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1/*
2    Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
3                        Philip Edelbrock <phil@netroedge.com>,
4                        Mark D. Studebaker <mdsxyz123@yahoo.com>,
5                        Dan Eaton <dan.eaton@rocketlogix.com> and
6                        Stephen Rousset<stephen.rousset@rocketlogix.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    This is the driver for the SMB Host controller on
25    Acer Labs Inc. (ALI) M1535 South Bridge.
26
27    The M1535 is a South bridge for portable systems.
28    It is very similar to the M15x3 South bridges also produced
29    by Acer Labs Inc.  Some of the registers within the part
30    have moved and some have been redefined slightly. Additionally,
31    the sequencing of the SMBus transactions has been modified
32    to be more consistent with the sequencing recommended by
33    the manufacturer and observed through testing.  These
34    changes are reflected in this driver and can be identified
35    by comparing this driver to the i2c-ali15x3 driver.
36    For an overview of these chips see http://www.acerlabs.com
37
38    The SMB controller is part of the 7101 device, which is an
39    ACPI-compliant Power Management Unit (PMU).
40
41    The whole 7101 device has to be enabled for the SMB to work.
42    You can't just enable the SMB alone.
43    The SMB and the ACPI have separate I/O spaces.
44    We make sure that the SMB is enabled. We leave the ACPI alone.
45
46    This driver controls the SMB Host only.
47
48    This driver does not use interrupts.
49*/
50
51
52/* Note: we assume there can only be one ALI1535, with one SMBus interface */
53
54#include <linux/module.h>
55#include <linux/pci.h>
56#include <linux/kernel.h>
57#include <linux/stddef.h>
58#include <linux/delay.h>
59#include <linux/ioport.h>
60#include <linux/i2c.h>
61#include <linux/init.h>
62#include <linux/acpi.h>
63#include <linux/io.h>
64
65
66/* ALI1535 SMBus address offsets */
67#define SMBHSTSTS	(0 + ali1535_smba)
68#define SMBHSTTYP	(1 + ali1535_smba)
69#define SMBHSTPORT	(2 + ali1535_smba)
70#define SMBHSTCMD	(7 + ali1535_smba)
71#define SMBHSTADD	(3 + ali1535_smba)
72#define SMBHSTDAT0	(4 + ali1535_smba)
73#define SMBHSTDAT1	(5 + ali1535_smba)
74#define SMBBLKDAT	(6 + ali1535_smba)
75
76/* PCI Address Constants */
77#define SMBCOM		0x004
78#define SMBREV		0x008
79#define SMBCFG		0x0D1
80#define SMBBA		0x0E2
81#define SMBHSTCFG	0x0F0
82#define SMBCLK		0x0F2
83
84/* Other settings */
85#define MAX_TIMEOUT		500	/* times 1/100 sec */
86#define ALI1535_SMB_IOSIZE	32
87
88#define ALI1535_SMB_DEFAULTBASE	0x8040
89
90/* ALI1535 address lock bits */
91#define ALI1535_LOCK		0x06	/* dwe */
92
93/* ALI1535 command constants */
94#define ALI1535_QUICK		0x00
95#define ALI1535_BYTE		0x10
96#define ALI1535_BYTE_DATA	0x20
97#define ALI1535_WORD_DATA	0x30
98#define ALI1535_BLOCK_DATA	0x40
99#define ALI1535_I2C_READ	0x60
100
101#define	ALI1535_DEV10B_EN	0x80	/* Enable 10-bit addressing in	*/
102					/*  I2C read			*/
103#define	ALI1535_T_OUT		0x08	/* Time-out Command (write)	*/
104#define	ALI1535_A_HIGH_BIT9	0x08	/* Bit 9 of 10-bit address in	*/
105					/* Alert-Response-Address	*/
106					/* (read)			*/
107#define	ALI1535_KILL		0x04	/* Kill Command (write)		*/
108#define	ALI1535_A_HIGH_BIT8	0x04	/* Bit 8 of 10-bit address in	*/
109					/*  Alert-Response-Address	*/
110					/*  (read)			*/
111
112#define	ALI1535_D_HI_MASK	0x03	/* Mask for isolating bits 9-8	*/
113					/*  of 10-bit address in I2C	*/
114					/*  Read Command		*/
115
116/* ALI1535 status register bits */
117#define ALI1535_STS_IDLE	0x04
118#define ALI1535_STS_BUSY	0x08	/* host busy */
119#define ALI1535_STS_DONE	0x10	/* transaction complete */
120#define ALI1535_STS_DEV		0x20	/* device error */
121#define ALI1535_STS_BUSERR	0x40	/* bus error    */
122#define ALI1535_STS_FAIL	0x80	/* failed bus transaction */
123#define ALI1535_STS_ERR		0xE0	/* all the bad error bits */
124
125#define ALI1535_BLOCK_CLR	0x04	/* reset block data index */
126
127/* ALI1535 device address register bits */
128#define	ALI1535_RD_ADDR		0x01	/* Read/Write Bit in Device	*/
129					/*  Address field		*/
130					/*  -> Write = 0		*/
131					/*  -> Read  = 1		*/
132#define	ALI1535_SMBIO_EN	0x04	/* SMB I/O Space enable		*/
133
134static struct pci_driver ali1535_driver;
135static unsigned short ali1535_smba;
136
137/* Detect whether a ALI1535 can be found, and initialize it, where necessary.
