1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for the Conexant CX23885/7/8 PCIe bridge
4  *
5  *  CX23888 Integrated Consumer Infrared Controller
6  *
7  *  Copyright (C) 2009  Andy Walls <awalls@md.metrocast.net>
8  */
9 
10 #include "cx23885.h"
11 #include "cx23888-ir.h"
12 
13 #include <linux/kfifo.h>
14 #include <linux/slab.h>
15 
16 #include <media/v4l2-device.h>
17 #include <media/rc-core.h>
18 
19 static unsigned int ir_888_debug;
20 module_param(ir_888_debug, int, 0644);
21 MODULE_PARM_DESC(ir_888_debug, "enable debug messages [CX23888 IR controller]");
22 
23 #define CX23888_IR_REG_BASE	0x170000
24 /*
25  * These CX23888 register offsets have a straightforward one to one mapping
26  * to the CX23885 register offsets of 0x200 through 0x218
27  */
28 #define CX23888_IR_CNTRL_REG	0x170000
29 #define CNTRL_WIN_3_3	0x00000000
30 #define CNTRL_WIN_4_3	0x00000001
31 #define CNTRL_WIN_3_4	0x00000002
32 #define CNTRL_WIN_4_4	0x00000003
33 #define CNTRL_WIN	0x00000003
34 #define CNTRL_EDG_NONE	0x00000000
35 #define CNTRL_EDG_FALL	0x00000004
36 #define CNTRL_EDG_RISE	0x00000008
37 #define CNTRL_EDG_BOTH	0x0000000C
38 #define CNTRL_EDG	0x0000000C
39 #define CNTRL_DMD	0x00000010
40 #define CNTRL_MOD	0x00000020
41 #define CNTRL_RFE	0x00000040
42 #define CNTRL_TFE	0x00000080
43 #define CNTRL_RXE	0x00000100
44 #define CNTRL_TXE	0x00000200
45 #define CNTRL_RIC	0x00000400
46 #define CNTRL_TIC	0x00000800
47 #define CNTRL_CPL	0x00001000
48 #define CNTRL_LBM	0x00002000
49 #define CNTRL_R		0x00004000
50 /* CX23888 specific control flag */
51 #define CNTRL_IVO	0x00008000
52 
53 #define CX23888_IR_TXCLK_REG	0x170004
54 #define TXCLK_TCD	0x0000FFFF
55 
56 #define CX23888_IR_RXCLK_REG	0x170008
57 #define RXCLK_RCD	0x0000FFFF
58 
59 #define CX23888_IR_CDUTY_REG	0x17000C
60 #define CDUTY_CDC	0x0000000F
61 
62 #define CX23888_IR_STATS_REG	0x170010
63 #define STATS_RTO	0x00000001
64 #define STATS_ROR	0x00000002
65 #define STATS_RBY	0x00000004
66 #define STATS_TBY	0x00000008
67 #define STATS_RSR	0x00000010
68 #define STATS_TSR	0x00000020
69 
70 #define CX23888_IR_IRQEN_REG	0x170014
71 #define IRQEN_RTE	0x00000001
72 #define IRQEN_ROE	0x00000002
73 #define IRQEN_RSE	0x00000010
74 #define IRQEN_TSE	0x00000020
75 
76 #define CX23888_IR_FILTR_REG	0x170018
77 #define FILTR_LPF	0x0000FFFF
78 
79 /* This register doesn't follow the pattern; it's 0x23C on a CX23885 */
80 #define CX23888_IR_FIFO_REG	0x170040
81 #define FIFO_RXTX	0x0000FFFF
82 #define FIFO_RXTX_LVL	0x00010000
83 #define FIFO_RXTX_RTO	0x0001FFFF
84 #define FIFO_RX_NDV	0x00020000
85 #define FIFO_RX_DEPTH	8
86 #define FIFO_TX_DEPTH	8
87 
88 /* CX23888 unique registers */
89 #define CX23888_IR_SEEDP_REG	0x17001C
90 #define CX23888_IR_TIMOL_REG	0x170020
91 #define CX23888_IR_WAKE0_REG	0x170024
92 #define CX23888_IR_WAKE1_REG	0x170028
93 #define CX23888_IR_WAKE2_REG	0x17002C
94 #define CX23888_IR_MASK0_REG	0x170030
95 #define CX23888_IR_MASK1_REG	0x170034
96 #define CX23888_IR_MAKS2_REG	0x170038
97 #define CX23888_IR_DPIPG_REG	0x17003C
98 #define CX23888_IR_LEARN_REG	0x170044
99 
100 #define CX23888_VIDCLK_FREQ	108000000 /* 108 MHz, BT.656 */
101 #define CX23888_IR_REFCLK_FREQ	(CX23888_VIDCLK_FREQ / 2)
102 
103 /*
104  * We use this union internally for convenience, but callers to tx_write
105  * and rx_read will be expecting records of type struct ir_raw_event.
106  * Always ensure the size of this union is dictated by struct ir_raw_event.
107  */
108 union cx23888_ir_fifo_rec {
109 	u32 hw_fifo_data;
110 	struct ir_raw_event ir_core_data;
111 };
112 
113 #define CX23888_IR_RX_KFIFO_SIZE    (256 * sizeof(union cx23888_ir_fifo_rec))
114 #define CX23888_IR_TX_KFIFO_SIZE    (256 * sizeof(union cx23888_ir_fifo_rec))
115 
116 struct cx23888_ir_state {
117 	struct v4l2_subdev sd;
118 	struct cx23885_dev *dev;
119 
120 	struct v4l2_subdev_ir_parameters rx_params;
121 	struct mutex rx_params_lock;
122 	atomic_t rxclk_divider;
123 	atomic_t rx_invert;
124 
125 	struct kfifo rx_kfifo;
126 	spinlock_t rx_kfifo_lock;
127 
128 	struct v4l2_subdev_ir_parameters tx_params;
129 	struct mutex tx_params_lock;
130 	atomic_t txclk_divider;
131 };
132 
133 static inline struct cx23888_ir_state *to_state(struct v4l2_subdev *sd)
134 {
135 	return v4l2_get_subdevdata(sd);
136 }
137 
138 /*
139  * IR register block read and write functions
140  */
141 static
142 inline int cx23888_ir_write4(struct cx23885_dev *dev, u32 addr, u32 value)
143 {
144 	cx_write(addr, value);
145 	return 0;
146 }
147 
148 static inline u32 cx23888_ir_read4(struct cx23885_dev *dev, u32 addr)
149 {
150 	return cx_read(addr);
151 }
152 
153 static inline int cx23888_ir_and_or4(struct cx23885_dev *dev, u32 addr,
154 				     u32 and_mask, u32 or_value)
155 {
156 	cx_andor(addr, ~and_mask, or_value);
157 	return 0;
158 }
159 
160 /*
161  * Rx and Tx Clock Divider register computations
162  *
163  * Note the largest clock divider value of 0xffff corresponds to:
164  *	(0xffff + 1) * 1000 / 108/2 MHz = 1,213,629.629... ns
165  * which fits in 21 bits, so we'll use unsigned int for time arguments.
