drivers/staging/media/imx/imx-media-fim.c

   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         struct timespec   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
  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
  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
 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  */
 149 static void frame_interval_monitor(struct imx_media_fim *fim,
 150                                    struct timespec *ts)
 151 {
 152         unsigned long interval, error, error_avg;
 153         bool send_event = false;
 154         struct timespec diff;
 155
 156         if (!fim->enabled || ++fim->counter <= 0)
 157                 goto out_update_ts;
 158
 159         diff = timespec_sub(*ts, fim->last_ts);
 160         interval = diff.tv_sec * 1000 * 1000 + diff.tv_nsec / 1000;
 161         error = abs(interval - fim->nominal);
 162
 163         if (fim->tolerance_max && error >= fim->tolerance_max) {
 164                 dev_dbg(fim->sd->dev,
 165                         "FIM: %lu ignored, out of tolerance bounds\n",
 166                         error);
 167                 fim->counter--;
 168                 goto out_update_ts;
 169         }
 170
 171         fim->sum += error;
 172
 173         if (fim->counter == fim->num_avg) {
 174                 error_avg = DIV_ROUND_CLOSEST(fim->sum, fim->num_avg);
 175
 176                 if (error_avg > fim->tolerance_min)
 177                         send_event = true;
 178
 179                 dev_dbg(fim->sd->dev, "FIM: error: %lu usec%s\n",
 180                         error_avg, send_event ? " (!!!)" : "");
 181
 182                 fim->counter = 0;
 183                 fim->sum = 0;
 184         }
 185
 186 out_update_ts:
 187         fim->last_ts = *ts;
 188         if (send_event)
 189                 send_fim_event(fim, error_avg);
 190 }
 191
 192 #ifdef CONFIG_IMX_GPT_ICAP
 193 /*
 194  * Input Capture method of measuring frame intervals. Not subject
 195  * to interrupt latency.
 196  */
 197 static void fim_input_capture_handler(int channel, void *dev_id,
 198                                       struct timespec *ts)
 199 {
 200         struct imx_media_fim *fim = dev_id;
 201         unsigned long flags;
 202
 203         spin_lock_irqsave(&fim->lock, flags);
 204
 205         frame_interval_monitor(fim, ts);
 206
 207         if (!completion_done(&fim->icap_first_event))
 208                 complete(&fim->icap_first_event);
 209
 210         spin_unlock_irqrestore(&fim->lock, flags);
 211 }
 212
 213 static int fim_request_input_capture(struct imx_media_fim *fim)
 214 {
 215         init_completion(&fim->icap_first_event);
 216
 217         return mxc_request_input_capture(fim->icap_channel,
 218                                          fim_input_capture_handler,
 219                                          fim->icap_flags, fim);
 220 }
 221
 222 static void fim_free_input_capture(struct imx_media_fim *fim)
 223 {
 224         mxc_free_input_capture(fim->icap_channel, fim);
 225 }
 226
 227 #else /* CONFIG_IMX_GPT_ICAP */
 228
 229 static int fim_request_input_capture(struct imx_media_fim *fim)
 230 {
 231         return 0;
 232 }
 233
 234 static void fim_free_input_capture(struct imx_media_fim *fim)
 235 {
 236 }
 237
 238 #endif /* CONFIG_IMX_GPT_ICAP */
 239
 240 /*
 241  * In case we are monitoring the first frame interval after streamon
 242  * (when fim->num_skip = 0), we need a valid fim->last_ts before we
 243  * can begin. This only applies to the input capture method. It is not
 244  * possible to accurately measure the first FI after streamon using the
 245  * EOF method, so fim->num_skip minimum is set to 1 in that case, so this
 246  * function is a noop when the EOF method is used.
