xref: /linux/drivers/i2c/busses/i2c-viapro.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
1 /*
2     i2c-viapro.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4     Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
5     Philip Edelbrock <phil@netroedge.com>, Ky�sti M�lkki <kmalkki@cc.hut.fi>,
6     Mark D. Studebaker <mdsxyz123@yahoo.com>
7 
8     This program is free software; you can redistribute it and/or modify
9     it under the terms of the GNU General Public License as published by
10     the Free Software Foundation; either version 2 of the License, or
11     (at your option) any later version.
12 
13     This program is distributed in the hope that it will be useful,
14     but WITHOUT ANY WARRANTY; without even the implied warranty of
15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16     GNU General Public License for more details.
17 
18     You should have received a copy of the GNU General Public License
19     along with this program; if not, write to the Free Software
20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22 
23 /*
24    Supports Via devices:
25 	82C596A/B (0x3050)
26 	82C596B (0x3051)
27 	82C686A/B
28 	8231
29 	8233
30 	8233A (0x3147 and 0x3177)
31 	8235
32 	8237
33    Note: we assume there can only be one device, with one SMBus interface.
34 */
35 
36 #include <linux/module.h>
37 #include <linux/delay.h>
38 #include <linux/pci.h>
39 #include <linux/kernel.h>
40 #include <linux/stddef.h>
41 #include <linux/sched.h>
42 #include <linux/ioport.h>
43 #include <linux/i2c.h>
44 #include <linux/init.h>
45 #include <asm/io.h>
46 
47 static struct pci_dev *vt596_pdev;
48 
49 #define SMBBA1	   	 0x90
50 #define SMBBA2     	 0x80
51 #define SMBBA3     	 0xD0
52 
53 /* SMBus address offsets */
54 static unsigned short vt596_smba;
55 #define SMBHSTSTS	(vt596_smba + 0)
56 #define SMBHSLVSTS	(vt596_smba + 1)
57 #define SMBHSTCNT	(vt596_smba + 2)
58 #define SMBHSTCMD	(vt596_smba + 3)
59 #define SMBHSTADD	(vt596_smba + 4)
60 #define SMBHSTDAT0	(vt596_smba + 5)
61 #define SMBHSTDAT1	(vt596_smba + 6)
62 #define SMBBLKDAT	(vt596_smba + 7)
63 #define SMBSLVCNT	(vt596_smba + 8)
64 #define SMBSHDWCMD	(vt596_smba + 9)
65 #define SMBSLVEVT	(vt596_smba + 0xA)
66 #define SMBSLVDAT	(vt596_smba + 0xC)
67 
68 /* PCI Address Constants */
69 
70 /* SMBus data in configuration space can be found in two places,
71    We try to select the better one*/
72 
73 static unsigned short smb_cf_hstcfg = 0xD2;
74 
75 #define SMBHSTCFG   (smb_cf_hstcfg)
76 #define SMBSLVC     (smb_cf_hstcfg + 1)
77 #define SMBSHDW1    (smb_cf_hstcfg + 2)
78 #define SMBSHDW2    (smb_cf_hstcfg + 3)
79 #define SMBREV      (smb_cf_hstcfg + 4)
80 
81 /* Other settings */
82 #define MAX_TIMEOUT	500
83 #define ENABLE_INT9	0
84 
85 /* VT82C596 constants */
86 #define VT596_QUICK      0x00
87 #define VT596_BYTE       0x04
88 #define VT596_BYTE_DATA  0x08
89 #define VT596_WORD_DATA  0x0C
90 #define VT596_BLOCK_DATA 0x14
91 
92 
93 /* If force is set to anything different from 0, we forcibly enable the
94    VT596. DANGEROUS! */
95 static int force;
96 module_param(force, bool, 0);
97 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
98 
99 /* If force_addr is set to anything different from 0, we forcibly enable
100    the VT596 at the given address. VERY DANGEROUS! */
101 static u16 force_addr;
102 module_param(force_addr, ushort, 0);
103 MODULE_PARM_DESC(force_addr,
104 		 "Forcibly enable the SMBus at the given address. "
105 		 "EXTREMELY DANGEROUS!");
106 
107 
108 static struct i2c_adapter vt596_adapter;
109 
110 /* Another internally used function */
111 static int vt596_transaction(void)
112 {
113 	int temp;
114 	int result = 0;
115 	int timeout = 0;
116 
117 	dev_dbg(&vt596_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
118 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
119 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
120 		inb_p(SMBHSTDAT1));
121 
122 	/* Make sure the SMBus host is ready to start transmitting */
123 	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
124 		dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
125 				"Resetting...\n", temp);
126 
127 		outb_p(temp, SMBHSTSTS);
128 		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
129 			dev_dbg(&vt596_adapter.dev, "Failed! (0x%02x)\n", temp);
130 
131 			return -1;
132 		} else {
133 			dev_dbg(&vt596_adapter.dev, "Successfull!\n");
134 		}
135 	}
136 
137 	/* start the transaction by setting bit 6 */
138 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
139 
140 	/* We will always wait for a fraction of a second!
