1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 SMBus driver for nVidia nForce2 MCP
4
5 Added nForce3 Pro 150 Thomas Leibold <thomas@plx.com>,
6 Ported to 2.5 Patrick Dreker <patrick@dreker.de>,
7 Copyright (c) 2003 Hans-Frieder Vogt <hfvogt@arcor.de>,
8 Based on
9 SMBus 2.0 driver for AMD-8111 IO-Hub
10 Copyright (c) 2002 Vojtech Pavlik
11
12*/
13
14/*
15 SUPPORTED DEVICES PCI ID
16 nForce2 MCP 0064
17 nForce2 Ultra 400 MCP 0084
18 nForce3 Pro150 MCP 00D4
19 nForce3 250Gb MCP 00E4
20 nForce4 MCP 0052
21 nForce4 MCP-04 0034
22 nForce MCP51 0264
23 nForce MCP55 0368
24 nForce MCP61 03EB
25 nForce MCP65 0446
26 nForce MCP67 0542
27 nForce MCP73 07D8
28 nForce MCP78S 0752
29 nForce MCP79 0AA2
30
31 This driver supports the 2 SMBuses that are included in the MCP of the
32 nForce2/3/4/5xx chipsets.
33*/
34
35/* Note: we assume there can only be one nForce2, with two SMBus interfaces */
36
37#include <linux/module.h>
38#include <linux/pci.h>
39#include <linux/kernel.h>
40#include <linux/stddef.h>
41#include <linux/ioport.h>
42#include <linux/i2c.h>
43#include <linux/delay.h>
44#include <linux/dmi.h>
45#include <linux/acpi.h>
46#include <linux/slab.h>
47#include <linux/io.h>
48
49MODULE_LICENSE("GPL");
50MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
51MODULE_DESCRIPTION("nForce2/3/4/5xx SMBus driver");
52
53
54struct nforce2_smbus {
55 struct i2c_adapter adapter;
56 int base;
57 int size;
58 int blockops;
59 int can_abort;
60};
61
62
63/*
64 * nVidia nForce2 SMBus control register definitions
65 * (Newer incarnations use standard BARs 4 and 5 instead)
66 */
67#define NFORCE_PCI_SMB1 0x50
68#define NFORCE_PCI_SMB2 0x54
69
70
71/*
72 * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
73 */
74#define NVIDIA_SMB_PRTCL (smbus->base + 0x00) /* protocol, PEC */
75#define NVIDIA_SMB_STS (smbus->base + 0x01) /* status */
76#define NVIDIA_SMB_ADDR (smbus->base + 0x02) /* address */
77#define NVIDIA_SMB_CMD (smbus->base + 0x03) /* command */
78#define NVIDIA_SMB_DATA (smbus->base + 0x04) /* 32 data registers */
79#define NVIDIA_SMB_BCNT (smbus->base + 0x24) /* number of data
80 bytes */
81#define NVIDIA_SMB_STATUS_ABRT (smbus->base + 0x3c) /* register used to
82 check the status of
83 the abort command */
84#define NVIDIA_SMB_CTRL (smbus->base + 0x3e) /* control register */
85
86#define NVIDIA_SMB_STATUS_ABRT_STS 0x01 /* Bit to notify that
87 abort succeeded */
88#define NVIDIA_SMB_CTRL_ABORT 0x20
89#define NVIDIA_SMB_STS_DONE 0x80
90#define NVIDIA_SMB_STS_ALRM 0x40
91#define NVIDIA_SMB_STS_RES 0x20
92#define NVIDIA_SMB_STS_STATUS 0x1f
93
94#define NVIDIA_SMB_PRTCL_WRITE 0x00
95#define NVIDIA_SMB_PRTCL_READ 0x01
96#define NVIDIA_SMB_PRTCL_QUICK 0x02
97#define NVIDIA_SMB_PRTCL_BYTE 0x04
98#define NVIDIA_SMB_PRTCL_BYTE_DATA 0x06
99#define NVIDIA_SMB_PRTCL_WORD_DATA 0x08
100#define NVIDIA_SMB_PRTCL_BLOCK_DATA 0x0a
101#define NVIDIA_SMB_PRTCL_PEC 0x80
102
103/* Misc definitions */
104#define MAX_TIMEOUT 100
105
106/* We disable the second SMBus channel on these boards */
107static const struct dmi_system_id nforce2_dmi_blacklist2[] = {
108 {
109 .ident = "DFI Lanparty NF4 Expert",
110 .matches = {
111 DMI_MATCH(DMI_BOARD_VENDOR, "DFI Corp,LTD"),
112 DMI_MATCH(DMI_BOARD_NAME, "LP UT NF4 Expert"),
113 },
114 },
115 { }
116};
117
118static struct pci_driver nforce2_driver;