 247  */
 248 static void fim_acquire_first_ts(struct imx_media_fim *fim)
 249 {
 250         unsigned long ret;
 251
 252         if (!fim->enabled || fim->num_skip > 0)
 253                 return;
 254
 255         ret = wait_for_completion_timeout(
 256                 &fim->icap_first_event,
 257                 msecs_to_jiffies(IMX_MEDIA_EOF_TIMEOUT));
 258         if (ret == 0)
 259                 v4l2_warn(fim->sd, "wait first icap event timeout\n");
 260 }
 261
 262 /* FIM Controls */
 263 static int fim_s_ctrl(struct v4l2_ctrl *ctrl)
 264 {
 265         struct imx_media_fim *fim = container_of(ctrl->handler,
 266                                                  struct imx_media_fim,
 267                                                  ctrl_handler);
 268         unsigned long flags;
 269         int ret = 0;
 270
 271         spin_lock_irqsave(&fim->lock, flags);
 272
 273         switch (ctrl->id) {
 274         case V4L2_CID_IMX_FIM_ENABLE:
 275                 break;
 276         case V4L2_CID_IMX_FIM_ICAP_EDGE:
 277                 if (fim->stream_on)
 278                         ret = -EBUSY;
 279                 break;
 280         default:
 281                 ret = -EINVAL;
 282         }
 283
 284         if (!ret)
 285                 reset_fim(fim, false);
 286
 287         spin_unlock_irqrestore(&fim->lock, flags);
 288         return ret;
 289 }
 290
 291 static const struct v4l2_ctrl_ops fim_ctrl_ops = {
 292         .s_ctrl = fim_s_ctrl,
 293 };
 294
 295 static const struct v4l2_ctrl_config fim_ctrl[] = {
 296         [FIM_CL_ENABLE] = {
 297                 .ops = &fim_ctrl_ops,
 298                 .id = V4L2_CID_IMX_FIM_ENABLE,
 299                 .name = "FIM Enable",
 300                 .type = V4L2_CTRL_TYPE_BOOLEAN,
 301                 .def = FIM_CL_ENABLE_DEF,
 302                 .min = 0,
 303                 .max = 1,
 304                 .step = 1,
 305         },
 306         [FIM_CL_NUM] = {
 307                 .ops = &fim_ctrl_ops,
 308                 .id = V4L2_CID_IMX_FIM_NUM,
 309                 .name = "FIM Num Average",
 310                 .type = V4L2_CTRL_TYPE_INTEGER,
 311                 .def = FIM_CL_NUM_DEF,
 312                 .min =  1, /* no averaging */
 313                 .max = 64, /* average 64 frames */
 314                 .step = 1,
 315         },
 316         [FIM_CL_TOLERANCE_MIN] = {
 317                 .ops = &fim_ctrl_ops,
 318                 .id = V4L2_CID_IMX_FIM_TOLERANCE_MIN,
 319                 .name = "FIM Tolerance Min",
 320                 .type = V4L2_CTRL_TYPE_INTEGER,
 321                 .def = FIM_CL_TOLERANCE_MIN_DEF,
 322                 .min =    2,
 323                 .max =  200,
 324                 .step =   1,
 325         },
 326         [FIM_CL_TOLERANCE_MAX] = {
 327                 .ops = &fim_ctrl_ops,
 328                 .id = V4L2_CID_IMX_FIM_TOLERANCE_MAX,
 329                 .name = "FIM Tolerance Max",
 330                 .type = V4L2_CTRL_TYPE_INTEGER,
 331                 .def = FIM_CL_TOLERANCE_MAX_DEF,
 332                 .min =    0,
 333                 .max =  500,
 334                 .step =   1,
 335         },
 336         [FIM_CL_NUM_SKIP] = {
 337                 .ops = &fim_ctrl_ops,
 338                 .id = V4L2_CID_IMX_FIM_NUM_SKIP,
 339                 .name = "FIM Num Skip",
 340                 .type = V4L2_CTRL_TYPE_INTEGER,
 341                 .def = FIM_CL_NUM_SKIP_DEF,
 342                 .min =   0, /* skip no frames */
 343                 .max = 256, /* skip 256 frames */
 344                 .step =  1,
 345         },
 346 };
 347
 348 static const struct v4l2_ctrl_config fim_icap_ctrl[] = {
 349         [FIM_CL_ICAP_EDGE] = {
 350                 .ops = &fim_ctrl_ops,
 351                 .id = V4L2_CID_IMX_FIM_ICAP_EDGE,
 352                 .name = "FIM Input Capture Edge",
 353                 .type = V4L2_CTRL_TYPE_INTEGER,
 354                 .def =  IRQ_TYPE_NONE, /* input capture disabled by default */
 355                 .min =  IRQ_TYPE_NONE,
 356                 .max =  IRQ_TYPE_EDGE_BOTH,
 357                 .step = 1,
 358         },
 359         [FIM_CL_ICAP_CHANNEL] = {
 360                 .ops = &fim_ctrl_ops,
 361                 .id = V4L2_CID_IMX_FIM_ICAP_CHANNEL,
 362                 .name = "FIM Input Capture Channel",
 363                 .type = V4L2_CTRL_TYPE_INTEGER,
 364                 .def =  0,
 365                 .min =  0,
 366                 .max =  1,
 367                 .step = 1,
 368         },
 369 };
 370
 371 static int init_fim_controls(struct imx_media_fim *fim)
 372 {
 373         struct v4l2_ctrl_handler *hdlr = &fim->ctrl_handler;
 374         int i, ret;
 375
 376         v4l2_ctrl_handler_init(hdlr, FIM_NUM_CONTROLS + FIM_NUM_ICAP_CONTROLS);
 377
 378         for (i = 0; i < FIM_NUM_CONTROLS; i++)
 379                 fim->ctrl[i] = v4l2_ctrl_new_custom(hdlr,
 380                                                     &fim_ctrl[i],
 381                                                     NULL);
 382         for (i = 0; i < FIM_NUM_ICAP_CONTROLS; i++)
 383                 fim->icap_ctrl[i] = v4l2_ctrl_new_custom(hdlr,
 384                                                          &fim_icap_ctrl[i],
 385                                                          NULL);
 386         if (hdlr->error) {
 387                 ret = hdlr->error;
 388                 goto err_free;
 389         }
 390
 391         v4l2_ctrl_cluster(FIM_NUM_CONTROLS, fim->ctrl);
 392         v4l2_ctrl_cluster(FIM_NUM_ICAP_CONTROLS, fim->icap_ctrl);
 393
 394         return 0;
 395 err_free:
 396         v4l2_ctrl_handler_free(hdlr);
 397         return ret;
 398 }
 399
 400 /*
 401  * Monitor frame intervals via EOF interrupt. This method is
 402  * subject to uncertainty errors introduced by interrupt latency.
