xref: /linux/drivers/i2c/busses/i2c-ali15x3.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
4     Philip Edelbrock <phil@netroedge.com> and
5     Mark D. Studebaker <mdsxyz123@yahoo.com>
6 
7 */
8 
9 /*
10     This is the driver for the SMB Host controller on
11     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
12 
13     The M1543C is a South bridge for desktop systems.
14     The M1533 is a South bridge for portable systems.
15     They are part of the following ALI chipsets:
16        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
17        with AGP and 100MHz CPU Front Side bus
18        "Aladdin V": Includes the M1541 Socket 7 North bridge
19        with AGP and 100MHz CPU Front Side bus
20        "Aladdin IV": Includes the M1541 Socket 7 North bridge
21        with host bus up to 83.3 MHz.
22     For an overview of these chips see http://www.acerlabs.com
23 
24     The M1533/M1543C devices appear as FOUR separate devices
25     on the PCI bus. An output of lspci will show something similar
26     to the following:
27 
28 	00:02.0 USB Controller: Acer Laboratories Inc. M5237
29 	00:03.0 Bridge: Acer Laboratories Inc. M7101
30 	00:07.0 ISA bridge: Acer Laboratories Inc. M1533
31 	00:0f.0 IDE interface: Acer Laboratories Inc. M5229
32 
33     The SMB controller is part of the 7101 device, which is an
34     ACPI-compliant Power Management Unit (PMU).
35 
36     The whole 7101 device has to be enabled for the SMB to work.
37     You can't just enable the SMB alone.
38     The SMB and the ACPI have separate I/O spaces.
39     We make sure that the SMB is enabled. We leave the ACPI alone.
40 
41     This driver controls the SMB Host only.
42     The SMB Slave controller on the M15X3 is not enabled.
43 
44     This driver does not use interrupts.
45 */
46 
47 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
48 
49 #include <linux/module.h>
50 #include <linux/pci.h>
51 #include <linux/kernel.h>
52 #include <linux/stddef.h>
53 #include <linux/ioport.h>
54 #include <linux/delay.h>
55 #include <linux/i2c.h>
56 #include <linux/acpi.h>
57 #include <linux/io.h>
58 
59 /* ALI15X3 SMBus address offsets */
60 #define SMBHSTSTS	(0 + ali15x3_smba)
61 #define SMBHSTCNT	(1 + ali15x3_smba)
62 #define SMBHSTSTART	(2 + ali15x3_smba)
63 #define SMBHSTCMD	(7 + ali15x3_smba)
64 #define SMBHSTADD	(3 + ali15x3_smba)
65 #define SMBHSTDAT0	(4 + ali15x3_smba)
66 #define SMBHSTDAT1	(5 + ali15x3_smba)
67 #define SMBBLKDAT	(6 + ali15x3_smba)
68 
69 /* PCI Address Constants */
70 #define SMBCOM		0x004
71 #define SMBBA		0x014
72 #define SMBATPC		0x05B	/* used to unlock xxxBA registers */
73 #define SMBHSTCFG	0x0E0
74 #define SMBSLVC		0x0E1
75 #define SMBCLK		0x0E2
76 #define SMBREV		0x008
77 
78 /* Other settings */
79 #define MAX_TIMEOUT		200	/* times 1/100 sec */
80 #define ALI15X3_SMB_IOSIZE	32
81 
82 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
83    We don't use these here. If the bases aren't set to some value we
84    tell user to upgrade BIOS and we fail.
85 */
86 #define ALI15X3_SMB_DEFAULTBASE	0xE800
87 
88 /* ALI15X3 address lock bits */
89 #define ALI15X3_LOCK		0x06
90 
91 /* ALI15X3 command constants */
92 #define ALI15X3_ABORT		0x02
93 #define ALI15X3_T_OUT		0x04
94 #define ALI15X3_QUICK		0x00
95 #define ALI15X3_BYTE		0x10
96 #define ALI15X3_BYTE_DATA	0x20
97 #define ALI15X3_WORD_DATA	0x30
98 #define ALI15X3_BLOCK_DATA	0x40
99 #define ALI15X3_BLOCK_CLR	0x80
100 
101 /* ALI15X3 status register bits */
102 #define ALI15X3_STS_IDLE	0x04
103 #define ALI15X3_STS_BUSY	0x08
104 #define ALI15X3_STS_DONE	0x10
105 #define ALI15X3_STS_DEV		0x20	/* device error */
106 #define ALI15X3_STS_COLL	0x40	/* collision or no response */
107 #define ALI15X3_STS_TERM	0x80	/* terminated by abort */
108 #define ALI15X3_STS_ERR		0xE0	/* all the bad error bits */
109 
110 
111 /* If force_addr is set to anything different from 0, we forcibly enable
112    the device at the given address. */
113 static u16 force_addr;
114 module_param_hw(force_addr, ushort, ioport, 0);
115 MODULE_PARM_DESC(force_addr,
116 		 "Initialize the base address of the i2c controller");
117 
118 static struct pci_driver ali15x3_driver;
119 static unsigned short ali15x3_smba;
120 
121 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
122 {
123 	u16 a;
124 	unsigned char temp;
125 
126 	/* Check the following things:
127 		- SMB I/O address is initialized
128 		- Device is enabled
129 		- We can use the addresses
130 	*/
131 
132 	/* Unlock the register.
