1 /*
2  * ImgTec IR Hardware Decoder found in PowerDown Controller.
3  *
4  * Copyright 2010-2014 Imagination Technologies Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2 of the License, or (at your
9  * option) any later version.
10  *
11  * This ties into the input subsystem using the RC-core. Protocol support is
12  * provided in separate modules which provide the parameters and scancode
13  * translation functions to set up the hardware decoder and interpret the
14  * resulting input.
15  */
16 
17 #include <linux/bitops.h>
18 #include <linux/clk.h>
19 #include <linux/interrupt.h>
20 #include <linux/spinlock.h>
21 #include <linux/timer.h>
22 #include <media/rc-core.h>
23 #include "img-ir.h"
24 
25 /* Decoders lock (only modified to preprocess them) */
26 static DEFINE_SPINLOCK(img_ir_decoders_lock);
27 
28 static bool img_ir_decoders_preprocessed;
29 static struct img_ir_decoder *img_ir_decoders[] = {
30 #ifdef CONFIG_IR_IMG_NEC
31 	&img_ir_nec,
32 #endif
33 #ifdef CONFIG_IR_IMG_JVC
34 	&img_ir_jvc,
35 #endif
36 #ifdef CONFIG_IR_IMG_SONY
37 	&img_ir_sony,
38 #endif
39 #ifdef CONFIG_IR_IMG_SHARP
40 	&img_ir_sharp,
41 #endif
42 #ifdef CONFIG_IR_IMG_SANYO
43 	&img_ir_sanyo,
44 #endif
45 #ifdef CONFIG_IR_IMG_RC5
46 	&img_ir_rc5,
47 #endif
48 #ifdef CONFIG_IR_IMG_RC6
49 	&img_ir_rc6,
50 #endif
51 	NULL
52 };
53 
54 #define IMG_IR_F_FILTER		BIT(RC_FILTER_NORMAL)	/* enable filtering */
55 #define IMG_IR_F_WAKE		BIT(RC_FILTER_WAKEUP)	/* enable waking */
56 
57 /* code type quirks */
58 
59 #define IMG_IR_QUIRK_CODE_BROKEN	0x1	/* Decode is broken */
60 #define IMG_IR_QUIRK_CODE_LEN_INCR	0x2	/* Bit length needs increment */
61 /*
62  * The decoder generates rapid interrupts without actually having
63  * received any new data after an incomplete IR code is decoded.
64  */
65 #define IMG_IR_QUIRK_CODE_IRQ		0x4
66 
67 /* functions for preprocessing timings, ensuring max is set */
68 
69 static void img_ir_timing_preprocess(struct img_ir_timing_range *range,
70 				     unsigned int unit)
71 {
72 	if (range->max < range->min)
73 		range->max = range->min;
74 	if (unit) {
75 		/* multiply by unit and convert to microseconds */
76 		range->min = (range->min*unit)/1000;
77 		range->max = (range->max*unit + 999)/1000; /* round up */
78 	}
79 }
80 
81 static void img_ir_symbol_timing_preprocess(struct img_ir_symbol_timing *timing,
82 					    unsigned int unit)
83 {
84 	img_ir_timing_preprocess(&timing->pulse, unit);
85 	img_ir_timing_preprocess(&timing->space, unit);
86 }
87 
88 static void img_ir_timings_preprocess(struct img_ir_timings *timings,
89 				      unsigned int unit)
90 {
91 	img_ir_symbol_timing_preprocess(&timings->ldr, unit);
92 	img_ir_symbol_timing_preprocess(&timings->s00, unit);
93 	img_ir_symbol_timing_preprocess(&timings->s01, unit);
94 	img_ir_symbol_timing_preprocess(&timings->s10, unit);
95 	img_ir_symbol_timing_preprocess(&timings->s11, unit);
96 	/* default s10 and s11 to s00 and s01 if no leader */
97 	if (unit)
98 		/* multiply by unit and convert to microseconds (round up) */
99 		timings->ft.ft_min = (timings->ft.ft_min*unit + 999)/1000;
100 }
101 
102 /* functions for filling empty fields with defaults */
103 
104 static void img_ir_timing_defaults(struct img_ir_timing_range *range,
105 				   struct img_ir_timing_range *defaults)
106 {
107 	if (!range->min)
108 		range->min = defaults->min;
109 	if (!range->max)
110 		range->max = defaults->max;
111 }
112 
113 static void img_ir_symbol_timing_defaults(struct img_ir_symbol_timing *timing,
114 					  struct img_ir_symbol_timing *defaults)
115 {
116 	img_ir_timing_defaults(&timing->pulse, &defaults->pulse);
117 	img_ir_timing_defaults(&timing->space, &defaults->space);
118 }
119 
120 static void img_ir_timings_defaults(struct img_ir_timings *timings,
121 				    struct img_ir_timings *defaults)
122 {
123 	img_ir_symbol_timing_defaults(&timings->ldr, &defaults->ldr);
124 	img_ir_symbol_timing_defaults(&timings->s00, &defaults->s00);
125 	img_ir_symbol_timing_defaults(&timings->s01, &defaults->s01);
126 	img_ir_symbol_timing_defaults(&timings->s10, &defaults->s10);
127 	img_ir_symbol_timing_defaults(&timings->s11, &defaults->s11);
128 	if (!timings->ft.ft_min)
129 		timings->ft.ft_min = defaults->ft.ft_min;
130 }
131 
132 /* functions for converting timings to register values */
133 
134 /**
135  * img_ir_control() - Convert control struct to control register value.
136  * @control:	Control data
137  *
138  * Returns:	The control register value equivalent of @control.
139  */
140 static u32 img_ir_control(const struct img_ir_control *control)
141 {
142 	u32 ctrl = control->code_type << IMG_IR_CODETYPE_SHIFT;
143 	if (control->decoden)
144 		ctrl |= IMG_IR_DECODEN;
145 	if (control->hdrtog)
146 		ctrl |= IMG_IR_HDRTOG;
147 	if (control->ldrdec)
148 		ctrl |= IMG_IR_LDRDEC;
149 	if (control->decodinpol)
150 		ctrl |= IMG_IR_DECODINPOL;
151 	if (control->bitorien)
152 		ctrl |= IMG_IR_BITORIEN;
153 	if (control->d1validsel)
154 		ctrl |= IMG_IR_D1VALIDSEL;
155 	if (control->bitinv)
156 		ctrl |= IMG_IR_BITINV;
157 	if (control->decodend2)
158 		ctrl |= IMG_IR_DECODEND2;
159 	if (control->bitoriend2)
160 		ctrl |= IMG_IR_BITORIEND2;
161 	if (control->bitinvd2)
162 		ctrl |= IMG_IR_BITINVD2;
163 	return ctrl;
164 }
165 
166 /**
167  * img_ir_timing_range_convert() - Convert microsecond range.
