1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * PowerMac G5 SMU driver
4  *
5  * Copyright 2004 J. Mayer <l_indien@magic.fr>
6  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
7  */
8 
9 /*
10  * TODO:
11  *  - maybe add timeout to commands ?
12  *  - blocking version of time functions
13  *  - polling version of i2c commands (including timer that works with
14  *    interrupts off)
15  *  - maybe avoid some data copies with i2c by directly using the smu cmd
16  *    buffer and a lower level internal interface
17  *  - understand SMU -> CPU events and implement reception of them via
18  *    the userland interface
19  */
20 
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/device.h>
24 #include <linux/dmapool.h>
25 #include <linux/memblock.h>
26 #include <linux/vmalloc.h>
27 #include <linux/highmem.h>
28 #include <linux/jiffies.h>
29 #include <linux/interrupt.h>
30 #include <linux/rtc.h>
31 #include <linux/completion.h>
32 #include <linux/miscdevice.h>
33 #include <linux/delay.h>
34 #include <linux/poll.h>
35 #include <linux/mutex.h>
36 #include <linux/of_device.h>
37 #include <linux/of_irq.h>
38 #include <linux/of_platform.h>
39 #include <linux/slab.h>
40 #include <linux/sched/signal.h>
41 
42 #include <asm/byteorder.h>
43 #include <asm/io.h>
44 #include <asm/machdep.h>
45 #include <asm/pmac_feature.h>
46 #include <asm/smu.h>
47 #include <asm/sections.h>
48 #include <linux/uaccess.h>
49 
50 #define VERSION "0.7"
51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
52 
53 #undef DEBUG_SMU
54 
55 #ifdef DEBUG_SMU
56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
57 #else
58 #define DPRINTK(fmt, args...) do { } while (0)
59 #endif
60 
61 /*
62  * This is the command buffer passed to the SMU hardware
63  */
64 #define SMU_MAX_DATA	254
65 
66 struct smu_cmd_buf {
67 	u8 cmd;
68 	u8 length;
69 	u8 data[SMU_MAX_DATA];
70 };
71 
72 struct smu_device {
73 	spinlock_t		lock;
74 	struct device_node	*of_node;
75 	struct platform_device	*of_dev;
76 	int			doorbell;	/* doorbell gpio */
77 	u32 __iomem		*db_buf;	/* doorbell buffer */
78 	struct device_node	*db_node;
79 	unsigned int		db_irq;
80 	int			msg;
81 	struct device_node	*msg_node;
82 	unsigned int		msg_irq;
83 	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
84 	u32			cmd_buf_abs;	/* command buffer absolute */
85 	struct list_head	cmd_list;
86 	struct smu_cmd		*cmd_cur;	/* pending command */
87 	int			broken_nap;
88 	struct list_head	cmd_i2c_list;
89 	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
90 	struct timer_list	i2c_timer;
91 };
92 
93 /*
94  * I don't think there will ever be more than one SMU, so
95  * for now, just hard code that
96  */
97 static DEFINE_MUTEX(smu_mutex);
98 static struct smu_device	*smu;
99 static DEFINE_MUTEX(smu_part_access);
100 static int smu_irq_inited;
101 static unsigned long smu_cmdbuf_abs;
102 
103 static void smu_i2c_retry(struct timer_list *t);
104 
105 /*
106  * SMU driver low level stuff
107  */
108 
smu_start_cmd(void)109 static void smu_start_cmd(void)
110 {
111 	unsigned long faddr, fend;
112 	struct smu_cmd *cmd;
113 
114 	if (list_empty(&smu->cmd_list))
115 		return;
116 
117 	/* Fetch first command in queue */
118 	cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
119 	smu->cmd_cur = cmd;
120 	list_del(&cmd->link);
121 
122 	DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
123 		cmd->data_len);
124 	DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
125 
126 	/* Fill the SMU command buffer */
127 	smu->cmd_buf->cmd = cmd->cmd;
128 	smu->cmd_buf->length = cmd->data_len;
129 	memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
130 
131 	/* Flush command and data to RAM */
132 	faddr = (unsigned long)smu->cmd_buf;
133 	fend = faddr + smu->cmd_buf->length + 2;
134 	flush_dcache_range(faddr, fend);
135 
136 
137 	/* We also disable NAP mode for the duration of the command
138 	 * on U3 based machines.
