xref: /linux/drivers/i2c/busses/i2c-ali1535.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2     i2c-ali1535.c - Part of lm_sensors, Linux kernel modules for hardware
3                     monitoring
4     Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
5                         Philip Edelbrock <phil@netroedge.com>,
6                         Mark D. Studebaker <mdsxyz123@yahoo.com>,
7                         Dan Eaton <dan.eaton@rocketlogix.com> and
8                         Stephen Rousset<stephen.rousset@rocketlogix.com>
9 
10     This program is free software; you can redistribute it and/or modify
11     it under the terms of the GNU General Public License as published by
12     the Free Software Foundation; either version 2 of the License, or
13     (at your option) any later version.
14 
15     This program is distributed in the hope that it will be useful,
16     but WITHOUT ANY WARRANTY; without even the implied warranty of
17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18     GNU General Public License for more details.
19 
20     You should have received a copy of the GNU General Public License
21     along with this program; if not, write to the Free Software
22     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */
24 
25 /*
26     This is the driver for the SMB Host controller on
27     Acer Labs Inc. (ALI) M1535 South Bridge.
28 
29     The M1535 is a South bridge for portable systems.
30     It is very similar to the M15x3 South bridges also produced
31     by Acer Labs Inc.  Some of the registers within the part
32     have moved and some have been redefined slightly. Additionally,
33     the sequencing of the SMBus transactions has been modified
34     to be more consistent with the sequencing recommended by
35     the manufacturer and observed through testing.  These
36     changes are reflected in this driver and can be identified
37     by comparing this driver to the i2c-ali15x3 driver.
38     For an overview of these chips see http://www.acerlabs.com
39 
40     The SMB controller is part of the 7101 device, which is an
41     ACPI-compliant Power Management Unit (PMU).
42 
43     The whole 7101 device has to be enabled for the SMB to work.
44     You can't just enable the SMB alone.
45     The SMB and the ACPI have separate I/O spaces.
46     We make sure that the SMB is enabled. We leave the ACPI alone.
47 
48     This driver controls the SMB Host only.
49 
50     This driver does not use interrupts.
51 */
52 
53 
54 /* Note: we assume there can only be one ALI1535, with one SMBus interface */
55 
56 #include <linux/module.h>
57 #include <linux/pci.h>
58 #include <linux/kernel.h>
59 #include <linux/stddef.h>
60 #include <linux/sched.h>
61 #include <linux/delay.h>
62 #include <linux/ioport.h>
63 #include <linux/i2c.h>
64 #include <linux/init.h>
65 #include <asm/io.h>
66 
67 
68 /* ALI1535 SMBus address offsets */
69 #define SMBHSTSTS	(0 + ali1535_smba)
70 #define SMBHSTTYP	(1 + ali1535_smba)
71 #define SMBHSTPORT	(2 + ali1535_smba)
72 #define SMBHSTCMD	(7 + ali1535_smba)
73 #define SMBHSTADD	(3 + ali1535_smba)
74 #define SMBHSTDAT0	(4 + ali1535_smba)
75 #define SMBHSTDAT1	(5 + ali1535_smba)
76 #define SMBBLKDAT	(6 + ali1535_smba)
77 
78 /* PCI Address Constants */
79 #define SMBCOM		0x004
80 #define SMBREV		0x008
81 #define SMBCFG		0x0D1
82 #define SMBBA		0x0E2
83 #define SMBHSTCFG	0x0F0
84 #define SMBCLK		0x0F2
85 
86 /* Other settings */
87 #define MAX_TIMEOUT		500	/* times 1/100 sec */
88 #define ALI1535_SMB_IOSIZE	32
89 
90 #define ALI1535_SMB_DEFAULTBASE	0x8040
