treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / i2c / busses / i2c-viapro.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
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>
7
8 */
9
10 /*
11    Supports the following VIA south bridges:
12
13    Chip name          PCI ID  REV     I2C block
14    VT82C596A          0x3050             no
15    VT82C596B          0x3051             no
16    VT82C686A          0x3057  0x30       no
17    VT82C686B          0x3057  0x40       yes
18    VT8231             0x8235             no?
19    VT8233             0x3074             yes
20    VT8233A            0x3147             yes?
21    VT8235             0x3177             yes
22    VT8237R            0x3227             yes
23    VT8237A            0x3337             yes
24    VT8237S            0x3372             yes
25    VT8251             0x3287             yes
26    CX700              0x8324             yes
27    VX800/VX820        0x8353             yes
28    VX855/VX875        0x8409             yes
29
30    Note: we assume there can only be one device, with one SMBus interface.
31 */
32
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>
42 #include <linux/io.h>
43
44 static struct pci_dev *vt596_pdev;
45
46 #define SMBBA1          0x90
47 #define SMBBA2          0x80
48 #define SMBBA3          0xD0
49
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)
59
60 /* PCI Address Constants */
61
62 /* SMBus data in configuration space can be found in two places,
63    We try to select the better one */
64
65 static unsigned short SMBHSTCFG = 0xD2;
66
67 /* Other settings */
68 #define MAX_TIMEOUT     500
69
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
78
79
80 /* If force is set to anything different from 0, we forcibly enable the
81    VT596. DANGEROUS! */
82 static bool force;
83 module_param(force, bool, 0);
84 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
85
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!");
93
94
95 static struct pci_driver vt596_driver;
96 static struct i2c_adapter vt596_adapter;
97
98 #define FEATURE_I2CBLOCK        (1<<0)
99 static unsigned int vt596_features;
100
101 #ifdef DEBUG
102 static void vt596_dump_regs(const char *msg, u8 size)
103 {
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),
107                 inb_p(SMBHSTDAT1));
108
109         if (size == VT596_BLOCK_DATA
110          || size == VT596_I2C_BLOCK_DATA) {
111                 int i;
112
113                 dev_dbg(&vt596_adapter.dev, "BLK=");
114                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
115                         printk("%02x,", inb_p(SMBBLKDAT));
116                 printk("\n");
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));
121         }
122 }
123 #else
124 static inline void vt596_dump_regs(const char *msg, u8 size) { }
125 #endif
126
127 /* Return -1 on error, 0 on success */
128 static int vt596_transaction(u8 size)
129 {
130         int temp;
131         int result = 0;
132         int timeout = 0;
133
134         vt596_dump_regs("Transaction (pre)", size);
135
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);
140
141                 outb_p(temp, SMBHSTSTS);
142                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
143                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
144                                 "(0x%02x)\n", temp);
145                         return -EBUSY;
146                 }
147         }
148
149         /* Start the transaction by setting bit 6 */
150         outb_p(0x40 | size, SMBHSTCNT);
151
152         /* We will always wait for a fraction of a second */
153         do {
154                 msleep(1);
155                 temp = inb_p(SMBHSTSTS);
156         } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
157
158         /* If the SMBus is still busy, we give up */
159         if (timeout == MAX_TIMEOUT) {
160                 result = -ETIMEDOUT;
161                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
162         }
163
164         if (temp & 0x10) {
165                 result = -EIO;
166                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
167                         size);
168         }
169
170         if (temp & 0x08) {
171                 result = -EIO;
172                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
173         }
174
175         if (temp & 0x04) {
176                 result = -ENXIO;
177                 dev_dbg(&vt596_adapter.dev, "No response\n");
178         }
179
180         /* Resetting status register */
181         if (temp & 0x1F)
182                 outb_p(temp, SMBHSTSTS);
183
184         vt596_dump_regs("Transaction (post)", size);
185
186         return result;
187 }
188
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)
193 {
194         int i;
195         int status;
196
197         switch (size) {
198         case I2C_SMBUS_QUICK:
199                 size = VT596_QUICK;
200                 break;
201         case I2C_SMBUS_BYTE:
202                 if (read_write == I2C_SMBUS_WRITE)
203                         outb_p(command, SMBHSTCMD);
204                 size = VT596_BYTE;
205                 break;
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;
211                 break;
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);
217                 }
218                 size = VT596_WORD_DATA;
219                 break;
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;
225                 break;
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);
231                 /* Fall through */
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);
242                 }
