xref: /linux/drivers/i2c/busses/i2c-nforce2.c (revision 7f4f3b14e8079ecde096bd734af10e30d40c27b7)
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 static void nforce2_abort(struct i2c_adapter *adap)
121 {
122 	struct nforce2_smbus *smbus = adap->algo_data;
123 	int timeout = 0;
124 	unsigned char temp;
125 
126 	dev_dbg(&adap->dev, "Aborting current transaction\n");
127 
128 	outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
129 	do {
130 		msleep(1);
131 		temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
132 	} while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
133 			(timeout++ < MAX_TIMEOUT));
134 	if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
135 		dev_err(&adap->dev, "Can't reset the smbus\n");
136 	outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
137 }
138 
139 static int nforce2_check_status(struct i2c_adapter *adap)
140 {
141 	struct nforce2_smbus *smbus = adap->algo_data;
142 	int timeout = 0;
143 	unsigned char temp;
144 
145 	do {
146 		msleep(1);
147 		temp = inb_p(NVIDIA_SMB_STS);
148 	} while ((!temp) && (timeout++ < MAX_TIMEOUT));
149 
150 	if (timeout > MAX_TIMEOUT) {
151 		dev_dbg(&adap->dev, "SMBus Timeout!\n");
152 		if (smbus->can_abort)
153 			nforce2_abort(adap);
154 		return -ETIMEDOUT;
155 	}
156 	if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
157 		dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
158 		return -EIO;
159 	}
160 	return 0;
161 }
162 
163 /* Return negative errno on error */
164 static s32 nforce2_access(struct i2c_adapter *adap, u16 addr,
165 		unsigned short flags, char read_write,
166 		u8 command, int size, union i2c_smbus_data *data)
167 {
168 	struct nforce2_smbus *smbus = adap->algo_data;
169 	unsigned char protocol, pec;
170 	u8 len;
171 	int i, status;
172 
173 	protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
174 		NVIDIA_SMB_PRTCL_WRITE;
175 	pec = (flags & I2C_CLIENT_PEC) ? NVIDIA_SMB_PRTCL_PEC : 0;
176 
177 	switch (size) {
178 	case I2C_SMBUS_QUICK:
179 		protocol |= NVIDIA_SMB_PRTCL_QUICK;
180 		read_write = I2C_SMBUS_WRITE;
181 		break;
182 
183 	case I2C_SMBUS_BYTE:
184 		if (read_write == I2C_SMBUS_WRITE)
185 			outb_p(command, NVIDIA_SMB_CMD);
186 		protocol |= NVIDIA_SMB_PRTCL_BYTE;
187 		break;
188 
189 	case I2C_SMBUS_BYTE_DATA:
190 		outb_p(command, NVIDIA_SMB_CMD);
191 		if (read_write == I2C_SMBUS_WRITE)
192 			outb_p(data->byte, NVIDIA_SMB_DATA);
193 		protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
194 		break;
195 
196 	case I2C_SMBUS_WORD_DATA:
197 		outb_p(command, NVIDIA_SMB_CMD);
198 		if (read_write == I2C_SMBUS_WRITE) {
199 			outb_p(data->word, NVIDIA_SMB_DATA);
200 			outb_p(data->word >> 8, NVIDIA_SMB_DATA + 1);
201 		}
202 		protocol |= NVIDIA_SMB_PRTCL_WORD_DATA | pec;
203 		break;
204 
205 	case I2C_SMBUS_BLOCK_DATA:
206 		outb_p(command, NVIDIA_SMB_CMD);
207 		if (read_write == I2C_SMBUS_WRITE) {
208 			len = data->block[0];
209 			if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
210 				dev_err(&adap->dev,
211 					"Transaction failed (requested block size: %d)\n",
212 					len);
213 				return -EINVAL;
214 			}
215 			outb_p(len, NVIDIA_SMB_BCNT);
216 			for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
217 				outb_p(data->block[i + 1],
218 				       NVIDIA_SMB_DATA + i);
219 		}
220 		protocol |= NVIDIA_SMB_PRTCL_BLOCK_DATA | pec;
221 		break;
222 
223 	default:
224 		dev_err(&adap->dev, "Unsupported transaction %d\n", size);
225 		return -EOPNOTSUPP;
226 	}
227 
228 	outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
229 	outb_p(protocol, NVIDIA_SMB_PRTCL);
230 
231 	status = nforce2_check_status(adap);
232 	if (status)
233 		return status;
234 
235 	if (read_write == I2C_SMBUS_WRITE)
236 		return 0;
237 
238 	switch (size) {
239 	case I2C_SMBUS_BYTE:
240 	case I2C_SMBUS_BYTE_DATA:
241 		data->byte = inb_p(NVIDIA_SMB_DATA);
242 		break;
243 
244 	case I2C_SMBUS_WORD_DATA:
245 		data->word = inb_p(NVIDIA_SMB_DATA) |
246 			     (inb_p(NVIDIA_SMB_DATA + 1) << 8);
247 		break;
248 
249 	case I2C_SMBUS_BLOCK_DATA:
250 		len = inb_p(NVIDIA_SMB_BCNT);
251 		if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
252 			dev_err(&adap->dev,
253 				"Transaction failed (received block size: 0x%02x)\n",
254 				len);
255 			return -EPROTO;
256 		}
257 		for (i = 0; i < len; i++)
258 			data->block[i + 1] = inb_p(NVIDIA_SMB_DATA + i);
259 		data->block[0] = len;
260 		break;
261 	}
262 
263 	return 0;
264 }
265 
266 
267 static u32 nforce2_func(struct i2c_adapter *adapter)
268 {
269 	/* other functionality might be possible, but is not tested */
270 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
271 	       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
272 	       I2C_FUNC_SMBUS_PEC |
273 	       (((struct nforce2_smbus *)adapter->algo_data)->blockops ?
