153 .owner = THIS_MODULE, 154 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 155 .algo = NULL, 156 .algo_data = &sibyte_board_data[0], 157 .nr = 0, 158 .name = "SiByte SMBus 0", 159 }, 160 { 161 .owner = THIS_MODULE, 162 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 163 .algo = NULL, 164 .algo_data = &sibyte_board_data[1], 165 .nr = 1, 166 .name = "SiByte SMBus 1", 167 }, 168 }; 169 170 static int __init i2c_sibyte_init(void) 171 { 172 pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n"); 173 if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0) 174 return -ENODEV; 175 if (i2c_sibyte_add_bus(&sibyte_board_adapter[1], 176 K_SMB_FREQ_400KHZ) < 0) { 177 i2c_del_adapter(&sibyte_board_adapter[0]); 178 return -ENODEV; 179 } 180 return 0; 181 } 182 183 static void __exit i2c_sibyte_exit(void) 184 { 185 i2c_del_adapter(&sibyte_board_adapter[0]); 186 i2c_del_adapter(&sibyte_board_adapter[1]); 187 } 188 189 module_init(i2c_sibyte_init); 190 module_exit(i2c_sibyte_exit); 191 192 MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>"); 193 MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards"); 194 MODULE_LICENSE("GPL"); 195