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1/*
2    Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de>
3
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 2 of the License, or
7    (at your option) any later version.
8
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, write to the Free Software
16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17*/
18
19/*
20   Changes:
21   24.08.2002
22   	Fixed the typo in sis630_access (Thanks to Mark M. Hoffman)
23	Changed sis630_transaction.(Thanks to Mark M. Hoffman)
24   18.09.2002
25	Added SIS730 as supported.
26   21.09.2002
27	Added high_clock module option.If this option is set
28	used Host Master Clock 56KHz (default 14KHz).For now we save old Host
29	Master Clock and after transaction completed restore (otherwise
30	it's confuse BIOS and hung Machine).
31   24.09.2002
32	Fixed typo in sis630_access
33	Fixed logical error by restoring of Host Master Clock
34   31.07.2003
35   	Added block data read/write support.
36*/
37
38/*
39   Status: beta
40
41   Supports:
42	SIS 630
43	SIS 730
44
45   Note: we assume there can only be one device, with one SMBus interface.
46*/
47
48#include <linux/kernel.h>
49#include <linux/module.h>
50#include <linux/delay.h>
51#include <linux/pci.h>
52#include <linux/ioport.h>
53#include <linux/init.h>
54#include <linux/i2c.h>
55#include <linux/acpi.h>
56#include <linux/io.h>
57
58/* SIS630 SMBus registers */
59#define SMB_STS			0x80	/* status */
60#define SMB_EN			0x81	/* status enable */
61#define SMB_CNT			0x82
62#define SMBHOST_CNT		0x83
63#define SMB_ADDR		0x84
64#define SMB_CMD			0x85
65#define SMB_PCOUNT		0x86	/* processed count */
66#define SMB_COUNT		0x87
67#define SMB_BYTE		0x88	/* ~0x8F data byte field */
68#define SMBDEV_ADDR		0x90
69#define SMB_DB0			0x91
70#define SMB_DB1			0x92
71#define SMB_SAA			0x93
72
73/* register count for request_region */
74#define SIS630_SMB_IOREGION	20
75
76/* PCI address constants */
77/* acpi base address register  */
78#define SIS630_ACPI_BASE_REG	0x74
79/* bios control register */
80#define SIS630_BIOS_CTL_REG	0x40
81
82/* Other settings */
83#define MAX_TIMEOUT		500
84
85/* SIS630 constants */
86#define SIS630_QUICK		0x00
87#define SIS630_BYTE		0x01
88#define SIS630_BYTE_DATA	0x02
89#define SIS630_WORD_DATA	0x03
90#define SIS630_PCALL		0x04
91#define SIS630_BLOCK_DATA	0x05
92
93static struct pci_driver sis630_driver;
94
95/* insmod parameters */
96static int high_clock;
97static int force;
98module_param(high_clock, bool, 0);
99MODULE_PARM_DESC(high_clock, "Set Host Master Clock to 56KHz (default 14KHz).");
100module_param(force, bool, 0);
101MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
102
103/* acpi base address */
104static unsigned short acpi_base;
105
106/* supported chips */
107static int supported[] = {
108	PCI_DEVICE_ID_SI_630,
109	PCI_DEVICE_ID_SI_730,
110	0 /* terminates the list */
111};
112
113static inline u8 sis630_read(u8 reg)
114{
115	return inb(acpi_base + reg);
116}
117
118static inline void sis630_write(u8 reg, u8 data)
119{
120	outb(data, acpi_base + reg);
121}
122
123static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldclock)
124{
125        int temp;
126
127	/* Make sure the SMBus host is ready to start transmitting. */
128	if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
129		dev_dbg(&adap->dev, "SMBus busy (%02x).Resetting...\n",temp);
130		/* kill smbus transaction */
131		sis630_write(SMBHOST_CNT, 0x20);
132
133		if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
134			dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
