xref: /openbmc/linux/drivers/i2c/busses/i2c-amd8111.c (revision 63dc02bd)
1 /*
2  * SMBus 2.0 driver for AMD-8111 IO-Hub.
3  *
4  * Copyright (c) 2002 Vojtech Pavlik
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation version 2.
9  */
10 
11 #include <linux/module.h>
12 #include <linux/pci.h>
13 #include <linux/kernel.h>
14 #include <linux/stddef.h>
15 #include <linux/ioport.h>
16 #include <linux/init.h>
17 #include <linux/i2c.h>
18 #include <linux/delay.h>
19 #include <linux/acpi.h>
20 #include <linux/slab.h>
21 #include <linux/io.h>
22 
23 MODULE_LICENSE("GPL");
24 MODULE_AUTHOR ("Vojtech Pavlik <vojtech@suse.cz>");
25 MODULE_DESCRIPTION("AMD8111 SMBus 2.0 driver");
26 
27 struct amd_smbus {
28 	struct pci_dev *dev;
29 	struct i2c_adapter adapter;
30 	int base;
31 	int size;
32 };
33 
34 static struct pci_driver amd8111_driver;
35 
36 /*
37  * AMD PCI control registers definitions.
38  */
39 
40 #define AMD_PCI_MISC	0x48
41 
42 #define AMD_PCI_MISC_SCI	0x04	/* deliver SCI */
43 #define AMD_PCI_MISC_INT	0x02	/* deliver PCI IRQ */
44 #define AMD_PCI_MISC_SPEEDUP	0x01	/* 16x clock speedup */
45 
46 /*
47  * ACPI 2.0 chapter 13 PCI interface definitions.
48  */
49 
50 #define AMD_EC_DATA	0x00	/* data register */
51 #define AMD_EC_SC	0x04	/* status of controller */
52 #define AMD_EC_CMD	0x04	/* command register */
53 #define AMD_EC_ICR	0x08	/* interrupt control register */
54 
55 #define AMD_EC_SC_SMI	0x04	/* smi event pending */
56 #define AMD_EC_SC_SCI	0x02	/* sci event pending */
57 #define AMD_EC_SC_BURST	0x01	/* burst mode enabled */
58 #define AMD_EC_SC_CMD	0x08	/* byte in data reg is command */
59 #define AMD_EC_SC_IBF	0x02	/* data ready for embedded controller */
60 #define AMD_EC_SC_OBF	0x01	/* data ready for host */
61 
62 #define AMD_EC_CMD_RD	0x80	/* read EC */
63 #define AMD_EC_CMD_WR	0x81	/* write EC */
64 #define AMD_EC_CMD_BE	0x82	/* enable burst mode */
65 #define AMD_EC_CMD_BD	0x83	/* disable burst mode */
66 #define AMD_EC_CMD_QR	0x84	/* query EC */
67 
68 /*
69  * ACPI 2.0 chapter 13 access of registers of the EC
70  */
71 
72 static int amd_ec_wait_write(struct amd_smbus *smbus)
73 {
74 	int timeout = 500;
75 
76 	while ((inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF) && --timeout)
77 		udelay(1);
78 
79 	if (!timeout) {
80 		dev_warn(&smbus->dev->dev,
81 			 "Timeout while waiting for IBF to clear\n");
82 		return -ETIMEDOUT;
83 	}
84 
85 	return 0;
86 }
87 
88 static int amd_ec_wait_read(struct amd_smbus *smbus)
89 {
90 	int timeout = 500;
91 
92 	while ((~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF) && --timeout)
93 		udelay(1);
94 
95 	if (!timeout) {
96 		dev_warn(&smbus->dev->dev,
97 			 "Timeout while waiting for OBF to set\n");
98 		return -ETIMEDOUT;
99 	}
100 
101 	return 0;
102 }
103 
104 static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
105 		unsigned char *data)
106 {
107 	int status;
108 
109 	status = amd_ec_wait_write(smbus);
110 	if (status)
111 		return status;
112 	outb(AMD_EC_CMD_RD, smbus->base + AMD_EC_CMD);
113 
114 	status = amd_ec_wait_write(smbus);
115 	if (status)
116 		return status;
117 	outb(address, smbus->base + AMD_EC_DATA);
118 
119 	status = amd_ec_wait_read(smbus);
120 	if (status)
121 		return status;
122 	*data = inb(smbus->base + AMD_EC_DATA);
123 
124 	return 0;
125 }
126 
127 static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
128 		unsigned char data)
129 {
130 	int status;
131 
132 	status = amd_ec_wait_write(smbus);
133 	if (status)
134 		return status;
135 	outb(AMD_EC_CMD_WR, smbus->base + AMD_EC_CMD);
136 
137 	status = amd_ec_wait_write(smbus);
138 	if (status)
