xref: /openbmc/linux/drivers/i2c/busses/i2c-nforce2.c (revision afb46f79)
1 /*
2     SMBus driver for nVidia nForce2 MCP
3 
4     Added nForce3 Pro 150  Thomas Leibold <thomas@plx.com>,
5 	Ported to 2.5 Patrick Dreker <patrick@dreker.de>,
6     Copyright (c) 2003  Hans-Frieder Vogt <hfvogt@arcor.de>,
7     Based on
8     SMBus 2.0 driver for AMD-8111 IO-Hub
9     Copyright (c) 2002 Vojtech Pavlik
10 
11     This program is free software; you can redistribute it and/or modify
12     it under the terms of the GNU General Public License as published by
13     the Free Software Foundation; either version 2 of the License, or
14     (at your option) any later version.
15 
16     This program is distributed in the hope that it will be useful,
17     but WITHOUT ANY WARRANTY; without even the implied warranty of
18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19     GNU General Public License for more details.
20 
21     You should have received a copy of the GNU General Public License
22     along with this program; if not, write to the Free Software
23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25 
26 /*
27     SUPPORTED DEVICES		PCI ID
28     nForce2 MCP			0064
29     nForce2 Ultra 400 MCP	0084
30     nForce3 Pro150 MCP		00D4
31     nForce3 250Gb MCP		00E4
32     nForce4 MCP			0052
33     nForce4 MCP-04		0034
34     nForce MCP51		0264
35     nForce MCP55		0368
36     nForce MCP61		03EB
37     nForce MCP65		0446
38     nForce MCP67		0542
39     nForce MCP73		07D8
40     nForce MCP78S		0752
41     nForce MCP79		0AA2
42 
43     This driver supports the 2 SMBuses that are included in the MCP of the
44     nForce2/3/4/5xx chipsets.
45 */
46 
47 /* Note: we assume there can only be one nForce2, with two SMBus interfaces */
48 
49 #include <linux/module.h>
50 #include <linux/pci.h>
51 #include <linux/kernel.h>
52 #include <linux/stddef.h>
53 #include <linux/ioport.h>
54 #include <linux/i2c.h>
55 #include <linux/delay.h>
56 #include <linux/dmi.h>
57 #include <linux/acpi.h>
58 #include <linux/slab.h>
59 #include <linux/io.h>
60 
61 MODULE_LICENSE("GPL");
62 MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
63 MODULE_DESCRIPTION("nForce2/3/4/5xx SMBus driver");
64 
65 
66 struct nforce2_smbus {
67 	struct i2c_adapter adapter;
68 	int base;
69 	int size;
70 	int blockops;
71 	int can_abort;
72 };
73 
74 
75 /*
76  * nVidia nForce2 SMBus control register definitions
77  * (Newer incarnations use standard BARs 4 and 5 instead)
78  */
79 #define NFORCE_PCI_SMB1	0x50
80 #define NFORCE_PCI_SMB2	0x54
81 
82 
83 /*
84  * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
85  */
86 #define NVIDIA_SMB_PRTCL	(smbus->base + 0x00)	/* protocol, PEC */
87 #define NVIDIA_SMB_STS		(smbus->base + 0x01)	/* status */
88 #define NVIDIA_SMB_ADDR		(smbus->base + 0x02)	/* address */
89 #define NVIDIA_SMB_CMD		(smbus->base + 0x03)	/* command */
90 #define NVIDIA_SMB_DATA		(smbus->base + 0x04)	/* 32 data registers */
91 #define NVIDIA_SMB_BCNT		(smbus->base + 0x24)	/* number of data
92 							   bytes */
93 #define NVIDIA_SMB_STATUS_ABRT	(smbus->base + 0x3c)	/* register used to
94 							   check the status of
