1 /*
2 * PowerMac G5 SMU driver
3 *
4 * Copyright 2004 J. Mayer <l_indien@magic.fr>
5 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6 *
7 * Released under the term of the GNU GPL v2.
8 */
9
10 /*
11 * TODO:
12 * - maybe add timeout to commands ?
13 * - blocking version of time functions
14 * - polling version of i2c commands (including timer that works with
15 * interrupts off)
16 * - maybe avoid some data copies with i2c by directly using the smu cmd
17 * buffer and a lower level internal interface
18 * - understand SMU -> CPU events and implement reception of them via
19 * the userland interface
20 */
21
22 #include <linux/types.h>
23 #include <linux/kernel.h>
24 #include <linux/device.h>
25 #include <linux/dmapool.h>
26 #include <linux/bootmem.h>
27 #include <linux/vmalloc.h>
28 #include <linux/highmem.h>
29 #include <linux/jiffies.h>
30 #include <linux/interrupt.h>
31 #include <linux/rtc.h>
32 #include <linux/completion.h>
33 #include <linux/miscdevice.h>
34 #include <linux/delay.h>
35 #include <linux/sysdev.h>
36 #include <linux/poll.h>
37 #include <linux/mutex.h>
38 #include <linux/of_device.h>
39 #include <linux/of_platform.h>
40 #include <linux/slab.h>
41
42 #include <asm/byteorder.h>
43 #include <asm/io.h>
44 #include <asm/prom.h>
45 #include <asm/machdep.h>
46 #include <asm/pmac_feature.h>
47 #include <asm/smu.h>
48 #include <asm/sections.h>
49 #include <asm/abs_addr.h>
50 #include <asm/uaccess.h>
51
52 #define VERSION "0.7"
53 #define AUTHOR "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
54
55 #undef DEBUG_SMU
56
57 #ifdef DEBUG_SMU
58 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
59 #else
60 #define DPRINTK(fmt, args...) do { } while (0)
61 #endif
62
63 /*
64 * This is the command buffer passed to the SMU hardware
65 */
66 #define SMU_MAX_DATA 254
67
68 struct smu_cmd_buf {
69 u8 cmd;
70 u8 length;
71 u8 data[SMU_MAX_DATA];
72 };
73
74 struct smu_device {
75 spinlock_t lock;
76 struct device_node *of_node;
77 struct platform_device *of_dev;
78 int doorbell; /* doorbell gpio */
79 u32 __iomem *db_buf; /* doorbell buffer */
80 struct device_node *db_node;
81 unsigned int db_irq;
82 int msg;
83 struct device_node *msg_node;
84 unsigned int msg_irq;
85 struct smu_cmd_buf *cmd_buf; /* command buffer virtual */
86 u32 cmd_buf_abs; /* command buffer absolute */
87 struct list_head cmd_list;
88 struct smu_cmd *cmd_cur; /* pending command */
89 int broken_nap;
90 struct list_head cmd_i2c_list;
91 struct smu_i2c_cmd *cmd_i2c_cur; /* pending i2c command */
92 struct timer_list i2c_timer;
93 };
94
95 /*
96 * I don't think there will ever be more than one SMU, so
97 * for now, just hard code that
98 */
99 static DEFINE_MUTEX(smu_mutex);
100 static struct smu_device *smu;
101 static DEFINE_MUTEX(smu_part_access);
102 static int smu_irq_inited;
103
104 static void smu_i2c_retry(unsigned long data);
105
106 /*
107 * SMU driver low level stuff
108 */
109
smu_start_cmd(void)110 static void smu_start_cmd(void)
111 {
112 unsigned long faddr, fend;
113 struct smu_cmd *cmd;
114
115 if (list_empty(&smu->cmd_list))
116 return;
117
118 /* Fetch first command in queue */
119 cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
120 smu->cmd_cur = cmd;
121 list_del(&cmd->link);
122
123 DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
124 cmd->data_len);
125 DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
126 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
127 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
128 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
129 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
130
131 /* Fill the SMU command buffer */
132 smu->cmd_buf->cmd = cmd->cmd;
133 smu->cmd_buf->length = cmd->data_len;
134 memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
135
136 /* Flush command and data to RAM */
137 faddr = (unsigned long)smu->cmd_buf;
138 fend = faddr + smu->cmd_buf->length + 2;
139 flush_inval_dcache_range(faddr, fend);
140
141
142 /* We also disable NAP mode for the duration of the command
143 * on U3 based machines.
144 * This is slightly racy as it can be written back to 1 by a sysctl
145 * but that never happens in practice. There seem to be an issue with
146 * U3 based machines such as the iMac G5 where napping for the
147 * whole duration of the command prevents the SMU from fetching it
148 * from memory. This might be related to the strange i2c based
149 * mechanism the SMU uses to access memory.
150 */
151 if (smu->broken_nap)
152 powersave_nap = 0;
153
154 /* This isn't exactly a DMA mapping here, I suspect
155 * the SMU is actually communicating with us via i2c to the
156 * northbridge or the CPU to access RAM.