243                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
244                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
245                 break;
246         default:
247                 goto exit_unsupported;
248         }
249
250         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
251
252         status = vt596_transaction(size);
253         if (status)
254                 return status;
255
256         if (size == VT596_PROC_CALL)
257                 read_write = I2C_SMBUS_READ;
258
259         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
260                 return 0;
261
262         switch (size) {
263         case VT596_BYTE:
264         case VT596_BYTE_DATA:
265                 data->byte = inb_p(SMBHSTDAT0);
266                 break;
267         case VT596_WORD_DATA:
268         case VT596_PROC_CALL:
269                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
270                 break;
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);
279                 break;
280         }
281         return 0;
282
283 exit_unsupported:
284         dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
285                  size);
286         return -EOPNOTSUPP;
287 }
288
289 static u32 vt596_func(struct i2c_adapter *adapter)
290 {
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;
294
295         if (vt596_features & FEATURE_I2CBLOCK)
296                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
297         return func;
298 }
299
300 static const struct i2c_algorithm smbus_algorithm = {
301         .smbus_xfer     = vt596_access,
302         .functionality  = vt596_func,
303 };
304
305 static struct i2c_adapter vt596_adapter = {
306         .owner          = THIS_MODULE,
307         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
308         .algo           = &smbus_algorithm,
309 };
310
311 static int vt596_probe(struct pci_dev *pdev,
312                        const struct pci_device_id *id)
313 {
314         unsigned char temp;
315         int error;
316
317         /* Determine the address of the SMBus areas */
318         if (force_addr) {
319                 vt596_smba = force_addr & 0xfff0;
320                 force = 0;
321                 goto found;
322         }
323
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)) {
330                         SMBHSTCFG = 0x84;
331                 } else {
332                         /* no matches at all */
333                         dev_err(&pdev->dev, "Cannot configure "
334                                 "SMBus I/O Base address\n");
335                         return -ENODEV;
336                 }
337         }
338
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");
344                 return -ENODEV;
345         }
346
347 found:
348         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
349         if (error)
350                 return -ENODEV;
351
352         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
353                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
354                         vt596_smba);
355                 return -ENODEV;
356         }
357
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. */
361         if (force_addr) {
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)) {
368                 if (force) {
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
373                          * this.
374                          */
375                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
376                         dev_info(&pdev->dev, "Enabling SMBus device\n");
377                 } else {
378                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
379                                 "controller not enabled! - upgrade BIOS or "
380                                 "use force=1\n");
381                         error = -ENODEV;
382                         goto release_region;
383                 }
384         }
385
386         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
387
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;
401                 break;
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;
407                 break;
408         }
409
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);
413
414         vt596_pdev = pci_dev_get(pdev);
415         error = i2c_add_adapter(&vt596_adapter);
416         if (error) {
417                 pci_dev_put(vt596_pdev);
418                 vt596_pdev = NULL;
419                 goto release_region;
420         }
421
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.
425          */
426         return -ENODEV;
427
428 release_region:
429         release_region(vt596_smba, 8);
430         return error;
431 }
432
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 },
464         { 0, }
465 };
466
467 MODULE_DEVICE_TABLE(pci, vt596_ids);
468
469 static struct pci_driver vt596_driver = {
470         .name           = "vt596_smbus",
471         .id_table       = vt596_ids,
472         .probe          = vt596_probe,
473 };
474
475 static int __init i2c_vt596_init(void)
476 {
477         return pci_register_driver(&vt596_driver);
478 }
479
480
481 static void __exit i2c_vt596_exit(void)
482 {
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);
488                 vt596_pdev = NULL;
489         }
490 }
491
492 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
493               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
494               "Jean Delvare <jdelvare@suse.de>");
495 MODULE_DESCRIPTION("vt82c596 SMBus driver");
496 MODULE_LICENSE("GPL");
497
498 module_init(i2c_vt596_init);
499 module_exit(i2c_vt596_exit);