smu.c revision 592a607bbc053bc6f614a0e619326009f4b3829e 
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
39#include <asm/byteorder.h>
40#include <asm/io.h>
41#include <asm/prom.h>
42#include <asm/machdep.h>
43#include <asm/pmac_feature.h>
44#include <asm/smu.h>
45#include <asm/sections.h>
46#include <asm/abs_addr.h>
47#include <asm/uaccess.h>
48#include <asm/of_device.h>
49#include <asm/of_platform.h>
50
51#define VERSION "0.7"
52#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
53
54#undef DEBUG_SMU
55
56#ifdef DEBUG_SMU
57#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
58#else
59#define DPRINTK(fmt, args...) do { } while (0)
60#endif
61
62/*
63 * This is the command buffer passed to the SMU hardware
64 */
65#define SMU_MAX_DATA	254
66
67struct smu_cmd_buf {
68	u8 cmd;
69	u8 length;
70	u8 data[SMU_MAX_DATA];
71};
72
73struct smu_device {
74	spinlock_t		lock;
75	struct device_node	*of_node;
76	struct of_device	*of_dev;
77	int			doorbell;	/* doorbell gpio */
78	u32 __iomem		*db_buf;	/* doorbell buffer */
79	struct device_node	*db_node;
80	unsigned int		db_irq;
81	int			msg;
82	struct device_node	*msg_node;
83	unsigned int		msg_irq;
84	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
85	u32			cmd_buf_abs;	/* command buffer absolute */
86	struct list_head	cmd_list;
87	struct smu_cmd		*cmd_cur;	/* pending command */
88	int			broken_nap;
89	struct list_head	cmd_i2c_list;
90	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
91	struct timer_list	i2c_timer;
92};
93
94/*
95 * I don't think there will ever be more than one SMU, so
96 * for now, just hard code that
97 */
98static struct smu_device	*smu;
99static DEFINE_MUTEX(smu_part_access);
100static int smu_irq_inited;
101
102static void smu_i2c_retry(unsigned long data);
103
104/*
105 * SMU driver low level stuff
106 */
107
108static void smu_start_cmd(void)
109{
110	unsigned long faddr, fend;
111	struct smu_cmd *cmd;
112
113	if (list_empty(&smu->cmd_list))
114		return;
115
116	/* Fetch first command in queue */
117	cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
118	smu->cmd_cur = cmd;
119	list_del(&cmd->link);
120
121	DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
122		cmd->data_len);
123	DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
124		((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
125		((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
126		((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
127		((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
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
163static 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
246static 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
265int 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 == NO_IRQ)
284		smu_spinwait_cmd(cmd);
285
286	return 0;
287}
288EXPORT_SYMBOL(smu_queue_cmd);
289
290
291int 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}
319EXPORT_SYMBOL(smu_queue_simple);
320
321
322void 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}
333EXPORT_SYMBOL(smu_poll);
334
335
336void smu_done_complete(struct smu_cmd *cmd, void *misc)
337{
338	struct completion *comp = misc;
339
340	complete(comp);
341}
342EXPORT_SYMBOL(smu_done_complete);
343
344
345void smu_spinwait_cmd(struct smu_cmd *cmd)
346{
347	while(cmd->status == 1)
348		smu_poll();
349}
350EXPORT_SYMBOL(smu_spinwait_cmd);
351
352
353/* RTC low level commands */
354static inline int bcd2hex (int n)
355{
356	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
357}
358
359
360static inline int hex2bcd (int n)
361{
362	return ((n / 10) << 4) + (n % 10);
363}
364
365
366static 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
382int 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
409int 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
434void 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
450void 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
466int smu_present(void)
467{
468	return smu != NULL;
469}
470EXPORT_SYMBOL(smu_present);
471
472
473int __init smu_init (void)
474{
475	struct device_node *np;
476	const u32 *data;
477
478        np = of_find_node_by_type(NULL, "smu");
479        if (np == NULL)
480		return -ENODEV;
481
482	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
483
484	if (smu_cmdbuf_abs == 0) {
485		printk(KERN_ERR "SMU: Command buffer not allocated !\n");
486		return -EINVAL;
487	}
488
489	smu = alloc_bootmem(sizeof(struct smu_device));
490	if (smu == NULL)
491		return -ENOMEM;
492	memset(smu, 0, sizeof(*smu));
493
494	spin_lock_init(&smu->lock);
495	INIT_LIST_HEAD(&smu->cmd_list);
496	INIT_LIST_HEAD(&smu->cmd_i2c_list);
497	smu->of_node = np;
498	smu->db_irq = NO_IRQ;
499	smu->msg_irq = NO_IRQ;
500
501	/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
502	 * 32 bits value safely
503	 */
504	smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
505	smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
506
507	smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
508	if (smu->db_node == NULL) {
509		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
510		goto fail;
511	}
512	data = of_get_property(smu->db_node, "reg", NULL);
513	if (data == NULL) {
514		of_node_put(smu->db_node);
515		smu->db_node = NULL;
516		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
517		goto fail;
518	}
519
520	/* Current setup has one doorbell GPIO that does both doorbell
521	 * and ack. GPIOs are at 0x50, best would be to find that out
522	 * in the device-tree though.
