drivers/i2c/busses/i2c-sibyte.c

   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");