target/linux/bcm27xx/patches-5.4/950-0273-drm-v3d-Clock-V3D-down-when-not-in-use.patch

   1 From ca8579839f0ebf0ffe73d1135284363b2155e712 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Thu, 2 May 2019 13:22:53 -0700
   4 Subject: [PATCH] drm/v3d: Clock V3D down when not in use.
   5
   6 My various attempts at re-enabling runtime PM have failed, so just
   7 crank the clock down when V3D is idle to reduce power consumption.
   8
   9 Signed-off-by: Eric Anholt <eric@anholt.net>
  10 ---
  11  drivers/gpu/drm/v3d/v3d_drv.c | 18 ++++++++++++
  12  drivers/gpu/drm/v3d/v3d_drv.h |  6 ++++
  13  drivers/gpu/drm/v3d/v3d_gem.c | 53 +++++++++++++++++++++++++++++++----
  14  3 files changed, 72 insertions(+), 5 deletions(-)
  15
  16 --- a/drivers/gpu/drm/v3d/v3d_drv.c
  17 +++ b/drivers/gpu/drm/v3d/v3d_drv.c
  18 @@ -282,6 +282,21 @@ static int v3d_platform_drm_probe(struct
  19                 }
  20         }
  21
  22 +       v3d->clk = devm_clk_get(dev, NULL);
  23 +       if (IS_ERR(v3d->clk)) {
  24 +               if (ret != -EPROBE_DEFER)
  25 +                       dev_err(dev, "Failed to get clock\n");
  26 +               goto dev_free;
  27 +       }
  28 +       v3d->clk_up_rate = clk_get_rate(v3d->clk);
  29 +       /* For downclocking, drop it to the minimum frequency we can get from
  30 +        * the CPRMAN clock generator dividing off our parent.  The divider is
  31 +        * 4 bits, but ask for just higher than that so that rounding doesn't
  32 +        * make cprman reject our rate.
  33 +        */
  34 +       v3d->clk_down_rate =
  35 +               (clk_get_rate(clk_get_parent(v3d->clk)) / (1 << 4)) + 10000;
  36 +
  37         if (v3d->ver < 41) {
  38                 ret = map_regs(v3d, &v3d->gca_regs, "gca");
  39                 if (ret)
  40 @@ -316,6 +331,9 @@ static int v3d_platform_drm_probe(struct
  41         if (ret)
  42                 goto irq_disable;
  43
  44 +       ret = clk_set_rate(v3d->clk, v3d->clk_down_rate);
  45 +       WARN_ON_ONCE(ret != 0);
  46 +
  47         return 0;
  48
  49  irq_disable:
  50 --- a/drivers/gpu/drm/v3d/v3d_drv.h
  51 +++ b/drivers/gpu/drm/v3d/v3d_drv.h
  52 @@ -54,6 +54,12 @@ struct v3d_dev {
  53         void __iomem *bridge_regs;
  54         void __iomem *gca_regs;
  55         struct clk *clk;
  56 +       struct delayed_work clk_down_work;
  57 +       unsigned long clk_up_rate, clk_down_rate;
  58 +       struct mutex clk_lock;
  59 +       u32 clk_refcount;
  60 +       bool clk_up;
  61 +
  62         struct reset_control *reset;
  63
  64         /* Virtual and DMA addresses of the single shared page table. */
  65 --- a/drivers/gpu/drm/v3d/v3d_gem.c
  66 +++ b/drivers/gpu/drm/v3d/v3d_gem.c
  67 @@ -4,6 +4,7 @@
  68  #include <linux/device.h>
  69  #include <linux/dma-mapping.h>
  70  #include <linux/io.h>
  71 +#include <linux/clk.h>
  72  #include <linux/module.h>
  73  #include <linux/platform_device.h>
  74  #include <linux/pm_runtime.h>
  75 @@ -19,6 +20,47 @@
  76  #include "v3d_trace.h"
  77
  78  static void
  79 +v3d_clock_down_work(struct work_struct *work)
  80 +{
  81 +       struct v3d_dev *v3d =
  82 +               container_of(work, struct v3d_dev, clk_down_work.work);
  83 +       int ret;
  84 +
  85 +       ret = clk_set_rate(v3d->clk, v3d->clk_down_rate);
  86 +       v3d->clk_up = false;
  87 +       WARN_ON_ONCE(ret != 0);
  88 +}
  89 +
  90 +static void
  91 +v3d_clock_up_get(struct v3d_dev *v3d)
  92 +{
  93 +       mutex_lock(&v3d->clk_lock);
  94 +       if (v3d->clk_refcount++ == 0) {
  95 +               cancel_delayed_work_sync(&v3d->clk_down_work);
  96 +               if (!v3d->clk_up)  {
  97 +                       int ret;
  98 +
  99 +                       ret = clk_set_rate(v3d->clk, v3d->clk_up_rate);
 100 +                       WARN_ON_ONCE(ret != 0);
 101 +                       v3d->clk_up = true;
 102 +               }
 103 +       }
 104 +       mutex_unlock(&v3d->clk_lock);
 105 +}
 106 +
 107 +static void
 108 +v3d_clock_up_put(struct v3d_dev *v3d)
 109 +{
 110 +       mutex_lock(&v3d->clk_lock);
 111 +       if (--v3d->clk_refcount == 0) {
 112 +               schedule_delayed_work(&v3d->clk_down_work,
 113 +                                     msecs_to_jiffies(100));
 114 +       }
 115 +       mutex_unlock(&v3d->clk_lock);
 116 +}
 117 +
 118 +
 119 +static void
 120  v3d_init_core(struct v3d_dev *v3d, int core)
 121  {
 122         /* Set OVRTMUOUT, which means that the texture sampler uniform
 123 @@ -354,6 +396,7 @@ v3d_job_free(struct kref *ref)
 124         struct v3d_job *job = container_of(ref, struct v3d_job, refcount);
 125         unsigned long index;
 126         struct dma_fence *fence;
 127 +       struct v3d_dev *v3d = job->v3d;
 128         int i;
 129
 130         for (i = 0; i < job->bo_count; i++) {
 131 @@ -367,11 +410,7 @@ v3d_job_free(struct kref *ref)
 132         }
 133         xa_destroy(&job->deps);
 134
 135 -       dma_fence_put(job->irq_fence);
 136 -       dma_fence_put(job->done_fence);
 137 -
 138 -       pm_runtime_mark_last_busy(job->v3d->dev);
 139 -       pm_runtime_put_autosuspend(job->v3d->dev);
 140 +       v3d_clock_up_put(v3d);
 141
 142         kfree(job);
 143  }
 144 @@ -453,6 +492,7 @@ v3d_job_init(struct v3d_dev *v3d, struct
 145         if (ret)
 146                 goto fail;
 147
 148 +       v3d_clock_up_get(v3d);
 149         kref_init(&job->refcount);
 150
 151         return 0;
 152 @@ -841,6 +881,9 @@ v3d_gem_init(struct drm_device *dev)
 153         mutex_init(&v3d->sched_lock);
 154         mutex_init(&v3d->cache_clean_lock);
 155
 156 +       mutex_init(&v3d->clk_lock);
 157 +       INIT_DELAYED_WORK(&v3d->clk_down_work, v3d_clock_down_work);
 158 +
 159         /* Note: We don't allocate address 0.  Various bits of HW
 160          * treat 0 as special, such as the occlusion query counters
 161          * where 0 means "disabled".