1 /*
2 * Frame Interval Monitor.
3 *
4 * Copyright (c) 2016 Mentor Graphics Inc.
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
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11 #include <linux/delay.h>
12 #include <linux/irq.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <media/v4l2-ctrls.h>
18 #include <media/v4l2-subdev.h>
19 #include <media/imx.h>
20 #include "imx-media.h"
21
22 enum {
23 FIM_CL_ENABLE = 0,
24 FIM_CL_NUM,
25 FIM_CL_TOLERANCE_MIN,
26 FIM_CL_TOLERANCE_MAX,
27 FIM_CL_NUM_SKIP,
28 FIM_NUM_CONTROLS,
29 };
30
31 enum {
32 FIM_CL_ICAP_EDGE = 0,
33 FIM_CL_ICAP_CHANNEL,
34 FIM_NUM_ICAP_CONTROLS,
35 };
36
37 #define FIM_CL_ENABLE_DEF 0 /* FIM disabled by default */
38 #define FIM_CL_NUM_DEF 8 /* average 8 frames */
39 #define FIM_CL_NUM_SKIP_DEF 2 /* skip 2 frames after restart */
40 #define FIM_CL_TOLERANCE_MIN_DEF 50 /* usec */
41 #define FIM_CL_TOLERANCE_MAX_DEF 0 /* no max tolerance (unbounded) */
42
43 struct imx_media_fim {
44 struct imx_media_dev *md;
45
46 /* the owning subdev of this fim instance */
47 struct v4l2_subdev *sd;
48
49 /* FIM's control handler */
50 struct v4l2_ctrl_handler ctrl_handler;
51
52 /* control clusters */
53 struct v4l2_ctrl *ctrl[FIM_NUM_CONTROLS];
54 struct v4l2_ctrl *icap_ctrl[FIM_NUM_ICAP_CONTROLS];
55
56 spinlock_t lock; /* protect control values */
57
58 /* current control values */
59 bool enabled;
60 int num_avg;
61 int num_skip;
62 unsigned long tolerance_min; /* usec */
63 unsigned long tolerance_max; /* usec */
64 /* input capture method of measuring FI */
65 int icap_channel;
66 int icap_flags;
67
68 int counter;
69 ktime_t last_ts;
70 unsigned long sum; /* usec */
71 unsigned long nominal; /* usec */
72
73 struct completion icap_first_event;
74 bool stream_on;
75 };
76
77 #define icap_enabled(fim) ((fim)->icap_flags != IRQ_TYPE_NONE)
78
update_fim_nominal(struct imx_media_fim * fim,const struct v4l2_fract * fi)79 static void update_fim_nominal(struct imx_media_fim *fim,
80 const struct v4l2_fract *fi)
81 {
82 if (fi->denominator == 0) {
83 dev_dbg(fim->sd->dev, "no frame interval, FIM disabled\n");
84 fim->enabled = false;
85 return;
86 }
87
88 fim->nominal = DIV_ROUND_CLOSEST_ULL(1000000ULL * (u64)fi->numerator,
89 fi->denominator);
90
91 dev_dbg(fim->sd->dev, "FI=%lu usec\n", fim->nominal);
92 }
93
reset_fim(struct imx_media_fim * fim,bool curval)94 static void reset_fim(struct imx_media_fim *fim, bool curval)
95 {
96 struct v4l2_ctrl *icap_chan = fim->icap_ctrl[FIM_CL_ICAP_CHANNEL];
97 struct v4l2_ctrl *icap_edge = fim->icap_ctrl[FIM_CL_ICAP_EDGE];
98 struct v4l2_ctrl *en = fim->ctrl[FIM_CL_ENABLE];
99 struct v4l2_ctrl *num = fim->ctrl[FIM_CL_NUM];
100 struct v4l2_ctrl *skip = fim->ctrl[FIM_CL_NUM_SKIP];
101 struct v4l2_ctrl *tol_min = fim->ctrl[FIM_CL_TOLERANCE_MIN];
102 struct v4l2_ctrl *tol_max = fim->ctrl[FIM_CL_TOLERANCE_MAX];
103
104 if (curval) {
