xref: /openbmc/linux/drivers/i2c/busses/i2c-amd756.c (revision 82e6fdd6)
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 
20 /*
21     2002-04-08: Added nForce support. (Csaba Halasz)
22     2002-10-03: Fixed nForce PnP I/O port. (Michael Steil)
23     2002-12-28: Rewritten into something that resembles a Linux driver (hch)
24     2003-11-29: Added back AMD8111 removed by the previous rewrite.
25                 (Philip Pokorny)
26 */
27 
28 /*
29    Supports AMD756, AMD766, AMD768, AMD8111 and nVidia nForce
30    Note: we assume there can only be one device, with one SMBus interface.
31 */
32 
33 #include <linux/module.h>
34 #include <linux/pci.h>
35 #include <linux/kernel.h>
36 #include <linux/delay.h>
37 #include <linux/stddef.h>
38 #include <linux/ioport.h>
39 #include <linux/i2c.h>
40 #include <linux/acpi.h>
41 #include <linux/io.h>
42 
43 /* AMD756 SMBus address offsets */
44 #define SMB_ADDR_OFFSET		0xE0
45 #define SMB_IOSIZE		16
46 #define SMB_GLOBAL_STATUS	(0x0 + amd756_ioport)
47 #define SMB_GLOBAL_ENABLE	(0x2 + amd756_ioport)
48 #define SMB_HOST_ADDRESS	(0x4 + amd756_ioport)
49 #define SMB_HOST_DATA		(0x6 + amd756_ioport)
50 #define SMB_HOST_COMMAND	(0x8 + amd756_ioport)
51 #define SMB_HOST_BLOCK_DATA	(0x9 + amd756_ioport)
52 #define SMB_HAS_DATA		(0xA + amd756_ioport)
53 #define SMB_HAS_DEVICE_ADDRESS	(0xC + amd756_ioport)
54 #define SMB_HAS_HOST_ADDRESS	(0xE + amd756_ioport)
55 #define SMB_SNOOP_ADDRESS	(0xF + amd756_ioport)
56 
57 /* PCI Address Constants */
58 
59 /* address of I/O space */
60 #define SMBBA		0x058		/* mh */
61 #define SMBBANFORCE	0x014
62 
63 /* general configuration */
64 #define SMBGCFG		0x041		/* mh */
65 
66 /* silicon revision code */
67 #define SMBREV		0x008
68 
69 /* Other settings */
70 #define MAX_TIMEOUT	500
71 
72 /* AMD756 constants */
73 #define AMD756_QUICK		0x00
74 #define AMD756_BYTE		0x01
75 #define AMD756_BYTE_DATA	0x02
76 #define AMD756_WORD_DATA	0x03
77 #define AMD756_PROCESS_CALL	0x04
78 #define AMD756_BLOCK_DATA	0x05
79 
80 static struct pci_driver amd756_driver;
81 static unsigned short amd756_ioport;
82 
83 /*
84   SMBUS event = I/O 28-29 bit 11
85      see E0 for the status bits and enabled in E2
86 
87 */
88 #define GS_ABRT_STS	(1 << 0)
89 #define GS_COL_STS	(1 << 1)
90 #define GS_PRERR_STS	(1 << 2)
91 #define GS_HST_STS	(1 << 3)
92 #define GS_HCYC_STS	(1 << 4)
93 #define GS_TO_STS	(1 << 5)
94 #define GS_SMB_STS	(1 << 11)
95 
96 #define GS_CLEAR_STS	(GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
97 			 GS_HCYC_STS | GS_TO_STS )
98 
99 #define GE_CYC_TYPE_MASK	(7)
100 #define GE_HOST_STC		(1 << 3)
101 #define GE_ABORT		(1 << 5)
102 
103 
104 static int amd756_transaction(struct i2c_adapter *adap)
105 {
106 	int temp;
107 	int result = 0;
108 	int timeout = 0;
109 
110 	dev_dbg(&adap->dev, "Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, "
111 		"DAT=%04x\n", inw_p(SMB_GLOBAL_STATUS),
112 		inw_p(SMB_GLOBAL_ENABLE), inw_p(SMB_HOST_ADDRESS),
113 		inb_p(SMB_HOST_DATA));
114 
115 	/* Make sure the SMBus host is ready to start transmitting */
116 	if ((temp = inw_p(SMB_GLOBAL_STATUS)) & (GS_HST_STS | GS_SMB_STS)) {
117 		dev_dbg(&adap->dev, "SMBus busy (%04x). Waiting...\n", temp);
118 		do {
119 			msleep(1);
120 			temp = inw_p(SMB_GLOBAL_STATUS);
121 		} while ((temp & (GS_HST_STS | GS_SMB_STS)) &&
122 		         (timeout++ < MAX_TIMEOUT));
123 		/* If the SMBus is still busy, we give up */
124 		if (timeout > MAX_TIMEOUT) {
125 			dev_dbg(&adap->dev, "Busy wait timeout (%04x)\n", temp);
126 			goto abort;
127 		}
128 		timeout = 0;
129 	}
130 
131 	/* start the transaction by setting the start bit */
132 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);
133 
134 	/* We will always wait for a fraction of a second! */
135 	do {
136 		msleep(1);
137 		temp = inw_p(SMB_GLOBAL_STATUS);
138 	} while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));
139 
140 	/* If the SMBus is still busy, we give up */
141 	if (timeout > MAX_TIMEOUT) {
