xref: /openbmc/linux/drivers/i2c/busses/i2c-amd756.c (revision b34e08d5)
1 /*
2     Copyright (c) 1999-2002 Merlin Hughes <merlin@merlin.org>
3 
4     Shamelessly ripped from i2c-piix4.c:
5 
6     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
7     Philip Edelbrock <phil@netroedge.com>
8 
9     This program is free software; you can redistribute it and/or modify
10     it under the terms of the GNU General Public License as published by
11     the Free Software Foundation; either version 2 of the License, or
12     (at your option) any later version.
13 
14     This program is distributed in the hope that it will be useful,
15     but WITHOUT ANY WARRANTY; without even the implied warranty of
16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17     GNU General Public License for more details.
18 
19     You should have received a copy of the GNU General Public License
20     along with this program; if not, write to the Free Software
21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23 
24 /*
25     2002-04-08: Added nForce support. (Csaba Halasz)
26     2002-10-03: Fixed nForce PnP I/O port. (Michael Steil)
27     2002-12-28: Rewritten into something that resembles a Linux driver (hch)
28     2003-11-29: Added back AMD8111 removed by the previous rewrite.
29                 (Philip Pokorny)
30 */
31 
32 /*
33    Supports AMD756, AMD766, AMD768, AMD8111 and nVidia nForce
34    Note: we assume there can only be one device, with one SMBus interface.
35 */
36 
37 #include <linux/module.h>
38 #include <linux/pci.h>
39 #include <linux/kernel.h>
40 #include <linux/delay.h>
41 #include <linux/stddef.h>
42 #include <linux/ioport.h>
43 #include <linux/i2c.h>
44 #include <linux/acpi.h>
45 #include <linux/io.h>
46 
47 /* AMD756 SMBus address offsets */
48 #define SMB_ADDR_OFFSET		0xE0
49 #define SMB_IOSIZE		16
50 #define SMB_GLOBAL_STATUS	(0x0 + amd756_ioport)
51 #define SMB_GLOBAL_ENABLE	(0x2 + amd756_ioport)
52 #define SMB_HOST_ADDRESS	(0x4 + amd756_ioport)
53 #define SMB_HOST_DATA		(0x6 + amd756_ioport)
54 #define SMB_HOST_COMMAND	(0x8 + amd756_ioport)
55 #define SMB_HOST_BLOCK_DATA	(0x9 + amd756_ioport)
56 #define SMB_HAS_DATA		(0xA + amd756_ioport)
57 #define SMB_HAS_DEVICE_ADDRESS	(0xC + amd756_ioport)
58 #define SMB_HAS_HOST_ADDRESS	(0xE + amd756_ioport)
59 #define SMB_SNOOP_ADDRESS	(0xF + amd756_ioport)
60 
61 /* PCI Address Constants */
62 
63 /* address of I/O space */
64 #define SMBBA		0x058		/* mh */
65 #define SMBBANFORCE	0x014
66 
67 /* general configuration */
68 #define SMBGCFG		0x041		/* mh */
69 
70 /* silicon revision code */
71 #define SMBREV		0x008
72 
73 /* Other settings */
74 #define MAX_TIMEOUT	500
75 
76 /* AMD756 constants */
77 #define AMD756_QUICK		0x00
78 #define AMD756_BYTE		0x01
79 #define AMD756_BYTE_DATA	0x02
80 #define AMD756_WORD_DATA	0x03
81 #define AMD756_PROCESS_CALL	0x04
82 #define AMD756_BLOCK_DATA	0x05
83 
84 static struct pci_driver amd756_driver;
85 static unsigned short amd756_ioport;
86 
87 /*
88   SMBUS event = I/O 28-29 bit 11
89      see E0 for the status bits and enabled in E2
90 
91 */
92 #define GS_ABRT_STS	(1 << 0)
93 #define GS_COL_STS	(1 << 1)
94 #define GS_PRERR_STS	(1 << 2)
95 #define GS_HST_STS	(1 << 3)
96 #define GS_HCYC_STS	(1 << 4)
97 #define GS_TO_STS	(1 << 5)
98 #define GS_SMB_STS	(1 << 11)
99 
100 #define GS_CLEAR_STS	(GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
101 			 GS_HCYC_STS | GS_TO_STS )
102 
103 #define GE_CYC_TYPE_MASK	(7)
104 #define GE_HOST_STC		(1 << 3)
105 #define GE_ABORT		(1 << 5)
106 
107 
108 static int amd756_transaction(struct i2c_adapter *adap)
109 {
110 	int temp;
111 	int result = 0;
112 	int timeout = 0;
113 
114 	dev_dbg(&adap->dev, "Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, "
115 		"DAT=%04x\n", inw_p(SMB_GLOBAL_STATUS),
116 		inw_p(SMB_GLOBAL_ENABLE), inw_p(SMB_HOST_ADDRESS),
117 		inb_p(SMB_HOST_DATA));
118 
119 	/* Make sure the SMBus host is ready to start transmitting */
120 	if ((temp = inw_p(SMB_GLOBAL_STATUS)) & (GS_HST_STS | GS_SMB_STS)) {
121 		dev_dbg(&adap->dev, "SMBus busy (%04x). Waiting...\n", temp);
122 		do {
123 			msleep(1);