95 							   the abort command */
96 #define NVIDIA_SMB_CTRL		(smbus->base + 0x3e)	/* control register */
97 
98 #define NVIDIA_SMB_STATUS_ABRT_STS	0x01		/* Bit to notify that
99 							   abort succeeded */
100 #define NVIDIA_SMB_CTRL_ABORT	0x20
101 #define NVIDIA_SMB_STS_DONE	0x80
102 #define NVIDIA_SMB_STS_ALRM	0x40
103 #define NVIDIA_SMB_STS_RES	0x20
104 #define NVIDIA_SMB_STS_STATUS	0x1f
105 
106 #define NVIDIA_SMB_PRTCL_WRITE			0x00
107 #define NVIDIA_SMB_PRTCL_READ			0x01
108 #define NVIDIA_SMB_PRTCL_QUICK			0x02
109 #define NVIDIA_SMB_PRTCL_BYTE			0x04
110 #define NVIDIA_SMB_PRTCL_BYTE_DATA		0x06
111 #define NVIDIA_SMB_PRTCL_WORD_DATA		0x08
112 #define NVIDIA_SMB_PRTCL_BLOCK_DATA		0x0a
113 #define NVIDIA_SMB_PRTCL_PEC			0x80
114 
115 /* Misc definitions */
116 #define MAX_TIMEOUT	100
117 
118 /* We disable the second SMBus channel on these boards */
119 static const struct dmi_system_id nforce2_dmi_blacklist2[] = {
120 	{
121 		.ident = "DFI Lanparty NF4 Expert",
122 		.matches = {
123 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Corp,LTD"),
124 			DMI_MATCH(DMI_BOARD_NAME, "LP UT NF4 Expert"),
125 		},
126 	},
127 	{ }
128 };
129 
130 static struct pci_driver nforce2_driver;
131 
132 /* For multiplexing support, we need a global reference to the 1st
133    SMBus channel */
134 #if defined CONFIG_I2C_NFORCE2_S4985 || defined CONFIG_I2C_NFORCE2_S4985_MODULE
135 struct i2c_adapter *nforce2_smbus;
136 EXPORT_SYMBOL_GPL(nforce2_smbus);
137 
138 static void nforce2_set_reference(struct i2c_adapter *adap)
139 {
140 	nforce2_smbus = adap;
141 }
142 #else
143 static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
144 #endif
145 
146 static void nforce2_abort(struct i2c_adapter *adap)
147 {
148 	struct nforce2_smbus *smbus = adap->algo_data;
149 	int timeout = 0;
150 	unsigned char temp;
151 
152 	dev_dbg(&adap->dev, "Aborting current transaction\n");
153 
154 	outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
155 	do {
156 		msleep(1);
157 		temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
158 	} while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
159 			(timeout++ < MAX_TIMEOUT));
160 	if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
161 		dev_err(&adap->dev, "Can't reset the smbus\n");
162 	outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
163 }
164 
165 static int nforce2_check_status(struct i2c_adapter *adap)
166 {
167 	struct nforce2_smbus *smbus = adap->algo_data;
168 	int timeout = 0;
169 	unsigned char temp;
170 
171 	do {
172 		msleep(1);
173 		temp = inb_p(NVIDIA_SMB_STS);
174 	} while ((!temp) && (timeout++ < MAX_TIMEOUT));
175 
176 	if (timeout > MAX_TIMEOUT) {
177 		dev_dbg(&adap->dev, "SMBus Timeout!\n");
178 		if (smbus->can_abort)
179 			nforce2_abort(adap);
180 		return -ETIMEDOUT;
181 	}
182 	if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
183 		dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
184 		return -EIO;
185 	}
186 	return 0;
187 }
188 
189 /* Return negative errno on error */
190 static s32 nforce2_access(struct i2c_adapter *adap, u16 addr,
191 		unsigned short flags, char read_write,
192 		u8 command, int size, union i2c_smbus_data *data)
