1 // SPDX-License-Identifier: GPL-2.0-or-later
3 Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
4 Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
5 Mark D. Studebaker <mdsxyz123@yahoo.com>
6 Copyright (C) 2005 - 2008 Jean Delvare <jdelvare@suse.de>
11 Supports the following VIA south bridges:
13 Chip name PCI ID REV I2C block
16 VT82C686A 0x3057 0x30 no
17 VT82C686B 0x3057 0x40 yes
27 VX800/VX820 0x8353 yes
28 VX855/VX875 0x8409 yes
30 Note: we assume there can only be one device, with one SMBus interface.
33 #include <linux/module.h>
34 #include <linux/delay.h>
35 #include <linux/pci.h>
36 #include <linux/kernel.h>
37 #include <linux/stddef.h>
38 #include <linux/ioport.h>
39 #include <linux/i2c.h>
40 #include <linux/init.h>
41 #include <linux/acpi.h>
44 static struct pci_dev
*vt596_pdev
;
50 /* SMBus address offsets */
51 static unsigned short vt596_smba
;
52 #define SMBHSTSTS (vt596_smba + 0)
53 #define SMBHSTCNT (vt596_smba + 2)
54 #define SMBHSTCMD (vt596_smba + 3)
55 #define SMBHSTADD (vt596_smba + 4)
56 #define SMBHSTDAT0 (vt596_smba + 5)
57 #define SMBHSTDAT1 (vt596_smba + 6)
58 #define SMBBLKDAT (vt596_smba + 7)
60 /* PCI Address Constants */
62 /* SMBus data in configuration space can be found in two places,
63 We try to select the better one */
65 static unsigned short SMBHSTCFG
= 0xD2;
68 #define MAX_TIMEOUT 500
70 /* VT82C596 constants */
71 #define VT596_QUICK 0x00
72 #define VT596_BYTE 0x04
73 #define VT596_BYTE_DATA 0x08
74 #define VT596_WORD_DATA 0x0C
75 #define VT596_PROC_CALL 0x10
76 #define VT596_BLOCK_DATA 0x14
77 #define VT596_I2C_BLOCK_DATA 0x34
80 /* If force is set to anything different from 0, we forcibly enable the
83 module_param(force
, bool, 0);
84 MODULE_PARM_DESC(force
, "Forcibly enable the SMBus. DANGEROUS!");
86 /* If force_addr is set to anything different from 0, we forcibly enable
87 the VT596 at the given address. VERY DANGEROUS! */
88 static u16 force_addr
;
89 module_param_hw(force_addr
, ushort
, ioport
, 0);
90 MODULE_PARM_DESC(force_addr
,
91 "Forcibly enable the SMBus at the given address. "
92 "EXTREMELY DANGEROUS!");
95 static struct pci_driver vt596_driver
;
96 static struct i2c_adapter vt596_adapter
;
98 #define FEATURE_I2CBLOCK (1<<0)
99 static unsigned int vt596_features
;
102 static void vt596_dump_regs(const char *msg
, u8 size
)
104 dev_dbg(&vt596_adapter
.dev
, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
105 "DAT=%02x,%02x\n", msg
, inb_p(SMBHSTSTS
), inb_p(SMBHSTCNT
),
106 inb_p(SMBHSTCMD
), inb_p(SMBHSTADD
), inb_p(SMBHSTDAT0
),
109 if (size
== VT596_BLOCK_DATA
110 || size
== VT596_I2C_BLOCK_DATA
) {
113 dev_dbg(&vt596_adapter
.dev
, "BLK=");
114 for (i
= 0; i
< I2C_SMBUS_BLOCK_MAX
/ 2; i
++)
115 printk("%02x,", inb_p(SMBBLKDAT
));
117 dev_dbg(&vt596_adapter
.dev
, " ");
118 for (; i
< I2C_SMBUS_BLOCK_MAX
