target/linux/bcm27xx/patches-5.4/950-0899-media-bcm2835-unicam-Set-VPU-min-clock-freq-to-250Mh.patch

   1 From 09c1533f7f5dabd79aa2018083d1b71d26cd7eda 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  arch/arm/boot/dts/bcm270x.dtsi                | 10 ++--
  14  .../media/platform/bcm2835/bcm2835-unicam.c   | 49 +++++++++++++++++--
  15  2 files changed, 50 insertions(+), 9 deletions(-)
  16
  17 --- a/arch/arm/boot/dts/bcm270x.dtsi
  18 +++ b/arch/arm/boot/dts/bcm270x.dtsi
  19 @@ -88,8 +88,9 @@
  20                         reg = <0x7e800000 0x800>,
  21                               <0x7e802000 0x4>;
  22                         interrupts = <2 6>;
  23 -                       clocks = <&clocks BCM2835_CLOCK_CAM0>;
  24 -                       clock-names = "lp";
  25 +                       clocks = <&clocks BCM2835_CLOCK_CAM0>,
  26 +                                <&firmware_clocks 4>;
  27 +                       clock-names = "lp", "vpu";
  28                         power-domains = <&power RPI_POWER_DOMAIN_UNICAM0>;
  29                         #address-cells = <1>;
  30                         #size-cells = <0>;
  31 @@ -102,8 +103,9 @@
  32                         reg = <0x7e801000 0x800>,
  33                               <0x7e802004 0x4>;
  34                         interrupts = <2 7>;
  35 -                       clocks = <&clocks BCM2835_CLOCK_CAM1>;
  36 -                       clock-names = "lp";
  37 +                       clocks = <&clocks BCM2835_CLOCK_CAM1>,
  38 +                                <&firmware_clocks 4>;
  39 +                       clock-names = "lp", "vpu";
  40                         power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>;
  41                         #address-cells = <1>;
  42                         #size-cells = <0>;
  43 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  44 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  45 @@ -89,6 +89,11 @@ MODULE_PARM_DESC(debug, "Debug level 0-3
  46                 v4l2_err(&(dev)->v4l2_dev, fmt, ##arg)
  47
  48  /*
  49 + * Unicam must request a minimum of 250Mhz from the VPU clock.
  50 + * Otherwise the input FIFOs overrun and cause image corruption.
  51 + */
  52 +#define MIN_VPU_CLOCK_RATE (250 * 1000 * 1000)
  53 +/*
  54   * To protect against a dodgy sensor driver never returning an error from
  55   * enum_mbus_code, set a maximum index value to be used.
  56   */
  57 @@ -417,8 +422,10 @@ struct unicam_device {
  58         void __iomem *base;
  59         /* clock gating base address */
  60         void __iomem *clk_gate_base;
  61 -       /* clock handle */
  62 +       /* lp clock handle */
  63         struct clk *clock;
  64 +       /* vpu clock handle */
  65 +       struct clk *vpu_clock;
  66         /* V4l2 device */
  67         struct v4l2_device v4l2_dev;
  68         struct media_device mdev;
  69 @@ -1674,16 +1681,28 @@ static int unicam_start_streaming(struct
  70         unicam_dbg(1, dev, "Running with %u data lanes\n",
  71                    dev->active_data_lanes);
  72
  73 -       ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
  74 +       ret = clk_set_min_rate(dev->vpu_clock, MIN_VPU_CLOCK_RATE);
  75 +       if (ret) {
  76 +               unicam_err(dev, "failed to set up VPU clock\n");
  77 +               goto err_pm_put;
  78 +       }
  79 +
  80 +       ret = clk_prepare_enable(dev->vpu_clock);
  81         if (ret) {
  82 -               unicam_err(dev, "failed to set up clock\n");
  83 +               unicam_err(dev, "Failed to enable VPU clock: %d\n", ret);
  84                 goto err_pm_put;
  85         }
  86
  87 +       ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
  88 +       if (ret) {
  89 +               unicam_err(dev, "failed to set up CSI clock\n");
  90 +               goto err_vpu_clock;
  91 +       }
  92 +
  93         ret = clk_prepare_enable(dev->clock);
  94         if (ret) {
  95                 unicam_err(dev, "Failed to enable CSI clock: %d\n", ret);
  96 -               goto err_pm_put;
  97 +               goto err_vpu_clock;
  98         }
  99
 100         for (i = 0; i < ARRAY_SIZE(dev->node); i++) {
 101 @@ -1717,6 +1736,11 @@ static int unicam_start_streaming(struct
 102  err_disable_unicam:
 103         unicam_disable(dev);
 104         clk_disable_unprepare(dev->clock);
 105 +err_vpu_clock:
 106 +       ret = clk_set_min_rate(dev->vpu_clock, 0);
 107 +       if (ret)
 108 +               unicam_err(dev, "failed to reset the VPU clock\n");
 109 +       clk_disable_unprepare(dev->vpu_clock);
 110  err_pm_put:
 111         unicam_runtime_put(dev);
 112  err_streaming:
 113 @@ -1734,6 +1758,8 @@ static void unicam_stop_streaming(struct
 114         node->streaming = false;
 115
 116         if (node->pad_id == IMAGE_PAD) {
 117 +               int ret;
 118 +
 119                 /*
 120                  * Stop streaming the sensor and disable the peripheral.
 121                  * We cannot continue streaming embedded data with the
 122 @@ -1743,6 +1769,12 @@ static void unicam_stop_streaming(struct
 123                         unicam_err(dev, "stream off failed in subdev\n");
 124
 125                 unicam_disable(dev);
 126 +
 127 +               ret = clk_set_min_rate(dev->vpu_clock, 0);
 128 +               if (ret)
 129 +                       unicam_err(dev, "failed to reset the min VPU clock\n");
 130 +
 131 +               clk_disable_unprepare(dev->vpu_clock);
 132                 clk_disable_unprepare(dev->clock);
 133                 unicam_runtime_put(dev);
 134
 135 @@ -2742,11 +2774,18 @@ static int unicam_probe(struct platform_
 136
 137         unicam->clock = devm_clk_get(&pdev->dev, "lp");
 138         if (IS_ERR(unicam->clock)) {
 139 -               unicam_err(unicam, "Failed to get clock\n");
 140 +               unicam_err(unicam, "Failed to get lp clock\n");
 141                 ret = PTR_ERR(unicam->clock);
 142                 goto err_unicam_put;
 143         }
 144
 145 +       unicam->vpu_clock = devm_clk_get(&pdev->dev, "vpu");
 146 +       if (IS_ERR(unicam->vpu_clock)) {
 147 +               unicam_err(unicam, "Failed to get vpu clock\n");
 148 +               ret = PTR_ERR(unicam->vpu_clock);
 149 +               goto err_unicam_put;
 150 +       }
 151 +
 152         ret = platform_get_irq(pdev, 0);
 153         if (ret <= 0) {
 154                 dev_err(&pdev->dev, "No IRQ resource\n");