drivers/media/i2c/video-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * video-i2c.c - Support for I2C transport video devices
   4  *
   5  * Copyright (C) 2018 Matt Ranostay <matt.ranostay@konsulko.com>
   6  *
   7  * Supported:
   8  * - Panasonic AMG88xx Grid-Eye Sensors
   9  */
  10
  11 #include <linux/delay.h>
  12 #include <linux/freezer.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/kthread.h>
  15 #include <linux/i2c.h>
  16 #include <linux/list.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/of_device.h>
  20 #include <linux/sched.h>
  21 #include <linux/slab.h>
  22 #include <linux/videodev2.h>
  23 #include <media/v4l2-common.h>
  24 #include <media/v4l2-device.h>
  25 #include <media/v4l2-event.h>
  26 #include <media/v4l2-fh.h>
  27 #include <media/v4l2-ioctl.h>
  28 #include <media/videobuf2-v4l2.h>
  29 #include <media/videobuf2-vmalloc.h>
  30
  31 #define VIDEO_I2C_DRIVER        "video-i2c"
  32
  33 struct video_i2c_chip;
  34
  35 struct video_i2c_buffer {
  36         struct vb2_v4l2_buffer vb;
  37         struct list_head list;
  38 };
  39
  40 struct video_i2c_data {
  41         struct i2c_client *client;
  42         const struct video_i2c_chip *chip;
  43         struct mutex lock;
  44         spinlock_t slock;
  45         unsigned int sequence;
  46         struct mutex queue_lock;
  47
  48         struct v4l2_device v4l2_dev;
  49         struct video_device vdev;
  50         struct vb2_queue vb_vidq;
  51
  52         struct task_struct *kthread_vid_cap;
  53         struct list_head vid_cap_active;
  54 };
  55
  56 static const struct v4l2_fmtdesc amg88xx_format = {
  57         .pixelformat = V4L2_PIX_FMT_Y12,
  58 };
  59
  60 static const struct v4l2_frmsize_discrete amg88xx_size = {
  61         .width = 8,
  62         .height = 8,
  63 };
  64
  65 struct video_i2c_chip {
  66         /* video dimensions */
  67         const struct v4l2_fmtdesc *format;
  68         const struct v4l2_frmsize_discrete *size;
  69
  70         /* max frames per second */
  71         unsigned int max_fps;
  72
  73         /* pixel buffer size */
  74         unsigned int buffer_size;
  75
  76         /* pixel size in bits */
  77         unsigned int bpp;
  78
  79         /* xfer function */
  80         int (*xfer)(struct video_i2c_data *data, char *buf);
  81
  82         /* hwmon init function */
  83         int (*hwmon_init)(struct video_i2c_data *data);
  84 };
  85
  86 static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
  87 {
  88         struct i2c_client *client = data->client;
  89         struct i2c_msg msg[2];
  90         u8 reg = 0x80;
  91         int ret;
  92
  93         msg[0].addr = client->addr;
  94         msg[0].flags = 0;
  95         msg[0].len = 1;
  96         msg[0].buf  = (char *)&reg;
  97
  98         msg[1].addr = client->addr;
  99         msg[1].flags = I2C_M_RD;
 100         msg[1].len = data->chip->buffer_size;
 101         msg[1].buf = (char *)buf;
 102
 103         ret = i2c_transfer(client->adapter, msg, 2);
 104
 105         return (ret == 2) ? 0 : -EIO;
 106 }
 107
 108 #if IS_REACHABLE(CONFIG_HWMON)
 109
 110 static const u32 amg88xx_temp_config[] = {
 111         HWMON_T_INPUT,
 112         0
 113 };
 114
 115 static const struct hwmon_channel_info amg88xx_temp = {
 116         .type = hwmon_temp,
 117         .config = amg88xx_temp_config,
 118 };
 119
 120 static const struct hwmon_channel_info *amg88xx_info[] = {
 121         &amg88xx_temp,
 122         NULL
 123 };
 124
 125 static umode_t amg88xx_is_visible(const void *drvdata,
 126                                   enum hwmon_sensor_types type,
 127                                   u32 attr, int channel)
 128 {
 129         return 0444;
 130 }
 131
 132 static int amg88xx_read(struct device *dev, enum hwmon_sensor_types type,
 133                         u32 attr, int channel, long *val)
 134 {
 135         struct video_i2c_data *data = dev_get_drvdata(dev);
 136         struct i2c_client *client = data->client;
 137         int tmp = i2c_smbus_read_word_data(client, 0x0e);
 138
 139         if (tmp < 0)
 140                 return tmp;
 141
 142         /*
 143          * Check for sign bit, this isn't a two's complement value but an
 144          * absolute temperature that needs to be inverted in the case of being
 145          * negative.