139 	 * This is slightly racy as it can be written back to 1 by a sysctl
140 	 * but that never happens in practice. There seem to be an issue with
141 	 * U3 based machines such as the iMac G5 where napping for the
142 	 * whole duration of the command prevents the SMU from fetching it
143 	 * from memory. This might be related to the strange i2c based
144 	 * mechanism the SMU uses to access memory.
145 	 */
146 	if (smu->broken_nap)
147 		powersave_nap = 0;
148 
149 	/* This isn't exactly a DMA mapping here, I suspect
150 	 * the SMU is actually communicating with us via i2c to the
151 	 * northbridge or the CPU to access RAM.
152 	 */
153 	writel(smu->cmd_buf_abs, smu->db_buf);
154 
155 	/* Ring the SMU doorbell */
156 	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
157 }
158 
159 
smu_db_intr(int irq,void * arg)160 static irqreturn_t smu_db_intr(int irq, void *arg)
161 {
162 	unsigned long flags;
163 	struct smu_cmd *cmd;
164 	void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
165 	void *misc = NULL;
166 	u8 gpio;
167 	int rc = 0;
168 
169 	/* SMU completed the command, well, we hope, let's make sure
170 	 * of it
171 	 */
172 	spin_lock_irqsave(&smu->lock, flags);
173 
174 	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
175 	if ((gpio & 7) != 7) {
176 		spin_unlock_irqrestore(&smu->lock, flags);
177 		return IRQ_HANDLED;
178 	}
179 
180 	cmd = smu->cmd_cur;
181 	smu->cmd_cur = NULL;
182 	if (cmd == NULL)
183 		goto bail;
184 
185 	if (rc == 0) {
186 		unsigned long faddr;
187 		int reply_len;
188 		u8 ack;
189 
190 		/* CPU might have brought back the cache line, so we need
191 		 * to flush again before peeking at the SMU response. We
192 		 * flush the entire buffer for now as we haven't read the
193 		 * reply length (it's only 2 cache lines anyway)
194 		 */
195 		faddr = (unsigned long)smu->cmd_buf;
196 		flush_dcache_range(faddr, faddr + 256);
197 
198 		/* Now check ack */
199 		ack = (~cmd->cmd) & 0xff;
200 		if (ack != smu->cmd_buf->cmd) {
201 			DPRINTK("SMU: incorrect ack, want %x got %x\n",
202 				ack, smu->cmd_buf->cmd);
203 			rc = -EIO;
204 		}
205 		reply_len = rc == 0 ? smu->cmd_buf->length : 0;
206 		DPRINTK("SMU: reply len: %d\n", reply_len);
207 		if (reply_len > cmd->reply_len) {
208 			printk(KERN_WARNING "SMU: reply buffer too small,"
209 			       "got %d bytes for a %d bytes buffer\n",
210 			       reply_len, cmd->reply_len);
211 			reply_len = cmd->reply_len;
212 		}
213 		cmd->reply_len = reply_len;
214 		if (cmd->reply_buf && reply_len)
215 			memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
216 	}
217 
218 	/* Now complete the command. Write status last in order as we lost
219 	 * ownership of the command structure as soon as it's no longer -1
220 	 */
221 	done = cmd->done;
222 	misc = cmd->misc;
223 	mb();
224 	cmd->status = rc;
225 
226 	/* Re-enable NAP mode */
227 	if (smu->broken_nap)
228 		powersave_nap = 1;
229  bail:
230 	/* Start next command if any */
231 	smu_start_cmd();
232 	spin_unlock_irqrestore(&smu->lock, flags);
233 
234 	/* Call command completion handler if any */
235 	if (done)
236 		done(cmd, misc);
237 
238 	/* It's an edge interrupt, nothing to do */
239 	return IRQ_HANDLED;
240 }
241 
242 
smu_msg_intr(int irq,void * arg)243 static irqreturn_t smu_msg_intr(int irq, void *arg)
244 {
245 	/* I don't quite know what to do with this one, we seem to never
246 	 * receive it, so I suspect we have to arm it someway in the SMU
247 	 * to start getting events that way.
