Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2     i2c-viapro.c - Part of lm_sensors, Linux kernel modules for hardware
  3               monitoring
  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 
  8     This program is free software; you can redistribute it and/or modify
  9     it under the terms of the GNU General Public License as published by
 10     the Free Software Foundation; either version 2 of the License, or
 11     (at your option) any later version.
 12 
 13     This program is distributed in the hope that it will be useful,
 14     but WITHOUT ANY WARRANTY; without even the implied warranty of
 15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16     GNU General Public License for more details.
 17 
 18     You should have received a copy of the GNU General Public License
 19     along with this program; if not, write to the Free Software
 20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 21 */
 22 
 23 /*
 24    Supports Via devices:
 25         82C596A/B (0x3050)
 26         82C596B (0x3051)
 27         82C686A/B
 28         8231
 29         8233
 30         8233A (0x3147 and 0x3177)
 31         8235
 32         8237
 33    Note: we assume there can only be one device, with one SMBus interface.
 34 */
 35 
 36 #include <linux/config.h>
 37 #include <linux/module.h>
 38 #include <linux/delay.h>
 39 #include <linux/pci.h>
 40 #include <linux/kernel.h>
 41 #include <linux/stddef.h>
 42 #include <linux/sched.h>
 43 #include <linux/ioport.h>
 44 #include <linux/i2c.h>
 45 #include <linux/init.h>
 46 #include <asm/io.h>
 47 
 48 static struct pci_dev *vt596_pdev;
 49 
 50 #define SMBBA1           0x90
 51 #define SMBBA2           0x80
 52 #define SMBBA3           0xD0
 53 
 54 /* SMBus address offsets */
 55 static unsigned short vt596_smba;
 56 #define SMBHSTSTS       (vt596_smba + 0)
 57 #define SMBHSLVSTS      (vt596_smba + 1)
 58 #define SMBHSTCNT       (vt596_smba + 2)
 59 #define SMBHSTCMD       (vt596_smba + 3)
 60 #define SMBHSTADD       (vt596_smba + 4)
 61 #define SMBHSTDAT0      (vt596_smba + 5)
 62 #define SMBHSTDAT1      (vt596_smba + 6)
 63 #define SMBBLKDAT       (vt596_smba + 7)
 64 #define SMBSLVCNT       (vt596_smba + 8)
 65 #define SMBSHDWCMD      (vt596_smba + 9)
 66 #define SMBSLVEVT       (vt596_smba + 0xA)
 67 #define SMBSLVDAT       (vt596_smba + 0xC)
 68 
 69 /* PCI Address Constants */
 70 
 71 /* SMBus data in configuration space can be found in two places,
 72    We try to select the better one*/
 73 
 74 static unsigned short smb_cf_hstcfg = 0xD2;
 75 
 76 #define SMBHSTCFG   (smb_cf_hstcfg)
 77 #define SMBSLVC     (smb_cf_hstcfg + 1)
 78 #define SMBSHDW1    (smb_cf_hstcfg + 2)
 79 #define SMBSHDW2    (smb_cf_hstcfg + 3)
 80 #define SMBREV      (smb_cf_hstcfg + 4)
 81 
 82 /* Other settings */
 83 #define MAX_TIMEOUT     500
 84 #define ENABLE_INT9     0
 85 
 86 /* VT82C596 constants */
 87 #define VT596_QUICK      0x00
 88 #define VT596_BYTE       0x04
 89 #define VT596_BYTE_DATA  0x08
 90 #define VT596_WORD_DATA  0x0C
 91 #define VT596_BLOCK_DATA 0x14
 92 
 93 
 94 /* If force is set to anything different from 0, we forcibly enable the
 95    VT596. DANGEROUS! */
 96 static int force;
 97 module_param(force, bool, 0);
 98 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
 99 
100 /* If force_addr is set to anything different from 0, we forcibly enable
101    the VT596 at the given address. VERY DANGEROUS! */
102 static u16 force_addr;
103 module_param(force_addr, ushort, 0);
104 MODULE_PARM_DESC(force_addr,
105                  "Forcibly enable the SMBus at the given address. "
106                  "EXTREMELY DANGEROUS!");
107 
108 
109 static struct i2c_adapter vt596_adapter;
110 
111 /* Another internally used function */
112 static int vt596_transaction(void)
113 {
114         int temp;
115         int result = 0;
116         int timeout = 0;
117 
118         dev_dbg(&vt596_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
119                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT), 
120                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), 
121                 inb_p(SMBHSTDAT1));
122 
123         /* Make sure the SMBus host is ready to start transmitting */
124         if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
125                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
126                                 "Resetting...\n", temp);
127                 
128                 outb_p(temp, SMBHSTSTS);
129                 if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
130                         dev_dbg(&vt596_adapter.dev, "Failed! (0x%02x)\n", temp);
