xref: /linux/drivers/macintosh/smu.c (revision d060296cc0300ae8ed08004ebd3994bf325fa257)
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/poll.h>
36 #include <linux/mutex.h>
37 #include <linux/of_device.h>
38 #include <linux/of_irq.h>
39 #include <linux/of_platform.h>
40 #include <linux/slab.h>
41 #include <linux/memblock.h>
42 #include <linux/sched/signal.h>
43 
44 #include <asm/byteorder.h>
45 #include <asm/io.h>
46 #include <asm/prom.h>
47 #include <asm/machdep.h>
48 #include <asm/pmac_feature.h>
49 #include <asm/smu.h>
50 #include <asm/sections.h>
51 #include <linux/uaccess.h>
52 
53 #define VERSION "0.7"
54 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
55 
56 #undef DEBUG_SMU
57 
58 #ifdef DEBUG_SMU
59 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
60 #else
61 #define DPRINTK(fmt, args...) do { } while (0)
62 #endif
63 
64 /*
65  * This is the command buffer passed to the SMU hardware
66  */
67 #define SMU_MAX_DATA	254
68 
69 struct smu_cmd_buf {
70 	u8 cmd;
71 	u8 length;
72 	u8 data[SMU_MAX_DATA];
73 };
74 
75 struct smu_device {
76 	spinlock_t		lock;
77 	struct device_node	*of_node;
78 	struct platform_device	*of_dev;
79 	int			doorbell;	/* doorbell gpio */
80 	u32 __iomem		*db_buf;	/* doorbell buffer */
81 	struct device_node	*db_node;
82 	unsigned int		db_irq;
83 	int			msg;
84 	struct device_node	*msg_node;
85 	unsigned int		msg_irq;
86 	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
87 	u32			cmd_buf_abs;	/* command buffer absolute */
88 	struct list_head	cmd_list;
89 	struct smu_cmd		*cmd_cur;	/* pending command */
90 	int			broken_nap;
91 	struct list_head	cmd_i2c_list;
92 	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
93 	struct timer_list	i2c_timer;
94 };
95 
96 /*
97  * I don't think there will ever be more than one SMU, so
98  * for now, just hard code that
99  */
100 static DEFINE_MUTEX(smu_mutex);
101 static struct smu_device	*smu;
102 static DEFINE_MUTEX(smu_part_access);
103 static int smu_irq_inited;
104 static unsigned long smu_cmdbuf_abs;
105 
106 static void smu_i2c_retry(unsigned long data);
107 
108 /*
109  * SMU driver low level stuff
110  */
111 
112 static void smu_start_cmd(void)
113 {
114 	unsigned long faddr, fend;
115 	struct smu_cmd *cmd;
116 
117 	if (list_empty(&smu->cmd_list))
118 		return;
119 
120 	/* Fetch first command in queue */
121 	cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
122 	smu->cmd_cur = cmd;
123 	list_del(&cmd->link);
124 
125 	DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
126 		cmd->data_len);
127 	DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
128 
129 	/* Fill the SMU command buffer */
130 	smu->cmd_buf->cmd = cmd->cmd;
131 	smu->cmd_buf->length = cmd->data_len;
132 	memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
133 
134 	/* Flush command and data to RAM */
135 	faddr = (unsigned long)smu->cmd_buf;
136 	fend = faddr + smu->cmd_buf->length + 2;
137 	flush_inval_dcache_range(faddr, fend);
138 
139 
140 	/* We also disable NAP mode for the duration of the command
141 	 * on U3 based machines.
142 	 * This is slightly racy as it can be written back to 1 by a sysctl
143 	 * but that never happens in practice. There seem to be an issue with
144 	 * U3 based machines such as the iMac G5 where napping for the
145 	 * whole duration of the command prevents the SMU from fetching it
146 	 * from memory. This might be related to the strange i2c based
147 	 * mechanism the SMU uses to access memory.
148 	 */
149 	if (smu->broken_nap)
150 		powersave_nap = 0;
151 
152 	/* This isn't exactly a DMA mapping here, I suspect
153 	 * the SMU is actually communicating with us via i2c to the
154 	 * northbridge or the CPU to access RAM.