91 
92 /* ALI1535 address lock bits */
93 #define ALI1535_LOCK		0x06	/* dwe */
94 
95 /* ALI1535 command constants */
96 #define ALI1535_QUICK		0x00
97 #define ALI1535_BYTE		0x10
98 #define ALI1535_BYTE_DATA	0x20
99 #define ALI1535_WORD_DATA	0x30
100 #define ALI1535_BLOCK_DATA	0x40
101 #define ALI1535_I2C_READ	0x60
102 
103 #define	ALI1535_DEV10B_EN	0x80	/* Enable 10-bit addressing in	*/
104 					/*  I2C read			*/
105 #define	ALI1535_T_OUT		0x08	/* Time-out Command (write)	*/
106 #define	ALI1535_A_HIGH_BIT9	0x08	/* Bit 9 of 10-bit address in	*/
107 					/* Alert-Response-Address	*/
108 					/* (read)			*/
109 #define	ALI1535_KILL		0x04	/* Kill Command (write)		*/
110 #define	ALI1535_A_HIGH_BIT8	0x04	/* Bit 8 of 10-bit address in	*/
111 					/*  Alert-Response-Address	*/
112 					/*  (read)			*/
113 
114 #define	ALI1535_D_HI_MASK	0x03	/* Mask for isolating bits 9-8	*/
115 					/*  of 10-bit address in I2C	*/
116 					/*  Read Command		*/
117 
118 /* ALI1535 status register bits */
119 #define ALI1535_STS_IDLE	0x04
120 #define ALI1535_STS_BUSY	0x08	/* host busy */
121 #define ALI1535_STS_DONE	0x10	/* transaction complete */
122 #define ALI1535_STS_DEV		0x20	/* device error */
123 #define ALI1535_STS_BUSERR	0x40	/* bus error    */
124 #define ALI1535_STS_FAIL	0x80	/* failed bus transaction */
125 #define ALI1535_STS_ERR		0xE0	/* all the bad error bits */
126 
127 #define ALI1535_BLOCK_CLR	0x04	/* reset block data index */
128 
129 /* ALI1535 device address register bits */
130 #define	ALI1535_RD_ADDR		0x01	/* Read/Write Bit in Device	*/
131 					/*  Address field		*/
132 					/*  -> Write = 0		*/
133 					/*  -> Read  = 1		*/
134 #define	ALI1535_SMBIO_EN	0x04	/* SMB I/O Space enable		*/
135 
136 static struct pci_driver ali1535_driver;
137 static unsigned short ali1535_smba;
138 
139 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
140    Note the differences between kernels with the old PCI BIOS interface and
141    newer kernels with the real PCI interface. In compat.h some things are
142    defined to make the transition easier. */
143 static int ali1535_setup(struct pci_dev *dev)
144 {
145 	int retval = -ENODEV;
146 	unsigned char temp;
147 
148 	/* Check the following things:
149 		- SMB I/O address is initialized
150 		- Device is enabled
151 		- We can use the addresses
152 	*/
153 
154 	/* Determine the address of the SMBus area */
155 	pci_read_config_word(dev, SMBBA, &ali1535_smba);
156 	ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
157 	if (ali1535_smba == 0) {
158 		dev_warn(&dev->dev,
159 			"ALI1535_smb region uninitialized - upgrade BIOS?\n");
160 		goto exit;
161 	}
162 
163 	if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
164 			    ali1535_driver.name)) {
165 		dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
166 			ali1535_smba);
167 		goto exit;
168 	}
169 
170 	/* check if whole device is enabled */
171 	pci_read_config_byte(dev, SMBCFG, &temp);
172 	if ((temp & ALI1535_SMBIO_EN) == 0) {
173 		dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
174 		goto exit_free;
175 	}
176 
177 	/* Is SMB Host controller enabled? */
178 	pci_read_config_byte(dev, SMBHSTCFG, &temp);
179 	if ((temp & 1) == 0) {
180 		dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
181 		goto exit_free;
182 	}
183 
184 	/* set SMB clock to 74KHz as recommended in data sheet */
185 	pci_write_config_byte(dev, SMBCLK, 0x20);
186 
187 	/*
188 	  The interrupt routing for SMB is set up in register 0x77 in the
189 	  1533 ISA Bridge device, NOT in the 7101 device.
