xref: /openbmc/linux/drivers/i2c/busses/i2c-ali15x3.c (revision 275876e2)
1 /*
2     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
3     Philip Edelbrock <phil@netroedge.com> and
4     Mark D. Studebaker <mdsxyz123@yahoo.com>
5 
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10 
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15 
16     You should have received a copy of the GNU General Public License
17     along with this program; if not, write to the Free Software
18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 
21 /*
22     This is the driver for the SMB Host controller on
23     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
24 
25     The M1543C is a South bridge for desktop systems.
26     The M1533 is a South bridge for portable systems.
27     They are part of the following ALI chipsets:
28        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
29        with AGP and 100MHz CPU Front Side bus
30        "Aladdin V": Includes the M1541 Socket 7 North bridge
31        with AGP and 100MHz CPU Front Side bus
32        "Aladdin IV": Includes the M1541 Socket 7 North bridge
33        with host bus up to 83.3 MHz.
34     For an overview of these chips see http://www.acerlabs.com
35 
36     The M1533/M1543C devices appear as FOUR separate devices
37     on the PCI bus. An output of lspci will show something similar
38     to the following:
39 
40 	00:02.0 USB Controller: Acer Laboratories Inc. M5237
41 	00:03.0 Bridge: Acer Laboratories Inc. M7101
42 	00:07.0 ISA bridge: Acer Laboratories Inc. M1533
43 	00:0f.0 IDE interface: Acer Laboratories Inc. M5229
44 
45     The SMB controller is part of the 7101 device, which is an
46     ACPI-compliant Power Management Unit (PMU).
47 
48     The whole 7101 device has to be enabled for the SMB to work.
49     You can't just enable the SMB alone.
50     The SMB and the ACPI have separate I/O spaces.
51     We make sure that the SMB is enabled. We leave the ACPI alone.
52 
53     This driver controls the SMB Host only.
54     The SMB Slave controller on the M15X3 is not enabled.
55 
56     This driver does not use interrupts.
57 */
58 
59 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
60 
61 #include <linux/module.h>
62 #include <linux/pci.h>
63 #include <linux/kernel.h>
64 #include <linux/stddef.h>
65 #include <linux/ioport.h>
66 #include <linux/delay.h>
67 #include <linux/i2c.h>
68 #include <linux/acpi.h>
69 #include <linux/io.h>
70 
71 /* ALI15X3 SMBus address offsets */
72 #define SMBHSTSTS	(0 + ali15x3_smba)
73 #define SMBHSTCNT	(1 + ali15x3_smba)
74 #define SMBHSTSTART	(2 + ali15x3_smba)
75 #define SMBHSTCMD	(7 + ali15x3_smba)
76 #define SMBHSTADD	(3 + ali15x3_smba)
77 #define SMBHSTDAT0	(4 + ali15x3_smba)
78 #define SMBHSTDAT1	(5 + ali15x3_smba)
79 #define SMBBLKDAT	(6 + ali15x3_smba)
80 
81 /* PCI Address Constants */
82 #define SMBCOM		0x004
83 #define SMBBA		0x014
84 #define SMBATPC		0x05B	/* used to unlock xxxBA registers */
85 #define SMBHSTCFG	0x0E0
86 #define SMBSLVC		0x0E1
87 #define SMBCLK		0x0E2
88 #define SMBREV		0x008
89 
90 /* Other settings */
91 #define MAX_TIMEOUT		200	/* times 1/100 sec */
92 #define ALI15X3_SMB_IOSIZE	32
93 
94 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
95    We don't use these here. If the bases aren't set to some value we
96    tell user to upgrade BIOS and we fail.
