xref: /openbmc/linux/drivers/i2c/busses/i2c-ali1563.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	i2c-ali1563.c - i2c driver for the ALi 1563 Southbridge
4  *
5  *	Copyright (C) 2004 Patrick Mochel
6  *		      2005 Rudolf Marek <r.marek@assembler.cz>
7  *
8  *	The 1563 southbridge is deceptively similar to the 1533, with a
9  *	few notable exceptions. One of those happens to be the fact they
10  *	upgraded the i2c core to be 2.0 compliant, and happens to be almost
11  *	identical to the i2c controller found in the Intel 801 south
12  *	bridges.
13  *
14  *	This driver is based on a mix of the 15x3, 1535, and i801 drivers,
15  *	with a little help from the ALi 1563 spec.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/i2c.h>
21 #include <linux/pci.h>
22 #include <linux/acpi.h>
23 
24 #define ALI1563_MAX_TIMEOUT	500
25 #define	ALI1563_SMBBA		0x80
26 #define ALI1563_SMB_IOEN	1
27 #define ALI1563_SMB_HOSTEN	2
28 #define ALI1563_SMB_IOSIZE	16
29 
30 #define SMB_HST_STS	(ali1563_smba + 0)
31 #define SMB_HST_CNTL1	(ali1563_smba + 1)
32 #define SMB_HST_CNTL2	(ali1563_smba + 2)
33 #define SMB_HST_CMD	(ali1563_smba + 3)
34 #define SMB_HST_ADD	(ali1563_smba + 4)
35 #define SMB_HST_DAT0	(ali1563_smba + 5)
36 #define SMB_HST_DAT1	(ali1563_smba + 6)
37 #define SMB_BLK_DAT	(ali1563_smba + 7)
38 
39 #define HST_STS_BUSY	0x01
40 #define HST_STS_INTR	0x02
41 #define HST_STS_DEVERR	0x04
42 #define HST_STS_BUSERR	0x08
43 #define HST_STS_FAIL	0x10
44 #define HST_STS_DONE	0x80
45 #define HST_STS_BAD	0x1c
46 
47 
48 #define HST_CNTL1_TIMEOUT	0x80
49 #define HST_CNTL1_LAST		0x40
50 
51 #define HST_CNTL2_KILL		0x04
52 #define HST_CNTL2_START		0x40
53 #define HST_CNTL2_QUICK		0x00
54 #define HST_CNTL2_BYTE		0x01
55 #define HST_CNTL2_BYTE_DATA	0x02
56 #define HST_CNTL2_WORD_DATA	0x03
57 #define HST_CNTL2_BLOCK		0x05
58 
59 
60 #define HST_CNTL2_SIZEMASK	0x38
61 
62 static struct pci_driver ali1563_pci_driver;
63 static unsigned short ali1563_smba;
64 
65 static int ali1563_transaction(struct i2c_adapter *a, int size)
66 {
67 	u32 data;
68 	int timeout;
69 	int status = -EIO;
70 
71 	dev_dbg(&a->dev, "Transaction (pre): STS=%02x, CNTL1=%02x, "
72 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
73 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
74 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
75 		inb_p(SMB_HST_DAT1));
76 
77 	data = inb_p(SMB_HST_STS);
78 	if (data & HST_STS_BAD) {
79 		dev_err(&a->dev, "ali1563: Trying to reset busy device\n");
80 		outb_p(data | HST_STS_BAD, SMB_HST_STS);
81 		data = inb_p(SMB_HST_STS);
82 		if (data & HST_STS_BAD)
83 			return -EBUSY;
84 	}
85 	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);
86 
87 	timeout = ALI1563_MAX_TIMEOUT;
88 	do {
89 		msleep(1);
90 	} while (((data = inb_p(SMB_HST_STS)) & HST_STS_BUSY) && --timeout);
91 
92 	dev_dbg(&a->dev, "Transaction (post): STS=%02x, CNTL1=%02x, "
93 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
94 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
95 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
96 		inb_p(SMB_HST_DAT1));
97 
98 	if (timeout && !(data & HST_STS_BAD))
99 		return 0;
100 
101 	if (!timeout) {
