target/linux/bcm27xx/patches-5.4/950-0616-drm-vc4-Kick-the-core-clock-up-during-a-mode-change.patch

   1 From 289c29b96fcc6cbe5c966fb0cc9e1bb8efbdd9dc Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 26 Mar 2020 15:32:19 +0000
   4 Subject: [PATCH] drm/vc4: Kick the core clock up during a mode change
   5
   6 Experimental commit to kick the core clock up during mode
   7 switching. This makes mode switching far more reliable, and
   8 mimics what the firmware does.
   9
  10 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  11 ---
  12  arch/arm/boot/dts/bcm2711.dtsi | 1 +
  13  drivers/gpu/drm/vc4/vc4_drv.h  | 2 ++
  14  drivers/gpu/drm/vc4/vc4_hvs.c  | 7 +++++++
  15  drivers/gpu/drm/vc4/vc4_kms.c  | 6 ++++++
  16  4 files changed, 16 insertions(+)
  17
  18 --- a/arch/arm/boot/dts/bcm2711.dtsi
  19 +++ b/arch/arm/boot/dts/bcm2711.dtsi
  20 @@ -306,6 +306,7 @@
  21                 };
  22
  23                 hvs@7e400000 {
  24 +                       clocks = <&firmware_clocks 4>;
  25                         interrupts = <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>;
  26                 };
  27
  28 --- a/drivers/gpu/drm/vc4/vc4_drv.h
  29 +++ b/drivers/gpu/drm/vc4/vc4_drv.h
  30 @@ -326,6 +326,8 @@ struct vc4_hvs {
  31         void __iomem *regs;
  32         u32 __iomem *dlist;
  33
  34 +       struct clk *core_clk;
  35 +
  36         /* Memory manager for CRTCs to allocate space in the display
  37          * list.  Units are dwords.
  38          */
  39 --- a/drivers/gpu/drm/vc4/vc4_hvs.c
  40 +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
  41 @@ -19,6 +19,7 @@
  42   * each CRTC.
  43   */
  44
  45 +#include <linux/clk.h>
  46  #include <linux/component.h>
  47  #include <linux/platform_device.h>
  48
  49 @@ -239,6 +240,12 @@ static int vc4_hvs_bind(struct device *d
  50         hvs->regset.regs = hvs_regs;
  51         hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
  52
  53 +       hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
  54 +       if (IS_ERR(hvs->core_clk)) {
  55 +               dev_err(&pdev->dev, "Couldn't get core clock\n");
  56 +               return PTR_ERR(hvs->regs);
  57 +       }
  58 +
  59         hvs_version = readl(hvs->regs + SCALER_DISPLSTAT) >> 24;
  60         if (hvs_version >= 0x40)
  61                 hvs->hvs5 = true;
  62 --- a/drivers/gpu/drm/vc4/vc4_kms.c
  63 +++ b/drivers/gpu/drm/vc4/vc4_kms.c
  64 @@ -13,6 +13,7 @@
  65
  66  #include <linux/bitfield.h>
  67  #include <linux/bitops.h>
  68 +#include <linux/clk.h>
  69
  70  #include <drm/drm_atomic.h>
  71  #include <drm/drm_atomic_helper.h>
  72 @@ -222,6 +223,7 @@ vc4_atomic_complete_commit(struct drm_at
  73  {
  74         struct drm_device *dev = state->dev;
  75         struct vc4_dev *vc4 = to_vc4_dev(dev);
  76 +       struct vc4_hvs *hvs = vc4->hvs;
  77         struct vc4_crtc *vc4_crtc;
  78         int i;
  79
  80 @@ -237,6 +239,8 @@ vc4_atomic_complete_commit(struct drm_at
  81                 vc4_hvs_mask_underrun(dev, vc4_crtc_state->assigned_channel);
  82         }
  83
  84 +       clk_set_rate(hvs->core_clk, 500000000);
  85 +
  86         drm_atomic_helper_wait_for_fences(dev, state, false);
  87
  88         drm_atomic_helper_wait_for_dependencies(state);
  89 @@ -262,6 +266,8 @@ vc4_atomic_complete_commit(struct drm_at
  90
  91         drm_atomic_helper_commit_cleanup_done(state);
  92
  93 +       clk_set_rate(hvs->core_clk, 200000000);
  94 +
  95         drm_atomic_state_put(state);
  96
  97         up(&vc4->async_modeset);