1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>, |
4 | Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>, |
5 | Mark D. Studebaker <mdsxyz123@yahoo.com> |
6 | Copyright (C) 2005 - 2008 Jean Delvare <jdelvare@suse.de> |
7 | |
8 | */ |
9 | |
10 | /* |
11 | Supports the following VIA south bridges: |
12 | |
13 | Chip name PCI ID REV I2C block |
14 | VT82C596A 0x3050 no |
15 | VT82C596B 0x3051 no |
16 | VT82C686A 0x3057 0x30 no |
17 | VT82C686B 0x3057 0x40 yes |
18 | VT8231 0x8235 no? |
19 | VT8233 0x3074 yes |
20 | VT8233A 0x3147 yes? |
21 | VT8235 0x3177 yes |
22 | VT8237R 0x3227 yes |
23 | VT8237A 0x3337 yes |
24 | VT8237S 0x3372 yes |
25 | VT8251 0x3287 yes |
26 | CX700 0x8324 yes |
27 | VX800/VX820 0x8353 yes |
28 | VX855/VX875 0x8409 yes |
29 | |
30 | Note: we assume there can only be one device, with one SMBus interface. |
31 | */ |
32 | |
33 | #include <linux/module.h> |
34 | #include <linux/delay.h> |
35 | #include <linux/pci.h> |
36 | #include <linux/kernel.h> |
37 | #include <linux/stddef.h> |
38 | #include <linux/ioport.h> |
39 | #include <linux/i2c.h> |
40 | #include <linux/init.h> |
41 | #include <linux/acpi.h> |
42 | #include <linux/io.h> |
43 | |
44 | static struct pci_dev *vt596_pdev; |
45 | |
46 | #define SMBBA1 0x90 |
47 | #define SMBBA2 0x80 |
48 | #define SMBBA3 0xD0 |
49 | |
50 | /* SMBus address offsets */ |
51 | static unsigned short vt596_smba; |
52 | #define SMBHSTSTS (vt596_smba + 0) |
53 | #define SMBHSTCNT (vt596_smba + 2) |
54 | #define SMBHSTCMD (vt596_smba + 3) |
55 | #define SMBHSTADD (vt596_smba + 4) |
56 | #define SMBHSTDAT0 (vt596_smba + 5) |
57 | #define SMBHSTDAT1 (vt596_smba + 6) |
58 | #define SMBBLKDAT (vt596_smba + 7) |
59 | |
60 | /* PCI Address Constants */ |
61 | |
62 | /* SMBus data in configuration space can be found in two places, |
63 | We try to select the better one */ |
64 | |
65 | static unsigned short SMBHSTCFG = 0xD2; |
66 | |
67 | /* Other settings */ |
68 | #define MAX_TIMEOUT 500 |
69 | |
70 | /* VT82C596 constants */ |
71 | #define VT596_QUICK 0x00 |
72 | #define VT596_BYTE 0x04 |
73 | #define VT596_BYTE_DATA 0x08 |
74 | #define VT596_WORD_DATA 0x0C |
75 | #define VT596_PROC_CALL 0x10 |
76 | #define VT596_BLOCK_DATA 0x14 |
77 | #define VT596_I2C_BLOCK_DATA 0x34 |
78 | |
79 | |
80 | /* If force is set to anything different from 0, we forcibly enable the |
81 | VT596. DANGEROUS! */ |
82 | static bool force; |
83 | module_param(force, bool, 0); |
84 | MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!" ); |
85 | |
86 | /* If force_addr is set to anything different from 0, we forcibly enable |
87 | the VT596 at the given address. VERY DANGEROUS! */ |
88 | static u16 force_addr; |
89 | module_param_hw(force_addr, ushort, ioport, 0); |
90 | MODULE_PARM_DESC(force_addr, |
91 | "Forcibly enable the SMBus at the given address. " |
92 | "EXTREMELY DANGEROUS!" ); |
93 | |
94 | |
95 | static struct pci_driver vt596_driver; |
96 | static struct i2c_adapter vt596_adapter; |
97 | |
98 | #define FEATURE_I2CBLOCK (1<<0) |
99 | static unsigned int vt596_features; |
100 | |
101 | #ifdef DEBUG |
102 | static void vt596_dump_regs(const char *msg, u8 size) |
103 | { |
104 | dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x " |
105 | "DAT=%02x,%02x\n" , msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT), |
106 | inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), |
