Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/i2c-2.6
[linux-2.6] / drivers / i2c / algos / i2c-algo-sibyte.c
1 /* ------------------------------------------------------------------------- */
2 /* i2c-algo-sibyte.c i2c driver algorithms for bit-shift adapters                    */
3 /* ------------------------------------------------------------------------- */
4 /*   Copyright (C) 2001,2002,2003 Broadcom Corporation
5      Copyright (C) 1995-2000 Simon G. Vogl
6
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
20 /* ------------------------------------------------------------------------- */
21
22 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
23    Frodo Looijaard <frodol@dds.nl>.  */
24
25 /* Ported for SiByte SOCs by Broadcom Corporation.  */
26
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/init.h>
30
31 #include <asm/io.h>
32 #include <asm/sibyte/sb1250_regs.h>
33 #include <asm/sibyte/sb1250_smbus.h>
34
35 #include <linux/i2c.h>
36 #include <linux/i2c-algo-sibyte.h>
37
38 /* ----- global defines ----------------------------------------------- */
39 #define SMB_CSR(a,r) ((long)(a->reg_base + r))
40
41 /* ----- global variables --------------------------------------------- */
42
43 /* module parameters:
44  */
45 static int bit_scan;    /* have a look at what's hanging 'round         */
46
47
48 static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr, 
49                       unsigned short flags, char read_write,
50                       u8 command, int size, union i2c_smbus_data * data)
51 {
52         struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
53         int data_bytes = 0;
54         int error;
55
56         while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
57                 ;
58
59         switch (size) {
60         case I2C_SMBUS_QUICK:
61                 csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
62                            V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
63                 break;
64         case I2C_SMBUS_BYTE:
65                 if (read_write == I2C_SMBUS_READ) {
66                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
67                                   SMB_CSR(adap, R_SMB_START));
68                         data_bytes = 1;
69                 } else {
70                         csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
71                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
72                                   SMB_CSR(adap, R_SMB_START));
73                 }
74                 break;
75         case I2C_SMBUS_BYTE_DATA:
76                 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
77                 if (read_write == I2C_SMBUS_READ) {
78                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
79                                   SMB_CSR(adap, R_SMB_START));
80                         data_bytes = 1;
81                 } else {
82                         csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
83                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
84                                   SMB_CSR(adap, R_SMB_START));
85                 }
86                 break;
87         case I2C_SMBUS_WORD_DATA:
88                 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
89                 if (read_write == I2C_SMBUS_READ) {
90                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
91                                   SMB_CSR(adap, R_SMB_START));
92                         data_bytes = 2;
93                 } else {
94                         csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
95                         csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
96                         csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
97                                   SMB_CSR(adap, R_SMB_START));
98                 }
99                 break;
100         default:
101                 return -1;      /* XXXKW better error code? */
102         }
103
104         while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
105                 ;
106
107         error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
108         if (error & M_SMB_ERROR) {
109                 /* Clear error bit by writing a 1 */
110                 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
111                 return -1;      /* XXXKW better error code? */
112         }
113
114         if (data_bytes == 1)
115                 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
116         if (data_bytes == 2)
117                 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
118
119         return 0;
120 }
121
122 static int algo_control(struct i2c_adapter *adapter, 
123         unsigned int cmd, unsigned long arg)
124 {
125         return 0;
126 }
127
128 static u32 bit_func(struct i2c_adapter *adap)
129 {
130         return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
131                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
132 }
133
134
135 /* -----exported algorithm data: -------------------------------------  */
136
137 static struct i2c_algorithm i2c_sibyte_algo = {
138         .smbus_xfer     = smbus_xfer,
139         .algo_control   = algo_control, /* ioctl */
140         .functionality  = bit_func,
141 };
142
143 /* 
144  * registering functions to load algorithms at runtime 
145  */
146 int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
147 {
148         int i;
149         struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
150
151         /* register new adapter to i2c module... */
152         i2c_adap->algo = &i2c_sibyte_algo;
153         
154         /* Set the frequency to 100 kHz */
155         csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
156         csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
157
158         /* scan bus */
159         if (bit_scan) {
160                 union i2c_smbus_data data;
161                 int rc;
162                 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
163                        i2c_adap->name);
164                 for (i = 0x00; i < 0x7f; i++) {
165                         /* XXXKW is this a realistic probe? */
166                         rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
167                                         I2C_SMBUS_BYTE_DATA, &data);
168                         if (!rc) {
169                                 printk("(%02x)",i); 
170                         } else 
171                                 printk("."); 
172                 }
173                 printk("\n");
174         }
175
176         i2c_add_adapter(i2c_adap);
177
178         return 0;
179 }
180
181
182 int i2c_sibyte_del_bus(struct i2c_adapter *adap)
183 {
184         int res;
185
186         if ((res = i2c_del_adapter(adap)) < 0)
187                 return res;
188
189         return 0;
190 }
191
192 int __init i2c_algo_sibyte_init (void)
193 {
194         printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n");
195         return 0;
196 }
197
198
199 EXPORT_SYMBOL(i2c_sibyte_add_bus);
200 EXPORT_SYMBOL(i2c_sibyte_del_bus);
201
202 #ifdef MODULE
203 MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
204 MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
205 MODULE_PARM(bit_scan, "i");
206 MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
207 MODULE_LICENSE("GPL");
208
209 int init_module(void) 
210 {
211         return i2c_algo_sibyte_init();
212 }
213
214 void cleanup_module(void) 
215 {
216 }
217 #endif