 146          */
 147         if (tmp & BIT(11))
 148                 tmp = -(tmp & 0x7ff);
 149
 150         *val = (tmp * 625) / 10;
 151
 152         return 0;
 153 }
 154
 155 static const struct hwmon_ops amg88xx_hwmon_ops = {
 156         .is_visible = amg88xx_is_visible,
 157         .read = amg88xx_read,
 158 };
 159
 160 static const struct hwmon_chip_info amg88xx_chip_info = {
 161         .ops = &amg88xx_hwmon_ops,
 162         .info = amg88xx_info,
 163 };
 164
 165 static int amg88xx_hwmon_init(struct video_i2c_data *data)
 166 {
 167         void *hwmon = devm_hwmon_device_register_with_info(&data->client->dev,
 168                                 "amg88xx", data, &amg88xx_chip_info, NULL);
 169
 170         return PTR_ERR_OR_ZERO(hwmon);
 171 }
 172 #else
 173 #define amg88xx_hwmon_init      NULL
 174 #endif
 175
 176 #define AMG88XX         0
 177
 178 static const struct video_i2c_chip video_i2c_chip[] = {
 179         [AMG88XX] = {
 180                 .size           = &amg88xx_size,
 181                 .format         = &amg88xx_format,
 182                 .max_fps        = 10,
 183                 .buffer_size    = 128,
 184                 .bpp            = 16,
 185                 .xfer           = &amg88xx_xfer,
 186                 .hwmon_init     = amg88xx_hwmon_init,
 187         },
 188 };
 189
 190 static const struct v4l2_file_operations video_i2c_fops = {
 191         .owner          = THIS_MODULE,
 192         .open           = v4l2_fh_open,
 193         .release        = vb2_fop_release,
 194         .poll           = vb2_fop_poll,
 195         .read           = vb2_fop_read,
 196         .mmap           = vb2_fop_mmap,
 197         .unlocked_ioctl = video_ioctl2,
 198 };
 199
 200 static int queue_setup(struct vb2_queue *vq,
 201                        unsigned int *nbuffers, unsigned int *nplanes,
 202                        unsigned int sizes[], struct device *alloc_devs[])
 203 {
 204         struct video_i2c_data *data = vb2_get_drv_priv(vq);
 205         unsigned int size = data->chip->buffer_size;
 206
 207         if (vq->num_buffers + *nbuffers < 2)
 208                 *nbuffers = 2;
 209
 210         if (*nplanes)
 211                 return sizes[0] < size ? -EINVAL : 0;
 212
 213         *nplanes = 1;
 214         sizes[0] = size;
 215
 216         return 0;
 217 }
 218
 219 static int buffer_prepare(struct vb2_buffer *vb)
 220 {
 221         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 222         struct video_i2c_data *data = vb2_get_drv_priv(vb->vb2_queue);
 223         unsigned int size = data->chip->buffer_size;
 224
 225         if (vb2_plane_size(vb, 0) < size)
 226                 return -EINVAL;
 227
 228         vbuf->field = V4L2_FIELD_NONE;
 229         vb2_set_plane_payload(vb, 0, size);
 230
 231         return 0;
 232 }
 233
 234 static void buffer_queue(struct vb2_buffer *vb)
 235 {
 236         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 237         struct video_i2c_data *data = vb2_get_drv_priv(vb->vb2_queue);
 238         struct video_i2c_buffer *buf =
 239                         container_of(vbuf, struct video_i2c_buffer, vb);
 240
 241         spin_lock(&data->slock);
 242         list_add_tail(&buf->list, &data->vid_cap_active);
 243         spin_unlock(&data->slock);
 244 }
 245
 246 static int video_i2c_thread_vid_cap(void *priv)
 247 {
 248         struct video_i2c_data *data = priv;
 249         unsigned int delay = msecs_to_jiffies(1000 / data->chip->max_fps);
 250
 251         set_freezable();
 252
 253         do {
 254                 unsigned long start_jiffies = jiffies;
 255                 struct video_i2c_buffer *vid_cap_buf = NULL;
