xref: /openbmc/linux/drivers/i2c/busses/i2c-ali1535.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
57 #include <linux/module.h>
58 #include <linux/pci.h>
59 #include <linux/kernel.h>
60 #include <linux/stddef.h>
61 #include <linux/sched.h>
62 #include <linux/delay.h>
63 #include <linux/ioport.h>
64 #include <linux/i2c.h>
65 #include <linux/init.h>
66 #include <asm/io.h>
67 #include <asm/semaphore.h>
68 
69 
70 /* ALI1535 SMBus address offsets */
71 #define SMBHSTSTS	(0 + ali1535_smba)
72 #define SMBHSTTYP	(1 + ali1535_smba)
73 #define SMBHSTPORT	(2 + ali1535_smba)
74 #define SMBHSTCMD	(7 + ali1535_smba)
75 #define SMBHSTADD	(3 + ali1535_smba)
76 #define SMBHSTDAT0	(4 + ali1535_smba)
77 #define SMBHSTDAT1	(5 + ali1535_smba)
78 #define SMBBLKDAT	(6 + ali1535_smba)
79 
80 /* PCI Address Constants */
81 #define SMBCOM		0x004
82 #define SMBREV		0x008
83 #define SMBCFG		0x0D1
84 #define SMBBA		0x0E2
85 #define SMBHSTCFG	0x0F0
86 #define SMBCLK		0x0F2
87 
88 /* Other settings */
89 #define MAX_TIMEOUT		500	/* times 1/100 sec */
90 #define ALI1535_SMB_IOSIZE	32
91 
92 #define ALI1535_SMB_DEFAULTBASE	0x8040
93 
94 /* ALI1535 address lock bits */
95 #define ALI1535_LOCK		0x06	/* dwe */
96 
97 /* ALI1535 command constants */
98 #define ALI1535_QUICK		0x00
99 #define ALI1535_BYTE		0x10
100 #define ALI1535_BYTE_DATA	0x20
101 #define ALI1535_WORD_DATA	0x30
102 #define ALI1535_BLOCK_DATA	0x40
103 #define ALI1535_I2C_READ	0x60
104 
105 #define	ALI1535_DEV10B_EN	0x80	/* Enable 10-bit addressing in	*/
106 					/*  I2C read			*/
107 #define	ALI1535_T_OUT		0x08	/* Time-out Command (write)	*/
108 #define	ALI1535_A_HIGH_BIT9	0x08	/* Bit 9 of 10-bit address in	*/
109 					/* Alert-Response-Address	*/
110 					/* (read)			*/
111 #define	ALI1535_KILL		0x04	/* Kill Command (write)		*/
112 #define	ALI1535_A_HIGH_BIT8	0x04	/* Bit 8 of 10-bit address in	*/
113 					/*  Alert-Response-Address	*/
114 					/*  (read)			*/
115 
116 #define	ALI1535_D_HI_MASK	0x03	/* Mask for isolating bits 9-8	*/
117 					/*  of 10-bit address in I2C	*/
118 					/*  Read Command		*/
119 
120 /* ALI1535 status register bits */
121 #define ALI1535_STS_IDLE	0x04
122 #define ALI1535_STS_BUSY	0x08	/* host busy */
123 #define ALI1535_STS_DONE	0x10	/* transaction complete */
124 #define ALI1535_STS_DEV		0x20	/* device error */
125 #define ALI1535_STS_BUSERR	0x40	/* bus error    */
126 #define ALI1535_STS_FAIL	0x80	/* failed bus transaction */
127 #define ALI1535_STS_ERR		0xE0	/* all the bad error bits */
128 
129 #define ALI1535_BLOCK_CLR	0x04	/* reset block data index */
130 
131 /* ALI1535 device address register bits */
132 #define	ALI1535_RD_ADDR		0x01	/* Read/Write Bit in Device	*/
133 					/*  Address field		*/
134 					/*  -> Write = 0		*/
135 					/*  -> Read  = 1		*/
136 #define	ALI1535_SMBIO_EN	0x04	/* SMB I/O Space enable		*/
137 
138 
139 static unsigned short ali1535_smba;
140 static DECLARE_MUTEX(i2c_ali1535_sem);
141 
142 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
143    Note the differences between kernels with the old PCI BIOS interface and
144    newer kernels with the real PCI interface. In compat.h some things are
145    defined to make the transition easier. */
146 static int ali1535_setup(struct pci_dev *dev)
147 {
148 	int retval = -ENODEV;
149 	unsigned char temp;
150 
151 	/* Check the following things:
152 		- SMB I/O address is initialized
153 		- Device is enabled
154 		- We can use the addresses
155 	*/
156 
157 	/* Determine the address of the SMBus area */
158 	pci_read_config_word(dev, SMBBA, &ali1535_smba);
159 	ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
160 	if (ali1535_smba == 0) {
161 		dev_warn(&dev->dev,
162 			"ALI1535_smb region uninitialized - upgrade BIOS?\n");
163 		goto exit;
164 	}
165 
166 	if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE, "ali1535-smb")) {
167 		dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
168 			ali1535_smba);
169 		goto exit;
170 	}
171 
172 	/* check if whole device is enabled */
173 	pci_read_config_byte(dev, SMBCFG, &temp);
174 	if ((temp & ALI1535_SMBIO_EN) == 0) {
175 		dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
176 		goto exit_free;
177 	}
178 
179 	/* Is SMB Host controller enabled? */
180 	pci_read_config_byte(dev, SMBHSTCFG, &temp);