 403  *
 404  * This is a noop if the Input Capture method is being used, since
 405  * the frame_interval_monitor() is called by the input capture event
 406  * callback handler in that case.
 407  */
 408 void imx_media_fim_eof_monitor(struct imx_media_fim *fim, struct timespec *ts)
 409 {
 410         unsigned long flags;
 411
 412         spin_lock_irqsave(&fim->lock, flags);
 413
 414         if (!icap_enabled(fim))
 415                 frame_interval_monitor(fim, ts);
 416
 417         spin_unlock_irqrestore(&fim->lock, flags);
 418 }
 419 EXPORT_SYMBOL_GPL(imx_media_fim_eof_monitor);
 420
 421 /* Called by the subdev in its s_stream callback */
 422 int imx_media_fim_set_stream(struct imx_media_fim *fim,
 423                              const struct v4l2_fract *fi,
 424                              bool on)
 425 {
 426         unsigned long flags;
 427         int ret = 0;
 428
 429         v4l2_ctrl_lock(fim->ctrl[FIM_CL_ENABLE]);
 430
 431         if (fim->stream_on == on)
 432                 goto out;
 433
 434         if (on) {
 435                 spin_lock_irqsave(&fim->lock, flags);
 436                 reset_fim(fim, true);
 437                 update_fim_nominal(fim, fi);
 438                 spin_unlock_irqrestore(&fim->lock, flags);
 439
 440                 if (icap_enabled(fim)) {
 441                         ret = fim_request_input_capture(fim);
 442                         if (ret)
 443                                 goto out;
 444                         fim_acquire_first_ts(fim);
 445                 }
 446         } else {
 447                 if (icap_enabled(fim))
 448                         fim_free_input_capture(fim);
 449         }
 450
 451         fim->stream_on = on;
 452 out:
 453         v4l2_ctrl_unlock(fim->ctrl[FIM_CL_ENABLE]);
 454         return ret;
 455 }
 456 EXPORT_SYMBOL_GPL(imx_media_fim_set_stream);
 457
 458 int imx_media_fim_add_controls(struct imx_media_fim *fim)
 459 {
 460         /* add the FIM controls to the calling subdev ctrl handler */
 461         return v4l2_ctrl_add_handler(fim->sd->ctrl_handler,
 462                                      &fim->ctrl_handler, NULL);
 463 }
 464 EXPORT_SYMBOL_GPL(imx_media_fim_add_controls);
 465
 466 /* Called by the subdev in its subdev registered callback */
 467 struct imx_media_fim *imx_media_fim_init(struct v4l2_subdev *sd)
 468 {
 469         struct imx_media_fim *fim;
 470         int ret;
 471
 472         fim = devm_kzalloc(sd->dev, sizeof(*fim), GFP_KERNEL);
 473         if (!fim)
 474                 return ERR_PTR(-ENOMEM);
 475
 476         /* get media device */
 477         fim->md = dev_get_drvdata(sd->v4l2_dev->dev);
 478         fim->sd = sd;
 479
 480         spin_lock_init(&fim->lock);
 481
 482         ret = init_fim_controls(fim);
 483         if (ret)
 484                 return ERR_PTR(ret);
 485
 486         return fim;
 487 }
 488 EXPORT_SYMBOL_GPL(imx_media_fim_init);
 489
 490 void imx_media_fim_free(struct imx_media_fim *fim)
 491 {
 492         v4l2_ctrl_handler_free(&fim->ctrl_handler);
 493 }
 494 EXPORT_SYMBOL_GPL(imx_media_fim_free);