124 			temp = inw_p(SMB_GLOBAL_STATUS);
125 		} while ((temp & (GS_HST_STS | GS_SMB_STS)) &&
126 		         (timeout++ < MAX_TIMEOUT));
127 		/* If the SMBus is still busy, we give up */
128 		if (timeout > MAX_TIMEOUT) {
129 			dev_dbg(&adap->dev, "Busy wait timeout (%04x)\n", temp);
130 			goto abort;
131 		}
132 		timeout = 0;
133 	}
134 
135 	/* start the transaction by setting the start bit */
136 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);
137 
138 	/* We will always wait for a fraction of a second! */
139 	do {
140 		msleep(1);
141 		temp = inw_p(SMB_GLOBAL_STATUS);
142 	} while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));
143 
144 	/* If the SMBus is still busy, we give up */
145 	if (timeout > MAX_TIMEOUT) {
146 		dev_dbg(&adap->dev, "Completion timeout!\n");
147 		goto abort;
148 	}
149 
150 	if (temp & GS_PRERR_STS) {
151 		result = -ENXIO;
152 		dev_dbg(&adap->dev, "SMBus Protocol error (no response)!\n");
153 	}
154 
155 	if (temp & GS_COL_STS) {
156 		result = -EIO;
157 		dev_warn(&adap->dev, "SMBus collision!\n");
158 	}
159 
160 	if (temp & GS_TO_STS) {
161 		result = -ETIMEDOUT;
162 		dev_dbg(&adap->dev, "SMBus protocol timeout!\n");
163 	}
164 
165 	if (temp & GS_HCYC_STS)
166 		dev_dbg(&adap->dev, "SMBus protocol success!\n");
167 
168 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
169 
170 #ifdef DEBUG
171 	if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
172 		dev_dbg(&adap->dev,
173 			"Failed reset at end of transaction (%04x)\n", temp);
174 	}
175 #endif
176 
177 	dev_dbg(&adap->dev,
178 		"Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
179 		inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
180 		inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
181 
182 	return result;
183 
184  abort:
185 	dev_warn(&adap->dev, "Sending abort\n");
186 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_ABORT, SMB_GLOBAL_ENABLE);
187 	msleep(100);
188 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
189 	return -EIO;
190 }
191 
192 /* Return negative errno on error. */
193 static s32 amd756_access(struct i2c_adapter * adap, u16 addr,
194 		  unsigned short flags, char read_write,
195 		  u8 command, int size, union i2c_smbus_data * data)
196 {
197 	int i, len;
198 	int status;
199 
200 	switch (size) {
201 	case I2C_SMBUS_QUICK:
202 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
203 		       SMB_HOST_ADDRESS);
204 		size = AMD756_QUICK;
205 		break;
206 	case I2C_SMBUS_BYTE:
207 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
208 		       SMB_HOST_ADDRESS);
209 		if (read_write == I2C_SMBUS_WRITE)
210 			outb_p(command, SMB_HOST_DATA);
211 		size = AMD756_BYTE;
212 		break;
213 	case I2C_SMBUS_BYTE_DATA:
214 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
215 		       SMB_HOST_ADDRESS);
216 		outb_p(command, SMB_HOST_COMMAND);
217 		if (read_write == I2C_SMBUS_WRITE)
218 			outw_p(data->byte, SMB_HOST_DATA);
219 		size = AMD756_BYTE_DATA;
220 		break;
221 	case I2C_SMBUS_WORD_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->word, SMB_HOST_DATA);	/* TODO: endian???? */
227 		size = AMD756_WORD_DATA;
228 		break;
229 	case I2C_SMBUS_BLOCK_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 			len = data->block[0];
235 			if (len < 0)
236 				len = 0;
237 			if (len > 32)
238 				len = 32;
239 			outw_p(len, SMB_HOST_DATA);
240 			/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
241 			for (i = 1; i <= len; i++)
242 				outb_p(data->block[i],
243 				       SMB_HOST_BLOCK_DATA);
244 		}
245 		size = AMD756_BLOCK_DATA;
246 		break;
247 	default:
248 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
249 		return -EOPNOTSUPP;
250 	}
251 
252 	/* How about enabling interrupts... */
253 	outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);
254 
255 	status = amd756_transaction(adap);
256 	if (status)
257 		return status;
258 
259 	if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
260 		return 0;
261 
262 
263 	switch (size) {
264 	case AMD756_BYTE:
265 		data->byte = inw_p(SMB_HOST_DATA);
266 		break;
267 	case AMD756_BYTE_DATA:
268 		data->byte = inw_p(SMB_HOST_DATA);