168  * @out:	Output timing range in clock cycles with a shift.
169  * @in:		Input timing range in microseconds.
170  * @tolerance:	Tolerance as a fraction of 128 (roughly percent).
171  * @clock_hz:	IR clock rate in Hz.
172  * @shift:	Shift of output units.
173  *
174  * Converts min and max from microseconds to IR clock cycles, applies a
175  * tolerance, and shifts for the register, rounding in the right direction.
176  * Note that in and out can safely be the same object.
177  */
178 static void img_ir_timing_range_convert(struct img_ir_timing_range *out,
179 					const struct img_ir_timing_range *in,
180 					unsigned int tolerance,
181 					unsigned long clock_hz,
182 					unsigned int shift)
183 {
184 	unsigned int min = in->min;
185 	unsigned int max = in->max;
186 	/* add a tolerance */
187 	min = min - (min*tolerance >> 7);
188 	max = max + (max*tolerance >> 7);
189 	/* convert from microseconds into clock cycles */
190 	min = min*clock_hz / 1000000;
191 	max = (max*clock_hz + 999999) / 1000000; /* round up */
192 	/* apply shift and copy to output */
193 	out->min = min >> shift;
194 	out->max = (max + ((1 << shift) - 1)) >> shift; /* round up */
195 }
196 
197 /**
198  * img_ir_symbol_timing() - Convert symbol timing struct to register value.
199  * @timing:	Symbol timing data
200  * @tolerance:	Timing tolerance where 0-128 represents 0-100%
201  * @clock_hz:	Frequency of source clock in Hz
202  * @pd_shift:	Shift to apply to symbol period
203  * @w_shift:	Shift to apply to symbol width
204  *
205  * Returns:	Symbol timing register value based on arguments.
206  */
207 static u32 img_ir_symbol_timing(const struct img_ir_symbol_timing *timing,
208 				unsigned int tolerance,
209 				unsigned long clock_hz,
210 				unsigned int pd_shift,
211 				unsigned int w_shift)
212 {
213 	struct img_ir_timing_range hw_pulse, hw_period;
214 	/* we calculate period in hw_period, then convert in place */
215 	hw_period.min = timing->pulse.min + timing->space.min;
216 	hw_period.max = timing->pulse.max + timing->space.max;
217 	img_ir_timing_range_convert(&hw_period, &hw_period,
218 			tolerance, clock_hz, pd_shift);
219 	img_ir_timing_range_convert(&hw_pulse, &timing->pulse,
220 			tolerance, clock_hz, w_shift);
221 	/* construct register value */
222 	return	(hw_period.max	<< IMG_IR_PD_MAX_SHIFT)	|
223 		(hw_period.min	<< IMG_IR_PD_MIN_SHIFT)	|
224 		(hw_pulse.max	<< IMG_IR_W_MAX_SHIFT)	|
225 		(hw_pulse.min	<< IMG_IR_W_MIN_SHIFT);
226 }
227 
228 /**
229  * img_ir_free_timing() - Convert free time timing struct to register value.
230  * @timing:	Free symbol timing data
231  * @clock_hz:	Source clock frequency in Hz
232  *
233  * Returns:	Free symbol timing register value.
234  */
235 static u32 img_ir_free_timing(const struct img_ir_free_timing *timing,
236 			      unsigned long clock_hz)
237 {
238 	unsigned int minlen, maxlen, ft_min;
239 	/* minlen is only 5 bits, and round minlen to multiple of 2 */
240 	if (timing->minlen < 30)
241 		minlen = timing->minlen & -2;
242 	else
243 		minlen = 30;
244 	/* maxlen has maximum value of 48, and round maxlen to multiple of 2 */
245 	if (timing->maxlen < 48)
246 		maxlen = (timing->maxlen + 1) & -2;
247 	else
248 		maxlen = 48;
249 	/* convert and shift ft_min, rounding upwards */
250 	ft_min = (timing->ft_min*clock_hz + 999999) / 1000000;
251 	ft_min = (ft_min + 7) >> 3;
252 	/* construct register value */
253 	return	(maxlen << IMG_IR_MAXLEN_SHIFT)	|
254 		(minlen << IMG_IR_MINLEN_SHIFT)	|
255 		(ft_min << IMG_IR_FT_MIN_SHIFT);
256 }
257 
258 /**
259  * img_ir_free_timing_dynamic() - Update free time register value.
260  * @st_ft:	Static free time register value from img_ir_free_timing.
261  * @filter:	Current filter which may additionally restrict min/max len.
262  *
263  * Returns:	Updated free time register value based on the current filter.
