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32#include <linux/module.h>
33#include <linux/kernel.h>
34#include <linux/slab.h>
35#include <linux/init.h>
36#include <linux/i2c.h>
37#include <linux/mutex.h>
38
39extern struct i2c_adapter amd756_smbus;
40
41static struct i2c_adapter *s4882_adapter;
42static struct i2c_algorithm *s4882_algo;
43
44
45static DEFINE_MUTEX(amd756_lock);
46
47static s32 amd756_access_virt0(struct i2c_adapter * adap, u16 addr,
48 unsigned short flags, char read_write,
49 u8 command, int size,
50 union i2c_smbus_data * data)
51{
52 int error;
53
54
55 if (addr == 0x4c || (addr & 0xfc) == 0x50 || (addr & 0xfc) == 0x30
56 || addr == 0x18)
57 return -ENXIO;
58
59 mutex_lock(&amd756_lock);
60
61 error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
62 command, size, data);
63
64 mutex_unlock(&amd756_lock);
65
66 return error;
67}
68
69
70
71
72
73static u8 last_channels;
74
75static inline s32 amd756_access_channel(struct i2c_adapter * adap, u16 addr,
76 unsigned short flags, char read_write,
77 u8 command, int size,
78 union i2c_smbus_data * data,
79 u8 channels)
80{
81 int error;
82
83
84 if (addr != 0x4c && (addr & 0xfc) != 0x50 && (addr & 0xfc) != 0x30)
85 return -ENXIO;
86
87 mutex_lock(&amd756_lock);
88
89 if (last_channels != channels) {
90 union i2c_smbus_data mplxdata;
91 mplxdata.byte = channels;
92
93 error = amd756_smbus.algo->smbus_xfer(adap, 0x18, 0,
94 I2C_SMBUS_WRITE, 0x01,
95 I2C_SMBUS_BYTE_DATA,
96 &mplxdata);
97 if (error)
98 goto UNLOCK;
99 last_channels = channels;
100 }
101 error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
102 command, size, data);
103
104UNLOCK:
105 mutex_unlock(&amd756_lock);
106 return error;
107}
108
109static s32 amd756_access_virt1(struct i2c_adapter * adap, u16 addr,
110 unsigned short flags, char read_write,
111 u8 command, int size,
112 union i2c_smbus_data * data)
113{
114
115 return amd756_access_channel(adap, addr, flags, read_write, command,
116 size, data, 0x03);
117}
118
119static s32 amd756_access_virt2(struct i2c_adapter * adap, u16 addr,
120 unsigned short flags, char read_write,
121 u8 command, int size,
122 union i2c_smbus_data * data)
123{
124
125 return amd756_access_channel(adap, addr, flags, read_write, command,
126 size, data, 0x24);
127}
128
129static s32 amd756_access_virt3(struct i2c_adapter * adap, u16 addr,
130 unsigned short flags, char read_write,
131 u8 command, int size,
132 union i2c_smbus_data * data)
133{
134
135 return amd756_access_channel(adap, addr, flags, read_write, command,
136 size, data, 0x48);
137}
138
139static s32 amd756_access_virt4(struct i2c_adapter * adap, u16 addr,
140 unsigned short flags, char read_write,
141 u8 command, int size,
142 union i2c_smbus_data * data)
143{
144
145 return amd756_access_channel(adap, addr, flags, read_write, command,
146 size, data, 0x90);
147}
148
149static int __init amd756_s4882_init(void)
150{
151 int i, error;
152 union i2c_smbus_data ioconfig;
153
154 if (!amd756_smbus.dev.parent)
155 return -ENODEV;
156
157
158 ioconfig.byte = 0x00;
159 error = i2c_smbus_xfer(&amd756_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
160 I2C_SMBUS_BYTE_DATA, &ioconfig);
161 if (error) {
162 dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
163 error = -EIO;
164 goto ERROR0;
165 }
166
167
168 i2c_del_adapter(&amd756_smbus);
169
170 printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4882\n");
171
172 if (!(s4882_adapter = kzalloc(5 * sizeof(struct i2c_adapter),
173 GFP_KERNEL))) {
174 error = -ENOMEM;
175 goto ERROR1;
176 }
177 if (!(s4882_algo = kzalloc(5 * sizeof(struct i2c_algorithm),
178 GFP_KERNEL))) {
179 error = -ENOMEM;
180 goto ERROR2;
181 }
182
183
184 s4882_algo[0] = *(amd756_smbus.algo);
185 s4882_algo[0].smbus_xfer = amd756_access_virt0;
186 s4882_adapter[0] = amd756_smbus;
187 s4882_adapter[0].algo = s4882_algo;
188 s4882_adapter[0].dev.parent = amd756_smbus.dev.parent;
189 for (i = 1; i < 5; i++) {
190 s4882_algo[i] = *(amd756_smbus.algo);
191 s4882_adapter[i] = amd756_smbus;
192 snprintf(s4882_adapter[i].name, sizeof(s4882_adapter[i].name),
193 "SMBus 8111 adapter (CPU%d)", i-1);
194 s4882_adapter[i].algo = s4882_algo+i;
195 s4882_adapter[i].dev.parent = amd756_smbus.dev.parent;
196 }
197 s4882_algo[1].smbus_xfer = amd756_access_virt1;
198 s4882_algo[2].smbus_xfer = amd756_access_virt2;
199 s4882_algo[3].smbus_xfer = amd756_access_virt3;
200 s4882_algo[4].smbus_xfer = amd756_access_virt4;
201
202
203 for (i = 0; i < 5; i++) {
204 error = i2c_add_adapter(s4882_adapter+i);
205 if (error) {
206 printk(KERN_ERR "i2c-amd756-s4882: "
207 "Virtual adapter %d registration "
208 "failed, module not inserted\n", i);
209 for (i--; i >= 0; i--)
210 i2c_del_adapter(s4882_adapter+i);
211 goto ERROR3;
212 }
213 }
214
215 return 0;
216
217ERROR3:
218 kfree(s4882_algo);
219 s4882_algo = NULL;
220ERROR2:
221 kfree(s4882_adapter);
222 s4882_adapter = NULL;
223ERROR1:
224
225 i2c_add_adapter(&amd756_smbus);
226ERROR0:
227 return error;
228}
229
230static void __exit amd756_s4882_exit(void)
231{
232 if (s4882_adapter) {
233 int i;
234
235 for (i = 0; i < 5; i++)
236 i2c_del_adapter(s4882_adapter+i);
237 kfree(s4882_adapter);
238 s4882_adapter = NULL;
239 }
240 kfree(s4882_algo);
241 s4882_algo = NULL;
242
243
244 if (i2c_add_adapter(&amd756_smbus))
245 printk(KERN_ERR "i2c-amd756-s4882: "
246 "Physical bus restoration failed\n");
247}
248
249MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
250MODULE_DESCRIPTION("S4882 SMBus multiplexing");
251MODULE_LICENSE("GPL");
252
253module_init(amd756_s4882_init);
254module_exit(amd756_s4882_exit);
255