xref: /openbmc/linux/drivers/i2c/busses/i2c-ali15x3.c (revision 9cfc5c90)
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 
17 /*
18     This is the driver for the SMB Host controller on
19     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
20 
21     The M1543C is a South bridge for desktop systems.
22     The M1533 is a South bridge for portable systems.
23     They are part of the following ALI chipsets:
24        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
25        with AGP and 100MHz CPU Front Side bus
26        "Aladdin V": Includes the M1541 Socket 7 North bridge
27        with AGP and 100MHz CPU Front Side bus
28        "Aladdin IV": Includes the M1541 Socket 7 North bridge
29        with host bus up to 83.3 MHz.
30     For an overview of these chips see http://www.acerlabs.com
31 
32     The M1533/M1543C devices appear as FOUR separate devices
33     on the PCI bus. An output of lspci will show something similar
34     to the following:
35 
36 	00:02.0 USB Controller: Acer Laboratories Inc. M5237
37 	00:03.0 Bridge: Acer Laboratories Inc. M7101
38 	00:07.0 ISA bridge: Acer Laboratories Inc. M1533
39 	00:0f.0 IDE interface: Acer Laboratories Inc. M5229
40 
41     The SMB controller is part of the 7101 device, which is an
42     ACPI-compliant Power Management Unit (PMU).
43 
44     The whole 7101 device has to be enabled for the SMB to work.
45     You can't just enable the SMB alone.
46     The SMB and the ACPI have separate I/O spaces.
47     We make sure that the SMB is enabled. We leave the ACPI alone.
48 
49     This driver controls the SMB Host only.
50     The SMB Slave controller on the M15X3 is not enabled.
51 
52     This driver does not use interrupts.
53 */
54 
55 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
56 
57 #include <linux/module.h>
58 #include <linux/pci.h>
59 #include <linux/kernel.h>
60 #include <linux/stddef.h>
61 #include <linux/ioport.h>
62 #include <linux/delay.h>
63 #include <linux/i2c.h>
64 #include <linux/acpi.h>
65 #include <linux/io.h>
66 
67 /* ALI15X3 SMBus address offsets */
68 #define SMBHSTSTS	(0 + ali15x3_smba)
69 #define SMBHSTCNT	(1 + ali15x3_smba)
70 #define SMBHSTSTART	(2 + ali15x3_smba)
71 #define SMBHSTCMD	(7 + ali15x3_smba)
72 #define SMBHSTADD	(3 + ali15x3_smba)
73 #define SMBHSTDAT0	(4 + ali15x3_smba)
74 #define SMBHSTDAT1	(5 + ali15x3_smba)
75 #define SMBBLKDAT	(6 + ali15x3_smba)
76 
77 /* PCI Address Constants */
78 #define SMBCOM		0x004
79 #define SMBBA		0x014
80 #define SMBATPC		0x05B	/* used to unlock xxxBA registers */
81 #define SMBHSTCFG	0x0E0
82 #define SMBSLVC		0x0E1
83 #define SMBCLK		0x0E2
84 #define SMBREV		0x008
85 
86 /* Other settings */
87 #define MAX_TIMEOUT		200	/* times 1/100 sec */
88 #define ALI15X3_SMB_IOSIZE	32
89 
90 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
91    We don't use these here. If the bases aren't set to some value we
92    tell user to upgrade BIOS and we fail.
93 */
94 #define ALI15X3_SMB_DEFAULTBASE	0xE800
95 
96 /* ALI15X3 address lock bits */
97 #define ALI15X3_LOCK		0x06
98 
99 /* ALI15X3 command constants */
100 #define ALI15X3_ABORT		0x02
101 #define ALI15X3_T_OUT		0x04
102 #define ALI15X3_QUICK		0x00
103 #define ALI15X3_BYTE		0x10
104 #define ALI15X3_BYTE_DATA	0x20
105 #define ALI15X3_WORD_DATA	0x30
106 #define ALI15X3_BLOCK_DATA	0x40
107 #define ALI15X3_BLOCK_CLR	0x80
108 
109 /* ALI15X3 status register bits */
110 #define ALI15X3_STS_IDLE	0x04
111 #define ALI15X3_STS_BUSY	0x08
112 #define ALI15X3_STS_DONE	0x10
113 #define ALI15X3_STS_DEV		0x20	/* device error */
114 #define ALI15X3_STS_COLL	0x40	/* collision or no response */
115 #define ALI15X3_STS_TERM	0x80	/* terminated by abort */
116 #define ALI15X3_STS_ERR		0xE0	/* all the bad error bits */
117 
118 
119 /* If force_addr is set to anything different from 0, we forcibly enable
120    the device at the given address. */
121 static u16 force_addr;
122 module_param(force_addr, ushort, 0);
123 MODULE_PARM_DESC(force_addr,
124 		 "Initialize the base address of the i2c controller");
125 
126 static struct pci_driver ali15x3_driver;
127 static unsigned short ali15x3_smba;
128 
129 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
130 {
131 	u16 a;
132 	unsigned char temp;
133 
134 	/* Check the following things:
135 		- SMB I/O address is initialized
136 		- Device is enabled
137 		- We can use the addresses
138 	*/
139 
140 	/* Unlock the register.