155 	 */
156 	writel(smu->cmd_buf_abs, smu->db_buf);
157 
158 	/* Ring the SMU doorbell */
159 	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
160 }
161 
162 
163 static irqreturn_t smu_db_intr(int irq, void *arg)
164 {
165 	unsigned long flags;
166 	struct smu_cmd *cmd;
167 	void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
168 	void *misc = NULL;
169 	u8 gpio;
170 	int rc = 0;
171 
172 	/* SMU completed the command, well, we hope, let's make sure
173 	 * of it
174 	 */
175 	spin_lock_irqsave(&smu->lock, flags);
176 
177 	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
178 	if ((gpio & 7) != 7) {
179 		spin_unlock_irqrestore(&smu->lock, flags);
180 		return IRQ_HANDLED;
181 	}
182 
183 	cmd = smu->cmd_cur;
184 	smu->cmd_cur = NULL;
185 	if (cmd == NULL)
186 		goto bail;
187 
188 	if (rc == 0) {
189 		unsigned long faddr;
190 		int reply_len;
191 		u8 ack;
192 
193 		/* CPU might have brought back the cache line, so we need
194 		 * to flush again before peeking at the SMU response. We
195 		 * flush the entire buffer for now as we haven't read the
196 		 * reply length (it's only 2 cache lines anyway)
197 		 */
198 		faddr = (unsigned long)smu->cmd_buf;
199 		flush_inval_dcache_range(faddr, faddr + 256);
200 
201 		/* Now check ack */
202 		ack = (~cmd->cmd) & 0xff;
203 		if (ack != smu->cmd_buf->cmd) {
204 			DPRINTK("SMU: incorrect ack, want %x got %x\n",
205 				ack, smu->cmd_buf->cmd);
206 			rc = -EIO;
207 		}
208 		reply_len = rc == 0 ? smu->cmd_buf->length : 0;
209 		DPRINTK("SMU: reply len: %d\n", reply_len);
210 		if (reply_len > cmd->reply_len) {
211 			printk(KERN_WARNING "SMU: reply buffer too small,"
212 			       "got %d bytes for a %d bytes buffer\n",
213 			       reply_len, cmd->reply_len);
214 			reply_len = cmd->reply_len;
215 		}
216 		cmd->reply_len = reply_len;
217 		if (cmd->reply_buf && reply_len)
218 			memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
219 	}
220 
221 	/* Now complete the command. Write status last in order as we lost
222 	 * ownership of the command structure as soon as it's no longer -1
223 	 */
224 	done = cmd->done;
225 	misc = cmd->misc;
226 	mb();
227 	cmd->status = rc;
228 
229 	/* Re-enable NAP mode */
230 	if (smu->broken_nap)
231 		powersave_nap = 1;
232  bail:
233 	/* Start next command if any */
234 	smu_start_cmd();
235 	spin_unlock_irqrestore(&smu->lock, flags);
236 
237 	/* Call command completion handler if any */
238 	if (done)
239 		done(cmd, misc);
240 
241 	/* It's an edge interrupt, nothing to do */
242 	return IRQ_HANDLED;
243 }
244 
245 
246 static irqreturn_t smu_msg_intr(int irq, void *arg)
247 {
248 	/* I don't quite know what to do with this one, we seem to never
249 	 * receive it, so I suspect we have to arm it someway in the SMU
250 	 * to start getting events that way.
251 	 */
252 
253 	printk(KERN_INFO "SMU: message interrupt !\n");
254 
255 	/* It's an edge interrupt, nothing to do */
256 	return IRQ_HANDLED;
257 }
258 
259 
260 /*
261  * Queued command management.
262  *
263  */
264 
265 int smu_queue_cmd(struct smu_cmd *cmd)
266 {
267 	unsigned long flags;
268 
269 	if (smu == NULL)
270 		return -ENODEV;
271 	if (cmd->data_len > SMU_MAX_DATA ||
272 	    cmd->reply_len > SMU_MAX_DATA)
273 		return -EINVAL;
274 
275 	cmd->status = 1;
276 	spin_lock_irqsave(&smu->lock, flags);
277 	list_add_tail(&cmd->link, &smu->cmd_list);
278 	if (smu->cmd_cur == NULL)
279 		smu_start_cmd();
280 	spin_unlock_irqrestore(&smu->lock, flags);
281 
282 	/* Workaround for early calls when irq isn't available */
283 	if (!smu_irq_inited || !smu->db_irq)
284 		smu_spinwait_cmd(cmd);
285 
286 	return 0;
287 }
288 EXPORT_SYMBOL(smu_queue_cmd);
289 
290 
291 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
292 		     unsigned int data_len,
293 		     void (*done)(struct smu_cmd *cmd, void *misc),
294 		     void *misc, ...)
295 {
296 	struct smu_cmd *cmd = &scmd->cmd;
297 	va_list list;
298 	int i;
299 
300 	if (data_len > sizeof(scmd->buffer))
301 		return -EINVAL;
302 
303 	memset(scmd, 0, sizeof(*scmd));
304 	cmd->cmd = command;
305 	cmd->data_len = data_len;
306 	cmd->data_buf = scmd->buffer;
307 	cmd->reply_len = sizeof(scmd->buffer);
308 	cmd->reply_buf = scmd->buffer;
309 	cmd->done = done;
310 	cmd->misc = misc;
311 
312 	va_start(list, misc);
313 	for (i = 0; i < data_len; ++i)
314 		scmd->buffer[i] = (u8)va_arg(list, int);
315 	va_end(list);
316 
317 	return smu_queue_cmd(cmd);
318 }
319 EXPORT_SYMBOL(smu_queue_simple);
320 
321 
322 void smu_poll(void)
323 {
324 	u8 gpio;
325 
326 	if (smu == NULL)
327 		return;
328 
329 	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
330 	if ((gpio & 7) == 7)
331 		smu_db_intr(smu->db_irq, smu);
332 }
333 EXPORT_SYMBOL(smu_poll);
334 
335 
336 void smu_done_complete(struct smu_cmd *cmd, void *misc)
337 {
