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Linux/drivers/i2c/busses/i2c-ali15x3.c

  1 /*
  2     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
  3     Philip Edelbrock <phil@netroedge.com> and
  4     Mark D. Studebaker <mdsxyz123@yahoo.com>
  5 
  6     This program is free software; you can redistribute it and/or modify
  7     it under the terms of the GNU General Public License as published by
  8     the Free Software Foundation; either version 2 of the License, or
  9     (at your option) any later version.
 10 
 11     This program is distributed in the hope that it will be useful,
 12     but WITHOUT ANY WARRANTY; without even the implied warranty of
 13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14     GNU General Public License for more details.
 15 */
 16 
 17 /*
 18     This is the driver for the SMB Host controller on
 19     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
 20 
 21     The M1543C is a South bridge for desktop systems.
 22     The M1533 is a South bridge for portable systems.
 23     They are part of the following ALI chipsets:
 24        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
 25        with AGP and 100MHz CPU Front Side bus
 26        "Aladdin V": Includes the M1541 Socket 7 North bridge
 27        with AGP and 100MHz CPU Front Side bus
 28        "Aladdin IV": Includes the M1541 Socket 7 North bridge
 29        with host bus up to 83.3 MHz.
 30     For an overview of these chips see http://www.acerlabs.com
 31 
 32     The M1533/M1543C devices appear as FOUR separate devices
 33     on the PCI bus. An output of lspci will show something similar
 34     to the following:
 35 
 36         00:02.0 USB Controller: Acer Laboratories Inc. M5237
 37         00:03.0 Bridge: Acer Laboratories Inc. M7101
 38         00:07.0 ISA bridge: Acer Laboratories Inc. M1533
 39         00:0f.0 IDE interface: Acer Laboratories Inc. M5229
 40 
 41     The SMB controller is part of the 7101 device, which is an
 42     ACPI-compliant Power Management Unit (PMU).
 43 
 44     The whole 7101 device has to be enabled for the SMB to work.
 45     You can't just enable the SMB alone.
 46     The SMB and the ACPI have separate I/O spaces.
 47     We make sure that the SMB is enabled. We leave the ACPI alone.
 48 
 49     This driver controls the SMB Host only.
 50     The SMB Slave controller on the M15X3 is not enabled.
 51 
 52     This driver does not use interrupts.
 53 */
 54 
 55 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
 56 
 57 #include <linux/module.h>
 58 #include <linux/pci.h>
 59 #include <linux/kernel.h>
 60 #include <linux/stddef.h>
 61 #include <linux/ioport.h>
 62 #include <linux/delay.h>
 63 #include <linux/i2c.h>
 64 #include <linux/acpi.h>
 65 #include <linux/io.h>
 66 
 67 /* ALI15X3 SMBus address offsets */
 68 #define SMBHSTSTS       (0 + ali15x3_smba)
 69 #define SMBHSTCNT       (1 + ali15x3_smba)
 70 #define SMBHSTSTART     (2 + ali15x3_smba)
 71 #define SMBHSTCMD       (7 + ali15x3_smba)
 72 #define SMBHSTADD       (3 + ali15x3_smba)
 73 #define SMBHSTDAT0      (4 + ali15x3_smba)
 74 #define SMBHSTDAT1      (5 + ali15x3_smba)
 75 #define SMBBLKDAT       (6 + ali15x3_smba)
 76 
 77 /* PCI Address Constants */
 78 #define SMBCOM          0x004
 79 #define SMBBA           0x014
 80 #define SMBATPC         0x05B   /* used to unlock xxxBA registers */
 81 #define SMBHSTCFG       0x0E0
 82 #define SMBSLVC         0x0E1
 83 #define SMBCLK          0x0E2
 84 #define SMBREV          0x008
 85 
 86 /* Other settings */
 87 #define MAX_TIMEOUT             200     /* times 1/100 sec */
 88 #define ALI15X3_SMB_IOSIZE      32
 89 
 90 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
 91    We don't use these here. If the bases aren't set to some value we
 92    tell user to upgrade BIOS and we fail.