166  */
167 static inline u16 count_to_clock_divider(unsigned int d)
168 {
169 	if (d > RXCLK_RCD + 1)
170 		d = RXCLK_RCD;
171 	else if (d < 2)
172 		d = 1;
173 	else
174 		d--;
175 	return (u16) d;
176 }
177 
178 static inline u16 carrier_freq_to_clock_divider(unsigned int freq)
179 {
180 	return count_to_clock_divider(
181 			  DIV_ROUND_CLOSEST(CX23888_IR_REFCLK_FREQ, freq * 16));
182 }
183 
184 static inline unsigned int clock_divider_to_carrier_freq(unsigned int divider)
185 {
186 	return DIV_ROUND_CLOSEST(CX23888_IR_REFCLK_FREQ, (divider + 1) * 16);
187 }
188 
189 static inline unsigned int clock_divider_to_freq(unsigned int divider,
190 						 unsigned int rollovers)
191 {
192 	return DIV_ROUND_CLOSEST(CX23888_IR_REFCLK_FREQ,
193 				 (divider + 1) * rollovers);
194 }
195 
196 /*
197  * Low Pass Filter register calculations
198  *
199  * Note the largest count value of 0xffff corresponds to:
200  *	0xffff * 1000 / 108/2 MHz = 1,213,611.11... ns
201  * which fits in 21 bits, so we'll use unsigned int for time arguments.
202  */
203 static inline u16 count_to_lpf_count(unsigned int d)
204 {
205 	if (d > FILTR_LPF)
206 		d = FILTR_LPF;
207 	else if (d < 4)
208 		d = 0;
209 	return (u16) d;
210 }
211 
212 static inline u16 ns_to_lpf_count(unsigned int ns)
213 {
214 	return count_to_lpf_count(
215 		DIV_ROUND_CLOSEST(CX23888_IR_REFCLK_FREQ / 1000000 * ns, 1000));
216 }
217 
218 static inline unsigned int lpf_count_to_ns(unsigned int count)
219 {
220 	/* Duration of the Low Pass Filter rejection window in ns */
221 	return DIV_ROUND_CLOSEST(count * 1000,
222 				 CX23888_IR_REFCLK_FREQ / 1000000);
223 }
224 
225 static inline unsigned int lpf_count_to_us(unsigned int count)
226 {
227 	/* Duration of the Low Pass Filter rejection window in us */
228 	return DIV_ROUND_CLOSEST(count, CX23888_IR_REFCLK_FREQ / 1000000);
229 }
230 
231 /*
232  * FIFO register pulse width count computations
233  */
234 static u32 clock_divider_to_resolution(u16 divider)
235 {
236 	/*
237 	 * Resolution is the duration of 1 tick of the readable portion of
238 	 * of the pulse width counter as read from the FIFO.  The two lsb's are
239 	 * not readable, hence the << 2.  This function returns ns.
240 	 */
241 	return DIV_ROUND_CLOSEST((1 << 2)  * ((u32) divider + 1) * 1000,
242 				 CX23888_IR_REFCLK_FREQ / 1000000);
243 }
244 
245 static u64 pulse_width_count_to_ns(u16 count, u16 divider)
246 {
247 	u64 n;
248 	u32 rem;
249 
250 	/*
251 	 * The 2 lsb's of the pulse width timer count are not readable, hence
252 	 * the (count << 2) | 0x3
253 	 */
254 	n = (((u64) count << 2) | 0x3) * (divider + 1) * 1000; /* millicycles */
255 	rem = do_div(n, CX23888_IR_REFCLK_FREQ / 1000000);     /* / MHz => ns */
256 	if (rem >= CX23888_IR_REFCLK_FREQ / 1000000 / 2)
257 		n++;
258 	return n;
259 }
260 
261 static unsigned int pulse_width_count_to_us(u16 count, u16 divider)
262 {
263 	u64 n;
264 	u32 rem;
265 
266 	/*
267 	 * The 2 lsb's of the pulse width timer count are not readable, hence
268 	 * the (count << 2) | 0x3
269 	 */
270 	n = (((u64) count << 2) | 0x3) * (divider + 1);    /* cycles      */
271 	rem = do_div(n, CX23888_IR_REFCLK_FREQ / 1000000); /* / MHz => us */
272 	if (rem >= CX23888_IR_REFCLK_FREQ / 1000000 / 2)
273 		n++;
274 	return (unsigned int) n;
275 }
276 
277 /*
278  * Pulse Clocks computations: Combined Pulse Width Count & Rx Clock Counts
279  *
280  * The total pulse clock count is an 18 bit pulse width timer count as the most
281  * significant part and (up to) 16 bit clock divider count as a modulus.
282  * When the Rx clock divider ticks down to 0, it increments the 18 bit pulse
283  * width timer count's least significant bit.
