xref: /openbmc/linux/drivers/i2c/busses/i2c-nforce2.c (revision fe4549b1)
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 
49 MODULE_LICENSE("GPL");
50 MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
51 MODULE_DESCRIPTION("nForce2/3/4/5xx SMBus driver");
52 
53 
54 struct 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 */
107 static 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 
118 static 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)
123 struct i2c_adapter *nforce2_smbus;
124 EXPORT_SYMBOL_GPL(nforce2_smbus);
125 
126 static void nforce2_set_reference(struct i2c_adapter *adap)
127 {
128 	nforce2_smbus = adap;
129 }
130 #else
131 static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
132 #endif
133 
134 static 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(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 
153 static 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(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 */
178 static 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(command, NVIDIA_SMB_CMD);
200 		protocol |= NVIDIA_SMB_PRTCL_BYTE;
201 		break;
202 
203 	case I2C_SMBUS_BYTE_DATA:
204 		outb_p(command, NVIDIA_SMB_CMD);
205 		if (read_write == I2C_SMBUS_WRITE)
206 			outb_p(data->byte, NVIDIA_SMB_DATA);
207 		protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
208 		break;
209 
210 	case I2C_SMBUS_WORD_DATA:
211 		outb_p(command, NVIDIA_SMB_CMD);
212 		if (read_write == I2C_SMBUS_WRITE) {
213 			outb_p(data->word, NVIDIA_SMB_DATA);
214 			outb_p(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(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(len, NVIDIA_SMB_BCNT);
230 			for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
231 				outb_p(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((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
243 	outb_p(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 
281 static 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 
291 static const struct i2c_algorithm smbus_algorithm = {
292 	.smbus_xfer	= nforce2_access,
293 	.functionality	= nforce2_func,
294 };
295 
296 
297 static 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 
315 MODULE_DEVICE_TABLE(pci, nforce2_ids);
316 
317 
318 static 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, alt_reg, &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(smbus->base, smbus->size,
342 				  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(smbus->adapter.name, sizeof(smbus->adapter.name),
357 		"SMBus nForce2 adapter at %04x", smbus->base);
358 
359 	error = i2c_add_adapter(&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 
370 static 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(2, sizeof(struct nforce2_smbus), GFP_KERNEL);
377 	if (!smbuses)
378 		return -ENOMEM;
379 	pci_set_drvdata(dev, 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, 4, NFORCE_PCI_SMB1, &smbuses[0], "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(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, 5, NFORCE_PCI_SMB2, &smbuses[1],
403 					 "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(smbuses);
411 		return -ENODEV;
412 	}
413 
414 	nforce2_set_reference(&smbuses[0].adapter);
415 	return 0;
416 }
417 
418 
419 static void nforce2_remove(struct pci_dev *dev)
420 {
421 	struct nforce2_smbus *smbuses = pci_get_drvdata(dev);
422 
423 	nforce2_set_reference(NULL);
424 	if (smbuses[0].base) {
425 		i2c_del_adapter(&smbuses[0].adapter);
426 		release_region(smbuses[0].base, smbuses[0].size);
427 	}
428 	if (smbuses[1].base) {
429 		i2c_del_adapter(&smbuses[1].adapter);
430 		release_region(smbuses[1].base, smbuses[1].size);
431 	}
432 	kfree(smbuses);
433 }
434 
435 static struct pci_driver nforce2_driver = {
436 	.name		= "nForce2_smbus",
437 	.id_table	= nforce2_ids,
438 	.probe		= nforce2_probe,
439 	.remove		= nforce2_remove,
440 };
441 
442 module_pci_driver(nforce2_driver);
443