1 From 3e6b687bae81bdf5a430ffaa04aa04ee195a866c 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 610/806] drm/v3d: Clock V3D down when not in use.
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.
9 Signed-off-by: Eric Anholt <eric@anholt.net>
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 | 49 +++++++++++++++++++++++++++++++++++
14 3 files changed, 73 insertions(+)
16 --- a/drivers/gpu/drm/v3d/v3d_drv.c
17 +++ b/drivers/gpu/drm/v3d/v3d_drv.c
18 @@ -297,6 +297,21 @@ static int v3d_platform_drm_probe(struct
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");
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.
34 + v3d->clk_down_rate =
35 + (clk_get_rate(clk_get_parent(v3d->clk)) / (1 << 4)) + 10000;
38 ret = map_regs(v3d, &v3d->gca_regs, "gca");
40 @@ -331,6 +346,9 @@ static int v3d_platform_drm_probe(struct
44 + ret = clk_set_rate(v3d->clk, v3d->clk_down_rate);
45 + WARN_ON_ONCE(ret != 0);
50 --- a/drivers/gpu/drm/v3d/v3d_drv.h
51 +++ b/drivers/gpu/drm/v3d/v3d_drv.h
52 @@ -45,6 +45,12 @@ struct v3d_dev {
53 void __iomem *bridge_regs;
54 void __iomem *gca_regs;
56 + struct delayed_work clk_down_work;
57 + unsigned long clk_up_rate, clk_down_rate;
58 + struct mutex clk_lock;
62 struct reset_control *reset;
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
70 #include <drm/drm_syncobj.h>
71 +#include <linux/clk.h>
72 #include <linux/module.h>
73 #include <linux/platform_device.h>
74 #include <linux/pm_runtime.h>
76 #include "v3d_trace.h"
79 +v3d_clock_down_work(struct work_struct *work)
81 + struct v3d_dev *v3d =
82 + container_of(work, struct v3d_dev, clk_down_work.work);
85 + ret = clk_set_rate(v3d->clk, v3d->clk_down_rate);
86 + v3d->clk_up = false;
87 + WARN_ON_ONCE(ret != 0);
91 +v3d_clock_up_get(struct v3d_dev *v3d)
93 + mutex_lock(&v3d->clk_lock);
94 + if (v3d->clk_refcount++ == 0) {
95 + cancel_delayed_work_sync(&v3d->clk_down_work);
99 + ret = clk_set_rate(v3d->clk, v3d->clk_up_rate);
100 + WARN_ON_ONCE(ret != 0);
101 + v3d->clk_up = true;
104 + mutex_unlock(&v3d->clk_lock);
108 +v3d_clock_up_put(struct v3d_dev *v3d)
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));
115 + mutex_unlock(&v3d->clk_lock);
120 v3d_init_core(struct v3d_dev *v3d, int core)
122 /* Set OVRTMUOUT, which means that the texture sampler uniform
123 @@ -490,6 +532,7 @@ static void
124 v3d_job_free(struct kref *ref)
126 struct v3d_job *job = container_of(ref, struct v3d_job, refcount);
127 + struct v3d_dev *v3d = job->v3d;
130 for (i = 0; i < job->bo_count; i++) {
131 @@ -505,6 +548,8 @@ v3d_job_free(struct kref *ref)
132 dma_fence_put(job->irq_fence);
133 dma_fence_put(job->done_fence);
135 + v3d_clock_up_put(v3d);
140 @@ -596,6 +641,7 @@ v3d_job_init(struct v3d_dev *v3d, struct
144 + v3d_clock_up_get(v3d);
145 kref_init(&job->refcount);
148 @@ -963,6 +1009,9 @@ v3d_gem_init(struct drm_device *dev)
149 mutex_init(&v3d->sched_lock);
150 mutex_init(&v3d->cache_clean_lock);
152 + mutex_init(&v3d->clk_lock);
153 + INIT_DELAYED_WORK(&v3d->clk_down_work, v3d_clock_down_work);
155 /* Note: We don't allocate address 0. Various bits of HW
156 * treat 0 as special, such as the occlusion query counters
157 * where 0 means "disabled".