284  */
285 static u64 ns_to_pulse_clocks(u32 ns)
286 {
287 	u64 clocks;
288 	u32 rem;
289 	clocks = CX23888_IR_REFCLK_FREQ / 1000000 * (u64) ns; /* millicycles  */
290 	rem = do_div(clocks, 1000);                         /* /1000 = cycles */
291 	if (rem >= 1000 / 2)
292 		clocks++;
293 	return clocks;
294 }
295 
296 static u16 pulse_clocks_to_clock_divider(u64 count)
297 {
298 	do_div(count, (FIFO_RXTX << 2) | 0x3);
299 
300 	/* net result needs to be rounded down and decremented by 1 */
301 	if (count > RXCLK_RCD + 1)
302 		count = RXCLK_RCD;
303 	else if (count < 2)
304 		count = 1;
305 	else
306 		count--;
307 	return (u16) count;
308 }
309 
310 /*
311  * IR Control Register helpers
312  */
313 enum tx_fifo_watermark {
314 	TX_FIFO_HALF_EMPTY = 0,
315 	TX_FIFO_EMPTY      = CNTRL_TIC,
316 };
317 
318 enum rx_fifo_watermark {
319 	RX_FIFO_HALF_FULL = 0,
320 	RX_FIFO_NOT_EMPTY = CNTRL_RIC,
321 };
322 
323 static inline void control_tx_irq_watermark(struct cx23885_dev *dev,
324 					    enum tx_fifo_watermark level)
325 {
326 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_TIC, level);
327 }
328 
329 static inline void control_rx_irq_watermark(struct cx23885_dev *dev,
330 					    enum rx_fifo_watermark level)
331 {
332 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_RIC, level);
333 }
334 
335 static inline void control_tx_enable(struct cx23885_dev *dev, bool enable)
336 {
337 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~(CNTRL_TXE | CNTRL_TFE),
338 			   enable ? (CNTRL_TXE | CNTRL_TFE) : 0);
339 }
340 
341 static inline void control_rx_enable(struct cx23885_dev *dev, bool enable)
342 {
343 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~(CNTRL_RXE | CNTRL_RFE),
344 			   enable ? (CNTRL_RXE | CNTRL_RFE) : 0);
345 }
346 
347 static inline void control_tx_modulation_enable(struct cx23885_dev *dev,
348 						bool enable)
349 {
350 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_MOD,
351 			   enable ? CNTRL_MOD : 0);
352 }
353 
354 static inline void control_rx_demodulation_enable(struct cx23885_dev *dev,
355 						  bool enable)
356 {
357 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_DMD,
358 			   enable ? CNTRL_DMD : 0);
359 }
360 
361 static inline void control_rx_s_edge_detection(struct cx23885_dev *dev,
362 					       u32 edge_types)
363 {
364 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_EDG_BOTH,
365 			   edge_types & CNTRL_EDG_BOTH);
366 }
367 
368 static void control_rx_s_carrier_window(struct cx23885_dev *dev,
369 					unsigned int carrier,
370 					unsigned int *carrier_range_low,
371 					unsigned int *carrier_range_high)
372 {
373 	u32 v;
374 	unsigned int c16 = carrier * 16;
375 
376 	if (*carrier_range_low < DIV_ROUND_CLOSEST(c16, 16 + 3)) {
377 		v = CNTRL_WIN_3_4;
378 		*carrier_range_low = DIV_ROUND_CLOSEST(c16, 16 + 4);
379 	} else {
380 		v = CNTRL_WIN_3_3;
381 		*carrier_range_low = DIV_ROUND_CLOSEST(c16, 16 + 3);
382 	}
383 
384 	if (*carrier_range_high > DIV_ROUND_CLOSEST(c16, 16 - 3)) {
385 		v |= CNTRL_WIN_4_3;
386 		*carrier_range_high = DIV_ROUND_CLOSEST(c16, 16 - 4);
387 	} else {
388 		v |= CNTRL_WIN_3_3;
389 		*carrier_range_high = DIV_ROUND_CLOSEST(c16, 16 - 3);
390 	}
391 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_WIN, v);
392 }
393 
394 static inline void control_tx_polarity_invert(struct cx23885_dev *dev,
395 					      bool invert)
396 {
397 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_CPL,
398 			   invert ? CNTRL_CPL : 0);
399 }
400 
401 static inline void control_tx_level_invert(struct cx23885_dev *dev,
402 					  bool invert)
403 {
404 	cx23888_ir_and_or4(dev, CX23888_IR_CNTRL_REG, ~CNTRL_IVO,
405 			   invert ? CNTRL_IVO : 0);
406 }
407 
408 /*
409  * IR Rx & Tx Clock Register helpers
410  */
411 static unsigned int txclk_tx_s_carrier(struct cx23885_dev *dev,
412 				       unsigned int freq,
413 				       u16 *divider)
414 {
415 	*divider = carrier_freq_to_clock_divider(freq);
416 	cx23888_ir_write4(dev, CX23888_IR_TXCLK_REG, *divider);
417 	return clock_divider_to_carrier_freq(*divider);
418 }
419 
420 static unsigned int rxclk_rx_s_carrier(struct cx23885_dev *dev,
421 				       unsigned int freq,
422 				       u16 *divider)
423 {
424 	*divider = carrier_freq_to_clock_divider(freq);
425 	cx23888_ir_write4(dev, CX23888_IR_RXCLK_REG, *divider);
426 	return clock_divider_to_carrier_freq(*divider);
427 }
428 
429 static u32 txclk_tx_s_max_pulse_width(struct cx23885_dev *dev, u32 ns,
430 				      u16 *divider)
431 {
432 	u64 pulse_clocks;
433 
434 	if (ns > IR_MAX_DURATION)
435 		ns = IR_MAX_DURATION;
436 	pulse_clocks = ns_to_pulse_clocks(ns);
437 	*divider = pulse_clocks_to_clock_divider(pulse_clocks);
438 	cx23888_ir_write4(dev, CX23888_IR_TXCLK_REG, *divider);
439 	return (u32) pulse_width_count_to_ns(FIFO_RXTX, *divider);
440 }
441 
442 static u32 rxclk_rx_s_max_pulse_width(struct cx23885_dev *dev, u32 ns,
443 				      u16 *divider)
444 {
445 	u64 pulse_clocks;
446 
447 	if (ns > IR_MAX_DURATION)
448 		ns = IR_MAX_DURATION;
449 	pulse_clocks = ns_to_pulse_clocks(ns);
450 	*divider = pulse_clocks_to_clock_divider(pulse_clocks);