102 		dev_err(&a->dev, "Timeout - Trying to KILL transaction!\n");
103 		/* Issue 'kill' to host controller */
104 		outb_p(HST_CNTL2_KILL, SMB_HST_CNTL2);
105 		data = inb_p(SMB_HST_STS);
106 		status = -ETIMEDOUT;
107 	}
108 
109 	/* device error - no response, ignore the autodetection case */
110 	if (data & HST_STS_DEVERR) {
111 		if (size != HST_CNTL2_QUICK)
112 			dev_err(&a->dev, "Device error!\n");
113 		status = -ENXIO;
114 	}
115 	/* bus collision */
116 	if (data & HST_STS_BUSERR) {
117 		dev_err(&a->dev, "Bus collision!\n");
118 		/* Issue timeout, hoping it helps */
119 		outb_p(HST_CNTL1_TIMEOUT, SMB_HST_CNTL1);
120 	}
121 
122 	if (data & HST_STS_FAIL) {
123 		dev_err(&a->dev, "Cleaning fail after KILL!\n");
124 		outb_p(0x0, SMB_HST_CNTL2);
125 	}
126 
127 	return status;
128 }
129 
130 static int ali1563_block_start(struct i2c_adapter *a)
131 {
132 	u32 data;
133 	int timeout;
134 	int status = -EIO;
135 
136 	dev_dbg(&a->dev, "Block (pre): STS=%02x, CNTL1=%02x, "
137 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
138 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
139 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
140 		inb_p(SMB_HST_DAT1));
141 
142 	data = inb_p(SMB_HST_STS);
143 	if (data & HST_STS_BAD) {
144 		dev_warn(&a->dev, "ali1563: Trying to reset busy device\n");
145 		outb_p(data | HST_STS_BAD, SMB_HST_STS);
146 		data = inb_p(SMB_HST_STS);
147 		if (data & HST_STS_BAD)
148 			return -EBUSY;
149 	}
150 
151 	/* Clear byte-ready bit */
152 	outb_p(data | HST_STS_DONE, SMB_HST_STS);
153 
154 	/* Start transaction and wait for byte-ready bit to be set */
155 	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);
156 
157 	timeout = ALI1563_MAX_TIMEOUT;
158 	do {
159 		msleep(1);
160 	} while (!((data = inb_p(SMB_HST_STS)) & HST_STS_DONE) && --timeout);
161 
162 	dev_dbg(&a->dev, "Block (post): STS=%02x, CNTL1=%02x, "
163 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
164 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
165 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
166 		inb_p(SMB_HST_DAT1));
167 
168 	if (timeout && !(data & HST_STS_BAD))
169 		return 0;
170 
171 	if (timeout == 0)
172 		status = -ETIMEDOUT;
173 
174 	if (data & HST_STS_DEVERR)
175 		status = -ENXIO;
176 
177 	dev_err(&a->dev, "SMBus Error: %s%s%s%s%s\n",
178 		timeout ? "" : "Timeout ",
179 		data & HST_STS_FAIL ? "Transaction Failed " : "",
180 		data & HST_STS_BUSERR ? "No response or Bus Collision " : "",
181 		data & HST_STS_DEVERR ? "Device Error " : "",
182 		!(data & HST_STS_DONE) ? "Transaction Never Finished " : "");
183 	return status;
184 }
185 
186 static int ali1563_block(struct i2c_adapter *a,
187 			 union i2c_smbus_data *data, u8 rw)
188 {
189 	int i, len;
190 	int error = 0;
191 
192 	/* Do we need this? */
193 	outb_p(HST_CNTL1_LAST, SMB_HST_CNTL1);
194 
195 	if (rw == I2C_SMBUS_WRITE) {
196 		len = data->block[0];
197 		if (len < 1)
198 			len = 1;
199 		else if (len > 32)
200 			len = 32;
201 		outb_p(len, SMB_HST_DAT0);
202 		outb_p(data->block[1], SMB_BLK_DAT);
203 	} else
204 		len = 32;
205 
206 	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_BLOCK, SMB_HST_CNTL2);
207 
208 	for (i = 0; i < len; i++) {