 93 */
 94 #define ALI15X3_SMB_DEFAULTBASE 0xE800
 95 
 96 /* ALI15X3 address lock bits */
 97 #define ALI15X3_LOCK            0x06
 98 
 99 /* ALI15X3 command constants */
100 #define ALI15X3_ABORT           0x02
101 #define ALI15X3_T_OUT           0x04
102 #define ALI15X3_QUICK           0x00
103 #define ALI15X3_BYTE            0x10
104 #define ALI15X3_BYTE_DATA       0x20
105 #define ALI15X3_WORD_DATA       0x30
106 #define ALI15X3_BLOCK_DATA      0x40
107 #define ALI15X3_BLOCK_CLR       0x80
108 
109 /* ALI15X3 status register bits */
110 #define ALI15X3_STS_IDLE        0x04
111 #define ALI15X3_STS_BUSY        0x08
112 #define ALI15X3_STS_DONE        0x10
113 #define ALI15X3_STS_DEV         0x20    /* device error */
114 #define ALI15X3_STS_COLL        0x40    /* collision or no response */
115 #define ALI15X3_STS_TERM        0x80    /* terminated by abort */
116 #define ALI15X3_STS_ERR         0xE0    /* all the bad error bits */
117 
118 
119 /* If force_addr is set to anything different from 0, we forcibly enable
120    the device at the given address. */
121 static u16 force_addr;
122 module_param(force_addr, ushort, 0);
123 MODULE_PARM_DESC(force_addr,
124                  "Initialize the base address of the i2c controller");
125 
126 static struct pci_driver ali15x3_driver;
127 static unsigned short ali15x3_smba;
128 
129 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
130 {
131         u16 a;
132         unsigned char temp;
133 
134         /* Check the following things:
135                 - SMB I/O address is initialized
136                 - Device is enabled
137                 - We can use the addresses
138         */
139 
140         /* Unlock the register.
141            The data sheet says that the address registers are read-only
142            if the lock bits are 1, but in fact the address registers
143            are zero unless you clear the lock bits.
144         */
145         pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
146         if (temp & ALI15X3_LOCK) {
147                 temp &= ~ALI15X3_LOCK;
148                 pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
149         }
150 
151         /* Determine the address of the SMBus area */
152         pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
153         ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
154         if (ali15x3_smba == 0 && force_addr == 0) {
155                 dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
156                         "- upgrade BIOS or use force_addr=0xaddr\n");
157                 return -ENODEV;
158         }
159 
160         if(force_addr)
161                 ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
162 
163         if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
164                               ali15x3_driver.name))
165                 return -EBUSY;
166 
167         if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
168                             ali15x3_driver.name)) {
169                 dev_err(&ALI15X3_dev->dev,
170                         "ALI15X3_smb region 0x%x already in use!\n",
171                         ali15x3_smba);
172                 return -ENODEV;
173         }
174 
175         if(force_addr) {
176                 dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
177                         ali15x3_smba);
178                 if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
179                                                                 SMBBA,
180                                                                 ali15x3_smba))
181                         goto error;
182                 if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
183                                                                 SMBBA, &a))
184                         goto error;
185                 if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
186                         /* make sure it works */
187                         dev_err(&ALI15X3_dev->dev,
188                                 "force address failed - not supported?\n");
189                         goto error;
190                 }
191         }
192         /* check if whole device is enabled */
193         pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
194         if ((temp & 1) == 0) {
195                 dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
196                 pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
197         }
198 
199         /* Is SMB Host controller enabled? */
200         pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
201         if ((temp & 1) == 0) {
202                 dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
203                 pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
204         }
205 
206         /* set SMB clock to 74KHz as recommended in data sheet */
207         pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
208 
209         /*
210           The interrupt routing for SMB is set up in register 0x77 in the
211           1533 ISA Bridge device, NOT in the 7101 device.
212           Don't bother with finding the 1533 device and reading the register.
213         if ((....... & 0x0F) == 1)
214                 dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
215         */
216         pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
217         dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
218         dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
219 
220         return 0;
221 error:
222         release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
223         return -ENODEV;
224 }
225 
226 /* Another internally used function */
227 static int ali15x3_transaction(struct i2c_adapter *adap)
228 {
229         int temp;
230         int result = 0;
231         int timeout = 0;
232 
233         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
234                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
235                 inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
236                 inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
237 
238         /* get status */
239         temp = inb_p(SMBHSTSTS);
240 
241         /* Make sure the SMBus host is ready to start transmitting */
242         /* Check the busy bit first */
243         if (temp & ALI15X3_STS_BUSY) {
244         /*
245            If the host controller is still busy, it may have timed out in the
246            previous transaction, resulting in a "SMBus Timeout" Dev.