141 	   The data sheet says that the address registers are read-only
142 	   if the lock bits are 1, but in fact the address registers
143 	   are zero unless you clear the lock bits.
144 	*/
145 	pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
146 	if (temp & ALI15X3_LOCK) {
147 		temp &= ~ALI15X3_LOCK;
148 		pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
149 	}
150 
151 	/* Determine the address of the SMBus area */
152 	pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
153 	ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
154 	if (ali15x3_smba == 0 && force_addr == 0) {
155 		dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
156 			"- upgrade BIOS or use force_addr=0xaddr\n");
157 		return -ENODEV;
158 	}
159 
160 	if(force_addr)
161 		ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
162 
163 	if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
164 			      ali15x3_driver.name))
165 		return -EBUSY;
166 
167 	if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
168 			    ali15x3_driver.name)) {
169 		dev_err(&ALI15X3_dev->dev,
170 			"ALI15X3_smb region 0x%x already in use!\n",
171 			ali15x3_smba);
172 		return -ENODEV;
173 	}
174 
175 	if(force_addr) {
176 		dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
177 			ali15x3_smba);
178 		if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
179 								SMBBA,
180 								ali15x3_smba))
181 			goto error;
182 		if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
183 								SMBBA, &a))
184 			goto error;
185 		if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
186 			/* make sure it works */
187 			dev_err(&ALI15X3_dev->dev,
188 				"force address failed - not supported?\n");
189 			goto error;
190 		}
191 	}
192 	/* check if whole device is enabled */
193 	pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
194 	if ((temp & 1) == 0) {
195 		dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
196 		pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
197 	}
198 
199 	/* Is SMB Host controller enabled? */
200 	pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
201 	if ((temp & 1) == 0) {
202 		dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
203 		pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
204 	}
205 
206 	/* set SMB clock to 74KHz as recommended in data sheet */
207 	pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
208 
209 	/*
210 	  The interrupt routing for SMB is set up in register 0x77 in the
211 	  1533 ISA Bridge device, NOT in the 7101 device.
212 	  Don't bother with finding the 1533 device and reading the register.
213 	if ((....... & 0x0F) == 1)
214 		dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
215 	*/
216 	pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
217 	dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
218 	dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
219 
220 	return 0;
221 error:
222 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
223 	return -ENODEV;
224 }
225 
226 /* Another internally used function */
227 static int ali15x3_transaction(struct i2c_adapter *adap)
228 {
229 	int temp;
230 	int result = 0;
231 	int timeout = 0;
232 
233 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
234 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
235 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
236 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
237 
238 	/* get status */
239 	temp = inb_p(SMBHSTSTS);
240 
241 	/* Make sure the SMBus host is ready to start transmitting */
242 	/* Check the busy bit first */
243 	if (temp & ALI15X3_STS_BUSY) {
244 	/*
245 	   If the host controller is still busy, it may have timed out in the
246 	   previous transaction, resulting in a "SMBus Timeout" Dev.
247 	   I've tried the following to reset a stuck busy bit.
248 		1. Reset the controller with an ABORT command.