138   Note the differences between kernels with the old PCI BIOS interface and
139   newer kernels with the real PCI interface. In compat.h some things are
140   defined to make the transition easier. */
141static int __devinit ali1535_setup(struct pci_dev *dev)
142{
143	int retval = -ENODEV;
144	unsigned char temp;
145
146	/* Check the following things:
147		- SMB I/O address is initialized
148		- Device is enabled
149		- We can use the addresses
150	*/
151
152	/* Determine the address of the SMBus area */
153	pci_read_config_word(dev, SMBBA, &ali1535_smba);
154	ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
155	if (ali1535_smba == 0) {
156		dev_warn(&dev->dev,
157			"ALI1535_smb region uninitialized - upgrade BIOS?\n");
158		goto exit;
159	}
160
161	retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
162				   ali1535_driver.name);
163	if (retval)
164		goto exit;
165
166	if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
167			    ali1535_driver.name)) {
168		dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
169			ali1535_smba);
170		goto exit;
171	}
172
173	/* check if whole device is enabled */
174	pci_read_config_byte(dev, SMBCFG, &temp);
175	if ((temp & ALI1535_SMBIO_EN) == 0) {
176		dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
177		goto exit_free;
178	}
179
180	/* Is SMB Host controller enabled? */
181	pci_read_config_byte(dev, SMBHSTCFG, &temp);
182	if ((temp & 1) == 0) {
183		dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
184		goto exit_free;
185	}
186
187	/* set SMB clock to 74KHz as recommended in data sheet */
188	pci_write_config_byte(dev, SMBCLK, 0x20);
189
190	/*
191	  The interrupt routing for SMB is set up in register 0x77 in the
192	  1533 ISA Bridge device, NOT in the 7101 device.
193	  Don't bother with finding the 1533 device and reading the register.
194	if ((....... & 0x0F) == 1)
195		dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
196	*/
197	pci_read_config_byte(dev, SMBREV, &temp);
198	dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
199	dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
200
201	retval = 0;
202exit:
203	return retval;
204
205exit_free:
206	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
207	return retval;
208}
209
210static int ali1535_transaction(struct i2c_adapter *adap)
211{
212	int temp;
213	int result = 0;
214	int timeout = 0;
215
216	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
217		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
218		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
219		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
220
221	/* get status */
222	temp = inb_p(SMBHSTSTS);
223
224	/* Make sure the SMBus host is ready to start transmitting */
225	/* Check the busy bit first */
226	if (temp & ALI1535_STS_BUSY) {
227		/* If the host controller is still busy, it may have timed out
228		 * in the previous transaction, resulting in a "SMBus Timeout"
229		 * printk.  I've tried the following to reset a stuck busy bit.
230		 *   1. Reset the controller with an KILL command. (this
231		 *      doesn't seem to clear the controller if an external
232		 *      device is hung)
233		 *   2. Reset the controller and the other SMBus devices with a
234		 *      T_OUT command. (this clears the host busy bit if an
235		 *      external device is hung, but it comes back upon a new
236		 *      access to a device)
237		 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
238		 *      case, nothing seems to work except power reset.
239		 */
240
241		/* Try resetting entire SMB bus, including other devices - This
242		 * may not work either - it clears the BUSY bit but then the
243		 * BUSY bit may come back on when you try and use the chip
244		 * again.  If that's the case you are stuck.