451 	cx23888_ir_write4(dev, CX23888_IR_RXCLK_REG, *divider);
452 	return (u32) pulse_width_count_to_ns(FIFO_RXTX, *divider);
453 }
454 
455 /*
456  * IR Tx Carrier Duty Cycle register helpers
457  */
458 static unsigned int cduty_tx_s_duty_cycle(struct cx23885_dev *dev,
459 					  unsigned int duty_cycle)
460 {
461 	u32 n;
462 	n = DIV_ROUND_CLOSEST(duty_cycle * 100, 625); /* 16ths of 100% */
463 	if (n != 0)
464 		n--;
465 	if (n > 15)
466 		n = 15;
467 	cx23888_ir_write4(dev, CX23888_IR_CDUTY_REG, n);
468 	return DIV_ROUND_CLOSEST((n + 1) * 100, 16);
469 }
470 
471 /*
472  * IR Filter Register helpers
473  */
474 static u32 filter_rx_s_min_width(struct cx23885_dev *dev, u32 min_width_ns)
475 {
476 	u32 count = ns_to_lpf_count(min_width_ns);
477 	cx23888_ir_write4(dev, CX23888_IR_FILTR_REG, count);
478 	return lpf_count_to_ns(count);
479 }
480 
481 /*
482  * IR IRQ Enable Register helpers
483  */
484 static inline void irqenable_rx(struct cx23885_dev *dev, u32 mask)
485 {
486 	mask &= (IRQEN_RTE | IRQEN_ROE | IRQEN_RSE);
487 	cx23888_ir_and_or4(dev, CX23888_IR_IRQEN_REG,
488 			   ~(IRQEN_RTE | IRQEN_ROE | IRQEN_RSE), mask);
489 }
490 
491 static inline void irqenable_tx(struct cx23885_dev *dev, u32 mask)
492 {
493 	mask &= IRQEN_TSE;
494 	cx23888_ir_and_or4(dev, CX23888_IR_IRQEN_REG, ~IRQEN_TSE, mask);
495 }
496 
497 /*
498  * V4L2 Subdevice IR Ops
499  */
500 static int cx23888_ir_irq_handler(struct v4l2_subdev *sd, u32 status,
501 				  bool *handled)
502 {
503 	struct cx23888_ir_state *state = to_state(sd);
504 	struct cx23885_dev *dev = state->dev;
505 	unsigned long flags;
506 
507 	u32 cntrl = cx23888_ir_read4(dev, CX23888_IR_CNTRL_REG);
508 	u32 irqen = cx23888_ir_read4(dev, CX23888_IR_IRQEN_REG);
509 	u32 stats = cx23888_ir_read4(dev, CX23888_IR_STATS_REG);
510 
511 	union cx23888_ir_fifo_rec rx_data[FIFO_RX_DEPTH];
512 	unsigned int i, j, k;
513 	u32 events, v;
514 	int tsr, rsr, rto, ror, tse, rse, rte, roe, kror;
515 
516 	tsr = stats & STATS_TSR; /* Tx FIFO Service Request */
517 	rsr = stats & STATS_RSR; /* Rx FIFO Service Request */
518 	rto = stats & STATS_RTO; /* Rx Pulse Width Timer Time Out */
519 	ror = stats & STATS_ROR; /* Rx FIFO Over Run */
520 
521 	tse = irqen & IRQEN_TSE; /* Tx FIFO Service Request IRQ Enable */
522 	rse = irqen & IRQEN_RSE; /* Rx FIFO Service Request IRQ Enable */
523 	rte = irqen & IRQEN_RTE; /* Rx Pulse Width Timer Time Out IRQ Enable */
524 	roe = irqen & IRQEN_ROE; /* Rx FIFO Over Run IRQ Enable */
525 
526 	*handled = false;
527 	v4l2_dbg(2, ir_888_debug, sd, "IRQ Status:  %s %s %s %s %s %s\n",
528 		 tsr ? "tsr" : "   ", rsr ? "rsr" : "   ",
529 		 rto ? "rto" : "   ", ror ? "ror" : "   ",
530 		 stats & STATS_TBY ? "tby" : "   ",
531 		 stats & STATS_RBY ? "rby" : "   ");
532 
533 	v4l2_dbg(2, ir_888_debug, sd, "IRQ Enables: %s %s %s %s\n",
534 		 tse ? "tse" : "   ", rse ? "rse" : "   ",
535 		 rte ? "rte" : "   ", roe ? "roe" : "   ");
536 
537 	/*
538 	 * Transmitter interrupt service
539 	 */
540 	if (tse && tsr) {
541 		/*
542 		 * TODO:
543 		 * Check the watermark threshold setting
544 		 * Pull FIFO_TX_DEPTH or FIFO_TX_DEPTH/2 entries from tx_kfifo
545 		 * Push the data to the hardware FIFO.
546 		 * If there was nothing more to send in the tx_kfifo, disable
547 		 *	the TSR IRQ and notify the v4l2_device.
548 		 * If there was something in the tx_kfifo, check the tx_kfifo
549 		 *      level and notify the v4l2_device, if it is low.
550 		 */
551 		/* For now, inhibit TSR interrupt until Tx is implemented */
552 		irqenable_tx(dev, 0);
553 		events = V4L2_SUBDEV_IR_TX_FIFO_SERVICE_REQ;
554 		v4l2_subdev_notify(sd, V4L2_SUBDEV_IR_TX_NOTIFY, &events);
555 		*handled = true;
556 	}
557 
558 	/*
559 	 * Receiver interrupt service
560 	 */
561 	kror = 0;
562 	if ((rse && rsr) || (rte && rto)) {
563 		/*
564 		 * Receive data on RSR to clear the STATS_RSR.
565 		 * Receive data on RTO, since we may not have yet hit the RSR
566 		 * watermark when we receive the RTO.
567 		 */
568 		for (i = 0, v = FIFO_RX_NDV;
569 		     (v & FIFO_RX_NDV) && !kror; i = 0) {
570 			for (j = 0;
571 			     (v & FIFO_RX_NDV) && j < FIFO_RX_DEPTH; j++) {
572 				v = cx23888_ir_read4(dev, CX23888_IR_FIFO_REG);
573 				rx_data[i].hw_fifo_data = v & ~FIFO_RX_NDV;
574 				i++;
575 			}
576 			if (i == 0)
577 				break;
578 			j = i * sizeof(union cx23888_ir_fifo_rec);
579 			k = kfifo_in_locked(&state->rx_kfifo,
580 				      (unsigned char *) rx_data, j,
581 				      &state->rx_kfifo_lock);
582 			if (k != j)
583 				kror++; /* rx_kfifo over run */
584 		}
585 		*handled = true;
586 	}
587 
588 	events = 0;
589 	v = 0;
590 	if (kror) {
591 		events |= V4L2_SUBDEV_IR_RX_SW_FIFO_OVERRUN;
592 		v4l2_err(sd, "IR receiver software FIFO overrun\n");
593 	}
594 	if (roe && ror) {
595 		/*
596 		 * The RX FIFO Enable (CNTRL_RFE) must be toggled to clear
597 		 * the Rx FIFO Over Run status (STATS_ROR)
598 		 */
599 		v |= CNTRL_RFE;
600 		events |= V4L2_SUBDEV_IR_RX_HW_FIFO_OVERRUN;
601 		v4l2_err(sd, "IR receiver hardware FIFO overrun\n");
602 	}
603 	if (rte && rto) {
604 		/*
605 		 * The IR Receiver Enable (CNTRL_RXE) must be toggled to clear