139 		return status;
140 	outb(address, smbus->base + AMD_EC_DATA);
141 
142 	status = amd_ec_wait_write(smbus);
143 	if (status)
144 		return status;
145 	outb(data, smbus->base + AMD_EC_DATA);
146 
147 	return 0;
148 }
149 
150 /*
151  * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
152  */
153 
154 #define AMD_SMB_PRTCL	0x00	/* protocol, PEC */
155 #define AMD_SMB_STS	0x01	/* status */
156 #define AMD_SMB_ADDR	0x02	/* address */
157 #define AMD_SMB_CMD	0x03	/* command */
158 #define AMD_SMB_DATA	0x04	/* 32 data registers */
159 #define AMD_SMB_BCNT	0x24	/* number of data bytes */
160 #define AMD_SMB_ALRM_A	0x25	/* alarm address */
161 #define AMD_SMB_ALRM_D	0x26	/* 2 bytes alarm data */
162 
163 #define AMD_SMB_STS_DONE	0x80
164 #define AMD_SMB_STS_ALRM	0x40
165 #define AMD_SMB_STS_RES		0x20
166 #define AMD_SMB_STS_STATUS	0x1f
167 
168 #define AMD_SMB_STATUS_OK	0x00
169 #define AMD_SMB_STATUS_FAIL	0x07
170 #define AMD_SMB_STATUS_DNAK	0x10
171 #define AMD_SMB_STATUS_DERR	0x11
172 #define AMD_SMB_STATUS_CMD_DENY	0x12
173 #define AMD_SMB_STATUS_UNKNOWN	0x13
174 #define AMD_SMB_STATUS_ACC_DENY	0x17
175 #define AMD_SMB_STATUS_TIMEOUT	0x18
176 #define AMD_SMB_STATUS_NOTSUP	0x19
177 #define AMD_SMB_STATUS_BUSY	0x1A
178 #define AMD_SMB_STATUS_PEC	0x1F
179 
180 #define AMD_SMB_PRTCL_WRITE		0x00
181 #define AMD_SMB_PRTCL_READ		0x01
182 #define AMD_SMB_PRTCL_QUICK		0x02
183 #define AMD_SMB_PRTCL_BYTE		0x04
184 #define AMD_SMB_PRTCL_BYTE_DATA		0x06
185 #define AMD_SMB_PRTCL_WORD_DATA		0x08
186 #define AMD_SMB_PRTCL_BLOCK_DATA	0x0a
187 #define AMD_SMB_PRTCL_PROC_CALL		0x0c
188 #define AMD_SMB_PRTCL_BLOCK_PROC_CALL	0x0d
189 #define AMD_SMB_PRTCL_I2C_BLOCK_DATA	0x4a
190 #define AMD_SMB_PRTCL_PEC		0x80
191 
192 
193 static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
194 		unsigned short flags, char read_write, u8 command, int size,
195 		union i2c_smbus_data * data)
196 {
197 	struct amd_smbus *smbus = adap->algo_data;
198 	unsigned char protocol, len, pec, temp[2];
199 	int i, status;
200 
201 	protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
202 						  : AMD_SMB_PRTCL_WRITE;
203 	pec = (flags & I2C_CLIENT_PEC) ? AMD_SMB_PRTCL_PEC : 0;
204 
205 	switch (size) {
206 		case I2C_SMBUS_QUICK:
207 			protocol |= AMD_SMB_PRTCL_QUICK;
208 			read_write = I2C_SMBUS_WRITE;
209 			break;
210 
211 		case I2C_SMBUS_BYTE:
212 			if (read_write == I2C_SMBUS_WRITE) {
213 				status = amd_ec_write(smbus, AMD_SMB_CMD,
214 						      command);
215 				if (status)
216 					return status;
217 			}
218 			protocol |= AMD_SMB_PRTCL_BYTE;
219 			break;
220 
221 		case I2C_SMBUS_BYTE_DATA:
222 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
223 			if (status)
224 				return status;
225 			if (read_write == I2C_SMBUS_WRITE) {
226 				status = amd_ec_write(smbus, AMD_SMB_DATA,
227 						      data->byte);
228 				if (status)
229 					return status;
230 			}
231 			protocol |= AMD_SMB_PRTCL_BYTE_DATA;
232 			break;
233 
234 		case I2C_SMBUS_WORD_DATA:
235 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
236 			if (status)
237 				return status;
238 			if (read_write == I2C_SMBUS_WRITE) {
239 				status = amd_ec_write(smbus, AMD_SMB_DATA,
240 						      data->word & 0xff);
241 				if (status)
242 					return status;
243 				status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
244 						      data->word >> 8);
245 				if (status)
246 					return status;
247 			}
248 			protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
249 			break;
250 
251 		case I2C_SMBUS_BLOCK_DATA:
252 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
253 			if (status)