245		 */
246		dev_info(&adap->dev,
247			"Resetting entire SMB Bus to clear busy condition (%02x)\n",
248			temp);
249		outb_p(ALI1535_T_OUT, SMBHSTTYP);
250		temp = inb_p(SMBHSTSTS);
251	}
252
253	/* now check the error bits and the busy bit */
254	if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
255		/* do a clear-on-write */
256		outb_p(0xFF, SMBHSTSTS);
257		if ((temp = inb_p(SMBHSTSTS)) &
258		    (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
259			/* This is probably going to be correctable only by a
260			 * power reset as one of the bits now appears to be
261			 * stuck */
262			/* This may be a bus or device with electrical problems. */
263			dev_err(&adap->dev,
264				"SMBus reset failed! (0x%02x) - controller or "
265				"device on bus is probably hung\n", temp);
266			return -EBUSY;
267		}
268	} else {
269		/* check and clear done bit */
270		if (temp & ALI1535_STS_DONE) {
271			outb_p(temp, SMBHSTSTS);
272		}
273	}
274
275	/* start the transaction by writing anything to the start register */
276	outb_p(0xFF, SMBHSTPORT);
277
278	/* We will always wait for a fraction of a second! */
279	timeout = 0;
280	do {
281		msleep(1);
282		temp = inb_p(SMBHSTSTS);
283	} while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
284		 && (timeout++ < MAX_TIMEOUT));
285
286	/* If the SMBus is still busy, we give up */
287	if (timeout > MAX_TIMEOUT) {
288		result = -ETIMEDOUT;
289		dev_err(&adap->dev, "SMBus Timeout!\n");
290	}
291
292	if (temp & ALI1535_STS_FAIL) {
293		result = -EIO;
294		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
295	}
296
297	/* Unfortunately the ALI SMB controller maps "no response" and "bus
298	 * collision" into a single bit. No reponse is the usual case so don't
299	 * do a printk.  This means that bus collisions go unreported.
300	 */
301	if (temp & ALI1535_STS_BUSERR) {
302		result = -ENXIO;
303		dev_dbg(&adap->dev,
304			"Error: no response or bus collision ADD=%02x\n",
305			inb_p(SMBHSTADD));
306	}
307
308	/* haven't ever seen this */
309	if (temp & ALI1535_STS_DEV) {
310		result = -EIO;
311		dev_err(&adap->dev, "Error: device error\n");
312	}
313
314	/* check to see if the "command complete" indication is set */
315	if (!(temp & ALI1535_STS_DONE)) {
316		result = -ETIMEDOUT;
317		dev_err(&adap->dev, "Error: command never completed\n");
318	}
319
320	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
321		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
322		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
323		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
324
325	/* take consequent actions for error conditions */
326	if (!(temp & ALI1535_STS_DONE)) {
327		/* issue "kill" to reset host controller */
328		outb_p(ALI1535_KILL,SMBHSTTYP);
329		outb_p(0xFF,SMBHSTSTS);
330	} else if (temp & ALI1535_STS_ERR) {
331		/* issue "timeout" to reset all devices on bus */
332		outb_p(ALI1535_T_OUT,SMBHSTTYP);
333		outb_p(0xFF,SMBHSTSTS);
334	}
335
336	return result;
337}
338
339/* Return negative errno on error. */
340static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
341			  unsigned short flags, char read_write, u8 command,
342			  int size, union i2c_smbus_data *data)
343{
344	int i, len;
345	int temp;
346	int timeout;
347	s32 result = 0;
348
349	/* make sure SMBus is idle */
350	temp = inb_p(SMBHSTSTS);
351	for (timeout = 0;
352	     (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
353	     timeout++) {
354		msleep(1);
355		temp = inb_p(SMBHSTSTS);
356	}
357	if (timeout >= MAX_TIMEOUT)
358		dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
359
360	/* clear status register (clear-on-write) */
361	outb_p(0xFF, SMBHSTSTS);
362
363	switch (size) {
364	case I2C_SMBUS_QUICK:
365		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
366		       SMBHSTADD);
367		size = ALI1535_QUICK;
368		outb_p(size, SMBHSTTYP);	/* output command */
369		break;
370	case I2C_SMBUS_BYTE:
371		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
372		       SMBHSTADD);
373		size = ALI1535_BYTE;
374		outb_p(size, SMBHSTTYP);	/* output command */
375		if (read_write == I2C_SMBUS_WRITE)
376			outb_p(command, SMBHSTCMD);
377		break;
378	case I2C_SMBUS_BYTE_DATA:
379		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
380		       SMBHSTADD);
381		size = ALI1535_BYTE_DATA;
382		outb_p(size, SMBHSTTYP);	/* output command */
