xref: /openbmc/linux/drivers/i2c/busses/i2c-amd756.c (revision 87c2ce3b)
1 /*
2     amd756.c - Part of lm_sensors, Linux kernel modules for hardware
3               monitoring
4 
5     Copyright (c) 1999-2002 Merlin Hughes <merlin@merlin.org>
6 
7     Shamelessly ripped from i2c-piix4.c:
8 
9     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
10     Philip Edelbrock <phil@netroedge.com>
11 
12     This program is free software; you can redistribute it and/or modify
13     it under the terms of the GNU General Public License as published by
14     the Free Software Foundation; either version 2 of the License, or
15     (at your option) any later version.
16 
17     This program is distributed in the hope that it will be useful,
18     but WITHOUT ANY WARRANTY; without even the implied warranty of
19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20     GNU General Public License for more details.
21 
22     You should have received a copy of the GNU General Public License
23     along with this program; if not, write to the Free Software
24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26 
27 /*
28     2002-04-08: Added nForce support. (Csaba Halasz)
29     2002-10-03: Fixed nForce PnP I/O port. (Michael Steil)
30     2002-12-28: Rewritten into something that resembles a Linux driver (hch)
31     2003-11-29: Added back AMD8111 removed by the previous rewrite.
32                 (Philip Pokorny)
33 */
34 
35 /*
36    Supports AMD756, AMD766, AMD768, AMD8111 and nVidia nForce
37    Note: we assume there can only be one device, with one SMBus interface.
38 */
39 
40 #include <linux/module.h>
41 #include <linux/pci.h>
42 #include <linux/kernel.h>
43 #include <linux/delay.h>
44 #include <linux/stddef.h>
45 #include <linux/sched.h>
46 #include <linux/ioport.h>
47 #include <linux/i2c.h>
48 #include <linux/init.h>
49 #include <asm/io.h>
50 
51 /* AMD756 SMBus address offsets */
52 #define SMB_ADDR_OFFSET		0xE0
53 #define SMB_IOSIZE		16
54 #define SMB_GLOBAL_STATUS	(0x0 + amd756_ioport)
55 #define SMB_GLOBAL_ENABLE	(0x2 + amd756_ioport)
56 #define SMB_HOST_ADDRESS	(0x4 + amd756_ioport)
57 #define SMB_HOST_DATA		(0x6 + amd756_ioport)
58 #define SMB_HOST_COMMAND	(0x8 + amd756_ioport)
59 #define SMB_HOST_BLOCK_DATA	(0x9 + amd756_ioport)
60 #define SMB_HAS_DATA		(0xA + amd756_ioport)
61 #define SMB_HAS_DEVICE_ADDRESS	(0xC + amd756_ioport)
62 #define SMB_HAS_HOST_ADDRESS	(0xE + amd756_ioport)
63 #define SMB_SNOOP_ADDRESS	(0xF + amd756_ioport)
64 
65 /* PCI Address Constants */
66 
67 /* address of I/O space */
68 #define SMBBA		0x058		/* mh */
69 #define SMBBANFORCE	0x014
70 
71 /* general configuration */
72 #define SMBGCFG		0x041		/* mh */
73 
74 /* silicon revision code */
75 #define SMBREV		0x008
76 
77 /* Other settings */
78 #define MAX_TIMEOUT	500
79 
80 /* AMD756 constants */
81 #define AMD756_QUICK		0x00
82 #define AMD756_BYTE		0x01
83 #define AMD756_BYTE_DATA	0x02
84 #define AMD756_WORD_DATA	0x03
85 #define AMD756_PROCESS_CALL	0x04
86 #define AMD756_BLOCK_DATA	0x05
87 
88 static struct pci_driver amd756_driver;
89 static unsigned short amd756_ioport;
90 
91 /*
92   SMBUS event = I/O 28-29 bit 11
93      see E0 for the status bits and enabled in E2
94 
95 */
96 #define GS_ABRT_STS	(1 << 0)
97 #define GS_COL_STS	(1 << 1)
98 #define GS_PRERR_STS	(1 << 2)
99 #define GS_HST_STS	(1 << 3)
