xref: /openbmc/linux/drivers/i2c/busses/i2c-amd8111.c (revision be709d48)
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/i2c.h>
17 #include <linux/delay.h>
18 #include <linux/acpi.h>
19 #include <linux/slab.h>
20 #include <linux/io.h>
21 
22 MODULE_LICENSE("GPL");
23 MODULE_AUTHOR ("Vojtech Pavlik <vojtech@suse.cz>");
24 MODULE_DESCRIPTION("AMD8111 SMBus 2.0 driver");
25 
26 struct amd_smbus {
27 	struct pci_dev *dev;
28 	struct i2c_adapter adapter;
29 	int base;
30 	int size;
31 };
32 
33 static struct pci_driver amd8111_driver;
34 
35 /*
36  * AMD PCI control registers definitions.
37  */
38 
39 #define AMD_PCI_MISC	0x48
40 
41 #define AMD_PCI_MISC_SCI	0x04	/* deliver SCI */
42 #define AMD_PCI_MISC_INT	0x02	/* deliver PCI IRQ */
43 #define AMD_PCI_MISC_SPEEDUP	0x01	/* 16x clock speedup */
44 
45 /*
46  * ACPI 2.0 chapter 13 PCI interface definitions.
47  */
48 
49 #define AMD_EC_DATA	0x00	/* data register */
50 #define AMD_EC_SC	0x04	/* status of controller */
51 #define AMD_EC_CMD	0x04	/* command register */
52 #define AMD_EC_ICR	0x08	/* interrupt control register */
53 
54 #define AMD_EC_SC_SMI	0x04	/* smi event pending */
55 #define AMD_EC_SC_SCI	0x02	/* sci event pending */
56 #define AMD_EC_SC_BURST	0x01	/* burst mode enabled */
57 #define AMD_EC_SC_CMD	0x08	/* byte in data reg is command */
58 #define AMD_EC_SC_IBF	0x02	/* data ready for embedded controller */
59 #define AMD_EC_SC_OBF	0x01	/* data ready for host */
60 
61 #define AMD_EC_CMD_RD	0x80	/* read EC */
62 #define AMD_EC_CMD_WR	0x81	/* write EC */
63 #define AMD_EC_CMD_BE	0x82	/* enable burst mode */
64 #define AMD_EC_CMD_BD	0x83	/* disable burst mode */
65 #define AMD_EC_CMD_QR	0x84	/* query EC */
66 
67 /*
68  * ACPI 2.0 chapter 13 access of registers of the EC
69  */
70 
71 static int amd_ec_wait_write(struct amd_smbus *smbus)
72 {
73 	int timeout = 500;
74 
75 	while ((inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF) && --timeout)
76 		udelay(1);
77 
78 	if (!timeout) {
79 		dev_warn(&smbus->dev->dev,
80 			 "Timeout while waiting for IBF to clear\n");
81 		return -ETIMEDOUT;
82 	}
83 
84 	return 0;
85 }
86 
87 static int amd_ec_wait_read(struct amd_smbus *smbus)
88 {
89 	int timeout = 500;
90 
91 	while ((~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF) && --timeout)
92 		udelay(1);
93 
94 	if (!timeout) {
95 		dev_warn(&smbus->dev->dev,
96 			 "Timeout while waiting for OBF to set\n");
97 		return -ETIMEDOUT;
98 	}
99 
100 	return 0;
101 }
102 
103 static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
104 		unsigned char *data)
105 {
106 	int status;
107 
108 	status = amd_ec_wait_write(smbus);
109 	if (status)
110 		return status;
111 	outb(AMD_EC_CMD_RD, smbus->base + AMD_EC_CMD);
112 
113 	status = amd_ec_wait_write(smbus);
114 	if (status)
115 		return status;
116 	outb(address, smbus->base + AMD_EC_DATA);
117 
118 	status = amd_ec_wait_read(smbus);
119 	if (status)
120 		return status;
121 	*data = inb(smbus->base + AMD_EC_DATA);
122 
123 	return 0;
124 }
125 
126 static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
127 		unsigned char data)
128 {
129 	int status;
130 
131 	status = amd_ec_wait_write(smbus);
132 	if (status)
133 		return status;
134 	outb(AMD_EC_CMD_WR, smbus->base + AMD_EC_CMD);
135 
136 	status = amd_ec_wait_write(smbus);
137 	if (status)
138 		return status;
139 	outb(address, smbus->base + AMD_EC_DATA);
140 
141 	status = amd_ec_wait_write(smbus);
142 	if (status)
143 		return status;
144 	outb(data, smbus->base + AMD_EC_DATA);
145 
146 	return 0;
147 }
148 
149 /*
150  * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
151  */
152 
153 #define AMD_SMB_PRTCL	0x00	/* protocol, PEC */
154 #define AMD_SMB_STS	0x01	/* status */
155 #define AMD_SMB_ADDR	0x02	/* address */
156 #define AMD_SMB_CMD	0x03	/* command */
157 #define AMD_SMB_DATA	0x04	/* 32 data registers */
158 #define AMD_SMB_BCNT	0x24	/* number of data bytes */
159 #define AMD_SMB_ALRM_A	0x25	/* alarm address */
160 #define AMD_SMB_ALRM_D	0x26	/* 2 bytes alarm data */
161 
162 #define AMD_SMB_STS_DONE	0x80
163 #define AMD_SMB_STS_ALRM	0x40
164 #define AMD_SMB_STS_RES		0x20
165 #define AMD_SMB_STS_STATUS	0x1f
166 
167 #define AMD_SMB_STATUS_OK	0x00
168 #define AMD_SMB_STATUS_FAIL	0x07
169 #define AMD_SMB_STATUS_DNAK	0x10
170 #define AMD_SMB_STATUS_DERR	0x11
171 #define AMD_SMB_STATUS_CMD_DENY	0x12