606 		 * the Rx Pulse Width Timer Time Out (STATS_RTO)
607 		 */
608 		v |= CNTRL_RXE;
609 		events |= V4L2_SUBDEV_IR_RX_END_OF_RX_DETECTED;
610 	}
611 	if (v) {
612 		/* Clear STATS_ROR & STATS_RTO as needed by resetting hardware */
613 		cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl & ~v);
614 		cx23888_ir_write4(dev, CX23888_IR_CNTRL_REG, cntrl);
615 		*handled = true;
616 	}
617 
618 	spin_lock_irqsave(&state->rx_kfifo_lock, flags);
619 	if (kfifo_len(&state->rx_kfifo) >= CX23888_IR_RX_KFIFO_SIZE / 2)
620 		events |= V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ;
621 	spin_unlock_irqrestore(&state->rx_kfifo_lock, flags);
622 
623 	if (events)
624 		v4l2_subdev_notify(sd, V4L2_SUBDEV_IR_RX_NOTIFY, &events);
625 	return 0;
626 }
627 
628 /* Receiver */
629 static int cx23888_ir_rx_read(struct v4l2_subdev *sd, u8 *buf, size_t count,
630 			      ssize_t *num)
631 {
632 	struct cx23888_ir_state *state = to_state(sd);
633 	bool invert = (bool) atomic_read(&state->rx_invert);
634 	u16 divider = (u16) atomic_read(&state->rxclk_divider);
635 
636 	unsigned int i, n;
637 	union cx23888_ir_fifo_rec *p;
638 	unsigned u, v, w;
639 
640 	n = count / sizeof(union cx23888_ir_fifo_rec)
641 		* sizeof(union cx23888_ir_fifo_rec);
642 	if (n == 0) {
643 		*num = 0;
644 		return 0;
645 	}
646 
647 	n = kfifo_out_locked(&state->rx_kfifo, buf, n, &state->rx_kfifo_lock);
648 
649 	n /= sizeof(union cx23888_ir_fifo_rec);
650 	*num = n * sizeof(union cx23888_ir_fifo_rec);
651 
652 	for (p = (union cx23888_ir_fifo_rec *) buf, i = 0; i < n; p++, i++) {
653 
654 		if ((p->hw_fifo_data & FIFO_RXTX_RTO) == FIFO_RXTX_RTO) {
655 			/* Assume RTO was because of no IR light input */
656 			u = 0;
657 			w = 1;
658 		} else {
659 			u = (p->hw_fifo_data & FIFO_RXTX_LVL) ? 1 : 0;
660 			if (invert)
661 				u = u ? 0 : 1;
662 			w = 0;
663 		}
664 
665 		v = (unsigned) pulse_width_count_to_ns(
666 				  (u16)(p->hw_fifo_data & FIFO_RXTX), divider) / 1000;
667 		if (v > IR_MAX_DURATION)
668 			v = IR_MAX_DURATION;
669 
670 		p->ir_core_data = (struct ir_raw_event)
671 			{ .pulse = u, .duration = v, .timeout = w };
672 
673 		v4l2_dbg(2, ir_888_debug, sd, "rx read: %10u ns  %s  %s\n",
674 			 v, u ? "mark" : "space", w ? "(timed out)" : "");
675 		if (w)
676 			v4l2_dbg(2, ir_888_debug, sd, "rx read: end of rx\n");
677 	}
678 	return 0;
679 }
680 
681 static int cx23888_ir_rx_g_parameters(struct v4l2_subdev *sd,
682 				      struct v4l2_subdev_ir_parameters *p)
683 {
684 	struct cx23888_ir_state *state = to_state(sd);
685 	mutex_lock(&state->rx_params_lock);
686 	memcpy(p, &state->rx_params, sizeof(struct v4l2_subdev_ir_parameters));
687 	mutex_unlock(&state->rx_params_lock);
688 	return 0;
689 }
690 
691 static int cx23888_ir_rx_shutdown(struct v4l2_subdev *sd)
692 {
693 	struct cx23888_ir_state *state = to_state(sd);
694 	struct cx23885_dev *dev = state->dev;
695 
696 	mutex_lock(&state->rx_params_lock);
697 
698 	/* Disable or slow down all IR Rx circuits and counters */
699 	irqenable_rx(dev, 0);
700 	control_rx_enable(dev, false);
701 	control_rx_demodulation_enable(dev, false);
702 	control_rx_s_edge_detection(dev, CNTRL_EDG_NONE);
703 	filter_rx_s_min_width(dev, 0);
704 	cx23888_ir_write4(dev, CX23888_IR_RXCLK_REG, RXCLK_RCD);
705 
706 	state->rx_params.shutdown = true;
707 
708 	mutex_unlock(&state->rx_params_lock);
709 	return 0;
710 }
711 
712 static int cx23888_ir_rx_s_parameters(struct v4l2_subdev *sd,
713 				      struct v4l2_subdev_ir_parameters *p)
714 {
715 	struct cx23888_ir_state *state = to_state(sd);
716 	struct cx23885_dev *dev = state->dev;
717 	struct v4l2_subdev_ir_parameters *o = &state->rx_params;
718 	u16 rxclk_divider;
719 
720 	if (p->shutdown)
721 		return cx23888_ir_rx_shutdown(sd);
722 
723 	if (p->mode != V4L2_SUBDEV_IR_MODE_PULSE_WIDTH)
724 		return -ENOSYS;
725 
726 	mutex_lock(&state->rx_params_lock);
727 
728 	o->shutdown = p->shutdown;
729 
730 	o->mode = p->mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
731 
732 	o->bytes_per_data_element = p->bytes_per_data_element
733 				  = sizeof(union cx23888_ir_fifo_rec);
734 
735 	/* Before we tweak the hardware, we have to disable the receiver */
736 	irqenable_rx(dev, 0);
737 	control_rx_enable(dev, false);
738 
739 	control_rx_demodulation_enable(dev, p->modulation);
740 	o->modulation = p->modulation;
741 
742 	if (p->modulation) {
743 		p->carrier_freq = rxclk_rx_s_carrier(dev, p->carrier_freq,
744 						     &rxclk_divider);
745 
746 		o->carrier_freq = p->carrier_freq;
747 
748 		o->duty_cycle = p->duty_cycle = 50;
749 
750 		control_rx_s_carrier_window(dev, p->carrier_freq,
751 					    &p->carrier_range_lower,
752 					    &p->carrier_range_upper);
753 		o->carrier_range_lower = p->carrier_range_lower;
754 		o->carrier_range_upper = p->carrier_range_upper;
755 
756 		p->max_pulse_width =
757 			(u32) pulse_width_count_to_ns(FIFO_RXTX, rxclk_divider);
758 	} else {
759 		p->max_pulse_width =
760 			    rxclk_rx_s_max_pulse_width(dev, p->max_pulse_width,
761 						       &rxclk_divider);
762 	}
763 	o->max_pulse_width = p->max_pulse_width;
764 	atomic_set(&state->rxclk_divider, rxclk_divider);