131                         
132                         return -1;
133                 } else {
134                         dev_dbg(&vt596_adapter.dev, "Successfull!\n");
135                 }
136         }
137 
138         /* start the transaction by setting bit 6 */
139         outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
140 
141         /* We will always wait for a fraction of a second! 
142            I don't know if VIA needs this, Intel did  */
143         do {
144                 msleep(1);
145                 temp = inb_p(SMBHSTSTS);
146         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
147 
148         /* If the SMBus is still busy, we give up */
149         if (timeout >= MAX_TIMEOUT) {
150                 result = -1;
151                 dev_dbg(&vt596_adapter.dev, "SMBus Timeout!\n");
152         }
153 
154         if (temp & 0x10) {
155                 result = -1;
156                 dev_dbg(&vt596_adapter.dev, "Error: Failed bus transaction\n");
157         }
158 
159         if (temp & 0x08) {
160                 result = -1;
161                 dev_info(&vt596_adapter.dev, "Bus collision! SMBus may be "
162                         "locked until next hard\nreset. (sorry!)\n");
163                 /* Clock stops and slave is stuck in mid-transmission */
164         }
165 
166         if (temp & 0x04) {
167                 result = -1;
168                 dev_dbg(&vt596_adapter.dev, "Error: no response!\n");
169         }
170 
171         if (inb_p(SMBHSTSTS) != 0x00)
172                 outb_p(inb(SMBHSTSTS), SMBHSTSTS);
173 
174         if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
175                 dev_dbg(&vt596_adapter.dev, "Failed reset at end of "
176                         "transaction (%02x)\n", temp);
177         }
178         dev_dbg(&vt596_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
179                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
180                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), 
181                 inb_p(SMBHSTDAT1));
182         
183         return result;
184 }
185 
186 /* Return -1 on error. */
187 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
188                 unsigned short flags,  char read_write, u8 command,
189                 int size,  union i2c_smbus_data *data)
190 {
191         int i, len;
192 
193         switch (size) {
194         case I2C_SMBUS_PROC_CALL:
195                 dev_info(&vt596_adapter.dev,
196                          "I2C_SMBUS_PROC_CALL not supported!\n");
197                 return -1;
198         case I2C_SMBUS_QUICK:
199                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
200                        SMBHSTADD);
201                 size = VT596_QUICK;
202                 break;
203         case I2C_SMBUS_BYTE:
204                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
205                        SMBHSTADD);
206                 if (read_write == I2C_SMBUS_WRITE)
207                         outb_p(command, SMBHSTCMD);
208                 size = VT596_BYTE;
209                 break;
210         case I2C_SMBUS_BYTE_DATA:
211                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
212                        SMBHSTADD);
213                 outb_p(command, SMBHSTCMD);
214                 if (read_write == I2C_SMBUS_WRITE)
215                         outb_p(data->byte, SMBHSTDAT0);
216                 size = VT596_BYTE_DATA;
217                 break;
218         case I2C_SMBUS_WORD_DATA:
219                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
220                        SMBHSTADD);
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_BLOCK_DATA:
229                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
230                        SMBHSTADD);
231                 outb_p(command, SMBHSTCMD);
232                 if (read_write == I2C_SMBUS_WRITE) {
233                         len = data->block[0];
234                         if (len < 0)
235                                 len = 0;
236                         if (len > I2C_SMBUS_BLOCK_MAX)
237                                 len = I2C_SMBUS_BLOCK_MAX;
238                         outb_p(len, SMBHSTDAT0);
239                         i = inb_p(SMBHSTCNT);   /* Reset SMBBLKDAT */
240                         for (i = 1; i <= len; i++)
241                                 outb_p(data->block[i], SMBBLKDAT);
242                 }
243                 size = VT596_BLOCK_DATA;
244                 break;
245         }
246 
247         outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
