xref: /linux/drivers/i2c/busses/i2c-ali1563.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 		/* Issue 'kill' to host controller */
103 		outb_p(HST_CNTL2_KILL, SMB_HST_CNTL2);
104 		data = inb_p(SMB_HST_STS);
105 		status = -ETIMEDOUT;
106 	}
107 
108 	/* device error - no response, ignore the autodetection case */
109 	if (data & HST_STS_DEVERR) {
110 		if (size != HST_CNTL2_QUICK)
111 			dev_err(&a->dev, "Device error!\n");
112 		status = -ENXIO;
113 	}
114 	/* bus collision */
115 	if (data & HST_STS_BUSERR) {
116 		dev_err(&a->dev, "Bus collision!\n");
117 		/* Issue timeout, hoping it helps */
118 		outb_p(HST_CNTL1_TIMEOUT, SMB_HST_CNTL1);
119 	}
120 
121 	if (data & HST_STS_FAIL) {
122 		dev_err(&a->dev, "Cleaning fail after KILL!\n");
123 		outb_p(0x0, SMB_HST_CNTL2);
124 	}
125 
126 	return status;
127 }
128 
129 static int ali1563_block_start(struct i2c_adapter *a)
130 {
131 	u32 data;
132 	int timeout;
133 	int status = -EIO;
134 
135 	dev_dbg(&a->dev, "Block (pre): STS=%02x, CNTL1=%02x, "
136 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
137 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
138 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
139 		inb_p(SMB_HST_DAT1));
140 
141 	data = inb_p(SMB_HST_STS);
142 	if (data & HST_STS_BAD) {
143 		dev_warn(&a->dev, "ali1563: Trying to reset busy device\n");
144 		outb_p(data | HST_STS_BAD, SMB_HST_STS);
145 		data = inb_p(SMB_HST_STS);
146 		if (data & HST_STS_BAD)
147 			return -EBUSY;
148 	}
149 
150 	/* Clear byte-ready bit */
151 	outb_p(data | HST_STS_DONE, SMB_HST_STS);
152 
153 	/* Start transaction and wait for byte-ready bit to be set */
154 	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);
155 
156 	timeout = ALI1563_MAX_TIMEOUT;
157 	do {
158 		msleep(1);
159 	} while (!((data = inb_p(SMB_HST_STS)) & HST_STS_DONE) && --timeout);
160 
161 	dev_dbg(&a->dev, "Block (post): STS=%02x, CNTL1=%02x, "
162 		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
163 		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
164 		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
165 		inb_p(SMB_HST_DAT1));
166 
167 	if (timeout && !(data & HST_STS_BAD))
168 		return 0;
169 
170 	if (timeout == 0)
171 		status = -ETIMEDOUT;
172 
173 	if (data & HST_STS_DEVERR)
174 		status = -ENXIO;
175 
176 	dev_err(&a->dev, "SMBus Error: %s%s%s%s%s\n",
177 		timeout ? "" : "Timeout ",
178 		data & HST_STS_FAIL ? "Transaction Failed " : "",
179 		data & HST_STS_BUSERR ? "No response or Bus Collision " : "",
180 		data & HST_STS_DEVERR ? "Device Error " : "",
181 		!(data & HST_STS_DONE) ? "Transaction Never Finished " : "");
182 	return status;
183 }
184 
185 static int ali1563_block(struct i2c_adapter *a,
186 			 union i2c_smbus_data *data, u8 rw)
187 {
188 	int i, len;
189 	int error = 0;
190 
191 	/* Do we need this? */
192 	outb_p(HST_CNTL1_LAST, SMB_HST_CNTL1);
193 
194 	if (rw == I2C_SMBUS_WRITE) {
195 		len = data->block[0];
196 		if (len < 1)
197 			len = 1;
198 		else if (len > 32)
199 			len = 32;
200 		outb_p(len, SMB_HST_DAT0);
201 		outb_p(data->block[1], SMB_BLK_DAT);
202 	} else
203 		len = 32;
204 
205 	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_BLOCK, SMB_HST_CNTL2);
206 