269 		break;
270 	case AMD756_WORD_DATA:
271 		data->word = inw_p(SMB_HOST_DATA);	/* TODO: endian???? */
272 		break;
273 	case AMD756_BLOCK_DATA:
274 		data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;
275 		if(data->block[0] > 32)
276 			data->block[0] = 32;
277 		/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
278 		for (i = 1; i <= data->block[0]; i++)
279 			data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
280 		break;
281 	}
282 
283 	return 0;
284 }
285 
286 static u32 amd756_func(struct i2c_adapter *adapter)
287 {
288 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
289 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
290 	    I2C_FUNC_SMBUS_BLOCK_DATA;
291 }
292 
293 static const struct i2c_algorithm smbus_algorithm = {
294 	.smbus_xfer	= amd756_access,
295 	.functionality	= amd756_func,
296 };
297 
298 struct i2c_adapter amd756_smbus = {
299 	.owner		= THIS_MODULE,
300 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
301 	.algo		= &smbus_algorithm,
302 };
303 
304 enum chiptype { AMD756, AMD766, AMD768, NFORCE, AMD8111 };
305 static const char* chipname[] = {
306 	"AMD756", "AMD766", "AMD768",
307 	"nVidia nForce", "AMD8111",
308 };
309 
310 static const struct pci_device_id amd756_ids[] = {
311 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
312 	  .driver_data = AMD756 },
313 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),
314 	  .driver_data = AMD766 },
315 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_OPUS_7443),
316 	  .driver_data = AMD768 },
317 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS),
318 	  .driver_data = AMD8111 },
319 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_SMBUS),
320 	  .driver_data = NFORCE },
321 	{ 0, }
322 };
323 
324 MODULE_DEVICE_TABLE (pci, amd756_ids);
325 
326 static int amd756_probe(struct pci_dev *pdev, const struct pci_device_id *id)
327 {
328 	int nforce = (id->driver_data == NFORCE);
329 	int error;
330 	u8 temp;
331 
332 	if (amd756_ioport) {
333 		dev_err(&pdev->dev, "Only one device supported "
334 		       "(you have a strange motherboard, btw)\n");
335 		return -ENODEV;
336 	}
337 
338 	if (nforce) {
339 		if (PCI_FUNC(pdev->devfn) != 1)
340 			return -ENODEV;
341 
342 		pci_read_config_word(pdev, SMBBANFORCE, &amd756_ioport);
343 		amd756_ioport &= 0xfffc;
344 	} else { /* amd */
345 		if (PCI_FUNC(pdev->devfn) != 3)
346 			return -ENODEV;
347 
348 		pci_read_config_byte(pdev, SMBGCFG, &temp);
349 		if ((temp & 128) == 0) {
350 			dev_err(&pdev->dev,
351 				"Error: SMBus controller I/O not enabled!\n");
352 			return -ENODEV;
353 		}
354 
355 		/* Determine the address of the SMBus areas */
356 		/* Technically it is a dword but... */
357 		pci_read_config_word(pdev, SMBBA, &amd756_ioport);
358 		amd756_ioport &= 0xff00;
359 		amd756_ioport += SMB_ADDR_OFFSET;
360 	}
361 
362 	error = acpi_check_region(amd756_ioport, SMB_IOSIZE,
363 				  amd756_driver.name);
364 	if (error)
365 		return -ENODEV;
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 sysfs linkage to our parent device */
378 	amd756_smbus.dev.parent = &pdev->dev;
379 
380 	snprintf(amd756_smbus.name, sizeof(amd756_smbus.name),
381 		 "SMBus %s adapter at %04x", chipname[id->driver_data],
382 		 amd756_ioport);
383 
384 	error = i2c_add_adapter(&amd756_smbus);
385 	if (error) {
386 		dev_err(&pdev->dev,
387 			"Adapter registration failed, module not inserted\n");
388 		goto out_err;
389 	}
390 
391 	return 0;
392 
393  out_err:
394 	release_region(amd756_ioport, SMB_IOSIZE);
395 	return error;
396 }
397 
398 static void amd756_remove(struct pci_dev *dev)
399 {
400 	i2c_del_adapter(&amd756_smbus);
401 	release_region(amd756_ioport, SMB_IOSIZE);
402 }
403 
404 static struct pci_driver amd756_driver = {
405 	.name		= "amd756_smbus",
406 	.id_table	= amd756_ids,
407 	.probe		= amd756_probe,
408 	.remove		= amd756_remove,
409 };
410 
411 module_pci_driver(amd756_driver);
412 
413 MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
414 MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
415 MODULE_LICENSE("GPL");
416 
417 EXPORT_SYMBOL(amd756_smbus);
418