264  */
265 static u32 img_ir_free_timing_dynamic(u32 st_ft, struct img_ir_filter *filter)
266 {
267 	unsigned int minlen, maxlen, newminlen, newmaxlen;
268 
269 	/* round minlen, maxlen to multiple of 2 */
270 	newminlen = filter->minlen & -2;
271 	newmaxlen = (filter->maxlen + 1) & -2;
272 	/* extract min/max len from register */
273 	minlen = (st_ft & IMG_IR_MINLEN) >> IMG_IR_MINLEN_SHIFT;
274 	maxlen = (st_ft & IMG_IR_MAXLEN) >> IMG_IR_MAXLEN_SHIFT;
275 	/* if the new values are more restrictive, update the register value */
276 	if (newminlen > minlen) {
277 		st_ft &= ~IMG_IR_MINLEN;
278 		st_ft |= newminlen << IMG_IR_MINLEN_SHIFT;
279 	}
280 	if (newmaxlen < maxlen) {
281 		st_ft &= ~IMG_IR_MAXLEN;
282 		st_ft |= newmaxlen << IMG_IR_MAXLEN_SHIFT;
283 	}
284 	return st_ft;
285 }
286 
287 /**
288  * img_ir_timings_convert() - Convert timings to register values
289  * @regs:	Output timing register values
290  * @timings:	Input timing data
291  * @tolerance:	Timing tolerance where 0-128 represents 0-100%
292  * @clock_hz:	Source clock frequency in Hz
293  */
294 static void img_ir_timings_convert(struct img_ir_timing_regvals *regs,
295 				   const struct img_ir_timings *timings,
296 				   unsigned int tolerance,
297 				   unsigned int clock_hz)
298 {
299 	/* leader symbol timings are divided by 16 */
300 	regs->ldr = img_ir_symbol_timing(&timings->ldr, tolerance, clock_hz,
301 			4, 4);
302 	/* other symbol timings, pd fields only are divided by 2 */
303 	regs->s00 = img_ir_symbol_timing(&timings->s00, tolerance, clock_hz,
304 			1, 0);
305 	regs->s01 = img_ir_symbol_timing(&timings->s01, tolerance, clock_hz,
306 			1, 0);
307 	regs->s10 = img_ir_symbol_timing(&timings->s10, tolerance, clock_hz,
308 			1, 0);
309 	regs->s11 = img_ir_symbol_timing(&timings->s11, tolerance, clock_hz,
310 			1, 0);
311 	regs->ft = img_ir_free_timing(&timings->ft, clock_hz);
312 }
313 
314 /**
315  * img_ir_decoder_preprocess() - Preprocess timings in decoder.
316  * @decoder:	Decoder to be preprocessed.
317  *
318  * Ensures that the symbol timing ranges are valid with respect to ordering, and
319  * does some fixed conversion on them.
320  */
321 static void img_ir_decoder_preprocess(struct img_ir_decoder *decoder)
322 {
323 	/* default tolerance */
324 	if (!decoder->tolerance)
325 		decoder->tolerance = 10; /* percent */
326 	/* and convert tolerance to fraction out of 128 */
327 	decoder->tolerance = decoder->tolerance * 128 / 100;
328 
329 	/* fill in implicit fields */
330 	img_ir_timings_preprocess(&decoder->timings, decoder->unit);
331 
332 	/* do the same for repeat timings if applicable */
333 	if (decoder->repeat) {
334 		img_ir_timings_preprocess(&decoder->rtimings, decoder->unit);
335 		img_ir_timings_defaults(&decoder->rtimings, &decoder->timings);
336 	}
337 }
338 
339 /**
340  * img_ir_decoder_convert() - Generate internal timings in decoder.
341  * @decoder:	Decoder to be converted to internal timings.
342  * @timings:	Timing register values.
343  * @clock_hz:	IR clock rate in Hz.
344  *
345  * Fills out the repeat timings and timing register values for a specific clock
346  * rate.
347  */
348 static void img_ir_decoder_convert(const struct img_ir_decoder *decoder,
349 				   struct img_ir_reg_timings *reg_timings,
350 				   unsigned int clock_hz)
351 {
352 	/* calculate control value */
353 	reg_timings->ctrl = img_ir_control(&decoder->control);
354 
355 	/* fill in implicit fields and calculate register values */
356 	img_ir_timings_convert(&reg_timings->timings, &decoder->timings,
357 			       decoder->tolerance, clock_hz);
358 
359 	/* do the same for repeat timings if applicable */
360 	if (decoder->repeat)
361 		img_ir_timings_convert(&reg_timings->rtimings,
362 				       &decoder->rtimings, decoder->tolerance,
363 				       clock_hz);
364 }
365 
366 /**
367  * img_ir_write_timings() - Write timings to the hardware now
368  * @priv:	IR private data
369  * @regs:	Timing register values to write
370  * @type:	RC filter type (RC_FILTER_*)
371  *
372  * Write timing register values @regs to the hardware, taking into account the
373  * current filter which may impose restrictions on the length of the expected
374  * data.
375  */
376 static void img_ir_write_timings(struct img_ir_priv *priv,
377 				 struct img_ir_timing_regvals *regs,
378 				 enum rc_filter_type type)
379 {
380 	struct img_ir_priv_hw *hw = &priv->hw;
381 
382 	/* filter may be more restrictive to minlen, maxlen */
383 	u32 ft = regs->ft;
384 	if (hw->flags & BIT(type))
385 		ft = img_ir_free_timing_dynamic(regs->ft, &hw->filters[type]);
386 	/* write to registers */
387 	img_ir_write(priv, IMG_IR_LEAD_SYMB_TIMING, regs->ldr);
388 	img_ir_write(priv, IMG_IR_S00_SYMB_TIMING, regs->s00);
389 	img_ir_write(priv, IMG_IR_S01_SYMB_TIMING, regs->s01);
390 	img_ir_write(priv, IMG_IR_S10_SYMB_TIMING, regs->s10);
391 	img_ir_write(priv, IMG_IR_S11_SYMB_TIMING, regs->s11);
392 	img_ir_write(priv, IMG_IR_FREE_SYMB_TIMING, ft);
393 	dev_dbg(priv->dev, "timings: ldr=%#x, s=[%#x, %#x, %#x, %#x], ft=%#x\n",
394 		regs->ldr, regs->s00, regs->s01, regs->s10, regs->s11, ft);
395 }
396 
397 static void img_ir_write_filter(struct img_ir_priv *priv,
398 				struct img_ir_filter *filter)