97 */
98 #define ALI15X3_SMB_DEFAULTBASE	0xE800
99 
100 /* ALI15X3 address lock bits */
101 #define ALI15X3_LOCK		0x06
102 
103 /* ALI15X3 command constants */
104 #define ALI15X3_ABORT		0x02
105 #define ALI15X3_T_OUT		0x04
106 #define ALI15X3_QUICK		0x00
107 #define ALI15X3_BYTE		0x10
108 #define ALI15X3_BYTE_DATA	0x20
109 #define ALI15X3_WORD_DATA	0x30
110 #define ALI15X3_BLOCK_DATA	0x40
111 #define ALI15X3_BLOCK_CLR	0x80
112 
113 /* ALI15X3 status register bits */
114 #define ALI15X3_STS_IDLE	0x04
115 #define ALI15X3_STS_BUSY	0x08
116 #define ALI15X3_STS_DONE	0x10
117 #define ALI15X3_STS_DEV		0x20	/* device error */
118 #define ALI15X3_STS_COLL	0x40	/* collision or no response */
119 #define ALI15X3_STS_TERM	0x80	/* terminated by abort */
120 #define ALI15X3_STS_ERR		0xE0	/* all the bad error bits */
121 
122 
123 /* If force_addr is set to anything different from 0, we forcibly enable
124    the device at the given address. */
125 static u16 force_addr;
126 module_param(force_addr, ushort, 0);
127 MODULE_PARM_DESC(force_addr,
128 		 "Initialize the base address of the i2c controller");
129 
130 static struct pci_driver ali15x3_driver;
131 static unsigned short ali15x3_smba;
132 
133 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
134 {
135 	u16 a;
136 	unsigned char temp;
137 
138 	/* Check the following things:
139 		- SMB I/O address is initialized
140 		- Device is enabled
141 		- We can use the addresses
142 	*/
143 
144 	/* Unlock the register.
145 	   The data sheet says that the address registers are read-only
146 	   if the lock bits are 1, but in fact the address registers
147 	   are zero unless you clear the lock bits.
148 	*/
149 	pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
150 	if (temp & ALI15X3_LOCK) {
151 		temp &= ~ALI15X3_LOCK;
152 		pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
153 	}
154 
155 	/* Determine the address of the SMBus area */
156 	pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
157 	ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
158 	if (ali15x3_smba == 0 && force_addr == 0) {
159 		dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
160 			"- upgrade BIOS or use force_addr=0xaddr\n");
161 		return -ENODEV;
162 	}
163 
164 	if(force_addr)
165 		ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
166 
167 	if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
168 			      ali15x3_driver.name))
169 		return -EBUSY;
170 
171 	if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
172 			    ali15x3_driver.name)) {
173 		dev_err(&ALI15X3_dev->dev,
174 			"ALI15X3_smb region 0x%x already in use!\n",
175 			ali15x3_smba);
176 		return -ENODEV;
177 	}
178 
179 	if(force_addr) {
180 		dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
181 			ali15x3_smba);
182 		if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
183 								SMBBA,
184 								ali15x3_smba))
185 			goto error;
186 		if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
187 								SMBBA, &a))
188 			goto error;
189 		if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
190 			/* make sure it works */
191 			dev_err(&ALI15X3_dev->dev,
192 				"force address failed - not supported?\n");
193 			goto error;
194 		}
195 	}
196 	/* check if whole device is enabled */
197 	pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
198 	if ((temp & 1) == 0) {
199 		dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
200 		pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
201 	}
202 
203 	/* Is SMB Host controller enabled? */
204 	pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
205 	if ((temp & 1) == 0) {
206 		dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
207 		pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
208 	}
209 
210 	/* set SMB clock to 74KHz as recommended in data sheet */
211 	pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
212 
213 	/*
214 	  The interrupt routing for SMB is set up in register 0x77 in the
215 	  1533 ISA Bridge device, NOT in the 7101 device.
216 	  Don't bother with finding the 1533 device and reading the register.
217 	if ((....... & 0x0F) == 1)
218 		dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
219 	*/
220 	pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
221 	dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
222 	dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
223 
224 	return 0;
225 error:
226 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
227 	return -ENODEV;
228 }
229 
230 /* Another internally used function */
231 static int ali15x3_transaction(struct i2c_adapter *adap)
232 {
233 	int temp;
234 	int result = 0;
235 	int timeout = 0;
236 
237 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
238 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
239 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
240 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
241 
242 	/* get status */
243 	temp = inb_p(SMBHSTSTS);
244 
245 	/* Make sure the SMBus host is ready to start transmitting */
246 	/* Check the busy bit first */
247 	if (temp & ALI15X3_STS_BUSY) {
248 	/*
249 	   If the host controller is still busy, it may have timed out in the
250 	   previous transaction, resulting in a "SMBus Timeout" Dev.
251 	   I've tried the following to reset a stuck busy bit.
252 		1. Reset the controller with an ABORT command.
