1/*
2    Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
3    Philip Edelbrock <phil@netroedge.com>
4
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 2 of the License, or
8    (at your option) any later version.
9
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14*/
15
16/* Note: we assume there can only be one SIS5595 with one SMBus interface */
17
18/*
19   Note: all have mfr. ID 0x1039.
20   SUPPORTED		PCI ID
21	5595		0008
22
23   Note: these chips contain a 0008 device which is incompatible with the
24         5595. We recognize these by the presence of the listed
25         "blacklist" PCI ID and refuse to load.
26
27   NOT SUPPORTED	PCI ID		BLACKLIST PCI ID
28	 540		0008		0540
29	 550		0008		0550
30	5513		0008		5511
31	5581		0008		5597
32	5582		0008		5597
33	5597		0008		5597
34	5598		0008		5597/5598
35	 630		0008		0630
36	 645		0008		0645
37	 646		0008		0646
38	 648		0008		0648
39	 650		0008		0650
40	 651		0008		0651
41	 730		0008		0730
42	 735		0008		0735
43	 745		0008		0745
44	 746		0008		0746
45*/
46
47/* TO DO:
48 * Add Block Transfers (ugly, but supported by the adapter)
49 * Add adapter resets
50 */
51
52#include <linux/kernel.h>
53#include <linux/module.h>
54#include <linux/delay.h>
55#include <linux/pci.h>
56#include <linux/ioport.h>
57#include <linux/init.h>
58#include <linux/i2c.h>
59#include <linux/acpi.h>
60#include <linux/io.h>
61
62static int blacklist[] = {
63	PCI_DEVICE_ID_SI_540,
64	PCI_DEVICE_ID_SI_550,
65	PCI_DEVICE_ID_SI_630,
66	PCI_DEVICE_ID_SI_645,
67	PCI_DEVICE_ID_SI_646,
68	PCI_DEVICE_ID_SI_648,
69	PCI_DEVICE_ID_SI_650,
70	PCI_DEVICE_ID_SI_651,
71	PCI_DEVICE_ID_SI_730,
72	PCI_DEVICE_ID_SI_735,
73	PCI_DEVICE_ID_SI_745,
74	PCI_DEVICE_ID_SI_746,
75	PCI_DEVICE_ID_SI_5511,	/* 5513 chip has the 0008 device but that ID
76				   shows up in other chips so we use the 5511
77				   ID for recognition */
78	PCI_DEVICE_ID_SI_5597,
79	PCI_DEVICE_ID_SI_5598,
80	0,			/* terminates the list */
81};
82
83/* Length of ISA address segment */
84#define SIS5595_EXTENT		8
85/* SIS5595 SMBus registers */
86#define SMB_STS_LO		0x00
87#define SMB_STS_HI		0x01
88#define SMB_CTL_LO		0x02
89#define SMB_CTL_HI		0x03
90#define SMB_ADDR		0x04
91#define SMB_CMD			0x05
92#define SMB_PCNT		0x06
93#define SMB_CNT			0x07
94#define SMB_BYTE		0x08
95#define SMB_DEV			0x10
96#define SMB_DB0			0x11
97#define SMB_DB1			0x12
98#define SMB_HAA			0x13
99
100/* PCI Address Constants */
101#define SMB_INDEX		0x38
102#define SMB_DAT			0x39
103#define SIS5595_ENABLE_REG	0x40
104#define ACPI_BASE		0x90
105
106/* Other settings */
107#define MAX_TIMEOUT		500
108
109/* SIS5595 constants */
110#define SIS5595_QUICK		0x00
111#define SIS5595_BYTE		0x02
112#define SIS5595_BYTE_DATA	0x04
113#define SIS5595_WORD_DATA	0x06
114#define SIS5595_PROC_CALL	0x08
115#define SIS5595_BLOCK_DATA	0x0A
116
117/* insmod parameters */
118
119/* If force_addr is set to anything different from 0, we forcibly enable
120   the device at the given address. */
121static u16 force_addr;
122module_param(force_addr, ushort, 0);
123MODULE_PARM_DESC(force_addr, "Initialize the base address of the i2c controller");
124
125static struct pci_driver sis5595_driver;
126static unsigned short sis5595_base;
127static struct pci_dev *sis5595_pdev;
128
129static u8 sis5595_read(u8 reg)
130{
131	outb(reg, sis5595_base + SMB_INDEX);
132	return inb(sis5595_base + SMB_DAT);
133}
134
135static void sis5595_write(u8 reg, u8 data)
136{
137	outb(reg, sis5595_base + SMB_INDEX);
138	outb(data, sis5595_base + SMB_DAT);
139}
140
141static int sis5595_setup(struct pci_dev *SIS5595_dev)
142{
143	u16 a;
144	u8 val;
145	int *i;
146	int retval;
147
148	/* Look for imposters */
149	for (i = blacklist; *i != 0; i++) {
150		struct pci_dev *dev;
151		dev = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
152		if (dev) {
153			dev_err(&SIS5595_dev->dev, "Looked for SIS5595 but found unsupported device %.4x\n", *i);
154			pci_dev_put(dev);
155			return -ENODEV;
156		}
157	}
158
159	/* Determine the address of the SMBus areas */
160	pci_read_config_word(SIS5595_dev, ACPI_BASE, &sis5595_base);
161	if (sis5595_base == 0 && force_addr == 0) {