399 {
400 	if (filter) {
401 		dev_dbg(priv->dev, "IR filter=%016llx & %016llx\n",
402 			(unsigned long long)filter->data,
403 			(unsigned long long)filter->mask);
404 		img_ir_write(priv, IMG_IR_IRQ_MSG_DATA_LW, (u32)filter->data);
405 		img_ir_write(priv, IMG_IR_IRQ_MSG_DATA_UP, (u32)(filter->data
406 									>> 32));
407 		img_ir_write(priv, IMG_IR_IRQ_MSG_MASK_LW, (u32)filter->mask);
408 		img_ir_write(priv, IMG_IR_IRQ_MSG_MASK_UP, (u32)(filter->mask
409 									>> 32));
410 	} else {
411 		dev_dbg(priv->dev, "IR clearing filter\n");
412 		img_ir_write(priv, IMG_IR_IRQ_MSG_MASK_LW, 0);
413 		img_ir_write(priv, IMG_IR_IRQ_MSG_MASK_UP, 0);
414 	}
415 }
416 
417 /* caller must have lock */
418 static void _img_ir_set_filter(struct img_ir_priv *priv,
419 			       struct img_ir_filter *filter)
420 {
421 	struct img_ir_priv_hw *hw = &priv->hw;
422 	u32 irq_en, irq_on;
423 
424 	irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
425 	if (filter) {
426 		/* Only use the match interrupt */
427 		hw->filters[RC_FILTER_NORMAL] = *filter;
428 		hw->flags |= IMG_IR_F_FILTER;
429 		irq_on = IMG_IR_IRQ_DATA_MATCH;
430 		irq_en &= ~(IMG_IR_IRQ_DATA_VALID | IMG_IR_IRQ_DATA2_VALID);
431 	} else {
432 		/* Only use the valid interrupt */
433 		hw->flags &= ~IMG_IR_F_FILTER;
434 		irq_en &= ~IMG_IR_IRQ_DATA_MATCH;
435 		irq_on = IMG_IR_IRQ_DATA_VALID | IMG_IR_IRQ_DATA2_VALID;
436 	}
437 	irq_en |= irq_on;
438 
439 	img_ir_write_filter(priv, filter);
440 	/* clear any interrupts we're enabling so we don't handle old ones */
441 	img_ir_write(priv, IMG_IR_IRQ_CLEAR, irq_on);
442 	img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en);
443 }
444 
445 /* caller must have lock */
446 static void _img_ir_set_wake_filter(struct img_ir_priv *priv,
447 				    struct img_ir_filter *filter)
448 {
449 	struct img_ir_priv_hw *hw = &priv->hw;
450 	if (filter) {
451 		/* Enable wake, and copy filter for later */
452 		hw->filters[RC_FILTER_WAKEUP] = *filter;
453 		hw->flags |= IMG_IR_F_WAKE;
454 	} else {
455 		/* Disable wake */
456 		hw->flags &= ~IMG_IR_F_WAKE;
457 	}
458 }
459 
460 /* Callback for setting scancode filter */
461 static int img_ir_set_filter(struct rc_dev *dev, enum rc_filter_type type,
462 			     struct rc_scancode_filter *sc_filter)
463 {
464 	struct img_ir_priv *priv = dev->priv;
465 	struct img_ir_priv_hw *hw = &priv->hw;
466 	struct img_ir_filter filter, *filter_ptr = &filter;
467 	int ret = 0;
468 
469 	dev_dbg(priv->dev, "IR scancode %sfilter=%08x & %08x\n",
470 		type == RC_FILTER_WAKEUP ? "wake " : "",
471 		sc_filter->data,
472 		sc_filter->mask);
473 
474 	spin_lock_irq(&priv->lock);
475 
476 	/* filtering can always be disabled */
477 	if (!sc_filter->mask) {
478 		filter_ptr = NULL;
479 		goto set_unlock;
480 	}
481 
482 	/* current decoder must support scancode filtering */
483 	if (!hw->decoder || !hw->decoder->filter) {
484 		ret = -EINVAL;
485 		goto unlock;
486 	}
487 
488 	/* convert scancode filter to raw filter */
489 	filter.minlen = 0;
490 	filter.maxlen = ~0;
491 	if (type == RC_FILTER_NORMAL) {
492 		/* guess scancode from protocol */
493 		ret = hw->decoder->filter(sc_filter, &filter,
494 					  dev->enabled_protocols);
495 	} else {
496 		/* for wakeup user provided exact protocol variant */
497 		ret = hw->decoder->filter(sc_filter, &filter,
498 					  1ULL << dev->wakeup_protocol);
499 	}
500 	if (ret)
501 		goto unlock;
502 	dev_dbg(priv->dev, "IR raw %sfilter=%016llx & %016llx\n",
503 		type == RC_FILTER_WAKEUP ? "wake " : "",
504 		(unsigned long long)filter.data,
505 		(unsigned long long)filter.mask);
506 
507 set_unlock:
508 	/* apply raw filters */
509 	switch (type) {
510 	case RC_FILTER_NORMAL:
511 		_img_ir_set_filter(priv, filter_ptr);
512 		break;
513 	case RC_FILTER_WAKEUP:
514 		_img_ir_set_wake_filter(priv, filter_ptr);
515 		break;
516 	default:
517 		ret = -EINVAL;
518 	}
519 
520 unlock:
521 	spin_unlock_irq(&priv->lock);
522 	return ret;
523 }
524 
525 static int img_ir_set_normal_filter(struct rc_dev *dev,
526 				    struct rc_scancode_filter *sc_filter)
527 {
528 	return img_ir_set_filter(dev, RC_FILTER_NORMAL, sc_filter);
529 }
530 
531 static int img_ir_set_wakeup_filter(struct rc_dev *dev,
532 				    struct rc_scancode_filter *sc_filter)
533 {
534 	return img_ir_set_filter(dev, RC_FILTER_WAKEUP, sc_filter);
535 }
536 
537 /**
538  * img_ir_set_decoder() - Set the current decoder.
539  * @priv:	IR private data.
540  * @decoder:	Decoder to use with immediate effect.
541  * @proto:	Protocol bitmap (or 0 to use decoder->type).
542  */
543 static void img_ir_set_decoder(struct img_ir_priv *priv,
544 			       const struct img_ir_decoder *decoder,
545 			       u64 proto)
546 {
547 	struct img_ir_priv_hw *hw = &priv->hw;
548 	struct rc_dev *rdev = hw->rdev;
549 	u32 ir_status, irq_en;
550 	spin_lock_irq(&priv->lock);
551 
552 	/*
553 	 * First record that the protocol is being stopped so that the end timer
554 	 * isn't restarted while we're trying to stop it.
555 	 */
556 	hw->stopping = true;
557 
558 	/*
559 	 * Release the lock to stop the end timer, since the end timer handler
560 	 * acquires the lock and we don't want to deadlock waiting for it.