338 	struct completion *comp = misc;
339 
340 	complete(comp);
341 }
342 EXPORT_SYMBOL(smu_done_complete);
343 
344 
345 void smu_spinwait_cmd(struct smu_cmd *cmd)
346 {
347 	while(cmd->status == 1)
348 		smu_poll();
349 }
350 EXPORT_SYMBOL(smu_spinwait_cmd);
351 
352 
353 /* RTC low level commands */
354 static inline int bcd2hex (int n)
355 {
356 	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
357 }
358 
359 
360 static inline int hex2bcd (int n)
361 {
362 	return ((n / 10) << 4) + (n % 10);
363 }
364 
365 
366 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
367 					struct rtc_time *time)
368 {
369 	cmd_buf->cmd = 0x8e;
370 	cmd_buf->length = 8;
371 	cmd_buf->data[0] = 0x80;
372 	cmd_buf->data[1] = hex2bcd(time->tm_sec);
373 	cmd_buf->data[2] = hex2bcd(time->tm_min);
374 	cmd_buf->data[3] = hex2bcd(time->tm_hour);
375 	cmd_buf->data[4] = time->tm_wday;
376 	cmd_buf->data[5] = hex2bcd(time->tm_mday);
377 	cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
378 	cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
379 }
380 
381 
382 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
383 {
384 	struct smu_simple_cmd cmd;
385 	int rc;
386 
387 	if (smu == NULL)
388 		return -ENODEV;
389 
390 	memset(time, 0, sizeof(struct rtc_time));
391 	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
392 			      SMU_CMD_RTC_GET_DATETIME);
393 	if (rc)
394 		return rc;
395 	smu_spinwait_simple(&cmd);
396 
397 	time->tm_sec = bcd2hex(cmd.buffer[0]);
398 	time->tm_min = bcd2hex(cmd.buffer[1]);
399 	time->tm_hour = bcd2hex(cmd.buffer[2]);
400 	time->tm_wday = bcd2hex(cmd.buffer[3]);
401 	time->tm_mday = bcd2hex(cmd.buffer[4]);
402 	time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
403 	time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
404 
405 	return 0;
406 }
407 
408 
409 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
410 {
411 	struct smu_simple_cmd cmd;
412 	int rc;
413 
414 	if (smu == NULL)
415 		return -ENODEV;
416 
417 	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
418 			      SMU_CMD_RTC_SET_DATETIME,
419 			      hex2bcd(time->tm_sec),
420 			      hex2bcd(time->tm_min),
421 			      hex2bcd(time->tm_hour),
422 			      time->tm_wday,
423 			      hex2bcd(time->tm_mday),
424 			      hex2bcd(time->tm_mon) + 1,
425 			      hex2bcd(time->tm_year - 100));
426 	if (rc)
427 		return rc;
428 	smu_spinwait_simple(&cmd);
429 
430 	return 0;
431 }
432 
433 
434 void smu_shutdown(void)
435 {
436 	struct smu_simple_cmd cmd;
437 
438 	if (smu == NULL)
439 		return;
440 
441 	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
442 			     'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
443 		return;
444 	smu_spinwait_simple(&cmd);
445 	for (;;)
446 		;
447 }
448 
449 
450 void smu_restart(void)
451 {
452 	struct smu_simple_cmd cmd;
453 
454 	if (smu == NULL)
455 		return;
456 
457 	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
458 			     'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
459 		return;
460 	smu_spinwait_simple(&cmd);
461 	for (;;)
462 		;
463 }
464 
465 
466 int smu_present(void)
467 {
468 	return smu != NULL;
469 }
470 EXPORT_SYMBOL(smu_present);
471 
472 
473 int __init smu_init (void)
474 {
475 	struct device_node *np;
476 	const u32 *data;
477 	int ret = 0;
478 
479         np = of_find_node_by_type(NULL, "smu");
480         if (np == NULL)
481 		return -ENODEV;
482 
483 	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
484 
485 	/*
486 	 * SMU based G5s need some memory below 2Gb. Thankfully this is
487 	 * called at a time where memblock is still available.
488 	 */
489 	smu_cmdbuf_abs = memblock_alloc_base(4096, 4096, 0x80000000UL);
490 	if (smu_cmdbuf_abs == 0) {
491 		printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
492 		ret = -EINVAL;
493 		goto fail_np;
494 	}
495 
496 	smu = alloc_bootmem(sizeof(struct smu_device));
497 
498 	spin_lock_init(&smu->lock);
499 	INIT_LIST_HEAD(&smu->cmd_list);
500 	INIT_LIST_HEAD(&smu->cmd_i2c_list);
501 	smu->of_node = np;
502 	smu->db_irq = 0;
503 	smu->msg_irq = 0;
504 
505 	/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
506 	 * 32 bits value safely
507 	 */
508 	smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
509 	smu->cmd_buf = __va(smu_cmdbuf_abs);
510 
511 	smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
512 	if (smu->db_node == NULL) {
513 		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
514 		ret = -ENXIO;
515 		goto fail_bootmem;
516 	}
517 	data = of_get_property(smu->db_node, "reg", NULL);
518 	if (data == NULL) {
519 		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
520 		ret = -ENXIO;
521 		goto fail_db_node;
522 	}
523 
524 	/* Current setup has one doorbell GPIO that does both doorbell
525 	 * and ack. GPIOs are at 0x50, best would be to find that out
526 	 * in the device-tree though.