181 	if ((temp & 1) == 0) {
182 		dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
183 		goto exit_free;
184 	}
185 
186 	/* set SMB clock to 74KHz as recommended in data sheet */
187 	pci_write_config_byte(dev, SMBCLK, 0x20);
188 
189 	/*
190 	  The interrupt routing for SMB is set up in register 0x77 in the
191 	  1533 ISA Bridge device, NOT in the 7101 device.
192 	  Don't bother with finding the 1533 device and reading the register.
193 	if ((....... & 0x0F) == 1)
194 		dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
195 	*/
196 	pci_read_config_byte(dev, SMBREV, &temp);
197 	dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
198 	dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
199 
200 	retval = 0;
201 exit:
202 	return retval;
203 
204 exit_free:
205 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
206 	return retval;
207 }
208 
209 static int ali1535_transaction(struct i2c_adapter *adap)
210 {
211 	int temp;
212 	int result = 0;
213 	int timeout = 0;
214 
215 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
216 		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
217 		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
218 		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
219 
220 	/* get status */
221 	temp = inb_p(SMBHSTSTS);
222 
223 	/* Make sure the SMBus host is ready to start transmitting */
224 	/* Check the busy bit first */
225 	if (temp & ALI1535_STS_BUSY) {
226 		/* If the host controller is still busy, it may have timed out
227 		 * in the previous transaction, resulting in a "SMBus Timeout"
228 		 * printk.  I've tried the following to reset a stuck busy bit.
229 		 *   1. Reset the controller with an KILL command. (this
230 		 *      doesn't seem to clear the controller if an external
231 		 *      device is hung)
232 		 *   2. Reset the controller and the other SMBus devices with a
233 		 *      T_OUT command. (this clears the host busy bit if an
234 		 *      external device is hung, but it comes back upon a new
235 		 *      access to a device)
236 		 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
237 		 *      case, nothing seems to work except power reset.
238 		 */
239 
240 		/* Try resetting entire SMB bus, including other devices - This
241 		 * may not work either - it clears the BUSY bit but then the
242 		 * BUSY bit may come back on when you try and use the chip
243 		 * again.  If that's the case you are stuck.
244 		 */
245 		dev_info(&adap->dev,
246 			"Resetting entire SMB Bus to clear busy condition (%02x)\n",
247 			temp);
248 		outb_p(ALI1535_T_OUT, SMBHSTTYP);
249 		temp = inb_p(SMBHSTSTS);
250 	}
251 
252 	/* now check the error bits and the busy bit */
253 	if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
254 		/* do a clear-on-write */
255 		outb_p(0xFF, SMBHSTSTS);
256 		if ((temp = inb_p(SMBHSTSTS)) &
257 		    (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
258 			/* This is probably going to be correctable only by a
259 			 * power reset as one of the bits now appears to be
260 			 * stuck */
261 			/* This may be a bus or device with electrical problems. */
262 			dev_err(&adap->dev,
263 				"SMBus reset failed! (0x%02x) - controller or "
264 				"device on bus is probably hung\n", temp);
265 			return -1;
266 		}
267 	} else {
268 		/* check and clear done bit */
269 		if (temp & ALI1535_STS_DONE) {
270 			outb_p(temp, SMBHSTSTS);
271 		}
272 	}
273 
274 	/* start the transaction by writing anything to the start register */
275 	outb_p(0xFF, SMBHSTPORT);
276 
277 	/* We will always wait for a fraction of a second! */
278 	timeout = 0;
279 	do {
280 		msleep(1);
281 		temp = inb_p(SMBHSTSTS);
282 	} while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
283 		 && (timeout++ < MAX_TIMEOUT));
284 
285 	/* If the SMBus is still busy, we give up */
286 	if (timeout >= MAX_TIMEOUT) {
287 		result = -1;
288 		dev_err(&adap->dev, "SMBus Timeout!\n");
289 	}
290 
291 	if (temp & ALI1535_STS_FAIL) {
292 		result = -1;
293 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
294 	}
295 
296 	/* Unfortunately the ALI SMB controller maps "no response" and "bus
297 	 * collision" into a single bit. No reponse is the usual case so don't
298 	 * do a printk.  This means that bus collisions go unreported.