 256                 int schedule_delay;
 257
 258                 try_to_freeze();
 259
 260                 spin_lock(&data->slock);
 261
 262                 if (!list_empty(&data->vid_cap_active)) {
 263                         vid_cap_buf = list_last_entry(&data->vid_cap_active,
 264                                                  struct video_i2c_buffer, list);
 265                         list_del(&vid_cap_buf->list);
 266                 }
 267
 268                 spin_unlock(&data->slock);
 269
 270                 if (vid_cap_buf) {
 271                         struct vb2_buffer *vb2_buf = &vid_cap_buf->vb.vb2_buf;
 272                         void *vbuf = vb2_plane_vaddr(vb2_buf, 0);
 273                         int ret;
 274
 275                         ret = data->chip->xfer(data, vbuf);
 276                         vb2_buf->timestamp = ktime_get_ns();
 277                         vid_cap_buf->vb.sequence = data->sequence++;
 278                         vb2_buffer_done(vb2_buf, ret ?
 279                                 VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
 280                 }
 281
 282                 schedule_delay = delay - (jiffies - start_jiffies);
 283
 284                 if (time_after(jiffies, start_jiffies + delay))
 285                         schedule_delay = delay;
 286
 287                 schedule_timeout_interruptible(schedule_delay);
 288         } while (!kthread_should_stop());
 289
 290         return 0;
 291 }
 292
 293 static void video_i2c_del_list(struct vb2_queue *vq, enum vb2_buffer_state state)
 294 {
 295         struct video_i2c_data *data = vb2_get_drv_priv(vq);
 296         struct video_i2c_buffer *buf, *tmp;
 297
 298         spin_lock(&data->slock);
 299
 300         list_for_each_entry_safe(buf, tmp, &data->vid_cap_active, list) {
 301                 list_del(&buf->list);
 302                 vb2_buffer_done(&buf->vb.vb2_buf, state);
 303         }
 304
 305         spin_unlock(&data->slock);
 306 }
 307
 308 static int start_streaming(struct vb2_queue *vq, unsigned int count)
 309 {
 310         struct video_i2c_data *data = vb2_get_drv_priv(vq);
 311
 312         if (data->kthread_vid_cap)
 313                 return 0;
 314
 315         data->sequence = 0;
 316         data->kthread_vid_cap = kthread_run(video_i2c_thread_vid_cap, data,
 317                                             "%s-vid-cap", data->v4l2_dev.name);
 318         if (!IS_ERR(data->kthread_vid_cap))
 319                 return 0;
 320
 321         video_i2c_del_list(vq, VB2_BUF_STATE_QUEUED);
 322
 323         return PTR_ERR(data->kthread_vid_cap);
 324 }
 325
 326 static void stop_streaming(struct vb2_queue *vq)
 327 {
 328         struct video_i2c_data *data = vb2_get_drv_priv(vq);
 329
 330         if (data->kthread_vid_cap == NULL)
 331                 return;
 332
 333         kthread_stop(data->kthread_vid_cap);
 334         data->kthread_vid_cap = NULL;
 335
 336         video_i2c_del_list(vq, VB2_BUF_STATE_ERROR);
 337 }
 338
 339 static struct vb2_ops video_i2c_video_qops = {
 340         .queue_setup            = queue_setup,
 341         .buf_prepare            = buffer_prepare,
 342         .buf_queue              = buffer_queue,
 343         .start_streaming        = start_streaming,
 344         .stop_streaming         = stop_streaming,
 345         .wait_prepare           = vb2_ops_wait_prepare,
 346         .wait_finish            = vb2_ops_wait_finish,
 347 };
 348
 349 static int video_i2c_querycap(struct file *file, void  *priv,
 350                                 struct v4l2_capability *vcap)
 351 {
 352         struct video_i2c_data *data = video_drvdata(file);