157 */
158 writel(smu->cmd_buf_abs, smu->db_buf);
159
160 /* Ring the SMU doorbell */
161 pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
162 }
163
164
smu_db_intr(int irq,void * arg)165 static irqreturn_t smu_db_intr(int irq, void *arg)
166 {
167 unsigned long flags;
168 struct smu_cmd *cmd;
169 void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
170 void *misc = NULL;
171 u8 gpio;
172 int rc = 0;
173
174 /* SMU completed the command, well, we hope, let's make sure
175 * of it
176 */
177 spin_lock_irqsave(&smu->lock, flags);
178
179 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
180 if ((gpio & 7) != 7) {
181 spin_unlock_irqrestore(&smu->lock, flags);
182 return IRQ_HANDLED;
183 }
184
185 cmd = smu->cmd_cur;
186 smu->cmd_cur = NULL;
187 if (cmd == NULL)
188 goto bail;
189
190 if (rc == 0) {
191 unsigned long faddr;
192 int reply_len;
193 u8 ack;
194
195 /* CPU might have brought back the cache line, so we need
196 * to flush again before peeking at the SMU response. We
197 * flush the entire buffer for now as we haven't read the
198 * reply length (it's only 2 cache lines anyway)
199 */
200 faddr = (unsigned long)smu->cmd_buf;
201 flush_inval_dcache_range(faddr, faddr + 256);
202
203 /* Now check ack */
204 ack = (~cmd->cmd) & 0xff;
205 if (ack != smu->cmd_buf->cmd) {
206 DPRINTK("SMU: incorrect ack, want %x got %x\n",
207 ack, smu->cmd_buf->cmd);
208 rc = -EIO;
209 }
210 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
211 DPRINTK("SMU: reply len: %d\n", reply_len);
212 if (reply_len > cmd->reply_len) {
213 printk(KERN_WARNING "SMU: reply buffer too small,"
214 "got %d bytes for a %d bytes buffer\n",
215 reply_len, cmd->reply_len);
216 reply_len = cmd->reply_len;
217 }
218 cmd->reply_len = reply_len;
219 if (cmd->reply_buf && reply_len)
220 memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
221 }
222
223 /* Now complete the command. Write status last in order as we lost
224 * ownership of the command structure as soon as it's no longer -1
225 */
226 done = cmd->done;
227 misc = cmd->misc;
228 mb();
229 cmd->status = rc;
230
231 /* Re-enable NAP mode */
232 if (smu->broken_nap)
233 powersave_nap = 1;
234 bail:
235 /* Start next command if any */
236 smu_start_cmd();
237 spin_unlock_irqrestore(&smu->lock, flags);
238
239 /* Call command completion handler if any */
240 if (done)
241 done(cmd, misc);
242
243 /* It's an edge interrupt, nothing to do */
244 return IRQ_HANDLED;
245 }
246
247
smu_msg_intr(int irq,void * arg)248 static irqreturn_t smu_msg_intr(int irq, void *arg)
249 {
250 /* I don't quite know what to do with this one, we seem to never
251 * receive it, so I suspect we have to arm it someway in the SMU
252 * to start getting events that way.
253 */
254
255 printk(KERN_INFO "SMU: message interrupt !\n");
256
257 /* It's an edge interrupt, nothing to do */
258 return IRQ_HANDLED;
259 }
260
261
262 /*
263 * Queued command management.
264 *
265 */
266
smu_queue_cmd(struct smu_cmd * cmd)267 int smu_queue_cmd(struct smu_cmd *cmd)
268 {
269 unsigned long flags;
270
271 if (smu == NULL)
272 return -ENODEV;
273 if (cmd->data_len > SMU_MAX_DATA ||
274 cmd->reply_len > SMU_MAX_DATA)
275 return -EINVAL;
276
277 cmd->status = 1;
278 spin_lock_irqsave(&smu->lock, flags);
279 list_add_tail(&cmd->link, &smu->cmd_list);
280 if (smu->cmd_cur == NULL)
281 smu_start_cmd();
282 spin_unlock_irqrestore(&smu->lock, flags);
283
284 /* Workaround for early calls when irq isn't available */
285 if (!smu_irq_inited || smu->db_irq == NO_IRQ)
286 smu_spinwait_cmd(cmd);
287
288 return 0;
289 }
290 EXPORT_SYMBOL(smu_queue_cmd);
291
292
smu_queue_simple(struct smu_simple_cmd * scmd,u8 command,unsigned int data_len,void (* done)(struct smu_cmd * cmd,void * misc),void * misc,...)293 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
294 unsigned int data_len,
295 void (*done)(struct smu_cmd *cmd, void *misc),
296 void *misc, ...)