527 	 */
528 	smu->doorbell = *data;
529 	if (smu->doorbell < 0x50)
530 		smu->doorbell += 0x50;
531 
532 	/* Now look for the smu-interrupt GPIO */
533 	do {
534 		smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
535 		if (smu->msg_node == NULL)
536 			break;
537 		data = of_get_property(smu->msg_node, "reg", NULL);
538 		if (data == NULL) {
539 			of_node_put(smu->msg_node);
540 			smu->msg_node = NULL;
541 			break;
542 		}
543 		smu->msg = *data;
544 		if (smu->msg < 0x50)
545 			smu->msg += 0x50;
546 	} while(0);
547 
548 	/* Doorbell buffer is currently hard-coded, I didn't find a proper
549 	 * device-tree entry giving the address. Best would probably to use
550 	 * an offset for K2 base though, but let's do it that way for now.
551 	 */
552 	smu->db_buf = ioremap(0x8000860c, 0x1000);
553 	if (smu->db_buf == NULL) {
554 		printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
555 		ret = -ENXIO;
556 		goto fail_msg_node;
557 	}
558 
559 	/* U3 has an issue with NAP mode when issuing SMU commands */
560 	smu->broken_nap = pmac_get_uninorth_variant() < 4;
561 	if (smu->broken_nap)
562 		printk(KERN_INFO "SMU: using NAP mode workaround\n");
563 
564 	sys_ctrler = SYS_CTRLER_SMU;
565 	return 0;
566 
567 fail_msg_node:
568 	of_node_put(smu->msg_node);
569 fail_db_node:
570 	of_node_put(smu->db_node);
571 fail_bootmem:
572 	free_bootmem(__pa(smu), sizeof(struct smu_device));
573 	smu = NULL;
574 fail_np:
575 	of_node_put(np);
576 	return ret;
577 }
578 
579 
580 static int smu_late_init(void)
581 {
582 	if (!smu)
583 		return 0;
584 
585 	init_timer(&smu->i2c_timer);
586 	smu->i2c_timer.function = smu_i2c_retry;
587 	smu->i2c_timer.data = (unsigned long)smu;
588 
589 	if (smu->db_node) {
590 		smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
591 		if (!smu->db_irq)
592 			printk(KERN_ERR "smu: failed to map irq for node %s\n",
593 			       smu->db_node->full_name);
594 	}
595 	if (smu->msg_node) {
596 		smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
597 		if (!smu->msg_irq)
598 			printk(KERN_ERR "smu: failed to map irq for node %s\n",
599 			       smu->msg_node->full_name);
600 	}
601 
602 	/*
603 	 * Try to request the interrupts
604 	 */
605 
606 	if (smu->db_irq) {
607 		if (request_irq(smu->db_irq, smu_db_intr,
608 				IRQF_SHARED, "SMU doorbell", smu) < 0) {
609 			printk(KERN_WARNING "SMU: can't "
610 			       "request interrupt %d\n",
611 			       smu->db_irq);
612 			smu->db_irq = 0;
613 		}
614 	}
615 
616 	if (smu->msg_irq) {
617 		if (request_irq(smu->msg_irq, smu_msg_intr,
618 				IRQF_SHARED, "SMU message", smu) < 0) {
619 			printk(KERN_WARNING "SMU: can't "
620 			       "request interrupt %d\n",
621 			       smu->msg_irq);
622 			smu->msg_irq = 0;
623 		}
624 	}
625 
626 	smu_irq_inited = 1;
627 	return 0;
628 }
629 /* This has to be before arch_initcall as the low i2c stuff relies on the
630  * above having been done before we reach arch_initcalls
631  */
632 core_initcall(smu_late_init);
633 
634 /*
635  * sysfs visibility
636  */
637 
638 static void smu_expose_childs(struct work_struct *unused)
639 {
640 	struct device_node *np;
641 
642 	for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
643 		if (of_device_is_compatible(np, "smu-sensors"))
644 			of_platform_device_create(np, "smu-sensors",
645 						  &smu->of_dev->dev);
646 }
647 
648 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
649 
650 static int smu_platform_probe(struct platform_device* dev)
651 {
652 	if (!smu)
653 		return -ENODEV;
654 	smu->of_dev = dev;
655 
656 	/*
657 	 * Ok, we are matched, now expose all i2c busses. We have to defer
658 	 * that unfortunately or it would deadlock inside the device model
659 	 */
660 	schedule_work(&smu_expose_childs_work);
661 
662 	return 0;
663 }
664 
665 static const struct of_device_id smu_platform_match[] =
666 {
667 	{
668 		.type		= "smu",
669 	},
670 	{},
671 };
672 
673 static struct platform_driver smu_of_platform_driver =
674 {
675 	.driver = {
676 		.name = "smu",
677 		.of_match_table = smu_platform_match,
678 	},
679 	.probe		= smu_platform_probe,
680 };
681 
682 static int __init smu_init_sysfs(void)
683 {
684 	/*
685 	 * For now, we don't power manage machines with an SMU chip,
686 	 * I'm a bit too far from figuring out how that works with those
687 	 * new chipsets, but that will come back and bite us
688 	 */
689 	platform_driver_register(&smu_of_platform_driver);
690 	return 0;
