114634da6c6e9f3a7bd7ca77bf04476fc1c2818c
[linux-2.6.git] / 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
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
40 static 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
118 static 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
127 static 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  */
135 static 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_adapter(i2c_adap);
147 }
148
149
150 static 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
155 static struct i2c_adapter sibyte_board_adapter[2] = {
156         {
157                 .owner          = THIS_MODULE,
158                 .id             = I2C_HW_SIBYTE,
159                 .class          = I2C_CLASS_HWMON,
160                 .algo           = NULL,
161                 .algo_data      = &sibyte_board_data[0],
162                 .name           = "SiByte SMBus 0",
163         },
164         {
165                 .owner          = THIS_MODULE,
166                 .id             = I2C_HW_SIBYTE,
167                 .class          = I2C_CLASS_HWMON,
168                 .algo           = NULL,
169                 .algo_data      = &sibyte_board_data[1],
170                 .name           = "SiByte SMBus 1",
171         },
172 };
173
174 static 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
187 static 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
193 module_init(i2c_sibyte_init);
194 module_exit(i2c_sibyte_exit);
195
196 MODULE_AUTHOR("Kip Walker (Broadcom Corp.), Steven J. Hill <sjhill@realitydiluted.com>");
197 MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");
198 MODULE_LICENSE("GPL");