207 	for (i = 0; i < len; i++) {
208 		if (rw == I2C_SMBUS_WRITE) {
209 			outb_p(data->block[i + 1], SMB_BLK_DAT);
210 			error = ali1563_block_start(a);
211 			if (error)
212 				break;
213 		} else {
214 			error = ali1563_block_start(a);
215 			if (error)
216 				break;
217 			if (i == 0) {
218 				len = inb_p(SMB_HST_DAT0);
219 				if (len < 1)
220 					len = 1;
221 				else if (len > 32)
222 					len = 32;
223 			}
224 			data->block[i+1] = inb_p(SMB_BLK_DAT);
225 		}
226 	}
227 	/* Do we need this? */
228 	outb_p(HST_CNTL1_LAST, SMB_HST_CNTL1);
229 	return error;
230 }
231 
232 static s32 ali1563_access(struct i2c_adapter *a, u16 addr,
233 			  unsigned short flags, char rw, u8 cmd,
234 			  int size, union i2c_smbus_data *data)
235 {
236 	int error = 0;
237 	int timeout;
238 	u32 reg;
239 
240 	for (timeout = ALI1563_MAX_TIMEOUT; timeout; timeout--) {
241 		reg = inb_p(SMB_HST_STS);
242 		if (!(reg & HST_STS_BUSY))
243 			break;
244 	}
245 	if (!timeout)
246 		dev_warn(&a->dev, "SMBus not idle. HST_STS = %02x\n", reg);
247 	outb_p(0xff, SMB_HST_STS);
248 
249 	/* Map the size to what the chip understands */
250 	switch (size) {
251 	case I2C_SMBUS_QUICK:
252 		size = HST_CNTL2_QUICK;
253 		break;
254 	case I2C_SMBUS_BYTE:
255 		size = HST_CNTL2_BYTE;
256 		break;
257 	case I2C_SMBUS_BYTE_DATA:
258 		size = HST_CNTL2_BYTE_DATA;
259 		break;
260 	case I2C_SMBUS_WORD_DATA:
261 		size = HST_CNTL2_WORD_DATA;
262 		break;
263 	case I2C_SMBUS_BLOCK_DATA:
264 		size = HST_CNTL2_BLOCK;
265 		break;
266 	default:
267 		dev_warn(&a->dev, "Unsupported transaction %d\n", size);
268 		error = -EOPNOTSUPP;
269 		goto Done;
270 	}
271 
272 	outb_p(((addr & 0x7f) << 1) | (rw & 0x01), SMB_HST_ADD);
273 	outb_p((inb_p(SMB_HST_CNTL2) & ~HST_CNTL2_SIZEMASK) |
274 	       (size << 3), SMB_HST_CNTL2);
275 
276 	/* Write the command register */
277 
278 	switch (size) {
279 	case HST_CNTL2_BYTE:
280 		if (rw == I2C_SMBUS_WRITE)
281 			/* Beware it uses DAT0 register and not CMD! */
282 			outb_p(cmd, SMB_HST_DAT0);
283 		break;
284 	case HST_CNTL2_BYTE_DATA:
285 		outb_p(cmd, SMB_HST_CMD);
286 		if (rw == I2C_SMBUS_WRITE)
287 			outb_p(data->byte, SMB_HST_DAT0);
288 		break;
289 	case HST_CNTL2_WORD_DATA:
290 		outb_p(cmd, SMB_HST_CMD);
291 		if (rw == I2C_SMBUS_WRITE) {
292 			outb_p(data->word & 0xff, SMB_HST_DAT0);
293 			outb_p((data->word & 0xff00) >> 8, SMB_HST_DAT1);
294 		}
295 		break;
296 	case HST_CNTL2_BLOCK:
297 		outb_p(cmd, SMB_HST_CMD);
298 		error = ali1563_block(a, data, rw);
299 		goto Done;
300 	}
301 
302 	error = ali1563_transaction(a, size);
303 	if (error)
304 		goto Done;
305 
306 	if ((rw == I2C_SMBUS_WRITE) || (size == HST_CNTL2_QUICK))
307 		goto Done;
308 
309 	switch (size) {
310 	case HST_CNTL2_BYTE:	/* Result put in SMBHSTDAT0 */
311 		data->byte = inb_p(SMB_HST_DAT0);
312 		break;
313 	case HST_CNTL2_BYTE_DATA:
314 		data->byte = inb_p(SMB_HST_DAT0);
315 		break;
316 	case HST_CNTL2_WORD_DATA:
317 		data->word = inb_p(SMB_HST_DAT0) + (inb_p(SMB_HST_DAT1) << 8);
318 		break;
319 	}
320 Done:
321 	return error;
322 }
323 
324 static u32 ali1563_func(struct i2c_adapter *a)
325 {
326 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
327 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
