2 Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
3 Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
4 Mark D. Studebaker <mdsxyz123@yahoo.com>
5 Copyright (C) 2005 - 2008 Jean Delvare <khali@linux-fr.org>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 Supports the following VIA south bridges:
25 Chip name PCI ID REV I2C block
28 VT82C686A 0x3057 0x30 no
29 VT82C686B 0x3057 0x40 yes
39 VX800/VX820 0x8353 yes
40 VX855/VX875 0x8409 yes
42 Note: we assume there can only be one device, with one SMBus interface.
45 #include <linux/module.h>
46 #include <linux/delay.h>
47 #include <linux/pci.h>
48 #include <linux/kernel.h>
49 #include <linux/stddef.h>
50 #include <linux/ioport.h>
51 #include <linux/i2c.h>
52 #include <linux/init.h>
53 #include <linux/acpi.h>
56 static struct pci_dev *vt596_pdev;
62 /* SMBus address offsets */
63 static unsigned short vt596_smba;
64 #define SMBHSTSTS (vt596_smba + 0)
65 #define SMBHSTCNT (vt596_smba + 2)
66 #define SMBHSTCMD (vt596_smba + 3)
67 #define SMBHSTADD (vt596_smba + 4)
68 #define SMBHSTDAT0 (vt596_smba + 5)
69 #define SMBHSTDAT1 (vt596_smba + 6)
70 #define SMBBLKDAT (vt596_smba + 7)
72 /* PCI Address Constants */
74 /* SMBus data in configuration space can be found in two places,
75 We try to select the better one */
77 static unsigned short SMBHSTCFG = 0xD2;
80 #define MAX_TIMEOUT 500
82 /* VT82C596 constants */
83 #define VT596_QUICK 0x00
84 #define VT596_BYTE 0x04
85 #define VT596_BYTE_DATA 0x08
86 #define VT596_WORD_DATA 0x0C
87 #define VT596_PROC_CALL 0x10
88 #define VT596_BLOCK_DATA 0x14
89 #define VT596_I2C_BLOCK_DATA 0x34
92 /* If force is set to anything different from 0, we forcibly enable the
95 module_param(force, bool, 0);
96 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
98 /* If force_addr is set to anything different from 0, we forcibly enable
99 the VT596 at the given address. VERY DANGEROUS! */
100 static u16 force_addr;
101 module_param(force_addr, ushort, 0);
102 MODULE_PARM_DESC(force_addr,
103 "Forcibly enable the SMBus at the given address. "
104 "EXTREMELY DANGEROUS!");
107 static struct pci_driver vt596_driver;
108 static struct i2c_adapter vt596_adapter;
110 #define FEATURE_I2CBLOCK (1<<0)
111 static unsigned int vt596_features;
114 static void vt596_dump_regs(const char *msg, u8 size)
116 dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
117 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
118 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
121 if (size == VT596_BLOCK_DATA
122 || size == VT596_I2C_BLOCK_DATA) {
125 dev_dbg(&vt596_adapter.dev, "BLK=");
126 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
127 printk("%02x,", inb_p(SMBBLKDAT));
129 dev_dbg(&vt596_adapter.dev, " ");
130 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
131 printk("%02x,", inb_p(SMBBLKDAT));
132 printk("%02x\n", inb_p(SMBBLKDAT));
136 static inline void vt596_dump_regs(const char *msg, u8 size) { }
139 /* Return -1 on error, 0 on success */
140 static int vt596_transaction(u8 size)
146 vt596_dump_regs("Transaction (pre)", size);
148 /* Make sure the SMBus host is ready to start transmitting */
149 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
150 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
151 "Resetting...\n", temp);
153 outb_p(temp, SMBHSTSTS);
154 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
155 dev_err(&vt596_adapter.dev, "SMBus reset failed! "
161 /* Start the transaction by setting bit 6 */
162 outb_p(0x40 | size, SMBHSTCNT);
164 /* We will always wait for a fraction of a second */
167 temp = inb_p(SMBHSTSTS);
168 } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
170 /* If the SMBus is still busy, we give up */
171 if (timeout == MAX_TIMEOUT) {
173 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
178 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
184 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
189 dev_dbg(&vt596_adapter.dev, "No response\n");
192 /* Resetting status register */
194 outb_p(temp, SMBHSTSTS);
196 vt596_dump_regs("Transaction (post)", size);
201 /* Return negative errno on error, 0 on success */
202 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
203 unsigned short flags, char read_write, u8 command,
204 int size, union i2c_smbus_data *data)
210 case I2C_SMBUS_QUICK:
214 if (read_write == I2C_SMBUS_WRITE)
215 outb_p(command, SMBHSTCMD);
218 case I2C_SMBUS_BYTE_DATA:
219 outb_p(command, SMBHSTCMD);
220 if (read_write == I2C_SMBUS_WRITE)
221 outb_p(data->byte, SMBHSTDAT0);
222 size = VT596_BYTE_DATA;
224 case I2C_SMBUS_WORD_DATA:
225 outb_p(command, SMBHSTCMD);
226 if (read_write == I2C_SMBUS_WRITE) {
227 outb_p(data->word & 0xff, SMBHSTDAT0);
228 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
230 size = VT596_WORD_DATA;
232 case I2C_SMBUS_PROC_CALL:
233 outb_p(command, SMBHSTCMD);
234 outb_p(data->word & 0xff, SMBHSTDAT0);
235 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
236 size = VT596_PROC_CALL;
238 case I2C_SMBUS_I2C_BLOCK_DATA:
239 if (!(vt596_features & FEATURE_I2CBLOCK))
240 goto exit_unsupported;
241 if (read_write == I2C_SMBUS_READ)
242 outb_p(data->block[0], SMBHSTDAT0);
244 case I2C_SMBUS_BLOCK_DATA:
245 outb_p(command, SMBHSTCMD);
246 if (read_write == I2C_SMBUS_WRITE) {
247 u8 len = data->block[0];
248 if (len > I2C_SMBUS_BLOCK_MAX)
249 len = I2C_SMBUS_BLOCK_MAX;
250 outb_p(len, SMBHSTDAT0);
251 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
252 for (i = 1; i <= len; i++)
253 outb_p(data->block[i], SMBBLKDAT);
255 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
256 VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
259 goto exit_unsupported;
262 outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
264 status = vt596_transaction(size);
268 if (size == VT596_PROC_CALL)
269 read_write = I2C_SMBUS_READ;
271 if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
276 case VT596_BYTE_DATA:
277 data->byte = inb_p(SMBHSTDAT0);
279 case VT596_WORD_DATA:
280 case VT596_PROC_CALL:
281 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
283 case VT596_I2C_BLOCK_DATA:
284 case VT596_BLOCK_DATA:
285 data->block[0] = inb_p(SMBHSTDAT0);
286 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
287 data->block[0] = I2C_SMBUS_BLOCK_MAX;
288 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
289 for (i = 1; i <= data->block[0]; i++)
290 data->block[i] = inb_p(SMBBLKDAT);
296 dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
301 static u32 vt596_func(struct i2c_adapter *adapter)
303 u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
304 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
305 I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
307 if (vt596_features & FEATURE_I2CBLOCK)
308 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
312 static const struct i2c_algorithm smbus_algorithm = {
313 .smbus_xfer = vt596_access,
314 .functionality = vt596_func,
317 static struct i2c_adapter vt596_adapter = {
318 .owner = THIS_MODULE,
319 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
320 .algo = &smbus_algorithm,
323 static int __devinit vt596_probe(struct pci_dev *pdev,
324 const struct pci_device_id *id)
329 /* Determine the address of the SMBus areas */
331 vt596_smba = force_addr & 0xfff0;
336 if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
337 !(vt596_smba & 0x0001)) {
338 /* try 2nd address and config reg. for 596 */
339 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
340 !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
341 (vt596_smba & 0x0001)) {
344 /* no matches at all */
345 dev_err(&pdev->dev, "Cannot configure "
346 "SMBus I/O Base address\n");
351 vt596_smba &= 0xfff0;
352 if (vt596_smba == 0) {
353 dev_err(&pdev->dev, "SMBus base address "
354 "uninitialized - upgrade BIOS or use "
355 "force_addr=0xaddr\n");
360 error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
364 if (!request_region(vt596_smba, 8, vt596_driver.name)) {
365 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
370 pci_read_config_byte(pdev, SMBHSTCFG, &temp);
371 /* If force_addr is set, we program the new address here. Just to make
372 sure, we disable the VT596 first. */
374 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
375 pci_write_config_word(pdev, id->driver_data, vt596_smba);
376 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
377 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
378 "address 0x%04x!\n", vt596_smba);
379 } else if (!(temp & 0x01)) {
381 /* NOTE: This assumes I/O space and other allocations
382 * WERE done by the Bios! Don't complain if your
383 * hardware does weird things after enabling this.
