xref: /openbmc/linux/drivers/i2c/busses/i2c-amd8111.c (revision b627b4ed)
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 <asm/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 unsigned 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 unsigned 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 unsigned 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 unsigned 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;
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 				amd_ec_write(smbus, AMD_SMB_CMD, command);
213 			protocol |= AMD_SMB_PRTCL_BYTE;
214 			break;
215 
216 		case I2C_SMBUS_BYTE_DATA:
217 			amd_ec_write(smbus, AMD_SMB_CMD, command);
218 			if (read_write == I2C_SMBUS_WRITE)
219 				amd_ec_write(smbus, AMD_SMB_DATA, data->byte);
220 			protocol |= AMD_SMB_PRTCL_BYTE_DATA;
221 			break;
222 
223 		case I2C_SMBUS_WORD_DATA:
224 			amd_ec_write(smbus, AMD_SMB_CMD, command);
225 			if (read_write == I2C_SMBUS_WRITE) {
226 				amd_ec_write(smbus, AMD_SMB_DATA,
227 					     data->word & 0xff);
228 				amd_ec_write(smbus, AMD_SMB_DATA + 1,
229 					     data->word >> 8);
230 			}
231 			protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
232 			break;
233 
234 		case I2C_SMBUS_BLOCK_DATA:
235 			amd_ec_write(smbus, AMD_SMB_CMD, command);
236 			if (read_write == I2C_SMBUS_WRITE) {
237 				len = min_t(u8, data->block[0],
238 					    I2C_SMBUS_BLOCK_MAX);
239 				amd_ec_write(smbus, AMD_SMB_BCNT, len);
240 				for (i = 0; i < len; i++)
241 					amd_ec_write(smbus, AMD_SMB_DATA + i,
242 						     data->block[i + 1]);
243 			}
244 			protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
245 			break;
246 
247 		case I2C_SMBUS_I2C_BLOCK_DATA:
248 			len = min_t(u8, data->block[0],
249 				    I2C_SMBUS_BLOCK_MAX);
250 			amd_ec_write(smbus, AMD_SMB_CMD, command);
251 			amd_ec_write(smbus, AMD_SMB_BCNT, len);
252 			if (read_write == I2C_SMBUS_WRITE)
253 				for (i = 0; i < len; i++)
254 					amd_ec_write(smbus, AMD_SMB_DATA + i,
255 						     data->block[i + 1]);
256 			protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
257 			break;
258 
259 		case I2C_SMBUS_PROC_CALL:
260 			amd_ec_write(smbus, AMD_SMB_CMD, command);
261 			amd_ec_write(smbus, AMD_SMB_DATA, data->word & 0xff);
262 			amd_ec_write(smbus, AMD_SMB_DATA + 1, data->word >> 8);
263 			protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
264 			read_write = I2C_SMBUS_READ;
265 			break;
266 
267 		case I2C_SMBUS_BLOCK_PROC_CALL:
268 			len = min_t(u8, data->block[0],
269 				    I2C_SMBUS_BLOCK_MAX - 1);
270 			amd_ec_write(smbus, AMD_SMB_CMD, command);
271 			amd_ec_write(smbus, AMD_SMB_BCNT, len);
272 			for (i = 0; i < len; i++)
273 				amd_ec_write(smbus, AMD_SMB_DATA + i,
274 					     data->block[i + 1]);
275 			protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
276 			read_write = I2C_SMBUS_READ;
277 			break;
278 
279 		default:
280 			dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
281 			return -EOPNOTSUPP;
282 	}
283 
284 	amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
285 	amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
286 
287 	/* FIXME this discards status from ec_read(); so temp[0] will
288 	 * hold stack garbage ... the rest of this routine will act
289 	 * nonsensically.  Ignored ec_write() status might explain
290 	 * some such failures...