141 	   I don't know if VIA needs this, Intel did  */
142 	do {
143 		msleep(1);
144 		temp = inb_p(SMBHSTSTS);
145 	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
146 
147 	/* If the SMBus is still busy, we give up */
148 	if (timeout >= MAX_TIMEOUT) {
149 		result = -1;
150 		dev_dbg(&vt596_adapter.dev, "SMBus Timeout!\n");
151 	}
152 
153 	if (temp & 0x10) {
154 		result = -1;
155 		dev_dbg(&vt596_adapter.dev, "Error: Failed bus transaction\n");
156 	}
157 
158 	if (temp & 0x08) {
159 		result = -1;
160 		dev_info(&vt596_adapter.dev, "Bus collision! SMBus may be "
161 			"locked until next hard\nreset. (sorry!)\n");
162 		/* Clock stops and slave is stuck in mid-transmission */
163 	}
164 
165 	if (temp & 0x04) {
166 		result = -1;
167 		dev_dbg(&vt596_adapter.dev, "Error: no response!\n");
168 	}
169 
170 	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
171 		outb_p(temp, SMBHSTSTS);
172 		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
173 			dev_warn(&vt596_adapter.dev, "Failed reset at end "
174 				 "of transaction (%02x)\n", temp);
175 		}
176 	}
177 
178 	dev_dbg(&vt596_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
179 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
180 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
181 		inb_p(SMBHSTDAT1));
182 
183 	return result;
184 }
185 
186 /* Return -1 on error. */
187 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
188 		unsigned short flags,  char read_write, u8 command,
189 		int size,  union i2c_smbus_data *data)
190 {
191 	int i, len;
192 
193 	switch (size) {
194 	case I2C_SMBUS_PROC_CALL:
195 		dev_info(&vt596_adapter.dev,
196 			 "I2C_SMBUS_PROC_CALL not supported!\n");
197 		return -1;
198 	case I2C_SMBUS_QUICK:
199 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
200 		       SMBHSTADD);
201 		size = VT596_QUICK;
202 		break;
203 	case I2C_SMBUS_BYTE:
204 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
205 		       SMBHSTADD);
206 		if (read_write == I2C_SMBUS_WRITE)
207 			outb_p(command, SMBHSTCMD);
208 		size = VT596_BYTE;
209 		break;
210 	case I2C_SMBUS_BYTE_DATA:
211 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
212 		       SMBHSTADD);
213 		outb_p(command, SMBHSTCMD);
214 		if (read_write == I2C_SMBUS_WRITE)
215 			outb_p(data->byte, SMBHSTDAT0);
216 		size = VT596_BYTE_DATA;
217 		break;
218 	case I2C_SMBUS_WORD_DATA:
219 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
220 		       SMBHSTADD);
221 		outb_p(command, SMBHSTCMD);
222 		if (read_write == I2C_SMBUS_WRITE) {
223 			outb_p(data->word & 0xff, SMBHSTDAT0);
224 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
225 		}
226 		size = VT596_WORD_DATA;
227 		break;
228 	case I2C_SMBUS_BLOCK_DATA:
229 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
230 		       SMBHSTADD);
231 		outb_p(command, SMBHSTCMD);
232 		if (read_write == I2C_SMBUS_WRITE) {
233 			len = data->block[0];
234 			if (len < 0)
235 				len = 0;
236 			if (len > I2C_SMBUS_BLOCK_MAX)
237 				len = I2C_SMBUS_BLOCK_MAX;
238 			outb_p(len, SMBHSTDAT0);
239 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
240 			for (i = 1; i <= len; i++)
241 				outb_p(data->block[i], SMBBLKDAT);
242 		}
243 		size = VT596_BLOCK_DATA;
244 		break;
245 	}
246 
247 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
248 
249 	if (vt596_transaction()) /* Error in transaction */
