xref: /openbmc/linux/drivers/i2c/busses/i2c-viapro.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
37 #include <linux/module.h>
38 #include <linux/delay.h>
39 #include <linux/pci.h>
40 #include <linux/kernel.h>
41 #include <linux/stddef.h>
42 #include <linux/sched.h>
43 #include <linux/ioport.h>
44 #include <linux/i2c.h>
45 #include <linux/init.h>
46 #include <asm/io.h>
47 
48 static struct pci_dev *vt596_pdev;
49 
50 #define SMBBA1	   	 0x90
51 #define SMBBA2     	 0x80
52 #define SMBBA3     	 0xD0
53 
54 /* SMBus address offsets */
55 static unsigned short vt596_smba;
56 #define SMBHSTSTS	(vt596_smba + 0)
57 #define SMBHSLVSTS	(vt596_smba + 1)
58 #define SMBHSTCNT	(vt596_smba + 2)
59 #define SMBHSTCMD	(vt596_smba + 3)
60 #define SMBHSTADD	(vt596_smba + 4)
61 #define SMBHSTDAT0	(vt596_smba + 5)
62 #define SMBHSTDAT1	(vt596_smba + 6)
63 #define SMBBLKDAT	(vt596_smba + 7)
64 #define SMBSLVCNT	(vt596_smba + 8)
65 #define SMBSHDWCMD	(vt596_smba + 9)
66 #define SMBSLVEVT	(vt596_smba + 0xA)
67 #define SMBSLVDAT	(vt596_smba + 0xC)
68 
69 /* PCI Address Constants */
70 
71 /* SMBus data in configuration space can be found in two places,
72    We try to select the better one*/
73 
74 static unsigned short smb_cf_hstcfg = 0xD2;
75 
76 #define SMBHSTCFG   (smb_cf_hstcfg)
77 #define SMBSLVC     (smb_cf_hstcfg + 1)
78 #define SMBSHDW1    (smb_cf_hstcfg + 2)
79 #define SMBSHDW2    (smb_cf_hstcfg + 3)
80 #define SMBREV      (smb_cf_hstcfg + 4)
81 
82 /* Other settings */
83 #define MAX_TIMEOUT	500
84 #define ENABLE_INT9	0
85 
86 /* VT82C596 constants */
87 #define VT596_QUICK      0x00
88 #define VT596_BYTE       0x04
89 #define VT596_BYTE_DATA  0x08
90 #define VT596_WORD_DATA  0x0C
91 #define VT596_BLOCK_DATA 0x14
92 
93 
94 /* If force is set to anything different from 0, we forcibly enable the
95    VT596. DANGEROUS! */
96 static int force;
97 module_param(force, bool, 0);
98 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
99 
100 /* If force_addr is set to anything different from 0, we forcibly enable
101    the VT596 at the given address. VERY DANGEROUS! */
102 static u16 force_addr;
103 module_param(force_addr, ushort, 0);
104 MODULE_PARM_DESC(force_addr,
105 		 "Forcibly enable the SMBus at the given address. "
106 		 "EXTREMELY DANGEROUS!");
107 
108 
109 static struct i2c_adapter vt596_adapter;
110 
111 /* Another internally used function */
112 static int vt596_transaction(void)
113 {
114 	int temp;
115 	int result = 0;
116 	int timeout = 0;
117 
118 	dev_dbg(&vt596_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
119 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
120 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
121 		inb_p(SMBHSTDAT1));
122 
123 	/* Make sure the SMBus host is ready to start transmitting */
124 	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
125 		dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
126 				"Resetting...\n", temp);
127 
128 		outb_p(temp, SMBHSTSTS);
129 		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
130 			dev_dbg(&vt596_adapter.dev, "Failed! (0x%02x)\n", temp);
131 
132 			return -1;
133 		} else {
134 			dev_dbg(&vt596_adapter.dev, "Successfull!\n");
135 		}
136 	}
137 
138 	/* start the transaction by setting bit 6 */
139 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
140 
141 	/* We will always wait for a fraction of a second!
