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 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
38 Note: we assume there can only be one device, with one SMBus interface.
41 #include <linux/module.h>
42 #include <linux/delay.h>
43 #include <linux/pci.h>
44 #include <linux/kernel.h>
45 #include <linux/stddef.h>
46 #include <linux/ioport.h>
47 #include <linux/i2c.h>
48 #include <linux/init.h>
51 static struct pci_dev *vt596_pdev;
57 /* SMBus address offsets */
58 static unsigned short vt596_smba;
59 #define SMBHSTSTS (vt596_smba + 0)
60 #define SMBHSTCNT (vt596_smba + 2)
61 #define SMBHSTCMD (vt596_smba + 3)
62 #define SMBHSTADD (vt596_smba + 4)
63 #define SMBHSTDAT0 (vt596_smba + 5)
64 #define SMBHSTDAT1 (vt596_smba + 6)
65 #define SMBBLKDAT (vt596_smba + 7)
67 /* PCI Address Constants */
69 /* SMBus data in configuration space can be found in two places,
70 We try to select the better one */
72 static unsigned short SMBHSTCFG = 0xD2;
75 #define MAX_TIMEOUT 500
77 /* VT82C596 constants */
78 #define VT596_QUICK 0x00
79 #define VT596_BYTE 0x04
80 #define VT596_BYTE_DATA 0x08
81 #define VT596_WORD_DATA 0x0C
82 #define VT596_BLOCK_DATA 0x14
83 #define VT596_I2C_BLOCK_DATA 0x34
86 /* If force is set to anything different from 0, we forcibly enable the
89 module_param(force, bool, 0);
90 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
92 /* If force_addr is set to anything different from 0, we forcibly enable
93 the VT596 at the given address. VERY DANGEROUS! */
94 static u16 force_addr;
95 module_param(force_addr, ushort, 0);
96 MODULE_PARM_DESC(force_addr,
97 "Forcibly enable the SMBus at the given address. "
98 "EXTREMELY DANGEROUS!");
101 static struct pci_driver vt596_driver;
102 static struct i2c_adapter vt596_adapter;
104 #define FEATURE_I2CBLOCK (1<<0)
105 static unsigned int vt596_features;
108 static void vt596_dump_regs(const char *msg, u8 size)
110 dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
111 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
112 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
115 if (size == VT596_BLOCK_DATA
116 || size == VT596_I2C_BLOCK_DATA) {
119 dev_dbg(&vt596_adapter.dev, "BLK=");
120 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
121 printk("%02x,", inb_p(SMBBLKDAT));
123 dev_dbg(&vt596_adapter.dev, " ");
124 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
125 printk("%02x,", inb_p(SMBBLKDAT));
126 printk("%02x\n", inb_p(SMBBLKDAT));
130 static inline void vt596_dump_regs(const char *msg, u8 size) { }
133 /* Return -1 on error, 0 on success */
134 static int vt596_transaction(u8 size)
140 vt596_dump_regs("Transaction (pre)", size);
142 /* Make sure the SMBus host is ready to start transmitting */
143 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
144 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
145 "Resetting... ", temp);
147 outb_p(temp, SMBHSTSTS);
148 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
149 printk("Failed! (0x%02x)\n", temp);
152 printk("Successful!\n");
156 /* Start the transaction by setting bit 6 */
157 outb_p(0x40 | (size & 0x3C), SMBHSTCNT);
159 /* We will always wait for a fraction of a second */
162 temp = inb_p(SMBHSTSTS);
163 } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
165 /* If the SMBus is still busy, we give up */
166 if (timeout >= MAX_TIMEOUT) {
168 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
173 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
174 inb_p(SMBHSTCNT) & 0x3C);
179 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
184 /* Quick commands are used to probe for chips, so
185 errors are expected, and we don't want to frighten the
187 if ((inb_p(SMBHSTCNT) & 0x3C) != VT596_QUICK)
188 dev_err(&vt596_adapter.dev, "Transaction error!\n");
191 /* Resetting status register */
193 outb_p(temp, SMBHSTSTS);
195 vt596_dump_regs("Transaction (post)", size);
200 /* Return -1 on error, 0 on success */
201 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
202 unsigned short flags, char read_write, u8 command,
203 int size, union i2c_smbus_data *data)
208 case I2C_SMBUS_QUICK:
212 if (read_write == I2C_SMBUS_WRITE)
213 outb_p(command, SMBHSTCMD);
216 case I2C_SMBUS_BYTE_DATA:
217 outb_p(command, SMBHSTCMD);
218 if (read_write == I2C_SMBUS_WRITE)
219 outb_p(data->byte, SMBHSTDAT0);
220 size = VT596_BYTE_DATA;
222 case I2C_SMBUS_WORD_DATA:
223 outb_p(command, SMBHSTCMD);
224 if (read_write == I2C_SMBUS_WRITE) {
225 outb_p(data->word & 0xff, SMBHSTDAT0);
226 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
228 size = VT596_WORD_DATA;
230 case I2C_SMBUS_I2C_BLOCK_DATA:
231 if (!(vt596_features & FEATURE_I2CBLOCK))
232 goto exit_unsupported;
233 if (read_write == I2C_SMBUS_READ)
234 outb_p(I2C_SMBUS_BLOCK_MAX, SMBHSTDAT0);
236 case I2C_SMBUS_BLOCK_DATA:
237 outb_p(command, SMBHSTCMD);
238 if (read_write == I2C_SMBUS_WRITE) {
239 u8 len = data->block[0];
240 if (len > I2C_SMBUS_BLOCK_MAX)
241 len = I2C_SMBUS_BLOCK_MAX;
242 outb_p(len, SMBHSTDAT0);
243 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
244 for (i = 1; i <= len; i++)
245 outb_p(data->block[i], SMBBLKDAT);
247 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
248 VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
251 goto exit_unsupported;
254 outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
256 if (vt596_transaction(size)) /* Error in transaction */