691 }
692 
693 device_initcall(smu_init_sysfs);
694 
695 struct platform_device *smu_get_ofdev(void)
696 {
697 	if (!smu)
698 		return NULL;
699 	return smu->of_dev;
700 }
701 
702 EXPORT_SYMBOL_GPL(smu_get_ofdev);
703 
704 /*
705  * i2c interface
706  */
707 
708 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
709 {
710 	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
711 	void *misc = cmd->misc;
712 	unsigned long flags;
713 
714 	/* Check for read case */
715 	if (!fail && cmd->read) {
716 		if (cmd->pdata[0] < 1)
717 			fail = 1;
718 		else
719 			memcpy(cmd->info.data, &cmd->pdata[1],
720 			       cmd->info.datalen);
721 	}
722 
723 	DPRINTK("SMU: completing, success: %d\n", !fail);
724 
725 	/* Update status and mark no pending i2c command with lock
726 	 * held so nobody comes in while we dequeue an eventual
727 	 * pending next i2c command
728 	 */
729 	spin_lock_irqsave(&smu->lock, flags);
730 	smu->cmd_i2c_cur = NULL;
731 	wmb();
732 	cmd->status = fail ? -EIO : 0;
733 
734 	/* Is there another i2c command waiting ? */
735 	if (!list_empty(&smu->cmd_i2c_list)) {
736 		struct smu_i2c_cmd *newcmd;
737 
738 		/* Fetch it, new current, remove from list */
739 		newcmd = list_entry(smu->cmd_i2c_list.next,
740 				    struct smu_i2c_cmd, link);
741 		smu->cmd_i2c_cur = newcmd;
742 		list_del(&cmd->link);
743 
744 		/* Queue with low level smu */
745 		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
746 		if (smu->cmd_cur == NULL)
747 			smu_start_cmd();
748 	}
749 	spin_unlock_irqrestore(&smu->lock, flags);
750 
751 	/* Call command completion handler if any */
752 	if (done)
753 		done(cmd, misc);
754 
755 }
756 
757 
758 static void smu_i2c_retry(unsigned long data)
759 {
760 	struct smu_i2c_cmd	*cmd = smu->cmd_i2c_cur;
761 
762 	DPRINTK("SMU: i2c failure, requeuing...\n");
763 
764 	/* requeue command simply by resetting reply_len */
765 	cmd->pdata[0] = 0xff;
766 	cmd->scmd.reply_len = sizeof(cmd->pdata);
767 	smu_queue_cmd(&cmd->scmd);
768 }
769 
770 
771 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
772 {
773 	struct smu_i2c_cmd	*cmd = misc;
774 	int			fail = 0;
775 
776 	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
777 		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
778 
779 	/* Check for possible status */
780 	if (scmd->status < 0)
781 		fail = 1;
782 	else if (cmd->read) {
783 		if (cmd->stage == 0)
784 			fail = cmd->pdata[0] != 0;
785 		else
786 			fail = cmd->pdata[0] >= 0x80;
787 	} else {
788 		fail = cmd->pdata[0] != 0;
789 	}
790 
791 	/* Handle failures by requeuing command, after 5ms interval
792 	 */
793 	if (fail && --cmd->retries > 0) {
794 		DPRINTK("SMU: i2c failure, starting timer...\n");
795 		BUG_ON(cmd != smu->cmd_i2c_cur);
796 		if (!smu_irq_inited) {
797 			mdelay(5);
798 			smu_i2c_retry(0);
799 			return;
800 		}
801 		mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
802 		return;
803 	}
804 
805 	/* If failure or stage 1, command is complete */
806 	if (fail || cmd->stage != 0) {
807 		smu_i2c_complete_command(cmd, fail);
808 		return;
809 	}
810 
811 	DPRINTK("SMU: going to stage 1\n");
812 
813 	/* Ok, initial command complete, now poll status */
814 	scmd->reply_buf = cmd->pdata;
815 	scmd->reply_len = sizeof(cmd->pdata);
816 	scmd->data_buf = cmd->pdata;
817 	scmd->data_len = 1;
818 	cmd->pdata[0] = 0;
819 	cmd->stage = 1;
820 	cmd->retries = 20;
821 	smu_queue_cmd(scmd);
822 }
823 
824 
825 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
826 {
827 	unsigned long flags;
828 
829 	if (smu == NULL)
830 		return -ENODEV;
831 
832 	/* Fill most fields of scmd */
833 	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
834 	cmd->scmd.done = smu_i2c_low_completion;
835 	cmd->scmd.misc = cmd;
836 	cmd->scmd.reply_buf = cmd->pdata;
837 	cmd->scmd.reply_len = sizeof(cmd->pdata);
838 	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
839 	cmd->scmd.status = 1;
840 	cmd->stage = 0;
841 	cmd->pdata[0] = 0xff;
842 	cmd->retries = 20;
843 	cmd->status = 1;
844 
845 	/* Check transfer type, sanitize some "info" fields
846 	 * based on transfer type and do more checking
847 	 */
848 	cmd->info.caddr = cmd->info.devaddr;
849 	cmd->read = cmd->info.devaddr & 0x01;
850 	switch(cmd->info.type) {
851 	case SMU_I2C_TRANSFER_SIMPLE:
852 		memset(&cmd->info.sublen, 0, 4);
853 		break;
854 	case SMU_I2C_TRANSFER_COMBINED:
855 		cmd->info.devaddr &= 0xfe;
856 	case SMU_I2C_TRANSFER_STDSUB:
857 		if (cmd->info.sublen > 3)
858 			return -EINVAL;
859 		break;
860 	default:
861 		return -EINVAL;
862 	}
863 
864 	/* Finish setting up command based on transfer direction
865 	 */
866 	if (cmd->read) {
867 		if (cmd->info.datalen > SMU_I2C_READ_MAX)
868 			return -EINVAL;
869 		memset(cmd->info.data, 0xff, cmd->info.datalen);
870 		cmd->scmd.data_len = 9;
871 	} else {
872 		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
873 			return -EINVAL;
874 		cmd->scmd.data_len = 9 + cmd->info.datalen;
875 	}
876 
877 	DPRINTK("SMU: i2c enqueuing command\n");
878 	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
879 		cmd->read ? "read" : "write", cmd->info.datalen,
880 		cmd->info.bus, cmd->info.caddr,
881 		cmd->info.subaddr[0], cmd->info.type);
882 
883 
884 	/* Enqueue command in i2c list, and if empty, enqueue also in
885 	 * main command list
886 	 */
887 	spin_lock_irqsave(&smu->lock, flags);
888 	if (smu->cmd_i2c_cur == NULL) {
889 		smu->cmd_i2c_cur = cmd;
890 		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
891 		if (smu->cmd_cur == NULL)
892 			smu_start_cmd();
893 	} else
894 		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
895 	spin_unlock_irqrestore(&smu->lock, flags);
896 
897 	return 0;
898 }
899 
900 /*
901  * Handling of "partitions"
902  */
903 
904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
905 {
906 	DECLARE_COMPLETION_ONSTACK(comp);
907 	unsigned int chunk;
908 	struct smu_cmd cmd;
909 	int rc;
910 	u8 params[8];
911 
912 	/* We currently use a chunk size of 0xe. We could check the
913 	 * SMU firmware version and use bigger sizes though
914 	 */
915 	chunk = 0xe;
916 
917 	while (len) {
918 		unsigned int clen = min(len, chunk);
919 
920 		cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
921 		cmd.data_len = 7;
922 		cmd.data_buf = params;
923 		cmd.reply_len = chunk;
924 		cmd.reply_buf = dest;
925 		cmd.done = smu_done_complete;
926 		cmd.misc = &comp;
927 		params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
928 		params[1] = 0x4;
929 		*((u32 *)&params[2]) = addr;
930 		params[6] = clen;
931 
932 		rc = smu_queue_cmd(&cmd);
933 		if (rc)
934 			return rc;
935 		wait_for_completion(&comp);
936 		if (cmd.status != 0)
937 			return rc;
938 		if (cmd.reply_len != clen) {
939 			printk(KERN_DEBUG "SMU: short read in "
940 			       "smu_read_datablock, got: %d, want: %d\n",
941 			       cmd.reply_len, clen);
942 			return -EIO;
943 		}
944 		len -= clen;
945 		addr += clen;
946 		dest += clen;
947 	}
948 	return 0;
949 }
950 
951 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
952 {
953 	DECLARE_COMPLETION_ONSTACK(comp);
954 	struct smu_simple_cmd cmd;
955 	unsigned int addr, len, tlen;
956 	struct smu_sdbp_header *hdr;
957 	struct property *prop;
958 
959 	/* First query the partition info */
960 	DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
961 	smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
962 			 smu_done_complete, &comp,
963 			 SMU_CMD_PARTITION_LATEST, id);
964 	wait_for_completion(&comp);
965 	DPRINTK("SMU: done, status: %d, reply_len: %d\n",
966 		cmd.cmd.status, cmd.cmd.reply_len);
967 
968 	/* Partition doesn't exist (or other error) */
969 	if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
970 		return NULL;
971 
972 	/* Fetch address and length from reply */
973 	addr = *((u16 *)cmd.buffer);
974 	len = cmd.buffer[3] << 2;
975 	/* Calucluate total length to allocate, including the 17 bytes
976 	 * for "sdb-partition-XX" that we append at the end of the buffer
977 	 */
978 	tlen = sizeof(struct property) + len + 18;
979 
980 	prop = kzalloc(tlen, GFP_KERNEL);
981 	if (prop == NULL)
982 		return NULL;
983 	hdr = (struct smu_sdbp_header *)(prop + 1);
984 	prop->name = ((char *)prop) + tlen - 18;
985 	sprintf(prop->name, "sdb-partition-%02x", id);
986 	prop->length = len;
987 	prop->value = hdr;
988 	prop->next = NULL;
989 
990 	/* Read the datablock */
991 	if (smu_read_datablock((u8 *)hdr, addr, len)) {
992 		printk(KERN_DEBUG "SMU: datablock read failed while reading "
993 		       "partition %02x !\n", id);
994 		goto failure;
995 	}
996 
997 	/* Got it, check a few things and create the property */
998 	if (hdr->id != id) {
999 		printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000 		       "%02x !\n", id, hdr->id);
1001 		goto failure;
1002 	}
1003 	if (of_add_property(smu->of_node, prop)) {