135			return -EBUSY;
136                } else {
137			dev_dbg(&adap->dev, "Successful!\n");
138		}
139        }
140
141	/* save old clock, so we can prevent machine for hung */
142	*oldclock = sis630_read(SMB_CNT);
143
144	dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
145
146	/* disable timeout interrupt , set Host Master Clock to 56KHz if requested */
147	if (high_clock)
148		sis630_write(SMB_CNT, 0x20);
149	else
150		sis630_write(SMB_CNT, (*oldclock & ~0x40));
151
152	/* clear all sticky bits */
153	temp = sis630_read(SMB_STS);
154	sis630_write(SMB_STS, temp & 0x1e);
155
156	/* start the transaction by setting bit 4 and size */
157	sis630_write(SMBHOST_CNT,0x10 | (size & 0x07));
158
159	return 0;
160}
161
162static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
163{
164	int temp, result = 0, timeout = 0;
165
166	/* We will always wait for a fraction of a second! */
167	do {
168		msleep(1);
169		temp = sis630_read(SMB_STS);
170		/* check if block transmitted */
171		if (size == SIS630_BLOCK_DATA && (temp & 0x10))
172			break;
173	} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
174
175	/* If the SMBus is still busy, we give up */
176	if (timeout > MAX_TIMEOUT) {
177		dev_dbg(&adap->dev, "SMBus Timeout!\n");
178		result = -ETIMEDOUT;
179	}
180
181	if (temp & 0x02) {
182		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
183		result = -ENXIO;
184	}
185
186	if (temp & 0x04) {
187		dev_err(&adap->dev, "Bus collision!\n");
188		result = -EIO;
189		/*
190		  TBD: Datasheet say:
191		  the software should clear this bit and restart SMBUS operation.
192		  Should we do it or user start request again?
193		*/
194	}
195
196	return result;
197}
198
199static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
200{
201	int temp = 0;
202
203	/* clear all status "sticky" bits */
204	sis630_write(SMB_STS, temp);
205
206	dev_dbg(&adap->dev, "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
207
208	/*
209	 * restore old Host Master Clock if high_clock is set
210	 * and oldclock was not 56KHz
211	 */
212	if (high_clock && !(oldclock & 0x20))
213		sis630_write(SMB_CNT,(sis630_read(SMB_CNT) & ~0x20));
214
215	dev_dbg(&adap->dev, "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
216}
217
218static int sis630_transaction(struct i2c_adapter *adap, int size)
219{
220	int result = 0;
221	u8 oldclock = 0;
222
223	result = sis630_transaction_start(adap, size, &oldclock);
224	if (!result) {
225		result = sis630_transaction_wait(adap, size);
226		sis630_transaction_end(adap, oldclock);
227	}
228
229	return result;
230}
231
232static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *data, int read_write)
233{
234	int i, len = 0, rc = 0;
235	u8 oldclock = 0;
236
237	if (read_write == I2C_SMBUS_WRITE) {
238		len = data->block[0];
239		if (len < 0)
240			len = 0;
241		else if (len > 32)
242			len = 32;
243		sis630_write(SMB_COUNT, len);
244		for (i=1; i <= len; i++) {
245			dev_dbg(&adap->dev, "set data 0x%02x\n", data->block[i]);
246			/* set data */
247			sis630_write(SMB_BYTE+(i-1)%8, data->block[i]);
248			if (i==8 || (len<8 && i==len)) {
249				dev_dbg(&adap->dev, "start trans len=%d i=%d\n",len ,i);
250				/* first transaction */
251				rc = sis630_transaction_start(adap,
252						SIS630_BLOCK_DATA, &oldclock);
253				if (rc)
254					return rc;
255			}
256			else if ((i-1)%8 == 7 || i==len) {
257				dev_dbg(&adap->dev, "trans_wait len=%d i=%d\n",len,i);
258				if (i>8) {
259					dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
260					/*
261					   If this is not first transaction,
262					   we must clear sticky bit.
