[PATCH v6 3/6] drm/msm/dpu: Use OPP API to set clk/perf state

Rajendra Nayak
2020-06-15T12:04:06Z

On some qualcomm platforms DPU needs to express a performance state
requirement on a power domain depending on the clock rates.
Use OPP table from DT to register with OPP framework and use
dev_pm_opp_set_rate() to set the clk/perf state.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: dri-devel@lists.freedesktop.org
---
No functional change in v6, rebased over 5.8-rc1

drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c | 3 ++-
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 26 +++++++++++++++++++++++++-
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h | 4 ++++
3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
index 7c230f7..b36919d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
@@ -7,6 +7,7 @@
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/mutex.h>
+#include <linux/pm_opp.h>
#include <linux/sort.h>
#include <linux/clk.h>
#include <linux/bitmap.h>
@@ -218,7 +219,7 @@ static int _dpu_core_perf_set_core_clk_rate(struct dpu_kms *kms, u64 rate)
rate = core_clk->max_rate;

core_clk->rate = rate;
- return msm_dss_clk_set_rate(core_clk, 1);
+ return dev_pm_opp_set_rate(&kms->pdev->dev, core_clk->rate);
}

static u64 _dpu_core_perf_get_core_clk_rate(struct dpu_kms *kms)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index b8615d4..0bc8ec4 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -10,6 +10,7 @@
#include <linux/debugfs.h>
#include <linux/dma-buf.h>
#include <linux/of_irq.h>
+#include <linux/pm_opp.h>

#include <drm/drm_crtc.h>
#include <drm/drm_file.h>
@@ -1025,11 +1026,23 @@ static int dpu_bind(struct device *dev, struct device *master, void *data)
if (!dpu_kms)
return -ENOMEM;

+ dpu_kms->opp_table = dev_pm_opp_set_clkname(dev, "core");
+ if (IS_ERR(dpu_kms->opp_table))
+ return PTR_ERR(dpu_kms->opp_table);
+ /* OPP table is optional */
+ ret = dev_pm_opp_of_add_table(dev);
+ if (!ret) {
+ dpu_kms->has_opp_table = true;
+ } else if (ret != -ENODEV) {
+ dev_err(dev, "invalid OPP table in device tree\n");
+ return ret;
+ }
+
mp = &dpu_kms->mp;
ret = msm_dss_parse_clock(pdev, mp);
if (ret) {
DPU_ERROR("failed to parse clocks, ret=%d\n", ret);
- return ret;
+ goto err;
}

platform_set_drvdata(pdev, dpu_kms);
@@ -1043,6 +1056,11 @@ static int dpu_bind(struct device *dev, struct device *master, void *data)

priv->kms = &dpu_kms->base;
return ret;
+err:
+ if (dpu_kms->has_opp_table)
+ dev_pm_opp_of_remove_table(dev);
+ dev_pm_opp_put_clkname(dpu_kms->opp_table);
+ return ret;
}

static void dpu_unbind(struct device *dev, struct device *master, void *data)
@@ -1057,6 +1075,10 @@ static void dpu_unbind(struct device *dev, struct device *master, void *data)

if (dpu_kms->rpm_enabled)
pm_runtime_disable(&pdev->dev);
+
+ if (dpu_kms->has_opp_table)
+ dev_pm_opp_of_remove_table(dev);
+ dev_pm_opp_put_clkname(dpu_kms->opp_table);
}

static const struct component_ops dpu_ops = {
@@ -1082,6 +1104,8 @@ static int __maybe_unused dpu_runtime_suspend(struct device *dev)
struct dpu_kms *dpu_kms = platform_get_drvdata(pdev);
struct dss_module_power *mp = &dpu_kms->mp;

+ /* Drop the performance state vote */
+ dev_pm_opp_set_rate(dev, 0);
rc = msm_dss_enable_clk(mp->clk_config, mp->num_clk, false);
if (rc)
DPU_ERROR("clock disable failed rc:%d\n", rc);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
index a3b122b..7400cd7 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
@@ -128,6 +128,10 @@ struct dpu_kms {

struct platform_device *pdev;
bool rpm_enabled;
+
+ struct opp_table *opp_table;
+ bool has_opp_table;
+
struct dss_module_power mp;

/* reference count bandwidth requests, so we know when we can
--
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