247            I've tried the following to reset a stuck busy bit.
248                 1. Reset the controller with an ABORT command.
249                    (this doesn't seem to clear the controller if an external
250                    device is hung)
251                 2. Reset the controller and the other SMBus devices with a
252                    T_OUT command.  (this clears the host busy bit if an
253                    external device is hung, but it comes back upon a new access
254                    to a device)
255                 3. Disable and reenable the controller in SMBHSTCFG
256            Worst case, nothing seems to work except power reset.
257         */
258         /* Abort - reset the host controller */
259         /*
260            Try resetting entire SMB bus, including other devices -
261            This may not work either - it clears the BUSY bit but
262            then the BUSY bit may come back on when you try and use the chip again.
263            If that's the case you are stuck.
264         */
265                 dev_info(&adap->dev, "Resetting entire SMB Bus to "
266                         "clear busy condition (%02x)\n", temp);
267                 outb_p(ALI15X3_T_OUT, SMBHSTCNT);
268                 temp = inb_p(SMBHSTSTS);
269         }
270 
271         /* now check the error bits and the busy bit */
272         if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
273                 /* do a clear-on-write */
274                 outb_p(0xFF, SMBHSTSTS);
275                 if ((temp = inb_p(SMBHSTSTS)) &
276                     (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
277                         /* this is probably going to be correctable only by a power reset
278                            as one of the bits now appears to be stuck */
279                         /* This may be a bus or device with electrical problems. */
280                         dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
281                                 "controller or device on bus is probably hung\n",
282                                 temp);
283                         return -EBUSY;
284                 }
285         } else {
286                 /* check and clear done bit */
287                 if (temp & ALI15X3_STS_DONE) {
288                         outb_p(temp, SMBHSTSTS);
289                 }
290         }
291 
292         /* start the transaction by writing anything to the start register */
293         outb_p(0xFF, SMBHSTSTART);
294 
295         /* We will always wait for a fraction of a second! */
296         timeout = 0;
297         do {
298                 msleep(1);
299                 temp = inb_p(SMBHSTSTS);
300         } while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
301                  && (timeout++ < MAX_TIMEOUT));
302 
303         /* If the SMBus is still busy, we give up */
304         if (timeout > MAX_TIMEOUT) {
305                 result = -ETIMEDOUT;
306                 dev_err(&adap->dev, "SMBus Timeout!\n");
307         }
308 
309         if (temp & ALI15X3_STS_TERM) {
310                 result = -EIO;
311                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
312         }
313 
314         /*
315           Unfortunately the ALI SMB controller maps "no response" and "bus
316           collision" into a single bit. No response is the usual case so don't
317           do a printk.
318           This means that bus collisions go unreported.
319         */
320         if (temp & ALI15X3_STS_COLL) {
321                 result = -ENXIO;
322                 dev_dbg(&adap->dev,
323                         "Error: no response or bus collision ADD=%02x\n",
324                         inb_p(SMBHSTADD));
325         }
326 
327         /* haven't ever seen this */
328         if (temp & ALI15X3_STS_DEV) {
329                 result = -EIO;
330                 dev_err(&adap->dev, "Error: device error\n");
331         }
332         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
333                 "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
334                 inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
335                 inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
336         return result;
337 }
338 
339 /* Return negative errno on error. */
340 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
341                    unsigned short flags, char read_write, u8 command,
342                    int size, union i2c_smbus_data * data)
343 {
344         int i, len;
345         int temp;
346         int timeout;
347 
348         /* clear all the bits (clear-on-write) */
349         outb_p(0xFF, SMBHSTSTS);
350         /* make sure SMBus is idle */
351         temp = inb_p(SMBHSTSTS);
352         for (timeout = 0;
353              (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
354              timeout++) {
355                 msleep(1);
356                 temp = inb_p(SMBHSTSTS);
357         }
358         if (timeout >= MAX_TIMEOUT) {
359                 dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
360         }
361 
362         switch (size) {
363         case I2C_SMBUS_QUICK:
364                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
365                        SMBHSTADD);
366                 size = ALI15X3_QUICK;
367                 break;
368         case I2C_SMBUS_BYTE:
369                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
370                        SMBHSTADD);
371                 if (read_write == I2C_SMBUS_WRITE)
372                         outb_p(command, SMBHSTCMD);
373                 size = ALI15X3_BYTE;
374                 break;