119
120/* For multiplexing support, we need a global reference to the 1st
121 SMBus channel */
122#if IS_ENABLED(CONFIG_I2C_NFORCE2_S4985)
123struct i2c_adapter *nforce2_smbus;
124EXPORT_SYMBOL_GPL(nforce2_smbus);
125
126static void nforce2_set_reference(struct i2c_adapter *adap)
127{
128 nforce2_smbus = adap;
129}
130#else
131static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
132#endif
133
134static void nforce2_abort(struct i2c_adapter *adap)
135{
136 struct nforce2_smbus *smbus = adap->algo_data;
137 int timeout = 0;
138 unsigned char temp;
139
140 dev_dbg(&adap->dev, "Aborting current transaction\n");
141
142 outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
143 do {
144 msleep(msecs: 1);
145 temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
146 } while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
147 (timeout++ < MAX_TIMEOUT));
148 if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
149 dev_err(&adap->dev, "Can't reset the smbus\n");
150 outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
151}
152
153static int nforce2_check_status(struct i2c_adapter *adap)
154{
155 struct nforce2_smbus *smbus = adap->algo_data;
156 int timeout = 0;
157 unsigned char temp;
158
159 do {
160 msleep(msecs: 1);
161 temp = inb_p(NVIDIA_SMB_STS);
162 } while ((!temp) && (timeout++ < MAX_TIMEOUT));
163
164 if (timeout > MAX_TIMEOUT) {
165 dev_dbg(&adap->dev, "SMBus Timeout!\n");
166 if (smbus->can_abort)
167 nforce2_abort(adap);
168 return -ETIMEDOUT;
169 }
170 if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
171 dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
172 return -EIO;
173 }
174 return 0;
175}
176
177/* Return negative errno on error */
178static s32 nforce2_access(struct i2c_adapter *adap, u16 addr,
179 unsigned short flags, char read_write,
180 u8 command, int size, union i2c_smbus_data *data)
181{
182 struct nforce2_smbus *smbus = adap->algo_data;
183 unsigned char protocol, pec;
184 u8 len;
185 int i, status;
186
187 protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
188 NVIDIA_SMB_PRTCL_WRITE;
189 pec = (flags & I2C_CLIENT_PEC) ? NVIDIA_SMB_PRTCL_PEC : 0;
190
191 switch (size) {
192 case I2C_SMBUS_QUICK:
193 protocol |= NVIDIA_SMB_PRTCL_QUICK;
194 read_write = I2C_SMBUS_WRITE;
195 break;
196
197 case I2C_SMBUS_BYTE:
198 if (read_write == I2C_SMBUS_WRITE)
199 outb_p(value: command, NVIDIA_SMB_CMD);
200 protocol |= NVIDIA_SMB_PRTCL_BYTE;
201 break;
202
203 case I2C_SMBUS_BYTE_DATA:
204 outb_p(value: command, NVIDIA_SMB_CMD);
205 if (read_write == I2C_SMBUS_WRITE)
206 outb_p(value: data->byte, NVIDIA_SMB_DATA);
207 protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
208 break;
209
210 case I2C_SMBUS_WORD_DATA:
211 outb_p(value: command, NVIDIA_SMB_CMD);
212 if (read_write == I2C_SMBUS_WRITE) {
213 outb_p(value: data->word, NVIDIA_SMB_DATA);
214 outb_p(value: data->word >> 8, NVIDIA_SMB_DATA + 1);
215 }
216 protocol |= NVIDIA_SMB_PRTCL_WORD_DATA | pec;
217 break;
218
219 case I2C_SMBUS_BLOCK_DATA:
220 outb_p(value: command, NVIDIA_SMB_CMD);
221 if (read_write == I2C_SMBUS_WRITE) {
222 len = data->block[0];
223 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
224 dev_err(&adap->dev,
225 "Transaction failed (requested block size: %d)\n",
226 len);
227 return -EINVAL;
228 }
229 outb_p(value: len, NVIDIA_SMB_BCNT);
