xref: /openbmc/linux/drivers/i2c/busses/i2c-sis5595.c (revision 7f1005dd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
4     Philip Edelbrock <phil@netroedge.com>
5 
6 */
7 
8 /* Note: we assume there can only be one SIS5595 with one SMBus interface */
9 
10 /*
11    Note: all have mfr. ID 0x1039.
12    SUPPORTED		PCI ID
13 	5595		0008
14 
15    Note: these chips contain a 0008 device which is incompatible with the
16          5595. We recognize these by the presence of the listed
17          "blacklist" PCI ID and refuse to load.
18 
19    NOT SUPPORTED	PCI ID		BLACKLIST PCI ID
20 	 540		0008		0540
21 	 550		0008		0550
22 	5513		0008		5511
23 	5581		0008		5597
24 	5582		0008		5597
25 	5597		0008		5597
26 	5598		0008		5597/5598
27 	 630		0008		0630
28 	 645		0008		0645
29 	 646		0008		0646
30 	 648		0008		0648
31 	 650		0008		0650
32 	 651		0008		0651
33 	 730		0008		0730
34 	 735		0008		0735
35 	 745		0008		0745
36 	 746		0008		0746
37 */
38 
39 /* TO DO:
40  * Add Block Transfers (ugly, but supported by the adapter)
41  * Add adapter resets
42  */
43 
44 #include <linux/kernel.h>
45 #include <linux/module.h>
46 #include <linux/delay.h>
47 #include <linux/pci.h>
48 #include <linux/ioport.h>
49 #include <linux/init.h>
50 #include <linux/i2c.h>
51 #include <linux/acpi.h>
52 #include <linux/io.h>
53 
54 static int blacklist[] = {
55 	PCI_DEVICE_ID_SI_540,
56 	PCI_DEVICE_ID_SI_550,
57 	PCI_DEVICE_ID_SI_630,
58 	PCI_DEVICE_ID_SI_645,
59 	PCI_DEVICE_ID_SI_646,
60 	PCI_DEVICE_ID_SI_648,
61 	PCI_DEVICE_ID_SI_650,
62 	PCI_DEVICE_ID_SI_651,
63 	PCI_DEVICE_ID_SI_730,
64 	PCI_DEVICE_ID_SI_735,
65 	PCI_DEVICE_ID_SI_745,
66 	PCI_DEVICE_ID_SI_746,
67 	PCI_DEVICE_ID_SI_5511,	/* 5513 chip has the 0008 device but that ID
68 				   shows up in other chips so we use the 5511
69 				   ID for recognition */
70 	PCI_DEVICE_ID_SI_5597,
71 	PCI_DEVICE_ID_SI_5598,
72 	0,			/* terminates the list */
73 };
74 
75 /* Length of ISA address segment */
76 #define SIS5595_EXTENT		8
77 /* SIS5595 SMBus registers */
78 #define SMB_STS_LO		0x00
79 #define SMB_STS_HI		0x01
80 #define SMB_CTL_LO		0x02
81 #define SMB_CTL_HI		0x03
82 #define SMB_ADDR		0x04
83 #define SMB_CMD			0x05
84 #define SMB_PCNT		0x06
85 #define SMB_CNT			0x07
86 #define SMB_BYTE		0x08
87 #define SMB_DEV			0x10
88 #define SMB_DB0			0x11
89 #define SMB_DB1			0x12
90 #define SMB_HAA			0x13
91 
92 /* PCI Address Constants */
93 #define SMB_INDEX		0x38
94 #define SMB_DAT			0x39
95 #define SIS5595_ENABLE_REG	0x40
96 #define ACPI_BASE		0x90
97 
98 /* Other settings */
99 #define MAX_TIMEOUT		500
100 
101 /* SIS5595 constants */
102 #define SIS5595_QUICK		0x00
103 #define SIS5595_BYTE		0x02
104 #define SIS5595_BYTE_DATA	0x04
105 #define SIS5595_WORD_DATA	0x06
106 #define SIS5595_PROC_CALL	0x08
107 #define SIS5595_BLOCK_DATA	0x0A
108 
109 /* insmod parameters */
110 
111 /* If force_addr is set to anything different from 0, we forcibly enable
112    the device at the given address. */
113 static u16 force_addr;
114 module_param_hw(force_addr, ushort, ioport, 0);
115 MODULE_PARM_DESC(force_addr, "Initialize the base address of the i2c controller");
116 
117 static struct pci_driver sis5595_driver;