- 1; i
++)
119 printk("%02x,", inb_p(SMBBLKDAT
));
120 printk("%02x\n", inb_p(SMBBLKDAT
));
124 static inline void vt596_dump_regs(const char *msg
, u8 size
) { }
127 /* Return -1 on error, 0 on success */
128 static int vt596_transaction(u8 size
)
134 vt596_dump_regs("Transaction (pre)", size
);
136 /* Make sure the SMBus host is ready to start transmitting */
137 if ((temp
= inb_p(SMBHSTSTS
)) & 0x1F) {
138 dev_dbg(&vt596_adapter
.dev
, "SMBus busy (0x%02x). "
139 "Resetting...\n", temp
);
141 outb_p(temp
, SMBHSTSTS
);
142 if ((temp
= inb_p(SMBHSTSTS
)) & 0x1F) {
143 dev_err(&vt596_adapter
.dev
, "SMBus reset failed! "
149 /* Start the transaction by setting bit 6 */
150 outb_p(0x40 | size
, SMBHSTCNT
);
152 /* We will always wait for a fraction of a second */
155 temp
= inb_p(SMBHSTSTS
);
156 } while ((temp
& 0x01) && (++timeout
< MAX_TIMEOUT
));
158 /* If the SMBus is still busy, we give up */
159 if (timeout
== MAX_TIMEOUT
) {
161 dev_err(&vt596_adapter
.dev
, "SMBus timeout!\n");
166 dev_err(&vt596_adapter
.dev
, "Transaction failed (0x%02x)\n",
172 dev_err(&vt596_adapter
.dev
, "SMBus collision!\n");
177 dev_dbg(&vt596_adapter
.dev
, "No response\n");
180 /* Resetting status register */
182 outb_p(temp
, SMBHSTSTS
);
184 vt596_dump_regs("Transaction (post)", size
);
189 /* Return negative errno on error, 0 on success */
190 static s32
vt596_access(struct i2c_adapter
*adap
, u16 addr
,
191 unsigned short flags
, char read_write
, u8 command
,
192 int size
, union i2c_smbus_data
*data
)
198 case I2C_SMBUS_QUICK
:
202 if (read_write
== I2C_SMBUS_WRITE
)
203 outb_p(command
, SMBHSTCMD
);
206 case I2C_SMBUS_BYTE_DATA
:
207 outb_p(command
, SMBHSTCMD
);
208 if (read_write
== I2C_SMBUS_WRITE
)
209 outb_p(data
->byte
, SMBHSTDAT0
);
210 size
= VT596_BYTE_DATA
;
212 case I2C_SMBUS_WORD_DATA
:
213 outb_p(command
, SMBHSTCMD
);
214 if (read_write
== I2C_SMBUS_WRITE
) {
215 outb_p(data
->word
& 0xff, SMBHSTDAT0
);
216 outb_p((data
->word
& 0xff00) >> 8, SMBHSTDAT1
);
218 size
= VT596_WORD_DATA
;
220 case I2C_SMBUS_PROC_CALL
:
221 outb_p(command
, SMBHSTCMD
);
222 outb_p(data
->word
& 0xff, SMBHSTDAT0
);
223 outb_p((data
->word
& 0xff00) >> 8, SMBHSTDAT1
);
224 size
= VT596_PROC_CALL
;
226 case I2C_SMBUS_I2C_BLOCK_DATA
:
227 if (!(vt596_features
& FEATURE_I2CBLOCK
))
228 goto exit_unsupported
;
229 if (read_write
== I2C_SMBUS_READ
)
230 outb_p(data
->block
[0], SMBHSTDAT0
);
232 case I2C_SMBUS_BLOCK_DATA
:
233 outb_p(command
, SMBHSTCMD
);
234 if (read_write
== I2C_SMBUS_WRITE
) {
235 u8 len
= data
->block
[0];
236 if (len
> I2C_SMBUS_BLOCK_MAX
)
237 len
= I2C_SMBUS_BLOCK_MAX
;
238 outb_p(len
, SMBHSTDAT0
);
239 inb_p(SMBHSTCNT
); /* Reset SMBBLKDAT */
240 for (i
= 1; i
<= len
; i
++)
241 outb_p(data
->block
[i
], SMBBLKDAT
);
243 size
= (size
== I2C_SMBUS_I2C_BLOCK_DATA
) ?