248 
249         if (vt596_transaction()) /* Error in transaction */
250                 return -1;
251 
252         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
253                 return 0;
254 
255         switch (size) {
256         case VT596_BYTE:
257                 /* Where is the result put? I assume here it is in
258                  * SMBHSTDAT0 but it might just as well be in the
259                  * SMBHSTCMD. No clue in the docs 
260                  */
261                 data->byte = inb_p(SMBHSTDAT0);
262                 break;
263         case VT596_BYTE_DATA:
264                 data->byte = inb_p(SMBHSTDAT0);
265                 break;
266         case VT596_WORD_DATA:
267                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
268                 break;
269         case VT596_BLOCK_DATA:
270                 data->block[0] = inb_p(SMBHSTDAT0);
271                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
272                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
273                 i = inb_p(SMBHSTCNT);   /* Reset SMBBLKDAT */
274                 for (i = 1; i <= data->block[0]; i++)
275                         data->block[i] = inb_p(SMBBLKDAT);
276                 break;
277         }
278         return 0;
279 }
280 
281 static u32 vt596_func(struct i2c_adapter *adapter)
282 {
283         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
284             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
285             I2C_FUNC_SMBUS_BLOCK_DATA;
286 }
287 
288 static struct i2c_algorithm smbus_algorithm = {
289         .name           = "Non-I2C SMBus adapter",
290         .id             = I2C_ALGO_SMBUS,
291         .smbus_xfer     = vt596_access,
292         .functionality  = vt596_func,
293 };
294 
295 static struct i2c_adapter vt596_adapter = {
296         .owner          = THIS_MODULE,
297         .class          = I2C_CLASS_HWMON,
298         .algo           = &smbus_algorithm,
299         .name           = "unset",
300 };
301 
302 static int __devinit vt596_probe(struct pci_dev *pdev,
303                                  const struct pci_device_id *id)
304 {
305         unsigned char temp;
306         int error = -ENODEV;
307         
308         /* Determine the address of the SMBus areas */
309         if (force_addr) {
310                 vt596_smba = force_addr & 0xfff0;
311                 force = 0;
312                 goto found;
313         }
314 
315         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
316             !(vt596_smba & 0x1)) {
317                 /* try 2nd address and config reg. for 596 */
318                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
319                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
320                     (vt596_smba & 0x1)) {
321                         smb_cf_hstcfg = 0x84;
322                 } else {
323                         /* no matches at all */
324                         dev_err(&pdev->dev, "Cannot configure "
325                                 "SMBus I/O Base address\n");
326                         return -ENODEV;
327                 }
328         }
329 
330         vt596_smba &= 0xfff0;
331         if (vt596_smba == 0) {
332                 dev_err(&pdev->dev, "SMBus base address "
333                         "uninitialized - upgrade BIOS or use "
334                         "force_addr=0xaddr\n");
335                 return -ENODEV;
336         }
337 
338  found:
339         if (!request_region(vt596_smba, 8, "viapro-smbus")) {
340                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
341                         vt596_smba);
342                 return -ENODEV;
343         }
344 
345         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
346         /* If force_addr is set, we program the new address here. Just to make
347            sure, we disable the VT596 first. */
348         if (force_addr) {
349                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
350                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
351                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
352                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
353                      "address 0x%04x!\n", vt596_smba);
354         } else if ((temp & 1) == 0) {
355                 if (force) {
356                         /* NOTE: This assumes I/O space and other allocations 
357                          * WERE done by the Bios!  Don't complain if your 
358                          * hardware does weird things after enabling this. 