172 #define AMD_SMB_STATUS_UNKNOWN	0x13
173 #define AMD_SMB_STATUS_ACC_DENY	0x17
174 #define AMD_SMB_STATUS_TIMEOUT	0x18
175 #define AMD_SMB_STATUS_NOTSUP	0x19
176 #define AMD_SMB_STATUS_BUSY	0x1A
177 #define AMD_SMB_STATUS_PEC	0x1F
178 
179 #define AMD_SMB_PRTCL_WRITE		0x00
180 #define AMD_SMB_PRTCL_READ		0x01
181 #define AMD_SMB_PRTCL_QUICK		0x02
182 #define AMD_SMB_PRTCL_BYTE		0x04
183 #define AMD_SMB_PRTCL_BYTE_DATA		0x06
184 #define AMD_SMB_PRTCL_WORD_DATA		0x08
185 #define AMD_SMB_PRTCL_BLOCK_DATA	0x0a
186 #define AMD_SMB_PRTCL_PROC_CALL		0x0c
187 #define AMD_SMB_PRTCL_BLOCK_PROC_CALL	0x0d
188 #define AMD_SMB_PRTCL_I2C_BLOCK_DATA	0x4a
189 #define AMD_SMB_PRTCL_PEC		0x80
190 
191 
192 static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
193 		unsigned short flags, char read_write, u8 command, int size,
194 		union i2c_smbus_data * data)
195 {
196 	struct amd_smbus *smbus = adap->algo_data;
197 	unsigned char protocol, len, pec, temp[2];
198 	int i, status;
199 
200 	protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
201 						  : AMD_SMB_PRTCL_WRITE;
202 	pec = (flags & I2C_CLIENT_PEC) ? AMD_SMB_PRTCL_PEC : 0;
203 
204 	switch (size) {
205 		case I2C_SMBUS_QUICK:
206 			protocol |= AMD_SMB_PRTCL_QUICK;
207 			read_write = I2C_SMBUS_WRITE;
208 			break;
209 
210 		case I2C_SMBUS_BYTE:
211 			if (read_write == I2C_SMBUS_WRITE) {
212 				status = amd_ec_write(smbus, AMD_SMB_CMD,
213 						      command);
214 				if (status)
215 					return status;
216 			}
217 			protocol |= AMD_SMB_PRTCL_BYTE;
218 			break;
219 
220 		case I2C_SMBUS_BYTE_DATA:
221 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
222 			if (status)
223 				return status;
224 			if (read_write == I2C_SMBUS_WRITE) {
225 				status = amd_ec_write(smbus, AMD_SMB_DATA,
226 						      data->byte);
227 				if (status)
228 					return status;
229 			}
230 			protocol |= AMD_SMB_PRTCL_BYTE_DATA;
231 			break;
232 
233 		case I2C_SMBUS_WORD_DATA:
234 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
235 			if (status)
236 				return status;
237 			if (read_write == I2C_SMBUS_WRITE) {
238 				status = amd_ec_write(smbus, AMD_SMB_DATA,
239 						      data->word & 0xff);
240 				if (status)
241 					return status;
242 				status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
243 						      data->word >> 8);
244 				if (status)
245 					return status;
246 			}
247 			protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
248 			break;
249 
250 		case I2C_SMBUS_BLOCK_DATA:
251 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
252 			if (status)
253 				return status;
254 			if (read_write == I2C_SMBUS_WRITE) {
255 				len = min_t(u8, data->block[0],
256 					    I2C_SMBUS_BLOCK_MAX);
257 				status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
258 				if (status)
259 					return status;
260 				for (i = 0; i < len; i++) {
261 					status =
262 					  amd_ec_write(smbus, AMD_SMB_DATA + i,
263 						       data->block[i + 1]);
264 					if (status)
265 						return status;
266 				}
267 			}
268 			protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
269 			break;
270 
271 		case I2C_SMBUS_I2C_BLOCK_DATA:
272 			len = min_t(u8, data->block[0],
273 				    I2C_SMBUS_BLOCK_MAX);
274 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
275 			if (status)
276 				return status;
277 			status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
278 			if (status)
279 				return status;
280 			if (read_write == I2C_SMBUS_WRITE)
281 				for (i = 0; i < len; i++) {
282 					status =
283 					  amd_ec_write(smbus, AMD_SMB_DATA + i,
284 						       data->block[i + 1]);
285 					if (status)
286 						return status;
287 				}
288 			protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
289 			break;
290 
291 		case I2C_SMBUS_PROC_CALL:
292 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
293 			if (status)
294 				return status;
295 			status = amd_ec_write(smbus, AMD_SMB_DATA,
296 					      data->word & 0xff);
297 			if (status)
298 				return status;
299 			status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
300 					      data->word >> 8);
301 			if (status)
302 				return status;
303 			protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
304 			read_write = I2C_SMBUS_READ;
305 			break;
306 
307 		case I2C_SMBUS_BLOCK_PROC_CALL:
308 			len = min_t(u8, data->block[0],