1004 		printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005 		       "property !\n", id);
1006 		goto failure;
1007 	}
1008 
1009 	return hdr;
1010  failure:
1011 	kfree(prop);
1012 	return NULL;
1013 }
1014 
1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016  * when interruptible is 1
1017  */
1018 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019 		unsigned int *size, int interruptible)
1020 {
1021 	char pname[32];
1022 	const struct smu_sdbp_header *part;
1023 
1024 	if (!smu)
1025 		return NULL;
1026 
1027 	sprintf(pname, "sdb-partition-%02x", id);
1028 
1029 	DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030 
1031 	if (interruptible) {
1032 		int rc;
1033 		rc = mutex_lock_interruptible(&smu_part_access);
1034 		if (rc)
1035 			return ERR_PTR(rc);
1036 	} else
1037 		mutex_lock(&smu_part_access);
1038 
1039 	part = of_get_property(smu->of_node, pname, size);
1040 	if (part == NULL) {
1041 		DPRINTK("trying to extract from SMU ...\n");
1042 		part = smu_create_sdb_partition(id);
1043 		if (part != NULL && size)
1044 			*size = part->len << 2;
1045 	}
1046 	mutex_unlock(&smu_part_access);
1047 	return part;
1048 }
1049 
1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051 {
1052 	return __smu_get_sdb_partition(id, size, 0);
1053 }
1054 EXPORT_SYMBOL(smu_get_sdb_partition);
1055 
1056 
1057 /*
1058  * Userland driver interface
1059  */
1060 
1061 
1062 static LIST_HEAD(smu_clist);
1063 static DEFINE_SPINLOCK(smu_clist_lock);
1064 
1065 enum smu_file_mode {
1066 	smu_file_commands,
1067 	smu_file_events,
1068 	smu_file_closing
1069 };
1070 
1071 struct smu_private
1072 {
1073 	struct list_head	list;
1074 	enum smu_file_mode	mode;
1075 	int			busy;
1076 	struct smu_cmd		cmd;
1077 	spinlock_t		lock;
1078 	wait_queue_head_t	wait;
1079 	u8			buffer[SMU_MAX_DATA];
1080 };
1081 
1082 
1083 static int smu_open(struct inode *inode, struct file *file)
1084 {
1085 	struct smu_private *pp;
1086 	unsigned long flags;
1087 
1088 	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089 	if (pp == 0)
1090 		return -ENOMEM;
1091 	spin_lock_init(&pp->lock);
1092 	pp->mode = smu_file_commands;
1093 	init_waitqueue_head(&pp->wait);
1094 
1095 	mutex_lock(&smu_mutex);
1096 	spin_lock_irqsave(&smu_clist_lock, flags);
1097 	list_add(&pp->list, &smu_clist);
1098 	spin_unlock_irqrestore(&smu_clist_lock, flags);
1099 	file->private_data = pp;
1100 	mutex_unlock(&smu_mutex);
1101 
1102 	return 0;
1103 }
1104 
1105 
1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107 {
1108 	struct smu_private *pp = misc;
1109 
1110 	wake_up_all(&pp->wait);
1111 }
1112 
1113 
1114 static ssize_t smu_write(struct file *file, const char __user *buf,
1115 			 size_t count, loff_t *ppos)
1116 {
1117 	struct smu_private *pp = file->private_data;
1118 	unsigned long flags;
1119 	struct smu_user_cmd_hdr hdr;
1120 	int rc = 0;
1121 
1122 	if (pp->busy)
1123 		return -EBUSY;
1124 	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125 		return -EFAULT;
1126 	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127 		pp->mode = smu_file_events;
1128 		return 0;
1129 	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130 		const struct smu_sdbp_header *part;
1131 		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132 		if (part == NULL)
1133 			return -EINVAL;
1134 		else if (IS_ERR(part))
1135 			return PTR_ERR(part);
1136 		return 0;
1137 	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138 		return -EINVAL;
1139 	else if (pp->mode != smu_file_commands)
1140 		return -EBADFD;
1141 	else if (hdr.data_len > SMU_MAX_DATA)
1142 		return -EINVAL;
1143 
1144 	spin_lock_irqsave(&pp->lock, flags);
1145 	if (pp->busy) {
1146 		spin_unlock_irqrestore(&pp->lock, flags);
1147 		return -EBUSY;
1148 	}
1149 	pp->busy = 1;
1150 	pp->cmd.status = 1;
1151 	spin_unlock_irqrestore(&pp->lock, flags);
1152 
1153 	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154 		pp->busy = 0;
1155 		return -EFAULT;
1156 	}
1157 
1158 	pp->cmd.cmd = hdr.cmd;
1159 	pp->cmd.data_len = hdr.data_len;
1160 	pp->cmd.reply_len = SMU_MAX_DATA;
1161 	pp->cmd.data_buf = pp->buffer;
1162 	pp->cmd.reply_buf = pp->buffer;
1163 	pp->cmd.done = smu_user_cmd_done;
1164 	pp->cmd.misc = pp;
1165 	rc = smu_queue_cmd(&pp->cmd);
1166 	if (rc < 0)
1167 		return rc;
1168 	return count;
1169 }
1170 
1171 
1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173 				char __user *buf, size_t count)
1174 {
1175 	DECLARE_WAITQUEUE(wait, current);