142 		dev_dbg(&adap->dev, "Completion timeout!\n");
143 		goto abort;
144 	}
145 
146 	if (temp & GS_PRERR_STS) {
147 		result = -ENXIO;
148 		dev_dbg(&adap->dev, "SMBus Protocol error (no response)!\n");
149 	}
150 
151 	if (temp & GS_COL_STS) {
152 		result = -EIO;
153 		dev_warn(&adap->dev, "SMBus collision!\n");
154 	}
155 
156 	if (temp & GS_TO_STS) {
157 		result = -ETIMEDOUT;
158 		dev_dbg(&adap->dev, "SMBus protocol timeout!\n");
159 	}
160 
161 	if (temp & GS_HCYC_STS)
162 		dev_dbg(&adap->dev, "SMBus protocol success!\n");
163 
164 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
165 
166 #ifdef DEBUG
167 	if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
168 		dev_dbg(&adap->dev,
169 			"Failed reset at end of transaction (%04x)\n", temp);
170 	}
171 #endif
172 
173 	dev_dbg(&adap->dev,
174 		"Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
175 		inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
176 		inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
177 
178 	return result;
179 
180  abort:
181 	dev_warn(&adap->dev, "Sending abort\n");
182 	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_ABORT, SMB_GLOBAL_ENABLE);
183 	msleep(100);
184 	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
185 	return -EIO;
186 }
187 
188 /* Return negative errno on error. */
189 static s32 amd756_access(struct i2c_adapter * adap, u16 addr,
190 		  unsigned short flags, char read_write,
191 		  u8 command, int size, union i2c_smbus_data * data)
192 {
193 	int i, len;
194 	int status;
195 
196 	switch (size) {
197 	case I2C_SMBUS_QUICK:
198 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
199 		       SMB_HOST_ADDRESS);
200 		size = AMD756_QUICK;
201 		break;
202 	case I2C_SMBUS_BYTE:
203 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
204 		       SMB_HOST_ADDRESS);
205 		if (read_write == I2C_SMBUS_WRITE)
206 			outb_p(command, SMB_HOST_DATA);
207 		size = AMD756_BYTE;
208 		break;
209 	case I2C_SMBUS_BYTE_DATA:
210 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
211 		       SMB_HOST_ADDRESS);
212 		outb_p(command, SMB_HOST_COMMAND);
213 		if (read_write == I2C_SMBUS_WRITE)
214 			outw_p(data->byte, SMB_HOST_DATA);
215 		size = AMD756_BYTE_DATA;
216 		break;
217 	case I2C_SMBUS_WORD_DATA:
218 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
219 		       SMB_HOST_ADDRESS);
220 		outb_p(command, SMB_HOST_COMMAND);
221 		if (read_write == I2C_SMBUS_WRITE)
222 			outw_p(data->word, SMB_HOST_DATA);	/* TODO: endian???? */
223 		size = AMD756_WORD_DATA;
224 		break;
225 	case I2C_SMBUS_BLOCK_DATA:
226 		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
227 		       SMB_HOST_ADDRESS);
228 		outb_p(command, SMB_HOST_COMMAND);
229 		if (read_write == I2C_SMBUS_WRITE) {
230 			len = data->block[0];
231 			if (len < 0)
232 				len = 0;
233 			if (len > 32)
234 				len = 32;
235 			outw_p(len, SMB_HOST_DATA);
236 			/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
237 			for (i = 1; i <= len; i++)
238 				outb_p(data->block[i],
239 				       SMB_HOST_BLOCK_DATA);
240 		}
241 		size = AMD756_BLOCK_DATA;
242 		break;
243 	default:
244 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
245 		return -EOPNOTSUPP;
246 	}
247 
248 	/* How about enabling interrupts... */
249 	outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);
250 
251 	status = amd756_transaction(adap);
252 	if (status)
253 		return status;
254 
255 	if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
256 		return 0;
257 
258 
259 	switch (size) {
260 	case AMD756_BYTE:
261 		data->byte = inw_p(SMB_HOST_DATA);
262 		break;
263 	case AMD756_BYTE_DATA:
264 		data->byte = inw_p(SMB_HOST_DATA);
265 		break;
266 	case AMD756_WORD_DATA:
267 		data->word = inw_p(SMB_HOST_DATA);	/* TODO: endian???? */
268 		break;
269 	case AMD756_BLOCK_DATA:
270 		data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;
271 		if(data->block[0] > 32)
272 			data->block[0] = 32;
273 		/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
274 		for (i = 1; i <= data->block[0]; i++)