309 				    I2C_SMBUS_BLOCK_MAX - 1);
310 			status = amd_ec_write(smbus, AMD_SMB_CMD, command);
311 			if (status)
312 				return status;
313 			status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
314 			if (status)
315 				return status;
316 			for (i = 0; i < len; i++) {
317 				status = amd_ec_write(smbus, AMD_SMB_DATA + i,
318 						      data->block[i + 1]);
319 				if (status)
320 					return status;
321 			}
322 			protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
323 			read_write = I2C_SMBUS_READ;
324 			break;
325 
326 		default:
327 			dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
328 			return -EOPNOTSUPP;
329 	}
330 
331 	status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
332 	if (status)
333 		return status;
334 	status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
335 	if (status)
336 		return status;
337 
338 	status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
339 	if (status)
340 		return status;
341 
342 	if (~temp[0] & AMD_SMB_STS_DONE) {
343 		udelay(500);
344 		status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
345 		if (status)
346 			return status;
347 	}
348 
349 	if (~temp[0] & AMD_SMB_STS_DONE) {
350 		msleep(1);
351 		status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
352 		if (status)
353 			return status;
354 	}
355 
356 	if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
357 		return -EIO;
358 
359 	if (read_write == I2C_SMBUS_WRITE)
360 		return 0;
361 
362 	switch (size) {
363 		case I2C_SMBUS_BYTE:
364 		case I2C_SMBUS_BYTE_DATA:
365 			status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
366 			if (status)
367 				return status;
368 			break;
369 
370 		case I2C_SMBUS_WORD_DATA:
371 		case I2C_SMBUS_PROC_CALL:
372 			status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
373 			if (status)
374 				return status;
375 			status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
376 			if (status)
377 				return status;
378 			data->word = (temp[1] << 8) | temp[0];
379 			break;
380 
381 		case I2C_SMBUS_BLOCK_DATA:
382 		case I2C_SMBUS_BLOCK_PROC_CALL:
383 			status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
384 			if (status)
385 				return status;
386 			len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
387 			/* fall through */
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 const struct pci_device_id 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 amd8111_probe(struct pci_dev *dev, const struct pci_device_id *id)
426 {
427 	struct amd_smbus *smbus;
428 	int error;
429 
430 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
431 		return -ENODEV;
432 
433 	smbus = kzalloc(sizeof(struct amd_smbus), GFP_KERNEL);
434 	if (!smbus)
435 		return -ENOMEM;
436 
437 	smbus->dev = dev;
438 	smbus->base = pci_resource_start(dev, 0);
439 	smbus->size = pci_resource_len(dev, 0);
440 
441 	error = acpi_check_resource_conflict(&dev->resource[0]);
442 	if (error) {
443 		error = -ENODEV;
444 		goto out_kfree;
445 	}
446 
447 	if (!request_region(smbus->base, smbus->size, amd8111_driver.name)) {
448 		error = -EBUSY;
449 		goto out_kfree;
450 	}
451 
452 	smbus->adapter.owner = THIS_MODULE;
453 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
454 		"SMBus2 AMD8111 adapter at %04x", smbus->base);
455 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
456 	smbus->adapter.algo = &smbus_algorithm;
457 	smbus->adapter.algo_data = smbus;
458 
459 	/* set up the sysfs linkage to our parent device */
460 	smbus->adapter.dev.parent = &dev->dev;
461 
462 	pci_write_config_dword(smbus->dev, AMD_PCI_MISC, 0);
463 	error = i2c_add_adapter(&smbus->adapter);
464 	if (error)
465 		goto out_release_region;
466 
467 	pci_set_drvdata(dev, smbus);
468 	return 0;
469 
470  out_release_region:
471 	release_region(smbus->base, smbus->size);
472  out_kfree:
473 	kfree(smbus);
474 	return error;
475 }
476 
477 static void amd8111_remove(struct pci_dev *dev)
478 {
479 	struct amd_smbus *smbus = pci_get_drvdata(dev);
480 
481 	i2c_del_adapter(&smbus->adapter);
482 	release_region(smbus->base, smbus->size);
483 	kfree(smbus);
484 }
485 
486 static struct pci_driver amd8111_driver = {
487 	.name		= "amd8111_smbus2",
488 	.id_table	= amd8111_ids,
489 	.probe		= amd8111_probe,
490 	.remove		= amd8111_remove,
491 };
492 
493 module_pci_driver(amd8111_driver);
494