249 		   (this doesn't seem to clear the controller if an external
250 		   device is hung)
251 		2. Reset the controller and the other SMBus devices with a
252 		   T_OUT command.  (this clears the host busy bit if an
253 		   external device is hung, but it comes back upon a new access
254 		   to a device)
255 		3. Disable and reenable the controller in SMBHSTCFG
256 	   Worst case, nothing seems to work except power reset.
257 	*/
258 	/* Abort - reset the host controller */
259 	/*
260 	   Try resetting entire SMB bus, including other devices -
261 	   This may not work either - it clears the BUSY bit but
262 	   then the BUSY bit may come back on when you try and use the chip again.
263 	   If that's the case you are stuck.
264 	*/
265 		dev_info(&adap->dev, "Resetting entire SMB Bus to "
266 			"clear busy condition (%02x)\n", temp);
267 		outb_p(ALI15X3_T_OUT, SMBHSTCNT);
268 		temp = inb_p(SMBHSTSTS);
269 	}
270 
271 	/* now check the error bits and the busy bit */
272 	if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
273 		/* do a clear-on-write */
274 		outb_p(0xFF, SMBHSTSTS);
275 		if ((temp = inb_p(SMBHSTSTS)) &
276 		    (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
277 			/* this is probably going to be correctable only by a power reset
278 			   as one of the bits now appears to be stuck */
279 			/* This may be a bus or device with electrical problems. */
280 			dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
281 				"controller or device on bus is probably hung\n",
282 				temp);
283 			return -EBUSY;
284 		}
285 	} else {
286 		/* check and clear done bit */
287 		if (temp & ALI15X3_STS_DONE) {
288 			outb_p(temp, SMBHSTSTS);
289 		}
290 	}
291 
292 	/* start the transaction by writing anything to the start register */
293 	outb_p(0xFF, SMBHSTSTART);
294 
295 	/* We will always wait for a fraction of a second! */
296 	timeout = 0;
297 	do {
298 		msleep(1);
299 		temp = inb_p(SMBHSTSTS);
300 	} while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
301 		 && (timeout++ < MAX_TIMEOUT));
302 
303 	/* If the SMBus is still busy, we give up */
304 	if (timeout > MAX_TIMEOUT) {
305 		result = -ETIMEDOUT;
306 		dev_err(&adap->dev, "SMBus Timeout!\n");
307 	}
308 
309 	if (temp & ALI15X3_STS_TERM) {
310 		result = -EIO;
311 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
312 	}
313 
314 	/*
315 	  Unfortunately the ALI SMB controller maps "no response" and "bus
316 	  collision" into a single bit. No response is the usual case so don't
317 	  do a printk.
318 	  This means that bus collisions go unreported.
319 	*/
320 	if (temp & ALI15X3_STS_COLL) {
321 		result = -ENXIO;
322 		dev_dbg(&adap->dev,
323 			"Error: no response or bus collision ADD=%02x\n",
324 			inb_p(SMBHSTADD));
325 	}
326 
327 	/* haven't ever seen this */
328 	if (temp & ALI15X3_STS_DEV) {
329 		result = -EIO;
330 		dev_err(&adap->dev, "Error: device error\n");
331 	}
332 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
333 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
334 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
335 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
336 	return result;
337 }
338 
339 /* Return negative errno on error. */
340 static s32 ali15x3_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 
348 	/* clear all the bits (clear-on-write) */
349 	outb_p(0xFF, SMBHSTSTS);
350 	/* make sure SMBus is idle */
351 	temp = inb_p(SMBHSTSTS);
352 	for (timeout = 0;
353 	     (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
354 	     timeout++) {
355 		msleep(1);
356 		temp = inb_p(SMBHSTSTS);
357 	}
358 	if (timeout >= MAX_TIMEOUT) {
359 		dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
360 	}
361 
362 	switch (size) {
363 	case I2C_SMBUS_QUICK:
364 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
365 		       SMBHSTADD);
366 		size = ALI15X3_QUICK;
367 		break;
368 	case I2C_SMBUS_BYTE:
369 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
370 		       SMBHSTADD);
371 		if (read_write == I2C_SMBUS_WRITE)
372 			outb_p(command, SMBHSTCMD);
373 		size = ALI15X3_BYTE;
374 		break;
375 	case I2C_SMBUS_BYTE_DATA:
376 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
377 		       SMBHSTADD);
378 		outb_p(command, SMBHSTCMD);
379 		if (read_write == I2C_SMBUS_WRITE)
380 			outb_p(data->byte, SMBHSTDAT0);
381 		size = ALI15X3_BYTE_DATA;
382 		break;
383 	case I2C_SMBUS_WORD_DATA:
384 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
385 		       SMBHSTADD);
386 		outb_p(command, SMBHSTCMD);
387 		if (read_write == I2C_SMBUS_WRITE) {
388 			outb_p(data->word & 0xff, SMBHSTDAT0);
389 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
390 		}
391 		size = ALI15X3_WORD_DATA;
392 		break;
393 	case I2C_SMBUS_BLOCK_DATA:
394 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
395 		       SMBHSTADD);
396 		outb_p(command, SMBHSTCMD);
397 		if (read_write == I2C_SMBUS_WRITE) {
398 			len = data->block[0];
399 			if (len < 0) {
400 				len = 0;
401 				data->block[0] = len;
402 			}
403 			if (len > 32) {
404 				len = 32;
405 				data->block[0] = len;
406 			}
407 			outb_p(len, SMBHSTDAT0);
408 			/* Reset SMBBLKDAT */
409 			outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
410 			for (i = 1; i <= len; i++)
411 				outb_p(data->block[i], SMBBLKDAT);
412 		}
413 		size = ALI15X3_BLOCK_DATA;
414 		break;
415 	default:
416 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
417 		return -EOPNOTSUPP;
418 	}
419 
420 	outb_p(size, SMBHSTCNT);	/* output command */
421 
422 	temp = ali15x3_transaction(adap);
423 	if (temp)
424 		return temp;
425 
426 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
427 		return 0;
428 
429 
430 	switch (size) {
431 	case ALI15X3_BYTE:	/* Result put in SMBHSTDAT0 */
432 		data->byte = inb_p(SMBHSTDAT0);
433 		break;
434 	case ALI15X3_BYTE_DATA:
435 		data->byte = inb_p(SMBHSTDAT0);
436 		break;
437 	case ALI15X3_WORD_DATA:
438 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
439 		break;
440 	case ALI15X3_BLOCK_DATA:
441 		len = inb_p(SMBHSTDAT0);
442 		if (len > 32)
443 			len = 32;
444 		data->block[0] = len;
445 		/* Reset SMBBLKDAT */
446 		outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
447 		for (i = 1; i <= data->block[0]; i++) {
448 			data->block[i] = inb_p(SMBBLKDAT);
449 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
450 				len, i, data->block[i]);
451 		}
452 		break;
453 	}
454 	return 0;
455 }
456 
457 static u32 ali15x3_func(struct i2c_adapter *adapter)
458 {
459 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
460 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
461 	    I2C_FUNC_SMBUS_BLOCK_DATA;
462 }
463 
464 static const struct i2c_algorithm smbus_algorithm = {
465 	.smbus_xfer	= ali15x3_access,
466 	.functionality	= ali15x3_func,
467 };
468 
469 static struct i2c_adapter ali15x3_adapter = {
470 	.owner		= THIS_MODULE,
471 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
472 	.algo		= &smbus_algorithm,
473 };
474 
475 static const struct pci_device_id ali15x3_ids[] = {
476 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
477 	{ 0, }
478 };
479 
480 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
481 
482 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
483 {
484 	if (ali15x3_setup(dev)) {
485 		dev_err(&dev->dev,
486 			"ALI15X3 not detected, module not inserted.\n");
487 		return -ENODEV;
488 	}
489 
490 	/* set up the sysfs linkage to our parent device */
491 	ali15x3_adapter.dev.parent = &dev->dev;
492 
493 	snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
494 		"SMBus ALI15X3 adapter at %04x", ali15x3_smba);
495 	return i2c_add_adapter(&ali15x3_adapter);
496 }
497 
498 static void ali15x3_remove(struct pci_dev *dev)
499 {
500 	i2c_del_adapter(&ali15x3_adapter);
501 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
502 }
503 
504 static struct pci_driver ali15x3_driver = {
505 	.name		= "ali15x3_smbus",
506 	.id_table	= ali15x3_ids,
507 	.probe		= ali15x3_probe,
508 	.remove		= ali15x3_remove,
509 };
510 
511 module_pci_driver(ali15x3_driver);
512 
513 MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
514 		"Philip Edelbrock <phil@netroedge.com>, "
515 		"and Mark D. Studebaker <mdsxyz123@yahoo.com>");
516 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
517 MODULE_LICENSE("GPL");
518