193 {
194 	struct nforce2_smbus *smbus = adap->algo_data;
195 	unsigned char protocol, pec;
196 	u8 len;
197 	int i, status;
198 
199 	protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
200 		NVIDIA_SMB_PRTCL_WRITE;
201 	pec = (flags & I2C_CLIENT_PEC) ? NVIDIA_SMB_PRTCL_PEC : 0;
202 
203 	switch (size) {
204 	case I2C_SMBUS_QUICK:
205 		protocol |= NVIDIA_SMB_PRTCL_QUICK;
206 		read_write = I2C_SMBUS_WRITE;
207 		break;
208 
209 	case I2C_SMBUS_BYTE:
210 		if (read_write == I2C_SMBUS_WRITE)
211 			outb_p(command, NVIDIA_SMB_CMD);
212 		protocol |= NVIDIA_SMB_PRTCL_BYTE;
213 		break;
214 
215 	case I2C_SMBUS_BYTE_DATA:
216 		outb_p(command, NVIDIA_SMB_CMD);
217 		if (read_write == I2C_SMBUS_WRITE)
218 			outb_p(data->byte, NVIDIA_SMB_DATA);
219 		protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
220 		break;
221 
222 	case I2C_SMBUS_WORD_DATA:
223 		outb_p(command, NVIDIA_SMB_CMD);
224 		if (read_write == I2C_SMBUS_WRITE) {
225 			outb_p(data->word, NVIDIA_SMB_DATA);
226 			outb_p(data->word >> 8, NVIDIA_SMB_DATA + 1);
227 		}
228 		protocol |= NVIDIA_SMB_PRTCL_WORD_DATA | pec;
229 		break;
230 
231 	case I2C_SMBUS_BLOCK_DATA:
232 		outb_p(command, NVIDIA_SMB_CMD);
233 		if (read_write == I2C_SMBUS_WRITE) {
234 			len = data->block[0];
235 			if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
236 				dev_err(&adap->dev,
237 					"Transaction failed (requested block size: %d)\n",
238 					len);
239 				return -EINVAL;
240 			}
241 			outb_p(len, NVIDIA_SMB_BCNT);
242 			for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
243 				outb_p(data->block[i + 1],
244 				       NVIDIA_SMB_DATA + i);
245 		}
246 		protocol |= NVIDIA_SMB_PRTCL_BLOCK_DATA | pec;
247 		break;
248 
249 	default:
250 		dev_err(&adap->dev, "Unsupported transaction %d\n", size);
251 		return -EOPNOTSUPP;
252 	}
253 
254 	outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
255 	outb_p(protocol, NVIDIA_SMB_PRTCL);
256 
257 	status = nforce2_check_status(adap);
258 	if (status)
259 		return status;
260 
261 	if (read_write == I2C_SMBUS_WRITE)
262 		return 0;
263 
264 	switch (size) {
265 	case I2C_SMBUS_BYTE:
266 	case I2C_SMBUS_BYTE_DATA:
267 		data->byte = inb_p(NVIDIA_SMB_DATA);
268 		break;
269 
270 	case I2C_SMBUS_WORD_DATA:
271 		data->word = inb_p(NVIDIA_SMB_DATA) |
272 			     (inb_p(NVIDIA_SMB_DATA + 1) << 8);
273 		break;
274 
275 	case I2C_SMBUS_BLOCK_DATA:
276 		len = inb_p(NVIDIA_SMB_BCNT);
277 		if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
278 			dev_err(&adap->dev,
279 				"Transaction failed (received block size: 0x%02x)\n",
280 				len);
281 			return -EPROTO;
282 		}
283 		for (i = 0; i < len; i++)
284 			data->block[i + 1] = inb_p(NVIDIA_SMB_DATA + i);
285 		data->block[0] = len;
286 		break;
287 	}
288 
289 	return 0;
290 }
291 
292 
293 static u32 nforce2_func(struct i2c_adapter *adapter)
294 {
295 	/* other functionality might be possible, but is not tested */
296 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
297 	       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
298 	       I2C_FUNC_SMBUS_PEC |
299 	       (((struct nforce2_smbus *)adapter->algo_data)->blockops ?