561 	 */
562 	spin_unlock_irq(&priv->lock);
563 	del_timer_sync(&hw->end_timer);
564 	del_timer_sync(&hw->suspend_timer);
565 	spin_lock_irq(&priv->lock);
566 
567 	hw->stopping = false;
568 
569 	/* switch off and disable interrupts */
570 	img_ir_write(priv, IMG_IR_CONTROL, 0);
571 	irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
572 	img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en & IMG_IR_IRQ_EDGE);
573 	img_ir_write(priv, IMG_IR_IRQ_CLEAR, IMG_IR_IRQ_ALL & ~IMG_IR_IRQ_EDGE);
574 
575 	/* ack any data already detected */
576 	ir_status = img_ir_read(priv, IMG_IR_STATUS);
577 	if (ir_status & (IMG_IR_RXDVAL | IMG_IR_RXDVALD2)) {
578 		ir_status &= ~(IMG_IR_RXDVAL | IMG_IR_RXDVALD2);
579 		img_ir_write(priv, IMG_IR_STATUS, ir_status);
580 	}
581 
582 	/* always read data to clear buffer if IR wakes the device */
583 	img_ir_read(priv, IMG_IR_DATA_LW);
584 	img_ir_read(priv, IMG_IR_DATA_UP);
585 
586 	/* switch back to normal mode */
587 	hw->mode = IMG_IR_M_NORMAL;
588 
589 	/* clear the wakeup scancode filter */
590 	rdev->scancode_wakeup_filter.data = 0;
591 	rdev->scancode_wakeup_filter.mask = 0;
592 	rdev->wakeup_protocol = RC_PROTO_UNKNOWN;
593 
594 	/* clear raw filters */
595 	_img_ir_set_filter(priv, NULL);
596 	_img_ir_set_wake_filter(priv, NULL);
597 
598 	/* clear the enabled protocols */
599 	hw->enabled_protocols = 0;
600 
601 	/* switch decoder */
602 	hw->decoder = decoder;
603 	if (!decoder)
604 		goto unlock;
605 
606 	/* set the enabled protocols */
607 	if (!proto)
608 		proto = decoder->type;
609 	hw->enabled_protocols = proto;
610 
611 	/* write the new timings */
612 	img_ir_decoder_convert(decoder, &hw->reg_timings, hw->clk_hz);
613 	img_ir_write_timings(priv, &hw->reg_timings.timings, RC_FILTER_NORMAL);
614 
615 	/* set up and enable */
616 	img_ir_write(priv, IMG_IR_CONTROL, hw->reg_timings.ctrl);
617 
618 
619 unlock:
620 	spin_unlock_irq(&priv->lock);
621 }
622 
623 /**
624  * img_ir_decoder_compatable() - Find whether a decoder will work with a device.
625  * @priv:	IR private data.
626  * @dec:	Decoder to check.
627  *
628  * Returns:	true if @dec is compatible with the device @priv refers to.
629  */
630 static bool img_ir_decoder_compatible(struct img_ir_priv *priv,
631 				      const struct img_ir_decoder *dec)
632 {
633 	unsigned int ct;
634 
635 	/* don't accept decoders using code types which aren't supported */
636 	ct = dec->control.code_type;
637 	if (priv->hw.ct_quirks[ct] & IMG_IR_QUIRK_CODE_BROKEN)
638 		return false;
639 
640 	return true;
641 }
642 
643 /**
644  * img_ir_allowed_protos() - Get allowed protocols from global decoder list.
645  * @priv:	IR private data.
646  *
647  * Returns:	Mask of protocols supported by the device @priv refers to.
648  */
649 static u64 img_ir_allowed_protos(struct img_ir_priv *priv)
650 {
651 	u64 protos = 0;
652 	struct img_ir_decoder **decp;
653 
654 	for (decp = img_ir_decoders; *decp; ++decp) {
655 		const struct img_ir_decoder *dec = *decp;
656 		if (img_ir_decoder_compatible(priv, dec))
657 			protos |= dec->type;
658 	}
659 	return protos;
660 }
661 
662 /* Callback for changing protocol using sysfs */
663 static int img_ir_change_protocol(struct rc_dev *dev, u64 *ir_type)
664 {
665 	struct img_ir_priv *priv = dev->priv;
666 	struct img_ir_priv_hw *hw = &priv->hw;
667 	struct rc_dev *rdev = hw->rdev;
668 	struct img_ir_decoder **decp;
669 	u64 wakeup_protocols;
670 
671 	if (!*ir_type) {
672 		/* disable all protocols */
673 		img_ir_set_decoder(priv, NULL, 0);
674 		goto success;
675 	}
676 	for (decp = img_ir_decoders; *decp; ++decp) {
677 		const struct img_ir_decoder *dec = *decp;
678 		if (!img_ir_decoder_compatible(priv, dec))
679 			continue;
680 		if (*ir_type & dec->type) {
681 			*ir_type &= dec->type;
682 			img_ir_set_decoder(priv, dec, *ir_type);
683 			goto success;
684 		}
685 	}
686 	return -EINVAL;
687 
688 success:
689 	/*
690 	 * Only allow matching wakeup protocols for now, and only if filtering
691 	 * is supported.
692 	 */
693 	wakeup_protocols = *ir_type;
694 	if (!hw->decoder || !hw->decoder->filter)
695 		wakeup_protocols = 0;
696 	rdev->allowed_wakeup_protocols = wakeup_protocols;
697 	return 0;
698 }
699 
700 /* Changes ir-core protocol device attribute */
701 static void img_ir_set_protocol(struct img_ir_priv *priv, u64 proto)
702 {
703 	struct rc_dev *rdev = priv->hw.rdev;
704 
705 	mutex_lock(&rdev->lock);
706 	rdev->enabled_protocols = proto;
707 	rdev->allowed_wakeup_protocols = proto;
708 	mutex_unlock(&rdev->lock);
709 }
710 
711 /* Set up IR decoders */
712 static void img_ir_init_decoders(void)
713 {
714 	struct img_ir_decoder **decp;
715 
716 	spin_lock(&img_ir_decoders_lock);
717 	if (!img_ir_decoders_preprocessed) {
718 		for (decp = img_ir_decoders; *decp; ++decp)
719 			img_ir_decoder_preprocess(*decp);
720 		img_ir_decoders_preprocessed = true;
721 	}
722 	spin_unlock(&img_ir_decoders_lock);
723 }
724 
725 #ifdef CONFIG_PM_SLEEP
726 /**
727  * img_ir_enable_wake() - Switch to wake mode.