105 fim->enabled = en->cur.val;
106 fim->icap_flags = icap_edge->cur.val;
107 fim->icap_channel = icap_chan->cur.val;
108 fim->num_avg = num->cur.val;
109 fim->num_skip = skip->cur.val;
110 fim->tolerance_min = tol_min->cur.val;
111 fim->tolerance_max = tol_max->cur.val;
112 } else {
113 fim->enabled = en->val;
114 fim->icap_flags = icap_edge->val;
115 fim->icap_channel = icap_chan->val;
116 fim->num_avg = num->val;
117 fim->num_skip = skip->val;
118 fim->tolerance_min = tol_min->val;
119 fim->tolerance_max = tol_max->val;
120 }
121
122 /* disable tolerance range if max <= min */
123 if (fim->tolerance_max <= fim->tolerance_min)
124 fim->tolerance_max = 0;
125
126 /* num_skip must be >= 1 if input capture not used */
127 if (!icap_enabled(fim))
128 fim->num_skip = max_t(int, fim->num_skip, 1);
129
130 fim->counter = -fim->num_skip;
131 fim->sum = 0;
132 }
133
send_fim_event(struct imx_media_fim * fim,unsigned long error)134 static void send_fim_event(struct imx_media_fim *fim, unsigned long error)
135 {
136 static const struct v4l2_event ev = {
137 .type = V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR,
138 };
139
140 v4l2_subdev_notify_event(fim->sd, &ev);
141 }
142
143 /*
144 * Monitor an averaged frame interval. If the average deviates too much
145 * from the nominal frame rate, send the frame interval error event. The
146 * frame intervals are averaged in order to quiet noise from
147 * (presumably random) interrupt latency.
148 */
frame_interval_monitor(struct imx_media_fim * fim,ktime_t timestamp)149 static void frame_interval_monitor(struct imx_media_fim *fim,
150 ktime_t timestamp)
151 {
152 long long interval, error;
153 unsigned long error_avg;
154 bool send_event = false;
155
156 if (!fim->enabled || ++fim->counter <= 0)
157 goto out_update_ts;
158
159 /* max error is less than l00µs, so use 32-bit division or fail */
160 interval = ktime_to_ns(ktime_sub(timestamp, fim->last_ts));
161 error = abs(interval - NSEC_PER_USEC * (u64)fim->nominal);
162 if (error > U32_MAX)
163 error = U32_MAX;
164 else
165 error = abs((u32)error / NSEC_PER_USEC);
166
167 if (fim->tolerance_max && error >= fim->tolerance_max) {
168 dev_dbg(fim->sd->dev,
169 "FIM: %llu ignored, out of tolerance bounds\n",
170 error);
171 fim->counter--;
172 goto out_update_ts;
173 }
174
175 fim->sum += error;
176
177 if (fim->counter == fim->num_avg) {
178 error_avg = DIV_ROUND_CLOSEST(fim->sum, fim->num_avg);
179
180 if (error_avg > fim->tolerance_min)
181 send_event = true;
182
183 dev_dbg(fim->sd->dev, "FIM: error: %lu usec%s\n",
184 error_avg, send_event ? " (!!!)" : "");
185
186 fim->counter = 0;
187 fim->sum = 0;
188 }
189
190 out_update_ts:
191 fim->last_ts = timestamp;
192 if (send_event)
193 send_fim_event(fim, error_avg);
194 }
195
196 #ifdef CONFIG_IMX_GPT_ICAP
197 /*
198 * Input Capture method of measuring frame intervals. Not subject
199 * to interrupt latency.