107 | inb_p(SMBHSTDAT1)); |
108 | |
109 | if (size == VT596_BLOCK_DATA |
110 | || size == VT596_I2C_BLOCK_DATA) { |
111 | int i; |
112 | |
113 | dev_dbg(&vt596_adapter.dev, "BLK=" ); |
114 | for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++) |
115 | printk("%02x," , inb_p(SMBBLKDAT)); |
116 | printk("\n" ); |
117 | dev_dbg(&vt596_adapter.dev, " " ); |
118 | for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++) |
119 | printk("%02x," , inb_p(SMBBLKDAT)); |
120 | printk("%02x\n" , inb_p(SMBBLKDAT)); |
121 | } |
122 | } |
123 | #else |
124 | static inline void vt596_dump_regs(const char *msg, u8 size) { } |
125 | #endif |
126 | |
127 | /* Return -1 on error, 0 on success */ |
128 | static int vt596_transaction(u8 size) |
129 | { |
130 | int temp; |
131 | int result = 0; |
132 | int timeout = 0; |
133 | |
134 | vt596_dump_regs(msg: "Transaction (pre)" , size); |
135 | |
136 | /* Make sure the SMBus host is ready to start transmitting */ |
137 | if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { |
138 | dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). " |
139 | "Resetting...\n" , temp); |
140 | |
141 | outb_p(value: temp, SMBHSTSTS); |
142 | if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { |
143 | dev_err(&vt596_adapter.dev, "SMBus reset failed! " |
144 | "(0x%02x)\n" , temp); |
145 | return -EBUSY; |
146 | } |
147 | } |
148 | |
149 | /* Start the transaction by setting bit 6 */ |
150 | outb_p(value: 0x40 | size, SMBHSTCNT); |
151 | |
152 | /* We will always wait for a fraction of a second */ |
153 | do { |
154 | msleep(msecs: 1); |
155 | temp = inb_p(SMBHSTSTS); |
156 | } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT)); |
157 | |
158 | /* If the SMBus is still busy, we give up */ |
159 | if (timeout == MAX_TIMEOUT) { |
160 | result = -ETIMEDOUT; |
161 | dev_err(&vt596_adapter.dev, "SMBus timeout!\n" ); |
162 | } |
163 | |
164 | if (temp & 0x10) { |
165 | result = -EIO; |
166 | dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n" , |
167 | size); |
168 | } |
169 | |
170 | if (temp & 0x08) { |
171 | result = -EIO; |
172 | dev_err(&vt596_adapter.dev, "SMBus collision!\n" ); |
173 | } |
174 | |
175 | if (temp & 0x04) { |
176 | result = -ENXIO; |
177 | dev_dbg(&vt596_adapter.dev, "No response\n" ); |
178 | } |
179 | |
180 | /* Resetting status register */ |
181 | if (temp & 0x1F) |
182 | outb_p(value: temp, SMBHSTSTS); |
183 | |
184 | vt596_dump_regs(msg: "Transaction (post)" , size); |
185 | |
186 | return result; |
187 | } |
188 | |
189 | /* Return negative errno on error, 0 on success */ |
190 | static s32 vt596_access(struct i2c_adapter *adap, u16 addr, |
191 | unsigned short flags, char read_write, u8 command, |
192 | int size, union i2c_smbus_data *data) |
193 | { |
194 | int i; |
195 | int status; |
196 | |
197 | switch (size) { |
198 | case I2C_SMBUS_QUICK: |
199 | size = VT596_QUICK; |
200 | break; |
201 | case I2C_SMBUS_BYTE: |
202 | if (read_write == I2C_SMBUS_WRITE) |
203 | outb_p(value: command, SMBHSTCMD); |
204 | size = VT596_BYTE; |
205 | break; |
206 | case I2C_SMBUS_BYTE_DATA: |
207 | outb_p(value: command, SMBHSTCMD); |
208 | if (read_write == I2C_SMBUS_WRITE) |
209 | outb_p(value: data->byte, SMBHSTDAT0); |
210 | size = VT596_BYTE_DATA; |
211 | break; |
212 | case I2C_SMBUS_WORD_DATA: |
213 | outb_p(value: command, SMBHSTCMD); |
214 | if (read_write == I2C_SMBUS_WRITE) { |