728  * @priv:	IR private data.
729  *
730  * Returns:	non-zero if the IR can wake the system.
731  */
732 static int img_ir_enable_wake(struct img_ir_priv *priv)
733 {
734 	struct img_ir_priv_hw *hw = &priv->hw;
735 	int ret = 0;
736 
737 	spin_lock_irq(&priv->lock);
738 	if (hw->flags & IMG_IR_F_WAKE) {
739 		/* interrupt only on a match */
740 		hw->suspend_irqen = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
741 		img_ir_write(priv, IMG_IR_IRQ_ENABLE, IMG_IR_IRQ_DATA_MATCH);
742 		img_ir_write_filter(priv, &hw->filters[RC_FILTER_WAKEUP]);
743 		img_ir_write_timings(priv, &hw->reg_timings.timings,
744 				     RC_FILTER_WAKEUP);
745 		hw->mode = IMG_IR_M_WAKE;
746 		ret = 1;
747 	}
748 	spin_unlock_irq(&priv->lock);
749 	return ret;
750 }
751 
752 /**
753  * img_ir_disable_wake() - Switch out of wake mode.
754  * @priv:	IR private data
755  *
756  * Returns:	1 if the hardware should be allowed to wake from a sleep state.
757  *		0 otherwise.
758  */
759 static int img_ir_disable_wake(struct img_ir_priv *priv)
760 {
761 	struct img_ir_priv_hw *hw = &priv->hw;
762 	int ret = 0;
763 
764 	spin_lock_irq(&priv->lock);
765 	if (hw->flags & IMG_IR_F_WAKE) {
766 		/* restore normal filtering */
767 		if (hw->flags & IMG_IR_F_FILTER) {
768 			img_ir_write(priv, IMG_IR_IRQ_ENABLE,
769 				     (hw->suspend_irqen & IMG_IR_IRQ_EDGE) |
770 				     IMG_IR_IRQ_DATA_MATCH);
771 			img_ir_write_filter(priv,
772 					    &hw->filters[RC_FILTER_NORMAL]);
773 		} else {
774 			img_ir_write(priv, IMG_IR_IRQ_ENABLE,
775 				     (hw->suspend_irqen & IMG_IR_IRQ_EDGE) |
776 				     IMG_IR_IRQ_DATA_VALID |
777 				     IMG_IR_IRQ_DATA2_VALID);
778 			img_ir_write_filter(priv, NULL);
779 		}
780 		img_ir_write_timings(priv, &hw->reg_timings.timings,
781 				     RC_FILTER_NORMAL);
782 		hw->mode = IMG_IR_M_NORMAL;
783 		ret = 1;
784 	}
785 	spin_unlock_irq(&priv->lock);
786 	return ret;
787 }
788 #endif /* CONFIG_PM_SLEEP */
789 
790 /* lock must be held */
791 static void img_ir_begin_repeat(struct img_ir_priv *priv)
792 {
793 	struct img_ir_priv_hw *hw = &priv->hw;
794 	if (hw->mode == IMG_IR_M_NORMAL) {
795 		/* switch to repeat timings */
796 		img_ir_write(priv, IMG_IR_CONTROL, 0);
797 		hw->mode = IMG_IR_M_REPEATING;
798 		img_ir_write_timings(priv, &hw->reg_timings.rtimings,
799 				     RC_FILTER_NORMAL);
800 		img_ir_write(priv, IMG_IR_CONTROL, hw->reg_timings.ctrl);
801 	}
802 }
803 
804 /* lock must be held */
805 static void img_ir_end_repeat(struct img_ir_priv *priv)
806 {
807 	struct img_ir_priv_hw *hw = &priv->hw;
808 	if (hw->mode == IMG_IR_M_REPEATING) {
809 		/* switch to normal timings */
810 		img_ir_write(priv, IMG_IR_CONTROL, 0);
811 		hw->mode = IMG_IR_M_NORMAL;
812 		img_ir_write_timings(priv, &hw->reg_timings.timings,
813 				     RC_FILTER_NORMAL);
814 		img_ir_write(priv, IMG_IR_CONTROL, hw->reg_timings.ctrl);
815 	}
816 }
817 
818 /* lock must be held */
819 static void img_ir_handle_data(struct img_ir_priv *priv, u32 len, u64 raw)
820 {
821 	struct img_ir_priv_hw *hw = &priv->hw;
822 	const struct img_ir_decoder *dec = hw->decoder;
823 	int ret = IMG_IR_SCANCODE;
824 	struct img_ir_scancode_req request;
825 
826 	request.protocol = RC_PROTO_UNKNOWN;
827 	request.toggle   = 0;
828 
829 	if (dec->scancode)
830 		ret = dec->scancode(len, raw, hw->enabled_protocols, &request);
831 	else if (len >= 32)
832 		request.scancode = (u32)raw;
833 	else if (len < 32)
834 		request.scancode = (u32)raw & ((1 << len)-1);
835 	dev_dbg(priv->dev, "data (%u bits) = %#llx\n",
836 		len, (unsigned long long)raw);
837 	if (ret == IMG_IR_SCANCODE) {
838 		dev_dbg(priv->dev, "decoded scan code %#x, toggle %u\n",
839 			request.scancode, request.toggle);
840 		rc_keydown(hw->rdev, request.protocol, request.scancode,
841 			   request.toggle);
842 		img_ir_end_repeat(priv);
843 	} else if (ret == IMG_IR_REPEATCODE) {
844 		if (hw->mode == IMG_IR_M_REPEATING) {
845 			dev_dbg(priv->dev, "decoded repeat code\n");
846 			rc_repeat(hw->rdev);
847 		} else {
848 			dev_dbg(priv->dev, "decoded unexpected repeat code, ignoring\n");
849 		}
850 	} else {
851 		dev_dbg(priv->dev, "decode failed (%d)\n", ret);
852 		return;
853 	}
854 
855 
856 	/* we mustn't update the end timer while trying to stop it */
857 	if (dec->repeat && !hw->stopping) {
858 		unsigned long interval;
859 
860 		img_ir_begin_repeat(priv);
861 
862 		/* update timer, but allowing for 1/8th tolerance */
863 		interval = dec->repeat + (dec->repeat >> 3);
864 		mod_timer(&hw->end_timer,
865 			  jiffies + msecs_to_jiffies(interval));
866 	}
867 }
868 
869 /* timer function to end waiting for repeat. */
870 static void img_ir_end_timer(struct timer_list *t)
871 {
872 	struct img_ir_priv *priv = from_timer(priv, t, hw.end_timer);
873 
874 	spin_lock_irq(&priv->lock);
875 	img_ir_end_repeat(priv);
876 	spin_unlock_irq(&priv->lock);
877 }
878 
879 /*
880  * Timer function to re-enable the current protocol after it had been
881  * cleared when invalid interrupts were generated due to a quirk in the
882  * img-ir decoder.