118 static unsigned short sis5595_base;
119 static struct pci_dev *sis5595_pdev;
120 
121 static u8 sis5595_read(u8 reg)
122 {
123 	outb(reg, sis5595_base + SMB_INDEX);
124 	return inb(sis5595_base + SMB_DAT);
125 }
126 
127 static void sis5595_write(u8 reg, u8 data)
128 {
129 	outb(reg, sis5595_base + SMB_INDEX);
130 	outb(data, sis5595_base + SMB_DAT);
131 }
132 
133 static int sis5595_setup(struct pci_dev *SIS5595_dev)
134 {
135 	u16 a;
136 	u8 val;
137 	int *i;
138 	int retval;
139 
140 	/* Look for imposters */
141 	for (i = blacklist; *i != 0; i++) {
142 		struct pci_dev *dev;
143 		dev = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
144 		if (dev) {
145 			dev_err(&SIS5595_dev->dev, "Looked for SIS5595 but found unsupported device %.4x\n", *i);
146 			pci_dev_put(dev);
147 			return -ENODEV;
148 		}
149 	}
150 
151 	/* Determine the address of the SMBus areas */
152 	pci_read_config_word(SIS5595_dev, ACPI_BASE, &sis5595_base);
153 	if (sis5595_base == 0 && force_addr == 0) {
154 		dev_err(&SIS5595_dev->dev, "ACPI base address uninitialized - upgrade BIOS or use force_addr=0xaddr\n");
155 		return -ENODEV;
156 	}
157 
158 	if (force_addr)
159 		sis5595_base = force_addr & ~(SIS5595_EXTENT - 1);
160 	dev_dbg(&SIS5595_dev->dev, "ACPI Base address: %04x\n", sis5595_base);
161 
162 	/* NB: We grab just the two SMBus registers here, but this may still
163 	 * interfere with ACPI :-(  */
164 	retval = acpi_check_region(sis5595_base + SMB_INDEX, 2,
165 				   sis5595_driver.name);
166 	if (retval)
167 		return retval;
168 
169 	if (!request_region(sis5595_base + SMB_INDEX, 2,
170 			    sis5595_driver.name)) {
171 		dev_err(&SIS5595_dev->dev, "SMBus registers 0x%04x-0x%04x already in use!\n",
172 			sis5595_base + SMB_INDEX, sis5595_base + SMB_INDEX + 1);
173 		return -ENODEV;
174 	}
175 
176 	if (force_addr) {
177 		dev_info(&SIS5595_dev->dev, "forcing ISA address 0x%04X\n", sis5595_base);
178 		retval = pci_write_config_word(SIS5595_dev, ACPI_BASE, sis5595_base);
179 		if (retval != PCIBIOS_SUCCESSFUL)
180 			goto error;
181 		retval = pci_read_config_word(SIS5595_dev, ACPI_BASE, &a);
182 		if (retval != PCIBIOS_SUCCESSFUL)
183 			goto error;
184 		if ((a & ~(SIS5595_EXTENT - 1)) != sis5595_base) {
185 			/* doesn't work for some chips! */
186 			dev_err(&SIS5595_dev->dev, "force address failed - not supported?\n");
187 			goto error;
188 		}
189 	}
190 
191 	retval = pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val);
192 	if (retval != PCIBIOS_SUCCESSFUL)
193 		goto error;
194 	if ((val & 0x80) == 0) {
195 		dev_info(&SIS5595_dev->dev, "enabling ACPI\n");
196 		retval = pci_write_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, val | 0x80);
197 		if (retval != PCIBIOS_SUCCESSFUL)
198 			goto error;
199 		retval = pci_read_config_byte(SIS5595_dev, SIS5595_ENABLE_REG, &val);
200 		if (retval != PCIBIOS_SUCCESSFUL)
201 			goto error;
202 		if ((val & 0x80) == 0) {
203 			/* doesn't work for some chips? */
204 			dev_err(&SIS5595_dev->dev, "ACPI enable failed - not supported?\n");
205 			goto error;
206 		}
207 	}
208 
209 	/* Everything is happy */
210 	return 0;
211 
212 error:
213 	release_region(sis5595_base + SMB_INDEX, 2);