248 	 */
249 
250 	printk(KERN_INFO "SMU: message interrupt !\n");
251 
252 	/* It's an edge interrupt, nothing to do */
253 	return IRQ_HANDLED;
254 }
255 
256 
257 /*
258  * Queued command management.
259  *
260  */
261 
smu_queue_cmd(struct smu_cmd * cmd)262 int smu_queue_cmd(struct smu_cmd *cmd)
263 {
264 	unsigned long flags;
265 
266 	if (smu == NULL)
267 		return -ENODEV;
268 	if (cmd->data_len > SMU_MAX_DATA ||
269 	    cmd->reply_len > SMU_MAX_DATA)
270 		return -EINVAL;
271 
272 	cmd->status = 1;
273 	spin_lock_irqsave(&smu->lock, flags);
274 	list_add_tail(&cmd->link, &smu->cmd_list);
275 	if (smu->cmd_cur == NULL)
276 		smu_start_cmd();
277 	spin_unlock_irqrestore(&smu->lock, flags);
278 
279 	/* Workaround for early calls when irq isn't available */
280 	if (!smu_irq_inited || !smu->db_irq)
281 		smu_spinwait_cmd(cmd);
282 
283 	return 0;
284 }
285 EXPORT_SYMBOL(smu_queue_cmd);
286 
287 
smu_queue_simple(struct smu_simple_cmd * scmd,u8 command,unsigned int data_len,void (* done)(struct smu_cmd * cmd,void * misc),void * misc,...)288 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
289 		     unsigned int data_len,
290 		     void (*done)(struct smu_cmd *cmd, void *misc),
291 		     void *misc, ...)
292 {
293 	struct smu_cmd *cmd = &scmd->cmd;
294 	va_list list;
295 	int i;
296 
297 	if (data_len > sizeof(scmd->buffer))
298 		return -EINVAL;
299 
300 	memset(scmd, 0, sizeof(*scmd));
301 	cmd->cmd = command;
302 	cmd->data_len = data_len;
303 	cmd->data_buf = scmd->buffer;
304 	cmd->reply_len = sizeof(scmd->buffer);
305 	cmd->reply_buf = scmd->buffer;
306 	cmd->done = done;
307 	cmd->misc = misc;
308 
309 	va_start(list, misc);
310 	for (i = 0; i < data_len; ++i)
311 		scmd->buffer[i] = (u8)va_arg(list, int);
312 	va_end(list);
313 
314 	return smu_queue_cmd(cmd);
315 }
316 EXPORT_SYMBOL(smu_queue_simple);
317 
318 
smu_poll(void)319 void smu_poll(void)
320 {
321 	u8 gpio;
322 
323 	if (smu == NULL)
324 		return;
325 
326 	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
327 	if ((gpio & 7) == 7)
328 		smu_db_intr(smu->db_irq, smu);
329 }
330 EXPORT_SYMBOL(smu_poll);
331 
332 
smu_done_complete(struct smu_cmd * cmd,void * misc)333 void smu_done_complete(struct smu_cmd *cmd, void *misc)
334 {
335 	struct completion *comp = misc;
336 
337 	complete(comp);
338 }
339 EXPORT_SYMBOL(smu_done_complete);
340 
341 
smu_spinwait_cmd(struct smu_cmd * cmd)342 void smu_spinwait_cmd(struct smu_cmd *cmd)
343 {
344 	while(cmd->status == 1)
345 		smu_poll();
346 }
347 EXPORT_SYMBOL(smu_spinwait_cmd);
348 
349 
350 /* RTC low level commands */
bcd2hex(int n)351 static inline int bcd2hex (int n)
352 {
353 	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
354 }
355 
356 
hex2bcd(int n)357 static inline int hex2bcd (int n)
358 {
359 	return ((n / 10) << 4) + (n % 10);
360 }
361 
362 
smu_fill_set_rtc_cmd(struct smu_cmd_buf * cmd_buf,struct rtc_time * time)363 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
364 					struct rtc_time *time)
365 {
366 	cmd_buf->cmd = 0x8e;
367 	cmd_buf->length = 8;
368 	cmd_buf->data[0] = 0x80;