100 #define GS_HCYC_STS	(1 << 4)
101 #define GS_TO_STS	(1 << 5)
102 #define GS_SMB_STS	(1 << 11)
103 
104 #define GS_CLEAR_STS	(GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
105 			 GS_HCYC_STS | GS_TO_STS )
106 
107 #define GE_CYC_TYPE_MASK	(7)
108 #define GE_HOST_STC		(1 << 3)
109 #define GE_ABORT		(1 << 5)
110 
111 
112 static int amd756_transaction(struct i2c_adapter *adap)
113 {
114 	int temp;
115 	int result = 0;
116 	int timeout = 0;
117 
118 	dev_dbg(&adap->dev, "Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, "
119 		"DAT=%04x\n", inw_p(SMB_GLOBAL_STATUS),
120 		inw_p(SMB_GLOBAL_ENABLE), inw_p(SMB_HOST_ADDRESS),
121 		inb_p(SMB_HOST_DATA));
122 
123 	/* Make sure the SMBus host is ready to start transmitting */
124 	if ((temp = inw_p(SMB_GLOBAL_STATUS)) & (GS_HST_STS | GS_SMB_STS)) {
125 		dev_dbg(&adap->dev, "SMBus busy (%04x). Waiting...\n", temp);
126 		do {
127 			msleep(1);
128 			temp = inw_p(SMB_GLOBAL_STATUS);
129 		} while ((temp & (GS_HST_STS | GS_SMB_STS)) &&
130 		         (timeout++ < MAX_TIMEOUT));
131 		/* If the SMBus is still busy, we give up */
132 		if (timeout >= MAX_TIMEOUT) {
133 			dev_dbg(&adap->dev, "Busy wait timeout (%04x)\n", temp);
134 			goto abort;
135 		}
136 		timeout = 0;
137 	}
138 
139 	/* start the transaction by setting the start bit */
140 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);
141 
142 	/* We will always wait for a fraction of a second! */
143 	do {
144 		msleep(1);
145 		temp = inw_p(SMB_GLOBAL_STATUS);
146 	} while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));
147 
148 	/* If the SMBus is still busy, we give up */
149 	if (timeout >= MAX_TIMEOUT) {
150 		dev_dbg(&adap->dev, "Completion timeout!\n");
151 		goto abort;
152 	}
153 
154 	if (temp & GS_PRERR_STS) {
155 		result = -1;
156 		dev_dbg(&adap->dev, "SMBus Protocol error (no response)!\n");
157 	}
158 
159 	if (temp & GS_COL_STS) {
160 		result = -1;
161 		dev_warn(&adap->dev, "SMBus collision!\n");
162 	}
163 
164 	if (temp & GS_TO_STS) {
165 		result = -1;
166 		dev_dbg(&adap->dev, "SMBus protocol timeout!\n");
167 	}
168 
169 	if (temp & GS_HCYC_STS)
170 		dev_dbg(&adap->dev, "SMBus protocol success!\n");
171 
172 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
173 
174 #ifdef DEBUG
175 	if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
176 		dev_dbg(&adap->dev,
177 			"Failed reset at end of transaction (%04x)\n", temp);
178 	}
179 #endif
180 
181 	dev_dbg(&adap->dev,
182 		"Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
183 		inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
184 		inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
185 
186 	return result;
187 
188  abort:
189 	dev_warn(&adap->dev, "Sending abort\n");
190 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_ABORT, SMB_GLOBAL_ENABLE);
191 	msleep(100);
192 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
193 	return -1;
194 }
195 
196 /* Return -1 on error. */
197 static s32 amd756_access(struct i2c_adapter * adap, u16 addr,
198 		  unsigned short flags, char read_write,
199 		  u8 command, int size, union i2c_smbus_data * data)
200 {
201 	int i, len;
202 
203 	/** TODO: Should I supporte the 10-bit transfers? */
204 	switch (size) {
205 	case I2C_SMBUS_PROC_CALL:
206 		dev_dbg(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
