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 Ky�sti M�lkki <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/config.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31
32 #include <asm/sibyte/64bit.h>
33 #include <asm/sibyte/sb1250_regs.h>
34 #include <asm/sibyte/sb1250_smbus.h>
35
36 #include <linux/i2c.h>
37 #include <linux/i2c-algo-sibyte.h>
38
39 /* ----- global defines ----------------------------------------------- */
40 #define SMB_CSR(a,r) ((long)(a->reg_base + r))
41
42 /* ----- global variables --------------------------------------------- */
43
44 /* module parameters:
45 */
46 static int bit_scan=0; /* have a look at what's hanging 'round */
47
48
smbus_xfer(struct i2c_adapter * i2c_adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)49 static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,
50 unsigned short flags, char read_write,
51 u8 command, int size, union i2c_smbus_data * data)
52 {
53 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
54 int data_bytes = 0;
55 int error;
56
57 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
58 ;
59
60 switch (size) {
61 case I2C_SMBUS_QUICK:
62 csr_out32((V_SMB_ADDR(addr) | (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |
63 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));
64 break;
65 case I2C_SMBUS_BYTE:
66 if (read_write == I2C_SMBUS_READ) {
67 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),
68 SMB_CSR(adap, R_SMB_START));
69 data_bytes = 1;
70 } else {
71 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
72 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),
73 SMB_CSR(adap, R_SMB_START));
74 }
75 break;
76 case I2C_SMBUS_BYTE_DATA:
77 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
78 if (read_write == I2C_SMBUS_READ) {
79 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),
80 SMB_CSR(adap, R_SMB_START));
81 data_bytes = 1;
82 } else {
83 csr_out32(V_SMB_LB(data->byte), SMB_CSR(adap, R_SMB_DATA));
84 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
85 SMB_CSR(adap, R_SMB_START));
86 }
87 break;
88 case I2C_SMBUS_WORD_DATA:
89 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));
90 if (read_write == I2C_SMBUS_READ) {
91 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),
92 SMB_CSR(adap, R_SMB_START));
93 data_bytes = 2;
94 } else {
95 csr_out32(V_SMB_LB(data->word & 0xff), SMB_CSR(adap, R_SMB_DATA));
96 csr_out32(V_SMB_MB(data->word >> 8), SMB_CSR(adap, R_SMB_DATA));
97 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),
98 SMB_CSR(adap, R_SMB_START));
99 }
100 break;
101 default:
102 return -1; /* XXXKW better error code? */
103 }
104
105 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)
106 ;
107
108 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));
109 if (error & M_SMB_ERROR) {
110 /* Clear error bit by writing a 1 */
111 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));
112 return -1; /* XXXKW better error code? */
113 }
114
115 if (data_bytes == 1)
116 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;
117 if (data_bytes == 2)
118 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;
119
120 return 0;
121 }
122
algo_control(struct i2c_adapter * adapter,unsigned int cmd,unsigned long arg)123 static int algo_control(struct i2c_adapter *adapter,
124 unsigned int cmd, unsigned long arg)
125 {
126 return 0;
127 }
128
bit_func(struct i2c_adapter * adap)129 static u32 bit_func(struct i2c_adapter *adap)
130 {
131 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
132 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);
133 }
134
135
136 /* -----exported algorithm data: ------------------------------------- */
137
138 static struct i2c_algorithm i2c_sibyte_algo = {
139 "SiByte algorithm",
140 I2C_ALGO_SIBYTE,
141 NULL, /* master_xfer */
142 smbus_xfer, /* smbus_xfer */
143 NULL, /* slave_xmit */
144 NULL, /* slave_recv */
145 algo_control, /* ioctl */
146 bit_func, /* functionality */
147 };
148
149 /*
150 * registering functions to load algorithms at runtime
151 */
i2c_sibyte_add_bus(struct i2c_adapter * i2c_adap,int speed)152 int i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
153 {
154 int i;
155 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;
156
157 /* register new adapter to i2c module... */
158
159 i2c_adap->id |= i2c_sibyte_algo.id;
160 i2c_adap->algo = &i2c_sibyte_algo;
161
162 /* Set the frequency to 100 kHz */
163 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));
164 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));
165
166 /* scan bus */
167 if (bit_scan) {
168 union i2c_smbus_data data;
169 int rc;
170 printk(KERN_INFO " i2c-algo-sibyte.o: scanning bus %s.\n",
171 i2c_adap->name);
172 for (i = 0x00; i < 0x7f; i++) {
173 /* XXXKW is this a realistic probe? */
174 rc = smbus_xfer(i2c_adap, i, 0, I2C_SMBUS_READ, 0,
175 I2C_SMBUS_BYTE_DATA, &data);
176 if (!rc) {
177 printk("(%02x)",i);
178 } else
179 printk(".");
180 }
181 printk("\n");
182 }
183
184 #ifdef MODULE
185 MOD_INC_USE_COUNT;
186 #endif
187
188 return i2c_add_adapter(i2c_adap);
189 }
190
191
i2c_sibyte_del_bus(struct i2c_adapter * adap)192 int i2c_sibyte_del_bus(struct i2c_adapter *adap)
193 {
194 int res;
195
196 if ((res = i2c_del_adapter(adap)) < 0)
197 return res;
198
199 #ifdef MODULE
200 MOD_DEC_USE_COUNT;
201 #endif
202 return 0;
203 }
204
i2c_algo_sibyte_init(void)205 int __init i2c_algo_sibyte_init (void)
206 {
207 printk("i2c-algo-sibyte.o: i2c SiByte algorithm module\n");
208 return 0;
209 }
210
211
212 EXPORT_SYMBOL(i2c_sibyte_add_bus);
213 EXPORT_SYMBOL(i2c_sibyte_del_bus);
214
215 #ifdef MODULE
216 MODULE_AUTHOR("Kip Walker, Broadcom Corp.");
217 MODULE_DESCRIPTION("SiByte I2C-Bus algorithm");
218 MODULE_PARM(bit_scan, "i");
219 MODULE_PARM_DESC(bit_scan, "Scan for active chips on the bus");
220 MODULE_LICENSE("GPL");
221
init_module(void)222 int init_module(void)
223 {
224 return i2c_algo_sibyte_init();
225 }
226
cleanup_module(void)227 void cleanup_module(void)
228 {
229 }
230 #endif
231