259 if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
264 case VT596_BYTE_DATA:
265 data->byte = inb_p(SMBHSTDAT0);
267 case VT596_WORD_DATA:
268 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
270 case VT596_I2C_BLOCK_DATA:
271 case VT596_BLOCK_DATA:
272 data->block[0] = inb_p(SMBHSTDAT0);
273 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
274 data->block[0] = I2C_SMBUS_BLOCK_MAX;
275 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
276 for (i = 1; i <= data->block[0]; i++)
277 data->block[i] = inb_p(SMBBLKDAT);
283 dev_warn(&vt596_adapter.dev, "Unsupported command invoked! (0x%02x)\n",
288 static u32 vt596_func(struct i2c_adapter *adapter)
290 u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
291 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
292 I2C_FUNC_SMBUS_BLOCK_DATA;
294 if (vt596_features & FEATURE_I2CBLOCK)
295 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
299 static struct i2c_algorithm smbus_algorithm = {
300 .smbus_xfer = vt596_access,
301 .functionality = vt596_func,
304 static struct i2c_adapter vt596_adapter = {
305 .owner = THIS_MODULE,
306 .class = I2C_CLASS_HWMON,
307 .algo = &smbus_algorithm,
310 static int __devinit vt596_probe(struct pci_dev *pdev,
311 const struct pci_device_id *id)
316 /* Determine the address of the SMBus areas */
318 vt596_smba = force_addr & 0xfff0;
323 if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
324 !(vt596_smba & 0x0001)) {
325 /* try 2nd address and config reg. for 596 */
326 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
327 !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
328 (vt596_smba & 0x0001)) {
331 /* no matches at all */
332 dev_err(&pdev->dev, "Cannot configure "
333 "SMBus I/O Base address\n");
338 vt596_smba &= 0xfff0;
339 if (vt596_smba == 0) {
340 dev_err(&pdev->dev, "SMBus base address "
341 "uninitialized - upgrade BIOS or use "
342 "force_addr=0xaddr\n");
347 if (!request_region(vt596_smba, 8, vt596_driver.name)) {
348 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
353 pci_read_config_byte(pdev, SMBHSTCFG, &temp);
354 /* If force_addr is set, we program the new address here. Just to make
355 sure, we disable the VT596 first. */
357 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
358 pci_write_config_word(pdev, id->driver_data, vt596_smba);
359 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
360 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
361 "address 0x%04x!\n", vt596_smba);
362 } else if (!(temp & 0x01)) {
364 /* NOTE: This assumes I/O space and other allocations
365 * WERE done by the Bios! Don't complain if your
366 * hardware does weird things after enabling this.
367 * :') Check for Bios updates before resorting to
370 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
371 dev_info(&pdev->dev, "Enabling SMBus device\n");
373 dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
374 "controller not enabled! - upgrade BIOS or "
380 dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
382 switch (pdev->device) {
383 case PCI_DEVICE_ID_VIA_8237:
384 case PCI_DEVICE_ID_VIA_8235:
385 case PCI_DEVICE_ID_VIA_8233A:
386 case PCI_DEVICE_ID_VIA_8233_0:
387 vt596_features |= FEATURE_I2CBLOCK;
389 case PCI_DEVICE_ID_VIA_82C686_4:
390 /* The VT82C686B (rev 0x40) does support I2C block
391 transactions, but the VT82C686A (rev 0x30) doesn't */
392 if (!pci_read_config_byte(pdev, PCI_REVISION_ID, &temp)
394 vt596_features |= FEATURE_I2CBLOCK;
398 vt596_adapter.dev.parent = &pdev->dev;
399 snprintf(vt596_adapter.name, I2C_NAME_SIZE,
400 "SMBus Via Pro adapter at %04x", vt596_smba);
402 vt596_pdev = pci_dev_get(pdev);
403 if (i2c_add_adapter(&vt596_adapter)) {
404 pci_dev_put(vt596_pdev);
408 /* Always return failure here. This is to allow other drivers to bind
409 * to this pci device. We don't really want to have control over the
410 * pci device, we only wanted to read as few register values from it.
415 release_region(vt596_smba, 8);
419 static struct pci_device_id vt596_ids[] = {
420 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
421 .driver_data = SMBBA1 },
422 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
423 .driver_data = SMBBA1 },
424 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
425 .driver_data = SMBBA1 },
426 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
427 .driver_data = SMBBA3 },
428 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
429 .driver_data = SMBBA3 },
430 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
431 .driver_data = SMBBA3 },
432 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
433 .driver_data = SMBBA3 },
434 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
435 .driver_data = SMBBA1 },
439 MODULE_DEVICE_TABLE(pci, vt596_ids);
441 static struct pci_driver vt596_driver = {
442 .owner = THIS_MODULE,
443 .name = "vt596_smbus",
444 .id_table = vt596_ids,
445 .probe = vt596_probe,
448 static int __init i2c_vt596_init(void)
450 return pci_register_driver(&vt596_driver);
454 static void __exit i2c_vt596_exit(void)
456 pci_unregister_driver(&vt596_driver);
457 if (vt596_pdev != NULL) {
458 i2c_del_adapter(&vt596_adapter);
459 release_region(vt596_smba, 8);
460 pci_dev_put(vt596_pdev);
466 "Frodo Looijaard <frodol@dds.nl> and "
467 "Philip Edelbrock <phil@netroedge.com>");
468 MODULE_DESCRIPTION("vt82c596 SMBus driver");
469 MODULE_LICENSE("GPL");
471 module_init(i2c_vt596_init);
472 module_exit(i2c_vt596_exit);