375         case I2C_SMBUS_BYTE_DATA:
376                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
377                        SMBHSTADD);
378                 outb_p(command, SMBHSTCMD);
379                 if (read_write == I2C_SMBUS_WRITE)
380                         outb_p(data->byte, SMBHSTDAT0);
381                 size = ALI15X3_BYTE_DATA;
382                 break;
383         case I2C_SMBUS_WORD_DATA:
384                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
385                        SMBHSTADD);
386                 outb_p(command, SMBHSTCMD);
387                 if (read_write == I2C_SMBUS_WRITE) {
388                         outb_p(data->word & 0xff, SMBHSTDAT0);
389                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
390                 }
391                 size = ALI15X3_WORD_DATA;
392                 break;
393         case I2C_SMBUS_BLOCK_DATA:
394                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
395                        SMBHSTADD);
396                 outb_p(command, SMBHSTCMD);
397                 if (read_write == I2C_SMBUS_WRITE) {
398                         len = data->block[0];
399                         if (len < 0) {
400                                 len = 0;
401                                 data->block[0] = len;
402                         }
403                         if (len > 32) {
404                                 len = 32;
405                                 data->block[0] = len;
406                         }
407                         outb_p(len, SMBHSTDAT0);
408                         /* Reset SMBBLKDAT */
409                         outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
410                         for (i = 1; i <= len; i++)
411                                 outb_p(data->block[i], SMBBLKDAT);
412                 }
413                 size = ALI15X3_BLOCK_DATA;
414                 break;
415         default:
416                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
417                 return -EOPNOTSUPP;
418         }
419 
420         outb_p(size, SMBHSTCNT);        /* output command */
421 
422         temp = ali15x3_transaction(adap);
423         if (temp)
424                 return temp;
425 
426         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
427                 return 0;
428 
429 
430         switch (size) {
431         case ALI15X3_BYTE:      /* Result put in SMBHSTDAT0 */
432                 data->byte = inb_p(SMBHSTDAT0);
433                 break;
434         case ALI15X3_BYTE_DATA:
435                 data->byte = inb_p(SMBHSTDAT0);
436                 break;
437         case ALI15X3_WORD_DATA:
438                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
439                 break;
440         case ALI15X3_BLOCK_DATA:
441                 len = inb_p(SMBHSTDAT0);
442                 if (len > 32)
443                         len = 32;
444                 data->block[0] = len;
445                 /* Reset SMBBLKDAT */
446                 outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
447                 for (i = 1; i <= data->block[0]; i++) {
448                         data->block[i] = inb_p(SMBBLKDAT);
449                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
450                                 len, i, data->block[i]);
451                 }
452                 break;
453         }
454         return 0;
455 }
456 
457 static u32 ali15x3_func(struct i2c_adapter *adapter)
458 {
459         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
460             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
461             I2C_FUNC_SMBUS_BLOCK_DATA;
462 }
463 
464 static const struct i2c_algorithm smbus_algorithm = {
465         .smbus_xfer     = ali15x3_access,
466         .functionality  = ali15x3_func,
467 };
468 
469 static struct i2c_adapter ali15x3_adapter = {
470         .owner          = THIS_MODULE,
471         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
472         .algo           = &smbus_algorithm,
473 };
474 
475 static const struct pci_device_id ali15x3_ids[] = {
476         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
477         { 0, }
478 };
479 
480 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
481 
482 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
483 {
484         if (ali15x3_setup(dev)) {
485                 dev_err(&dev->dev,
486                         "ALI15X3 not detected, module not inserted.\n");
487                 return -ENODEV;
488         }
489 
490         /* set up the sysfs linkage to our parent device */
491         ali15x3_adapter.dev.parent = &dev->dev;
492 
493         snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
494                 "SMBus ALI15X3 adapter at %04x", ali15x3_smba);
495         return i2c_add_adapter(&ali15x3_adapter);
496 }
497 
498 static void ali15x3_remove(struct pci_dev *dev)
499 {
500         i2c_del_adapter(&ali15x3_adapter);
501         release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
502 }
503 
504 static struct pci_driver ali15x3_driver = {
505         .name           = "ali15x3_smbus",
506         .id_table       = ali15x3_ids,
507         .probe          = ali15x3_probe,
508         .remove         = ali15x3_remove,
509 };
510 
511 module_pci_driver(ali15x3_driver);
512 
513 MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
514                 "Philip Edelbrock <phil@netroedge.com>, "
515                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
516 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
517 MODULE_LICENSE("GPL");
518 

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