190 	  Don't bother with finding the 1533 device and reading the register.
191 	if ((....... & 0x0F) == 1)
192 		dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
193 	*/
194 	pci_read_config_byte(dev, SMBREV, &temp);
195 	dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
196 	dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
197 
198 	retval = 0;
199 exit:
200 	return retval;
201 
202 exit_free:
203 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
204 	return retval;
205 }
206 
207 static int ali1535_transaction(struct i2c_adapter *adap)
208 {
209 	int temp;
210 	int result = 0;
211 	int timeout = 0;
212 
213 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
214 		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
215 		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
216 		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
217 
218 	/* get status */
219 	temp = inb_p(SMBHSTSTS);
220 
221 	/* Make sure the SMBus host is ready to start transmitting */
222 	/* Check the busy bit first */
223 	if (temp & ALI1535_STS_BUSY) {
224 		/* If the host controller is still busy, it may have timed out
225 		 * in the previous transaction, resulting in a "SMBus Timeout"
226 		 * printk.  I've tried the following to reset a stuck busy bit.
227 		 *   1. Reset the controller with an KILL command. (this
228 		 *      doesn't seem to clear the controller if an external
229 		 *      device is hung)
230 		 *   2. Reset the controller and the other SMBus devices with a
231 		 *      T_OUT command. (this clears the host busy bit if an
232 		 *      external device is hung, but it comes back upon a new
233 		 *      access to a device)
234 		 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
235 		 *      case, nothing seems to work except power reset.
236 		 */
237 
238 		/* Try resetting entire SMB bus, including other devices - This
239 		 * may not work either - it clears the BUSY bit but then the
240 		 * BUSY bit may come back on when you try and use the chip
241 		 * again.  If that's the case you are stuck.
242 		 */
243 		dev_info(&adap->dev,
244 			"Resetting entire SMB Bus to clear busy condition (%02x)\n",
245 			temp);
246 		outb_p(ALI1535_T_OUT, SMBHSTTYP);
247 		temp = inb_p(SMBHSTSTS);
248 	}
249 
250 	/* now check the error bits and the busy bit */
251 	if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
252 		/* do a clear-on-write */
253 		outb_p(0xFF, SMBHSTSTS);
254 		if ((temp = inb_p(SMBHSTSTS)) &
255 		    (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
256 			/* This is probably going to be correctable only by a
257 			 * power reset as one of the bits now appears to be
258 			 * stuck */
259 			/* This may be a bus or device with electrical problems. */
260 			dev_err(&adap->dev,
261 				"SMBus reset failed! (0x%02x) - controller or "
262 				"device on bus is probably hung\n", temp);
263 			return -1;
264 		}
265 	} else {
266 		/* check and clear done bit */
267 		if (temp & ALI1535_STS_DONE) {
268 			outb_p(temp, SMBHSTSTS);
269 		}
270 	}
271 
272 	/* start the transaction by writing anything to the start register */
273 	outb_p(0xFF, SMBHSTPORT);
274 
275 	/* We will always wait for a fraction of a second! */
276 	timeout = 0;
277 	do {
278 		msleep(1);
279 		temp = inb_p(SMBHSTSTS);
280 	} while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
281 		 && (timeout++ < MAX_TIMEOUT));
282 
283 	/* If the SMBus is still busy, we give up */
284 	if (timeout >= MAX_TIMEOUT) {
285 		result = -1;
286 		dev_err(&adap->dev, "SMBus Timeout!\n");
287 	}
288 
289 	if (temp & ALI1535_STS_FAIL) {
290 		result = -1;
291 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
292 	}
293 
294 	/* Unfortunately the ALI SMB controller maps "no response" and "bus
295 	 * collision" into a single bit. No reponse is the usual case so don't
296 	 * do a printk.  This means that bus collisions go unreported.