 353         struct i2c_client *client = data->client;
 354
 355         strlcpy(vcap->driver, data->v4l2_dev.name, sizeof(vcap->driver));
 356         strlcpy(vcap->card, data->vdev.name, sizeof(vcap->card));
 357
 358         sprintf(vcap->bus_info, "I2C:%d-%d", client->adapter->nr, client->addr);
 359
 360         return 0;
 361 }
 362
 363 static int video_i2c_g_input(struct file *file, void *fh, unsigned int *inp)
 364 {
 365         *inp = 0;
 366
 367         return 0;
 368 }
 369
 370 static int video_i2c_s_input(struct file *file, void *fh, unsigned int inp)
 371 {
 372         return (inp > 0) ? -EINVAL : 0;
 373 }
 374
 375 static int video_i2c_enum_input(struct file *file, void *fh,
 376                                   struct v4l2_input *vin)
 377 {
 378         if (vin->index > 0)
 379                 return -EINVAL;
 380
 381         strlcpy(vin->name, "Camera", sizeof(vin->name));
 382
 383         vin->type = V4L2_INPUT_TYPE_CAMERA;
 384
 385         return 0;
 386 }
 387
 388 static int video_i2c_enum_fmt_vid_cap(struct file *file, void *fh,
 389                                         struct v4l2_fmtdesc *fmt)
 390 {
 391         struct video_i2c_data *data = video_drvdata(file);
 392         enum v4l2_buf_type type = fmt->type;
 393
 394         if (fmt->index > 0)
 395                 return -EINVAL;
 396
 397         *fmt = *data->chip->format;
 398         fmt->type = type;
 399
 400         return 0;
 401 }
 402
 403 static int video_i2c_enum_framesizes(struct file *file, void *fh,
 404                                        struct v4l2_frmsizeenum *fsize)
 405 {
 406         const struct video_i2c_data *data = video_drvdata(file);
 407         const struct v4l2_frmsize_discrete *size = data->chip->size;
 408
 409         /* currently only one frame size is allowed */
 410         if (fsize->index > 0)
 411                 return -EINVAL;
 412
 413         if (fsize->pixel_format != data->chip->format->pixelformat)
 414                 return -EINVAL;
 415
 416         fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 417         fsize->discrete.width = size->width;
 418         fsize->discrete.height = size->height;
 419
 420         return 0;
 421 }
 422
 423 static int video_i2c_enum_frameintervals(struct file *file, void *priv,
 424                                            struct v4l2_frmivalenum *fe)
 425 {
 426         const struct video_i2c_data *data = video_drvdata(file);
 427         const struct v4l2_frmsize_discrete *size = data->chip->size;
 428
 429         if (fe->index > 0)
 430                 return -EINVAL;
 431
 432         if (fe->width != size->width || fe->height != size->height)
 433                 return -EINVAL;
 434
 435         fe->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 436         fe->discrete.numerator = 1;
 437         fe->discrete.denominator = data->chip->max_fps;
 438
 439         return 0;
 440 }
 441
 442 static int video_i2c_try_fmt_vid_cap(struct file *file, void *fh,
 443                                        struct v4l2_format *fmt)
 444 {
 445         const struct video_i2c_data *data = video_drvdata(file);
 446         const struct v4l2_frmsize_discrete *size = data->chip->size;
 447         struct v4l2_pix_format *pix = &fmt->fmt.pix;
 448         unsigned int bpp = data->chip->bpp / 8;
 449
 450         pix->width = size->width;
 451         pix->height = size->height;
 452         pix->pixelformat = data->chip->format->pixelformat;
 453         pix->field = V4L2_FIELD_NONE;
 454         pix->bytesperline = pix->width * bpp;
 455         pix->sizeimage = pix->bytesperline * pix->height;
 456         pix->colorspace = V4L2_COLORSPACE_RAW;
 457