263					   clear SMBARY_STS
264					*/
265					sis630_write(SMB_STS,0x10);
266				}
267				rc = sis630_transaction_wait(adap,
268						SIS630_BLOCK_DATA);
269				if (rc) {
270					dev_dbg(&adap->dev, "trans_wait failed\n");
271					break;
272				}
273			}
274		}
275	}
276	else {
277		/* read request */
278		data->block[0] = len = 0;
279		rc = sis630_transaction_start(adap,
280				SIS630_BLOCK_DATA, &oldclock);
281		if (rc)
282			return rc;
283		do {
284			rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
285			if (rc) {
286				dev_dbg(&adap->dev, "trans_wait failed\n");
287				break;
288			}
289			/* if this first transaction then read byte count */
290			if (len == 0)
291				data->block[0] = sis630_read(SMB_COUNT);
292
293			/* just to be sure */
294			if (data->block[0] > 32)
295				data->block[0] = 32;
296
297			dev_dbg(&adap->dev, "block data read len=0x%x\n", data->block[0]);
298
299			for (i=0; i < 8 && len < data->block[0]; i++,len++) {
300				dev_dbg(&adap->dev, "read i=%d len=%d\n", i, len);
301				data->block[len+1] = sis630_read(SMB_BYTE+i);
302			}
303
304			dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
305
306			/* clear SMBARY_STS */
307			sis630_write(SMB_STS,0x10);
308		} while(len < data->block[0]);
309	}
310
311	sis630_transaction_end(adap, oldclock);
312
313	return rc;
314}
315
316/* Return negative errno on error. */
317static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
318			 unsigned short flags, char read_write,
319			 u8 command, int size, union i2c_smbus_data *data)
320{
321	int status;
322
323	switch (size) {
324		case I2C_SMBUS_QUICK:
325			sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
326			size = SIS630_QUICK;
327			break;
328		case I2C_SMBUS_BYTE:
329			sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
330			if (read_write == I2C_SMBUS_WRITE)
331				sis630_write(SMB_CMD, command);
332			size = SIS630_BYTE;
333			break;
334		case I2C_SMBUS_BYTE_DATA:
335			sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
336			sis630_write(SMB_CMD, command);
337			if (read_write == I2C_SMBUS_WRITE)
338				sis630_write(SMB_BYTE, data->byte);
339			size = SIS630_BYTE_DATA;
340			break;
341		case I2C_SMBUS_PROC_CALL:
342		case I2C_SMBUS_WORD_DATA:
343			sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
344			sis630_write(SMB_CMD, command);
345			if (read_write == I2C_SMBUS_WRITE) {
346				sis630_write(SMB_BYTE, data->word & 0xff);
347				sis630_write(SMB_BYTE + 1,(data->word & 0xff00) >> 8);
348			}
349			size = (size == I2C_SMBUS_PROC_CALL ? SIS630_PCALL : SIS630_WORD_DATA);
350			break;
351		case I2C_SMBUS_BLOCK_DATA:
352			sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
353			sis630_write(SMB_CMD, command);
354			size = SIS630_BLOCK_DATA;
355			return sis630_block_data(adap, data, read_write);
356		default:
357			dev_warn(&adap->dev, "Unsupported transaction %d\n",
358				 size);
359			return -EOPNOTSUPP;
360	}
361
362	status = sis630_transaction(adap, size);
363	if (status)
364		return status;
365
366	if ((size != SIS630_PCALL) &&
367		((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
368		return 0;
369	}
370
371	switch(size) {
372		case SIS630_BYTE:
373		case SIS630_BYTE_DATA:
374			data->byte = sis630_read(SMB_BYTE);
375			break;
376		case SIS630_PCALL:
377		case SIS630_WORD_DATA:
378			data->word = sis630_read(SMB_BYTE) + (sis630_read(SMB_BYTE + 1) << 8);
379			break;
380	}
381
382	return 0;
383}
384
385static u32 sis630_func(struct i2c_adapter *adapter)
386{
387	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
388		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL |
389		I2C_FUNC_SMBUS_BLOCK_DATA;
390}
391
392static int __devinit sis630_setup(struct pci_dev *sis630_dev)
393{
394	unsigned char b;