369 	cmd_buf->data[1] = hex2bcd(time->tm_sec);
370 	cmd_buf->data[2] = hex2bcd(time->tm_min);
371 	cmd_buf->data[3] = hex2bcd(time->tm_hour);
372 	cmd_buf->data[4] = time->tm_wday;
373 	cmd_buf->data[5] = hex2bcd(time->tm_mday);
374 	cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
375 	cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
376 }
377 
378 
smu_get_rtc_time(struct rtc_time * time,int spinwait)379 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
380 {
381 	struct smu_simple_cmd cmd;
382 	int rc;
383 
384 	if (smu == NULL)
385 		return -ENODEV;
386 
387 	memset(time, 0, sizeof(struct rtc_time));
388 	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
389 			      SMU_CMD_RTC_GET_DATETIME);
390 	if (rc)
391 		return rc;
392 	smu_spinwait_simple(&cmd);
393 
394 	time->tm_sec = bcd2hex(cmd.buffer[0]);
395 	time->tm_min = bcd2hex(cmd.buffer[1]);
396 	time->tm_hour = bcd2hex(cmd.buffer[2]);
397 	time->tm_wday = bcd2hex(cmd.buffer[3]);
398 	time->tm_mday = bcd2hex(cmd.buffer[4]);
399 	time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
400 	time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
401 
402 	return 0;
403 }
404 
405 
smu_set_rtc_time(struct rtc_time * time,int spinwait)406 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
407 {
408 	struct smu_simple_cmd cmd;
409 	int rc;
410 
411 	if (smu == NULL)
412 		return -ENODEV;
413 
414 	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
415 			      SMU_CMD_RTC_SET_DATETIME,
416 			      hex2bcd(time->tm_sec),
417 			      hex2bcd(time->tm_min),
418 			      hex2bcd(time->tm_hour),
419 			      time->tm_wday,
420 			      hex2bcd(time->tm_mday),
421 			      hex2bcd(time->tm_mon) + 1,
422 			      hex2bcd(time->tm_year - 100));
423 	if (rc)
424 		return rc;
425 	smu_spinwait_simple(&cmd);
426 
427 	return 0;
428 }
429 
430 
smu_shutdown(void)431 void smu_shutdown(void)
432 {
433 	struct smu_simple_cmd cmd;
434 
435 	if (smu == NULL)
436 		return;
437 
438 	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
439 			     'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
440 		return;
441 	smu_spinwait_simple(&cmd);
442 	for (;;)
443 		;
444 }
445 
446 
smu_restart(void)447 void smu_restart(void)
448 {
449 	struct smu_simple_cmd cmd;
450 
451 	if (smu == NULL)
452 		return;
453 
454 	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
455 			     'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
456 		return;
457 	smu_spinwait_simple(&cmd);
458 	for (;;)
459 		;
460 }
461 
462 
smu_present(void)463 int smu_present(void)
464 {
465 	return smu != NULL;
466 }
467 EXPORT_SYMBOL(smu_present);
468 
469 
smu_init(void)470 int __init smu_init (void)
471 {
472 	struct device_node *np;
473 	const u32 *data;
474 	int ret = 0;
475 
476         np = of_find_node_by_type(NULL, "smu");
477         if (np == NULL)
478 		return -ENODEV;
479 
480 	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
481 
482 	/*
483 	 * SMU based G5s need some memory below 2Gb. Thankfully this is
484 	 * called at a time where memblock is still available.