200 */
fim_input_capture_handler(int channel,void * dev_id,ktime_t timestamp)201 static void fim_input_capture_handler(int channel, void *dev_id,
202 ktime_t timestamp)
203 {
204 struct imx_media_fim *fim = dev_id;
205 unsigned long flags;
206
207 spin_lock_irqsave(&fim->lock, flags);
208
209 frame_interval_monitor(fim, timestamp);
210
211 if (!completion_done(&fim->icap_first_event))
212 complete(&fim->icap_first_event);
213
214 spin_unlock_irqrestore(&fim->lock, flags);
215 }
216
fim_request_input_capture(struct imx_media_fim * fim)217 static int fim_request_input_capture(struct imx_media_fim *fim)
218 {
219 init_completion(&fim->icap_first_event);
220
221 return mxc_request_input_capture(fim->icap_channel,
222 fim_input_capture_handler,
223 fim->icap_flags, fim);
224 }
225
fim_free_input_capture(struct imx_media_fim * fim)226 static void fim_free_input_capture(struct imx_media_fim *fim)
227 {
228 mxc_free_input_capture(fim->icap_channel, fim);
229 }
230
231 #else /* CONFIG_IMX_GPT_ICAP */
232
fim_request_input_capture(struct imx_media_fim * fim)233 static int fim_request_input_capture(struct imx_media_fim *fim)
234 {
235 return 0;
236 }
237
fim_free_input_capture(struct imx_media_fim * fim)238 static void fim_free_input_capture(struct imx_media_fim *fim)
239 {
240 }
241
242 #endif /* CONFIG_IMX_GPT_ICAP */
243
244 /*
245 * In case we are monitoring the first frame interval after streamon
246 * (when fim->num_skip = 0), we need a valid fim->last_ts before we
247 * can begin. This only applies to the input capture method. It is not
248 * possible to accurately measure the first FI after streamon using the
249 * EOF method, so fim->num_skip minimum is set to 1 in that case, so this
250 * function is a noop when the EOF method is used.
251 */
fim_acquire_first_ts(struct imx_media_fim * fim)252 static void fim_acquire_first_ts(struct imx_media_fim *fim)
253 {
254 unsigned long ret;
255
256 if (!fim->enabled || fim->num_skip > 0)
257 return;
258
259 ret = wait_for_completion_timeout(
260 &fim->icap_first_event,
261 msecs_to_jiffies(IMX_MEDIA_EOF_TIMEOUT));
262 if (ret == 0)
263 v4l2_warn(fim->sd, "wait first icap event timeout\n");
264 }
265
266 /* FIM Controls */
fim_s_ctrl(struct v4l2_ctrl * ctrl)267 static int fim_s_ctrl(struct v4l2_ctrl *ctrl)
268 {
269 struct imx_media_fim *fim = container_of(ctrl->handler,
270 struct imx_media_fim,
271 ctrl_handler);
272 unsigned long flags;
273 int ret = 0;
274
275 spin_lock_irqsave(&fim->lock, flags);
276
277 switch (ctrl->id) {
278 case V4L2_CID_IMX_FIM_ENABLE:
279 break;
280 case V4L2_CID_IMX_FIM_ICAP_EDGE:
281 if (fim->stream_on)
282 ret = -EBUSY;
283 break;
284 default:
285 ret = -EINVAL;
286 }
287
288 if (!ret)
289 reset_fim(fim, false);
290
291 spin_unlock_irqrestore(&fim->lock, flags);
292 return ret;
293 }
294
295 static const struct v4l2_ctrl_ops fim_ctrl_ops = {
296 .s_ctrl = fim_s_ctrl,
297 };
298