523	 */
524	smu->doorbell = *data;
525	if (smu->doorbell < 0x50)
526		smu->doorbell += 0x50;
527
528	/* Now look for the smu-interrupt GPIO */
529	do {
530		smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
531		if (smu->msg_node == NULL)
532			break;
533		data = of_get_property(smu->msg_node, "reg", NULL);
534		if (data == NULL) {
535			of_node_put(smu->msg_node);
536			smu->msg_node = NULL;
537			break;
538		}
539		smu->msg = *data;
540		if (smu->msg < 0x50)
541			smu->msg += 0x50;
542	} while(0);
543
544	/* Doorbell buffer is currently hard-coded, I didn't find a proper
545	 * device-tree entry giving the address. Best would probably to use
546	 * an offset for K2 base though, but let's do it that way for now.
547	 */
548	smu->db_buf = ioremap(0x8000860c, 0x1000);
549	if (smu->db_buf == NULL) {
550		printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
551		goto fail;
552	}
553
554	/* U3 has an issue with NAP mode when issuing SMU commands */
555	smu->broken_nap = pmac_get_uninorth_variant() < 4;
556	if (smu->broken_nap)
557		printk(KERN_INFO "SMU: using NAP mode workaround\n");
558
559	sys_ctrler = SYS_CTRLER_SMU;
560	return 0;
561
562 fail:
563	smu = NULL;
564	return -ENXIO;
565
566}
567
568
569static int smu_late_init(void)
570{
571	if (!smu)
572		return 0;
573
574	init_timer(&smu->i2c_timer);
575	smu->i2c_timer.function = smu_i2c_retry;
576	smu->i2c_timer.data = (unsigned long)smu;
577
578	if (smu->db_node) {
579		smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
580		if (smu->db_irq == NO_IRQ)
581			printk(KERN_ERR "smu: failed to map irq for node %s\n",
582			       smu->db_node->full_name);
583	}
584	if (smu->msg_node) {
585		smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
586		if (smu->msg_irq == NO_IRQ)
587			printk(KERN_ERR "smu: failed to map irq for node %s\n",
588			       smu->msg_node->full_name);
589	}
590
591	/*
592	 * Try to request the interrupts
593	 */
594
595	if (smu->db_irq != NO_IRQ) {
596		if (request_irq(smu->db_irq, smu_db_intr,
597				IRQF_SHARED, "SMU doorbell", smu) < 0) {
598			printk(KERN_WARNING "SMU: can't "
599			       "request interrupt %d\n",
600			       smu->db_irq);
601			smu->db_irq = NO_IRQ;
602		}
603	}
604
605	if (smu->msg_irq != NO_IRQ) {
606		if (request_irq(smu->msg_irq, smu_msg_intr,
607				IRQF_SHARED, "SMU message", smu) < 0) {
608			printk(KERN_WARNING "SMU: can't "
609			       "request interrupt %d\n",
610			       smu->msg_irq);
611			smu->msg_irq = NO_IRQ;
612		}
613	}
614
615	smu_irq_inited = 1;
616	return 0;
617}
618/* This has to be before arch_initcall as the low i2c stuff relies on the
619 * above having been done before we reach arch_initcalls
620 */
621core_initcall(smu_late_init);
622
623/*
624 * sysfs visibility
625 */
626
627static void smu_expose_childs(struct work_struct *unused)
628{
629	struct device_node *np;
630
631	for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
632		if (of_device_is_compatible(np, "smu-sensors"))
633			of_platform_device_create(np, "smu-sensors",
634						  &smu->of_dev->dev);
635}
636
637static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
638
639static int smu_platform_probe(struct of_device* dev,
640			      const struct of_device_id *match)
641{
642	if (!smu)
643		return -ENODEV;
644	smu->of_dev = dev;
645
646	/*
647	 * Ok, we are matched, now expose all i2c busses. We have to defer
648	 * that unfortunately or it would deadlock inside the device model
649	 */
650	schedule_work(&smu_expose_childs_work);
651
652	return 0;
653}
654
655static struct of_device_id smu_platform_match[] =
656{
657	{
658		.type		= "smu",
659	},
660	{},
661};
662
663static struct of_platform_driver smu_of_platform_driver =
664{
665	.name 		= "smu",
666	.match_table	= smu_platform_match,
667	.probe		= smu_platform_probe,
668};
669
670static int __init smu_init_sysfs(void)
671{
672	/*
673	 * Due to sysfs bogosity, a sysdev is not a real device, so
674	 * we should in fact create both if we want sysdev semantics
675	 * for power management.