297 	 */
298 	if (temp & ALI1535_STS_BUSERR) {
299 		result = -1;
300 		dev_dbg(&adap->dev,
301 			"Error: no response or bus collision ADD=%02x\n",
302 			inb_p(SMBHSTADD));
303 	}
304 
305 	/* haven't ever seen this */
306 	if (temp & ALI1535_STS_DEV) {
307 		result = -1;
308 		dev_err(&adap->dev, "Error: device error\n");
309 	}
310 
311 	/* check to see if the "command complete" indication is set */
312 	if (!(temp & ALI1535_STS_DONE)) {
313 		result = -1;
314 		dev_err(&adap->dev, "Error: command never completed\n");
315 	}
316 
317 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
318 		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
319 		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
320 		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
321 
322 	/* take consequent actions for error conditions */
323 	if (!(temp & ALI1535_STS_DONE)) {
324 		/* issue "kill" to reset host controller */
325 		outb_p(ALI1535_KILL,SMBHSTTYP);
326 		outb_p(0xFF,SMBHSTSTS);
327 	} else if (temp & ALI1535_STS_ERR) {
328 		/* issue "timeout" to reset all devices on bus */
329 		outb_p(ALI1535_T_OUT,SMBHSTTYP);
330 		outb_p(0xFF,SMBHSTSTS);
331 	}
332 
333 	return result;
334 }
335 
336 /* Return -1 on error. */
337 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
338 			  unsigned short flags, char read_write, u8 command,
339 			  int size, union i2c_smbus_data *data)
340 {
341 	int i, len;
342 	int temp;
343 	int timeout;
344 	s32 result = 0;
345 
346 	/* make sure SMBus is idle */
347 	temp = inb_p(SMBHSTSTS);
348 	for (timeout = 0;
349 	     (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
350 	     timeout++) {
351 		msleep(1);
352 		temp = inb_p(SMBHSTSTS);
353 	}
354 	if (timeout >= MAX_TIMEOUT)
355 		dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
356 
357 	/* clear status register (clear-on-write) */
358 	outb_p(0xFF, SMBHSTSTS);
359 
360 	switch (size) {
361 	case I2C_SMBUS_PROC_CALL:
362 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
363 		result = -1;
364 		goto EXIT;
365 	case I2C_SMBUS_QUICK:
366 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
367 		       SMBHSTADD);
368 		size = ALI1535_QUICK;
369 		outb_p(size, SMBHSTTYP);	/* output command */
370 		break;
371 	case I2C_SMBUS_BYTE:
372 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
373 		       SMBHSTADD);
374 		size = ALI1535_BYTE;
375 		outb_p(size, SMBHSTTYP);	/* output command */
376 		if (read_write == I2C_SMBUS_WRITE)
377 			outb_p(command, SMBHSTCMD);
378 		break;
379 	case I2C_SMBUS_BYTE_DATA:
380 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
381 		       SMBHSTADD);
382 		size = ALI1535_BYTE_DATA;
383 		outb_p(size, SMBHSTTYP);	/* output command */
384 		outb_p(command, SMBHSTCMD);
385 		if (read_write == I2C_SMBUS_WRITE)
386 			outb_p(data->byte, SMBHSTDAT0);
387 		break;
388 	case I2C_SMBUS_WORD_DATA:
389 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
390 		       SMBHSTADD);
391 		size = ALI1535_WORD_DATA;
392 		outb_p(size, SMBHSTTYP);	/* output command */
393 		outb_p(command, SMBHSTCMD);
394 		if (read_write == I2C_SMBUS_WRITE) {
395 			outb_p(data->word & 0xff, SMBHSTDAT0);
396 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
397 		}
398 		break;
399 	case I2C_SMBUS_BLOCK_DATA:
400 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
401 		       SMBHSTADD);
402 		size = ALI1535_BLOCK_DATA;
403 		outb_p(size, SMBHSTTYP);	/* output command */
404 		outb_p(command, SMBHSTCMD);
405 		if (read_write == I2C_SMBUS_WRITE) {
406 			len = data->block[0];
