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Linux/drivers/i2c/busses/i2c-viapro.c

  1 /*
  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 <jdelvare@suse.de>
  6 
  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.
 11 
 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.
 16 */
 17 
 18 /*
 19    Supports the following VIA south bridges:
 20 
 21    Chip name          PCI ID  REV     I2C block
 22    VT82C596A          0x3050             no
 23    VT82C596B          0x3051             no
 24    VT82C686A          0x3057  0x30       no
 25    VT82C686B          0x3057  0x40       yes
 26    VT8231             0x8235             no?
 27    VT8233             0x3074             yes
 28    VT8233A            0x3147             yes?
 29    VT8235             0x3177             yes
 30    VT8237R            0x3227             yes
 31    VT8237A            0x3337             yes
 32    VT8237S            0x3372             yes
 33    VT8251             0x3287             yes
 34    CX700              0x8324             yes
 35    VX800/VX820        0x8353             yes
 36    VX855/VX875        0x8409             yes
 37 
 38    Note: we assume there can only be one device, with one SMBus interface.
 39 */
 40 
 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>
 49 #include <linux/acpi.h>
 50 #include <linux/io.h>
 51 
 52 static struct pci_dev *vt596_pdev;
 53 
 54 #define SMBBA1          0x90
 55 #define SMBBA2          0x80
 56 #define SMBBA3          0xD0
 57 
 58 /* SMBus address offsets */
 59 static unsigned short vt596_smba;
 60 #define SMBHSTSTS       (vt596_smba + 0)
 61 #define SMBHSTCNT       (vt596_smba + 2)
 62 #define SMBHSTCMD       (vt596_smba + 3)
 63 #define SMBHSTADD       (vt596_smba + 4)
 64 #define SMBHSTDAT0      (vt596_smba + 5)
 65 #define SMBHSTDAT1      (vt596_smba + 6)
 66 #define SMBBLKDAT       (vt596_smba + 7)
 67 
 68 /* PCI Address Constants */
 69 
 70 /* SMBus data in configuration space can be found in two places,
 71    We try to select the better one */
 72 
 73 static unsigned short SMBHSTCFG = 0xD2;
 74 
 75 /* Other settings */
 76 #define MAX_TIMEOUT     500
 77 
 78 /* VT82C596 constants */
 79 #define VT596_QUICK             0x00
 80 #define VT596_BYTE              0x04
 81 #define VT596_BYTE_DATA         0x08
 82 #define VT596_WORD_DATA         0x0C
 83 #define VT596_PROC_CALL         0x10
 84 #define VT596_BLOCK_DATA        0x14
 85 #define VT596_I2C_BLOCK_DATA    0x34
 86 
 87 
 88 /* If force is set to anything different from 0, we forcibly enable the
 89    VT596. DANGEROUS! */
 90 static bool force;
 91 module_param(force, bool, 0);
 92 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
 93 
 94 /* If force_addr is set to anything different from 0, we forcibly enable
 95    the VT596 at the given address. VERY DANGEROUS! */
 96 static u16 force_addr;
 97 module_param(force_addr, ushort, 0);
 98 MODULE_PARM_DESC(force_addr,
 99                  "Forcibly enable the SMBus at the given address. "
100                  "EXTREMELY DANGEROUS!");
101 
102 
103 static struct pci_driver vt596_driver;
104 static struct i2c_adapter vt596_adapter;
105 
106 #define FEATURE_I2CBLOCK        (1<<0)
107 static unsigned int vt596_features;
108 
109 #ifdef DEBUG
110 static void vt596_dump_regs(const char *msg, u8 size)
111 {
112         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
113                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
114                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
115                 inb_p(SMBHSTDAT1));
116 
117         if (size == VT596_BLOCK_DATA
118          || size == VT596_I2C_BLOCK_DATA) {
119                 int i;
120 
121                 dev_dbg(&vt596_adapter.dev, "BLK=");
122                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
123                         printk("%02x,", inb_p(SMBBLKDAT));
124                 printk("\n");
125                 dev_dbg(&vt596_adapter.dev, "    ");
126                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
127                         printk("%02x,", inb_p(SMBBLKDAT));
128                 printk("%02x\n", inb_p(SMBBLKDAT));
129         }
130 }
131 #else
132 static inline void vt596_dump_regs(const char *msg, u8 size) { }
133 #endif
134 
135 /* Return -1 on error, 0 on success */
136 static int vt596_transaction(u8 size)
137 {
138         int temp;
139         int result = 0;
140         int timeout = 0;
141 
142         vt596_dump_regs("Transaction (pre)", size);
143 
144         /* Make sure the SMBus host is ready to start transmitting */
145         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
146                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
147                         "Resetting...\n", temp);
148 
149                 outb_p(temp, SMBHSTSTS);
150                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
151                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
152                                 "(0x%02x)\n", temp);
153                         return -EBUSY;
154                 }
155         }
156 
157         /* Start the transaction by setting bit 6 */
158         outb_p(0x40 | size, SMBHSTCNT);
159 
160         /* We will always wait for a fraction of a second */
161         do {
162                 msleep(1);
163                 temp = inb_p(SMBHSTSTS);
164         } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
165 
166         /* If the SMBus is still busy, we give up */
167         if (timeout == MAX_TIMEOUT) {
168                 result = -ETIMEDOUT;
169                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
170         }
171 
172         if (temp & 0x10) {
173                 result = -EIO;
174                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
175                         size);
176         }
177 
178         if (temp & 0x08) {
179                 result = -EIO;
180                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
181         }
182 
183         if (temp & 0x04) {
184                 result = -ENXIO;
185                 dev_dbg(&vt596_adapter.dev, "No response\n");
186         }
187 