765 
766 	p->noise_filter_min_width =
767 			  filter_rx_s_min_width(dev, p->noise_filter_min_width);
768 	o->noise_filter_min_width = p->noise_filter_min_width;
769 
770 	p->resolution = clock_divider_to_resolution(rxclk_divider);
771 	o->resolution = p->resolution;
772 
773 	/* FIXME - make this dependent on resolution for better performance */
774 	control_rx_irq_watermark(dev, RX_FIFO_HALF_FULL);
775 
776 	control_rx_s_edge_detection(dev, CNTRL_EDG_BOTH);
777 
778 	o->invert_level = p->invert_level;
779 	atomic_set(&state->rx_invert, p->invert_level);
780 
781 	o->interrupt_enable = p->interrupt_enable;
782 	o->enable = p->enable;
783 	if (p->enable) {
784 		unsigned long flags;
785 
786 		spin_lock_irqsave(&state->rx_kfifo_lock, flags);
787 		kfifo_reset(&state->rx_kfifo);
788 		/* reset tx_fifo too if there is one... */
789 		spin_unlock_irqrestore(&state->rx_kfifo_lock, flags);
790 		if (p->interrupt_enable)
791 			irqenable_rx(dev, IRQEN_RSE | IRQEN_RTE | IRQEN_ROE);
792 		control_rx_enable(dev, p->enable);
793 	}
794 
795 	mutex_unlock(&state->rx_params_lock);
796 	return 0;
797 }
798 
799 /* Transmitter */
800 static int cx23888_ir_tx_write(struct v4l2_subdev *sd, u8 *buf, size_t count,
801 			       ssize_t *num)
802 {
803 	struct cx23888_ir_state *state = to_state(sd);
804 	struct cx23885_dev *dev = state->dev;
805 	/* For now enable the Tx FIFO Service interrupt & pretend we did work */
806 	irqenable_tx(dev, IRQEN_TSE);
807 	*num = count;
808 	return 0;
809 }
810 
811 static int cx23888_ir_tx_g_parameters(struct v4l2_subdev *sd,
812 				      struct v4l2_subdev_ir_parameters *p)
813 {
814 	struct cx23888_ir_state *state = to_state(sd);
815 	mutex_lock(&state->tx_params_lock);
816 	memcpy(p, &state->tx_params, sizeof(struct v4l2_subdev_ir_parameters));
817 	mutex_unlock(&state->tx_params_lock);
818 	return 0;
819 }
820 
821 static int cx23888_ir_tx_shutdown(struct v4l2_subdev *sd)
822 {
823 	struct cx23888_ir_state *state = to_state(sd);
824 	struct cx23885_dev *dev = state->dev;
825 
826 	mutex_lock(&state->tx_params_lock);
827 
828 	/* Disable or slow down all IR Tx circuits and counters */
829 	irqenable_tx(dev, 0);
830 	control_tx_enable(dev, false);
831 	control_tx_modulation_enable(dev, false);
832 	cx23888_ir_write4(dev, CX23888_IR_TXCLK_REG, TXCLK_TCD);
833 
834 	state->tx_params.shutdown = true;
835 
836 	mutex_unlock(&state->tx_params_lock);
837 	return 0;
838 }
839 
840 static int cx23888_ir_tx_s_parameters(struct v4l2_subdev *sd,
841 				      struct v4l2_subdev_ir_parameters *p)
842 {
843 	struct cx23888_ir_state *state = to_state(sd);
844 	struct cx23885_dev *dev = state->dev;
845 	struct v4l2_subdev_ir_parameters *o = &state->tx_params;
846 	u16 txclk_divider;
847 
848 	if (p->shutdown)
849 		return cx23888_ir_tx_shutdown(sd);
850 
851 	if (p->mode != V4L2_SUBDEV_IR_MODE_PULSE_WIDTH)
852 		return -ENOSYS;
853 
854 	mutex_lock(&state->tx_params_lock);
855 
856 	o->shutdown = p->shutdown;
857 
858 	o->mode = p->mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
859 
860 	o->bytes_per_data_element = p->bytes_per_data_element
861 				  = sizeof(union cx23888_ir_fifo_rec);
862 
863 	/* Before we tweak the hardware, we have to disable the transmitter */
864 	irqenable_tx(dev, 0);
865 	control_tx_enable(dev, false);
866 
867 	control_tx_modulation_enable(dev, p->modulation);
868 	o->modulation = p->modulation;
869 
870 	if (p->modulation) {
871 		p->carrier_freq = txclk_tx_s_carrier(dev, p->carrier_freq,
872 						     &txclk_divider);
873 		o->carrier_freq = p->carrier_freq;
874 
875 		p->duty_cycle = cduty_tx_s_duty_cycle(dev, p->duty_cycle);
876 		o->duty_cycle = p->duty_cycle;
877 
878 		p->max_pulse_width =
879 			(u32) pulse_width_count_to_ns(FIFO_RXTX, txclk_divider);
880 	} else {
881 		p->max_pulse_width =
882 			    txclk_tx_s_max_pulse_width(dev, p->max_pulse_width,
883 						       &txclk_divider);
884 	}
885 	o->max_pulse_width = p->max_pulse_width;
886 	atomic_set(&state->txclk_divider, txclk_divider);
887 
888 	p->resolution = clock_divider_to_resolution(txclk_divider);
889 	o->resolution = p->resolution;
890 
891 	/* FIXME - make this dependent on resolution for better performance */
892 	control_tx_irq_watermark(dev, TX_FIFO_HALF_EMPTY);
893 
894 	control_tx_polarity_invert(dev, p->invert_carrier_sense);
895 	o->invert_carrier_sense = p->invert_carrier_sense;
896 
897 	control_tx_level_invert(dev, p->invert_level);
898 	o->invert_level = p->invert_level;
899 
900 	o->interrupt_enable = p->interrupt_enable;
901 	o->enable = p->enable;
902 	if (p->enable) {
903 		if (p->interrupt_enable)
904 			irqenable_tx(dev, IRQEN_TSE);
905 		control_tx_enable(dev, p->enable);
906 	}
907 
908 	mutex_unlock(&state->tx_params_lock);
909 	return 0;
910 }
911 
912 
913 /*
914  * V4L2 Subdevice Core Ops
915  */
916 static int cx23888_ir_log_status(struct v4l2_subdev *sd)
917 {
918 	struct cx23888_ir_state *state = to_state(sd);
919 	struct cx23885_dev *dev = state->dev;
920 	char *s;
921 	int i, j;
922 
923 	u32 cntrl = cx23888_ir_read4(dev, CX23888_IR_CNTRL_REG);
924 	u32 txclk = cx23888_ir_read4(dev, CX23888_IR_TXCLK_REG) & TXCLK_TCD;