133 	   The data sheet says that the address registers are read-only
134 	   if the lock bits are 1, but in fact the address registers
135 	   are zero unless you clear the lock bits.
136 	*/
137 	pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
138 	if (temp & ALI15X3_LOCK) {
139 		temp &= ~ALI15X3_LOCK;
140 		pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
141 	}
142 
143 	/* Determine the address of the SMBus area */
144 	pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
145 	ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
146 	if (ali15x3_smba == 0 && force_addr == 0) {
147 		dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
148 			"- upgrade BIOS or use force_addr=0xaddr\n");
149 		return -ENODEV;
150 	}
151 
152 	if(force_addr)
153 		ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
154 
155 	if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
156 			      ali15x3_driver.name))
157 		return -EBUSY;
158 
159 	if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
160 			    ali15x3_driver.name)) {
161 		dev_err(&ALI15X3_dev->dev,
162 			"ALI15X3_smb region 0x%x already in use!\n",
163 			ali15x3_smba);
164 		return -ENODEV;
165 	}
166 
167 	if(force_addr) {
168 		int ret;
169 
170 		dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
171 			ali15x3_smba);
172 		ret = pci_write_config_word(ALI15X3_dev, SMBBA, ali15x3_smba);
173 		if (ret != PCIBIOS_SUCCESSFUL)
174 			goto error;
175 		ret = pci_read_config_word(ALI15X3_dev, SMBBA, &a);
176 		if (ret != PCIBIOS_SUCCESSFUL)
177 			goto error;
178 		if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
179 			/* make sure it works */
180 			dev_err(&ALI15X3_dev->dev,
181 				"force address failed - not supported?\n");
182 			goto error;
183 		}
184 	}
185 	/* check if whole device is enabled */
186 	pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
187 	if ((temp & 1) == 0) {
188 		dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
189 		pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
190 	}
191 
192 	/* Is SMB Host controller enabled? */
193 	pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
194 	if ((temp & 1) == 0) {
195 		dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
196 		pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
197 	}
198 
199 	/* set SMB clock to 74KHz as recommended in data sheet */
200 	pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
201 
202 	/*
203 	  The interrupt routing for SMB is set up in register 0x77 in the
204 	  1533 ISA Bridge device, NOT in the 7101 device.
205 	  Don't bother with finding the 1533 device and reading the register.
206 	if ((....... & 0x0F) == 1)
207 		dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
208 	*/
209 	pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
210 	dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
211 	dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
212 
213 	return 0;
214 error:
215 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
216 	return -ENODEV;
217 }
218 
219 /* Another internally used function */
220 static int ali15x3_transaction(struct i2c_adapter *adap)
221 {
222 	int temp;
223 	int result = 0;
224 	int timeout = 0;
225 
226 	dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
227 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
228 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
229 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
230 
231 	/* get status */
232 	temp = inb_p(SMBHSTSTS);
233 
234 	/* Make sure the SMBus host is ready to start transmitting */
235 	/* Check the busy bit first */
236 	if (temp & ALI15X3_STS_BUSY) {
237 	/*
238 	   If the host controller is still busy, it may have timed out in the
239 	   previous transaction, resulting in a "SMBus Timeout" Dev.
240 	   I've tried the following to reset a stuck busy bit.
241 		1. Reset the controller with an ABORT command.