142 	   I don't know if VIA needs this, Intel did  */
143 	do {
144 		msleep(1);
145 		temp = inb_p(SMBHSTSTS);
146 	} while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
147 
148 	/* If the SMBus is still busy, we give up */
149 	if (timeout >= MAX_TIMEOUT) {
150 		result = -1;
151 		dev_dbg(&vt596_adapter.dev, "SMBus Timeout!\n");
152 	}
153 
154 	if (temp & 0x10) {
155 		result = -1;
156 		dev_dbg(&vt596_adapter.dev, "Error: Failed bus transaction\n");
157 	}
158 
159 	if (temp & 0x08) {
160 		result = -1;
161 		dev_info(&vt596_adapter.dev, "Bus collision! SMBus may be "
162 			"locked until next hard\nreset. (sorry!)\n");
163 		/* Clock stops and slave is stuck in mid-transmission */
164 	}
165 
166 	if (temp & 0x04) {
167 		result = -1;
168 		dev_dbg(&vt596_adapter.dev, "Error: no response!\n");
169 	}
170 
171 	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
172 		outb_p(temp, SMBHSTSTS);
173 		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
174 			dev_warn(&vt596_adapter.dev, "Failed reset at end "
175 				 "of transaction (%02x)\n", temp);
176 		}
177 	}
178 
179 	dev_dbg(&vt596_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
180 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
181 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
182 		inb_p(SMBHSTDAT1));
183 
184 	return result;
185 }
186 
187 /* Return -1 on error. */
188 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
189 		unsigned short flags,  char read_write, u8 command,
190 		int size,  union i2c_smbus_data *data)
191 {
192 	int i, len;
193 
194 	switch (size) {
195 	case I2C_SMBUS_PROC_CALL:
196 		dev_info(&vt596_adapter.dev,
197 			 "I2C_SMBUS_PROC_CALL not supported!\n");
198 		return -1;
199 	case I2C_SMBUS_QUICK:
200 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
201 		       SMBHSTADD);
202 		size = VT596_QUICK;
203 		break;
204 	case I2C_SMBUS_BYTE:
205 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
206 		       SMBHSTADD);
207 		if (read_write == I2C_SMBUS_WRITE)
208 			outb_p(command, SMBHSTCMD);
209 		size = VT596_BYTE;
210 		break;
211 	case I2C_SMBUS_BYTE_DATA:
212 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
213 		       SMBHSTADD);
214 		outb_p(command, SMBHSTCMD);
215 		if (read_write == I2C_SMBUS_WRITE)
216 			outb_p(data->byte, SMBHSTDAT0);
217 		size = VT596_BYTE_DATA;
218 		break;
219 	case I2C_SMBUS_WORD_DATA:
220 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
221 		       SMBHSTADD);
222 		outb_p(command, SMBHSTCMD);
223 		if (read_write == I2C_SMBUS_WRITE) {
224 			outb_p(data->word & 0xff, SMBHSTDAT0);
225 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
226 		}
227 		size = VT596_WORD_DATA;
228 		break;
229 	case I2C_SMBUS_BLOCK_DATA:
230 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
231 		       SMBHSTADD);
232 		outb_p(command, SMBHSTCMD);
233 		if (read_write == I2C_SMBUS_WRITE) {
234 			len = data->block[0];
235 			if (len < 0)
236 				len = 0;
237 			if (len > I2C_SMBUS_BLOCK_MAX)
238 				len = I2C_SMBUS_BLOCK_MAX;
239 			outb_p(len, SMBHSTDAT0);
240 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
241 			for (i = 1; i <= len; i++)
242 				outb_p(data->block[i], SMBBLKDAT);
243 		}
244 		size = VT596_BLOCK_DATA;
245 		break;
246 	}
247 
248 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
249 
250 	if (vt596_transaction()) /* Error in transaction */
251 		return -1;
252 
253 	if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
254 		return 0;
255 
256 	switch (size) {
257 	case VT596_BYTE:
258 		/* Where is the result put? I assume here it is in
259 		 * SMBHSTDAT0 but it might just as well be in the
260 		 * SMBHSTCMD. No clue in the docs
261 		 */
262 		data->byte = inb_p(SMBHSTDAT0);
263 		break;
264 	case VT596_BYTE_DATA:
265 		data->byte = inb_p(SMBHSTDAT0);
266 		break;
267 	case VT596_WORD_DATA:
268 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
269 		break;
270 	case VT596_BLOCK_DATA:
271 		data->block[0] = inb_p(SMBHSTDAT0);
272 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
273 			data->block[0] = I2C_SMBUS_BLOCK_MAX;
274 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
275 		for (i = 1; i <= data->block[0]; i++)
276 			data->block[i] = inb_p(SMBBLKDAT);
277 		break;
278 	}
279 	return 0;
280 }
281 
282 static u32 vt596_func(struct i2c_adapter *adapter)
283 {
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_BLOCK_DATA;
287 }
288 
289 static struct i2c_algorithm smbus_algorithm = {
290 	.name		= "Non-I2C SMBus adapter",
291 	.id		= I2C_ALGO_SMBUS,
292 	.smbus_xfer	= vt596_access,
293 	.functionality	= vt596_func,
294 };
295 
296 static struct i2c_adapter vt596_adapter = {
297 	.owner		= THIS_MODULE,
298 	.class		= I2C_CLASS_HWMON,
299 	.algo		= &smbus_algorithm,
300 	.name		= "unset",
301 };
302 
303 static int __devinit vt596_probe(struct pci_dev *pdev,
304 				 const struct pci_device_id *id)
305 {
306 	unsigned char temp;
307 	int error = -ENODEV;
308 
309 	/* Determine the address of the SMBus areas */
310 	if (force_addr) {
311 		vt596_smba = force_addr & 0xfff0;
312 		force = 0;
313 		goto found;
314 	}
315 
316 	if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
317 	    !(vt596_smba & 0x1)) {
318 		/* try 2nd address and config reg. for 596 */
319 		if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
320 		    !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
321 		    (vt596_smba & 0x1)) {
322 			smb_cf_hstcfg = 0x84;
323 		} else {
324 			/* no matches at all */
325 			dev_err(&pdev->dev, "Cannot configure "
326 				"SMBus I/O Base address\n");
327 			return -ENODEV;
328 		}
329 	}
330 
331 	vt596_smba &= 0xfff0;
332 	if (vt596_smba == 0) {
333 		dev_err(&pdev->dev, "SMBus base address "
334 			"uninitialized - upgrade BIOS or use "
335 			"force_addr=0xaddr\n");
336 		return -ENODEV;
337 	}
338 
339  found:
340 	if (!request_region(vt596_smba, 8, "viapro-smbus")) {
341 		dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
342 		        vt596_smba);
343 		return -ENODEV;
344 	}
345 
346 	pci_read_config_byte(pdev, SMBHSTCFG, &temp);
347 	/* If force_addr is set, we program the new address here. Just to make
348 	   sure, we disable the VT596 first. */
349 	if (force_addr) {
350 		pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
351 		pci_write_config_word(pdev, id->driver_data, vt596_smba);
352 		pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
353 		dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
354 		     "address 0x%04x!\n", vt596_smba);
355 	} else if ((temp & 1) == 0) {
356 		if (force) {
357 			/* NOTE: This assumes I/O space and other allocations
358 			 * WERE done by the Bios!  Don't complain if your
359 			 * hardware does weird things after enabling this.