230 for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
231 outb_p(value: data->block[i + 1],
232 NVIDIA_SMB_DATA + i);
233 }
234 protocol |= NVIDIA_SMB_PRTCL_BLOCK_DATA | pec;
235 break;
236
237 default:
238 dev_err(&adap->dev, "Unsupported transaction %d\n", size);
239 return -EOPNOTSUPP;
240 }
241
242 outb_p(value: (addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
243 outb_p(value: protocol, NVIDIA_SMB_PRTCL);
244
245 status = nforce2_check_status(adap);
246 if (status)
247 return status;
248
249 if (read_write == I2C_SMBUS_WRITE)
250 return 0;
251
252 switch (size) {
253 case I2C_SMBUS_BYTE:
254 case I2C_SMBUS_BYTE_DATA:
255 data->byte = inb_p(NVIDIA_SMB_DATA);
256 break;
257
258 case I2C_SMBUS_WORD_DATA:
259 data->word = inb_p(NVIDIA_SMB_DATA) |
260 (inb_p(NVIDIA_SMB_DATA + 1) << 8);
261 break;
262
263 case I2C_SMBUS_BLOCK_DATA:
264 len = inb_p(NVIDIA_SMB_BCNT);
265 if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
266 dev_err(&adap->dev,
267 "Transaction failed (received block size: 0x%02x)\n",
268 len);
269 return -EPROTO;
270 }
271 for (i = 0; i < len; i++)
272 data->block[i + 1] = inb_p(NVIDIA_SMB_DATA + i);
273 data->block[0] = len;
274 break;
275 }
276
277 return 0;
278}
279
280
281static u32 nforce2_func(struct i2c_adapter *adapter)
282{
283 /* other functionality might be possible, but is not tested */
284 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
285 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
286 I2C_FUNC_SMBUS_PEC |
287 (((struct nforce2_smbus *)adapter->algo_data)->blockops ?
288 I2C_FUNC_SMBUS_BLOCK_DATA : 0);
289}
290
291static const struct i2c_algorithm smbus_algorithm = {
292 .smbus_xfer = nforce2_access,
293 .functionality = nforce2_func,
294};
295
296
297static const struct pci_device_id nforce2_ids[] = {
298 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
299 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
300 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },
301 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3S_SMBUS) },
302 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE4_SMBUS) },
303 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP04_SMBUS) },
304 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS) },
305 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS) },
306 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP61_SMBUS) },
307 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP65_SMBUS) },
308 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_SMBUS) },
309 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS) },
310 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS) },
311 { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS) },
312 { 0 }
313};
314
315MODULE_DEVICE_TABLE(pci, nforce2_ids);
316
317
318static int nforce2_probe_smb(struct pci_dev *dev, int bar, int alt_reg,
319 struct nforce2_smbus *smbus, const char *name)
320{
321 int error;
322
323 smbus->base = pci_resource_start(dev, bar);
324 if (smbus->base) {
325 smbus->size = pci_resource_len(dev, bar);
326 } else {
327 /* Older incarnations of the device used non-standard BARs */
328 u16 iobase;
329
330 error = pci_read_config_word(dev, where: alt_reg, val: &iobase);
331 if (error != PCIBIOS_SUCCESSFUL) {
332 dev_err(&dev->dev, "Error reading PCI config for %s\n",