215 | outb_p(value: data->word & 0xff, SMBHSTDAT0); |
216 | outb_p(value: (data->word & 0xff00) >> 8, SMBHSTDAT1); |
217 | } |
218 | size = VT596_WORD_DATA; |
219 | break; |
220 | case I2C_SMBUS_PROC_CALL: |
221 | outb_p(value: command, SMBHSTCMD); |
222 | outb_p(value: data->word & 0xff, SMBHSTDAT0); |
223 | outb_p(value: (data->word & 0xff00) >> 8, SMBHSTDAT1); |
224 | size = VT596_PROC_CALL; |
225 | break; |
226 | case I2C_SMBUS_I2C_BLOCK_DATA: |
227 | if (!(vt596_features & FEATURE_I2CBLOCK)) |
228 | goto exit_unsupported; |
229 | if (read_write == I2C_SMBUS_READ) |
230 | outb_p(value: data->block[0], SMBHSTDAT0); |
231 | fallthrough; |
232 | case I2C_SMBUS_BLOCK_DATA: |
233 | outb_p(value: command, SMBHSTCMD); |
234 | if (read_write == I2C_SMBUS_WRITE) { |
235 | u8 len = data->block[0]; |
236 | if (len > I2C_SMBUS_BLOCK_MAX) |
237 | len = I2C_SMBUS_BLOCK_MAX; |
238 | outb_p(value: len, SMBHSTDAT0); |
239 | inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */ |
240 | for (i = 1; i <= len; i++) |
241 | outb_p(value: data->block[i], SMBBLKDAT); |
242 | } |
243 | size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ? |
244 | VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA; |
245 | break; |
246 | default: |
247 | goto exit_unsupported; |
248 | } |
249 | |
250 | outb_p(value: ((addr & 0x7f) << 1) | read_write, SMBHSTADD); |
251 | |
252 | status = vt596_transaction(size); |
253 | if (status) |
254 | return status; |
255 | |
256 | if (size == VT596_PROC_CALL) |
257 | read_write = I2C_SMBUS_READ; |
258 | |
259 | if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK)) |
260 | return 0; |
261 | |
262 | switch (size) { |
263 | case VT596_BYTE: |
264 | case VT596_BYTE_DATA: |
265 | data->byte = inb_p(SMBHSTDAT0); |
266 | break; |
267 | case VT596_WORD_DATA: |
268 | case VT596_PROC_CALL: |
269 | data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8); |
270 | break; |
271 | case VT596_I2C_BLOCK_DATA: |
272 | case VT596_BLOCK_DATA: |
273 | data->block[0] = inb_p(SMBHSTDAT0); |
274 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) |
275 | data->block[0] = I2C_SMBUS_BLOCK_MAX; |
276 | inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */ |
277 | for (i = 1; i <= data->block[0]; i++) |
278 | data->block[i] = inb_p(SMBBLKDAT); |
279 | break; |
280 | } |
281 | return 0; |
282 | |
283 | exit_unsupported: |
284 | dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n" , |
285 | size); |
286 | return -EOPNOTSUPP; |
287 | } |
288 | |
289 | static u32 vt596_func(struct i2c_adapter *adapter) |
290 | { |
291 | u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | |
292 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | |
293 | I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA; |
294 | |
295 | if (vt596_features & FEATURE_I2CBLOCK) |
296 | func |= I2C_FUNC_SMBUS_I2C_BLOCK; |
297 | return func; |
298 | } |
299 | |
300 | static const struct i2c_algorithm smbus_algorithm = { |
301 | .smbus_xfer = vt596_access, |
302 | .functionality = vt596_func, |
303 | }; |
304 | |
305 | static struct i2c_adapter vt596_adapter = { |
306 | .owner = THIS_MODULE, |
307 | .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, |
308 | .algo = &smbus_algorithm, |
309 | }; |
310 | |
311 | static int vt596_probe(struct pci_dev *pdev, |
312 | const struct pci_device_id *id) |
313 | { |
314 | unsigned char temp; |
315 | int error; |
316 | |
317 | /* Determine the address of the SMBus areas */ |