676	 * For now, we don't power manage machines with an SMU chip,
677	 * I'm a bit too far from figuring out how that works with those
678	 * new chipsets, but that will come back and bite us
679	 */
680	of_register_platform_driver(&smu_of_platform_driver);
681	return 0;
682}
683
684device_initcall(smu_init_sysfs);
685
686struct of_device *smu_get_ofdev(void)
687{
688	if (!smu)
689		return NULL;
690	return smu->of_dev;
691}
692
693EXPORT_SYMBOL_GPL(smu_get_ofdev);
694
695/*
696 * i2c interface
697 */
698
699static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
700{
701	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
702	void *misc = cmd->misc;
703	unsigned long flags;
704
705	/* Check for read case */
706	if (!fail && cmd->read) {
707		if (cmd->pdata[0] < 1)
708			fail = 1;
709		else
710			memcpy(cmd->info.data, &cmd->pdata[1],
711			       cmd->info.datalen);
712	}
713
714	DPRINTK("SMU: completing, success: %d\n", !fail);
715
716	/* Update status and mark no pending i2c command with lock
717	 * held so nobody comes in while we dequeue an eventual
718	 * pending next i2c command
719	 */
720	spin_lock_irqsave(&smu->lock, flags);
721	smu->cmd_i2c_cur = NULL;
722	wmb();
723	cmd->status = fail ? -EIO : 0;
724
725	/* Is there another i2c command waiting ? */
726	if (!list_empty(&smu->cmd_i2c_list)) {
727		struct smu_i2c_cmd *newcmd;
728
729		/* Fetch it, new current, remove from list */
730		newcmd = list_entry(smu->cmd_i2c_list.next,
731				    struct smu_i2c_cmd, link);
732		smu->cmd_i2c_cur = newcmd;
733		list_del(&cmd->link);
734
735		/* Queue with low level smu */
736		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
737		if (smu->cmd_cur == NULL)
738			smu_start_cmd();
739	}
740	spin_unlock_irqrestore(&smu->lock, flags);
741
742	/* Call command completion handler if any */
743	if (done)
744		done(cmd, misc);
745
746}
747
748
749static void smu_i2c_retry(unsigned long data)
750{
751	struct smu_i2c_cmd	*cmd = smu->cmd_i2c_cur;
752
753	DPRINTK("SMU: i2c failure, requeuing...\n");
754
755	/* requeue command simply by resetting reply_len */
756	cmd->pdata[0] = 0xff;
757	cmd->scmd.reply_len = sizeof(cmd->pdata);
758	smu_queue_cmd(&cmd->scmd);
759}
760
761
762static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
763{
764	struct smu_i2c_cmd	*cmd = misc;
765	int			fail = 0;
766
767	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
768		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
769
770	/* Check for possible status */
771	if (scmd->status < 0)
772		fail = 1;
773	else if (cmd->read) {
774		if (cmd->stage == 0)
775			fail = cmd->pdata[0] != 0;
776		else
777			fail = cmd->pdata[0] >= 0x80;
778	} else {
779		fail = cmd->pdata[0] != 0;
780	}
781
782	/* Handle failures by requeuing command, after 5ms interval
783	 */
784	if (fail && --cmd->retries > 0) {
785		DPRINTK("SMU: i2c failure, starting timer...\n");
786		BUG_ON(cmd != smu->cmd_i2c_cur);
787		if (!smu_irq_inited) {
788			mdelay(5);
789			smu_i2c_retry(0);
790			return;
791		}
792		mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
793		return;
794	}
795
796	/* If failure or stage 1, command is complete */
797	if (fail || cmd->stage != 0) {
798		smu_i2c_complete_command(cmd, fail);
799		return;
800	}
801
802	DPRINTK("SMU: going to stage 1\n");
803
804	/* Ok, initial command complete, now poll status */
805	scmd->reply_buf = cmd->pdata;
806	scmd->reply_len = sizeof(cmd->pdata);
807	scmd->data_buf = cmd->pdata;
