[PATCH] i2c: scx200_acb add support for the CS5535/CS5536
[linux-3.10.git] / drivers / i2c / busses / scx200_acb.c
1 /*
2     Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
3
4     National Semiconductor SCx200 ACCESS.bus support
5     Also supports the AMD CS5535 and AMD CS5536
6
7     Based on i2c-keywest.c which is:
8         Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
9         Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
10
11     This program is free software; you can redistribute it and/or
12     modify it under the terms of the GNU General Public License as
13     published by the Free Software Foundation; either version 2 of the
14     License, or (at your option) any later version.
15
16     This program is distributed in the hope that it will be useful,
17     but WITHOUT ANY WARRANTY; without even the implied warranty of
18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19     General Public License for more details.
20
21     You should have received a copy of the GNU General Public License
22     along with this program; if not, write to the Free Software
23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/i2c.h>
31 #include <linux/smp_lock.h>
32 #include <linux/pci.h>
33 #include <linux/delay.h>
34 #include <asm/io.h>
35 #include <asm/msr.h>
36
37 #include <linux/scx200.h>
38
39 #define NAME "scx200_acb"
40
41 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
42 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
43 MODULE_LICENSE("GPL");
44
45 #define MAX_DEVICES 4
46 static int base[MAX_DEVICES] = { 0x820, 0x840 };
47 module_param_array(base, int, NULL, 0);
48 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
49
50 /* The hardware supports interrupt driven mode too, but I haven't
51    implemented that. */
52 #define POLLED_MODE 1
53 #define POLL_TIMEOUT (HZ)
54
55 enum scx200_acb_state {
56         state_idle,
57         state_address,
58         state_command,
59         state_repeat_start,
60         state_quick,
61         state_read,
62         state_write,
63 };
64
65 static const char *scx200_acb_state_name[] = {
66         "idle",
67         "address",
68         "command",
69         "repeat_start",
70         "quick",
71         "read",
72         "write",
73 };
74
75 /* Physical interface */
76 struct scx200_acb_iface {
77         struct scx200_acb_iface *next;
78         struct i2c_adapter adapter;
79         unsigned base;
80         struct semaphore sem;
81
82         /* State machine data */
83         enum scx200_acb_state state;
84         int result;
85         u8 address_byte;
86         u8 command;
87         u8 *ptr;
88         char needs_reset;
89         unsigned len;
90 };
91
92 /* Register Definitions */
93 #define ACBSDA          (iface->base + 0)
94 #define ACBST           (iface->base + 1)
95 #define    ACBST_SDAST          0x40 /* SDA Status */
96 #define    ACBST_BER            0x20
97 #define    ACBST_NEGACK         0x10 /* Negative Acknowledge */
98 #define    ACBST_STASTR         0x08 /* Stall After Start */
99 #define    ACBST_MASTER         0x02
100 #define ACBCST          (iface->base + 2)
101 #define    ACBCST_BB            0x02
102 #define ACBCTL1         (iface->base + 3)
103 #define    ACBCTL1_STASTRE      0x80
104 #define    ACBCTL1_NMINTE       0x40
105 #define    ACBCTL1_ACK          0x10
106 #define    ACBCTL1_STOP         0x02
107 #define    ACBCTL1_START        0x01
108 #define ACBADDR         (iface->base + 4)
109 #define ACBCTL2         (iface->base + 5)
110 #define    ACBCTL2_ENABLE       0x01
111
112 /************************************************************************/
113
114 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
115 {
116         const char *errmsg;
117
118         dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
119                 scx200_acb_state_name[iface->state], status);
120
121         if (status & ACBST_BER) {
122                 errmsg = "bus error";
123                 goto error;
124         }
125         if (!(status & ACBST_MASTER)) {
126                 errmsg = "not master";
127                 goto error;
128         }
129         if (status & ACBST_NEGACK) {
130                 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
131                         scx200_acb_state_name[iface->state]);
132
133                 iface->state = state_idle;
134                 iface->result = -ENXIO;
135
136                 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
137                 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
138                 return;
139         }