485 	 */
486 	smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL);
487 	if (smu_cmdbuf_abs == 0) {
488 		printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
489 		ret = -EINVAL;
490 		goto fail_np;
491 	}
492 
493 	smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
494 	if (!smu)
495 		panic("%s: Failed to allocate %zu bytes\n", __func__,
496 		      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 	memblock_free(smu, sizeof(struct smu_device));
573 	smu = NULL;
574 fail_np:
575 	of_node_put(np);
576 	return ret;
577 }
578 
579 
smu_late_init(void)580 static int smu_late_init(void)
581 {
582 	if (!smu)
583 		return 0;
584 
585 	timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
586 
587 	if (smu->db_node) {
588 		smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
589 		if (!smu->db_irq)
590 			printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
591 			       smu->db_node);
592 	}
593 	if (smu->msg_node) {
594 		smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
595 		if (!smu->msg_irq)
596 			printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
597 			       smu->msg_node);
598 	}
599 
600 	/*
601 	 * Try to request the interrupts
602 	 */
603 
604 	if (smu->db_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 = 0;
611 		}
612 	}
613 
614 	if (smu->msg_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 = 0;
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_each_child_of_node(smu->of_node, np)
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 		.of_match_table = smu_platform_match,
676 	},
677 	.probe		= smu_platform_probe,
678 };
679 
smu_init_sysfs(void)680 static int __init smu_init_sysfs(void)
681 {
682 	/*
683 	 * For now, we don't power manage machines with an SMU chip,
684 	 * I'm a bit too far from figuring out how that works with those
685 	 * new chipsets, but that will come back and bite us
686 	 */
687 	platform_driver_register(&smu_of_platform_driver);
688 	return 0;
689 }
690 
691 device_initcall(smu_init_sysfs);
692 
smu_get_ofdev(void)693 struct platform_device *smu_get_ofdev(void)
694 {
695 	if (!smu)
696 		return NULL;
697 	return smu->of_dev;
698 }
699 
700 EXPORT_SYMBOL_GPL(smu_get_ofdev);
701 
702 /*
703  * i2c interface
704  */
705 
smu_i2c_complete_command(struct smu_i2c_cmd * cmd,int fail)706 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
707 {
708 	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
709 	void *misc = cmd->misc;
710 	unsigned long flags;
711 
712 	/* Check for read case */
713 	if (!fail && cmd->read) {
714 		if (cmd->pdata[0] < 1)
715 			fail = 1;
716 		else
717 			memcpy(cmd->info.data, &cmd->pdata[1],
718 			       cmd->info.datalen);
719 	}
720 
721 	DPRINTK("SMU: completing, success: %d\n", !fail);
722 
723 	/* Update status and mark no pending i2c command with lock
724 	 * held so nobody comes in while we dequeue an eventual
725 	 * pending next i2c command
726 	 */
727 	spin_lock_irqsave(&smu->lock, flags);
728 	smu->cmd_i2c_cur = NULL;
729 	wmb();
730 	cmd->status = fail ? -EIO : 0;
731 
732 	/* Is there another i2c command waiting ? */
733 	if (!list_empty(&smu->cmd_i2c_list)) {
734 		struct smu_i2c_cmd *newcmd;
735 
736 		/* Fetch it, new current, remove from list */
737 		newcmd = list_entry(smu->cmd_i2c_list.next,
738 				    struct smu_i2c_cmd, link);
739 		smu->cmd_i2c_cur = newcmd;
740 		list_del(&cmd->link);
741 
742 		/* Queue with low level smu */
743 		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
744 		if (smu->cmd_cur == NULL)
745 			smu_start_cmd();
746 	}
747 	spin_unlock_irqrestore(&smu->lock, flags);
748 
749 	/* Call command completion handler if any */
750 	if (done)
751 		done(cmd, misc);
752 
753 }
754 
755 
smu_i2c_retry(struct timer_list * unused)756 static void smu_i2c_retry(struct timer_list *unused)
757 {
758 	struct smu_i2c_cmd	*cmd = smu->cmd_i2c_cur;
759 
760 	DPRINTK("SMU: i2c failure, requeuing...\n");
761 
762 	/* requeue command simply by resetting reply_len */
763 	cmd->pdata[0] = 0xff;
764 	cmd->scmd.reply_len = sizeof(cmd->pdata);
765 	smu_queue_cmd(&cmd->scmd);
766 }
767 
768 
smu_i2c_low_completion(struct smu_cmd * scmd,void * misc)769 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
770 {
771 	struct smu_i2c_cmd	*cmd = misc;
