target/linux/brcm2708/patches-4.19/950-0282-media-bcm2835-unicam-Power-on-subdev-on-open-release.patch

   1 From bf1805e0c8c4fc05e2a13b0a03b510ff4e523418 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.org>
   3 Date: Tue, 29 Jan 2019 15:56:10 +0000
   4 Subject: [PATCH] media:bcm2835-unicam: Power on subdev on
   5  open/release, not streaming
   6
   7 The driver was powering on the source subdevice as part of STREAMON,
   8 and powering it off in STREAMOFF. This isn't so great if there is a
   9 significant amount of setup required for your device.
  10
  11 Copy the approach taken in the Atmel ISC driver where s_power(1) is called
  12 on first file handle open, and s_power(0) is called on the last release.
  13
  14 See https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=232437
  15
  16 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
  17 ---
  18  .../media/platform/bcm2835/bcm2835-unicam.c   | 68 +++++++++++++++----
  19  1 file changed, 54 insertions(+), 14 deletions(-)
  20
  21 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  22 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  23 @@ -1237,11 +1237,6 @@ static int unicam_start_streaming(struct
  24                 unicam_err(dev, "Failed to enable CSI clock: %d\n", ret);
  25                 goto err_pm_put;
  26         }
  27 -       ret = v4l2_subdev_call(dev->sensor, core, s_power, 1);
  28 -       if (ret < 0 && ret != -ENOIOCTLCMD) {
  29 -               unicam_err(dev, "power on failed in subdev\n");
  30 -               goto err_clock_unprepare;
  31 -       }
  32         dev->streaming = 1;
  33
  34         unicam_start_rx(dev, addr);
  35 @@ -1256,8 +1251,6 @@ static int unicam_start_streaming(struct
  36
  37  err_disable_unicam:
  38         unicam_disable(dev);
  39 -       v4l2_subdev_call(dev->sensor, core, s_power, 0);
  40 -err_clock_unprepare:
  41         clk_disable_unprepare(dev->clock);
  42  err_pm_put:
  43         unicam_runtime_put(dev);
  44 @@ -1306,11 +1299,6 @@ static void unicam_stop_streaming(struct
  45         dev->next_frm = NULL;
  46         spin_unlock_irqrestore(&dev->dma_queue_lock, flags);
  47
  48 -       if (v4l2_subdev_has_op(dev->sensor, core, s_power)) {
  49 -               if (v4l2_subdev_call(dev->sensor, core, s_power, 0) < 0)
  50 -                       unicam_err(dev, "power off failed in subdev\n");
  51 -       }
  52 -
  53         clk_disable_unprepare(dev->clock);
  54         unicam_runtime_put(dev);
  55  }
  56 @@ -1543,11 +1531,63 @@ static const struct vb2_ops unicam_video
  57         .stop_streaming         = unicam_stop_streaming,
  58  };
  59
  60 +/*
  61 + * unicam_open : This function is based on the v4l2_fh_open helper function.
  62 + * It has been augmented to handle sensor subdevice power management,
  63 + */
  64 +static int unicam_open(struct file *file)
  65 +{
  66 +       struct unicam_device *dev = video_drvdata(file);
  67 +       int ret;
  68 +
  69 +       mutex_lock(&dev->lock);
  70 +
  71 +       ret = v4l2_fh_open(file);
  72 +       if (ret) {
  73 +               unicam_err(dev, "v4l2_fh_open failed\n");
  74 +               goto unlock;
  75 +       }
  76 +
  77 +       if (!v4l2_fh_is_singular_file(file))
  78 +               goto unlock;
  79 +
  80 +       ret = v4l2_subdev_call(dev->sensor, core, s_power, 1);
  81 +       if (ret < 0 && ret != -ENOIOCTLCMD) {
  82 +               v4l2_fh_release(file);
  83 +               goto unlock;
  84 +       }
  85 +
  86 +unlock:
  87 +       mutex_unlock(&dev->lock);
  88 +       return ret;
  89 +}
  90 +
  91 +static int unicam_release(struct file *file)
  92 +{
  93 +       struct unicam_device *dev = video_drvdata(file);
  94 +       struct v4l2_subdev *sd = dev->sensor;
  95 +       bool fh_singular;
  96 +       int ret;
  97 +
  98 +       mutex_lock(&dev->lock);
  99 +
 100 +       fh_singular = v4l2_fh_is_singular_file(file);
 101 +
 102 +       ret = _vb2_fop_release(file, NULL);
 103 +
 104 +       if (fh_singular)
 105 +               v4l2_subdev_call(sd, core, s_power, 0);
 106 +
 107 +       mutex_unlock(&dev->lock);
 108 +
 109 +       return ret;
 110 +}
 111 +
 112  /* unicam capture driver file operations */
 113  static const struct v4l2_file_operations unicam_fops = {
 114         .owner          = THIS_MODULE,
 115 -       .open           = v4l2_fh_open,
 116 -       .release        = vb2_fop_release,
 117 +       .open           = unicam_open,
 118 +       .release        = unicam_release,
 119         .read           = vb2_fop_read,
 120         .poll           = vb2_fop_poll,
 121         .unlocked_ioctl = video_ioctl2,