2 i2c-viapro.c - Part of lm_sensors, Linux kernel modules for hardware
4 Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
5 Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
6 Mark D. Studebaker <mdsxyz123@yahoo.com>
7 Copyright (C) 2005 - 2008 Jean Delvare <khali@linux-fr.org>
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 Supports the following VIA south bridges:
27 Chip name PCI ID REV I2C block
30 VT82C686A 0x3057 0x30 no
31 VT82C686B 0x3057 0x40 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_BLOCK_DATA 0x14
88 #define VT596_I2C_BLOCK_DATA 0x34
91 /* If force is set to anything different from 0, we forcibly enable the
94 module_param(force, bool, 0);
95 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
97 /* If force_addr is set to anything different from 0, we forcibly enable
98 the VT596 at the given address. VERY DANGEROUS! */
99 static u16 force_addr;
100 module_param(force_addr, ushort, 0);
101 MODULE_PARM_DESC(force_addr,
102 "Forcibly enable the SMBus at the given address. "
103 "EXTREMELY DANGEROUS!");
106 static struct pci_driver vt596_driver;
107 static struct i2c_adapter vt596_adapter;
109 #define FEATURE_I2CBLOCK (1<<0)
110 static unsigned int vt596_features;
113 static void vt596_dump_regs(const char *msg, u8 size)
115 dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
116 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
117 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
120 if (size == VT596_BLOCK_DATA
121 || size == VT596_I2C_BLOCK_DATA) {
124 dev_dbg(&vt596_adapter.dev, "BLK=");
125 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
126 printk("%02x,", inb_p(SMBBLKDAT));
128 dev_dbg(&vt596_adapter.dev, " ");
129 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
130 printk("%02x,", inb_p(SMBBLKDAT));
131 printk("%02x\n", inb_p(SMBBLKDAT));
135 static inline void vt596_dump_regs(const char *msg, u8 size) { }
138 /* Return -1 on error, 0 on success */
139 static int vt596_transaction(u8 size)
145 vt596_dump_regs("Transaction (pre)", size);
147 /* Make sure the SMBus host is ready to start transmitting */
148 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
149 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
150 "Resetting...\n", temp);
152 outb_p(temp, SMBHSTSTS);
153 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
154 dev_err(&vt596_adapter.dev, "SMBus reset failed! "
160 /* Start the transaction by setting bit 6 */
161 outb_p(0x40 | size, SMBHSTCNT);
163 /* We will always wait for a fraction of a second */
166 temp = inb_p(SMBHSTSTS);
167 } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
169 /* If the SMBus is still busy, we give up */
170 if (timeout >= MAX_TIMEOUT) {
172 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
177 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
183 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
187 int read = inb_p(SMBHSTADD) & 0x01;
189 /* The quick and receive byte commands are used to probe
190 for chips, so errors are expected, and we don't want
191 to frighten the user. */
192 if (!((size == VT596_QUICK && !read) ||
193 (size == VT596_BYTE && read)))
194 dev_err(&vt596_adapter.dev, "Transaction error!\n");
197 /* Resetting status register */
199 outb_p(temp, SMBHSTSTS);
201 vt596_dump_regs("Transaction (post)", size);
206 /* Return negative errno on error, 0 on success */
207 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
208 unsigned short flags, char read_write, u8 command,
209 int size, union i2c_smbus_data *data)
215 case I2C_SMBUS_QUICK:
219 if (read_write == I2C_SMBUS_WRITE)
220 outb_p(command, SMBHSTCMD);
223 case I2C_SMBUS_BYTE_DATA:
224 outb_p(command, SMBHSTCMD);
225 if (read_write == I2C_SMBUS_WRITE)
226 outb_p(data->byte, SMBHSTDAT0);
227 size = VT596_BYTE_DATA;
229 case I2C_SMBUS_WORD_DATA:
230 outb_p(command, SMBHSTCMD);
231 if (read_write == I2C_SMBUS_WRITE) {
232 outb_p(data->word & 0xff, SMBHSTDAT0);
233 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
235 size = VT596_WORD_DATA;
237 case I2C_SMBUS_I2C_BLOCK_DATA:
238 if (!(vt596_features & FEATURE_I2CBLOCK))
239 goto exit_unsupported;
240 if (read_write == I2C_SMBUS_READ)
241 outb_p(data->block[0], SMBHSTDAT0);
243 case I2C_SMBUS_BLOCK_DATA:
244 outb_p(command, SMBHSTCMD);
245 if (read_write == I2C_SMBUS_WRITE) {
246 u8 len = data->block[0];
247 if (len > I2C_SMBUS_BLOCK_MAX)
248 len = I2C_SMBUS_BLOCK_MAX;
249 outb_p(len, SMBHSTDAT0);
250 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
251 for (i = 1; i <= len; i++)
252 outb_p(data->block[i], SMBBLKDAT);
254 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
255 VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
