Message-Id: <20211130232347.950-14-digetx@gmail.com>
Date:   Wed,  1 Dec 2021 02:23:20 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Viresh Kumar <vireshk@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Peter De Schrijver <pdeschrijver@...dia.com>,
        Mikko Perttunen <mperttunen@...dia.com>,
        Lee Jones <lee.jones@...aro.org>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>, Nishanth Menon <nm@...com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Michael Turquette <mturquette@...libre.com>
Cc:     linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-pm@...r.kernel.org, linux-pwm@...r.kernel.org,
        linux-mmc@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-clk@...r.kernel.org, David Heidelberg <david@...t.cz>
Subject: [PATCH v16 13/40] drm/tegra: gr2d: Support generic power domain and runtime PM

Add runtime power management and support generic power domains.

Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
Tested-by: Peter Geis <pgwipeout@...il.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@...il.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@...il.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@...tonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/gpu/drm/tegra/gr2d.c | 184 ++++++++++++++++++++++++++++-------
 1 file changed, 148 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index ba3722f1b865..2382def93923 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -8,12 +8,21 @@
 #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;
 };
@@ -21,9 +30,11 @@ struct gr2d_soc {
 struct gr2d {
 	struct tegra_drm_client client;
 	struct host1x_channel *channel;
-	struct reset_control *rst;
 	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);
@@ -59,15 +70,22 @@ static int gr2d_init(struct host1x_client *client)
 		goto free;
 	}
 
+	pm_runtime_enable(client->dev);
+	pm_runtime_use_autosuspend(client->dev);
+	pm_runtime_set_autosuspend_delay(client->dev, 200);
+
 	err = tegra_drm_register_client(dev->dev_private, drm);
 	if (err < 0) {
 		dev_err(client->dev, "failed to register client: %d\n", err);
-		goto detach;
+		goto disable_rpm;
 	}
 
 	return 0;
 
-detach:
+disable_rpm:
+	pm_runtime_dont_use_autosuspend(client->dev);
+	pm_runtime_force_suspend(client->dev);
+
 	host1x_client_iommu_detach(client);
 free:
 	host1x_syncpt_put(client->syncpts[0]);
@@ -88,10 +106,15 @@ static int gr2d_exit(struct host1x_client *client)
 	if (err < 0)
 		return err;
 
+	pm_runtime_dont_use_autosuspend(client->dev);
+	pm_runtime_force_suspend(client->dev);
+
 	host1x_client_iommu_detach(client);
 	host1x_syncpt_put(client->syncpts[0]);
 	host1x_channel_put(gr2d->channel);
 
+	gr2d->channel = NULL;
+
 	return 0;
 }
 
@@ -104,10 +127,17 @@ static int gr2d_open_channel(struct tegra_drm_client *client,
 			     struct tegra_drm_context *context)
 {
 	struct gr2d *gr2d = to_gr2d(client);
+	int err;
+
+	err = pm_runtime_resume_and_get(client->base.dev);
+	if (err)
+		return err;
 
 	context->channel = host1x_channel_get(gr2d->channel);
-	if (!context->channel)
+	if (!context->channel) {
+		pm_runtime_put(client->base.dev);
 		return -ENOMEM;
+	}
 
 	return 0;
 }
@@ -115,6 +145,7 @@ static int gr2d_open_channel(struct tegra_drm_client *client,
 static void gr2d_close_channel(struct tegra_drm_context *context)
 {
 	host1x_channel_put(context->channel);
+	pm_runtime_put(context->client->base.dev);
 }
 
 static int gr2d_is_addr_reg(struct device *dev, u32 class, u32 offset)
@@ -193,6 +224,27 @@ 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;
@@ -205,37 +257,23 @@ 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);
 	if (!syncpts)
 		return -ENOMEM;
 
-	gr2d->rst = devm_reset_control_get(dev, NULL);
-	if (IS_ERR(gr2d->rst)) {
-		dev_err(dev, "cannot get reset\n");
-		return PTR_ERR(gr2d->rst);
-	}
-
 	gr2d->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(gr2d->clk)) {
 		dev_err(dev, "cannot get clock\n");
 		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;
-	}
-
-	usleep_range(2000, 4000);
-
-	err = reset_control_deassert(gr2d->rst);
-	if (err < 0) {
-		dev_err(dev, "failed to deassert reset: %d\n", err);
-		goto disable_clk;
-	}
 
 	INIT_LIST_HEAD(&gr2d->client.base.list);
 	gr2d->client.base.ops = &gr2d_client_ops;
@@ -248,26 +286,21 @@ static int gr2d_probe(struct platform_device *pdev)
 	gr2d->client.version = gr2d->soc->version;
 	gr2d->client.ops = &gr2d_ops;
 
+	err = devm_tegra_core_dev_init_opp_table_common(dev);
+	if (err)
+		return err;
+
 	err = host1x_client_register(&gr2d->client.base);
 	if (err < 0) {
 		dev_err(dev, "failed to register host1x client: %d\n", err);
-		goto assert_rst;
+		return err;
 	}
 
 	/* 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;
-
-assert_rst:
-	(void)reset_control_assert(gr2d->rst);
-disable_clk:
-	clk_disable_unprepare(gr2d->clk);
-
-	return err;
 }
 
 static int gr2d_remove(struct platform_device *pdev)
@@ -282,21 +315,100 @@ static int gr2d_remove(struct platform_device *pdev)
 		return err;
 	}
 
-	err = reset_control_assert(gr2d->rst);
-	if (err < 0)
-		dev_err(&pdev->dev, "failed to assert reset: %d\n", err);
+	return 0;
+}
 
-	usleep_range(2000, 4000);
+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;
+	}
+
+	usleep_range(2000, 4000);
+
+	/* 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,
-- 
2.33.1

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