253 		   (this doesn't seem to clear the controller if an external
254 		   device is hung)
255 		2. Reset the controller and the other SMBus devices with a
256 		   T_OUT command.  (this clears the host busy bit if an
257 		   external device is hung, but it comes back upon a new access
258 		   to a device)
259 		3. Disable and reenable the controller in SMBHSTCFG
260 	   Worst case, nothing seems to work except power reset.
261 	*/
262 	/* Abort - reset the host controller */
263 	/*
264 	   Try resetting entire SMB bus, including other devices -
265 	   This may not work either - it clears the BUSY bit but
266 	   then the BUSY bit may come back on when you try and use the chip again.
267 	   If that's the case you are stuck.
268 	*/
269 		dev_info(&adap->dev, "Resetting entire SMB Bus to "
270 			"clear busy condition (%02x)\n", temp);
271 		outb_p(ALI15X3_T_OUT, SMBHSTCNT);
272 		temp = inb_p(SMBHSTSTS);
273 	}
274 
275 	/* now check the error bits and the busy bit */
276 	if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
277 		/* do a clear-on-write */
278 		outb_p(0xFF, SMBHSTSTS);
279 		if ((temp = inb_p(SMBHSTSTS)) &
280 		    (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
281 			/* this is probably going to be correctable only by a power reset
282 			   as one of the bits now appears to be stuck */
283 			/* This may be a bus or device with electrical problems. */
284 			dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
285 				"controller or device on bus is probably hung\n",
286 				temp);
287 			return -EBUSY;
288 		}
289 	} else {
290 		/* check and clear done bit */
291 		if (temp & ALI15X3_STS_DONE) {
292 			outb_p(temp, SMBHSTSTS);
293 		}
294 	}
295 
296 	/* start the transaction by writing anything to the start register */
297 	outb_p(0xFF, SMBHSTSTART);
298 
299 	/* We will always wait for a fraction of a second! */
300 	timeout = 0;
301 	do {
302 		msleep(1);
303 		temp = inb_p(SMBHSTSTS);
304 	} while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
305 		 && (timeout++ < MAX_TIMEOUT));
306 
307 	/* If the SMBus is still busy, we give up */
308 	if (timeout > MAX_TIMEOUT) {
309 		result = -ETIMEDOUT;
310 		dev_err(&adap->dev, "SMBus Timeout!\n");
311 	}
312 
313 	if (temp & ALI15X3_STS_TERM) {
314 		result = -EIO;
315 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
316 	}
317 
318 	/*
319 	  Unfortunately the ALI SMB controller maps "no response" and "bus
320 	  collision" into a single bit. No response is the usual case so don't
321 	  do a printk.
322 	  This means that bus collisions go unreported.
323 	*/
324 	if (temp & ALI15X3_STS_COLL) {
325 		result = -ENXIO;
326 		dev_dbg(&adap->dev,
327 			"Error: no response or bus collision ADD=%02x\n",
328 			inb_p(SMBHSTADD));
329 	}
330 
331 	/* haven't ever seen this */
332 	if (temp & ALI15X3_STS_DEV) {
333 		result = -EIO;
334 		dev_err(&adap->dev, "Error: device error\n");
335 	}
336 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
337 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
338 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
339 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
340 	return result;
341 }
342 
343 /* Return negative errno on error. */
344 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
345 		   unsigned short flags, char read_write, u8 command,
346 		   int size, union i2c_smbus_data * data)
347 {
348 	int i, len;
349 	int temp;
350 	int timeout;
351 
352 	/* clear all the bits (clear-on-write) */
353 	outb_p(0xFF, SMBHSTSTS);
354 	/* make sure SMBus is idle */
355 	temp = inb_p(SMBHSTSTS);
356 	for (timeout = 0;
357 	     (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
358 	     timeout++) {
359 		msleep(1);
360 		temp = inb_p(SMBHSTSTS);
361 	}
362 	if (timeout >= MAX_TIMEOUT) {
363 		dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
364 	}
365 
366 	switch (size) {
367 	case I2C_SMBUS_QUICK:
368 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
369 		       SMBHSTADD);
370 		size = ALI15X3_QUICK;
371 		break;
372 	case I2C_SMBUS_BYTE:
373 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
374 		       SMBHSTADD);
375 		if (read_write == I2C_SMBUS_WRITE)
376 			outb_p(command, SMBHSTCMD);