275 			data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
276 		break;
277 	}
278 
279 	return 0;
280 }
281 
282 static u32 amd756_func(struct i2c_adapter *adapter)
283 {
284 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
285 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
286 	    I2C_FUNC_SMBUS_BLOCK_DATA;
287 }
288 
289 static const struct i2c_algorithm smbus_algorithm = {
290 	.smbus_xfer	= amd756_access,
291 	.functionality	= amd756_func,
292 };
293 
294 struct i2c_adapter amd756_smbus = {
295 	.owner		= THIS_MODULE,
296 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
297 	.algo		= &smbus_algorithm,
298 };
299 
300 enum chiptype { AMD756, AMD766, AMD768, NFORCE, AMD8111 };
301 static const char* chipname[] = {
302 	"AMD756", "AMD766", "AMD768",
303 	"nVidia nForce", "AMD8111",
304 };
305 
306 static const struct pci_device_id amd756_ids[] = {
307 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
308 	  .driver_data = AMD756 },
309 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),
310 	  .driver_data = AMD766 },
311 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_OPUS_7443),
312 	  .driver_data = AMD768 },
313 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS),
314 	  .driver_data = AMD8111 },
315 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_SMBUS),
316 	  .driver_data = NFORCE },
317 	{ 0, }
318 };
319 
320 MODULE_DEVICE_TABLE (pci, amd756_ids);
321 
322 static int amd756_probe(struct pci_dev *pdev, const struct pci_device_id *id)
323 {
324 	int nforce = (id->driver_data == NFORCE);
325 	int error;
326 	u8 temp;
327 
328 	if (amd756_ioport) {
329 		dev_err(&pdev->dev, "Only one device supported "
330 		       "(you have a strange motherboard, btw)\n");
331 		return -ENODEV;
332 	}
333 
334 	if (nforce) {
335 		if (PCI_FUNC(pdev->devfn) != 1)
336 			return -ENODEV;
337 
338 		pci_read_config_word(pdev, SMBBANFORCE, &amd756_ioport);
339 		amd756_ioport &= 0xfffc;
340 	} else { /* amd */
341 		if (PCI_FUNC(pdev->devfn) != 3)
342 			return -ENODEV;
343 
344 		pci_read_config_byte(pdev, SMBGCFG, &temp);
345 		if ((temp & 128) == 0) {
346 			dev_err(&pdev->dev,
347 				"Error: SMBus controller I/O not enabled!\n");
348 			return -ENODEV;
349 		}
350 
351 		/* Determine the address of the SMBus areas */
352 		/* Technically it is a dword but... */
353 		pci_read_config_word(pdev, SMBBA, &amd756_ioport);
354 		amd756_ioport &= 0xff00;
355 		amd756_ioport += SMB_ADDR_OFFSET;
356 	}
357 
358 	error = acpi_check_region(amd756_ioport, SMB_IOSIZE,
359 				  amd756_driver.name);
360 	if (error)
361 		return -ENODEV;
362 
363 	if (!request_region(amd756_ioport, SMB_IOSIZE, amd756_driver.name)) {
364 		dev_err(&pdev->dev, "SMB region 0x%x already in use!\n",
365 			amd756_ioport);
366 		return -ENODEV;
367 	}
368 
369 	pci_read_config_byte(pdev, SMBREV, &temp);
370 	dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
371 	dev_dbg(&pdev->dev, "AMD756_smba = 0x%X\n", amd756_ioport);
372 
373 	/* set up the sysfs linkage to our parent device */
374 	amd756_smbus.dev.parent = &pdev->dev;
375 
376 	snprintf(amd756_smbus.name, sizeof(amd756_smbus.name),
377 		 "SMBus %s adapter at %04x", chipname[id->driver_data],
378 		 amd756_ioport);
379 
380 	error = i2c_add_adapter(&amd756_smbus);
381 	if (error)
382 		goto out_err;
383 
384 	return 0;
385 
386  out_err:
387 	release_region(amd756_ioport, SMB_IOSIZE);
388 	return error;
389 }
390 
391 static void amd756_remove(struct pci_dev *dev)
392 {
393 	i2c_del_adapter(&amd756_smbus);
394 	release_region(amd756_ioport, SMB_IOSIZE);
395 }
396 
397 static struct pci_driver amd756_driver = {
398 	.name		= "amd756_smbus",
399 	.id_table	= amd756_ids,
400 	.probe		= amd756_probe,
401 	.remove		= amd756_remove,
402 };
403 
404 module_pci_driver(amd756_driver);
405 
406 MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
407 MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
408 MODULE_LICENSE("GPL");
409 
410 EXPORT_SYMBOL(amd756_smbus);
411