299 static const struct v4l2_ctrl_config fim_ctrl[] = {
300 [FIM_CL_ENABLE] = {
301 .ops = &fim_ctrl_ops,
302 .id = V4L2_CID_IMX_FIM_ENABLE,
303 .name = "FIM Enable",
304 .type = V4L2_CTRL_TYPE_BOOLEAN,
305 .def = FIM_CL_ENABLE_DEF,
306 .min = 0,
307 .max = 1,
308 .step = 1,
309 },
310 [FIM_CL_NUM] = {
311 .ops = &fim_ctrl_ops,
312 .id = V4L2_CID_IMX_FIM_NUM,
313 .name = "FIM Num Average",
314 .type = V4L2_CTRL_TYPE_INTEGER,
315 .def = FIM_CL_NUM_DEF,
316 .min = 1, /* no averaging */
317 .max = 64, /* average 64 frames */
318 .step = 1,
319 },
320 [FIM_CL_TOLERANCE_MIN] = {
321 .ops = &fim_ctrl_ops,
322 .id = V4L2_CID_IMX_FIM_TOLERANCE_MIN,
323 .name = "FIM Tolerance Min",
324 .type = V4L2_CTRL_TYPE_INTEGER,
325 .def = FIM_CL_TOLERANCE_MIN_DEF,
326 .min = 2,
327 .max = 200,
328 .step = 1,
329 },
330 [FIM_CL_TOLERANCE_MAX] = {
331 .ops = &fim_ctrl_ops,
332 .id = V4L2_CID_IMX_FIM_TOLERANCE_MAX,
333 .name = "FIM Tolerance Max",
334 .type = V4L2_CTRL_TYPE_INTEGER,
335 .def = FIM_CL_TOLERANCE_MAX_DEF,
336 .min = 0,
337 .max = 500,
338 .step = 1,
339 },
340 [FIM_CL_NUM_SKIP] = {
341 .ops = &fim_ctrl_ops,
342 .id = V4L2_CID_IMX_FIM_NUM_SKIP,
343 .name = "FIM Num Skip",
344 .type = V4L2_CTRL_TYPE_INTEGER,
345 .def = FIM_CL_NUM_SKIP_DEF,
346 .min = 0, /* skip no frames */
347 .max = 256, /* skip 256 frames */
348 .step = 1,
349 },
350 };
351
352 static const struct v4l2_ctrl_config fim_icap_ctrl[] = {
353 [FIM_CL_ICAP_EDGE] = {
354 .ops = &fim_ctrl_ops,
355 .id = V4L2_CID_IMX_FIM_ICAP_EDGE,
356 .name = "FIM Input Capture Edge",
357 .type = V4L2_CTRL_TYPE_INTEGER,
358 .def = IRQ_TYPE_NONE, /* input capture disabled by default */
359 .min = IRQ_TYPE_NONE,
360 .max = IRQ_TYPE_EDGE_BOTH,
361 .step = 1,
362 },
363 [FIM_CL_ICAP_CHANNEL] = {
364 .ops = &fim_ctrl_ops,
365 .id = V4L2_CID_IMX_FIM_ICAP_CHANNEL,
366 .name = "FIM Input Capture Channel",
367 .type = V4L2_CTRL_TYPE_INTEGER,
368 .def = 0,
369 .min = 0,
370 .max = 1,
371 .step = 1,
372 },
373 };
374
init_fim_controls(struct imx_media_fim * fim)375 static int init_fim_controls(struct imx_media_fim *fim)
376 {
377 struct v4l2_ctrl_handler *hdlr = &fim->ctrl_handler;
378 int i, ret;
379
380 v4l2_ctrl_handler_init(hdlr, FIM_NUM_CONTROLS + FIM_NUM_ICAP_CONTROLS);
381
382 for (i = 0; i < FIM_NUM_CONTROLS; i++)
383 fim->ctrl[i] = v4l2_ctrl_new_custom(hdlr,
384 &fim_ctrl[i],
385 NULL);
386 for (i = 0; i < FIM_NUM_ICAP_CONTROLS; i++)
387 fim->icap_ctrl[i] = v4l2_ctrl_new_custom(hdlr,
388 &fim_icap_ctrl[i],
389 NULL);
390 if (hdlr->error) {
391 ret = hdlr->error;
392 goto err_free;
393 }
394
395 v4l2_ctrl_cluster(FIM_NUM_CONTROLS, fim->ctrl);
396 v4l2_ctrl_cluster(FIM_NUM_ICAP_CONTROLS, fim->icap_ctrl);
397
398 return 0;
399 err_free:
400 v4l2_ctrl_handler_free(hdlr);
401 return ret;
402 }
403
404 /*
405 * Monitor frame intervals via EOF interrupt. This method is
406 * subject to uncertainty errors introduced by interrupt latency.