162		dev_err(&SIS5595_dev->dev, "ACPI base address uninitialized - upgrade BIOS or use force_addr=0xaddr\n");
163		return -ENODEV;
164	}
165
166	if (force_addr)
167		sis5595_base = force_addr & ~(SIS5595_EXTENT - 1);
168	dev_dbg(&SIS5595_dev->dev, "ACPI Base address: %04x\n", sis5595_base);
169
170	/* NB: We grab just the two SMBus registers here, but this may still
171	 * interfere with ACPI :-(  */
172	retval = acpi_check_region(sis5595_base + SMB_INDEX, 2,
173				   sis5595_driver.name);
174	if (retval)
175		return retval;
176
177	if (!request_region(sis5595_base + SMB_INDEX, 2,
178			    sis5595_driver.name)) {
179		dev_err(&SIS5595_dev->dev, "SMBus registers 0x%04x-0x%04x already in use!\n",
180			sis5595_base + SMB_INDEX, sis5595_base + SMB_INDEX + 1);
181		return -ENODEV;
182	}
183
184	if (force_addr) {
185		dev_info(&SIS5595_dev->dev, "forcing ISA address 0x%04X\n", sis5595_base);
186		if (pci_write_config_word(SIS5595_dev, ACPI_BASE, sis5595_base)
187		    != PCIBIOS_SUCCESSFUL)
188			goto error;
189		if (pci_read_config_word(SIS5595_dev, ACPI_BASE, &a)
190		    != PCIBIOS_SUCCESSFUL)
191			goto error;
192		if ((a & ~(SIS5595_EXTENT - 1)) != sis5595_base) {
193			/* doesn't work for some chips! */
194			dev_err(&SIS5595_dev->dev, "force address failed - not supported?\n");
195			goto error;
196		}
197	}
198
199	if (pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val)
200	    != PCIBIOS_SUCCESSFUL)
201		goto error;
202	if ((val & 0x80) == 0) {
203		dev_info(&SIS5595_dev->dev, "enabling ACPI\n");
204		if (pci_write_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, val | 0x80)
205		    != PCIBIOS_SUCCESSFUL)
206			goto error;
207		if (pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val)
208		    != PCIBIOS_SUCCESSFUL)
209			goto error;
210		if ((val & 0x80) == 0) {
211			/* doesn't work for some chips? */
212			dev_err(&SIS5595_dev->dev, "ACPI enable failed - not supported?\n");
213			goto error;
214		}
215	}
216
217	/* Everything is happy */
218	return 0;
219
220error:
221	release_region(sis5595_base + SMB_INDEX, 2);
222	return -ENODEV;
223}
224
225static int sis5595_transaction(struct i2c_adapter *adap)
226{
227	int temp;
228	int result = 0;
229	int timeout = 0;
230
231	/* Make sure the SMBus host is ready to start transmitting */
232	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
233	if (temp != 0x00) {
234		dev_dbg(&adap->dev, "SMBus busy (%04x). Resetting...\n", temp);
235		sis5595_write(SMB_STS_LO, temp & 0xff);
236		sis5595_write(SMB_STS_HI, temp >> 8);
237		if ((temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8)) != 0x00) {
238			dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
239			return -EBUSY;
240		} else {
241			dev_dbg(&adap->dev, "Successful!\n");
242		}
243	}
244
245	/* start the transaction by setting bit 4 */
246	sis5595_write(SMB_CTL_LO, sis5595_read(SMB_CTL_LO) | 0x10);
247
248	/* We will always wait for a fraction of a second! */
249	do {
250		msleep(1);
251		temp = sis5595_read(SMB_STS_LO);
252	} while (!(temp & 0x40) && (timeout++ < MAX_TIMEOUT));
253
254	/* If the SMBus is still busy, we give up */
255	if (timeout > MAX_TIMEOUT) {
256		dev_dbg(&adap->dev, "SMBus Timeout!\n");
257		result = -ETIMEDOUT;
258	}
259
260	if (temp & 0x10) {
261		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
262		result = -ENXIO;
263	}
264
265	if (temp & 0x20) {
266		dev_err(&adap->dev, "Bus collision! SMBus may be locked until "
267			"next hard reset (or not...)\n");
268		/* Clock stops and slave is stuck in mid-transmission */
269		result = -EIO;
270	}
271
272	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
273	if (temp != 0x00) {
274		sis5595_write(SMB_STS_LO, temp & 0xff);
275		sis5595_write(SMB_STS_HI, temp >> 8);
276	}
277
278	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
279	if (temp != 0x00)
280		dev_dbg(&adap->dev, "Failed reset at end of transaction (%02x)\n", temp);
281
282	return result;
283}
284
285/* Return negative errno on error. */
286static s32 sis5595_access(struct i2c_adapter *adap, u16 addr,
287			  unsigned short flags, char read_write,