209 		if (rw == I2C_SMBUS_WRITE) {
210 			outb_p(data->block[i + 1], SMB_BLK_DAT);
211 			error = ali1563_block_start(a);
212 			if (error)
213 				break;
214 		} else {
215 			error = ali1563_block_start(a);
216 			if (error)
217 				break;
218 			if (i == 0) {
219 				len = inb_p(SMB_HST_DAT0);
220 				if (len < 1)
221 					len = 1;
222 				else if (len > 32)
223 					len = 32;
224 			}
225 			data->block[i+1] = inb_p(SMB_BLK_DAT);
226 		}
227 	}
228 	/* Do we need this? */
229 	outb_p(HST_CNTL1_LAST, SMB_HST_CNTL1);
230 	return error;
231 }
232 
233 static s32 ali1563_access(struct i2c_adapter *a, u16 addr,
234 			  unsigned short flags, char rw, u8 cmd,
235 			  int size, union i2c_smbus_data *data)
236 {
237 	int error = 0;
238 	int timeout;
239 	u32 reg;
240 
241 	for (timeout = ALI1563_MAX_TIMEOUT; timeout; timeout--) {
242 		reg = inb_p(SMB_HST_STS);
243 		if (!(reg & HST_STS_BUSY))
244 			break;
245 	}
246 	if (!timeout)
247 		dev_warn(&a->dev, "SMBus not idle. HST_STS = %02x\n", reg);
248 	outb_p(0xff, SMB_HST_STS);
249 
250 	/* Map the size to what the chip understands */
251 	switch (size) {
252 	case I2C_SMBUS_QUICK:
253 		size = HST_CNTL2_QUICK;
254 		break;
255 	case I2C_SMBUS_BYTE:
256 		size = HST_CNTL2_BYTE;
257 		break;
258 	case I2C_SMBUS_BYTE_DATA:
259 		size = HST_CNTL2_BYTE_DATA;
260 		break;
261 	case I2C_SMBUS_WORD_DATA:
262 		size = HST_CNTL2_WORD_DATA;
263 		break;
264 	case I2C_SMBUS_BLOCK_DATA:
265 		size = HST_CNTL2_BLOCK;
266 		break;
267 	default:
268 		dev_warn(&a->dev, "Unsupported transaction %d\n", size);
269 		error = -EOPNOTSUPP;
270 		goto Done;
271 	}
272 
273 	outb_p(((addr & 0x7f) << 1) | (rw & 0x01), SMB_HST_ADD);
274 	outb_p((inb_p(SMB_HST_CNTL2) & ~HST_CNTL2_SIZEMASK) |
275 	       (size << 3), SMB_HST_CNTL2);
276 
277 	/* Write the command register */
278 
279 	switch (size) {
280 	case HST_CNTL2_BYTE:
281 		if (rw == I2C_SMBUS_WRITE)
282 			/* Beware it uses DAT0 register and not CMD! */
283 			outb_p(cmd, SMB_HST_DAT0);
284 		break;
285 	case HST_CNTL2_BYTE_DATA:
286 		outb_p(cmd, SMB_HST_CMD);
287 		if (rw == I2C_SMBUS_WRITE)
288 			outb_p(data->byte, SMB_HST_DAT0);
289 		break;
290 	case HST_CNTL2_WORD_DATA:
291 		outb_p(cmd, SMB_HST_CMD);
292 		if (rw == I2C_SMBUS_WRITE) {
293 			outb_p(data->word & 0xff, SMB_HST_DAT0);
294 			outb_p((data->word & 0xff00) >> 8, SMB_HST_DAT1);
295 		}
296 		break;
297 	case HST_CNTL2_BLOCK:
298 		outb_p(cmd, SMB_HST_CMD);
299 		error = ali1563_block(a, data, rw);
300 		goto Done;
301 	}
302 
303 	error = ali1563_transaction(a, size);
304 	if (error)
305 		goto Done;
306 
307 	if ((rw == I2C_SMBUS_WRITE) || (size == HST_CNTL2_QUICK))
308 		goto Done;
309 
310 	switch (size) {
311 	case HST_CNTL2_BYTE:	/* Result put in SMBHSTDAT0 */
312 		data->byte = inb_p(SMB_HST_DAT0);
313 		break;
314 	case HST_CNTL2_BYTE_DATA:
315 		data->byte = inb_p(SMB_HST_DAT0);
316 		break;
317 	case HST_CNTL2_WORD_DATA:
318 		data->word = inb_p(SMB_HST_DAT0) + (inb_p(SMB_HST_DAT1) << 8);
319 		break;
320 	}
321 Done:
322 	return error;
323 }
324 
325 static u32 ali1563_func(struct i2c_adapter *a)
326 {
327 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