297 {
298 struct smu_cmd *cmd = &scmd->cmd;
299 va_list list;
300 int i;
301
302 if (data_len > sizeof(scmd->buffer))
303 return -EINVAL;
304
305 memset(scmd, 0, sizeof(*scmd));
306 cmd->cmd = command;
307 cmd->data_len = data_len;
308 cmd->data_buf = scmd->buffer;
309 cmd->reply_len = sizeof(scmd->buffer);
310 cmd->reply_buf = scmd->buffer;
311 cmd->done = done;
312 cmd->misc = misc;
313
314 va_start(list, misc);
315 for (i = 0; i < data_len; ++i)
316 scmd->buffer[i] = (u8)va_arg(list, int);
317 va_end(list);
318
319 return smu_queue_cmd(cmd);
320 }
321 EXPORT_SYMBOL(smu_queue_simple);
322
323
smu_poll(void)324 void smu_poll(void)
325 {
326 u8 gpio;
327
328 if (smu == NULL)
329 return;
330
331 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
332 if ((gpio & 7) == 7)
333 smu_db_intr(smu->db_irq, smu);
334 }
335 EXPORT_SYMBOL(smu_poll);
336
337
smu_done_complete(struct smu_cmd * cmd,void * misc)338 void smu_done_complete(struct smu_cmd *cmd, void *misc)
339 {
340 struct completion *comp = misc;
341
342 complete(comp);
343 }
344 EXPORT_SYMBOL(smu_done_complete);
345
346
smu_spinwait_cmd(struct smu_cmd * cmd)347 void smu_spinwait_cmd(struct smu_cmd *cmd)
348 {
349 while(cmd->status == 1)
350 smu_poll();
351 }
352 EXPORT_SYMBOL(smu_spinwait_cmd);
353
354
355 /* RTC low level commands */
bcd2hex(int n)356 static inline int bcd2hex (int n)
357 {
358 return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
359 }
360
361
hex2bcd(int n)362 static inline int hex2bcd (int n)
363 {
364 return ((n / 10) << 4) + (n % 10);
365 }
366
367
smu_fill_set_rtc_cmd(struct smu_cmd_buf * cmd_buf,struct rtc_time * time)368 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
369 struct rtc_time *time)
370 {
371 cmd_buf->cmd = 0x8e;
372 cmd_buf->length = 8;
373 cmd_buf->data[0] = 0x80;
374 cmd_buf->data[1] = hex2bcd(time->tm_sec);
375 cmd_buf->data[2] = hex2bcd(time->tm_min);
376 cmd_buf->data[3] = hex2bcd(time->tm_hour);
377 cmd_buf->data[4] = time->tm_wday;
378 cmd_buf->data[5] = hex2bcd(time->tm_mday);
379 cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
380 cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
381 }
382
383
smu_get_rtc_time(struct rtc_time * time,int spinwait)384 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
385 {
386 struct smu_simple_cmd cmd;
387 int rc;
388
389 if (smu == NULL)
390 return -ENODEV;
391
392 memset(time, 0, sizeof(struct rtc_time));
393 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
394 SMU_CMD_RTC_GET_DATETIME);
395 if (rc)
396 return rc;
397 smu_spinwait_simple(&cmd);
398
399 time->tm_sec = bcd2hex(cmd.buffer[0]);
400 time->tm_min = bcd2hex(cmd.buffer[1]);
401 time->tm_hour = bcd2hex(cmd.buffer[2]);
402 time->tm_wday = bcd2hex(cmd.buffer[3]);
403 time->tm_mday = bcd2hex(cmd.buffer[4]);
404 time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
405 time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
406
407 return 0;
408 }
409
410
smu_set_rtc_time(struct rtc_time * time,int spinwait)411 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
412 {
413 struct smu_simple_cmd cmd;
414 int rc;
415
416 if (smu == NULL)
417 return -ENODEV;
418
419 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
420 SMU_CMD_RTC_SET_DATETIME,
421 hex2bcd(time->tm_sec),
422 hex2bcd(time->tm_min),
423 hex2bcd(time->tm_hour),
424 time->tm_wday,
425 hex2bcd(time->tm_mday),
426 hex2bcd(time->tm_mon) + 1,
427 hex2bcd(time->tm_year - 100));
428 if (rc)
429 return rc;
430 smu_spinwait_simple(&cmd);
431
432 return 0;
433 }
434
435
smu_shutdown(void)436 void smu_shutdown(void)
437 {
438 struct smu_simple_cmd cmd;
439
440 if (smu == NULL)
441 return;
442
443 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
444 'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
445 return;
446 smu_spinwait_simple(&cmd);
447 for (;;)
448 ;
449 }
450
451
smu_restart(void)452 void smu_restart(void)
453 {
454 struct smu_simple_cmd cmd;
455
456 if (smu == NULL)
457 return;
458
459 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
460 'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
461 return;
462 smu_spinwait_simple(&cmd);
463 for (;;)
464 ;
465 }
466
467
smu_present(void)468 int smu_present(void)
469 {
470 return smu != NULL;
471 }
472 EXPORT_SYMBOL(smu_present);
473
474
smu_init(void)475 int __init smu_init (void)
476 {
477 struct device_node *np;
478 const u32 *data;
479 int ret = 0;
480
481 np = of_find_node_by_type(NULL, "smu");
482 if (np == NULL)
483 return -ENODEV;
484
485 printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
486
487 if (smu_cmdbuf_abs == 0) {
488 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
489 ret = -EINVAL;
490 goto fail_np;
491 }
492
493 smu = alloc_bootmem(sizeof(struct smu_device));
494
495 spin_lock_init(&smu->lock);
496 INIT_LIST_HEAD(&smu->cmd_list);
497 INIT_LIST_HEAD(&smu->cmd_i2c_list);
498 smu->of_node = np;
499 smu->db_irq = NO_IRQ;
500 smu->msg_irq = NO_IRQ;
501
502 /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
503 * 32 bits value safely
504 */
505 smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
506 smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
507
508 smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
509 if (smu->db_node == NULL) {
510 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
511 ret = -ENXIO;
512 goto fail_bootmem;
513 }
514 data = of_get_property(smu->db_node, "reg", NULL);
515 if (data == NULL) {
516 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
517 ret = -ENXIO;
518 goto fail_db_node;
519 }
520
521 /* Current setup has one doorbell GPIO that does both doorbell
522 * and ack. GPIOs are at 0x50, best would be to find that out
523 * in the device-tree though.