318 | if (force_addr) { |
319 | vt596_smba = force_addr & 0xfff0; |
320 | force = 0; |
321 | goto found; |
322 | } |
323 | |
324 | if ((pci_read_config_word(dev: pdev, where: id->driver_data, val: &vt596_smba)) || |
325 | !(vt596_smba & 0x0001)) { |
326 | /* try 2nd address and config reg. for 596 */ |
327 | if (id->device == PCI_DEVICE_ID_VIA_82C596_3 && |
328 | !pci_read_config_word(dev: pdev, SMBBA2, val: &vt596_smba) && |
329 | (vt596_smba & 0x0001)) { |
330 | SMBHSTCFG = 0x84; |
331 | } else { |
332 | /* no matches at all */ |
333 | dev_err(&pdev->dev, "Cannot configure " |
334 | "SMBus I/O Base address\n" ); |
335 | return -ENODEV; |
336 | } |
337 | } |
338 | |
339 | vt596_smba &= 0xfff0; |
340 | if (vt596_smba == 0) { |
341 | dev_err(&pdev->dev, "SMBus base address " |
342 | "uninitialized - upgrade BIOS or use " |
343 | "force_addr=0xaddr\n" ); |
344 | return -ENODEV; |
345 | } |
346 | |
347 | found: |
348 | error = acpi_check_region(start: vt596_smba, n: 8, name: vt596_driver.name); |
349 | if (error) |
350 | return -ENODEV; |
351 | |
352 | if (!request_region(vt596_smba, 8, vt596_driver.name)) { |
353 | dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n" , |
354 | vt596_smba); |
355 | return -ENODEV; |
356 | } |
357 | |
358 | pci_read_config_byte(dev: pdev, where: SMBHSTCFG, val: &temp); |
359 | /* If force_addr is set, we program the new address here. Just to make |
360 | sure, we disable the VT596 first. */ |
361 | if (force_addr) { |
362 | pci_write_config_byte(dev: pdev, where: SMBHSTCFG, val: temp & 0xfe); |
363 | pci_write_config_word(dev: pdev, where: id->driver_data, val: vt596_smba); |
364 | pci_write_config_byte(dev: pdev, where: SMBHSTCFG, val: temp | 0x01); |
365 | dev_warn(&pdev->dev, "WARNING: SMBus interface set to new " |
366 | "address 0x%04x!\n" , vt596_smba); |
367 | } else if (!(temp & 0x01)) { |
368 | if (force) { |
369 | /* NOTE: This assumes I/O space and other allocations |
370 | * WERE done by the Bios! Don't complain if your |
371 | * hardware does weird things after enabling this. |
372 | * :') Check for Bios updates before resorting to |
373 | * this. |
374 | */ |
375 | pci_write_config_byte(dev: pdev, where: SMBHSTCFG, val: temp | 0x01); |
376 | dev_info(&pdev->dev, "Enabling SMBus device\n" ); |
377 | } else { |
378 | dev_err(&pdev->dev, "SMBUS: Error: Host SMBus " |
379 | "controller not enabled! - upgrade BIOS or " |
380 | "use force=1\n" ); |
381 | error = -ENODEV; |
382 | goto release_region; |
383 | } |
384 | } |
385 | |
386 | dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n" , vt596_smba); |
387 | |
388 | switch (pdev->device) { |
389 | case PCI_DEVICE_ID_VIA_CX700: |
390 | case PCI_DEVICE_ID_VIA_VX800: |
391 | case PCI_DEVICE_ID_VIA_VX855: |
392 | case PCI_DEVICE_ID_VIA_VX900: |
393 | case PCI_DEVICE_ID_VIA_8251: |
394 | case PCI_DEVICE_ID_VIA_8237: |
395 | case PCI_DEVICE_ID_VIA_8237A: |
396 | case PCI_DEVICE_ID_VIA_8237S: |
397 | case PCI_DEVICE_ID_VIA_8235: |
398 | case PCI_DEVICE_ID_VIA_8233A: |
399 | case PCI_DEVICE_ID_VIA_8233_0: |
400 | vt596_features |= FEATURE_I2CBLOCK; |
401 | break; |
402 | case PCI_DEVICE_ID_VIA_82C686_4: |
403 | /* The VT82C686B (rev 0x40) does support I2C block |
404 | transactions, but the VT82C686A (rev 0x30) doesn't */ |
405 | if (pdev->revision >= 0x40) |
406 | vt596_features |= FEATURE_I2CBLOCK; |
407 | break; |
408 | } |