377 		size = ALI15X3_BYTE;
378 		break;
379 	case I2C_SMBUS_BYTE_DATA:
380 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
381 		       SMBHSTADD);
382 		outb_p(command, SMBHSTCMD);
383 		if (read_write == I2C_SMBUS_WRITE)
384 			outb_p(data->byte, SMBHSTDAT0);
385 		size = ALI15X3_BYTE_DATA;
386 		break;
387 	case I2C_SMBUS_WORD_DATA:
388 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
389 		       SMBHSTADD);
390 		outb_p(command, SMBHSTCMD);
391 		if (read_write == I2C_SMBUS_WRITE) {
392 			outb_p(data->word & 0xff, SMBHSTDAT0);
393 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
394 		}
395 		size = ALI15X3_WORD_DATA;
396 		break;
397 	case I2C_SMBUS_BLOCK_DATA:
398 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
399 		       SMBHSTADD);
400 		outb_p(command, SMBHSTCMD);
401 		if (read_write == I2C_SMBUS_WRITE) {
402 			len = data->block[0];
403 			if (len < 0) {
404 				len = 0;
405 				data->block[0] = len;
406 			}
407 			if (len > 32) {
408 				len = 32;
409 				data->block[0] = len;
410 			}
411 			outb_p(len, SMBHSTDAT0);
412 			/* Reset SMBBLKDAT */
413 			outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
414 			for (i = 1; i <= len; i++)
415 				outb_p(data->block[i], SMBBLKDAT);
416 		}
417 		size = ALI15X3_BLOCK_DATA;
418 		break;
419 	default:
420 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
421 		return -EOPNOTSUPP;
422 	}
423 
424 	outb_p(size, SMBHSTCNT);	/* output command */
425 
426 	temp = ali15x3_transaction(adap);
427 	if (temp)
428 		return temp;
429 
430 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
431 		return 0;
432 
433 
434 	switch (size) {
435 	case ALI15X3_BYTE:	/* Result put in SMBHSTDAT0 */
436 		data->byte = inb_p(SMBHSTDAT0);
437 		break;
438 	case ALI15X3_BYTE_DATA:
439 		data->byte = inb_p(SMBHSTDAT0);
440 		break;
441 	case ALI15X3_WORD_DATA:
442 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
443 		break;
444 	case ALI15X3_BLOCK_DATA:
445 		len = inb_p(SMBHSTDAT0);
446 		if (len > 32)
447 			len = 32;
448 		data->block[0] = len;
449 		/* Reset SMBBLKDAT */
450 		outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
451 		for (i = 1; i <= data->block[0]; i++) {
452 			data->block[i] = inb_p(SMBBLKDAT);
453 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
454 				len, i, data->block[i]);
455 		}
456 		break;
457 	}
458 	return 0;
459 }
460 
461 static u32 ali15x3_func(struct i2c_adapter *adapter)
462 {
463 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
464 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
465 	    I2C_FUNC_SMBUS_BLOCK_DATA;
466 }
467 
468 static const struct i2c_algorithm smbus_algorithm = {
469 	.smbus_xfer	= ali15x3_access,
470 	.functionality	= ali15x3_func,
471 };
472 
473 static struct i2c_adapter ali15x3_adapter = {
474 	.owner		= THIS_MODULE,
475 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
476 	.algo		= &smbus_algorithm,
477 };
478 
479 static const struct pci_device_id ali15x3_ids[] = {
480 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
481 	{ 0, }
482 };
483 
484 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
485 
486 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
487 {
488 	if (ali15x3_setup(dev)) {
489 		dev_err(&dev->dev,
490 			"ALI15X3 not detected, module not inserted.\n");
491 		return -ENODEV;
492 	}
493 
494 	/* set up the sysfs linkage to our parent device */
495 	ali15x3_adapter.dev.parent = &dev->dev;
496 
497 	snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
498 		"SMBus ALI15X3 adapter at %04x", ali15x3_smba);
499 	return i2c_add_adapter(&ali15x3_adapter);
500 }
501 
502 static void ali15x3_remove(struct pci_dev *dev)
503 {
504 	i2c_del_adapter(&ali15x3_adapter);
505 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
506 }
507 
508 static struct pci_driver ali15x3_driver = {
509 	.name		= "ali15x3_smbus",
510 	.id_table	= ali15x3_ids,
511 	.probe		= ali15x3_probe,
512 	.remove		= ali15x3_remove,
513 };
514 
515 module_pci_driver(ali15x3_driver);
516 
517 MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
518 		"Philip Edelbrock <phil@netroedge.com>, "
519 		"and Mark D. Studebaker <mdsxyz123@yahoo.com>");
520 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
521 MODULE_LICENSE("GPL");
522