244 VT596_I2C_BLOCK_DATA
: VT596_BLOCK_DATA
;
247 goto exit_unsupported
;
250 outb_p(((addr
& 0x7f) << 1) | read_write
, SMBHSTADD
);
252 status
= vt596_transaction(size
);
256 if (size
== VT596_PROC_CALL
)
257 read_write
= I2C_SMBUS_READ
;
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 case VT596_PROC_CALL
:
269 data
->word
= inb_p(SMBHSTDAT0
) + (inb_p(SMBHSTDAT1
) << 8);
271 case VT596_I2C_BLOCK_DATA
:
272 case VT596_BLOCK_DATA
:
273 data
->block
[0] = inb_p(SMBHSTDAT0
);
274 if (data
->block
[0] > I2C_SMBUS_BLOCK_MAX
)
275 data
->block
[0] = I2C_SMBUS_BLOCK_MAX
;
276 inb_p(SMBHSTCNT
); /* Reset SMBBLKDAT */
277 for (i
= 1; i
<= data
->block
[0]; i
++)
278 data
->block
[i
] = inb_p(SMBBLKDAT
);
284 dev_warn(&vt596_adapter
.dev
, "Unsupported transaction %d\n",
289 static u32
vt596_func(struct i2c_adapter
*adapter
)
291 u32 func
= I2C_FUNC_SMBUS_QUICK
| I2C_FUNC_SMBUS_BYTE
|
292 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
|
293 I2C_SMBUS_PROC_CALL
| I2C_FUNC_SMBUS_BLOCK_DATA
;
295 if (vt596_features
& FEATURE_I2CBLOCK
)
296 func
|= I2C_FUNC_SMBUS_I2C_BLOCK
;
300 static const struct i2c_algorithm smbus_algorithm
= {
301 .smbus_xfer
= vt596_access
,
302 .functionality
= vt596_func
,
305 static struct i2c_adapter vt596_adapter
= {
306 .owner
= THIS_MODULE
,
307 .class = I2C_CLASS_HWMON
,
308 .algo
= &smbus_algorithm
,
311 static int vt596_probe(struct pci_dev
*pdev
,
312 const struct pci_device_id
*id
)
317 /* Determine the address of the SMBus areas */
319 vt596_smba
= force_addr
& 0xfff0;
324 if ((pci_read_config_word(pdev
, id
->driver_data
, &vt596_smba
)) ||
325 !(vt596_smba
& 0x0001)) {
326 /* try 2nd address and config reg. for 596 */
327 if (id
->device
== PCI_DEVICE_ID_VIA_82C596_3
&&
328 !pci_read_config_word(pdev
, SMBBA2
, &vt596_smba
) &&
329 (vt596_smba
& 0x0001)) {
332 /* no matches at all */
333 dev_err(&pdev
->dev
, "Cannot configure "
334 "SMBus I/O Base address\n");
339 vt596_smba
&= 0xfff0;
340 if (vt596_smba
== 0) {
341 dev_err(&pdev
->dev
, "SMBus base address "
342 "uninitialized - upgrade BIOS or use "
343 "force_addr=0xaddr\n");
348 error
= acpi_check_region(vt596_smba
, 8, vt596_driver
.name
);
352 if (!request_region(vt596_smba
, 8, vt596_driver
.name
)) {
353 dev_err(&pdev
->dev
, "SMBus region 0x%x already in use!\n",
358 pci_read_config_byte(pdev
, SMBHSTCFG
, &temp
);
359 /* If force_addr is set, we program the new address here. Just to make
360 sure, we disable the VT596 first. */
362 pci_write_config_byte(pdev
, SMBHSTCFG
, temp
& 0xfe);
363 pci_write_config_word(pdev
, id
->driver_data
, vt596_smba
);
364 pci_write_config_byte(pdev
, SMBHSTCFG
, temp
| 0x01);
365 dev_warn(&pdev
->dev
, "WARNING: SMBus interface set to new "
366 "address 0x%04x!\n", vt596_smba
);
367 } else if (!(temp
& 0x01)) {
369 /* NOTE: This assumes I/O space and other allocations
370 * WERE done by the Bios! Don't complain if your
371 * hardware does weird things after enabling this.
