LXR linux/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
  26struct 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
  36static 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
 114static 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
 123static 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 */
 131static 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
 146static 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
 151static 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
 170static 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
 183static 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
 189module_init(i2c_sibyte_init);
 190module_exit(i2c_sibyte_exit);
 191
 192MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
 193MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
 194MODULE_LICENSE("GPL");
 195