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30#include <linux/module.h>
31#include <linux/kernel.h>
32#include <linux/slab.h>
33#include <linux/init.h>
34#include <linux/i2c.h>
35#include <linux/mutex.h>
36
37extern struct i2c_adapter *nforce2_smbus;
38
39static struct i2c_adapter *s4985_adapter;
40static struct i2c_algorithm *s4985_algo;
41
42
43static DEFINE_MUTEX(nforce2_lock);
44
45static s32 nforce2_access_virt0(struct i2c_adapter *adap, u16 addr,
46 unsigned short flags, char read_write,
47 u8 command, int size,
48 union i2c_smbus_data *data)
49{
50 int error;
51
52
53 if ((addr & 0xfc) == 0x50 || (addr & 0xfc) == 0x30
54 || addr == 0x18)
55 return -ENXIO;
56
57 mutex_lock(&nforce2_lock);
58 error = nforce2_smbus->algo->smbus_xfer(adap, addr, flags, read_write,
59 command, size, data);
60 mutex_unlock(&nforce2_lock);
61
62 return error;
63}
64
65
66
67
68
69static u8 last_channels;
70
71static inline s32 nforce2_access_channel(struct i2c_adapter *adap, u16 addr,
72 unsigned short flags, char read_write,
73 u8 command, int size,
74 union i2c_smbus_data *data,
75 u8 channels)
76{
77 int error;
78
79
80 if ((addr & 0xfc) != 0x50 && (addr & 0xfc) != 0x30)
81 return -ENXIO;
82
83 mutex_lock(&nforce2_lock);
84 if (last_channels != channels) {
85 union i2c_smbus_data mplxdata;
86 mplxdata.byte = channels;
87
88 error = nforce2_smbus->algo->smbus_xfer(adap, 0x18, 0,
89 I2C_SMBUS_WRITE, 0x01,
90 I2C_SMBUS_BYTE_DATA,
91 &mplxdata);
92 if (error)
93 goto UNLOCK;
94 last_channels = channels;
95 }
96 error = nforce2_smbus->algo->smbus_xfer(adap, addr, flags, read_write,
97 command, size, data);
98
99UNLOCK:
100 mutex_unlock(&nforce2_lock);
101 return error;
102}
103
104static s32 nforce2_access_virt1(struct i2c_adapter *adap, u16 addr,
105 unsigned short flags, char read_write,
106 u8 command, int size,
107 union i2c_smbus_data *data)
108{
109
110 return nforce2_access_channel(adap, addr, flags, read_write, command,
111 size, data, 0x02);
112}
113
114static s32 nforce2_access_virt2(struct i2c_adapter *adap, u16 addr,
115 unsigned short flags, char read_write,
116 u8 command, int size,
117 union i2c_smbus_data *data)
118{
119
120 return nforce2_access_channel(adap, addr, flags, read_write, command,
121 size, data, 0x04);
122}
123
124static s32 nforce2_access_virt3(struct i2c_adapter *adap, u16 addr,
125 unsigned short flags, char read_write,
126 u8 command, int size,
127 union i2c_smbus_data *data)
128{
129
130 return nforce2_access_channel(adap, addr, flags, read_write, command,
131 size, data, 0x08);
132}
133
134static s32 nforce2_access_virt4(struct i2c_adapter *adap, u16 addr,
135 unsigned short flags, char read_write,
136 u8 command, int size,
137 union i2c_smbus_data *data)
138{
139
140 return nforce2_access_channel(adap, addr, flags, read_write, command,
141 size, data, 0x10);
142}
143
144static int __init nforce2_s4985_init(void)
145{
146 int i, error;
147 union i2c_smbus_data ioconfig;
148
149 if (!nforce2_smbus)
150 return -ENODEV;
151
152
153 ioconfig.byte = 0x00;
154 error = i2c_smbus_xfer(nforce2_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
155 I2C_SMBUS_BYTE_DATA, &ioconfig);
156 if (error) {
157 dev_err(&nforce2_smbus->dev, "PCA9556 configuration failed\n");
158 error = -EIO;
159 goto ERROR0;
160 }
161
162
163 i2c_del_adapter(nforce2_smbus);
164
165 printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4985\n");
166
167 s4985_adapter = kzalloc(5 * sizeof(struct i2c_adapter), GFP_KERNEL);
168 if (!s4985_adapter) {
169 error = -ENOMEM;
170 goto ERROR1;
171 }
172 s4985_algo = kzalloc(5 * sizeof(struct i2c_algorithm), GFP_KERNEL);
173 if (!s4985_algo) {
174 error = -ENOMEM;
175 goto ERROR2;
176 }
177
178
179 s4985_algo[0] = *(nforce2_smbus->algo);
180 s4985_algo[0].smbus_xfer = nforce2_access_virt0;
181 s4985_adapter[0] = *nforce2_smbus;
182 s4985_adapter[0].algo = s4985_algo;
183 s4985_adapter[0].dev.parent = nforce2_smbus->dev.parent;
184 for (i = 1; i < 5; i++) {
185 s4985_algo[i] = *(nforce2_smbus->algo);
186 s4985_adapter[i] = *nforce2_smbus;
187 snprintf(s4985_adapter[i].name, sizeof(s4985_adapter[i].name),
188 "SMBus nForce2 adapter (CPU%d)", i - 1);
189 s4985_adapter[i].algo = s4985_algo + i;
190 s4985_adapter[i].dev.parent = nforce2_smbus->dev.parent;
191 }
192 s4985_algo[1].smbus_xfer = nforce2_access_virt1;
193 s4985_algo[2].smbus_xfer = nforce2_access_virt2;
194 s4985_algo[3].smbus_xfer = nforce2_access_virt3;
195 s4985_algo[4].smbus_xfer = nforce2_access_virt4;
196
197
198 for (i = 0; i < 5; i++) {
199 error = i2c_add_adapter(s4985_adapter + i);
200 if (error) {
201 printk(KERN_ERR "i2c-nforce2-s4985: "
202 "Virtual adapter %d registration "
203 "failed, module not inserted\n", i);
204 for (i--; i >= 0; i--)
205 i2c_del_adapter(s4985_adapter + i);
206 goto ERROR3;
207 }
208 }
209
210 return 0;
211
212ERROR3:
213 kfree(s4985_algo);
214 s4985_algo = NULL;
215ERROR2:
216 kfree(s4985_adapter);
217 s4985_adapter = NULL;
218ERROR1:
219
220 i2c_add_adapter(nforce2_smbus);
221ERROR0:
222 return error;
223}
224
225static void __exit nforce2_s4985_exit(void)
226{
227 if (s4985_adapter) {
228 int i;
229
230 for (i = 0; i < 5; i++)
231 i2c_del_adapter(s4985_adapter+i);
232 kfree(s4985_adapter);
233 s4985_adapter = NULL;
234 }
235 kfree(s4985_algo);
236 s4985_algo = NULL;
237
238
239 if (i2c_add_adapter(nforce2_smbus))
240 printk(KERN_ERR "i2c-nforce2-s4985: "
241 "Physical bus restoration failed\n");
242}
243
244MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
245MODULE_DESCRIPTION("S4985 SMBus multiplexing");
246MODULE_LICENSE("GPL");
247
248module_init(nforce2_s4985_init);
249module_exit(nforce2_s4985_exit);
250