1176 	struct smu_user_reply_hdr hdr;
1177 	unsigned long flags;
1178 	int size, rc = 0;
1179 
1180 	if (!pp->busy)
1181 		return 0;
1182 	if (count < sizeof(struct smu_user_reply_hdr))
1183 		return -EOVERFLOW;
1184 	spin_lock_irqsave(&pp->lock, flags);
1185 	if (pp->cmd.status == 1) {
1186 		if (file->f_flags & O_NONBLOCK) {
1187 			spin_unlock_irqrestore(&pp->lock, flags);
1188 			return -EAGAIN;
1189 		}
1190 		add_wait_queue(&pp->wait, &wait);
1191 		for (;;) {
1192 			set_current_state(TASK_INTERRUPTIBLE);
1193 			rc = 0;
1194 			if (pp->cmd.status != 1)
1195 				break;
1196 			rc = -ERESTARTSYS;
1197 			if (signal_pending(current))
1198 				break;
1199 			spin_unlock_irqrestore(&pp->lock, flags);
1200 			schedule();
1201 			spin_lock_irqsave(&pp->lock, flags);
1202 		}
1203 		set_current_state(TASK_RUNNING);
1204 		remove_wait_queue(&pp->wait, &wait);
1205 	}
1206 	spin_unlock_irqrestore(&pp->lock, flags);
1207 	if (rc)
1208 		return rc;
1209 	if (pp->cmd.status != 0)
1210 		pp->cmd.reply_len = 0;
1211 	size = sizeof(hdr) + pp->cmd.reply_len;
1212 	if (count < size)
1213 		size = count;
1214 	rc = size;
1215 	hdr.status = pp->cmd.status;
1216 	hdr.reply_len = pp->cmd.reply_len;
1217 	if (copy_to_user(buf, &hdr, sizeof(hdr)))
1218 		return -EFAULT;
1219 	size -= sizeof(hdr);
1220 	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1221 		return -EFAULT;
1222 	pp->busy = 0;
1223 
1224 	return rc;
1225 }
1226 
1227 
1228 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1229 			       char __user *buf, size_t count)
1230 {
1231 	/* Not implemented */
1232 	msleep_interruptible(1000);
1233 	return 0;
1234 }
1235 
1236 
1237 static ssize_t smu_read(struct file *file, char __user *buf,
1238 			size_t count, loff_t *ppos)
1239 {
1240 	struct smu_private *pp = file->private_data;
1241 
1242 	if (pp->mode == smu_file_commands)
1243 		return smu_read_command(file, pp, buf, count);
1244 	if (pp->mode == smu_file_events)
1245 		return smu_read_events(file, pp, buf, count);
1246 
1247 	return -EBADFD;
1248 }
1249 
1250 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1251 {
1252 	struct smu_private *pp = file->private_data;
1253 	unsigned int mask = 0;
1254 	unsigned long flags;
1255 
1256 	if (pp == 0)
1257 		return 0;
1258 
1259 	if (pp->mode == smu_file_commands) {
1260 		poll_wait(file, &pp->wait, wait);
1261 
1262 		spin_lock_irqsave(&pp->lock, flags);
1263 		if (pp->busy && pp->cmd.status != 1)
1264 			mask |= POLLIN;
1265 		spin_unlock_irqrestore(&pp->lock, flags);
1266 	}
1267 	if (pp->mode == smu_file_events) {
1268 		/* Not yet implemented */
1269 	}
1270 	return mask;
1271 }
1272 
1273 static int smu_release(struct inode *inode, struct file *file)
1274 {
1275 	struct smu_private *pp = file->private_data;
1276 	unsigned long flags;
1277 	unsigned int busy;
1278 
1279 	if (pp == 0)
1280 		return 0;
1281 
1282 	file->private_data = NULL;
1283 
1284 	/* Mark file as closing to avoid races with new request */
1285 	spin_lock_irqsave(&pp->lock, flags);
1286 	pp->mode = smu_file_closing;
1287 	busy = pp->busy;
1288 
1289 	/* Wait for any pending request to complete */
1290 	if (busy && pp->cmd.status == 1) {
1291 		DECLARE_WAITQUEUE(wait, current);
1292 
1293 		add_wait_queue(&pp->wait, &wait);
1294 		for (;;) {
1295 			set_current_state(TASK_UNINTERRUPTIBLE);
1296 			if (pp->cmd.status != 1)
1297 				break;
1298 			spin_unlock_irqrestore(&pp->lock, flags);
1299 			schedule();
1300 			spin_lock_irqsave(&pp->lock, flags);
1301 		}
1302 		set_current_state(TASK_RUNNING);
1303 		remove_wait_queue(&pp->wait, &wait);
1304 	}
1305 	spin_unlock_irqrestore(&pp->lock, flags);
1306 
1307 	spin_lock_irqsave(&smu_clist_lock, flags);
1308 	list_del(&pp->list);
1309 	spin_unlock_irqrestore(&smu_clist_lock, flags);
1310 	kfree(pp);
1311 
1312 	return 0;
1313 }
1314 
1315 
1316 static const struct file_operations smu_device_fops = {
1317 	.llseek		= no_llseek,
1318 	.read		= smu_read,
1319 	.write		= smu_write,
1320 	.poll		= smu_fpoll,
1321 	.open		= smu_open,
1322 	.release	= smu_release,
1323 };
1324 
1325 static struct miscdevice pmu_device = {
1326 	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1327 };
1328 
1329 static int smu_device_init(void)
1330 {
1331 	if (!smu)
1332 		return -ENODEV;
1333 	if (misc_register(&pmu_device) < 0)
1334 		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1335 	return 0;
1336 }
1337 device_initcall(smu_device_init);
1338