808	scmd->data_len = 1;
809	cmd->pdata[0] = 0;
810	cmd->stage = 1;
811	cmd->retries = 20;
812	smu_queue_cmd(scmd);
813}
814
815
816int smu_queue_i2c(struct smu_i2c_cmd *cmd)
817{
818	unsigned long flags;
819
820	if (smu == NULL)
821		return -ENODEV;
822
823	/* Fill most fields of scmd */
824	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
825	cmd->scmd.done = smu_i2c_low_completion;
826	cmd->scmd.misc = cmd;
827	cmd->scmd.reply_buf = cmd->pdata;
828	cmd->scmd.reply_len = sizeof(cmd->pdata);
829	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
830	cmd->scmd.status = 1;
831	cmd->stage = 0;
832	cmd->pdata[0] = 0xff;
833	cmd->retries = 20;
834	cmd->status = 1;
835
836	/* Check transfer type, sanitize some "info" fields
837	 * based on transfer type and do more checking
838	 */
839	cmd->info.caddr = cmd->info.devaddr;
840	cmd->read = cmd->info.devaddr & 0x01;
841	switch(cmd->info.type) {
842	case SMU_I2C_TRANSFER_SIMPLE:
843		memset(&cmd->info.sublen, 0, 4);
844		break;
845	case SMU_I2C_TRANSFER_COMBINED:
846		cmd->info.devaddr &= 0xfe;
847	case SMU_I2C_TRANSFER_STDSUB:
848		if (cmd->info.sublen > 3)
849			return -EINVAL;
850		break;
851	default:
852		return -EINVAL;
853	}
854
855	/* Finish setting up command based on transfer direction
856	 */
857	if (cmd->read) {
858		if (cmd->info.datalen > SMU_I2C_READ_MAX)
859			return -EINVAL;
860		memset(cmd->info.data, 0xff, cmd->info.datalen);
861		cmd->scmd.data_len = 9;
862	} else {
863		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
864			return -EINVAL;
865		cmd->scmd.data_len = 9 + cmd->info.datalen;
866	}
867
868	DPRINTK("SMU: i2c enqueuing command\n");
869	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
870		cmd->read ? "read" : "write", cmd->info.datalen,
871		cmd->info.bus, cmd->info.caddr,
872		cmd->info.subaddr[0], cmd->info.type);
873
874
875	/* Enqueue command in i2c list, and if empty, enqueue also in
876	 * main command list
877	 */
878	spin_lock_irqsave(&smu->lock, flags);
879	if (smu->cmd_i2c_cur == NULL) {
880		smu->cmd_i2c_cur = cmd;
881		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
882		if (smu->cmd_cur == NULL)
883			smu_start_cmd();
884	} else
885		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
886	spin_unlock_irqrestore(&smu->lock, flags);
887
888	return 0;
889}
890
891/*
892 * Handling of "partitions"
893 */
894
895static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
896{
897	DECLARE_COMPLETION_ONSTACK(comp);
898	unsigned int chunk;
899	struct smu_cmd cmd;
900	int rc;
901	u8 params[8];
902
903	/* We currently use a chunk size of 0xe. We could check the
904	 * SMU firmware version and use bigger sizes though
905	 */
906	chunk = 0xe;
907
908	while (len) {
909		unsigned int clen = min(len, chunk);
910
911		cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
912		cmd.data_len = 7;
913		cmd.data_buf = params;
914		cmd.reply_len = chunk;
915		cmd.reply_buf = dest;
916		cmd.done = smu_done_complete;
917		cmd.misc = &comp;
918		params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
919		params[1] = 0x4;
920		*((u32 *)&params[2]) = addr;
921		params[6] = clen;
922
923		rc = smu_queue_cmd(&cmd);
924		if (rc)
925			return rc;
926		wait_for_completion(&comp);
927		if (cmd.status != 0)
928			return rc;
929		if (cmd.reply_len != clen) {
930			printk(KERN_DEBUG "SMU: short read in "
931			       "smu_read_datablock, got: %d, want: %d\n",
932			       cmd.reply_len, clen);
933			return -EIO;
934		}
935		len -= clen;