254 				return status;
255 			if (read_write == I2C_SMBUS_WRITE) {
256 				len = min_t(u8, data->block[0],
257 					    I2C_SMBUS_BLOCK_MAX);
258 				status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
259 				if (status)
260 					return status;
261 				for (i = 0; i < len; i++) {
262 					status =
263 					  amd_ec_write(smbus, AMD_SMB_DATA + i,
264 						       data->block[i + 1]);
265 					if (status)
266 						return status;
267 				}
268 			}
269 			protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
270 			break;
271 
272 		case I2C_SMBUS_I2C_BLOCK_DATA:
273 			len = min_t(u8, data->block[0],
274 				    I2C_SMBUS_BLOCK_MAX);
275 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
276 			if (status)
277 				return status;
278 			status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
279 			if (status)
280 				return status;
281 			if (read_write == I2C_SMBUS_WRITE)
282 				for (i = 0; i < len; i++) {
283 					status =
284 					  amd_ec_write(smbus, AMD_SMB_DATA + i,
285 						       data->block[i + 1]);
286 					if (status)
287 						return status;
288 				}
289 			protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
290 			break;
291 
292 		case I2C_SMBUS_PROC_CALL:
293 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
294 			if (status)
295 				return status;
296 			status = amd_ec_write(smbus, AMD_SMB_DATA,
297 					      data->word & 0xff);
298 			if (status)
299 				return status;
300 			status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
301 					      data->word >> 8);
302 			if (status)
303 				return status;
304 			protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
305 			read_write = I2C_SMBUS_READ;
306 			break;
307 
308 		case I2C_SMBUS_BLOCK_PROC_CALL:
309 			len = min_t(u8, data->block[0],
310 				    I2C_SMBUS_BLOCK_MAX - 1);
311 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
312 			if (status)
313 				return status;
314 			status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
315 			if (status)
316 				return status;
317 			for (i = 0; i < len; i++) {
318 				status = amd_ec_write(smbus, AMD_SMB_DATA + i,
319 						      data->block[i + 1]);
320 				if (status)
321 					return status;
322 			}
323 			protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
324 			read_write = I2C_SMBUS_READ;
325 			break;
326 
327 		default:
328 			dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
329 			return -EOPNOTSUPP;
330 	}
331 
332 	status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
333 	if (status)
334 		return status;
335 	status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
336 	if (status)
337 		return status;
338 
339 	status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
340 	if (status)
341 		return status;
342 
343 	if (~temp[0] & AMD_SMB_STS_DONE) {
344 		udelay(500);
345 		status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
346 		if (status)
347 			return status;
348 	}
349 
350 	if (~temp[0] & AMD_SMB_STS_DONE) {
351 		msleep(1);
352 		status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
353 		if (status)
354 			return status;
355 	}
356 
357 	if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
358 		return -EIO;
359 
360 	if (read_write == I2C_SMBUS_WRITE)
361 		return 0;
362 
363 	switch (size) {
364 		case I2C_SMBUS_BYTE:
365 		case I2C_SMBUS_BYTE_DATA:
366 			status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
367 			if (status)
368 				return status;
369 			break;
370 
371 		case I2C_SMBUS_WORD_DATA:
372 		case I2C_SMBUS_PROC_CALL:
373 			status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
374 			if (status)
375 				return status;