395	struct pci_dev *dummy = NULL;
396	int retval = -ENODEV, i;
397
398	/* check for supported SiS devices */
399	for (i=0; supported[i] > 0 ; i++) {
400		if ((dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy)))
401			break; /* found */
402	}
403
404	if (dummy) {
405		pci_dev_put(dummy);
406	}
407        else if (force) {
408		dev_err(&sis630_dev->dev, "WARNING: Can't detect SIS630 compatible device, but "
409			"loading because of force option enabled\n");
410 	}
411	else {
412		return -ENODEV;
413	}
414
415	/*
416	   Enable ACPI first , so we can accsess reg 74-75
417	   in acpi io space and read acpi base addr
418	*/
419	if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
420		dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
421		goto exit;
422	}
423	/* if ACPI already enabled , do nothing */
424	if (!(b & 0x80) &&
425	    pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
426		dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
427		goto exit;
428	}
429
430	/* Determine the ACPI base address */
431	if (pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
432		dev_err(&sis630_dev->dev, "Error: Can't determine ACPI base address\n");
433		goto exit;
434	}
435
436	dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04x\n", acpi_base);
437
438	retval = acpi_check_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION,
439				   sis630_driver.name);
440	if (retval)
441		goto exit;
442
443	/* Everything is happy, let's grab the memory and set things up. */
444	if (!request_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION,
445			    sis630_driver.name)) {
446		dev_err(&sis630_dev->dev, "SMBus registers 0x%04x-0x%04x already "
447			"in use!\n", acpi_base + SMB_STS, acpi_base + SMB_SAA);
448		goto exit;
449	}
450
451	retval = 0;
452
453exit:
454	if (retval)
455		acpi_base = 0;
456	return retval;
457}
458
459
460static const struct i2c_algorithm smbus_algorithm = {
461	.smbus_xfer	= sis630_access,
462	.functionality	= sis630_func,
463};
464
465static struct i2c_adapter sis630_adapter = {
466	.owner		= THIS_MODULE,
467	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
468	.algo		= &smbus_algorithm,
469};
470
471static const struct pci_device_id sis630_ids[] __devinitconst = {
472	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
473	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
474	{ 0, }
475};
476
477MODULE_DEVICE_TABLE (pci, sis630_ids);
478
479static int __devinit sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
480{
481	if (sis630_setup(dev)) {
482		dev_err(&dev->dev, "SIS630 comp. bus not detected, module not inserted.\n");
483		return -ENODEV;
484	}
485
486	/* set up the sysfs linkage to our parent device */
487	sis630_adapter.dev.parent = &dev->dev;
488
489	snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
490		 "SMBus SIS630 adapter at %04x", acpi_base + SMB_STS);
491
492	return i2c_add_adapter(&sis630_adapter);
493}
494
495static void __devexit sis630_remove(struct pci_dev *dev)
496{
497	if (acpi_base) {
498		i2c_del_adapter(&sis630_adapter);
499		release_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION);
500		acpi_base = 0;
501	}
502}
503
504
505static struct pci_driver sis630_driver = {
506	.name		= "sis630_smbus",
507	.id_table	= sis630_ids,
508	.probe		= sis630_probe,
509	.remove		= __devexit_p(sis630_remove),
510};
511
512static int __init i2c_sis630_init(void)
513{
514	return pci_register_driver(&sis630_driver);
515}
516
517
518static void __exit i2c_sis630_exit(void)
519{
520	pci_unregister_driver(&sis630_driver);
521}
522
523
524MODULE_LICENSE("GPL");
525MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
526MODULE_DESCRIPTION("SIS630 SMBus driver");
527
528module_init(i2c_sis630_init);
529module_exit(i2c_sis630_exit);
530