936		addr += clen;
937		dest += clen;
938	}
939	return 0;
940}
941
942static struct smu_sdbp_header *smu_create_sdb_partition(int id)
943{
944	DECLARE_COMPLETION_ONSTACK(comp);
945	struct smu_simple_cmd cmd;
946	unsigned int addr, len, tlen;
947	struct smu_sdbp_header *hdr;
948	struct property *prop;
949
950	/* First query the partition info */
951	DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
952	smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
953			 smu_done_complete, &comp,
954			 SMU_CMD_PARTITION_LATEST, id);
955	wait_for_completion(&comp);
956	DPRINTK("SMU: done, status: %d, reply_len: %d\n",
957		cmd.cmd.status, cmd.cmd.reply_len);
958
959	/* Partition doesn't exist (or other error) */
960	if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
961		return NULL;
962
963	/* Fetch address and length from reply */
964	addr = *((u16 *)cmd.buffer);
965	len = cmd.buffer[3] << 2;
966	/* Calucluate total length to allocate, including the 17 bytes
967	 * for "sdb-partition-XX" that we append at the end of the buffer
968	 */
969	tlen = sizeof(struct property) + len + 18;
970
971	prop = kzalloc(tlen, GFP_KERNEL);
972	if (prop == NULL)
973		return NULL;
974	hdr = (struct smu_sdbp_header *)(prop + 1);
975	prop->name = ((char *)prop) + tlen - 18;
976	sprintf(prop->name, "sdb-partition-%02x", id);
977	prop->length = len;
978	prop->value = hdr;
979	prop->next = NULL;
980
981	/* Read the datablock */
982	if (smu_read_datablock((u8 *)hdr, addr, len)) {
983		printk(KERN_DEBUG "SMU: datablock read failed while reading "
984		       "partition %02x !\n", id);
985		goto failure;
986	}
987
988	/* Got it, check a few things and create the property */
989	if (hdr->id != id) {
990		printk(KERN_DEBUG "SMU: Reading partition %02x and got "
991		       "%02x !\n", id, hdr->id);
992		goto failure;
993	}
994	if (prom_add_property(smu->of_node, prop)) {
995		printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
996		       "property !\n", id);
997		goto failure;
998	}
999
1000	return hdr;
1001 failure:
1002	kfree(prop);
1003	return NULL;
1004}
1005
1006/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1007 * when interruptible is 1
1008 */
1009const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1010		unsigned int *size, int interruptible)
1011{
1012	char pname[32];
1013	const struct smu_sdbp_header *part;
1014
1015	if (!smu)
1016		return NULL;
1017
1018	sprintf(pname, "sdb-partition-%02x", id);
1019
1020	DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1021
1022	if (interruptible) {
1023		int rc;
1024		rc = mutex_lock_interruptible(&smu_part_access);
1025		if (rc)
1026			return ERR_PTR(rc);
1027	} else
1028		mutex_lock(&smu_part_access);
1029
1030	part = of_get_property(smu->of_node, pname, size);
1031	if (part == NULL) {
1032		DPRINTK("trying to extract from SMU ...\n");
1033		part = smu_create_sdb_partition(id);
1034		if (part != NULL && size)
1035			*size = part->len << 2;
1036	}
1037	mutex_unlock(&smu_part_access);
1038	return part;
1039}
1040
1041const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1042{
1043	return __smu_get_sdb_partition(id, size, 0);
1044}
1045EXPORT_SYMBOL(smu_get_sdb_partition);
1046
1047
1048/*
1049 * Userland driver interface
1050 */
1051
1052
1053static LIST_HEAD(smu_clist);
1054static DEFINE_SPINLOCK(smu_clist_lock);
1055
1056enum smu_file_mode {
1057	smu_file_commands,
1058	smu_file_events,
1059	smu_file_closing
1060};
1061
1062struct smu_private
1063{