524 */
525 smu->doorbell = *data;
526 if (smu->doorbell < 0x50)
527 smu->doorbell += 0x50;
528
529 /* Now look for the smu-interrupt GPIO */
530 do {
531 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
532 if (smu->msg_node == NULL)
533 break;
534 data = of_get_property(smu->msg_node, "reg", NULL);
535 if (data == NULL) {
536 of_node_put(smu->msg_node);
537 smu->msg_node = NULL;
538 break;
539 }
540 smu->msg = *data;
541 if (smu->msg < 0x50)
542 smu->msg += 0x50;
543 } while(0);
544
545 /* Doorbell buffer is currently hard-coded, I didn't find a proper
546 * device-tree entry giving the address. Best would probably to use
547 * an offset for K2 base though, but let's do it that way for now.
548 */
549 smu->db_buf = ioremap(0x8000860c, 0x1000);
550 if (smu->db_buf == NULL) {
551 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
552 ret = -ENXIO;
553 goto fail_msg_node;
554 }
555
556 /* U3 has an issue with NAP mode when issuing SMU commands */
557 smu->broken_nap = pmac_get_uninorth_variant() < 4;
558 if (smu->broken_nap)
559 printk(KERN_INFO "SMU: using NAP mode workaround\n");
560
561 sys_ctrler = SYS_CTRLER_SMU;
562 return 0;
563
564 fail_msg_node:
565 if (smu->msg_node)
566 of_node_put(smu->msg_node);
567 fail_db_node:
568 of_node_put(smu->db_node);
569 fail_bootmem:
570 free_bootmem((unsigned long)smu, sizeof(struct smu_device));
571 smu = NULL;
572 fail_np:
573 of_node_put(np);
574 return ret;
575 }
576
577
smu_late_init(void)578 static int smu_late_init(void)
579 {
580 if (!smu)
581 return 0;
582
583 init_timer(&smu->i2c_timer);
584 smu->i2c_timer.function = smu_i2c_retry;
585 smu->i2c_timer.data = (unsigned long)smu;
586
587 if (smu->db_node) {
588 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
589 if (smu->db_irq == NO_IRQ)
590 printk(KERN_ERR "smu: failed to map irq for node %s\n",
591 smu->db_node->full_name);
592 }
593 if (smu->msg_node) {
594 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
595 if (smu->msg_irq == NO_IRQ)
596 printk(KERN_ERR "smu: failed to map irq for node %s\n",
597 smu->msg_node->full_name);
598 }
599
600 /*
601 * Try to request the interrupts
602 */
603
604 if (smu->db_irq != NO_IRQ) {
605 if (request_irq(smu->db_irq, smu_db_intr,
606 IRQF_SHARED, "SMU doorbell", smu) < 0) {
607 printk(KERN_WARNING "SMU: can't "
608 "request interrupt %d\n",
609 smu->db_irq);
610 smu->db_irq = NO_IRQ;
611 }
612 }
613
614 if (smu->msg_irq != NO_IRQ) {
615 if (request_irq(smu->msg_irq, smu_msg_intr,
616 IRQF_SHARED, "SMU message", smu) < 0) {
617 printk(KERN_WARNING "SMU: can't "
618 "request interrupt %d\n",
619 smu->msg_irq);
620 smu->msg_irq = NO_IRQ;
621 }
622 }
623
624 smu_irq_inited = 1;
625 return 0;
626 }
627 /* This has to be before arch_initcall as the low i2c stuff relies on the
628 * above having been done before we reach arch_initcalls
629 */
630 core_initcall(smu_late_init);
631
632 /*
633 * sysfs visibility
634 */
635
smu_expose_childs(struct work_struct * unused)636 static void smu_expose_childs(struct work_struct *unused)
637 {
638 struct device_node *np;
639
640 for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
641 if (of_device_is_compatible(np, "smu-sensors"))
642 of_platform_device_create(np, "smu-sensors",
643 &smu->of_dev->dev);
644 }
645
646 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
647
smu_platform_probe(struct platform_device * dev)648 static int smu_platform_probe(struct platform_device* dev)
649 {
650 if (!smu)
651 return -ENODEV;
652 smu->of_dev = dev;
653
654 /*
655 * Ok, we are matched, now expose all i2c busses. We have to defer
656 * that unfortunately or it would deadlock inside the device model
657 */
658 schedule_work(&smu_expose_childs_work);
659
660 return 0;
661 }
662
663 static const struct of_device_id smu_platform_match[] =
664 {
665 {
666 .type = "smu",
667 },
668 {},
669 };
670
671 static struct platform_driver smu_of_platform_driver =
672 {
673 .driver = {
674 .name = "smu",
675 .owner = THIS_MODULE,
676 .of_match_table = smu_platform_match,
677 },
678 .probe = smu_platform_probe,
679 };
680
smu_init_sysfs(void)681 static int __init smu_init_sysfs(void)
682 {
683 /*
684 * Due to sysfs bogosity, a sysdev is not a real device, so
685 * we should in fact create both if we want sysdev semantics
686 * for power management.