407 			if (len < 0) {
408 				len = 0;
409 				data->block[0] = len;
410 			}
411 			if (len > 32) {
412 				len = 32;
413 				data->block[0] = len;
414 			}
415 			outb_p(len, SMBHSTDAT0);
416 			/* Reset SMBBLKDAT */
417 			outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
418 			for (i = 1; i <= len; i++)
419 				outb_p(data->block[i], SMBBLKDAT);
420 		}
421 		break;
422 	}
423 
424 	if (ali1535_transaction(adap)) {
425 		/* Error in transaction */
426 		result = -1;
427 		goto EXIT;
428 	}
429 
430 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
431 		result = 0;
432 		goto EXIT;
433 	}
434 
435 	switch (size) {
436 	case ALI1535_BYTE:	/* Result put in SMBHSTDAT0 */
437 		data->byte = inb_p(SMBHSTDAT0);
438 		break;
439 	case ALI1535_BYTE_DATA:
440 		data->byte = inb_p(SMBHSTDAT0);
441 		break;
442 	case ALI1535_WORD_DATA:
443 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
444 		break;
445 	case ALI1535_BLOCK_DATA:
446 		len = inb_p(SMBHSTDAT0);
447 		if (len > 32)
448 			len = 32;
449 		data->block[0] = len;
450 		/* Reset SMBBLKDAT */
451 		outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
452 		for (i = 1; i <= data->block[0]; i++) {
453 			data->block[i] = inb_p(SMBBLKDAT);
454 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
455 				len, i, data->block[i]);
456 		}
457 		break;
458 	}
459 EXIT:
460 	return result;
461 }
462 
463 
464 static u32 ali1535_func(struct i2c_adapter *adapter)
465 {
466 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
467 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
468 	    I2C_FUNC_SMBUS_BLOCK_DATA;
469 }
470 
471 static struct i2c_algorithm smbus_algorithm = {
472 	.smbus_xfer	= ali1535_access,
473 	.functionality	= ali1535_func,
474 };
475 
476 static struct i2c_adapter ali1535_adapter = {
477 	.owner		= THIS_MODULE,
478 	.class          = I2C_CLASS_HWMON,
479 	.algo		= &smbus_algorithm,
480 };
481 
482 static struct pci_device_id ali1535_ids[] = {
483 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
484 	{ },
485 };
486 
487 MODULE_DEVICE_TABLE (pci, ali1535_ids);
488 
489 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
490 {
491 	if (ali1535_setup(dev)) {
492 		dev_warn(&dev->dev,
493 			"ALI1535 not detected, module not inserted.\n");
494 		return -ENODEV;
495 	}
496 
497 	/* set up the driverfs linkage to our parent device */
498 	ali1535_adapter.dev.parent = &dev->dev;
499 
500 	snprintf(ali1535_adapter.name, I2C_NAME_SIZE,
501 		"SMBus ALI1535 adapter at %04x", ali1535_smba);
502 	return i2c_add_adapter(&ali1535_adapter);
503 }
504 
505 static void __devexit ali1535_remove(struct pci_dev *dev)
506 {
507 	i2c_del_adapter(&ali1535_adapter);
508 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
509 }
510 
511 static struct pci_driver ali1535_driver = {
512 	.name		= "ali1535_smbus",
513 	.id_table	= ali1535_ids,
514 	.probe		= ali1535_probe,
515 	.remove		= __devexit_p(ali1535_remove),
516 };
517 
518 static int __init i2c_ali1535_init(void)
519 {
520 	return pci_register_driver(&ali1535_driver);
521 }
522 
523 static void __exit i2c_ali1535_exit(void)
524 {
525 	pci_unregister_driver(&ali1535_driver);
526 }
527 
528 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
529 	      "Philip Edelbrock <phil@netroedge.com>, "
530 	      "Mark D. Studebaker <mdsxyz123@yahoo.com> "
531 	      "and Dan Eaton <dan.eaton@rocketlogix.com>");
532 MODULE_DESCRIPTION("ALI1535 SMBus driver");
533 MODULE_LICENSE("GPL");
534 
535 module_init(i2c_ali1535_init);
536 module_exit(i2c_ali1535_exit);
537