333 name);
334 return -EIO;
335 }
336
337 smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
338 smbus->size = 64;
339 }
340
341 error = acpi_check_region(start: smbus->base, n: smbus->size,
342 name: nforce2_driver.name);
343 if (error)
344 return error;
345
346 if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
347 dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
348 smbus->base, smbus->base+smbus->size-1, name);
349 return -EBUSY;
350 }
351 smbus->adapter.owner = THIS_MODULE;
352 smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
353 smbus->adapter.algo = &smbus_algorithm;
354 smbus->adapter.algo_data = smbus;
355 smbus->adapter.dev.parent = &dev->dev;
356 snprintf(buf: smbus->adapter.name, size: sizeof(smbus->adapter.name),
357 fmt: "SMBus nForce2 adapter at %04x", smbus->base);
358
359 error = i2c_add_adapter(adap: &smbus->adapter);
360 if (error) {
361 release_region(smbus->base, smbus->size);
362 return error;
363 }
364 dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n",
365 smbus->base);
366 return 0;
367}
368
369
370static int nforce2_probe(struct pci_dev *dev, const struct pci_device_id *id)
371{
372 struct nforce2_smbus *smbuses;
373 int res1, res2;
374
375 /* we support 2 SMBus adapters */
376 smbuses = kcalloc(n: 2, size: sizeof(struct nforce2_smbus), GFP_KERNEL);
377 if (!smbuses)
378 return -ENOMEM;
379 pci_set_drvdata(pdev: dev, data: smbuses);
380
381 switch (dev->device) {
382 case PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS:
383 case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS:
384 case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:
385 smbuses[0].blockops = 1;
386 smbuses[1].blockops = 1;
387 smbuses[0].can_abort = 1;
388 smbuses[1].can_abort = 1;
389 }
390
391 /* SMBus adapter 1 */
392 res1 = nforce2_probe_smb(dev, bar: 4, NFORCE_PCI_SMB1, smbus: &smbuses[0], name: "SMB1");
393 if (res1 < 0)
394 smbuses[0].base = 0; /* to have a check value */
395
396 /* SMBus adapter 2 */
397 if (dmi_check_system(list: nforce2_dmi_blacklist2)) {
398 dev_err(&dev->dev, "Disabling SMB2 for safety reasons.\n");
399 res2 = -EPERM;
400 smbuses[1].base = 0;
401 } else {
402 res2 = nforce2_probe_smb(dev, bar: 5, NFORCE_PCI_SMB2, smbus: &smbuses[1],
403 name: "SMB2");
404 if (res2 < 0)
405 smbuses[1].base = 0; /* to have a check value */
406 }
407
408 if ((res1 < 0) && (res2 < 0)) {
409 /* we did not find even one of the SMBuses, so we give up */
410 kfree(objp: smbuses);
411 return -ENODEV;
412 }
413
414 nforce2_set_reference(adap: &smbuses[0].adapter);
415 return 0;
416}
417
418
419static void nforce2_remove(struct pci_dev *dev)
420{
421 struct nforce2_smbus *smbuses = pci_get_drvdata(pdev: dev);
422
423 nforce2_set_reference(NULL);
424 if (smbuses[0].base) {
425 i2c_del_adapter(adap: &smbuses[0].adapter);
426 release_region(smbuses[0].base, smbuses[0].size);
427 }
428 if (smbuses[1].base) {
429 i2c_del_adapter(adap: &smbuses[1].adapter);
430 release_region(smbuses[1].base, smbuses[1].size);
431 }
432 kfree(objp: smbuses);
433}
434
435static struct pci_driver nforce2_driver = {
436 .name = "nForce2_smbus",
437 .id_table = nforce2_ids,
438 .probe = nforce2_probe,
439 .remove = nforce2_remove,
440};
441
442module_pci_driver(nforce2_driver);
443

source code of linux/drivers/i2c/busses/i2c-nforce2.c