1064	struct list_head	list;
1065	enum smu_file_mode	mode;
1066	int			busy;
1067	struct smu_cmd		cmd;
1068	spinlock_t		lock;
1069	wait_queue_head_t	wait;
1070	u8			buffer[SMU_MAX_DATA];
1071};
1072
1073
1074static int smu_open(struct inode *inode, struct file *file)
1075{
1076	struct smu_private *pp;
1077	unsigned long flags;
1078
1079	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1080	if (pp == 0)
1081		return -ENOMEM;
1082	spin_lock_init(&pp->lock);
1083	pp->mode = smu_file_commands;
1084	init_waitqueue_head(&pp->wait);
1085
1086	spin_lock_irqsave(&smu_clist_lock, flags);
1087	list_add(&pp->list, &smu_clist);
1088	spin_unlock_irqrestore(&smu_clist_lock, flags);
1089	file->private_data = pp;
1090
1091	return 0;
1092}
1093
1094
1095static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1096{
1097	struct smu_private *pp = misc;
1098
1099	wake_up_all(&pp->wait);
1100}
1101
1102
1103static ssize_t smu_write(struct file *file, const char __user *buf,
1104			 size_t count, loff_t *ppos)
1105{
1106	struct smu_private *pp = file->private_data;
1107	unsigned long flags;
1108	struct smu_user_cmd_hdr hdr;
1109	int rc = 0;
1110
1111	if (pp->busy)
1112		return -EBUSY;
1113	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1114		return -EFAULT;
1115	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1116		pp->mode = smu_file_events;
1117		return 0;
1118	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1119		const struct smu_sdbp_header *part;
1120		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1121		if (part == NULL)
1122			return -EINVAL;
1123		else if (IS_ERR(part))
1124			return PTR_ERR(part);
1125		return 0;
1126	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1127		return -EINVAL;
1128	else if (pp->mode != smu_file_commands)
1129		return -EBADFD;
1130	else if (hdr.data_len > SMU_MAX_DATA)
1131		return -EINVAL;
1132
1133	spin_lock_irqsave(&pp->lock, flags);
1134	if (pp->busy) {
1135		spin_unlock_irqrestore(&pp->lock, flags);
1136		return -EBUSY;
1137	}
1138	pp->busy = 1;
1139	pp->cmd.status = 1;
1140	spin_unlock_irqrestore(&pp->lock, flags);
1141
1142	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1143		pp->busy = 0;
1144		return -EFAULT;
1145	}
1146
1147	pp->cmd.cmd = hdr.cmd;
1148	pp->cmd.data_len = hdr.data_len;
1149	pp->cmd.reply_len = SMU_MAX_DATA;
1150	pp->cmd.data_buf = pp->buffer;
1151	pp->cmd.reply_buf = pp->buffer;
1152	pp->cmd.done = smu_user_cmd_done;
1153	pp->cmd.misc = pp;
1154	rc = smu_queue_cmd(&pp->cmd);
1155	if (rc < 0)
1156		return rc;
1157	return count;
1158}
1159
1160
1161static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1162				char __user *buf, size_t count)
1163{
1164	DECLARE_WAITQUEUE(wait, current);
1165	struct smu_user_reply_hdr hdr;
1166	unsigned long flags;
1167	int size, rc = 0;
1168
1169	if (!pp->busy)
1170		return 0;
1171	if (count < sizeof(struct smu_user_reply_hdr))
1172		return -EOVERFLOW;
1173	spin_lock_irqsave(&pp->lock, flags);
1174	if (pp->cmd.status == 1) {
1175		if (file->f_flags & O_NONBLOCK)
1176			return -EAGAIN;
1177		add_wait_queue(&pp->wait, &wait);
1178		for (;;) {
1179			set_current_state(TASK_INTERRUPTIBLE);
1180			rc = 0;
1181			if (pp->cmd.status != 1)
1182				break;
1183			rc = -ERESTARTSYS;
1184			if (signal_pending(current))
1185				break;
1186			spin_unlock_irqrestore(&pp->lock, flags);
1187			schedule();
1188			spin_lock_irqsave(&pp->lock, flags);
1189		}
1190		set_current_state(TASK_RUNNING);