250 		return -1;
251 
252 	if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
253 		return 0;
254 
255 	switch (size) {
256 	case VT596_BYTE:
257 		/* Where is the result put? I assume here it is in
258 		 * SMBHSTDAT0 but it might just as well be in the
259 		 * SMBHSTCMD. No clue in the docs
260 		 */
261 		data->byte = inb_p(SMBHSTDAT0);
262 		break;
263 	case VT596_BYTE_DATA:
264 		data->byte = inb_p(SMBHSTDAT0);
265 		break;
266 	case VT596_WORD_DATA:
267 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
268 		break;
269 	case VT596_BLOCK_DATA:
270 		data->block[0] = inb_p(SMBHSTDAT0);
271 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
272 			data->block[0] = I2C_SMBUS_BLOCK_MAX;
273 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
274 		for (i = 1; i <= data->block[0]; i++)
275 			data->block[i] = inb_p(SMBBLKDAT);
276 		break;
277 	}
278 	return 0;
279 }
280 
281 static u32 vt596_func(struct i2c_adapter *adapter)
282 {
283 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
284 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
285 	    I2C_FUNC_SMBUS_BLOCK_DATA;
286 }
287 
288 static struct i2c_algorithm smbus_algorithm = {
289 	.smbus_xfer	= vt596_access,
290 	.functionality	= vt596_func,
291 };
292 
293 static struct i2c_adapter vt596_adapter = {
294 	.owner		= THIS_MODULE,
295 	.class		= I2C_CLASS_HWMON,
296 	.algo		= &smbus_algorithm,
297 	.name		= "unset",
298 };
299 
300 static int __devinit vt596_probe(struct pci_dev *pdev,
301 				 const struct pci_device_id *id)
302 {
303 	unsigned char temp;
304 	int error = -ENODEV;
305 
306 	/* Determine the address of the SMBus areas */
307 	if (force_addr) {
308 		vt596_smba = force_addr & 0xfff0;
309 		force = 0;
310 		goto found;
311 	}
312 
313 	if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
314 	    !(vt596_smba & 0x1)) {
315 		/* try 2nd address and config reg. for 596 */
316 		if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
317 		    !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
318 		    (vt596_smba & 0x1)) {
319 			smb_cf_hstcfg = 0x84;
320 		} else {
321 			/* no matches at all */
322 			dev_err(&pdev->dev, "Cannot configure "
323 				"SMBus I/O Base address\n");
324 			return -ENODEV;
325 		}
326 	}
327 
328 	vt596_smba &= 0xfff0;
329 	if (vt596_smba == 0) {
330 		dev_err(&pdev->dev, "SMBus base address "
331 			"uninitialized - upgrade BIOS or use "
332 			"force_addr=0xaddr\n");
333 		return -ENODEV;
334 	}
335 
336  found:
337 	if (!request_region(vt596_smba, 8, "viapro-smbus")) {
338 		dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
339 		        vt596_smba);
340 		return -ENODEV;
341 	}
342 
343 	pci_read_config_byte(pdev, SMBHSTCFG, &temp);
344 	/* If force_addr is set, we program the new address here. Just to make
345 	   sure, we disable the VT596 first. */
346 	if (force_addr) {
347 		pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
348 		pci_write_config_word(pdev, id->driver_data, vt596_smba);
349 		pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
350 		dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
351 		     "address 0x%04x!\n", vt596_smba);
352 	} else if ((temp & 1) == 0) {
353 		if (force) {
354 			/* NOTE: This assumes I/O space and other allocations
355 			 * WERE done by the Bios!  Don't complain if your
356 			 * hardware does weird things after enabling this.