140
141         switch (iface->state) {
142         case state_idle:
143                 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
144                 break;
145
146         case state_address:
147                 /* Do a pointer write first */
148                 outb(iface->address_byte & ~1, ACBSDA);
149
150                 iface->state = state_command;
151                 break;
152
153         case state_command:
154                 outb(iface->command, ACBSDA);
155
156                 if (iface->address_byte & 1)
157                         iface->state = state_repeat_start;
158                 else
159                         iface->state = state_write;
160                 break;
161
162         case state_repeat_start:
163                 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
164                 /* fallthrough */
165
166         case state_quick:
167                 if (iface->address_byte & 1) {
168                         if (iface->len == 1)
169                                 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
170                         else
171                                 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
172                         outb(iface->address_byte, ACBSDA);
173
174                         iface->state = state_read;
175                 } else {
176                         outb(iface->address_byte, ACBSDA);
177
178                         iface->state = state_write;
179                 }
180                 break;
181
182         case state_read:
183                 /* Set ACK if receiving the last byte */
184                 if (iface->len == 1)
185                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
186                 else
187                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
188
189                 *iface->ptr++ = inb(ACBSDA);
190                 --iface->len;
191
192                 if (iface->len == 0) {
193                         iface->result = 0;
194                         iface->state = state_idle;
195                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
196                 }
197
198                 break;
199
200         case state_write:
201                 if (iface->len == 0) {
202                         iface->result = 0;
203                         iface->state = state_idle;
204                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
205                         break;
206                 }
207
208                 outb(*iface->ptr++, ACBSDA);
209                 --iface->len;
210
211                 break;
212         }
213
214         return;
215
216  error:
217         dev_err(&iface->adapter.dev, "%s in state %s\n", errmsg,
218                 scx200_acb_state_name[iface->state]);
219
220         iface->state = state_idle;
221         iface->result = -EIO;
222         iface->needs_reset = 1;
223 }
224
225 #ifdef POLLED_MODE
226 static void scx200_acb_poll(struct scx200_acb_iface *iface)
227 {
228         u8 status;
229         unsigned long timeout;
230
231         timeout = jiffies + POLL_TIMEOUT;
232         while (time_before(jiffies, timeout)) {
233                 status = inb(ACBST);
234                 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
235                         scx200_acb_machine(iface, status);
236                         return;
237                 }
238                 msleep(10);
239         }
240
241         dev_err(&iface->adapter.dev, "timeout in state %s\n",
242                 scx200_acb_state_name[iface->state]);
243
244         iface->state = state_idle;
245         iface->result = -EIO;
246         iface->needs_reset = 1;
247 }
248 #endif /* POLLED_MODE */
249
250 static void scx200_acb_reset(struct scx200_acb_iface *iface)
251 {
252         /* Disable the ACCESS.bus device and Configure the SCL
253            frequency: 16 clock cycles */
254         outb(0x70, ACBCTL2);
255         /* Polling mode */
256         outb(0, ACBCTL1);
257         /* Disable slave address */
258         outb(0, ACBADDR);
259         /* Enable the ACCESS.bus device */
260         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
261         /* Free STALL after START */
262         outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
263         /* Send a STOP */
264         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
265         /* Clear BER, NEGACK and STASTR bits */
266         outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
267         /* Clear BB bit */
268         outb(inb(ACBCST) | ACBCST_BB, ACBCST);
