[PATCH v12 13/35] drm/tegra: gr2d: Support generic power domain and runtime PM

Dmitry Osipenko
2021-09-21T02:45:09Z

Add runtime power management and support generic power domains.

Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/gpu/drm/tegra/gr2d.c | 155 +++++++++++++++++++++++++++++++++--
1 file changed, 147 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index de288cba3905..13df8f118f75 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -7,11 +7,21 @@
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+#include <soc/tegra/common.h>

#include "drm.h"
#include "gem.h"
#include "gr2d.h"

+enum {
+ RST_MC,
+ RST_GR2D,
+ RST_GR2D_MAX,
+};
+
struct gr2d_soc {
unsigned int version;
};
@@ -21,6 +31,9 @@ struct gr2d {
struct host1x_channel *channel;
struct clk *clk;

+ struct reset_control_bulk_data resets[RST_GR2D_MAX];
+ unsigned int nresets;
+
const struct gr2d_soc *soc;

DECLARE_BITMAP(addr_regs, GR2D_NUM_REGS);
@@ -101,16 +114,24 @@ static int gr2d_open_channel(struct tegra_drm_client *client,
struct tegra_drm_context *context)
{
struct gr2d *gr2d = to_gr2d(client);
+ int err;

context->channel = host1x_channel_get(gr2d->channel);
if (!context->channel)
return -ENOMEM;

+ err = pm_runtime_resume_and_get(client->base.dev);
+ if (err) {
+ host1x_channel_put(context->channel);
+ return err;
+ }
+
return 0;
}

static void gr2d_close_channel(struct tegra_drm_context *context)
{
+ pm_runtime_put_sync(context->client->base.dev);
host1x_channel_put(context->channel);
}

@@ -190,6 +211,27 @@ static const u32 gr2d_addr_regs[] = {
GR2D_VA_BASE_ADDR_SB,
};

+static int gr2d_get_resets(struct device *dev, struct gr2d *gr2d)
+{
+ int err;
+
+ gr2d->resets[RST_MC].id = "mc";
+ gr2d->resets[RST_GR2D].id = "2d";
+ gr2d->nresets = RST_GR2D_MAX;
+
+ err = devm_reset_control_bulk_get_optional_exclusive_released(
+ dev, gr2d->nresets, gr2d->resets);
+ if (err) {
+ dev_err(dev, "failed to get reset: %d\n", err);
+ return err;
+ }
+
+ if (WARN_ON(!gr2d->resets[RST_GR2D].rstc))
+ return -ENOENT;
+
+ return 0;
+}
+
static int gr2d_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -202,6 +244,8 @@ static int gr2d_probe(struct platform_device *pdev)
if (!gr2d)
return -ENOMEM;

+ platform_set_drvdata(pdev, gr2d);
+
gr2d->soc = of_device_get_match_data(dev);

syncpts = devm_kzalloc(dev, sizeof(*syncpts), GFP_KERNEL);
@@ -214,11 +258,9 @@ static int gr2d_probe(struct platform_device *pdev)
return PTR_ERR(gr2d->clk);
}

- err = clk_prepare_enable(gr2d->clk);
- if (err) {
- dev_err(dev, "cannot turn on clock\n");
+ err = gr2d_get_resets(dev, gr2d);
+ if (err)
return err;
- }

INIT_LIST_HEAD(&gr2d->client.base.list);
gr2d->client.base.ops = &gr2d_client_ops;
@@ -231,20 +273,31 @@ static int gr2d_probe(struct platform_device *pdev)
gr2d->client.version = gr2d->soc->version;
gr2d->client.ops = &gr2d_ops;

+ pm_runtime_enable(dev);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_autosuspend_delay(dev, 200);
+
+ err = devm_tegra_core_dev_init_opp_table_common(dev);
+ if (err)
+ goto disable_rpm;
+
err = host1x_client_register(&gr2d->client.base);
if (err < 0) {
dev_err(dev, "failed to register host1x client: %d\n", err);
- clk_disable_unprepare(gr2d->clk);
- return err;
+ goto disable_rpm;
}