207 		/* TODO: Well... It is supported, I'm just not sure what to do here... */
208 		return -1;
209 	case I2C_SMBUS_QUICK:
210 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
211 		       SMB_HOST_ADDRESS);
212 		size = AMD756_QUICK;
213 		break;
214 	case I2C_SMBUS_BYTE:
215 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
216 		       SMB_HOST_ADDRESS);
217 		if (read_write == I2C_SMBUS_WRITE)
218 			outb_p(command, SMB_HOST_DATA);
219 		size = AMD756_BYTE;
220 		break;
221 	case I2C_SMBUS_BYTE_DATA:
222 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
223 		       SMB_HOST_ADDRESS);
224 		outb_p(command, SMB_HOST_COMMAND);
225 		if (read_write == I2C_SMBUS_WRITE)
226 			outw_p(data->byte, SMB_HOST_DATA);
227 		size = AMD756_BYTE_DATA;
228 		break;
229 	case I2C_SMBUS_WORD_DATA:
230 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
231 		       SMB_HOST_ADDRESS);
232 		outb_p(command, SMB_HOST_COMMAND);
233 		if (read_write == I2C_SMBUS_WRITE)
234 			outw_p(data->word, SMB_HOST_DATA);	/* TODO: endian???? */
235 		size = AMD756_WORD_DATA;
236 		break;
237 	case I2C_SMBUS_BLOCK_DATA:
238 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
239 		       SMB_HOST_ADDRESS);
240 		outb_p(command, SMB_HOST_COMMAND);
241 		if (read_write == I2C_SMBUS_WRITE) {
242 			len = data->block[0];
243 			if (len < 0)
244 				len = 0;
245 			if (len > 32)
246 				len = 32;
247 			outw_p(len, SMB_HOST_DATA);
248 			/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
249 			for (i = 1; i <= len; i++)
250 				outb_p(data->block[i],
251 				       SMB_HOST_BLOCK_DATA);
252 		}
253 		size = AMD756_BLOCK_DATA;
254 		break;
255 	}
256 
257 	/* How about enabling interrupts... */
258 	outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);
259 
260 	if (amd756_transaction(adap))	/* Error in transaction */
261 		return -1;
262 
263 	if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
264 		return 0;
265 
266 
267 	switch (size) {
268 	case AMD756_BYTE:
269 		data->byte = inw_p(SMB_HOST_DATA);
270 		break;
271 	case AMD756_BYTE_DATA:
272 		data->byte = inw_p(SMB_HOST_DATA);
273 		break;
274 	case AMD756_WORD_DATA:
275 		data->word = inw_p(SMB_HOST_DATA);	/* TODO: endian???? */
276 		break;
277 	case AMD756_BLOCK_DATA:
278 		data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;
279 		if(data->block[0] > 32)
280 			data->block[0] = 32;
281 		/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
282 		for (i = 1; i <= data->block[0]; i++)
283 			data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
284 		break;
285 	}
286 
287 	return 0;
288 }
289 
290 static u32 amd756_func(struct i2c_adapter *adapter)
291 {
292 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
293 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
294 	    I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL;
295 }
296 
297 static struct i2c_algorithm smbus_algorithm = {
298 	.smbus_xfer	= amd756_access,
299 	.functionality	= amd756_func,
300 };
301 
302 struct i2c_adapter amd756_smbus = {
303 	.owner		= THIS_MODULE,
304 	.class          = I2C_CLASS_HWMON,
305 	.algo		= &smbus_algorithm,
306 };
307 
308 enum chiptype { AMD756, AMD766, AMD768, NFORCE, AMD8111 };
309 static const char* chipname[] = {
310 	"AMD756", "AMD766", "AMD768",
311 	"nVidia nForce", "AMD8111",
312 };
313 