242 		   (this doesn't seem to clear the controller if an external
243 		   device is hung)
244 		2. Reset the controller and the other SMBus devices with a
245 		   T_OUT command.  (this clears the host busy bit if an
246 		   external device is hung, but it comes back upon a new access
247 		   to a device)
248 		3. Disable and reenable the controller in SMBHSTCFG
249 	   Worst case, nothing seems to work except power reset.
250 	*/
251 	/* Abort - reset the host controller */
252 	/*
253 	   Try resetting entire SMB bus, including other devices -
254 	   This may not work either - it clears the BUSY bit but
255 	   then the BUSY bit may come back on when you try and use the chip again.
256 	   If that's the case you are stuck.
257 	*/
258 		dev_info(&adap->dev, "Resetting entire SMB Bus to "
259 			"clear busy condition (%02x)\n", temp);
260 		outb_p(ALI15X3_T_OUT, SMBHSTCNT);
261 		temp = inb_p(SMBHSTSTS);
262 	}
263 
264 	/* now check the error bits and the busy bit */
265 	if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
266 		/* do a clear-on-write */
267 		outb_p(0xFF, SMBHSTSTS);
268 		if ((temp = inb_p(SMBHSTSTS)) &
269 		    (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
270 			/* this is probably going to be correctable only by a power reset
271 			   as one of the bits now appears to be stuck */
272 			/* This may be a bus or device with electrical problems. */
273 			dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
274 				"controller or device on bus is probably hung\n",
275 				temp);
276 			return -EBUSY;
277 		}
278 	} else {
279 		/* check and clear done bit */
280 		if (temp & ALI15X3_STS_DONE) {
281 			outb_p(temp, SMBHSTSTS);
282 		}
283 	}
284 
285 	/* start the transaction by writing anything to the start register */
286 	outb_p(0xFF, SMBHSTSTART);
287 
288 	/* We will always wait for a fraction of a second! */
289 	timeout = 0;
290 	do {
291 		msleep(1);
292 		temp = inb_p(SMBHSTSTS);
293 	} while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
294 		 && (timeout++ < MAX_TIMEOUT));
295 
296 	/* If the SMBus is still busy, we give up */
297 	if (timeout > MAX_TIMEOUT) {
298 		result = -ETIMEDOUT;
299 		dev_err(&adap->dev, "SMBus Timeout!\n");
300 	}
301 
302 	if (temp & ALI15X3_STS_TERM) {
303 		result = -EIO;
304 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
305 	}
306 
307 	/*
308 	  Unfortunately the ALI SMB controller maps "no response" and "bus
309 	  collision" into a single bit. No response is the usual case so don't
310 	  do a printk.
311 	  This means that bus collisions go unreported.
312 	*/
313 	if (temp & ALI15X3_STS_COLL) {
314 		result = -ENXIO;
315 		dev_dbg(&adap->dev,
316 			"Error: no response or bus collision ADD=%02x\n",
317 			inb_p(SMBHSTADD));
318 	}
319 
320 	/* haven't ever seen this */
321 	if (temp & ALI15X3_STS_DEV) {
322 		result = -EIO;
323 		dev_err(&adap->dev, "Error: device error\n");
324 	}
325 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
326 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
327 		inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
328 		inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
329 	return result;
330 }
331 
332 /* Return negative errno on error. */
333 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
334 		   unsigned short flags, char read_write, u8 command,
335 		   int size, union i2c_smbus_data * data)
336 {
337 	int i, len;
338 	int temp;
339 	int timeout;
340 
341 	/* clear all the bits (clear-on-write) */
342 	outb_p(0xFF, SMBHSTSTS);
343 	/* make sure SMBus is idle */
344 	temp = inb_p(SMBHSTSTS);
345 	for (timeout = 0;
346 	     (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
347 	     timeout++) {
348 		msleep(1);
349 		temp = inb_p(SMBHSTSTS);
350 	}
351 	if (timeout >= MAX_TIMEOUT) {
352 		dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
353 	}
354 
355 	switch (size) {
356 	case I2C_SMBUS_QUICK:
357 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
358 		       SMBHSTADD);
359 		size = ALI15X3_QUICK;
360 		break;
361 	case I2C_SMBUS_BYTE:
362 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
363 		       SMBHSTADD);
364 		if (read_write == I2C_SMBUS_WRITE)
365 			outb_p(command, SMBHSTCMD);