/* initialize address register map */
for (i = 0; i < ARRAY_SIZE(gr2d_addr_regs); i++)
set_bit(gr2d_addr_regs[i], gr2d->addr_regs);

- platform_set_drvdata(pdev, gr2d);
-
return 0;
+
+disable_rpm:
+ pm_runtime_dont_use_autosuspend(dev);
+ pm_runtime_disable(dev);
+
+ return err;
}

static int gr2d_remove(struct platform_device *pdev)
@@ -259,15 +312,101 @@ static int gr2d_remove(struct platform_device *pdev)
return err;
}

+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
+ return 0;
+}
+
+static int __maybe_unused gr2d_runtime_suspend(struct device *dev)
+{
+ struct gr2d *gr2d = dev_get_drvdata(dev);
+ int err;
+
+ host1x_channel_stop(gr2d->channel);
+ reset_control_bulk_release(gr2d->nresets, gr2d->resets);
+
+ /*
+ * GR2D module shouldn't be reset while hardware is idling, otherwise
+ * host1x's cmdproc will stuck on trying to access any G2 register
+ * after reset. GR2D module could be either hot-reset or reset after
+ * power-gating of the HEG partition. Hence we will put in reset only
+ * the memory client part of the module, the HEG GENPD will take care
+ * of resetting GR2D module across power-gating.
+ *
+ * On Tegra20 there is no HEG partition, but it's okay to have
+ * undetermined h/w state since userspace is expected to reprogram
+ * the state on each job submission anyways.
+ */
+ err = reset_control_acquire(gr2d->resets[RST_MC].rstc);
+ if (err) {
+ dev_err(dev, "failed to acquire MC reset: %d\n", err);
+ goto acquire_reset;
+ }
+
+ err = reset_control_assert(gr2d->resets[RST_MC].rstc);
+ reset_control_release(gr2d->resets[RST_MC].rstc);
+ if (err) {
+ dev_err(dev, "failed to assert MC reset: %d\n", err);
+ goto acquire_reset;
+ }
+
clk_disable_unprepare(gr2d->clk);

return 0;
+
+acquire_reset:
+ reset_control_bulk_acquire(gr2d->nresets, gr2d->resets);
+ reset_control_bulk_deassert(gr2d->nresets, gr2d->resets);
+
+ return err;
}

+static int __maybe_unused gr2d_runtime_resume(struct device *dev)
+{
+ struct gr2d *gr2d = dev_get_drvdata(dev);
+ int err;
+
+ err = reset_control_bulk_acquire(gr2d->nresets, gr2d->resets);
+ if (err) {
+ dev_err(dev, "failed to acquire reset: %d\n", err);
+ return err;
+ }
+
+ err = clk_prepare_enable(gr2d->clk);
+ if (err) {
+ dev_err(dev, "failed to enable clock: %d\n", err);
+ goto release_reset;
+ }
+
+ /* this is a reset array which deasserts both 2D MC and 2D itself */
+ err = reset_control_bulk_deassert(gr2d->nresets, gr2d->resets);
+ if (err) {
+ dev_err(dev, "failed to deassert reset: %d\n", err);
+ goto disable_clk;
+ }
+
+ return 0;
+
+disable_clk:
+ clk_disable_unprepare(gr2d->clk);
+release_reset:
+ reset_control_bulk_release(gr2d->nresets, gr2d->resets);
+
+ return err;
+}
+
+static const struct dev_pm_ops tegra_gr2d_pm = {
+ SET_RUNTIME_PM_OPS(gr2d_runtime_suspend, gr2d_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+};
+
struct platform_driver tegra_gr2d_driver = {
.driver = {
.name = "tegra-gr2d",
.of_match_table = gr2d_match,
+ .pm = &tegra_gr2d_pm,
},
.probe = gr2d_probe,
.remove = gr2d_remove,
--
2.32.0