xref: /openbmc/linux/drivers/i2c/busses/i2c-sis5595.c (revision 3401b2ff)
1 /*
2     sis5595.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
5     Philip Edelbrock <phil@netroedge.com>
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 
22 /* Note: we assume there can only be one SIS5595 with one SMBus interface */
23 
24 /*
25    Note: all have mfr. ID 0x1039.
26    SUPPORTED		PCI ID
27 	5595		0008
28 
29    Note: these chips contain a 0008 device which is incompatible with the
30          5595. We recognize these by the presence of the listed
31          "blacklist" PCI ID and refuse to load.
32 
33    NOT SUPPORTED	PCI ID		BLACKLIST PCI ID
34 	 540		0008		0540
35 	 550		0008		0550
36 	5513		0008		5511
37 	5581		0008		5597
38 	5582		0008		5597
39 	5597		0008		5597
40 	5598		0008		5597/5598
41 	 630		0008		0630
42 	 645		0008		0645
43 	 646		0008		0646
44 	 648		0008		0648
45 	 650		0008		0650
46 	 651		0008		0651
47 	 730		0008		0730
48 	 735		0008		0735
49 	 745		0008		0745
50 	 746		0008		0746
51 */
52 
53 /* TO DO:
54  * Add Block Transfers (ugly, but supported by the adapter)
55  * Add adapter resets
56  */
57 
58 #include <linux/kernel.h>
59 #include <linux/module.h>
60 #include <linux/delay.h>
61 #include <linux/pci.h>
62 #include <linux/ioport.h>
63 #include <linux/init.h>
64 #include <linux/i2c.h>
65 #include <asm/io.h>
66 
67 static int blacklist[] = {
68 	PCI_DEVICE_ID_SI_540,
69 	PCI_DEVICE_ID_SI_550,
70 	PCI_DEVICE_ID_SI_630,
71 	PCI_DEVICE_ID_SI_645,
72 	PCI_DEVICE_ID_SI_646,
73 	PCI_DEVICE_ID_SI_648,
74 	PCI_DEVICE_ID_SI_650,
75 	PCI_DEVICE_ID_SI_651,
76 	PCI_DEVICE_ID_SI_730,
77 	PCI_DEVICE_ID_SI_735,
78 	PCI_DEVICE_ID_SI_745,
79 	PCI_DEVICE_ID_SI_746,
80 	PCI_DEVICE_ID_SI_5511,	/* 5513 chip has the 0008 device but that ID
81 				   shows up in other chips so we use the 5511
82 				   ID for recognition */
83 	PCI_DEVICE_ID_SI_5597,
84 	PCI_DEVICE_ID_SI_5598,
85 	0,			/* terminates the list */
86 };
87 
88 /* Length of ISA address segment */
89 #define SIS5595_EXTENT		8
90 /* SIS5595 SMBus registers */
91 #define SMB_STS_LO		0x00
92 #define SMB_STS_HI		0x01
93 #define SMB_CTL_LO		0x02
94 #define SMB_CTL_HI		0x03
95 #define SMB_ADDR		0x04
96 #define SMB_CMD			0x05
97 #define SMB_PCNT		0x06
98 #define SMB_CNT			0x07
99 #define SMB_BYTE		0x08
100 #define SMB_DEV			0x10
101 #define SMB_DB0			0x11
102 #define SMB_DB1			0x12
103 #define SMB_HAA			0x13
104 
105 /* PCI Address Constants */
106 #define SMB_INDEX		0x38
107 #define SMB_DAT			0x39
108 #define SIS5595_ENABLE_REG	0x40
109 #define ACPI_BASE		0x90
110 
111 /* Other settings */
112 #define MAX_TIMEOUT		500
113 
114 /* SIS5595 constants */
115 #define SIS5595_QUICK		0x00
116 #define SIS5595_BYTE		0x02
117 #define SIS5595_BYTE_DATA	0x04
118 #define SIS5595_WORD_DATA	0x06
119 #define SIS5595_PROC_CALL	0x08
120 #define SIS5595_BLOCK_DATA	0x0A
121 
122 /* insmod parameters */
123 
124 /* If force_addr is set to anything different from 0, we forcibly enable
125    the device at the given address. */
126 static u16 force_addr;
127 module_param(force_addr, ushort, 0);
128 MODULE_PARM_DESC(force_addr, "Initialize the base address of the i2c controller");
129 
130 static struct pci_driver sis5595_driver;
131 static unsigned short sis5595_base;
132 static struct pci_dev *sis5595_pdev;
133 
134 static u8 sis5595_read(u8 reg)
135 {
136 	outb(reg, sis5595_base + SMB_INDEX);
137 	return inb(sis5595_base + SMB_DAT);
138 }
139 
140 static void sis5595_write(u8 reg, u8 data)
141 {
142 	outb(reg, sis5595_base + SMB_INDEX);
143 	outb(data, sis5595_base + SMB_DAT);
144 }
145 