357 			 * :') Check for Bios updates before resorting to
358 			 * this.
359 			 */
360 			pci_write_config_byte(pdev, SMBHSTCFG, temp | 1);
361 			dev_info(&pdev->dev, "Enabling SMBus device\n");
362 		} else {
363 			dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
364 				"controller not enabled! - upgrade BIOS or "
365 				"use force=1\n");
366 			goto release_region;
367 		}
368 	}
369 
370 	if ((temp & 0x0E) == 8)
371 		dev_dbg(&pdev->dev, "using Interrupt 9 for SMBus.\n");
372 	else if ((temp & 0x0E) == 0)
373 		dev_dbg(&pdev->dev, "using Interrupt SMI# for SMBus.\n");
374 	else
375 		dev_dbg(&pdev->dev, "Illegal Interrupt configuration "
376 			"(or code out of date)!\n");
377 
378 	pci_read_config_byte(pdev, SMBREV, &temp);
379 	dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
380 	dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
381 
382 	vt596_adapter.dev.parent = &pdev->dev;
383 	snprintf(vt596_adapter.name, I2C_NAME_SIZE,
384 			"SMBus Via Pro adapter at %04x", vt596_smba);
385 
386 	vt596_pdev = pci_dev_get(pdev);
387 	if (i2c_add_adapter(&vt596_adapter)) {
388 		pci_dev_put(vt596_pdev);
389 		vt596_pdev = NULL;
390 	}
391 
392 	/* Always return failure here.  This is to allow other drivers to bind
393 	 * to this pci device.  We don't really want to have control over the
394 	 * pci device, we only wanted to read as few register values from it.
395 	 */
396 	return -ENODEV;
397 
398  release_region:
399 	release_region(vt596_smba, 8);
400 	return error;
401 }
402 
403 static struct pci_device_id vt596_ids[] = {
404 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
405 	  .driver_data = SMBBA1 },
406 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
407 	  .driver_data = SMBBA1 },
408 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
409 	  .driver_data = SMBBA1 },
410 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
411 	  .driver_data = SMBBA3 },
412 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
413 	  .driver_data = SMBBA3 },
414 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
415 	  .driver_data = SMBBA3 },
416 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
417 	  .driver_data = SMBBA3 },
418 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
419 	  .driver_data = SMBBA1 },
420 	{ 0, }
421 };
422 
423 MODULE_DEVICE_TABLE (pci, vt596_ids);
424 
425 static struct pci_driver vt596_driver = {
426 	.name		= "vt596_smbus",
427 	.id_table	= vt596_ids,
428 	.probe		= vt596_probe,
429 };
430 
431 static int __init i2c_vt596_init(void)
432 {
433 	return pci_register_driver(&vt596_driver);
434 }
435 
436 
437 static void __exit i2c_vt596_exit(void)
438 {
439 	pci_unregister_driver(&vt596_driver);
440 	if (vt596_pdev != NULL) {
441 		i2c_del_adapter(&vt596_adapter);
442 		release_region(vt596_smba, 8);
443 		pci_dev_put(vt596_pdev);
444 		vt596_pdev = NULL;
445 	}
446 }
447 
448 MODULE_AUTHOR(
449     "Frodo Looijaard <frodol@dds.nl> and "
450     "Philip Edelbrock <phil@netroedge.com>");
451 MODULE_DESCRIPTION("vt82c596 SMBus driver");
452 MODULE_LICENSE("GPL");
453 
454 module_init(i2c_vt596_init);
455 module_exit(i2c_vt596_exit);
456