409 | |
410 | vt596_adapter.dev.parent = &pdev->dev; |
411 | snprintf(buf: vt596_adapter.name, size: sizeof(vt596_adapter.name), |
412 | fmt: "SMBus Via Pro adapter at %04x" , vt596_smba); |
413 | |
414 | vt596_pdev = pci_dev_get(dev: pdev); |
415 | error = i2c_add_adapter(adap: &vt596_adapter); |
416 | if (error) { |
417 | pci_dev_put(dev: vt596_pdev); |
418 | vt596_pdev = NULL; |
419 | goto release_region; |
420 | } |
421 | |
422 | /* Always return failure here. This is to allow other drivers to bind |
423 | * to this pci device. We don't really want to have control over the |
424 | * pci device, we only wanted to read as few register values from it. |
425 | */ |
426 | return -ENODEV; |
427 | |
428 | release_region: |
429 | release_region(vt596_smba, 8); |
430 | return error; |
431 | } |
432 | |
433 | static const struct pci_device_id vt596_ids[] = { |
434 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3), |
435 | .driver_data = SMBBA1 }, |
436 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3), |
437 | .driver_data = SMBBA1 }, |
438 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4), |
439 | .driver_data = SMBBA1 }, |
440 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0), |
441 | .driver_data = SMBBA3 }, |
442 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A), |
443 | .driver_data = SMBBA3 }, |
444 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235), |
445 | .driver_data = SMBBA3 }, |
446 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237), |
447 | .driver_data = SMBBA3 }, |
448 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A), |
449 | .driver_data = SMBBA3 }, |
450 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S), |
451 | .driver_data = SMBBA3 }, |
452 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4), |
453 | .driver_data = SMBBA1 }, |
454 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251), |
455 | .driver_data = SMBBA3 }, |
456 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700), |
457 | .driver_data = SMBBA3 }, |
458 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800), |
459 | .driver_data = SMBBA3 }, |
460 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855), |
461 | .driver_data = SMBBA3 }, |
462 | { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX900), |
463 | .driver_data = SMBBA3 }, |
464 | { 0, } |
465 | }; |
466 | |
467 | MODULE_DEVICE_TABLE(pci, vt596_ids); |
468 | |
469 | static struct pci_driver vt596_driver = { |
470 | .name = "vt596_smbus" , |
471 | .id_table = vt596_ids, |
472 | .probe = vt596_probe, |
473 | }; |
474 | |
475 | static int __init i2c_vt596_init(void) |
476 | { |
477 | return pci_register_driver(&vt596_driver); |
478 | } |
479 | |
480 | |
481 | static void __exit i2c_vt596_exit(void) |
482 | { |
483 | pci_unregister_driver(dev: &vt596_driver); |
484 | if (vt596_pdev != NULL) { |
485 | i2c_del_adapter(adap: &vt596_adapter); |
486 | release_region(vt596_smba, 8); |
487 | pci_dev_put(dev: vt596_pdev); |
488 | vt596_pdev = NULL; |
489 | } |
490 | } |
491 | |
492 | MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>" ); |
493 | MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>" ); |
494 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>" ); |
495 | MODULE_DESCRIPTION("vt82c596 SMBus driver" ); |
496 | MODULE_LICENSE("GPL" ); |
497 | |
498 | module_init(i2c_vt596_init); |
499 | module_exit(i2c_vt596_exit); |
500 | |