687 * For now, we don't power manage machines with an SMU chip,
688 * I'm a bit too far from figuring out how that works with those
689 * new chipsets, but that will come back and bite us
690 */
691 platform_driver_register(&smu_of_platform_driver);
692 return 0;
693 }
694
695 device_initcall(smu_init_sysfs);
696
smu_get_ofdev(void)697 struct platform_device *smu_get_ofdev(void)
698 {
699 if (!smu)
700 return NULL;
701 return smu->of_dev;
702 }
703
704 EXPORT_SYMBOL_GPL(smu_get_ofdev);
705
706 /*
707 * i2c interface
708 */
709
smu_i2c_complete_command(struct smu_i2c_cmd * cmd,int fail)710 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
711 {
712 void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
713 void *misc = cmd->misc;
714 unsigned long flags;
715
716 /* Check for read case */
717 if (!fail && cmd->read) {
718 if (cmd->pdata[0] < 1)
719 fail = 1;
720 else
721 memcpy(cmd->info.data, &cmd->pdata[1],
722 cmd->info.datalen);
723 }
724
725 DPRINTK("SMU: completing, success: %d\n", !fail);
726
727 /* Update status and mark no pending i2c command with lock
728 * held so nobody comes in while we dequeue an eventual
729 * pending next i2c command
730 */
731 spin_lock_irqsave(&smu->lock, flags);
732 smu->cmd_i2c_cur = NULL;
733 wmb();
734 cmd->status = fail ? -EIO : 0;
735
736 /* Is there another i2c command waiting ? */
737 if (!list_empty(&smu->cmd_i2c_list)) {
738 struct smu_i2c_cmd *newcmd;
739
740 /* Fetch it, new current, remove from list */
741 newcmd = list_entry(smu->cmd_i2c_list.next,
742 struct smu_i2c_cmd, link);
743 smu->cmd_i2c_cur = newcmd;
744 list_del(&cmd->link);
745
746 /* Queue with low level smu */
747 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
748 if (smu->cmd_cur == NULL)
749 smu_start_cmd();
750 }
751 spin_unlock_irqrestore(&smu->lock, flags);
752
753 /* Call command completion handler if any */
754 if (done)
755 done(cmd, misc);
756
757 }
758
759
smu_i2c_retry(unsigned long data)760 static void smu_i2c_retry(unsigned long data)
761 {
762 struct smu_i2c_cmd *cmd = smu->cmd_i2c_cur;
763
764 DPRINTK("SMU: i2c failure, requeuing...\n");
765
766 /* requeue command simply by resetting reply_len */
767 cmd->pdata[0] = 0xff;
768 cmd->scmd.reply_len = sizeof(cmd->pdata);
769 smu_queue_cmd(&cmd->scmd);
770 }
771
772
smu_i2c_low_completion(struct smu_cmd * scmd,void * misc)773 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
774 {
775 struct smu_i2c_cmd *cmd = misc;
776 int fail = 0;
777
778 DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
779 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
780
781 /* Check for possible status */
782 if (scmd->status < 0)
783 fail = 1;
784 else if (cmd->read) {
785 if (cmd->stage == 0)
786 fail = cmd->pdata[0] != 0;
787 else
788 fail = cmd->pdata[0] >= 0x80;
789 } else {
790 fail = cmd->pdata[0] != 0;
791 }
792
793 /* Handle failures by requeuing command, after 5ms interval
794 */
795 if (fail && --cmd->retries > 0) {
796 DPRINTK("SMU: i2c failure, starting timer...\n");
797 BUG_ON(cmd != smu->cmd_i2c_cur);
798 if (!smu_irq_inited) {
799 mdelay(5);
800 smu_i2c_retry(0);
801 return;
802 }
803 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
804 return;
805 }
806
807 /* If failure or stage 1, command is complete */
808 if (fail || cmd->stage != 0) {
809 smu_i2c_complete_command(cmd, fail);
810 return;
811 }
812
813 DPRINTK("SMU: going to stage 1\n");
814
815 /* Ok, initial command complete, now poll status */
816 scmd->reply_buf = cmd->pdata;
817 scmd->reply_len = sizeof(cmd->pdata);
818 scmd->data_buf = cmd->pdata;
819 scmd->data_len = 1;
820 cmd->pdata[0] = 0;
821 cmd->stage = 1;
822 cmd->retries = 20;
823 smu_queue_cmd(scmd);
824 }
825
826
smu_queue_i2c(struct smu_i2c_cmd * cmd)827 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
828 {
829 unsigned long flags;
830
831 if (smu == NULL)
832 return -ENODEV;
833
834 /* Fill most fields of scmd */
835 cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
836 cmd->scmd.done = smu_i2c_low_completion;
837 cmd->scmd.misc = cmd;
838 cmd->scmd.reply_buf = cmd->pdata;
839 cmd->scmd.reply_len = sizeof(cmd->pdata);
840 cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
841 cmd->scmd.status = 1;
842 cmd->stage = 0;
843 cmd->pdata[0] = 0xff;
844 cmd->retries = 20;
845 cmd->status = 1;
846
847 /* Check transfer type, sanitize some "info" fields
848 * based on transfer type and do more checking
849 */
850 cmd->info.caddr = cmd->info.devaddr;
851 cmd->read = cmd->info.devaddr & 0x01;
852 switch(cmd->info.type) {
