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 <linux/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
smbus_xfer(struct i2c_adapter * i2c_adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)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 -EOPNOTSUPP;
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 (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO;
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
bit_func(struct i2c_adapter * adap)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 */
i2c_sibyte_add_bus(struct i2c_adapter * i2c_adap,int speed)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_numbered_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 .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
i2c_sibyte_init(void)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
i2c_sibyte_exit(void)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");
199