269 }
270
271 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
272                                  u16 address, unsigned short flags,
273                                  char rw, u8 command, int size,
274                                  union i2c_smbus_data *data)
275 {
276         struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
277         int len;
278         u8 *buffer;
279         u16 cur_word;
280         int rc;
281
282         switch (size) {
283         case I2C_SMBUS_QUICK:
284                 len = 0;
285                 buffer = NULL;
286                 break;
287
288         case I2C_SMBUS_BYTE:
289                 len = 1;
290                 buffer = rw ? &data->byte : &command;
291                 break;
292
293         case I2C_SMBUS_BYTE_DATA:
294                 len = 1;
295                 buffer = &data->byte;
296                 break;
297
298         case I2C_SMBUS_WORD_DATA:
299                 len = 2;
300                 cur_word = cpu_to_le16(data->word);
301                 buffer = (u8 *)&cur_word;
302                 break;
303
304         case I2C_SMBUS_BLOCK_DATA:
305                 len = data->block[0];
306                 buffer = &data->block[1];
307                 break;
308
309         default:
310                 return -EINVAL;
311         }
312
313         dev_dbg(&adapter->dev,
314                 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
315                 size, address, command, len, rw);
316
317         if (!len && rw == I2C_SMBUS_READ) {
318                 dev_dbg(&adapter->dev, "zero length read\n");
319                 return -EINVAL;
320         }
321
322         down(&iface->sem);
323
324         iface->address_byte = (address << 1) | rw;
325         iface->command = command;
326         iface->ptr = buffer;
327         iface->len = len;
328         iface->result = -EINVAL;
329         iface->needs_reset = 0;
330
331         outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
332
333         if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
334                 iface->state = state_quick;
335         else
336                 iface->state = state_address;
337
338 #ifdef POLLED_MODE
339         while (iface->state != state_idle)
340                 scx200_acb_poll(iface);
341 #else /* POLLED_MODE */
342 #error Interrupt driven mode not implemented
343 #endif /* POLLED_MODE */        
344
345         if (iface->needs_reset)
346                 scx200_acb_reset(iface);
347
348         rc = iface->result;
349
350         up(&iface->sem);
351
352         if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
353                 data->word = le16_to_cpu(cur_word);
354
355 #ifdef DEBUG
356         dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
357         if (buffer) {
358                 int i;
359                 printk(" data:");
360                 for (i = 0; i < len; ++i)
361                         printk(" %02x", buffer[i]);
362         }
363         printk("\n");
364 #endif
365
366         return rc;
367 }
368
369 static u32 scx200_acb_func(struct i2c_adapter *adapter)
370 {
371         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
372                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
373                I2C_FUNC_SMBUS_BLOCK_DATA;
374 }
375
376 /* For now, we only handle combined mode (smbus) */
377 static struct i2c_algorithm scx200_acb_algorithm = {
378         .smbus_xfer     = scx200_acb_smbus_xfer,
379         .functionality  = scx200_acb_func,
380 };
381
382 static struct scx200_acb_iface *scx200_acb_list;
383 static DECLARE_MUTEX(scx200_acb_list_mutex);
384
385 static int scx200_acb_probe(struct scx200_acb_iface *iface)
386 {
387         u8 val;
388
389         /* Disable the ACCESS.bus device and Configure the SCL
390            frequency: 16 clock cycles */
391         outb(0x70, ACBCTL2);
392
393         if (inb(ACBCTL2) != 0x70) {
394                 pr_debug(NAME ": ACBCTL2 readback failed\n");
395                 return -ENXIO;
396         }
397
398         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
399
400         val = inb(ACBCTL1);
401         if (val) {
402                 pr_debug(NAME ": disabled, but ACBCTL1=0x%02x\n",
403                         val);
404                 return -ENXIO;
405         }
406
407         outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
408
409         outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
410
411         val = inb(ACBCTL1);
412         if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
