git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From a0dc48f88e494f662af2378aa9f1c6191e556487 Mon Sep 17 00:00:00 2001
   2 From: Naushir Patuck <naush@raspberrypi.com>
   3 Date: Mon, 11 May 2020 13:02:22 +0100
   4 Subject: [PATCH] media: bcm2835: unicam: Set VPU min clock freq to
   5  250Mhz.
   6
   7 When streaming with Unicam, the VPU must have a clock frequency of at
   8 least 250Mhz.  Otherwise, the input fifos could overrun, causing
   9 image corruption.
  10
  11 Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
  12 ---
  13  .../media/platform/bcm2835/bcm2835-unicam.c   | 49 +++++++++++++++++--
  14  1 file changed, 44 insertions(+), 5 deletions(-)
  15
  16 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  17 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  18 @@ -91,6 +91,11 @@ MODULE_PARM_DESC(debug, "Debug level 0-3
  19                 v4l2_err(&(dev)->v4l2_dev, fmt, ##arg)
  20
  21  /*
  22 + * Unicam must request a minimum of 250Mhz from the VPU clock.
  23 + * Otherwise the input FIFOs overrun and cause image corruption.
  24 + */
  25 +#define MIN_VPU_CLOCK_RATE (250 * 1000 * 1000)
  26 +/*
  27   * To protect against a dodgy sensor driver never returning an error from
  28   * enum_mbus_code, set a maximum index value to be used.
  29   */
  30 @@ -419,8 +424,10 @@ struct unicam_device {
  31         void __iomem *base;
  32         /* clock gating base address */
  33         void __iomem *clk_gate_base;
  34 -       /* clock handle */
  35 +       /* lp clock handle */
  36         struct clk *clock;
  37 +       /* vpu clock handle */
  38 +       struct clk *vpu_clock;
  39         /* V4l2 device */
  40         struct v4l2_device v4l2_dev;
  41         struct media_device mdev;
  42 @@ -1680,16 +1687,28 @@ static int unicam_start_streaming(struct
  43         unicam_dbg(1, dev, "Running with %u data lanes\n",
  44                    dev->active_data_lanes);
  45
  46 -       ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
  47 +       ret = clk_set_min_rate(dev->vpu_clock, MIN_VPU_CLOCK_RATE);
  48 +       if (ret) {
  49 +               unicam_err(dev, "failed to set up VPU clock\n");
  50 +               goto err_pm_put;
  51 +       }
  52 +
  53 +       ret = clk_prepare_enable(dev->vpu_clock);
  54         if (ret) {
  55 -               unicam_err(dev, "failed to set up clock\n");
  56 +               unicam_err(dev, "Failed to enable VPU clock: %d\n", ret);
  57                 goto err_pm_put;
  58         }
  59
  60 +       ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
  61 +       if (ret) {
  62 +               unicam_err(dev, "failed to set up CSI clock\n");
  63 +               goto err_vpu_clock;
  64 +       }
  65 +
  66         ret = clk_prepare_enable(dev->clock);
  67         if (ret) {
  68                 unicam_err(dev, "Failed to enable CSI clock: %d\n", ret);
  69 -               goto err_pm_put;
  70 +               goto err_vpu_clock;
  71         }
  72
  73         for (i = 0; i < ARRAY_SIZE(dev->node); i++) {
  74 @@ -1723,6 +1742,11 @@ static int unicam_start_streaming(struct
  75  err_disable_unicam:
  76         unicam_disable(dev);
  77         clk_disable_unprepare(dev->clock);
  78 +err_vpu_clock:
  79 +       ret = clk_set_min_rate(dev->vpu_clock, 0);
  80 +       if (ret)
  81 +               unicam_err(dev, "failed to reset the VPU clock\n");
  82 +       clk_disable_unprepare(dev->vpu_clock);
  83  err_pm_put:
  84         unicam_runtime_put(dev);
  85  err_streaming:
  86 @@ -1740,6 +1764,8 @@ static void unicam_stop_streaming(struct
  87         node->streaming = false;
  88
  89         if (node->pad_id == IMAGE_PAD) {
  90 +               int ret;
  91 +
  92                 /*
  93                  * Stop streaming the sensor and disable the peripheral.
  94                  * We cannot continue streaming embedded data with the
  95 @@ -1749,6 +1775,12 @@ static void unicam_stop_streaming(struct
  96                         unicam_err(dev, "stream off failed in subdev\n");
  97
  98                 unicam_disable(dev);
  99 +
 100 +               ret = clk_set_min_rate(dev->vpu_clock, 0);
 101 +               if (ret)
 102 +                       unicam_err(dev, "failed to reset the min VPU clock\n");
 103 +
 104 +               clk_disable_unprepare(dev->vpu_clock);
 105                 clk_disable_unprepare(dev->clock);
 106                 unicam_runtime_put(dev);
 107
 108 @@ -2752,11 +2784,18 @@ static int unicam_probe(struct platform_
 109
 110         unicam->clock = devm_clk_get(&pdev->dev, "lp");
 111         if (IS_ERR(unicam->clock)) {
 112 -               unicam_err(unicam, "Failed to get clock\n");
 113 +               unicam_err(unicam, "Failed to get lp clock\n");
 114                 ret = PTR_ERR(unicam->clock);
 115                 goto err_unicam_put;
 116         }
 117
 118 +       unicam->vpu_clock = devm_clk_get(&pdev->dev, "vpu");
 119 +       if (IS_ERR(unicam->vpu_clock)) {
 120 +               unicam_err(unicam, "Failed to get vpu clock\n");
 121 +               ret = PTR_ERR(unicam->vpu_clock);
 122 +               goto err_unicam_put;
 123 +       }
 124 +
 125         ret = platform_get_irq(pdev, 0);
 126         if (ret <= 0) {
 127                 dev_err(&pdev->dev, "No IRQ resource\n");