925 	u32 rxclk = cx23888_ir_read4(dev, CX23888_IR_RXCLK_REG) & RXCLK_RCD;
926 	u32 cduty = cx23888_ir_read4(dev, CX23888_IR_CDUTY_REG) & CDUTY_CDC;
927 	u32 stats = cx23888_ir_read4(dev, CX23888_IR_STATS_REG);
928 	u32 irqen = cx23888_ir_read4(dev, CX23888_IR_IRQEN_REG);
929 	u32 filtr = cx23888_ir_read4(dev, CX23888_IR_FILTR_REG) & FILTR_LPF;
930 
931 	v4l2_info(sd, "IR Receiver:\n");
932 	v4l2_info(sd, "\tEnabled:                           %s\n",
933 		  cntrl & CNTRL_RXE ? "yes" : "no");
934 	v4l2_info(sd, "\tDemodulation from a carrier:       %s\n",
935 		  cntrl & CNTRL_DMD ? "enabled" : "disabled");
936 	v4l2_info(sd, "\tFIFO:                              %s\n",
937 		  cntrl & CNTRL_RFE ? "enabled" : "disabled");
938 	switch (cntrl & CNTRL_EDG) {
939 	case CNTRL_EDG_NONE:
940 		s = "disabled";
941 		break;
942 	case CNTRL_EDG_FALL:
943 		s = "falling edge";
944 		break;
945 	case CNTRL_EDG_RISE:
946 		s = "rising edge";
947 		break;
948 	case CNTRL_EDG_BOTH:
949 		s = "rising & falling edges";
950 		break;
951 	default:
952 		s = "??? edge";
953 		break;
954 	}
955 	v4l2_info(sd, "\tPulse timers' start/stop trigger:  %s\n", s);
956 	v4l2_info(sd, "\tFIFO data on pulse timer overflow: %s\n",
957 		  cntrl & CNTRL_R ? "not loaded" : "overflow marker");
958 	v4l2_info(sd, "\tFIFO interrupt watermark:          %s\n",
959 		  cntrl & CNTRL_RIC ? "not empty" : "half full or greater");
960 	v4l2_info(sd, "\tLoopback mode:                     %s\n",
961 		  cntrl & CNTRL_LBM ? "loopback active" : "normal receive");
962 	if (cntrl & CNTRL_DMD) {
963 		v4l2_info(sd, "\tExpected carrier (16 clocks):      %u Hz\n",
964 			  clock_divider_to_carrier_freq(rxclk));
965 		switch (cntrl & CNTRL_WIN) {
966 		case CNTRL_WIN_3_3:
967 			i = 3;
968 			j = 3;
969 			break;
970 		case CNTRL_WIN_4_3:
971 			i = 4;
972 			j = 3;
973 			break;
974 		case CNTRL_WIN_3_4:
975 			i = 3;
976 			j = 4;
977 			break;
978 		case CNTRL_WIN_4_4:
979 			i = 4;
980 			j = 4;
981 			break;
982 		default:
983 			i = 0;
984 			j = 0;
985 			break;
986 		}
987 		v4l2_info(sd, "\tNext carrier edge window:	    16 clocks -%1d/+%1d, %u to %u Hz\n",
988 			  i, j,
989 			  clock_divider_to_freq(rxclk, 16 + j),
990 			  clock_divider_to_freq(rxclk, 16 - i));
991 	}
992 	v4l2_info(sd, "\tMax measurable pulse width:        %u us, %llu ns\n",
993 		  pulse_width_count_to_us(FIFO_RXTX, rxclk),
994 		  pulse_width_count_to_ns(FIFO_RXTX, rxclk));
995 	v4l2_info(sd, "\tLow pass filter:                   %s\n",
996 		  filtr ? "enabled" : "disabled");
997 	if (filtr)
998 		v4l2_info(sd, "\tMin acceptable pulse width (LPF):  %u us, %u ns\n",
999 			  lpf_count_to_us(filtr),
1000 			  lpf_count_to_ns(filtr));
1001 	v4l2_info(sd, "\tPulse width timer timed-out:       %s\n",
1002 		  stats & STATS_RTO ? "yes" : "no");
1003 	v4l2_info(sd, "\tPulse width timer time-out intr:   %s\n",
1004 		  irqen & IRQEN_RTE ? "enabled" : "disabled");
1005 	v4l2_info(sd, "\tFIFO overrun:                      %s\n",
1006 		  stats & STATS_ROR ? "yes" : "no");
1007 	v4l2_info(sd, "\tFIFO overrun interrupt:            %s\n",
1008 		  irqen & IRQEN_ROE ? "enabled" : "disabled");
1009 	v4l2_info(sd, "\tBusy:                              %s\n",
1010 		  stats & STATS_RBY ? "yes" : "no");
1011 	v4l2_info(sd, "\tFIFO service requested:            %s\n",
1012 		  stats & STATS_RSR ? "yes" : "no");
1013 	v4l2_info(sd, "\tFIFO service request interrupt:    %s\n",
1014 		  irqen & IRQEN_RSE ? "enabled" : "disabled");
1015 
1016 	v4l2_info(sd, "IR Transmitter:\n");
1017 	v4l2_info(sd, "\tEnabled:                           %s\n",
1018 		  cntrl & CNTRL_TXE ? "yes" : "no");
1019 	v4l2_info(sd, "\tModulation onto a carrier:         %s\n",
1020 		  cntrl & CNTRL_MOD ? "enabled" : "disabled");
1021 	v4l2_info(sd, "\tFIFO:                              %s\n",
1022 		  cntrl & CNTRL_TFE ? "enabled" : "disabled");
1023 	v4l2_info(sd, "\tFIFO interrupt watermark:          %s\n",
1024 		  cntrl & CNTRL_TIC ? "not empty" : "half full or less");
1025 	v4l2_info(sd, "\tOutput pin level inversion         %s\n",
1026 		  cntrl & CNTRL_IVO ? "yes" : "no");
1027 	v4l2_info(sd, "\tCarrier polarity:                  %s\n",
1028 		  cntrl & CNTRL_CPL ? "space:burst mark:noburst"
1029 				    : "space:noburst mark:burst");
1030 	if (cntrl & CNTRL_MOD) {
1031 		v4l2_info(sd, "\tCarrier (16 clocks):               %u Hz\n",
1032 			  clock_divider_to_carrier_freq(txclk));
1033 		v4l2_info(sd, "\tCarrier duty cycle:                %2u/16\n",
1034 			  cduty + 1);
1035 	}
1036 	v4l2_info(sd, "\tMax pulse width:                   %u us, %llu ns\n",
1037 		  pulse_width_count_to_us(FIFO_RXTX, txclk),
1038 		  pulse_width_count_to_ns(FIFO_RXTX, txclk));
1039 	v4l2_info(sd, "\tBusy:                              %s\n",
1040 		  stats & STATS_TBY ? "yes" : "no");
1041 	v4l2_info(sd, "\tFIFO service requested:            %s\n",
1042 		  stats & STATS_TSR ? "yes" : "no");
1043 	v4l2_info(sd, "\tFIFO service request interrupt:    %s\n",
1044 		  irqen & IRQEN_TSE ? "enabled" : "disabled");
1045 
1046 	return 0;
1047 }
1048 
1049 #ifdef CONFIG_VIDEO_ADV_DEBUG