299 	 */
300 	if (temp & ALI1535_STS_BUSERR) {
301 		result = -1;
302 		dev_dbg(&adap->dev,
303 			"Error: no response or bus collision ADD=%02x\n",
304 			inb_p(SMBHSTADD));
305 	}
306 
307 	/* haven't ever seen this */
308 	if (temp & ALI1535_STS_DEV) {
309 		result = -1;
310 		dev_err(&adap->dev, "Error: device error\n");
311 	}
312 
313 	/* check to see if the "command complete" indication is set */
314 	if (!(temp & ALI1535_STS_DONE)) {
315 		result = -1;
316 		dev_err(&adap->dev, "Error: command never completed\n");
317 	}
318 
319 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
320 		"CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
321 		inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
322 		inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
323 
324 	/* take consequent actions for error conditions */
325 	if (!(temp & ALI1535_STS_DONE)) {
326 		/* issue "kill" to reset host controller */
327 		outb_p(ALI1535_KILL,SMBHSTTYP);
328 		outb_p(0xFF,SMBHSTSTS);
329 	} else if (temp & ALI1535_STS_ERR) {
330 		/* issue "timeout" to reset all devices on bus */
331 		outb_p(ALI1535_T_OUT,SMBHSTTYP);
332 		outb_p(0xFF,SMBHSTSTS);
333 	}
334 
335 	return result;
336 }
337 
338 /* Return -1 on error. */
339 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
340 			  unsigned short flags, char read_write, u8 command,
341 			  int size, union i2c_smbus_data *data)
342 {
343 	int i, len;
344 	int temp;
345 	int timeout;
346 	s32 result = 0;
347 
348 	down(&i2c_ali1535_sem);
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_PROC_CALL:
365 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
366 		result = -1;
367 		goto EXIT;
368 	case I2C_SMBUS_QUICK:
369 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
370 		       SMBHSTADD);
371 		size = ALI1535_QUICK;
372 		outb_p(size, SMBHSTTYP);	/* output command */
373 		break;
374 	case I2C_SMBUS_BYTE:
375 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
376 		       SMBHSTADD);
377 		size = ALI1535_BYTE;
378 		outb_p(size, SMBHSTTYP);	/* output command */
379 		if (read_write == I2C_SMBUS_WRITE)
380 			outb_p(command, SMBHSTCMD);
381 		break;
382 	case I2C_SMBUS_BYTE_DATA:
383 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
384 		       SMBHSTADD);
385 		size = ALI1535_BYTE_DATA;
386 		outb_p(size, SMBHSTTYP);	/* output command */
387 		outb_p(command, SMBHSTCMD);
388 		if (read_write == I2C_SMBUS_WRITE)
389 			outb_p(data->byte, SMBHSTDAT0);
390 		break;
391 	case I2C_SMBUS_WORD_DATA:
392 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
393 		       SMBHSTADD);
394 		size = ALI1535_WORD_DATA;
395 		outb_p(size, SMBHSTTYP);	/* output command */
396 		outb_p(command, SMBHSTCMD);
397 		if (read_write == I2C_SMBUS_WRITE) {
398 			outb_p(data->word & 0xff, SMBHSTDAT0);
399 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
400 		}
401 		break;
402 	case I2C_SMBUS_BLOCK_DATA:
403 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
404 		       SMBHSTADD);
405 		size = ALI1535_BLOCK_DATA;
406 		outb_p(size, SMBHSTTYP);	/* output command */
407 		outb_p(command, SMBHSTCMD);
408 		if (read_write == I2C_SMBUS_WRITE) {
409 			len = data->block[0];
410 			if (len < 0) {
411 				len = 0;
412 				data->block[0] = len;
413 			}
414 			if (len > 32) {
415 				len = 32;
416 				data->block[0] = len;
417 			}
418 			outb_p(len, SMBHSTDAT0);
419 			/* Reset SMBBLKDAT */