300 		I2C_FUNC_SMBUS_BLOCK_DATA : 0);
301 }
302 
303 static struct i2c_algorithm smbus_algorithm = {
304 	.smbus_xfer	= nforce2_access,
305 	.functionality	= nforce2_func,
306 };
307 
308 
309 static const struct pci_device_id nforce2_ids[] = {
310 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
311 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
312 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },
313 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3S_SMBUS) },
314 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE4_SMBUS) },
315 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP04_SMBUS) },
316 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS) },
317 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS) },
318 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP61_SMBUS) },
319 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP65_SMBUS) },
320 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_SMBUS) },
321 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS) },
322 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS) },
323 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS) },
324 	{ 0 }
325 };
326 
327 MODULE_DEVICE_TABLE(pci, nforce2_ids);
328 
329 
330 static int nforce2_probe_smb(struct pci_dev *dev, int bar, int alt_reg,
331 			     struct nforce2_smbus *smbus, const char *name)
332 {
333 	int error;
334 
335 	smbus->base = pci_resource_start(dev, bar);
336 	if (smbus->base) {
337 		smbus->size = pci_resource_len(dev, bar);
338 	} else {
339 		/* Older incarnations of the device used non-standard BARs */
340 		u16 iobase;
341 
342 		if (pci_read_config_word(dev, alt_reg, &iobase)
343 		    != PCIBIOS_SUCCESSFUL) {
344 			dev_err(&dev->dev, "Error reading PCI config for %s\n",
345 				name);
346 			return -EIO;
347 		}
348 
349 		smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
350 		smbus->size = 64;
351 	}
352 
353 	error = acpi_check_region(smbus->base, smbus->size,
354 				  nforce2_driver.name);
355 	if (error)
356 		return error;
357 
358 	if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
359 		dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
360 			smbus->base, smbus->base+smbus->size-1, name);
361 		return -EBUSY;
362 	}
363 	smbus->adapter.owner = THIS_MODULE;
364 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
365 	smbus->adapter.algo = &smbus_algorithm;
366 	smbus->adapter.algo_data = smbus;
367 	smbus->adapter.dev.parent = &dev->dev;
368 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
369 		"SMBus nForce2 adapter at %04x", smbus->base);
370 
371 	error = i2c_add_adapter(&smbus->adapter);
372 	if (error) {
373 		dev_err(&smbus->adapter.dev, "Failed to register adapter.\n");
374 		release_region(smbus->base, smbus->size);
375 		return error;
376 	}
377 	dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n",
378 		smbus->base);
379 	return 0;
380 }
381 
382 
383 static int nforce2_probe(struct pci_dev *dev, const struct pci_device_id *id)
384 {
385 	struct nforce2_smbus *smbuses;
386 	int res1, res2;
387 
388 	/* we support 2 SMBus adapters */
389 	smbuses = kzalloc(2 * sizeof(struct nforce2_smbus), GFP_KERNEL);
390 	if (!smbuses)
391 		return -ENOMEM;
392 	pci_set_drvdata(dev, smbuses);
393 
394 	switch (dev->device) {
395 	case PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS:
396 	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS:
397 	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:
398 		smbuses[0].blockops = 1;
399 		smbuses[1].blockops = 1;
400 		smbuses[0].can_abort = 1;
401 		smbuses[1].can_abort = 1;
402 	}
403 
404 	/* SMBus adapter 1 */
405 	res1 = nforce2_probe_smb(dev, 4, NFORCE_PCI_SMB1, &smbuses[0], "SMB1");
406 	if (res1 < 0)
407 		smbuses[0].base = 0;	/* to have a check value */
408 
409 	/* SMBus adapter 2 */
410 	if (dmi_check_system(nforce2_dmi_blacklist2)) {
411 		dev_err(&dev->dev, "Disabling SMB2 for safety reasons.\n");
412 		res2 = -EPERM;
413 		smbuses[1].base = 0;
414 	} else {
415 		res2 = nforce2_probe_smb(dev, 5, NFORCE_PCI_SMB2, &smbuses[1],
416 					 "SMB2");
417 		if (res2 < 0)
418 			smbuses[1].base = 0;	/* to have a check value */
419 	}
420 
421 	if ((res1 < 0) && (res2 < 0)) {
422 		/* we did not find even one of the SMBuses, so we give up */
423 		kfree(smbuses);
424 		return -ENODEV;
425 	}
426 
427 	nforce2_set_reference(&smbuses[0].adapter);
428 	return 0;
429 }
430 
431 
432 static void nforce2_remove(struct pci_dev *dev)
433 {
434 	struct nforce2_smbus *smbuses = pci_get_drvdata(dev);
435 
436 	nforce2_set_reference(NULL);
437 	if (smbuses[0].base) {
438 		i2c_del_adapter(&smbuses[0].adapter);
439 		release_region(smbuses[0].base, smbuses[0].size);
440 	}
441 	if (smbuses[1].base) {
442 		i2c_del_adapter(&smbuses[1].adapter);
443 		release_region(smbuses[1].base, smbuses[1].size);
444 	}
445 	kfree(smbuses);
446 }
447 
448 static struct pci_driver nforce2_driver = {
449 	.name		= "nForce2_smbus",
450 	.id_table	= nforce2_ids,
451 	.probe		= nforce2_probe,
452 	.remove		= nforce2_remove,
453 };
454 
455 module_pci_driver(nforce2_driver);
456