372 * :') Check for Bios updates before resorting to
375 pci_write_config_byte(pdev
, SMBHSTCFG
, temp
| 0x01);
376 dev_info(&pdev
->dev
, "Enabling SMBus device\n");
378 dev_err(&pdev
->dev
, "SMBUS: Error: Host SMBus "
379 "controller not enabled! - upgrade BIOS or "
386 dev_dbg(&pdev
->dev
, "VT596_smba = 0x%X\n", vt596_smba
);
388 switch (pdev
->device
) {
389 case PCI_DEVICE_ID_VIA_CX700
:
390 case PCI_DEVICE_ID_VIA_VX800
:
391 case PCI_DEVICE_ID_VIA_VX855
:
392 case PCI_DEVICE_ID_VIA_VX900
:
393 case PCI_DEVICE_ID_VIA_8251
:
394 case PCI_DEVICE_ID_VIA_8237
:
395 case PCI_DEVICE_ID_VIA_8237A
:
396 case PCI_DEVICE_ID_VIA_8237S
:
397 case PCI_DEVICE_ID_VIA_8235
:
398 case PCI_DEVICE_ID_VIA_8233A
:
399 case PCI_DEVICE_ID_VIA_8233_0
:
400 vt596_features
|= FEATURE_I2CBLOCK
;
402 case PCI_DEVICE_ID_VIA_82C686_4
:
403 /* The VT82C686B (rev 0x40) does support I2C block
404 transactions, but the VT82C686A (rev 0x30) doesn't */
405 if (pdev
->revision
>= 0x40)
406 vt596_features
|= FEATURE_I2CBLOCK
;
410 vt596_adapter
.dev
.parent
= &pdev
->dev
;
411 snprintf(vt596_adapter
.name
, sizeof(vt596_adapter
.name
),
412 "SMBus Via Pro adapter at %04x", vt596_smba
);
414 vt596_pdev
= pci_dev_get(pdev
);
415 error
= i2c_add_adapter(&vt596_adapter
);
417 pci_dev_put(vt596_pdev
);
422 /* Always return failure here. This is to allow other drivers to bind
423 * to this pci device. We don't really want to have control over the
424 * pci device, we only wanted to read as few register values from it.
429 release_region(vt596_smba
, 8);
433 static const struct pci_device_id vt596_ids
[] = {
434 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_82C596_3
),
435 .driver_data
= SMBBA1
},
436 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_82C596B_3
),
437 .driver_data
= SMBBA1
},
438 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_82C686_4
),
439 .driver_data
= SMBBA1
},
440 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8233_0
),
441 .driver_data
= SMBBA3
},
442 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8233A
),
443 .driver_data
= SMBBA3
},
444 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8235
),
445 .driver_data
= SMBBA3
},
446 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8237
),
447 .driver_data
= SMBBA3
},
448 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8237A
),
449 .driver_data
= SMBBA3
},
450 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8237S
),
451 .driver_data
= SMBBA3
},
452 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8231_4
),
453 .driver_data
= SMBBA1
},
454 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_8251
),
455 .driver_data
= SMBBA3
},
456 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_CX700
),
457 .driver_data
= SMBBA3
},
458 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_VX800
),
459 .driver_data
= SMBBA3
},
460 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_VX855
),
461 .driver_data
= SMBBA3
},
462 { PCI_DEVICE(PCI_VENDOR_ID_VIA
, PCI_DEVICE_ID_VIA_VX900
),
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
,
475 static int __init
i2c_vt596_init(void)
477 return pci_register_driver(&vt596_driver
);
481 static void __exit
i2c_vt596_exit(void)
483 pci_unregister_driver(&vt596_driver
);
484 if (vt596_pdev
!= NULL
) {
485 i2c_del_adapter(&vt596_adapter
);
486 release_region(vt596_smba
, 8);
487 pci_dev_put(vt596_pdev
);
492 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>");
493 MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
494 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
495 MODULE_DESCRIPTION("vt82c596 SMBus driver");
496 MODULE_LICENSE("GPL");
498 module_init(i2c_vt596_init
);
499 module_exit(i2c_vt596_exit
);