883  */
884 static void img_ir_suspend_timer(struct timer_list *t)
885 {
886 	struct img_ir_priv *priv = from_timer(priv, t, hw.suspend_timer);
887 
888 	spin_lock_irq(&priv->lock);
889 	/*
890 	 * Don't overwrite enabled valid/match IRQs if they have already been
891 	 * changed by e.g. a filter change.
892 	 */
893 	if ((priv->hw.quirk_suspend_irq & IMG_IR_IRQ_EDGE) ==
894 				img_ir_read(priv, IMG_IR_IRQ_ENABLE))
895 		img_ir_write(priv, IMG_IR_IRQ_ENABLE,
896 					priv->hw.quirk_suspend_irq);
897 	/* enable */
898 	img_ir_write(priv, IMG_IR_CONTROL, priv->hw.reg_timings.ctrl);
899 	spin_unlock_irq(&priv->lock);
900 }
901 
902 #ifdef CONFIG_COMMON_CLK
903 static void img_ir_change_frequency(struct img_ir_priv *priv,
904 				    struct clk_notifier_data *change)
905 {
906 	struct img_ir_priv_hw *hw = &priv->hw;
907 
908 	dev_dbg(priv->dev, "clk changed %lu HZ -> %lu HZ\n",
909 		change->old_rate, change->new_rate);
910 
911 	spin_lock_irq(&priv->lock);
912 	if (hw->clk_hz == change->new_rate)
913 		goto unlock;
914 	hw->clk_hz = change->new_rate;
915 	/* refresh current timings */
916 	if (hw->decoder) {
917 		img_ir_decoder_convert(hw->decoder, &hw->reg_timings,
918 				       hw->clk_hz);
919 		switch (hw->mode) {
920 		case IMG_IR_M_NORMAL:
921 			img_ir_write_timings(priv, &hw->reg_timings.timings,
922 					     RC_FILTER_NORMAL);
923 			break;
924 		case IMG_IR_M_REPEATING:
925 			img_ir_write_timings(priv, &hw->reg_timings.rtimings,
926 					     RC_FILTER_NORMAL);
927 			break;
928 #ifdef CONFIG_PM_SLEEP
929 		case IMG_IR_M_WAKE:
930 			img_ir_write_timings(priv, &hw->reg_timings.timings,
931 					     RC_FILTER_WAKEUP);
932 			break;
933 #endif
934 		}
935 	}
936 unlock:
937 	spin_unlock_irq(&priv->lock);
938 }
939 
940 static int img_ir_clk_notify(struct notifier_block *self, unsigned long action,
941 			     void *data)
942 {
943 	struct img_ir_priv *priv = container_of(self, struct img_ir_priv,
944 						hw.clk_nb);
945 	switch (action) {
946 	case POST_RATE_CHANGE:
947 		img_ir_change_frequency(priv, data);
948 		break;
949 	default:
950 		break;
951 	}
952 	return NOTIFY_OK;
953 }
954 #endif /* CONFIG_COMMON_CLK */
955 
956 /* called with priv->lock held */
957 void img_ir_isr_hw(struct img_ir_priv *priv, u32 irq_status)
958 {
959 	struct img_ir_priv_hw *hw = &priv->hw;
960 	u32 ir_status, len, lw, up;
961 	unsigned int ct;
962 
963 	/* use the current decoder */
964 	if (!hw->decoder)
965 		return;
966 
967 	ct = hw->decoder->control.code_type;
968 
969 	ir_status = img_ir_read(priv, IMG_IR_STATUS);
970 	if (!(ir_status & (IMG_IR_RXDVAL | IMG_IR_RXDVALD2))) {
971 		if (!(priv->hw.ct_quirks[ct] & IMG_IR_QUIRK_CODE_IRQ) ||
972 				hw->stopping)
973 			return;
974 		/*
975 		 * The below functionality is added as a work around to stop
976 		 * multiple Interrupts generated when an incomplete IR code is
977 		 * received by the decoder.
978 		 * The decoder generates rapid interrupts without actually
979 		 * having received any new data. After a single interrupt it's
980 		 * expected to clear up, but instead multiple interrupts are
981 		 * rapidly generated. only way to get out of this loop is to
982 		 * reset the control register after a short delay.
983 		 */
984 		img_ir_write(priv, IMG_IR_CONTROL, 0);
985 		hw->quirk_suspend_irq = img_ir_read(priv, IMG_IR_IRQ_ENABLE);
986 		img_ir_write(priv, IMG_IR_IRQ_ENABLE,
987 			     hw->quirk_suspend_irq & IMG_IR_IRQ_EDGE);
988 
989 		/* Timer activated to re-enable the protocol. */
990 		mod_timer(&hw->suspend_timer,
991 			  jiffies + msecs_to_jiffies(5));
992 		return;
993 	}
994 	ir_status &= ~(IMG_IR_RXDVAL | IMG_IR_RXDVALD2);
995 	img_ir_write(priv, IMG_IR_STATUS, ir_status);
996 
997 	len = (ir_status & IMG_IR_RXDLEN) >> IMG_IR_RXDLEN_SHIFT;
998 	/* some versions report wrong length for certain code types */
999 	if (hw->ct_quirks[ct] & IMG_IR_QUIRK_CODE_LEN_INCR)
1000 		++len;
1001 
1002 	lw = img_ir_read(priv, IMG_IR_DATA_LW);
1003 	up = img_ir_read(priv, IMG_IR_DATA_UP);
1004 	img_ir_handle_data(priv, len, (u64)up << 32 | lw);
1005 }
1006 
1007 void img_ir_setup_hw(struct img_ir_priv *priv)
1008 {
1009 	struct img_ir_decoder **decp;
1010 
1011 	if (!priv->hw.rdev)
1012 		return;
1013 
1014 	/* Use the first available decoder (or disable stuff if NULL) */
1015 	for (decp = img_ir_decoders; *decp; ++decp) {
1016 		const struct img_ir_decoder *dec = *decp;
1017 		if (img_ir_decoder_compatible(priv, dec)) {
1018 			img_ir_set_protocol(priv, dec->type);
1019 			img_ir_set_decoder(priv, dec, 0);
1020 			return;
1021 		}
1022 	}
1023 	img_ir_set_decoder(priv, NULL, 0);
1024 }
1025 
1026 /**
1027  * img_ir_probe_hw_caps() - Probe capabilities of the hardware.