291 	 */
292 	amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
293 
294 	if (~temp[0] & AMD_SMB_STS_DONE) {
295 		udelay(500);
296 		amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
297 	}
298 
299 	if (~temp[0] & AMD_SMB_STS_DONE) {
300 		msleep(1);
301 		amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
302 	}
303 
304 	if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
305 		return -EIO;
306 
307 	if (read_write == I2C_SMBUS_WRITE)
308 		return 0;
309 
310 	switch (size) {
311 		case I2C_SMBUS_BYTE:
312 		case I2C_SMBUS_BYTE_DATA:
313 			amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
314 			break;
315 
316 		case I2C_SMBUS_WORD_DATA:
317 		case I2C_SMBUS_PROC_CALL:
318 			amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
319 			amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
320 			data->word = (temp[1] << 8) | temp[0];
321 			break;
322 
323 		case I2C_SMBUS_BLOCK_DATA:
324 		case I2C_SMBUS_BLOCK_PROC_CALL:
325 			amd_ec_read(smbus, AMD_SMB_BCNT, &len);
326 			len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
327 		case I2C_SMBUS_I2C_BLOCK_DATA:
328 			for (i = 0; i < len; i++)
329 				amd_ec_read(smbus, AMD_SMB_DATA + i,
330 					    data->block + i + 1);
331 			data->block[0] = len;
332 			break;
333 	}
334 
335 	return 0;
336 }
337 
338 
339 static u32 amd8111_func(struct i2c_adapter *adapter)
340 {
341 	return	I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
342 		I2C_FUNC_SMBUS_BYTE_DATA |
343 		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA |
344 		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
345 		I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PEC;
346 }
347 
348 static const struct i2c_algorithm smbus_algorithm = {
349 	.smbus_xfer = amd8111_access,
350 	.functionality = amd8111_func,
351 };
352 
353 
354 static struct pci_device_id amd8111_ids[] = {
355 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS2) },
356 	{ 0, }
357 };
358 
359 MODULE_DEVICE_TABLE (pci, amd8111_ids);
360 
361 static int __devinit amd8111_probe(struct pci_dev *dev,
362 		const struct pci_device_id *id)
363 {
364 	struct amd_smbus *smbus;
365 	int error;
366 
367 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
368 		return -ENODEV;
369 
370 	smbus = kzalloc(sizeof(struct amd_smbus), GFP_KERNEL);
371 	if (!smbus)
372 		return -ENOMEM;
373 
374 	smbus->dev = dev;
375 	smbus->base = pci_resource_start(dev, 0);
376 	smbus->size = pci_resource_len(dev, 0);
377 
378 	error = acpi_check_resource_conflict(&dev->resource[0]);
379 	if (error)
380 		goto out_kfree;
381 
382 	if (!request_region(smbus->base, smbus->size, amd8111_driver.name)) {
383 		error = -EBUSY;
384 		goto out_kfree;
385 	}
386 
387 	smbus->adapter.owner = THIS_MODULE;
388 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
389 		"SMBus2 AMD8111 adapter at %04x", smbus->base);
390 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
391 	smbus->adapter.algo = &smbus_algorithm;
392 	smbus->adapter.algo_data = smbus;
393 
394 	/* set up the sysfs linkage to our parent device */
395 	smbus->adapter.dev.parent = &dev->dev;
396 
397 	pci_write_config_dword(smbus->dev, AMD_PCI_MISC, 0);
398 	error = i2c_add_adapter(&smbus->adapter);
399 	if (error)
400 		goto out_release_region;
401 
402 	pci_set_drvdata(dev, smbus);
403 	return 0;
404 
405  out_release_region:
406 	release_region(smbus->base, smbus->size);
407  out_kfree:
408 	kfree(smbus);
409 	return error;
410 }
411 
412 static void __devexit amd8111_remove(struct pci_dev *dev)
413 {
414 	struct amd_smbus *smbus = pci_get_drvdata(dev);
415 
416 	i2c_del_adapter(&smbus->adapter);
417 	release_region(smbus->base, smbus->size);
418 	kfree(smbus);
419 }
420 
421 static struct pci_driver amd8111_driver = {
422 	.name		= "amd8111_smbus2",
423 	.id_table	= amd8111_ids,
424 	.probe		= amd8111_probe,
425 	.remove		= __devexit_p(amd8111_remove),
426 };
427 
428 static int __init i2c_amd8111_init(void)
429 {
430 	return pci_register_driver(&amd8111_driver);
431 }
432 
433 static void __exit i2c_amd8111_exit(void)
434 {
435 	pci_unregister_driver(&amd8111_driver);
436 }
437 
438 module_init(i2c_amd8111_init);
439 module_exit(i2c_amd8111_exit);
440