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. */
113static u16 force_addr;
114module_param_hw(force_addr, ushort, ioport, 0);
115MODULE_PARM_DESC(force_addr,
116		 "Initialize the base address of the i2c controller");
117
118static struct pci_driver ali15x3_driver;
119static unsigned short ali15x3_smba;
120
121static 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;
214error:
215	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
216	return -ENODEV;
217}
218
219/* Another internally used function */
220static 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. */
333static 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
450static 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
457static const struct i2c_algorithm smbus_algorithm = {
458	.smbus_xfer	= ali15x3_access,
459	.functionality	= ali15x3_func,
460};
461
462static struct i2c_adapter ali15x3_adapter = {
463	.owner		= THIS_MODULE,
464	.class          = I2C_CLASS_HWMON,
465	.algo		= &smbus_algorithm,
466};
467
468static const struct pci_device_id ali15x3_ids[] = {
469	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
470	{ 0, }
471};
472
473MODULE_DEVICE_TABLE (pci, ali15x3_ids);
474
475static 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
491static void ali15x3_remove(struct pci_dev *dev)
492{
493	i2c_del_adapter(&ali15x3_adapter);
494	release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
495}
496
497static struct pci_driver ali15x3_driver = {
498	.name		= "ali15x3_smbus",
499	.id_table	= ali15x3_ids,
500	.probe		= ali15x3_probe,
501	.remove		= ali15x3_remove,
502};
503
504module_pci_driver(ali15x3_driver);
505
506MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
507MODULE_AUTHOR("Philip Edelbrock <phil@netroedge.com>");
508MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
509MODULE_DESCRIPTION("ALI15X3 SMBus driver");
510MODULE_LICENSE("GPL");
511