328 	    I2C_FUNC_SMBUS_BLOCK_DATA;
329 }
330 
331 
332 static int ali1563_setup(struct pci_dev *dev)
333 {
334 	u16 ctrl;
335 
336 	pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
337 
338 	/* SMB I/O Base in high 12 bits and must be aligned with the
339 	 * size of the I/O space. */
340 	ali1563_smba = ctrl & ~(ALI1563_SMB_IOSIZE - 1);
341 	if (!ali1563_smba) {
342 		dev_warn(&dev->dev, "ali1563_smba Uninitialized\n");
343 		goto Err;
344 	}
345 
346 	/* Check if device is enabled */
347 	if (!(ctrl & ALI1563_SMB_HOSTEN)) {
348 		dev_warn(&dev->dev, "Host Controller not enabled\n");
349 		goto Err;
350 	}
351 	if (!(ctrl & ALI1563_SMB_IOEN)) {
352 		dev_warn(&dev->dev, "I/O space not enabled, trying manually\n");
353 		pci_write_config_word(dev, ALI1563_SMBBA,
354 				      ctrl | ALI1563_SMB_IOEN);
355 		pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
356 		if (!(ctrl & ALI1563_SMB_IOEN)) {
357 			dev_err(&dev->dev,
358 				"I/O space still not enabled, giving up\n");
359 			goto Err;
360 		}
361 	}
362 
363 	if (acpi_check_region(ali1563_smba, ALI1563_SMB_IOSIZE,
364 			      ali1563_pci_driver.name))
365 		goto Err;
366 
367 	if (!request_region(ali1563_smba, ALI1563_SMB_IOSIZE,
368 			    ali1563_pci_driver.name)) {
369 		dev_err(&dev->dev, "Could not allocate I/O space at 0x%04x\n",
370 			ali1563_smba);
371 		goto Err;
372 	}
373 	dev_info(&dev->dev, "Found ALi1563 SMBus at 0x%04x\n", ali1563_smba);
374 
375 	return 0;
376 Err:
377 	return -ENODEV;
378 }
379 
380 static void ali1563_shutdown(struct pci_dev *dev)
381 {
382 	release_region(ali1563_smba, ALI1563_SMB_IOSIZE);
383 }
384 
385 static const struct i2c_algorithm ali1563_algorithm = {
386 	.smbus_xfer	= ali1563_access,
387 	.functionality	= ali1563_func,
388 };
389 
390 static struct i2c_adapter ali1563_adapter = {
391 	.owner	= THIS_MODULE,
392 	.class	= I2C_CLASS_HWMON,
393 	.algo	= &ali1563_algorithm,
394 };
395 
396 static int ali1563_probe(struct pci_dev *dev,
397 			 const struct pci_device_id *id_table)
398 {
399 	int error;
400 
401 	error = ali1563_setup(dev);
402 	if (error)
403 		goto exit;
404 	ali1563_adapter.dev.parent = &dev->dev;
405 	snprintf(ali1563_adapter.name, sizeof(ali1563_adapter.name),
406 		 "SMBus ALi 1563 Adapter @ %04x", ali1563_smba);
407 	error = i2c_add_adapter(&ali1563_adapter);
408 	if (error)
409 		goto exit_shutdown;
410 	return 0;
411 
412 exit_shutdown:
413 	ali1563_shutdown(dev);
414 exit:
415 	dev_warn(&dev->dev, "ALi1563 SMBus probe failed (%d)\n", error);
416 	return error;
417 }
418 
419 static void ali1563_remove(struct pci_dev *dev)
420 {
421 	i2c_del_adapter(&ali1563_adapter);
422 	ali1563_shutdown(dev);
423 }
424 
425 static const struct pci_device_id ali1563_id_table[] = {
426 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1563) },
427 	{},
428 };
429 
430 MODULE_DEVICE_TABLE(pci, ali1563_id_table);
431 
432 static struct pci_driver ali1563_pci_driver = {
433 	.name		= "ali1563_smbus",
434 	.id_table	= ali1563_id_table,
435 	.probe		= ali1563_probe,
436 	.remove		= ali1563_remove,
437 };
438 
439 module_pci_driver(ali1563_pci_driver);
440 
441 MODULE_DESCRIPTION("i2c driver for the ALi 1563 Southbridge");
442 MODULE_LICENSE("GPL");
443