288			  u8 command, int size, union i2c_smbus_data *data)
289{
290	int status;
291
292	switch (size) {
293	case I2C_SMBUS_QUICK:
294		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
295		size = SIS5595_QUICK;
296		break;
297	case I2C_SMBUS_BYTE:
298		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
299		if (read_write == I2C_SMBUS_WRITE)
300			sis5595_write(SMB_CMD, command);
301		size = SIS5595_BYTE;
302		break;
303	case I2C_SMBUS_BYTE_DATA:
304		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
305		sis5595_write(SMB_CMD, command);
306		if (read_write == I2C_SMBUS_WRITE)
307			sis5595_write(SMB_BYTE, data->byte);
308		size = SIS5595_BYTE_DATA;
309		break;
310	case I2C_SMBUS_PROC_CALL:
311	case I2C_SMBUS_WORD_DATA:
312		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
313		sis5595_write(SMB_CMD, command);
314		if (read_write == I2C_SMBUS_WRITE) {
315			sis5595_write(SMB_BYTE, data->word & 0xff);
316			sis5595_write(SMB_BYTE + 1,
317				      (data->word & 0xff00) >> 8);
318		}
319		size = (size == I2C_SMBUS_PROC_CALL) ? SIS5595_PROC_CALL : SIS5595_WORD_DATA;
320		break;
321	default:
322		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
323		return -EOPNOTSUPP;
324	}
325
326	sis5595_write(SMB_CTL_LO, ((size & 0x0E)));
327
328	status = sis5595_transaction(adap);
329	if (status)
330		return status;
331
332	if ((size != SIS5595_PROC_CALL) &&
333	    ((read_write == I2C_SMBUS_WRITE) || (size == SIS5595_QUICK)))
334		return 0;
335
336
337	switch (size) {
338	case SIS5595_BYTE:
339	case SIS5595_BYTE_DATA:
340		data->byte = sis5595_read(SMB_BYTE);
341		break;
342	case SIS5595_WORD_DATA:
343	case SIS5595_PROC_CALL:
344		data->word = sis5595_read(SMB_BYTE) + (sis5595_read(SMB_BYTE + 1) << 8);
345		break;
346	}
347	return 0;
348}
349
350static u32 sis5595_func(struct i2c_adapter *adapter)
351{
352	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
353	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
354	    I2C_FUNC_SMBUS_PROC_CALL;
355}
356
357static const struct i2c_algorithm smbus_algorithm = {
358	.smbus_xfer	= sis5595_access,
359	.functionality	= sis5595_func,
360};
361
362static struct i2c_adapter sis5595_adapter = {
363	.owner		= THIS_MODULE,
364	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
365	.algo		= &smbus_algorithm,
366};
367
368static const struct pci_device_id sis5595_ids[] = {
369	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
370	{ 0, }
371};
372
373MODULE_DEVICE_TABLE (pci, sis5595_ids);
374
375static int sis5595_probe(struct pci_dev *dev, const struct pci_device_id *id)
376{
377	int err;
378
379	if (sis5595_setup(dev)) {
380		dev_err(&dev->dev, "SIS5595 not detected, module not inserted.\n");
381		return -ENODEV;
382	}
383
384	/* set up the sysfs linkage to our parent device */
385	sis5595_adapter.dev.parent = &dev->dev;
386
387	snprintf(sis5595_adapter.name, sizeof(sis5595_adapter.name),
388		 "SMBus SIS5595 adapter at %04x", sis5595_base + SMB_INDEX);
389	err = i2c_add_adapter(&sis5595_adapter);
390	if (err) {
391		release_region(sis5595_base + SMB_INDEX, 2);
392		return err;
393	}
394
395	/* Always return failure here.  This is to allow other drivers to bind
396	 * to this pci device.  We don't really want to have control over the
397	 * pci device, we only wanted to read as few register values from it.
398	 */
399	sis5595_pdev =  pci_dev_get(dev);
400	return -ENODEV;
401}
402
403static struct pci_driver sis5595_driver = {
404	.name		= "sis5595_smbus",
405	.id_table	= sis5595_ids,
406	.probe		= sis5595_probe,
407};
408
409static int __init i2c_sis5595_init(void)
410{
411	return pci_register_driver(&sis5595_driver);
412}
413
414static void __exit i2c_sis5595_exit(void)
415{
416	pci_unregister_driver(&sis5595_driver);
417	if (sis5595_pdev) {
418		i2c_del_adapter(&sis5595_adapter);
419		release_region(sis5595_base + SMB_INDEX, 2);
420		pci_dev_put(sis5595_pdev);
421		sis5595_pdev = NULL;
422	}
423}
424
425MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
426MODULE_DESCRIPTION("SIS5595 SMBus driver");
427MODULE_LICENSE("GPL");
428
429module_init(i2c_sis5595_init);
430module_exit(i2c_sis5595_exit);
431