1191		remove_wait_queue(&pp->wait, &wait);
1192	}
1193	spin_unlock_irqrestore(&pp->lock, flags);
1194	if (rc)
1195		return rc;
1196	if (pp->cmd.status != 0)
1197		pp->cmd.reply_len = 0;
1198	size = sizeof(hdr) + pp->cmd.reply_len;
1199	if (count < size)
1200		size = count;
1201	rc = size;
1202	hdr.status = pp->cmd.status;
1203	hdr.reply_len = pp->cmd.reply_len;
1204	if (copy_to_user(buf, &hdr, sizeof(hdr)))
1205		return -EFAULT;
1206	size -= sizeof(hdr);
1207	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1208		return -EFAULT;
1209	pp->busy = 0;
1210
1211	return rc;
1212}
1213
1214
1215static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1216			       char __user *buf, size_t count)
1217{
1218	/* Not implemented */
1219	msleep_interruptible(1000);
1220	return 0;
1221}
1222
1223
1224static ssize_t smu_read(struct file *file, char __user *buf,
1225			size_t count, loff_t *ppos)
1226{
1227	struct smu_private *pp = file->private_data;
1228
1229	if (pp->mode == smu_file_commands)
1230		return smu_read_command(file, pp, buf, count);
1231	if (pp->mode == smu_file_events)
1232		return smu_read_events(file, pp, buf, count);
1233
1234	return -EBADFD;
1235}
1236
1237static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1238{
1239	struct smu_private *pp = file->private_data;
1240	unsigned int mask = 0;
1241	unsigned long flags;
1242
1243	if (pp == 0)
1244		return 0;
1245
1246	if (pp->mode == smu_file_commands) {
1247		poll_wait(file, &pp->wait, wait);
1248
1249		spin_lock_irqsave(&pp->lock, flags);
1250		if (pp->busy && pp->cmd.status != 1)
1251			mask |= POLLIN;
1252		spin_unlock_irqrestore(&pp->lock, flags);
1253	} if (pp->mode == smu_file_events) {
1254		/* Not yet implemented */
1255	}
1256	return mask;
1257}
1258
1259static int smu_release(struct inode *inode, struct file *file)
1260{
1261	struct smu_private *pp = file->private_data;
1262	unsigned long flags;
1263	unsigned int busy;
1264
1265	if (pp == 0)
1266		return 0;
1267
1268	file->private_data = NULL;
1269
1270	/* Mark file as closing to avoid races with new request */
1271	spin_lock_irqsave(&pp->lock, flags);
1272	pp->mode = smu_file_closing;
1273	busy = pp->busy;
1274
1275	/* Wait for any pending request to complete */
1276	if (busy && pp->cmd.status == 1) {
1277		DECLARE_WAITQUEUE(wait, current);
1278
1279		add_wait_queue(&pp->wait, &wait);
1280		for (;;) {
1281			set_current_state(TASK_UNINTERRUPTIBLE);
1282			if (pp->cmd.status != 1)
1283				break;
1284			spin_unlock_irqrestore(&pp->lock, flags);
1285			schedule();
1286			spin_lock_irqsave(&pp->lock, flags);
1287		}
1288		set_current_state(TASK_RUNNING);
1289		remove_wait_queue(&pp->wait, &wait);
1290	}
1291	spin_unlock_irqrestore(&pp->lock, flags);
1292
1293	spin_lock_irqsave(&smu_clist_lock, flags);
1294	list_del(&pp->list);
1295	spin_unlock_irqrestore(&smu_clist_lock, flags);
1296	kfree(pp);
1297
1298	return 0;
1299}
1300
1301
1302static const struct file_operations smu_device_fops = {
1303	.llseek		= no_llseek,
1304	.read		= smu_read,
1305	.write		= smu_write,
1306	.poll		= smu_fpoll,
1307	.open		= smu_open,
1308	.release	= smu_release,
1309};
1310
1311static struct miscdevice pmu_device = {
1312	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1313};
1314
1315static int smu_device_init(void)
1316{
1317	if (!smu)
1318		return -ENODEV;
1319	if (misc_register(&pmu_device) < 0)
1320		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1321	return 0;
1322}
1323device_initcall(smu_device_init);
1324