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28#include <linux/module.h>
29#include <linux/pci.h>
30#include <linux/kernel.h>
31#include <linux/delay.h>
32#include <linux/stddef.h>
33#include <linux/ioport.h>
34#include <linux/i2c.h>
35#include <linux/acpi.h>
36#include <linux/io.h>
37
38
39#define SIS96x_BAR 0x04
40
41
42#define SMB_STS 0x00
43#define SMB_EN 0x01
44#define SMB_CNT 0x02
45#define SMB_HOST_CNT 0x03
46#define SMB_ADDR 0x04
47#define SMB_CMD 0x05
48#define SMB_PCOUNT 0x06
49#define SMB_COUNT 0x07
50#define SMB_BYTE 0x08
51#define SMB_DEV_ADDR 0x10
52#define SMB_DB0 0x11
53#define SMB_DB1 0x12
54#define SMB_SAA 0x13
55
56
57#define SMB_IOSIZE 0x20
58
59
60#define MAX_TIMEOUT 500
61
62
63#define SIS96x_QUICK 0x00
64#define SIS96x_BYTE 0x01
65#define SIS96x_BYTE_DATA 0x02
66#define SIS96x_WORD_DATA 0x03
67#define SIS96x_PROC_CALL 0x04
68#define SIS96x_BLOCK_DATA 0x05
69
70static struct pci_driver sis96x_driver;
71static struct i2c_adapter sis96x_adapter;
72static u16 sis96x_smbus_base;
73
74static inline u8 sis96x_read(u8 reg)
75{
76 return inb(sis96x_smbus_base + reg) ;
77}
78
79static inline void sis96x_write(u8 reg, u8 data)
80{
81 outb(data, sis96x_smbus_base + reg) ;
82}
83
84
85
86
87static int sis96x_transaction(int size)
88{
89 int temp;
90 int result = 0;
91 int timeout = 0;
92
93 dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
94
95
96 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
97
98 dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
99 "Resetting...\n", temp);
100
101
102 sis96x_write(SMB_HOST_CNT, 0x20);
103
104
105 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
106 dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
107 return -EBUSY;
108 } else {
109 dev_dbg(&sis96x_adapter.dev, "Successful\n");
110 }
111 }
112
113
114 sis96x_write(SMB_CNT, 0x20);
115
116
117 temp = sis96x_read(SMB_STS);
118 sis96x_write(SMB_STS, temp & 0x1e);
119
120
121 sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
122
123
124 do {
125 msleep(1);
126 temp = sis96x_read(SMB_STS);
127 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
128
129
130 if (timeout > MAX_TIMEOUT) {
131 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
132 result = -ETIMEDOUT;
133 }
134
135
136 if (temp & 0x02) {
137 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
138 result = -ENXIO;
139 }
140
141
142 if (temp & 0x04) {
143 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
144 result = -EIO;
145 }
146
147
148 sis96x_write(SMB_STS, temp);
149 if ((temp = sis96x_read(SMB_STS))) {
150 dev_dbg(&sis96x_adapter.dev, "Failed reset at "
151 "end of transaction! (0x%02x)\n", temp);
152 }
153
154 return result;
155}
156
157
158static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
159 unsigned short flags, char read_write,
160 u8 command, int size, union i2c_smbus_data * data)
161{
162 int status;
163
164 switch (size) {
165 case I2C_SMBUS_QUICK:
166 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
167 size = SIS96x_QUICK;
168 break;
169
170 case I2C_SMBUS_BYTE:
171 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
172 if (read_write == I2C_SMBUS_WRITE)
173 sis96x_write(SMB_CMD, command);
174 size = SIS96x_BYTE;
175 break;
176
177 case I2C_SMBUS_BYTE_DATA:
178 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
179 sis96x_write(SMB_CMD, command);
180 if (read_write == I2C_SMBUS_WRITE)
181 sis96x_write(SMB_BYTE, data->byte);
182 size = SIS96x_BYTE_DATA;
183 break;
184
185 case I2C_SMBUS_PROC_CALL:
186 case I2C_SMBUS_WORD_DATA:
187 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
188 sis96x_write(SMB_CMD, command);
189 if (read_write == I2C_SMBUS_WRITE) {
190 sis96x_write(SMB_BYTE, data->word & 0xff);
191 sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
192 }
193 size = (size == I2C_SMBUS_PROC_CALL ?