853 case SMU_I2C_TRANSFER_SIMPLE:
854 memset(&cmd->info.sublen, 0, 4);
855 break;
856 case SMU_I2C_TRANSFER_COMBINED:
857 cmd->info.devaddr &= 0xfe;
858 case SMU_I2C_TRANSFER_STDSUB:
859 if (cmd->info.sublen > 3)
860 return -EINVAL;
861 break;
862 default:
863 return -EINVAL;
864 }
865
866 /* Finish setting up command based on transfer direction
867 */
868 if (cmd->read) {
869 if (cmd->info.datalen > SMU_I2C_READ_MAX)
870 return -EINVAL;
871 memset(cmd->info.data, 0xff, cmd->info.datalen);
872 cmd->scmd.data_len = 9;
873 } else {
874 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
875 return -EINVAL;
876 cmd->scmd.data_len = 9 + cmd->info.datalen;
877 }
878
879 DPRINTK("SMU: i2c enqueuing command\n");
880 DPRINTK("SMU: %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
881 cmd->read ? "read" : "write", cmd->info.datalen,
882 cmd->info.bus, cmd->info.caddr,
883 cmd->info.subaddr[0], cmd->info.type);
884
885
886 /* Enqueue command in i2c list, and if empty, enqueue also in
887 * main command list
888 */
889 spin_lock_irqsave(&smu->lock, flags);
890 if (smu->cmd_i2c_cur == NULL) {
891 smu->cmd_i2c_cur = cmd;
892 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
893 if (smu->cmd_cur == NULL)
894 smu_start_cmd();
895 } else
896 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
897 spin_unlock_irqrestore(&smu->lock, flags);
898
899 return 0;
900 }
901
902 /*
903 * Handling of "partitions"
904 */
905
smu_read_datablock(u8 * dest,unsigned int addr,unsigned int len)906 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
907 {
908 DECLARE_COMPLETION_ONSTACK(comp);
909 unsigned int chunk;
910 struct smu_cmd cmd;
911 int rc;
912 u8 params[8];
913
914 /* We currently use a chunk size of 0xe. We could check the
915 * SMU firmware version and use bigger sizes though
916 */
917 chunk = 0xe;
918
919 while (len) {
920 unsigned int clen = min(len, chunk);
921
922 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
923 cmd.data_len = 7;
924 cmd.data_buf = params;
925 cmd.reply_len = chunk;
926 cmd.reply_buf = dest;
927 cmd.done = smu_done_complete;
928 cmd.misc = ∁
929 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
930 params[1] = 0x4;
931 *((u32 *)¶ms[2]) = addr;
932 params[6] = clen;
933
934 rc = smu_queue_cmd(&cmd);
935 if (rc)
936 return rc;
937 wait_for_completion(&comp);
938 if (cmd.status != 0)
939 return rc;
940 if (cmd.reply_len != clen) {
941 printk(KERN_DEBUG "SMU: short read in "
942 "smu_read_datablock, got: %d, want: %d\n",
943 cmd.reply_len, clen);
944 return -EIO;
945 }
946 len -= clen;
947 addr += clen;
948 dest += clen;
949 }
950 return 0;
951 }
952
smu_create_sdb_partition(int id)953 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
954 {
955 DECLARE_COMPLETION_ONSTACK(comp);
956 struct smu_simple_cmd cmd;
957 unsigned int addr, len, tlen;
958 struct smu_sdbp_header *hdr;
959 struct property *prop;
960
961 /* First query the partition info */
962 DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
963 smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
964 smu_done_complete, &comp,
965 SMU_CMD_PARTITION_LATEST, id);
966 wait_for_completion(&comp);
967 DPRINTK("SMU: done, status: %d, reply_len: %d\n",
968 cmd.cmd.status, cmd.cmd.reply_len);
969
970 /* Partition doesn't exist (or other error) */
971 if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
972 return NULL;
973
974 /* Fetch address and length from reply */
975 addr = *((u16 *)cmd.buffer);
976 len = cmd.buffer[3] << 2;
977 /* Calucluate total length to allocate, including the 17 bytes
978 * for "sdb-partition-XX" that we append at the end of the buffer
979 */
980 tlen = sizeof(struct property) + len + 18;
981
982 prop = kzalloc(tlen, GFP_KERNEL);
983 if (prop == NULL)
984 return NULL;
985 hdr = (struct smu_sdbp_header *)(prop + 1);
986 prop->name = ((char *)prop) + tlen - 18;
987 sprintf(prop->name, "sdb-partition-%02x", id);
988 prop->length = len;
989 prop->value = hdr;
990 prop->next = NULL;
991
992 /* Read the datablock */
993 if (smu_read_datablock((u8 *)hdr, addr, len)) {
994 printk(KERN_DEBUG "SMU: datablock read failed while reading "
995 "partition %02x !\n", id);
996 goto failure;
997 }
998
999 /* Got it, check a few things and create the property */
1000 if (hdr->id != id) {
1001 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1002 "%02x !\n", id, hdr->id);
1003 goto failure;
1004 }
1005 if (prom_add_property(smu->of_node, prop)) {
1006 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1007 "property !\n", id);
1008 goto failure;
