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 * 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
  30struct 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
  40static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
  41                      unsigned short flags, char read_write,
  42                      u8 command, int size, union i2c_smbus_data * data)
  43{
  44        struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
  45        int data_bytes = 0;
  46        int error;
  47
  48        while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
  49                ;
  50
  51        switch (size) {
  52        case I2C_SMBUS_QUICK:
  53                csr_out32((V_SMB_ADDR(addr) |
  54                           (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
  55                           V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
  56                break;
  57        case I2C_SMBUS_BYTE:
  58                if (read_write == I2C_SMBUS_READ) {
  59                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
  60                                  SMB_CSR(adap, R_SMB_START));
  61                        data_bytes = 1;
  62                } else {
  63                        csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
  64                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
  65                                  SMB_CSR(adap, R_SMB_START));
  66                }
  67                break;
  68        case I2C_SMBUS_BYTE_DATA:
  69                csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
  70                if (read_write == I2C_SMBUS_READ) {
  71                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
  72                                  SMB_CSR(adap, R_SMB_START));
  73                        data_bytes = 1;
  74                } else {
  75                        csr_out32(V_SMB_LB(data->byte),
  76                                  SMB_CSR(adap, R_SMB_DATA));
  77                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
  78                                  SMB_CSR(adap, R_SMB_START));
  79                }
  80                break;
  81        case I2C_SMBUS_WORD_DATA:
  82                csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
  83                if (read_write == I2C_SMBUS_READ) {
  84                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
  85                                  SMB_CSR(adap, R_SMB_START));
  86                        data_bytes = 2;
  87                } else {
  88                        csr_out32(V_SMB_LB(data->word & 0xff),
  89                                  SMB_CSR(adap, R_SMB_DATA));
  90                        csr_out32(V_SMB_MB(data->word >> 8),
  91                                  SMB_CSR(adap, R_SMB_DATA));
  92                        csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
  93                                  SMB_CSR(adap, R_SMB_START));
  94                }
  95                break;
  96        default:
  97                return -1;      /* XXXKW better error code? */
  98        }
  99
 100        while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
 101                ;
 102
 103        error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
 104        if (error & M_SMB_ERROR) {
 105                /* Clear error bit by writing a 1 */
 106                csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
 107                return -1;      /* XXXKW better error code? */
 108        }
 109
 110        if (data_bytes == 1)
 111                data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
 112        if (data_bytes == 2)
 113                data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
 114
 115        return 0;
 116}
 117
 118static u32 bit_func(struct i2c_adapter *adap)
 119{
 120        return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 121                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
 122}
 123
 124
 125/* -----exported algorithm data: -------------------------------------  */
 126
 127static const struct i2c_algorithm i2c_sibyte_algo = {
 128        .smbus_xfer     = smbus_xfer,
 129        .functionality  = bit_func,
 130};
 131
 132/*
 133 * registering functions to load algorithms at runtime
 134 */
 135static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
 136{
 137        struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
 138
 139        /* Register new adapter to i2c module... */
 140        i2c_adap->algo = &i2c_sibyte_algo;
 141
 142        /* Set the requested frequency. */
 143        csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
 144        csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
 145
 146        return i2c_add_numbered_adapter(i2c_adap);
 147}
 148
 149
 150static struct i2c_algo_sibyte_data sibyte_board_data[2] = {
 151        { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) },
 152        { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) }
 153};
 154
 155static struct i2c_adapter sibyte_board_adapter[2] = {
 156        {
 157                .owner          = THIS_MODULE,
 158                .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 159                .algo           = NULL,
 160                .algo_data      = &sibyte_board_data[0],
 161                .nr             = 0,
 162                .name           = "SiByte SMBus 0",
 163        },
 164        {
 165                .owner          = THIS_MODULE,
 166                .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 167                .algo           = NULL,
 168                .algo_data      = &sibyte_board_data[1],
 169                .nr             = 1,
 170                .name           = "SiByte SMBus 1",
 171        },
 172};
 173
 174static int __init i2c_sibyte_init(void)
 175{
 176        pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n");
 177        if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0)
 178                return -ENODEV;
 179        if (i2c_sibyte_add_bus(&sibyte_board_adapter[1],
 180                               K_SMB_FREQ_400KHZ) < 0) {
 181                i2c_del_adapter(&sibyte_board_adapter[0]);
 182                return -ENODEV;
 183        }
 184        return 0;
 185}
 186
 187static void __exit i2c_sibyte_exit(void)
 188{
 189        i2c_del_adapter(&sibyte_board_adapter[0]);
 190        i2c_del_adapter(&sibyte_board_adapter[1]);
 191}
 192
 193module_init(i2c_sibyte_init);
 194module_exit(i2c_sibyte_exit);
 195
 196MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
 197MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
 198MODULE_LICENSE("GPL");
 199