258 goto exit_unsupported;
261 outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
263 status = vt596_transaction(size);
267 if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
272 case VT596_BYTE_DATA:
273 data->byte = inb_p(SMBHSTDAT0);
275 case VT596_WORD_DATA:
276 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
278 case VT596_I2C_BLOCK_DATA:
279 case VT596_BLOCK_DATA:
280 data->block[0] = inb_p(SMBHSTDAT0);
281 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
282 data->block[0] = I2C_SMBUS_BLOCK_MAX;
283 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
284 for (i = 1; i <= data->block[0]; i++)
285 data->block[i] = inb_p(SMBBLKDAT);
291 dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
296 static u32 vt596_func(struct i2c_adapter *adapter)
298 u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
299 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
300 I2C_FUNC_SMBUS_BLOCK_DATA;
302 if (vt596_features & FEATURE_I2CBLOCK)
303 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
307 static const struct i2c_algorithm smbus_algorithm = {
308 .smbus_xfer = vt596_access,
309 .functionality = vt596_func,
312 static struct i2c_adapter vt596_adapter = {
313 .owner = THIS_MODULE,
314 .id = I2C_HW_SMBUS_VIA2,
315 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
316 .algo = &smbus_algorithm,
319 static int __devinit vt596_probe(struct pci_dev *pdev,
320 const struct pci_device_id *id)
325 /* driver_data might come from user-space, so check it */
326 if (id->driver_data & 1 || id->driver_data > 0xff)
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 "
397 dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
399 switch (pdev->device) {
400 case PCI_DEVICE_ID_VIA_CX700:
401 case PCI_DEVICE_ID_VIA_8251:
402 case PCI_DEVICE_ID_VIA_8237:
403 case PCI_DEVICE_ID_VIA_8237A:
404 case PCI_DEVICE_ID_VIA_8237S:
405 case PCI_DEVICE_ID_VIA_8235:
406 case PCI_DEVICE_ID_VIA_8233A:
407 case PCI_DEVICE_ID_VIA_8233_0:
408 vt596_features |= FEATURE_I2CBLOCK;
410 case PCI_DEVICE_ID_VIA_82C686_4:
411 /* The VT82C686B (rev 0x40) does support I2C block
412 transactions, but the VT82C686A (rev 0x30) doesn't */
413 if (pdev->revision >= 0x40)
414 vt596_features |= FEATURE_I2CBLOCK;
418 vt596_adapter.dev.parent = &pdev->dev;
419 snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
420 "SMBus Via Pro adapter at %04x", vt596_smba);
422 vt596_pdev = pci_dev_get(pdev);
423 if (i2c_add_adapter(&vt596_adapter)) {
424 pci_dev_put(vt596_pdev);
428 /* Always return failure here. This is to allow other drivers to bind
429 * to this pci device. We don't really want to have control over the
430 * pci device, we only wanted to read as few register values from it.
435 release_region(vt596_smba, 8);
439 static struct pci_device_id vt596_ids[] = {
440 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
441 .driver_data = SMBBA1 },
442 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
443 .driver_data = SMBBA1 },
444 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
445 .driver_data = SMBBA1 },
446 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
447 .driver_data = SMBBA3 },
448 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
449 .driver_data = SMBBA3 },
450 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
451 .driver_data = SMBBA3 },
452 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
453 .driver_data = SMBBA3 },
454 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
455 .driver_data = SMBBA3 },
456 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
457 .driver_data = SMBBA3 },
458 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
459 .driver_data = SMBBA1 },
460 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
461 .driver_data = SMBBA3 },
462 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
463 .driver_data = SMBBA3 },
467 MODULE_DEVICE_TABLE(pci, vt596_ids);
469 static struct pci_driver vt596_driver = {
470 .name = "vt596_smbus",
471 .id_table = vt596_ids,
472 .probe = vt596_probe,
473 .dynids.use_driver_data = 1,
476 static int __init i2c_vt596_init(void)
478 return pci_register_driver(&vt596_driver);
482 static void __exit i2c_vt596_exit(void)
484 pci_unregister_driver(&vt596_driver);
485 if (vt596_pdev != NULL) {
486 i2c_del_adapter(&vt596_adapter);
487 release_region(vt596_smba, 8);
488 pci_dev_put(vt596_pdev);
493 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
494 "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
495 "Jean Delvare <khali@linux-fr.org>");
496 MODULE_DESCRIPTION("vt82c596 SMBus driver");
497 MODULE_LICENSE("GPL");
499 module_init(i2c_vt596_init);
500 module_exit(i2c_vt596_exit);