146 static int sis5595_setup(struct pci_dev *SIS5595_dev)
147 {
148 	u16 a;
149 	u8 val;
150 	int *i;
151 	int retval = -ENODEV;
152 
153 	/* Look for imposters */
154 	for (i = blacklist; *i != 0; i++) {
155 		struct pci_dev *dev;
156 		dev = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
157 		if (dev) {
158 			dev_err(&SIS5595_dev->dev, "Looked for SIS5595 but found unsupported device %.4x\n", *i);
159 			pci_dev_put(dev);
160 			return -ENODEV;
161 		}
162 	}
163 
164 	/* Determine the address of the SMBus areas */
165 	pci_read_config_word(SIS5595_dev, ACPI_BASE, &sis5595_base);
166 	if (sis5595_base == 0 && force_addr == 0) {
167 		dev_err(&SIS5595_dev->dev, "ACPI base address uninitialized - upgrade BIOS or use force_addr=0xaddr\n");
168 		return -ENODEV;
169 	}
170 
171 	if (force_addr)
172 		sis5595_base = force_addr & ~(SIS5595_EXTENT - 1);
173 	dev_dbg(&SIS5595_dev->dev, "ACPI Base address: %04x\n", sis5595_base);
174 
175 	/* NB: We grab just the two SMBus registers here, but this may still
176 	 * interfere with ACPI :-(  */
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 
220 error:
221 	release_region(sis5595_base + SMB_INDEX, 2);
222 	return retval;
223 }
224 
225 static 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. */
286 static 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 
350 static 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 
357 static const struct i2c_algorithm smbus_algorithm = {
358 	.smbus_xfer	= sis5595_access,
359 	.functionality	= sis5595_func,
360 };
361 
362 static struct i2c_adapter sis5595_adapter = {
363 	.owner		= THIS_MODULE,
364 	.id		= I2C_HW_SMBUS_SIS5595,
365 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
366 	.algo		= &smbus_algorithm,
367 };
368 
369 static struct pci_device_id sis5595_ids[] __devinitdata = {
370 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
371 	{ 0, }
372 };
373 
374 MODULE_DEVICE_TABLE (pci, sis5595_ids);
375 
376 static int __devinit sis5595_probe(struct pci_dev *dev, const struct pci_device_id *id)
377 {
378 	int err;
379 
380 	if (sis5595_setup(dev)) {
381 		dev_err(&dev->dev, "SIS5595 not detected, module not inserted.\n");
382 		return -ENODEV;
383 	}
384 
385 	/* set up the sysfs linkage to our parent device */
386 	sis5595_adapter.dev.parent = &dev->dev;
387 
388 	sprintf(sis5595_adapter.name, "SMBus SIS5595 adapter at %04x",
389 		sis5595_base + SMB_INDEX);
390 	err = i2c_add_adapter(&sis5595_adapter);
391 	if (err) {
392 		release_region(sis5595_base + SMB_INDEX, 2);
393 		return err;
394 	}
395 
396 	/* Always return failure here.  This is to allow other drivers to bind
397 	 * to this pci device.  We don't really want to have control over the
398 	 * pci device, we only wanted to read as few register values from it.
399 	 */
400 	sis5595_pdev =  pci_dev_get(dev);
401 	return -ENODEV;
402 }
403 
404 static struct pci_driver sis5595_driver = {
405 	.name		= "sis5595_smbus",
406 	.id_table	= sis5595_ids,
407 	.probe		= sis5595_probe,
408 };
409 
410 static int __init i2c_sis5595_init(void)
411 {
412 	return pci_register_driver(&sis5595_driver);
413 }
414 
415 static void __exit i2c_sis5595_exit(void)
416 {
417 	pci_unregister_driver(&sis5595_driver);
418 	if (sis5595_pdev) {
419 		i2c_del_adapter(&sis5595_adapter);
420 		release_region(sis5595_base + SMB_INDEX, 2);
421 		pci_dev_put(sis5595_pdev);
422 		sis5595_pdev = NULL;
423 	}
424 }
425 
426 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
427 MODULE_DESCRIPTION("SIS5595 SMBus driver");
428 MODULE_LICENSE("GPL");
429 
430 module_init(i2c_sis5595_init);
431 module_exit(i2c_sis5595_exit);
432