194 SIS96x_PROC_CALL : SIS96x_WORD_DATA);
195 break;
196
197 default:
198 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
199 return -EOPNOTSUPP;
200 }
201
202 status = sis96x_transaction(size);
203 if (status)
204 return status;
205
206 if ((size != SIS96x_PROC_CALL) &&
207 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))
208 return 0;
209
210 switch (size) {
211 case SIS96x_BYTE:
212 case SIS96x_BYTE_DATA:
213 data->byte = sis96x_read(SMB_BYTE);
214 break;
215
216 case SIS96x_WORD_DATA:
217 case SIS96x_PROC_CALL:
218 data->word = sis96x_read(SMB_BYTE) +
219 (sis96x_read(SMB_BYTE + 1) << 8);
220 break;
221 }
222 return 0;
223}
224
225static u32 sis96x_func(struct i2c_adapter *adapter)
226{
227 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
228 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
229 I2C_FUNC_SMBUS_PROC_CALL;
230}
231
232static const struct i2c_algorithm smbus_algorithm = {
233 .smbus_xfer = sis96x_access,
234 .functionality = sis96x_func,
235};
236
237static struct i2c_adapter sis96x_adapter = {
238 .owner = THIS_MODULE,
239 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
240 .algo = &smbus_algorithm,
241};
242
243static const struct pci_device_id sis96x_ids[] = {
244 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
245 { 0, }
246};
247
248MODULE_DEVICE_TABLE (pci, sis96x_ids);
249
250static int sis96x_probe(struct pci_dev *dev,
251 const struct pci_device_id *id)
252{
253 u16 ww = 0;
254 int retval;
255
256 if (sis96x_smbus_base) {
257 dev_err(&dev->dev, "Only one device supported.\n");
258 return -EBUSY;
259 }
260
261 pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww);
262 if (PCI_CLASS_SERIAL_SMBUS != ww) {
263 dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww);
264 return -ENODEV;
265 }
266
267 sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR);
268 if (!sis96x_smbus_base) {
269 dev_err(&dev->dev, "SiS96x SMBus base address "
270 "not initialized!\n");
271 return -EINVAL;
272 }
273 dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n",
274 sis96x_smbus_base);
275
276 retval = acpi_check_resource_conflict(&dev->resource[SIS96x_BAR]);
277 if (retval)
278 return -ENODEV;
279
280
281 if (!request_region(sis96x_smbus_base, SMB_IOSIZE,
282 sis96x_driver.name)) {
283 dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x "
284 "already in use!\n", sis96x_smbus_base,
285 sis96x_smbus_base + SMB_IOSIZE - 1);
286
287 sis96x_smbus_base = 0;
288 return -EINVAL;
289 }
290
291
292 sis96x_adapter.dev.parent = &dev->dev;
293
294 snprintf(sis96x_adapter.name, sizeof(sis96x_adapter.name),
295 "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base);
296
297 if ((retval = i2c_add_adapter(&sis96x_adapter))) {
298 dev_err(&dev->dev, "Couldn't register adapter!\n");
299 release_region(sis96x_smbus_base, SMB_IOSIZE);
300 sis96x_smbus_base = 0;
301 }
302
303 return retval;
304}
305
306static void sis96x_remove(struct pci_dev *dev)
307{
308 if (sis96x_smbus_base) {
309 i2c_del_adapter(&sis96x_adapter);
310 release_region(sis96x_smbus_base, SMB_IOSIZE);
311 sis96x_smbus_base = 0;
312 }
313}
314
315static struct pci_driver sis96x_driver = {
316 .name = "sis96x_smbus",
317 .id_table = sis96x_ids,
318 .probe = sis96x_probe,
319 .remove = sis96x_remove,
320};
321
322module_pci_driver(sis96x_driver);
323
324MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
325MODULE_DESCRIPTION("SiS96x SMBus driver");
326MODULE_LICENSE("GPL");
327