 458         return 0;
 459 }
 460
 461 static int video_i2c_s_fmt_vid_cap(struct file *file, void *fh,
 462                                      struct v4l2_format *fmt)
 463 {
 464         struct video_i2c_data *data = video_drvdata(file);
 465
 466         if (vb2_is_busy(&data->vb_vidq))
 467                 return -EBUSY;
 468
 469         return video_i2c_try_fmt_vid_cap(file, fh, fmt);
 470 }
 471
 472 static int video_i2c_g_parm(struct file *filp, void *priv,
 473                               struct v4l2_streamparm *parm)
 474 {
 475         struct video_i2c_data *data = video_drvdata(filp);
 476
 477         if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 478                 return -EINVAL;
 479
 480         parm->parm.capture.readbuffers = 1;
 481         parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
 482         parm->parm.capture.timeperframe.numerator = 1;
 483         parm->parm.capture.timeperframe.denominator = data->chip->max_fps;
 484
 485         return 0;
 486 }
 487
 488 static const struct v4l2_ioctl_ops video_i2c_ioctl_ops = {
 489         .vidioc_querycap                = video_i2c_querycap,
 490         .vidioc_g_input                 = video_i2c_g_input,
 491         .vidioc_s_input                 = video_i2c_s_input,
 492         .vidioc_enum_input              = video_i2c_enum_input,
 493         .vidioc_enum_fmt_vid_cap        = video_i2c_enum_fmt_vid_cap,
 494         .vidioc_enum_framesizes         = video_i2c_enum_framesizes,
 495         .vidioc_enum_frameintervals     = video_i2c_enum_frameintervals,
 496         .vidioc_g_fmt_vid_cap           = video_i2c_try_fmt_vid_cap,
 497         .vidioc_s_fmt_vid_cap           = video_i2c_s_fmt_vid_cap,
 498         .vidioc_g_parm                  = video_i2c_g_parm,
 499         .vidioc_s_parm                  = video_i2c_g_parm,
 500         .vidioc_try_fmt_vid_cap         = video_i2c_try_fmt_vid_cap,
 501         .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
 502         .vidioc_create_bufs             = vb2_ioctl_create_bufs,
 503         .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
 504         .vidioc_querybuf                = vb2_ioctl_querybuf,
 505         .vidioc_qbuf                    = vb2_ioctl_qbuf,
 506         .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
 507         .vidioc_streamon                = vb2_ioctl_streamon,
 508         .vidioc_streamoff               = vb2_ioctl_streamoff,
 509 };
 510
 511 static void video_i2c_release(struct video_device *vdev)
 512 {
 513         struct video_i2c_data *data = video_get_drvdata(vdev);
 514
 515         v4l2_device_unregister(&data->v4l2_dev);
 516         mutex_destroy(&data->lock);
 517         mutex_destroy(&data->queue_lock);
 518         kfree(data);
 519 }
 520
 521 static int video_i2c_probe(struct i2c_client *client,
 522                              const struct i2c_device_id *id)
 523 {
 524         struct video_i2c_data *data;
 525         struct v4l2_device *v4l2_dev;
 526         struct vb2_queue *queue;
 527         int ret = -ENODEV;
 528
 529         data = kzalloc(sizeof(*data), GFP_KERNEL);
 530         if (!data)
 531                 return -ENOMEM;
 532
 533         if (dev_fwnode(&client->dev))
 534                 data->chip = device_get_match_data(&client->dev);
 535         else if (id)
 536                 data->chip = &video_i2c_chip[id->driver_data];
 537         else
 538                 goto error_free_device;
 539
 540         data->client = client;
 541         v4l2_dev = &data->v4l2_dev;
 542         strlcpy(v4l2_dev->name, VIDEO_I2C_DRIVER, sizeof(v4l2_dev->name));
 543
 544         ret = v4l2_device_register(&client->dev, v4l2_dev);