1050 static int cx23888_ir_g_register(struct v4l2_subdev *sd,
1051 				 struct v4l2_dbg_register *reg)
1052 {
1053 	struct cx23888_ir_state *state = to_state(sd);
1054 	u32 addr = CX23888_IR_REG_BASE + (u32) reg->reg;
1055 
1056 	if ((addr & 0x3) != 0)
1057 		return -EINVAL;
1058 	if (addr < CX23888_IR_CNTRL_REG || addr > CX23888_IR_LEARN_REG)
1059 		return -EINVAL;
1060 	reg->size = 4;
1061 	reg->val = cx23888_ir_read4(state->dev, addr);
1062 	return 0;
1063 }
1064 
1065 static int cx23888_ir_s_register(struct v4l2_subdev *sd,
1066 				 const struct v4l2_dbg_register *reg)
1067 {
1068 	struct cx23888_ir_state *state = to_state(sd);
1069 	u32 addr = CX23888_IR_REG_BASE + (u32) reg->reg;
1070 
1071 	if ((addr & 0x3) != 0)
1072 		return -EINVAL;
1073 	if (addr < CX23888_IR_CNTRL_REG || addr > CX23888_IR_LEARN_REG)
1074 		return -EINVAL;
1075 	cx23888_ir_write4(state->dev, addr, reg->val);
1076 	return 0;
1077 }
1078 #endif
1079 
1080 static const struct v4l2_subdev_core_ops cx23888_ir_core_ops = {
1081 	.log_status = cx23888_ir_log_status,
1082 #ifdef CONFIG_VIDEO_ADV_DEBUG
1083 	.g_register = cx23888_ir_g_register,
1084 	.s_register = cx23888_ir_s_register,
1085 #endif
1086 	.interrupt_service_routine = cx23888_ir_irq_handler,
1087 };
1088 
1089 static const struct v4l2_subdev_ir_ops cx23888_ir_ir_ops = {
1090 	.rx_read = cx23888_ir_rx_read,
1091 	.rx_g_parameters = cx23888_ir_rx_g_parameters,
1092 	.rx_s_parameters = cx23888_ir_rx_s_parameters,
1093 
1094 	.tx_write = cx23888_ir_tx_write,
1095 	.tx_g_parameters = cx23888_ir_tx_g_parameters,
1096 	.tx_s_parameters = cx23888_ir_tx_s_parameters,
1097 };
1098 
1099 static const struct v4l2_subdev_ops cx23888_ir_controller_ops = {
1100 	.core = &cx23888_ir_core_ops,
1101 	.ir = &cx23888_ir_ir_ops,
1102 };
1103 
1104 static const struct v4l2_subdev_ir_parameters default_rx_params = {
1105 	.bytes_per_data_element = sizeof(union cx23888_ir_fifo_rec),
1106 	.mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH,
1107 
1108 	.enable = false,
1109 	.interrupt_enable = false,
1110 	.shutdown = true,
1111 
1112 	.modulation = true,
1113 	.carrier_freq = 36000, /* 36 kHz - RC-5, RC-6, and RC-6A carrier */
1114 
1115 	/* RC-5:    666,667 ns = 1/36 kHz * 32 cycles * 1 mark * 0.75 */
1116 	/* RC-6A:   333,333 ns = 1/36 kHz * 16 cycles * 1 mark * 0.75 */
1117 	.noise_filter_min_width = 333333, /* ns */
1118 	.carrier_range_lower = 35000,
1119 	.carrier_range_upper = 37000,
1120 	.invert_level = false,
1121 };
1122 
1123 static const struct v4l2_subdev_ir_parameters default_tx_params = {
1124 	.bytes_per_data_element = sizeof(union cx23888_ir_fifo_rec),
1125 	.mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH,
1126 
1127 	.enable = false,
1128 	.interrupt_enable = false,
1129 	.shutdown = true,
1130 
1131 	.modulation = true,
1132 	.carrier_freq = 36000, /* 36 kHz - RC-5 carrier */
1133 	.duty_cycle = 25,      /* 25 %   - RC-5 carrier */
1134 	.invert_level = false,
1135 	.invert_carrier_sense = false,
1136 };
1137 
1138 int cx23888_ir_probe(struct cx23885_dev *dev)
1139 {
1140 	struct cx23888_ir_state *state;
1141 	struct v4l2_subdev *sd;
1142 	struct v4l2_subdev_ir_parameters default_params;
1143 	int ret;
1144 
1145 	state = kzalloc(sizeof(struct cx23888_ir_state), GFP_KERNEL);
1146 	if (state == NULL)
1147 		return -ENOMEM;
1148 
1149 	spin_lock_init(&state->rx_kfifo_lock);
1150 	if (kfifo_alloc(&state->rx_kfifo, CX23888_IR_RX_KFIFO_SIZE,
1151 			GFP_KERNEL)) {
1152 		kfree(state);
1153 		return -ENOMEM;
1154 	}
1155 
1156 	state->dev = dev;
1157 	sd = &state->sd;
1158 
1159 	v4l2_subdev_init(sd, &cx23888_ir_controller_ops);
1160 	v4l2_set_subdevdata(sd, state);
1161 	/* FIXME - fix the formatting of dev->v4l2_dev.name and use it */
1162 	snprintf(sd->name, sizeof(sd->name), "%s/888-ir", dev->name);
1163 	sd->grp_id = CX23885_HW_888_IR;
1164 
1165 	ret = v4l2_device_register_subdev(&dev->v4l2_dev, sd);
1166 	if (ret == 0) {
1167 		/*
1168 		 * Ensure no interrupts arrive from '888 specific conditions,
1169 		 * since we ignore them in this driver to have commonality with
1170 		 * similar IR controller cores.
1171 		 */
1172 		cx23888_ir_write4(dev, CX23888_IR_IRQEN_REG, 0);
1173 
1174 		mutex_init(&state->rx_params_lock);
1175 		default_params = default_rx_params;
1176 		v4l2_subdev_call(sd, ir, rx_s_parameters, &default_params);
1177 
1178 		mutex_init(&state->tx_params_lock);
1179 		default_params = default_tx_params;
1180 		v4l2_subdev_call(sd, ir, tx_s_parameters, &default_params);
1181 	} else {
1182 		kfifo_free(&state->rx_kfifo);
1183 	}
1184 	return ret;
1185 }
1186 
1187 int cx23888_ir_remove(struct cx23885_dev *dev)
1188 {
1189 	struct v4l2_subdev *sd;
1190 	struct cx23888_ir_state *state;
1191 
1192 	sd = cx23885_find_hw(dev, CX23885_HW_888_IR);
1193 	if (sd == NULL)
1194 		return -ENODEV;
1195 
1196 	cx23888_ir_rx_shutdown(sd);
1197 	cx23888_ir_tx_shutdown(sd);
1198 
1199 	state = to_state(sd);
1200 	v4l2_device_unregister_subdev(sd);
1201 	kfifo_free(&state->rx_kfifo);
1202 	kfree(state);
1203 	/* Nothing more to free() as state held the actual v4l2_subdev object */
1204 	return 0;
1205 }
1206