328 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
329 	    I2C_FUNC_SMBUS_BLOCK_DATA;
330 }
331 
332 
333 static int ali1563_setup(struct pci_dev *dev)
334 {
335 	u16 ctrl;
336 
337 	pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
338 
339 	/* SMB I/O Base in high 12 bits and must be aligned with the
340 	 * size of the I/O space. */
341 	ali1563_smba = ctrl & ~(ALI1563_SMB_IOSIZE - 1);
342 	if (!ali1563_smba) {
343 		dev_warn(&dev->dev, "ali1563_smba Uninitialized\n");
344 		goto Err;
345 	}
346 
347 	/* Check if device is enabled */
348 	if (!(ctrl & ALI1563_SMB_HOSTEN)) {
349 		dev_warn(&dev->dev, "Host Controller not enabled\n");
350 		goto Err;
351 	}
352 	if (!(ctrl & ALI1563_SMB_IOEN)) {
353 		dev_warn(&dev->dev, "I/O space not enabled, trying manually\n");
354 		pci_write_config_word(dev, ALI1563_SMBBA,
355 				      ctrl | ALI1563_SMB_IOEN);
356 		pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
357 		if (!(ctrl & ALI1563_SMB_IOEN)) {
358 			dev_err(&dev->dev,
359 				"I/O space still not enabled, giving up\n");
360 			goto Err;
361 		}
362 	}
363 
364 	if (acpi_check_region(ali1563_smba, ALI1563_SMB_IOSIZE,
365 			      ali1563_pci_driver.name))
366 		goto Err;
367 
368 	if (!request_region(ali1563_smba, ALI1563_SMB_IOSIZE,
369 			    ali1563_pci_driver.name)) {
370 		dev_err(&dev->dev, "Could not allocate I/O space at 0x%04x\n",
371 			ali1563_smba);
372 		goto Err;
373 	}
374 	dev_info(&dev->dev, "Found ALi1563 SMBus at 0x%04x\n", ali1563_smba);
375 
376 	return 0;
377 Err:
378 	return -ENODEV;
379 }
380 
381 static void ali1563_shutdown(struct pci_dev *dev)
382 {
383 	release_region(ali1563_smba, ALI1563_SMB_IOSIZE);
384 }
385 
386 static const struct i2c_algorithm ali1563_algorithm = {
387 	.smbus_xfer	= ali1563_access,
388 	.functionality	= ali1563_func,
389 };
390 
391 static struct i2c_adapter ali1563_adapter = {
392 	.owner	= THIS_MODULE,
393 	.class	= I2C_CLASS_HWMON | I2C_CLASS_SPD,
394 	.algo	= &ali1563_algorithm,
395 };
396 
397 static int ali1563_probe(struct pci_dev *dev,
398 			 const struct pci_device_id *id_table)
399 {
400 	int error;
401 
402 	error = ali1563_setup(dev);
403 	if (error)
404 		goto exit;
405 	ali1563_adapter.dev.parent = &dev->dev;
406 	snprintf(ali1563_adapter.name, sizeof(ali1563_adapter.name),
407 		 "SMBus ALi 1563 Adapter @ %04x", ali1563_smba);
408 	error = i2c_add_adapter(&ali1563_adapter);
409 	if (error)
410 		goto exit_shutdown;
411 	return 0;
412 
413 exit_shutdown:
414 	ali1563_shutdown(dev);
415 exit:
416 	dev_warn(&dev->dev, "ALi1563 SMBus probe failed (%d)\n", error);
417 	return error;
418 }
419 
420 static void ali1563_remove(struct pci_dev *dev)
421 {
422 	i2c_del_adapter(&ali1563_adapter);
423 	ali1563_shutdown(dev);
424 }
425 
426 static const struct pci_device_id ali1563_id_table[] = {
427 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1563) },
428 	{},
429 };
430 
431 MODULE_DEVICE_TABLE(pci, ali1563_id_table);
432 
433 static struct pci_driver ali1563_pci_driver = {
434 	.name		= "ali1563_smbus",
435 	.id_table	= ali1563_id_table,
436 	.probe		= ali1563_probe,
437 	.remove		= ali1563_remove,
438 };
439 
440 module_pci_driver(ali1563_pci_driver);
441 
442 MODULE_LICENSE("GPL");
443