360 			 * :') Check for Bios updates before resorting to
361 			 * this.
362 			 */
363 			pci_write_config_byte(pdev, SMBHSTCFG, temp | 1);
364 			dev_info(&pdev->dev, "Enabling SMBus device\n");
365 		} else {
366 			dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
367 				"controller not enabled! - upgrade BIOS or "
368 				"use force=1\n");
369 			goto release_region;
370 		}
371 	}
372 
373 	if ((temp & 0x0E) == 8)
374 		dev_dbg(&pdev->dev, "using Interrupt 9 for SMBus.\n");
375 	else if ((temp & 0x0E) == 0)
376 		dev_dbg(&pdev->dev, "using Interrupt SMI# for SMBus.\n");
377 	else
378 		dev_dbg(&pdev->dev, "Illegal Interrupt configuration "
379 			"(or code out of date)!\n");
380 
381 	pci_read_config_byte(pdev, SMBREV, &temp);
382 	dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
383 	dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
384 
385 	vt596_adapter.dev.parent = &pdev->dev;
386 	snprintf(vt596_adapter.name, I2C_NAME_SIZE,
387 			"SMBus Via Pro adapter at %04x", vt596_smba);
388 
389 	vt596_pdev = pci_dev_get(pdev);
390 	if (i2c_add_adapter(&vt596_adapter)) {
391 		pci_dev_put(vt596_pdev);
392 		vt596_pdev = NULL;
393 	}
394 
395 	/* Always return failure here.  This is to allow other drivers to bind
396 	 * to this pci device.  We don't really want to have control over the
397 	 * pci device, we only wanted to read as few register values from it.
398 	 */
399 	return -ENODEV;
400 
401  release_region:
402 	release_region(vt596_smba, 8);
403 	return error;
404 }
405 
406 static struct pci_device_id vt596_ids[] = {
407 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
408 	  .driver_data = SMBBA1 },
409 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
410 	  .driver_data = SMBBA1 },
411 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
412 	  .driver_data = SMBBA1 },
413 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
414 	  .driver_data = SMBBA3 },
415 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
416 	  .driver_data = SMBBA3 },
417 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
418 	  .driver_data = SMBBA3 },
419 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
420 	  .driver_data = SMBBA3 },
421 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
422 	  .driver_data = SMBBA1 },
423 	{ 0, }
424 };
425 
426 MODULE_DEVICE_TABLE (pci, vt596_ids);
427 
428 static struct pci_driver vt596_driver = {
429 	.name		= "vt596_smbus",
430 	.id_table	= vt596_ids,
431 	.probe		= vt596_probe,
432 };
433 
434 static int __init i2c_vt596_init(void)
435 {
436 	return pci_register_driver(&vt596_driver);
437 }
438 
439 
440 static void __exit i2c_vt596_exit(void)
441 {
442 	pci_unregister_driver(&vt596_driver);
443 	if (vt596_pdev != NULL) {
444 		i2c_del_adapter(&vt596_adapter);
445 		release_region(vt596_smba, 8);
446 		pci_dev_put(vt596_pdev);
447 		vt596_pdev = NULL;
448 	}
449 }
450 
451 MODULE_AUTHOR(
452     "Frodo Looijaard <frodol@dds.nl> and "
453     "Philip Edelbrock <phil@netroedge.com>");
454 MODULE_DESCRIPTION("vt82c596 SMBus driver");
455 MODULE_LICENSE("GPL");
456 
457 module_init(i2c_vt596_init);
458 module_exit(i2c_vt596_exit);
459