413                 pr_debug(NAME ": enabled, but NMINTE won't be set, "
414                          "ACBCTL1=0x%02x\n", val);
415                 return -ENXIO;
416         }
417
418         return 0;
419 }
420
421 static int  __init scx200_acb_create(const char *text, int base, int index)
422 {
423         struct scx200_acb_iface *iface;
424         struct i2c_adapter *adapter;
425         int rc;
426         char description[64];
427
428         iface = kzalloc(sizeof(*iface), GFP_KERNEL);
429         if (!iface) {
430                 printk(KERN_ERR NAME ": can't allocate memory\n");
431                 rc = -ENOMEM;
432                 goto errout;
433         }
434
435         adapter = &iface->adapter;
436         i2c_set_adapdata(adapter, iface);
437         snprintf(adapter->name, I2C_NAME_SIZE, "%s ACB%d", text, index);
438         adapter->owner = THIS_MODULE;
439         adapter->id = I2C_HW_SMBUS_SCX200;
440         adapter->algo = &scx200_acb_algorithm;
441         adapter->class = I2C_CLASS_HWMON;
442
443         init_MUTEX(&iface->sem);
444
445         snprintf(description, sizeof(description), "%s ACCESS.bus [%s]",
446                  text, adapter->name);
447
448         if (request_region(base, 8, description) == 0) {
449                 printk(KERN_ERR NAME ": can't allocate io 0x%x-0x%x\n",
450                         base, base + 8-1);
451                 rc = -EBUSY;
452                 goto errout_free;
453         }
454         iface->base = base;
455
456         rc = scx200_acb_probe(iface);
457         if (rc) {
458                 printk(KERN_WARNING NAME ": probe failed\n");
459                 goto errout_release;
460         }
461
462         scx200_acb_reset(iface);
463
464         if (i2c_add_adapter(adapter) < 0) {
465                 printk(KERN_ERR NAME ": failed to register\n");
466                 rc = -ENODEV;
467                 goto errout_release;
468         }
469
470         down(&scx200_acb_list_mutex);
471         iface->next = scx200_acb_list;
472         scx200_acb_list = iface;
473         up(&scx200_acb_list_mutex);
474
475         return 0;
476
477  errout_release:
478         release_region(iface->base, 8);
479  errout_free:
480         kfree(iface);
481  errout:
482         return rc;
483 }
484
485 static struct pci_device_id scx200[] = {
486         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
487         { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
488         { },
489 };
490
491 static struct pci_device_id divil_pci[] = {
492         { PCI_DEVICE(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA) },
493         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
494         { } /* NULL entry */
495 };
496
497 #define MSR_LBAR_SMB            0x5140000B
498
499 static int scx200_add_cs553x(void)
500 {
501         u32     low, hi;
502         u32     smb_base;
503
504         /* Grab & reserve the SMB I/O range */
505         rdmsr(MSR_LBAR_SMB, low, hi);
506
507         /* Check the IO mask and whether SMB is enabled */
508         if (hi != 0x0000F001) {
509                 printk(KERN_WARNING NAME ": SMBus not enabled\n");
510                 return -ENODEV;
511         }
512
513         /* SMBus IO size is 8 bytes */
514         smb_base = low & 0x0000FFF8;
515
516         return scx200_acb_create("CS5535", smb_base, 0);
517 }
518
519 static int __init scx200_acb_init(void)
520 {
521         int i;
522         int     rc = -ENODEV;
523
524         pr_debug(NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
525
526         /* Verify that this really is a SCx200 processor */
527         if (pci_dev_present(scx200)) {
528                 for (i = 0; i < MAX_DEVICES; ++i) {
529                         if (base[i] > 0)
530                                 rc = scx200_acb_create("SCx200", base[i], i);
531                 }
532         } else if (pci_dev_present(divil_pci))
533                 rc = scx200_add_cs553x();
534
535         return rc;
536 }
537
538 static void __exit scx200_acb_cleanup(void)
539 {
540         struct scx200_acb_iface *iface;
541
542         down(&scx200_acb_list_mutex);
543         while ((iface = scx200_acb_list) != NULL) {
544                 scx200_acb_list = iface->next;
545                 up(&scx200_acb_list_mutex);
546
547                 i2c_del_adapter(&iface->adapter);
548                 release_region(iface->base, 8);
549                 kfree(iface);
550                 down(&scx200_acb_list_mutex);
551         }
552         up(&scx200_acb_list_mutex);
553 }
554
555 module_init(scx200_acb_init);
556 module_exit(scx200_acb_cleanup);