383		outb_p(command, SMBHSTCMD);
384		if (read_write == I2C_SMBUS_WRITE)
385			outb_p(data->byte, SMBHSTDAT0);
386		break;
387	case I2C_SMBUS_WORD_DATA:
388		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
389		       SMBHSTADD);
390		size = ALI1535_WORD_DATA;
391		outb_p(size, SMBHSTTYP);	/* output command */
392		outb_p(command, SMBHSTCMD);
393		if (read_write == I2C_SMBUS_WRITE) {
394			outb_p(data->word & 0xff, SMBHSTDAT0);
395			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
396		}
397		break;
398	case I2C_SMBUS_BLOCK_DATA:
399		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
400		       SMBHSTADD);
401		size = ALI1535_BLOCK_DATA;
402		outb_p(size, SMBHSTTYP);	/* output command */
403		outb_p(command, SMBHSTCMD);
404		if (read_write == I2C_SMBUS_WRITE) {
405			len = data->block[0];
406			if (len < 0) {
407				len = 0;
408				data->block[0] = len;
409			}
410			if (len > 32) {
411				len = 32;
412				data->block[0] = len;
413			}
414			outb_p(len, SMBHSTDAT0);
415			/* Reset SMBBLKDAT */
416			outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
417			for (i = 1; i <= len; i++)
418				outb_p(data->block[i], SMBBLKDAT);
419		}
420		break;
421	default:
422		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
423		result = -EOPNOTSUPP;
424		goto EXIT;
425	}
426
427	result = ali1535_transaction(adap);
428	if (result)
429		goto EXIT;
430
431	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
432		result = 0;
433		goto EXIT;
434	}
435
436	switch (size) {
437	case ALI1535_BYTE:	/* Result put in SMBHSTDAT0 */
438		data->byte = inb_p(SMBHSTDAT0);
439		break;
440	case ALI1535_BYTE_DATA:
441		data->byte = inb_p(SMBHSTDAT0);
442		break;
443	case ALI1535_WORD_DATA:
444		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
445		break;
446	case ALI1535_BLOCK_DATA:
447		len = inb_p(SMBHSTDAT0);
448		if (len > 32)
449			len = 32;
450		data->block[0] = len;
451		/* Reset SMBBLKDAT */
452		outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
453		for (i = 1; i <= data->block[0]; i++) {
454			data->block[i] = inb_p(SMBBLKDAT);
455			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
456				len, i, data->block[i]);
457		}
458		break;
459	}
460EXIT:
461	return result;
462}
463
464
465static u32 ali1535_func(struct i2c_adapter *adapter)
466{
467	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
468	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
469	    I2C_FUNC_SMBUS_BLOCK_DATA;
470}
471
472static const struct i2c_algorithm smbus_algorithm = {
473	.smbus_xfer	= ali1535_access,
474	.functionality	= ali1535_func,
475};
476
477static struct i2c_adapter ali1535_adapter = {
478	.owner		= THIS_MODULE,
479	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
480	.algo		= &smbus_algorithm,
481};
482
483static const struct pci_device_id ali1535_ids[] = {
484	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
485	{ },
486};
487
488MODULE_DEVICE_TABLE (pci, ali1535_ids);
489
490static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
491{
492	if (ali1535_setup(dev)) {
493		dev_warn(&dev->dev,
494			"ALI1535 not detected, module not inserted.\n");
495		return -ENODEV;
496	}
497
498	/* set up the sysfs linkage to our parent device */
499	ali1535_adapter.dev.parent = &dev->dev;
500
501	snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
502		"SMBus ALI1535 adapter at %04x", ali1535_smba);
503	return i2c_add_adapter(&ali1535_adapter);
504}
505
506static void __devexit ali1535_remove(struct pci_dev *dev)
507{
508	i2c_del_adapter(&ali1535_adapter);
509	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
510}
511
512static struct pci_driver ali1535_driver = {
513	.name		= "ali1535_smbus",
514	.id_table	= ali1535_ids,
515	.probe		= ali1535_probe,
516	.remove		= __devexit_p(ali1535_remove),
517};
518
519static int __init i2c_ali1535_init(void)
520{
521	return pci_register_driver(&ali1535_driver);
522}
523
524static void __exit i2c_ali1535_exit(void)
525{
526	pci_unregister_driver(&ali1535_driver);
527}
528
529MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
530	      "Philip Edelbrock <phil@netroedge.com>, "
531	      "Mark D. Studebaker <mdsxyz123@yahoo.com> "
532	      "and Dan Eaton <dan.eaton@rocketlogix.com>");
533MODULE_DESCRIPTION("ALI1535 SMBus driver");
534MODULE_LICENSE("GPL");
535
536module_init(i2c_ali1535_init);
537module_exit(i2c_ali1535_exit);
538