314 static struct pci_device_id amd756_ids[] = {
315 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
316 	  .driver_data = AMD756 },
317 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),
318 	  .driver_data = AMD766 },
319 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_OPUS_7443),
320 	  .driver_data = AMD768 },
321 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS),
322 	  .driver_data = AMD8111 },
323 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_SMBUS),
324 	  .driver_data = NFORCE },
325 	{ 0, }
326 };
327 
328 MODULE_DEVICE_TABLE (pci, amd756_ids);
329 
330 static int __devinit amd756_probe(struct pci_dev *pdev,
331 				  const struct pci_device_id *id)
332 {
333 	int nforce = (id->driver_data == NFORCE);
334 	int error;
335 	u8 temp;
336 
337 	if (amd756_ioport) {
338 		dev_err(&pdev->dev, "Only one device supported "
339 		       "(you have a strange motherboard, btw)\n");
340 		return -ENODEV;
341 	}
342 
343 	if (nforce) {
344 		if (PCI_FUNC(pdev->devfn) != 1)
345 			return -ENODEV;
346 
347 		pci_read_config_word(pdev, SMBBANFORCE, &amd756_ioport);
348 		amd756_ioport &= 0xfffc;
349 	} else { /* amd */
350 		if (PCI_FUNC(pdev->devfn) != 3)
351 			return -ENODEV;
352 
353 		pci_read_config_byte(pdev, SMBGCFG, &temp);
354 		if ((temp & 128) == 0) {
355 			dev_err(&pdev->dev,
356 				"Error: SMBus controller I/O not enabled!\n");
357 			return -ENODEV;
358 		}
359 
360 		/* Determine the address of the SMBus areas */
361 		/* Technically it is a dword but... */
362 		pci_read_config_word(pdev, SMBBA, &amd756_ioport);
363 		amd756_ioport &= 0xff00;
364 		amd756_ioport += SMB_ADDR_OFFSET;
365 	}
366 
367 	if (!request_region(amd756_ioport, SMB_IOSIZE, amd756_driver.name)) {
368 		dev_err(&pdev->dev, "SMB region 0x%x already in use!\n",
369 			amd756_ioport);
370 		return -ENODEV;
371 	}
372 
373 	pci_read_config_byte(pdev, SMBREV, &temp);
374 	dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
375 	dev_dbg(&pdev->dev, "AMD756_smba = 0x%X\n", amd756_ioport);
376 
377 	/* set up the driverfs linkage to our parent device */
378 	amd756_smbus.dev.parent = &pdev->dev;
379 
380 	sprintf(amd756_smbus.name, "SMBus %s adapter at %04x",
381 		chipname[id->driver_data], amd756_ioport);
382 
383 	error = i2c_add_adapter(&amd756_smbus);
384 	if (error) {
385 		dev_err(&pdev->dev,
386 			"Adapter registration failed, module not inserted\n");
387 		goto out_err;
388 	}
389 
390 	return 0;
391 
392  out_err:
393 	release_region(amd756_ioport, SMB_IOSIZE);
394 	return error;
395 }
396 
397 static void __devexit amd756_remove(struct pci_dev *dev)
398 {
399 	i2c_del_adapter(&amd756_smbus);
400 	release_region(amd756_ioport, SMB_IOSIZE);
401 }
402 
403 static struct pci_driver amd756_driver = {
404 	.name		= "amd756_smbus",
405 	.id_table	= amd756_ids,
406 	.probe		= amd756_probe,
407 	.remove		= __devexit_p(amd756_remove),
408 };
409 
410 static int __init amd756_init(void)
411 {
412 	return pci_register_driver(&amd756_driver);
413 }
414 
415 static void __exit amd756_exit(void)
416 {
417 	pci_unregister_driver(&amd756_driver);
418 }
419 
420 MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
421 MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
422 MODULE_LICENSE("GPL");
423 
424 EXPORT_SYMBOL(amd756_smbus);
425 
426 module_init(amd756_init)
427 module_exit(amd756_exit)
428