188         /* Resetting status register */
189         if (temp & 0x1F)
190                 outb_p(temp, SMBHSTSTS);
191 
192         vt596_dump_regs("Transaction (post)", size);
193 
194         return result;
195 }
196 
197 /* Return negative errno on error, 0 on success */
198 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
199                 unsigned short flags, char read_write, u8 command,
200                 int size, union i2c_smbus_data *data)
201 {
202         int i;
203         int status;
204 
205         switch (size) {
206         case I2C_SMBUS_QUICK:
207                 size = VT596_QUICK;
208                 break;
209         case I2C_SMBUS_BYTE:
210                 if (read_write == I2C_SMBUS_WRITE)
211                         outb_p(command, SMBHSTCMD);
212                 size = VT596_BYTE;
213                 break;
214         case I2C_SMBUS_BYTE_DATA:
215                 outb_p(command, SMBHSTCMD);
216                 if (read_write == I2C_SMBUS_WRITE)
217                         outb_p(data->byte, SMBHSTDAT0);
218                 size = VT596_BYTE_DATA;
219                 break;
220         case I2C_SMBUS_WORD_DATA:
221                 outb_p(command, SMBHSTCMD);
222                 if (read_write == I2C_SMBUS_WRITE) {
223                         outb_p(data->word & 0xff, SMBHSTDAT0);
224                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
225                 }
226                 size = VT596_WORD_DATA;
227                 break;
228         case I2C_SMBUS_PROC_CALL:
229                 outb_p(command, SMBHSTCMD);
230                 outb_p(data->word & 0xff, SMBHSTDAT0);
231                 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
232                 size = VT596_PROC_CALL;
233                 break;
234         case I2C_SMBUS_I2C_BLOCK_DATA:
235                 if (!(vt596_features & FEATURE_I2CBLOCK))
236                         goto exit_unsupported;
237                 if (read_write == I2C_SMBUS_READ)
238                         outb_p(data->block[0], SMBHSTDAT0);
239                 /* Fall through */
240         case I2C_SMBUS_BLOCK_DATA:
241                 outb_p(command, SMBHSTCMD);
242                 if (read_write == I2C_SMBUS_WRITE) {
243                         u8 len = data->block[0];
244                         if (len > I2C_SMBUS_BLOCK_MAX)
245                                 len = I2C_SMBUS_BLOCK_MAX;
246                         outb_p(len, SMBHSTDAT0);
247                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
248                         for (i = 1; i <= len; i++)
249                                 outb_p(data->block[i], SMBBLKDAT);
250                 }
251                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
252                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
253                 break;
254         default:
255                 goto exit_unsupported;
256         }
257 
258         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
259 
260         status = vt596_transaction(size);
261         if (status)
262                 return status;
263 
264         if (size == VT596_PROC_CALL)
265                 read_write = I2C_SMBUS_READ;
266 
267         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
268                 return 0;
269 
270         switch (size) {
271         case VT596_BYTE:
272         case VT596_BYTE_DATA:
273                 data->byte = inb_p(SMBHSTDAT0);
274                 break;
275         case VT596_WORD_DATA:
276         case VT596_PROC_CALL:
277                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
278                 break;
279         case VT596_I2C_BLOCK_DATA:
280         case VT596_BLOCK_DATA:
281                 data->block[0] = inb_p(SMBHSTDAT0);
282                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
283                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
284                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
285                 for (i = 1; i <= data->block[0]; i++)
286                         data->block[i] = inb_p(SMBBLKDAT);
287                 break;
288         }
289         return 0;
290 
291 exit_unsupported:
292         dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
293                  size);
294         return -EOPNOTSUPP;
295 }
296 
297 static u32 vt596_func(struct i2c_adapter *adapter)
298 {
299         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
300             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
301             I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
302 
303         if (vt596_features & FEATURE_I2CBLOCK)
304                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
305         return func;
306 }
307 
308 static const struct i2c_algorithm smbus_algorithm = {
309         .smbus_xfer     = vt596_access,
310         .functionality  = vt596_func,
311 };
312 
313 static struct i2c_adapter vt596_adapter = {
314         .owner          = THIS_MODULE,
315         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
316         .algo           = &smbus_algorithm,
317 };
318 
319 static int vt596_probe(struct pci_dev *pdev,
320                        const struct pci_device_id *id)
321 {
322         unsigned char temp;
323         int error;
324 
325         /* Determine the address of the SMBus areas */
326         if (force_addr) {
327                 vt596_smba = force_addr & 0xfff0;
328                 force = 0;
329                 goto found;
330         }
331 
332         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
333             !(vt596_smba & 0x0001)) {
334                 /* try 2nd address and config reg. for 596 */
335                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
336                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
337                     (vt596_smba & 0x0001)) {
338                         SMBHSTCFG = 0x84;
339                 } else {
340                         /* no matches at all */
341                         dev_err(&pdev->dev, "Cannot configure "
342                                 "SMBus I/O Base address\n");
343                         return -ENODEV;
