diff mbox series

[v15,12/39] drm/tegra: gr2d: Support generic power domain and runtime PM

Message ID 20211114193435.7705-13-digetx@gmail.com (mailing list archive)
State New, archived
Headers show
Series NVIDIA Tegra power management patches for 5.17 | expand

Commit Message

Dmitry Osipenko Nov. 14, 2021, 7:34 p.m. UTC
Add runtime power management and support generic power domains.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
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 | 184 ++++++++++++++++++++++++++++-------
 1 file changed, 148 insertions(+), 36 deletions(-)

Comments

Michał Mirosław Nov. 28, 2021, 5:47 a.m. UTC | #1
On Sun, Nov 14, 2021 at 10:34:08PM +0300, Dmitry Osipenko wrote:
> Add runtime power management and support generic power domains.
[...]
> @@ -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(context->client->base.dev);

Could host1x_channel_get/put() handle pm_runtime* calls ? I would expect
this to be common code for the users.

BTW, pm_runtime_resume_and_get() uses different dev than
pm_runtime_put() in the error path - is this intended?

Best Regards
Michał Mirosław
Dmitry Osipenko Nov. 28, 2021, 9:50 p.m. UTC | #2
28.11.2021 08:47, Michał Mirosław пишет:
> On Sun, Nov 14, 2021 at 10:34:08PM +0300, Dmitry Osipenko wrote:
>> Add runtime power management and support generic power domains.
> [...]
>> @@ -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(context->client->base.dev);
> 
> Could host1x_channel_get/put() handle pm_runtime* calls ? I would expect
> this to be common code for the users.

We already have host1x code that manages runtime PM of the client
drivers, but it does that only for the code path of the new UAPI.

In case of the older UAPI, seems we can move the RPM get/put into
tegra/drm.c. I'll consider that change for v16, thank you.

> BTW, pm_runtime_resume_and_get() uses different dev than
> pm_runtime_put() in the error path - is this intended?

These functions use the same dev. The context->client is redundant
there, good catch.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index ba3722f1b865..b4cd7655b3dc 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(context->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,