 545         if (ret < 0)
 546                 goto error_free_device;
 547
 548         mutex_init(&data->lock);
 549         mutex_init(&data->queue_lock);
 550
 551         queue = &data->vb_vidq;
 552         queue->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 553         queue->io_modes = VB2_DMABUF | VB2_MMAP | VB2_USERPTR | VB2_READ;
 554         queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
 555         queue->drv_priv = data;
 556         queue->buf_struct_size = sizeof(struct video_i2c_buffer);
 557         queue->min_buffers_needed = 1;
 558         queue->ops = &video_i2c_video_qops;
 559         queue->mem_ops = &vb2_vmalloc_memops;
 560
 561         ret = vb2_queue_init(queue);
 562         if (ret < 0)
 563                 goto error_unregister_device;
 564
 565         data->vdev.queue = queue;
 566         data->vdev.queue->lock = &data->queue_lock;
 567
 568         snprintf(data->vdev.name, sizeof(data->vdev.name),
 569                                  "I2C %d-%d Transport Video",
 570                                  client->adapter->nr, client->addr);
 571
 572         data->vdev.v4l2_dev = v4l2_dev;
 573         data->vdev.fops = &video_i2c_fops;
 574         data->vdev.lock = &data->lock;
 575         data->vdev.ioctl_ops = &video_i2c_ioctl_ops;
 576         data->vdev.release = video_i2c_release;
 577         data->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE |
 578                                  V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
 579
 580         spin_lock_init(&data->slock);
 581         INIT_LIST_HEAD(&data->vid_cap_active);
 582
 583         video_set_drvdata(&data->vdev, data);
 584         i2c_set_clientdata(client, data);
 585
 586         if (data->chip->hwmon_init) {
 587                 ret = data->chip->hwmon_init(data);
 588                 if (ret < 0) {
 589                         dev_warn(&client->dev,
 590                                  "failed to register hwmon device\n");
 591                 }
 592         }
 593
 594         ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
 595         if (ret < 0)
 596                 goto error_unregister_device;
 597
 598         return 0;
 599
 600 error_unregister_device:
 601         v4l2_device_unregister(v4l2_dev);
 602         mutex_destroy(&data->lock);
 603         mutex_destroy(&data->queue_lock);
 604
 605 error_free_device:
 606         kfree(data);
 607
 608         return ret;
 609 }
 610
 611 static int video_i2c_remove(struct i2c_client *client)
 612 {
 613         struct video_i2c_data *data = i2c_get_clientdata(client);
 614
 615         video_unregister_device(&data->vdev);
 616
 617         return 0;
 618 }
 619
 620 static const struct i2c_device_id video_i2c_id_table[] = {
 621         { "amg88xx", AMG88XX },
 622         {}
 623 };
 624 MODULE_DEVICE_TABLE(i2c, video_i2c_id_table);
 625
 626 static const struct of_device_id video_i2c_of_match[] = {
 627         { .compatible = "panasonic,amg88xx", .data = &video_i2c_chip[AMG88XX] },
 628         {}
 629 };
 630 MODULE_DEVICE_TABLE(of, video_i2c_of_match);
 631
 632 static struct i2c_driver video_i2c_driver = {
 633         .driver = {
 634                 .name   = VIDEO_I2C_DRIVER,
 635                 .of_match_table = video_i2c_of_match,
 636         },
 637         .probe          = video_i2c_probe,
 638         .remove         = video_i2c_remove,
 639         .id_table       = video_i2c_id_table,
 640 };
 641
 642 module_i2c_driver(video_i2c_driver);
 643
 644 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
 645 MODULE_DESCRIPTION("I2C transport video support");
 646 MODULE_LICENSE("GPL v2");