344                 }
345         }
346 
347         vt596_smba &= 0xfff0;
348         if (vt596_smba == 0) {
349                 dev_err(&pdev->dev, "SMBus base address "
350                         "uninitialized - upgrade BIOS or use "
351                         "force_addr=0xaddr\n");
352                 return -ENODEV;
353         }
354 
355 found:
356         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
357         if (error)
358                 return -ENODEV;
359 
360         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
361                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
362                         vt596_smba);
363                 return -ENODEV;
364         }
365 
366         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
367         /* If force_addr is set, we program the new address here. Just to make
368            sure, we disable the VT596 first. */
369         if (force_addr) {
370                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
371                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
372                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
373                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
374                          "address 0x%04x!\n", vt596_smba);
375         } else if (!(temp & 0x01)) {
376                 if (force) {
377                         /* NOTE: This assumes I/O space and other allocations
378                          * WERE done by the Bios!  Don't complain if your
379                          * hardware does weird things after enabling this.
380                          * :') Check for Bios updates before resorting to
381                          * this.
382                          */
383                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
384                         dev_info(&pdev->dev, "Enabling SMBus device\n");
385                 } else {
386                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
387                                 "controller not enabled! - upgrade BIOS or "
388                                 "use force=1\n");
389                         error = -ENODEV;
390                         goto release_region;
391                 }
392         }
393 
394         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
395 
396         switch (pdev->device) {
397         case PCI_DEVICE_ID_VIA_CX700:
398         case PCI_DEVICE_ID_VIA_VX800:
399         case PCI_DEVICE_ID_VIA_VX855:
400         case PCI_DEVICE_ID_VIA_VX900:
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;
409                 break;
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;
415                 break;
416         }
417 
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);
421 
422         vt596_pdev = pci_dev_get(pdev);
423         error = i2c_add_adapter(&vt596_adapter);
424         if (error) {
425                 pci_dev_put(vt596_pdev);
426                 vt596_pdev = NULL;
427                 goto release_region;
428         }
429 
430         /* Always return failure here.  This is to allow other drivers to bind
431          * to this pci device.  We don't really want to have control over the
432          * pci device, we only wanted to read as few register values from it.
433          */
434         return -ENODEV;
435 
436 release_region:
437         release_region(vt596_smba, 8);
438         return error;
439 }
440 
441 static const struct pci_device_id vt596_ids[] = {
442         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
443           .driver_data = SMBBA1 },
444         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
445           .driver_data = SMBBA1 },
446         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
447           .driver_data = SMBBA1 },
448         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
449           .driver_data = SMBBA3 },
450         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
451           .driver_data = SMBBA3 },
452         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
453           .driver_data = SMBBA3 },
454         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
455           .driver_data = SMBBA3 },
456         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
457           .driver_data = SMBBA3 },
458         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
459           .driver_data = SMBBA3 },
460         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
461           .driver_data = SMBBA1 },
462         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
463           .driver_data = SMBBA3 },
464         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
465           .driver_data = SMBBA3 },
466         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
467           .driver_data = SMBBA3 },
468         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855),
469           .driver_data = SMBBA3 },
470         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX900),
471           .driver_data = SMBBA3 },
472         { 0, }
473 };
474 
475 MODULE_DEVICE_TABLE(pci, vt596_ids);
476 
477 static struct pci_driver vt596_driver = {
478         .name           = "vt596_smbus",
479         .id_table       = vt596_ids,
480         .probe          = vt596_probe,
481 };
482 
483 static int __init i2c_vt596_init(void)
484 {
485         return pci_register_driver(&vt596_driver);
486 }
487 
488 
489 static void __exit i2c_vt596_exit(void)
490 {
491         pci_unregister_driver(&vt596_driver);
492         if (vt596_pdev != NULL) {
493                 i2c_del_adapter(&vt596_adapter);
494                 release_region(vt596_smba, 8);
495                 pci_dev_put(vt596_pdev);
496                 vt596_pdev = NULL;
497         }
498 }
499 
500 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
501               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
502               "Jean Delvare <jdelvare@suse.de>");
503 MODULE_DESCRIPTION("vt82c596 SMBus driver");
504 MODULE_LICENSE("GPL");
505 
506 module_init(i2c_vt596_init);
507 module_exit(i2c_vt596_exit);
508 

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