274 		I2C_FUNC_SMBUS_BLOCK_DATA : 0);
275 }
276 
277 static const struct i2c_algorithm smbus_algorithm = {
278 	.smbus_xfer	= nforce2_access,
279 	.functionality	= nforce2_func,
280 };
281 
282 
283 static const struct pci_device_id nforce2_ids[] = {
284 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
285 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
286 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },
287 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3S_SMBUS) },
288 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE4_SMBUS) },
289 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP04_SMBUS) },
290 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS) },
291 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS) },
292 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP61_SMBUS) },
293 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP65_SMBUS) },
294 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_SMBUS) },
295 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS) },
296 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS) },
297 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS) },
298 	{ 0 }
299 };
300 
301 MODULE_DEVICE_TABLE(pci, nforce2_ids);
302 
303 
304 static int nforce2_probe_smb(struct pci_dev *dev, int bar, int alt_reg,
305 			     struct nforce2_smbus *smbus, const char *name)
306 {
307 	int error;
308 
309 	smbus->base = pci_resource_start(dev, bar);
310 	if (smbus->base) {
311 		smbus->size = pci_resource_len(dev, bar);
312 	} else {
313 		/* Older incarnations of the device used non-standard BARs */
314 		u16 iobase;
315 
316 		error = pci_read_config_word(dev, alt_reg, &iobase);
317 		if (error != PCIBIOS_SUCCESSFUL) {
318 			dev_err(&dev->dev, "Error reading PCI config for %s\n",
319 				name);
320 			return -EIO;
321 		}
322 
323 		smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
324 		smbus->size = 64;
325 	}
326 
327 	error = acpi_check_region(smbus->base, smbus->size,
328 				  nforce2_driver.name);
329 	if (error)
330 		return error;
331 
332 	if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
333 		dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
334 			smbus->base, smbus->base+smbus->size-1, name);
335 		return -EBUSY;
336 	}
337 	smbus->adapter.owner = THIS_MODULE;
338 	smbus->adapter.class = I2C_CLASS_HWMON;
339 	smbus->adapter.algo = &smbus_algorithm;
340 	smbus->adapter.algo_data = smbus;
341 	smbus->adapter.dev.parent = &dev->dev;
342 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
343 		"SMBus nForce2 adapter at %04x", smbus->base);
344 
345 	error = i2c_add_adapter(&smbus->adapter);
346 	if (error) {
347 		release_region(smbus->base, smbus->size);
348 		return error;
349 	}
350 	dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n",
351 		smbus->base);
352 	return 0;
353 }
354 
355 
356 static int nforce2_probe(struct pci_dev *dev, const struct pci_device_id *id)
357 {
358 	struct nforce2_smbus *smbuses;
359 	int res1, res2;
360 
361 	/* we support 2 SMBus adapters */
362 	smbuses = kcalloc(2, sizeof(struct nforce2_smbus), GFP_KERNEL);
363 	if (!smbuses)
364 		return -ENOMEM;
365 	pci_set_drvdata(dev, smbuses);
366 
367 	switch (dev->device) {
368 	case PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS:
369 	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS:
370 	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:
371 		smbuses[0].blockops = 1;
372 		smbuses[1].blockops = 1;
373 		smbuses[0].can_abort = 1;
374 		smbuses[1].can_abort = 1;
375 	}
376 
377 	/* SMBus adapter 1 */
378 	res1 = nforce2_probe_smb(dev, 4, NFORCE_PCI_SMB1, &smbuses[0], "SMB1");
379 	if (res1 < 0)
380 		smbuses[0].base = 0;	/* to have a check value */
381 
382 	/* SMBus adapter 2 */
383 	if (dmi_check_system(nforce2_dmi_blacklist2)) {
384 		dev_err(&dev->dev, "Disabling SMB2 for safety reasons.\n");
385 		res2 = -EPERM;
386 		smbuses[1].base = 0;
387 	} else {
388 		res2 = nforce2_probe_smb(dev, 5, NFORCE_PCI_SMB2, &smbuses[1],
389 					 "SMB2");
390 		if (res2 < 0)
391 			smbuses[1].base = 0;	/* to have a check value */
392 	}
393 
394 	if ((res1 < 0) && (res2 < 0)) {
395 		/* we did not find even one of the SMBuses, so we give up */
396 		kfree(smbuses);
397 		return -ENODEV;
398 	}
399 
400 	return 0;
401 }
402 
403 
404 static void nforce2_remove(struct pci_dev *dev)
405 {
406 	struct nforce2_smbus *smbuses = pci_get_drvdata(dev);
407 
408 	if (smbuses[0].base) {
409 		i2c_del_adapter(&smbuses[0].adapter);
410 		release_region(smbuses[0].base, smbuses[0].size);
411 	}
412 	if (smbuses[1].base) {
413 		i2c_del_adapter(&smbuses[1].adapter);
414 		release_region(smbuses[1].base, smbuses[1].size);
415 	}
416 	kfree(smbuses);
417 }
418 
419 static struct pci_driver nforce2_driver = {
420 	.name		= "nForce2_smbus",
421 	.id_table	= nforce2_ids,
422 	.probe		= nforce2_probe,
423 	.remove		= nforce2_remove,
424 };
425 
426 module_pci_driver(nforce2_driver);
427