772 	int			fail = 0;
773 
774 	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
775 		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
776 
777 	/* Check for possible status */
778 	if (scmd->status < 0)
779 		fail = 1;
780 	else if (cmd->read) {
781 		if (cmd->stage == 0)
782 			fail = cmd->pdata[0] != 0;
783 		else
784 			fail = cmd->pdata[0] >= 0x80;
785 	} else {
786 		fail = cmd->pdata[0] != 0;
787 	}
788 
789 	/* Handle failures by requeuing command, after 5ms interval
790 	 */
791 	if (fail && --cmd->retries > 0) {
792 		DPRINTK("SMU: i2c failure, starting timer...\n");
793 		BUG_ON(cmd != smu->cmd_i2c_cur);
794 		if (!smu_irq_inited) {
795 			mdelay(5);
796 			smu_i2c_retry(NULL);
797 			return;
798 		}
799 		mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
800 		return;
801 	}
802 
803 	/* If failure or stage 1, command is complete */
804 	if (fail || cmd->stage != 0) {
805 		smu_i2c_complete_command(cmd, fail);
806 		return;
807 	}
808 
809 	DPRINTK("SMU: going to stage 1\n");
810 
811 	/* Ok, initial command complete, now poll status */
812 	scmd->reply_buf = cmd->pdata;
813 	scmd->reply_len = sizeof(cmd->pdata);
814 	scmd->data_buf = cmd->pdata;
815 	scmd->data_len = 1;
816 	cmd->pdata[0] = 0;
817 	cmd->stage = 1;
818 	cmd->retries = 20;
819 	smu_queue_cmd(scmd);
820 }
821 
822 
smu_queue_i2c(struct smu_i2c_cmd * cmd)823 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
824 {
825 	unsigned long flags;
826 
827 	if (smu == NULL)
828 		return -ENODEV;
829 
830 	/* Fill most fields of scmd */
831 	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
832 	cmd->scmd.done = smu_i2c_low_completion;
833 	cmd->scmd.misc = cmd;
834 	cmd->scmd.reply_buf = cmd->pdata;
835 	cmd->scmd.reply_len = sizeof(cmd->pdata);
836 	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
837 	cmd->scmd.status = 1;
838 	cmd->stage = 0;
839 	cmd->pdata[0] = 0xff;
840 	cmd->retries = 20;
841 	cmd->status = 1;
842 
843 	/* Check transfer type, sanitize some "info" fields
844 	 * based on transfer type and do more checking
845 	 */
846 	cmd->info.caddr = cmd->info.devaddr;
847 	cmd->read = cmd->info.devaddr & 0x01;
848 	switch(cmd->info.type) {
849 	case SMU_I2C_TRANSFER_SIMPLE:
850 		cmd->info.sublen = 0;
851 		memset(cmd->info.subaddr, 0, sizeof(cmd->info.subaddr));
852 		break;
853 	case SMU_I2C_TRANSFER_COMBINED:
854 		cmd->info.devaddr &= 0xfe;
855 		fallthrough;
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 
smu_read_datablock(u8 * dest,unsigned int addr,unsigned int len)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 
smu_create_sdb_partition(int id)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  */
__smu_get_sdb_partition(int id,unsigned int * size,int interruptible)1018 static 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 
smu_get_sdb_partition(int id,unsigned int * size)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 
smu_open(struct inode * inode,struct file * file)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)
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 
smu_user_cmd_done(struct smu_cmd * cmd,void * misc)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 
smu_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)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 
smu_read_command(struct file * file,struct smu_private * pp,char __user * buf,size_t count)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 
smu_read_events(struct file * file,struct smu_private * pp,char __user * buf,size_t count)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 
smu_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)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 
smu_fpoll(struct file * file,poll_table * wait)1250 static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1251 {
1252 	struct smu_private *pp = file->private_data;
1253 	__poll_t mask = 0;
1254 	unsigned long flags;
1255 
1256 	if (!pp)
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 |= EPOLLIN;
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 
smu_release(struct inode * inode,struct file * file)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)
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 
smu_device_init(void)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