359                          * :') Check for Bios updates before resorting to 
360                          * this.
361                          */
362                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 1);
363                         dev_info(&pdev->dev, "Enabling SMBus device\n");
364                 } else {
365                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
366                                 "controller not enabled! - upgrade BIOS or "
367                                 "use force=1\n");
368                         goto release_region;
369                 }
370         }
371 
372         if ((temp & 0x0E) == 8)
373                 dev_dbg(&pdev->dev, "using Interrupt 9 for SMBus.\n");
374         else if ((temp & 0x0E) == 0)
375                 dev_dbg(&pdev->dev, "using Interrupt SMI# for SMBus.\n");
376         else
377                 dev_dbg(&pdev->dev, "Illegal Interrupt configuration "
378                         "(or code out of date)!\n");
379 
380         pci_read_config_byte(pdev, SMBREV, &temp);
381         dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
382         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
383 
384         vt596_adapter.dev.parent = &pdev->dev;
385         snprintf(vt596_adapter.name, I2C_NAME_SIZE,
386                         "SMBus Via Pro adapter at %04x", vt596_smba);
387         
388         vt596_pdev = pci_dev_get(pdev);
389         if (i2c_add_adapter(&vt596_adapter)) {
390                 pci_dev_put(vt596_pdev);
391                 vt596_pdev = NULL;
392         }
393 
394         /* Always return failure here.  This is to allow other drivers to bind
395          * to this pci device.  We don't really want to have control over the
396          * pci device, we only wanted to read as few register values from it.
397          */
398         return -ENODEV;
399 
400  release_region:
401         release_region(vt596_smba, 8);
402         return error;
403 }
404 
405 static struct pci_device_id vt596_ids[] = {
406         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
407           .driver_data = SMBBA1 },
408         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
409           .driver_data = SMBBA1 },
410         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
411           .driver_data = SMBBA1 },
412         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
413           .driver_data = SMBBA3 },
414         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
415           .driver_data = SMBBA3 },
416         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
417           .driver_data = SMBBA3 },
418         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
419           .driver_data = SMBBA3 },
420         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
421           .driver_data = SMBBA1 },
422         { 0, }
423 };
424 
425 MODULE_DEVICE_TABLE (pci, vt596_ids);
426 
427 static struct pci_driver vt596_driver = {
428         .name           = "vt596_smbus",
429         .id_table       = vt596_ids,
430         .probe          = vt596_probe,
431 };
432 
433 static int __init i2c_vt596_init(void)
434 {
435         return pci_register_driver(&vt596_driver);
436 }
437 
438 
439 static void __exit i2c_vt596_exit(void)
440 {
441         pci_unregister_driver(&vt596_driver);
442         if (vt596_pdev != NULL) {
443                 i2c_del_adapter(&vt596_adapter);
444                 release_region(vt596_smba, 8);
445                 pci_dev_put(vt596_pdev);
446                 vt596_pdev = NULL;
447         }
448 }
449 
450 MODULE_AUTHOR(
451     "Frodo Looijaard <frodol@dds.nl> and "
452     "Philip Edelbrock <phil@netroedge.com>");
453 MODULE_DESCRIPTION("vt82c596 SMBus driver");
454 MODULE_LICENSE("GPL");
455 
456 module_init(i2c_vt596_init);
457 module_exit(i2c_vt596_exit);
458 
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