376 			status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
377 			if (status)
378 				return status;
379 			data->word = (temp[1] << 8) | temp[0];
380 			break;
381 
382 		case I2C_SMBUS_BLOCK_DATA:
383 		case I2C_SMBUS_BLOCK_PROC_CALL:
384 			status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
385 			if (status)
386 				return status;
387 			len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
388 		case I2C_SMBUS_I2C_BLOCK_DATA:
389 			for (i = 0; i < len; i++) {
390 				status = amd_ec_read(smbus, AMD_SMB_DATA + i,
391 						     data->block + i + 1);
392 				if (status)
393 					return status;
394 			}
395 			data->block[0] = len;
396 			break;
397 	}
398 
399 	return 0;
400 }
401 
402 
403 static u32 amd8111_func(struct i2c_adapter *adapter)
404 {
405 	return	I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
406 		I2C_FUNC_SMBUS_BYTE_DATA |
407 		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA |
408 		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
409 		I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PEC;
410 }
411 
412 static const struct i2c_algorithm smbus_algorithm = {
413 	.smbus_xfer = amd8111_access,
414 	.functionality = amd8111_func,
415 };
416 
417 
418 static DEFINE_PCI_DEVICE_TABLE(amd8111_ids) = {
419 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS2) },
420 	{ 0, }
421 };
422 
423 MODULE_DEVICE_TABLE (pci, amd8111_ids);
424 
425 static int __devinit amd8111_probe(struct pci_dev *dev,
426 		const struct pci_device_id *id)
427 {
428 	struct amd_smbus *smbus;
429 	int error;
430 
431 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
432 		return -ENODEV;
433 
434 	smbus = kzalloc(sizeof(struct amd_smbus), GFP_KERNEL);
435 	if (!smbus)
436 		return -ENOMEM;
437 
438 	smbus->dev = dev;
439 	smbus->base = pci_resource_start(dev, 0);
440 	smbus->size = pci_resource_len(dev, 0);
441 
442 	error = acpi_check_resource_conflict(&dev->resource[0]);
443 	if (error) {
444 		error = -ENODEV;
445 		goto out_kfree;
446 	}
447 
448 	if (!request_region(smbus->base, smbus->size, amd8111_driver.name)) {
449 		error = -EBUSY;
450 		goto out_kfree;
451 	}
452 
453 	smbus->adapter.owner = THIS_MODULE;
454 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
455 		"SMBus2 AMD8111 adapter at %04x", smbus->base);
456 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
457 	smbus->adapter.algo = &smbus_algorithm;
458 	smbus->adapter.algo_data = smbus;
459 
460 	/* set up the sysfs linkage to our parent device */
461 	smbus->adapter.dev.parent = &dev->dev;
462 
463 	pci_write_config_dword(smbus->dev, AMD_PCI_MISC, 0);
464 	error = i2c_add_adapter(&smbus->adapter);
465 	if (error)
466 		goto out_release_region;
467 
468 	pci_set_drvdata(dev, smbus);
469 	return 0;
470 
471  out_release_region:
472 	release_region(smbus->base, smbus->size);
473  out_kfree:
474 	kfree(smbus);
475 	return error;
476 }
477 
478 static void __devexit amd8111_remove(struct pci_dev *dev)
479 {
480 	struct amd_smbus *smbus = pci_get_drvdata(dev);
481 
482 	i2c_del_adapter(&smbus->adapter);
483 	release_region(smbus->base, smbus->size);
484 	kfree(smbus);
485 }
486 
487 static struct pci_driver amd8111_driver = {
488 	.name		= "amd8111_smbus2",
489 	.id_table	= amd8111_ids,
490 	.probe		= amd8111_probe,
491 	.remove		= __devexit_p(amd8111_remove),
492 };
493 
494 static int __init i2c_amd8111_init(void)
495 {
496 	return pci_register_driver(&amd8111_driver);
497 }
498 
499 static void __exit i2c_amd8111_exit(void)
500 {
501 	pci_unregister_driver(&amd8111_driver);
502 }
503 
504 module_init(i2c_amd8111_init);
505 module_exit(i2c_amd8111_exit);
506