384 * :') Check for Bios updates before resorting to
387 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
388 dev_info(&pdev->dev, "Enabling SMBus device\n");
390 dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
391 "controller not enabled! - upgrade BIOS or "
398 dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
400 switch (pdev->device) {
401 case PCI_DEVICE_ID_VIA_CX700:
402 case PCI_DEVICE_ID_VIA_VX800:
403 case PCI_DEVICE_ID_VIA_VX855:
404 case PCI_DEVICE_ID_VIA_VX900:
405 case PCI_DEVICE_ID_VIA_8251:
406 case PCI_DEVICE_ID_VIA_8237:
407 case PCI_DEVICE_ID_VIA_8237A:
408 case PCI_DEVICE_ID_VIA_8237S:
409 case PCI_DEVICE_ID_VIA_8235:
410 case PCI_DEVICE_ID_VIA_8233A:
411 case PCI_DEVICE_ID_VIA_8233_0:
412 vt596_features |= FEATURE_I2CBLOCK;
414 case PCI_DEVICE_ID_VIA_82C686_4:
415 /* The VT82C686B (rev 0x40) does support I2C block
416 transactions, but the VT82C686A (rev 0x30) doesn't */
417 if (pdev->revision >= 0x40)
418 vt596_features |= FEATURE_I2CBLOCK;
422 vt596_adapter.dev.parent = &pdev->dev;
423 snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
424 "SMBus Via Pro adapter at %04x", vt596_smba);
426 vt596_pdev = pci_dev_get(pdev);
427 error = i2c_add_adapter(&vt596_adapter);
429 pci_dev_put(vt596_pdev);
434 /* Always return failure here. This is to allow other drivers to bind
435 * to this pci device. We don't really want to have control over the
436 * pci device, we only wanted to read as few register values from it.
441 release_region(vt596_smba, 8);
445 static DEFINE_PCI_DEVICE_TABLE(vt596_ids) = {
446 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
447 .driver_data = SMBBA1 },
448 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
449 .driver_data = SMBBA1 },
450 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
451 .driver_data = SMBBA1 },
452 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
453 .driver_data = SMBBA3 },
454 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
455 .driver_data = SMBBA3 },
456 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
457 .driver_data = SMBBA3 },
458 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
459 .driver_data = SMBBA3 },
460 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
461 .driver_data = SMBBA3 },
462 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
463 .driver_data = SMBBA3 },
464 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
465 .driver_data = SMBBA1 },
466 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
467 .driver_data = SMBBA3 },
468 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
469 .driver_data = SMBBA3 },
470 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
471 .driver_data = SMBBA3 },
472 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855),
473 .driver_data = SMBBA3 },
474 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX900),
475 .driver_data = SMBBA3 },
479 MODULE_DEVICE_TABLE(pci, vt596_ids);
481 static struct pci_driver vt596_driver = {
482 .name = "vt596_smbus",
483 .id_table = vt596_ids,
484 .probe = vt596_probe,
487 static int __init i2c_vt596_init(void)
489 return pci_register_driver(&vt596_driver);
493 static void __exit i2c_vt596_exit(void)
495 pci_unregister_driver(&vt596_driver);
496 if (vt596_pdev != NULL) {
497 i2c_del_adapter(&vt596_adapter);
498 release_region(vt596_smba, 8);
499 pci_dev_put(vt596_pdev);
504 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
505 "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
506 "Jean Delvare <khali@linux-fr.org>");
507 MODULE_DESCRIPTION("vt82c596 SMBus driver");
508 MODULE_LICENSE("GPL");
510 module_init(i2c_vt596_init);
511 module_exit(i2c_vt596_exit);