407 *
408 * This is a noop if the Input Capture method is being used, since
409 * the frame_interval_monitor() is called by the input capture event
410 * callback handler in that case.
411 */
imx_media_fim_eof_monitor(struct imx_media_fim * fim,ktime_t timestamp)412 void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp)
413 {
414 unsigned long flags;
415
416 spin_lock_irqsave(&fim->lock, flags);
417
418 if (!icap_enabled(fim))
419 frame_interval_monitor(fim, timestamp);
420
421 spin_unlock_irqrestore(&fim->lock, flags);
422 }
423 EXPORT_SYMBOL_GPL(imx_media_fim_eof_monitor);
424
425 /* Called by the subdev in its s_stream callback */
imx_media_fim_set_stream(struct imx_media_fim * fim,const struct v4l2_fract * fi,bool on)426 int imx_media_fim_set_stream(struct imx_media_fim *fim,
427 const struct v4l2_fract *fi,
428 bool on)
429 {
430 unsigned long flags;
431 int ret = 0;
432
433 v4l2_ctrl_lock(fim->ctrl[FIM_CL_ENABLE]);
434
435 if (fim->stream_on == on)
436 goto out;
437
438 if (on) {
439 spin_lock_irqsave(&fim->lock, flags);
440 reset_fim(fim, true);
441 update_fim_nominal(fim, fi);
442 spin_unlock_irqrestore(&fim->lock, flags);
443
444 if (icap_enabled(fim)) {
445 ret = fim_request_input_capture(fim);
446 if (ret)
447 goto out;
448 fim_acquire_first_ts(fim);
449 }
450 } else {
451 if (icap_enabled(fim))
452 fim_free_input_capture(fim);
453 }
454
455 fim->stream_on = on;
456 out:
457 v4l2_ctrl_unlock(fim->ctrl[FIM_CL_ENABLE]);
458 return ret;
459 }
460 EXPORT_SYMBOL_GPL(imx_media_fim_set_stream);
461
imx_media_fim_add_controls(struct imx_media_fim * fim)462 int imx_media_fim_add_controls(struct imx_media_fim *fim)
463 {
464 /* add the FIM controls to the calling subdev ctrl handler */
465 return v4l2_ctrl_add_handler(fim->sd->ctrl_handler,
466 &fim->ctrl_handler, NULL);
467 }
468 EXPORT_SYMBOL_GPL(imx_media_fim_add_controls);
469
470 /* Called by the subdev in its subdev registered callback */
imx_media_fim_init(struct v4l2_subdev * sd)471 struct imx_media_fim *imx_media_fim_init(struct v4l2_subdev *sd)
472 {
473 struct imx_media_fim *fim;
474 int ret;
475
476 fim = devm_kzalloc(sd->dev, sizeof(*fim), GFP_KERNEL);
477 if (!fim)
478 return ERR_PTR(-ENOMEM);
479
480 /* get media device */
481 fim->md = dev_get_drvdata(sd->v4l2_dev->dev);
482 fim->sd = sd;
483
484 spin_lock_init(&fim->lock);
485
486 ret = init_fim_controls(fim);
487 if (ret)
488 return ERR_PTR(ret);
489
490 return fim;
491 }
492 EXPORT_SYMBOL_GPL(imx_media_fim_init);
493
imx_media_fim_free(struct imx_media_fim * fim)494 void imx_media_fim_free(struct imx_media_fim *fim)
495 {
496 v4l2_ctrl_handler_free(&fim->ctrl_handler);
497 }
498 EXPORT_SYMBOL_GPL(imx_media_fim_free);
499