1028  * @priv:	IR private data.
1029  */
1030 static void img_ir_probe_hw_caps(struct img_ir_priv *priv)
1031 {
1032 	struct img_ir_priv_hw *hw = &priv->hw;
1033 	/*
1034 	 * When a version of the block becomes available without these quirks,
1035 	 * they'll have to depend on the core revision.
1036 	 */
1037 	hw->ct_quirks[IMG_IR_CODETYPE_PULSELEN]
1038 		|= IMG_IR_QUIRK_CODE_LEN_INCR;
1039 	hw->ct_quirks[IMG_IR_CODETYPE_BIPHASE]
1040 		|= IMG_IR_QUIRK_CODE_IRQ;
1041 	hw->ct_quirks[IMG_IR_CODETYPE_2BITPULSEPOS]
1042 		|= IMG_IR_QUIRK_CODE_BROKEN;
1043 }
1044 
1045 int img_ir_probe_hw(struct img_ir_priv *priv)
1046 {
1047 	struct img_ir_priv_hw *hw = &priv->hw;
1048 	struct rc_dev *rdev;
1049 	int error;
1050 
1051 	/* Ensure hardware decoders have been preprocessed */
1052 	img_ir_init_decoders();
1053 
1054 	/* Probe hardware capabilities */
1055 	img_ir_probe_hw_caps(priv);
1056 
1057 	/* Set up the end timer */
1058 	timer_setup(&hw->end_timer, img_ir_end_timer, 0);
1059 	timer_setup(&hw->suspend_timer, img_ir_suspend_timer, 0);
1060 
1061 	/* Register a clock notifier */
1062 	if (!IS_ERR(priv->clk)) {
1063 		hw->clk_hz = clk_get_rate(priv->clk);
1064 #ifdef CONFIG_COMMON_CLK
1065 		hw->clk_nb.notifier_call = img_ir_clk_notify;
1066 		error = clk_notifier_register(priv->clk, &hw->clk_nb);
1067 		if (error)
1068 			dev_warn(priv->dev,
1069 				 "failed to register clock notifier\n");
1070 #endif
1071 	} else {
1072 		hw->clk_hz = 32768;
1073 	}
1074 
1075 	/* Allocate hardware decoder */
1076 	hw->rdev = rdev = rc_allocate_device(RC_DRIVER_SCANCODE);
1077 	if (!rdev) {
1078 		dev_err(priv->dev, "cannot allocate input device\n");
1079 		error = -ENOMEM;
1080 		goto err_alloc_rc;
1081 	}
1082 	rdev->priv = priv;
1083 	rdev->map_name = RC_MAP_EMPTY;
1084 	rdev->allowed_protocols = img_ir_allowed_protos(priv);
1085 	rdev->device_name = "IMG Infrared Decoder";
1086 	rdev->s_filter = img_ir_set_normal_filter;
1087 	rdev->s_wakeup_filter = img_ir_set_wakeup_filter;
1088 
1089 	/* Register hardware decoder */
1090 	error = rc_register_device(rdev);
1091 	if (error) {
1092 		dev_err(priv->dev, "failed to register IR input device\n");
1093 		goto err_register_rc;
1094 	}
1095 
1096 	/*
1097 	 * Set this after rc_register_device as no protocols have been
1098 	 * registered yet.
1099 	 */
1100 	rdev->change_protocol = img_ir_change_protocol;
1101 
1102 	device_init_wakeup(priv->dev, 1);
1103 
1104 	return 0;
1105 
1106 err_register_rc:
1107 	img_ir_set_decoder(priv, NULL, 0);
1108 	hw->rdev = NULL;
1109 	rc_free_device(rdev);
1110 err_alloc_rc:
1111 #ifdef CONFIG_COMMON_CLK
1112 	if (!IS_ERR(priv->clk))
1113 		clk_notifier_unregister(priv->clk, &hw->clk_nb);
1114 #endif
1115 	return error;
1116 }
1117 
1118 void img_ir_remove_hw(struct img_ir_priv *priv)
1119 {
1120 	struct img_ir_priv_hw *hw = &priv->hw;
1121 	struct rc_dev *rdev = hw->rdev;
1122 	if (!rdev)
1123 		return;
1124 	img_ir_set_decoder(priv, NULL, 0);
1125 	hw->rdev = NULL;
1126 	rc_unregister_device(rdev);
1127 #ifdef CONFIG_COMMON_CLK
1128 	if (!IS_ERR(priv->clk))
1129 		clk_notifier_unregister(priv->clk, &hw->clk_nb);
1130 #endif
1131 }
1132 
1133 #ifdef CONFIG_PM_SLEEP
1134 int img_ir_suspend(struct device *dev)
1135 {
1136 	struct img_ir_priv *priv = dev_get_drvdata(dev);
1137 
1138 	if (device_may_wakeup(dev) && img_ir_enable_wake(priv))
1139 		enable_irq_wake(priv->irq);
1140 	return 0;
1141 }
1142 
1143 int img_ir_resume(struct device *dev)
1144 {
1145 	struct img_ir_priv *priv = dev_get_drvdata(dev);
1146 
1147 	if (device_may_wakeup(dev) && img_ir_disable_wake(priv))
1148 		disable_irq_wake(priv->irq);
1149 	return 0;
1150 }
1151 #endif	/* CONFIG_PM_SLEEP */
1152