1009 }
1010
1011 return hdr;
1012 failure:
1013 kfree(prop);
1014 return NULL;
1015 }
1016
1017 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1018 * when interruptible is 1
1019 */
__smu_get_sdb_partition(int id,unsigned int * size,int interruptible)1020 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1021 unsigned int *size, int interruptible)
1022 {
1023 char pname[32];
1024 const struct smu_sdbp_header *part;
1025
1026 if (!smu)
1027 return NULL;
1028
1029 sprintf(pname, "sdb-partition-%02x", id);
1030
1031 DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1032
1033 if (interruptible) {
1034 int rc;
1035 rc = mutex_lock_interruptible(&smu_part_access);
1036 if (rc)
1037 return ERR_PTR(rc);
1038 } else
1039 mutex_lock(&smu_part_access);
1040
1041 part = of_get_property(smu->of_node, pname, size);
1042 if (part == NULL) {
1043 DPRINTK("trying to extract from SMU ...\n");
1044 part = smu_create_sdb_partition(id);
1045 if (part != NULL && size)
1046 *size = part->len << 2;
1047 }
1048 mutex_unlock(&smu_part_access);
1049 return part;
1050 }
1051
smu_get_sdb_partition(int id,unsigned int * size)1052 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1053 {
1054 return __smu_get_sdb_partition(id, size, 0);
1055 }
1056 EXPORT_SYMBOL(smu_get_sdb_partition);
1057
1058
1059 /*
1060 * Userland driver interface
1061 */
1062
1063
1064 static LIST_HEAD(smu_clist);
1065 static DEFINE_SPINLOCK(smu_clist_lock);
1066
1067 enum smu_file_mode {
1068 smu_file_commands,
1069 smu_file_events,
1070 smu_file_closing
1071 };
1072
1073 struct smu_private
1074 {
1075 struct list_head list;
1076 enum smu_file_mode mode;
1077 int busy;
1078 struct smu_cmd cmd;
1079 spinlock_t lock;
1080 wait_queue_head_t wait;
1081 u8 buffer[SMU_MAX_DATA];
1082 };
1083
1084
smu_open(struct inode * inode,struct file * file)1085 static int smu_open(struct inode *inode, struct file *file)
1086 {
1087 struct smu_private *pp;
1088 unsigned long flags;
1089
1090 pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1091 if (pp == 0)
1092 return -ENOMEM;
1093 spin_lock_init(&pp->lock);
1094 pp->mode = smu_file_commands;
1095 init_waitqueue_head(&pp->wait);
1096
1097 mutex_lock(&smu_mutex);
1098 spin_lock_irqsave(&smu_clist_lock, flags);
1099 list_add(&pp->list, &smu_clist);
1100 spin_unlock_irqrestore(&smu_clist_lock, flags);
1101 file->private_data = pp;
1102 mutex_unlock(&smu_mutex);
1103
1104 return 0;
1105 }
1106
1107
smu_user_cmd_done(struct smu_cmd * cmd,void * misc)1108 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1109 {
1110 struct smu_private *pp = misc;
1111
1112 wake_up_all(&pp->wait);
1113 }
1114
1115
smu_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1116 static ssize_t smu_write(struct file *file, const char __user *buf,
1117 size_t count, loff_t *ppos)
1118 {
1119 struct smu_private *pp = file->private_data;
1120 unsigned long flags;
1121 struct smu_user_cmd_hdr hdr;
1122 int rc = 0;
1123
1124 if (pp->busy)
1125 return -EBUSY;
1126 else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1127 return -EFAULT;
1128 else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1129 pp->mode = smu_file_events;
1130 return 0;
1131 } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1132 const struct smu_sdbp_header *part;
1133 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1134 if (part == NULL)
1135 return -EINVAL;
1136 else if (IS_ERR(part))
1137 return PTR_ERR(part);
1138 return 0;
1139 } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1140 return -EINVAL;
1141 else if (pp->mode != smu_file_commands)
1142 return -EBADFD;
1143 else if (hdr.data_len > SMU_MAX_DATA)
1144 return -EINVAL;
1145
1146 spin_lock_irqsave(&pp->lock, flags);
1147 if (pp->busy) {
1148 spin_unlock_irqrestore(&pp->lock, flags);
1149 return -EBUSY;
1150 }
1151 pp->busy = 1;
1152 pp->cmd.status = 1;
1153 spin_unlock_irqrestore(&pp->lock, flags);
1154
1155 if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1156 pp->busy = 0;
1157 return -EFAULT;
1158 }
1159
1160 pp->cmd.cmd = hdr.cmd;
1161 pp->cmd.data_len = hdr.data_len;
1162 pp->cmd.reply_len = SMU_MAX_DATA;
1163 pp->cmd.data_buf = pp->buffer;
1164 pp->cmd.reply_buf = pp->buffer;
1165 pp->cmd.done = smu_user_cmd_done;
1166 pp->cmd.misc = pp;
1167 rc = smu_queue_cmd(&pp->cmd);
1168 if (rc < 0)
1169 return rc;
1170 return count;
1171 }
1172
1173
smu_read_command(struct file * file,struct smu_private * pp,char __user * buf,size_t count)1174 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1175 char __user *buf, size_t count)