420 			outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
421 			for (i = 1; i <= len; i++)
422 				outb_p(data->block[i], SMBBLKDAT);
423 		}
424 		break;
425 	}
426 
427 	if (ali1535_transaction(adap)) {
428 		/* Error in transaction */
429 		result = -1;
430 		goto EXIT;
431 	}
432 
433 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
434 		result = 0;
435 		goto EXIT;
436 	}
437 
438 	switch (size) {
439 	case ALI1535_BYTE:	/* Result put in SMBHSTDAT0 */
440 		data->byte = inb_p(SMBHSTDAT0);
441 		break;
442 	case ALI1535_BYTE_DATA:
443 		data->byte = inb_p(SMBHSTDAT0);
444 		break;
445 	case ALI1535_WORD_DATA:
446 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
447 		break;
448 	case ALI1535_BLOCK_DATA:
449 		len = inb_p(SMBHSTDAT0);
450 		if (len > 32)
451 			len = 32;
452 		data->block[0] = len;
453 		/* Reset SMBBLKDAT */
454 		outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
455 		for (i = 1; i <= data->block[0]; i++) {
456 			data->block[i] = inb_p(SMBBLKDAT);
457 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
458 				len, i, data->block[i]);
459 		}
460 		break;
461 	}
462 EXIT:
463 	up(&i2c_ali1535_sem);
464 	return result;
465 }
466 
467 
468 static u32 ali1535_func(struct i2c_adapter *adapter)
469 {
470 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
471 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
472 	    I2C_FUNC_SMBUS_BLOCK_DATA;
473 }
474 
475 static struct i2c_algorithm smbus_algorithm = {
476 	.name		= "Non-i2c SMBus adapter",
477 	.id		= I2C_ALGO_SMBUS,
478 	.smbus_xfer	= ali1535_access,
479 	.functionality	= ali1535_func,
480 };
481 
482 static struct i2c_adapter ali1535_adapter = {
483 	.owner		= THIS_MODULE,
484 	.class          = I2C_CLASS_HWMON,
485 	.algo		= &smbus_algorithm,
486 	.name		= "unset",
487 };
488 
489 static struct pci_device_id ali1535_ids[] = {
490 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
491 	{ },
492 };
493 
494 MODULE_DEVICE_TABLE (pci, ali1535_ids);
495 
496 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
497 {
498 	if (ali1535_setup(dev)) {
499 		dev_warn(&dev->dev,
500 			"ALI1535 not detected, module not inserted.\n");
501 		return -ENODEV;
502 	}
503 
504 	/* set up the driverfs linkage to our parent device */
505 	ali1535_adapter.dev.parent = &dev->dev;
506 
507 	snprintf(ali1535_adapter.name, I2C_NAME_SIZE,
508 		"SMBus ALI1535 adapter at %04x", ali1535_smba);
509 	return i2c_add_adapter(&ali1535_adapter);
510 }
511 
512 static void __devexit ali1535_remove(struct pci_dev *dev)
513 {
514 	i2c_del_adapter(&ali1535_adapter);
515 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
516 }
517 
518 static struct pci_driver ali1535_driver = {
519 	.name		= "ali1535_smbus",
520 	.id_table	= ali1535_ids,
521 	.probe		= ali1535_probe,
522 	.remove		= __devexit_p(ali1535_remove),
523 };
524 
525 static int __init i2c_ali1535_init(void)
526 {
527 	return pci_register_driver(&ali1535_driver);
528 }
529 
530 static void __exit i2c_ali1535_exit(void)
531 {
532 	pci_unregister_driver(&ali1535_driver);
533 }
534 
535 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
536 	      "Philip Edelbrock <phil@netroedge.com>, "
537 	      "Mark D. Studebaker <mdsxyz123@yahoo.com> "
538 	      "and Dan Eaton <dan.eaton@rocketlogix.com>");
539 MODULE_DESCRIPTION("ALI1535 SMBus driver");
540 MODULE_LICENSE("GPL");
541 
542 module_init(i2c_ali1535_init);
543 module_exit(i2c_ali1535_exit);
544