214 	return -ENODEV;
215 }
216 
217 static int sis5595_transaction(struct i2c_adapter *adap)
218 {
219 	int temp;
220 	int result = 0;
221 	int timeout = 0;
222 
223 	/* Make sure the SMBus host is ready to start transmitting */
224 	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
225 	if (temp != 0x00) {
226 		dev_dbg(&adap->dev, "SMBus busy (%04x). Resetting...\n", temp);
227 		sis5595_write(SMB_STS_LO, temp & 0xff);
228 		sis5595_write(SMB_STS_HI, temp >> 8);
229 		if ((temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8)) != 0x00) {
230 			dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
231 			return -EBUSY;
232 		} else {
233 			dev_dbg(&adap->dev, "Successful!\n");
234 		}
235 	}
236 
237 	/* start the transaction by setting bit 4 */
238 	sis5595_write(SMB_CTL_LO, sis5595_read(SMB_CTL_LO) | 0x10);
239 
240 	/* We will always wait for a fraction of a second! */
241 	do {
242 		msleep(1);
243 		temp = sis5595_read(SMB_STS_LO);
244 	} while (!(temp & 0x40) && (timeout++ < MAX_TIMEOUT));
245 
246 	/* If the SMBus is still busy, we give up */
247 	if (timeout > MAX_TIMEOUT) {
248 		dev_dbg(&adap->dev, "SMBus Timeout!\n");
249 		result = -ETIMEDOUT;
250 	}
251 
252 	if (temp & 0x10) {
253 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
254 		result = -ENXIO;
255 	}
256 
257 	if (temp & 0x20) {
258 		dev_err(&adap->dev, "Bus collision! SMBus may be locked until "
259 			"next hard reset (or not...)\n");
260 		/* Clock stops and slave is stuck in mid-transmission */
261 		result = -EIO;
262 	}
263 
264 	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
265 	if (temp != 0x00) {
266 		sis5595_write(SMB_STS_LO, temp & 0xff);
267 		sis5595_write(SMB_STS_HI, temp >> 8);
268 	}
269 
270 	temp = sis5595_read(SMB_STS_LO) + (sis5595_read(SMB_STS_HI) << 8);
271 	if (temp != 0x00)
272 		dev_dbg(&adap->dev, "Failed reset at end of transaction (%02x)\n", temp);
273 
274 	return result;
275 }
276 
277 /* Return negative errno on error. */
278 static s32 sis5595_access(struct i2c_adapter *adap, u16 addr,
279 			  unsigned short flags, char read_write,
280 			  u8 command, int size, union i2c_smbus_data *data)
281 {
282 	int status;
283 
284 	switch (size) {
285 	case I2C_SMBUS_QUICK:
286 		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
287 		size = SIS5595_QUICK;
288 		break;
289 	case I2C_SMBUS_BYTE:
290 		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
291 		if (read_write == I2C_SMBUS_WRITE)
292 			sis5595_write(SMB_CMD, command);
293 		size = SIS5595_BYTE;
294 		break;
295 	case I2C_SMBUS_BYTE_DATA:
296 		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
297 		sis5595_write(SMB_CMD, command);
298 		if (read_write == I2C_SMBUS_WRITE)
299 			sis5595_write(SMB_BYTE, data->byte);
300 		size = SIS5595_BYTE_DATA;
301 		break;
302 	case I2C_SMBUS_PROC_CALL:
303 	case I2C_SMBUS_WORD_DATA:
304 		sis5595_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
305 		sis5595_write(SMB_CMD, command);
306 		if (read_write == I2C_SMBUS_WRITE) {
307 			sis5595_write(SMB_BYTE, data->word & 0xff);
308 			sis5595_write(SMB_BYTE + 1,
309 				      (data->word & 0xff00) >> 8);
310 		}