1176 {
1177 DECLARE_WAITQUEUE(wait, current);
1178 struct smu_user_reply_hdr hdr;
1179 unsigned long flags;
1180 int size, rc = 0;
1181
1182 if (!pp->busy)
1183 return 0;
1184 if (count < sizeof(struct smu_user_reply_hdr))
1185 return -EOVERFLOW;
1186 spin_lock_irqsave(&pp->lock, flags);
1187 if (pp->cmd.status == 1) {
1188 if (file->f_flags & O_NONBLOCK) {
1189 spin_unlock_irqrestore(&pp->lock, flags);
1190 return -EAGAIN;
1191 }
1192 add_wait_queue(&pp->wait, &wait);
1193 for (;;) {
1194 set_current_state(TASK_INTERRUPTIBLE);
1195 rc = 0;
1196 if (pp->cmd.status != 1)
1197 break;
1198 rc = -ERESTARTSYS;
1199 if (signal_pending(current))
1200 break;
1201 spin_unlock_irqrestore(&pp->lock, flags);
1202 schedule();
1203 spin_lock_irqsave(&pp->lock, flags);
1204 }
1205 set_current_state(TASK_RUNNING);
1206 remove_wait_queue(&pp->wait, &wait);
1207 }
1208 spin_unlock_irqrestore(&pp->lock, flags);
1209 if (rc)
1210 return rc;
1211 if (pp->cmd.status != 0)
1212 pp->cmd.reply_len = 0;
1213 size = sizeof(hdr) + pp->cmd.reply_len;
1214 if (count < size)
1215 size = count;
1216 rc = size;
1217 hdr.status = pp->cmd.status;
1218 hdr.reply_len = pp->cmd.reply_len;
1219 if (copy_to_user(buf, &hdr, sizeof(hdr)))
1220 return -EFAULT;
1221 size -= sizeof(hdr);
1222 if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1223 return -EFAULT;
1224 pp->busy = 0;
1225
1226 return rc;
1227 }
1228
1229
smu_read_events(struct file * file,struct smu_private * pp,char __user * buf,size_t count)1230 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1231 char __user *buf, size_t count)
1232 {
1233 /* Not implemented */
1234 msleep_interruptible(1000);
1235 return 0;
1236 }
1237
1238
smu_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1239 static ssize_t smu_read(struct file *file, char __user *buf,
1240 size_t count, loff_t *ppos)
1241 {
1242 struct smu_private *pp = file->private_data;
1243
1244 if (pp->mode == smu_file_commands)
1245 return smu_read_command(file, pp, buf, count);
1246 if (pp->mode == smu_file_events)
1247 return smu_read_events(file, pp, buf, count);
1248
1249 return -EBADFD;
1250 }
1251
smu_fpoll(struct file * file,poll_table * wait)1252 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1253 {
1254 struct smu_private *pp = file->private_data;
1255 unsigned int mask = 0;
1256 unsigned long flags;
1257
1258 if (pp == 0)
1259 return 0;
1260
1261 if (pp->mode == smu_file_commands) {
1262 poll_wait(file, &pp->wait, wait);
1263
1264 spin_lock_irqsave(&pp->lock, flags);
1265 if (pp->busy && pp->cmd.status != 1)
1266 mask |= POLLIN;
1267 spin_unlock_irqrestore(&pp->lock, flags);
1268 } if (pp->mode == smu_file_events) {
1269 /* Not yet implemented */
1270 }
1271 return mask;
1272 }
1273
smu_release(struct inode * inode,struct file * file)1274 static int smu_release(struct inode *inode, struct file *file)
1275 {
1276 struct smu_private *pp = file->private_data;
1277 unsigned long flags;
1278 unsigned int busy;
1279
1280 if (pp == 0)
1281 return 0;
1282
1283 file->private_data = NULL;
1284
1285 /* Mark file as closing to avoid races with new request */
1286 spin_lock_irqsave(&pp->lock, flags);
1287 pp->mode = smu_file_closing;
1288 busy = pp->busy;
1289
1290 /* Wait for any pending request to complete */
1291 if (busy && pp->cmd.status == 1) {
1292 DECLARE_WAITQUEUE(wait, current);
1293
1294 add_wait_queue(&pp->wait, &wait);
1295 for (;;) {
1296 set_current_state(TASK_UNINTERRUPTIBLE);
1297 if (pp->cmd.status != 1)
1298 break;
1299 spin_unlock_irqrestore(&pp->lock, flags);
1300 schedule();
1301 spin_lock_irqsave(&pp->lock, flags);
1302 }
1303 set_current_state(TASK_RUNNING);
1304 remove_wait_queue(&pp->wait, &wait);
1305 }
1306 spin_unlock_irqrestore(&pp->lock, flags);
1307
1308 spin_lock_irqsave(&smu_clist_lock, flags);
1309 list_del(&pp->list);
1310 spin_unlock_irqrestore(&smu_clist_lock, flags);
1311 kfree(pp);
1312
1313 return 0;
1314 }
1315
1316
1317 static const struct file_operations smu_device_fops = {
1318 .llseek = no_llseek,
1319 .read = smu_read,
1320 .write = smu_write,
1321 .poll = smu_fpoll,
1322 .open = smu_open,
1323 .release = smu_release,
1324 };
1325
1326 static struct miscdevice pmu_device = {
1327 MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1328 };
1329
smu_device_init(void)1330 static int smu_device_init(void)
1331 {
1332 if (!smu)
1333 return -ENODEV;
1334 if (misc_register(&pmu_device) < 0)
1335 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1336 return 0;
1337 }
1338 device_initcall(smu_device_init);
1339