366 		size = ALI15X3_BYTE;
367 		break;
368 	case I2C_SMBUS_BYTE_DATA:
369 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
370 		       SMBHSTADD);
371 		outb_p(command, SMBHSTCMD);
372 		if (read_write == I2C_SMBUS_WRITE)
373 			outb_p(data->byte, SMBHSTDAT0);
374 		size = ALI15X3_BYTE_DATA;
375 		break;
376 	case I2C_SMBUS_WORD_DATA:
377 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
378 		       SMBHSTADD);
379 		outb_p(command, SMBHSTCMD);
380 		if (read_write == I2C_SMBUS_WRITE) {
381 			outb_p(data->word & 0xff, SMBHSTDAT0);
382 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
383 		}
384 		size = ALI15X3_WORD_DATA;
385 		break;
386 	case I2C_SMBUS_BLOCK_DATA:
387 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
388 		       SMBHSTADD);
389 		outb_p(command, SMBHSTCMD);
390 		if (read_write == I2C_SMBUS_WRITE) {
391 			len = data->block[0];
392 			if (len < 0) {
393 				len = 0;
394 				data->block[0] = len;
395 			}
396 			if (len > 32) {
397 				len = 32;
398 				data->block[0] = len;
399 			}
400 			outb_p(len, SMBHSTDAT0);
401 			/* Reset SMBBLKDAT */
402 			outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
403 			for (i = 1; i <= len; i++)
404 				outb_p(data->block[i], SMBBLKDAT);
405 		}
406 		size = ALI15X3_BLOCK_DATA;
407 		break;
408 	default:
409 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
410 		return -EOPNOTSUPP;
411 	}
412 
413 	outb_p(size, SMBHSTCNT);	/* output command */
414 
415 	temp = ali15x3_transaction(adap);
416 	if (temp)
417 		return temp;
418 
419 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
420 		return 0;
421 
422 
423 	switch (size) {
424 	case ALI15X3_BYTE:	/* Result put in SMBHSTDAT0 */
425 		data->byte = inb_p(SMBHSTDAT0);
426 		break;
427 	case ALI15X3_BYTE_DATA:
428 		data->byte = inb_p(SMBHSTDAT0);
429 		break;
430 	case ALI15X3_WORD_DATA:
431 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
432 		break;
433 	case ALI15X3_BLOCK_DATA:
434 		len = inb_p(SMBHSTDAT0);
435 		if (len > 32)
436 			len = 32;
437 		data->block[0] = len;
438 		/* Reset SMBBLKDAT */
439 		outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
440 		for (i = 1; i <= data->block[0]; i++) {
441 			data->block[i] = inb_p(SMBBLKDAT);
442 			dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
443 				len, i, data->block[i]);
444 		}
445 		break;
446 	}
447 	return 0;
448 }
449 
450 static u32 ali15x3_func(struct i2c_adapter *adapter)
451 {
452 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
453 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
454 	    I2C_FUNC_SMBUS_BLOCK_DATA;
455 }
456 
457 static const struct i2c_algorithm smbus_algorithm = {
458 	.smbus_xfer	= ali15x3_access,
459 	.functionality	= ali15x3_func,
460 };
461 
462 static struct i2c_adapter ali15x3_adapter = {
463 	.owner		= THIS_MODULE,
464 	.class          = I2C_CLASS_HWMON,
465 	.algo		= &smbus_algorithm,
466 };
467 
468 static const struct pci_device_id ali15x3_ids[] = {
469 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
470 	{ 0, }
471 };
472 
473 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
474 
475 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
476 {
477 	if (ali15x3_setup(dev)) {
478 		dev_err(&dev->dev,
479 			"ALI15X3 not detected, module not inserted.\n");
480 		return -ENODEV;
481 	}
482 
483 	/* set up the sysfs linkage to our parent device */
484 	ali15x3_adapter.dev.parent = &dev->dev;
485 
486 	snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
487 		"SMBus ALI15X3 adapter at %04x", ali15x3_smba);
488 	return i2c_add_adapter(&ali15x3_adapter);
489 }
490 
491 static void ali15x3_remove(struct pci_dev *dev)
492 {
493 	i2c_del_adapter(&ali15x3_adapter);
494 	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
495 }
496 
497 static struct pci_driver ali15x3_driver = {
498 	.name		= "ali15x3_smbus",
499 	.id_table	= ali15x3_ids,
500 	.probe		= ali15x3_probe,
501 	.remove		= ali15x3_remove,
502 };
503 
504 module_pci_driver(ali15x3_driver);
505 
506 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
507 MODULE_AUTHOR("Philip Edelbrock <phil@netroedge.com>");
508 MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
509 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
510 MODULE_LICENSE("GPL");
511