311 		size = (size == I2C_SMBUS_PROC_CALL) ? SIS5595_PROC_CALL : SIS5595_WORD_DATA;
312 		break;
313 	default:
314 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
315 		return -EOPNOTSUPP;
316 	}
317 
318 	sis5595_write(SMB_CTL_LO, ((size & 0x0E)));
319 
320 	status = sis5595_transaction(adap);
321 	if (status)
322 		return status;
323 
324 	if ((size != SIS5595_PROC_CALL) &&
325 	    ((read_write == I2C_SMBUS_WRITE) || (size == SIS5595_QUICK)))
326 		return 0;
327 
328 
329 	switch (size) {
330 	case SIS5595_BYTE:
331 	case SIS5595_BYTE_DATA:
332 		data->byte = sis5595_read(SMB_BYTE);
333 		break;
334 	case SIS5595_WORD_DATA:
335 	case SIS5595_PROC_CALL:
336 		data->word = sis5595_read(SMB_BYTE) + (sis5595_read(SMB_BYTE + 1) << 8);
337 		break;
338 	}
339 	return 0;
340 }
341 
342 static u32 sis5595_func(struct i2c_adapter *adapter)
343 {
344 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
345 	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
346 	    I2C_FUNC_SMBUS_PROC_CALL;
347 }
348 
349 static const struct i2c_algorithm smbus_algorithm = {
350 	.smbus_xfer	= sis5595_access,
351 	.functionality	= sis5595_func,
352 };
353 
354 static struct i2c_adapter sis5595_adapter = {
355 	.owner		= THIS_MODULE,
356 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
357 	.algo		= &smbus_algorithm,
358 };
359 
360 static const struct pci_device_id sis5595_ids[] = {
361 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
362 	{ 0, }
363 };
364 
365 MODULE_DEVICE_TABLE (pci, sis5595_ids);
366 
367 static int sis5595_probe(struct pci_dev *dev, const struct pci_device_id *id)
368 {
369 	int err;
370 
371 	if (sis5595_setup(dev)) {
372 		dev_err(&dev->dev, "SIS5595 not detected, module not inserted.\n");
373 		return -ENODEV;
374 	}
375 
376 	/* set up the sysfs linkage to our parent device */
377 	sis5595_adapter.dev.parent = &dev->dev;
378 
379 	snprintf(sis5595_adapter.name, sizeof(sis5595_adapter.name),
380 		 "SMBus SIS5595 adapter at %04x", sis5595_base + SMB_INDEX);
381 	err = i2c_add_adapter(&sis5595_adapter);
382 	if (err) {
383 		release_region(sis5595_base + SMB_INDEX, 2);
384 		return err;
385 	}
386 
387 	/* Always return failure here.  This is to allow other drivers to bind
388 	 * to this pci device.  We don't really want to have control over the
389 	 * pci device, we only wanted to read as few register values from it.
390 	 */
391 	sis5595_pdev =  pci_dev_get(dev);
392 	return -ENODEV;
393 }
394 
395 static struct pci_driver sis5595_driver = {
396 	.name		= "sis5595_smbus",
397 	.id_table	= sis5595_ids,
398 	.probe		= sis5595_probe,
399 };
400 
401 static int __init i2c_sis5595_init(void)
402 {
403 	return pci_register_driver(&sis5595_driver);
404 }
405 
406 static void __exit i2c_sis5595_exit(void)
407 {
408 	pci_unregister_driver(&sis5595_driver);
409 	if (sis5595_pdev) {
410 		i2c_del_adapter(&sis5595_adapter);
411 		release_region(sis5595_base + SMB_INDEX, 2);
412 		pci_dev_put(sis5595_pdev);
413 		sis5595_pdev = NULL;
414 	}
415 }
416 
417 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
418 MODULE_DESCRIPTION("SIS5595 SMBus driver");
419 MODULE_LICENSE("GPL");
420 
421 module_init(i2c_sis5595_init);
422 module_exit(i2c_sis5595_exit);
423