gpu: host1x: Add initial runtime PM and OPP support

Add runtime PM and OPP support to the Host1x driver. For the starter we
will keep host1x always-on because dynamic power management require a major
refactoring of the driver code since lot's of code paths are missing the
RPM handling and we're going to remove some of these paths in the future.

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>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 123 insertions, 27 deletions

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 3d4cabdbc78d..14c1ea7506fb 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -6,14 +6,18 @@
  */
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
+#include <soc/tegra/common.h>
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/host1x.h>
 #undef CREATE_TRACE_POINTS
@@ -208,6 +212,9 @@ static void host1x_setup_sid_table(struct host1x *host)
 	const struct host1x_info *info = host->info;
 	unsigned int i;
 
+	if (!info->has_hypervisor)
+		return;
+
 	for (i = 0; i < info->num_sid_entries; i++) {
 		const struct host1x_sid_entry *entry = &info->sid_table[i];
 
@@ -365,6 +372,27 @@ static void host1x_iommu_exit(struct host1x *host)
 	}
 }
 
+static int host1x_get_resets(struct host1x *host)
+{
+	int err;
+
+	host->resets[0].id = "mc";
+	host->resets[1].id = "host1x";
+	host->nresets = ARRAY_SIZE(host->resets);
+
+	err = devm_reset_control_bulk_get_optional_exclusive_released(
+				host->dev, host->nresets, host->resets);
+	if (err) {
+		dev_err(host->dev, "failed to get reset: %d\n", err);
+		return err;
+	}
+
+	if (WARN_ON(!host->resets[1].rstc))
+		return -ENOENT;
+
+	return 0;
+}
+
 static int host1x_probe(struct platform_device *pdev)
 {
 	struct host1x *host;
@@ -442,12 +470,9 @@ static int host1x_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	host->rst = devm_reset_control_get(&pdev->dev, "host1x");
-	if (IS_ERR(host->rst)) {
-		err = PTR_ERR(host->rst);
-		dev_err(&pdev->dev, "failed to get reset: %d\n", err);
+	err = host1x_get_resets(host);
+	if (err)
 		return err;
-	}
 
 	err = host1x_iommu_init(host);
 	if (err < 0) {
@@ -462,22 +487,10 @@ static int host1x_probe(struct platform_device *pdev)
 		goto iommu_exit;
 	}
 
-	err = clk_prepare_enable(host->clk);
-	if (err < 0) {
-		dev_err(&pdev->dev, "failed to enable clock\n");
-		goto free_channels;
-	}
-
-	err = reset_control_deassert(host->rst);
-	if (err < 0) {
-		dev_err(&pdev->dev, "failed to deassert reset: %d\n", err);
-		goto unprepare_disable;
-	}
-
 	err = host1x_syncpt_init(host);
 	if (err) {
 		dev_err(&pdev->dev, "failed to initialize syncpts\n");
-		goto reset_assert;
+		goto free_channels;
 	}
 
 	err = host1x_intr_init(host, syncpt_irq);
@@ -486,10 +499,18 @@ static int host1x_probe(struct platform_device *pdev)
 		goto deinit_syncpt;
 	}
 
-	host1x_debug_init(host);
+	pm_runtime_enable(&pdev->dev);
+
+	err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
+	if (err)
+		goto pm_disable;
 
-	if (host->info->has_hypervisor)
-		host1x_setup_sid_table(host);
+	/* the driver's code isn't ready yet for the dynamic RPM */
+	err = pm_runtime_resume_and_get(&pdev->dev);
+	if (err)
+		goto pm_disable;
+
+	host1x_debug_init(host);
 
 	err = host1x_register(host);
 	if (err < 0)
@@ -505,13 +526,14 @@ unregister:
 	host1x_unregister(host);
 deinit_debugfs:
 	host1x_debug_deinit(host);
+
+	pm_runtime_put_sync_suspend(&pdev->dev);
+pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
 	host1x_intr_deinit(host);
 deinit_syncpt:
 	host1x_syncpt_deinit(host);
-reset_assert:
-	reset_control_assert(host->rst);
-unprepare_disable:
-	clk_disable_unprepare(host->clk);
 free_channels:
 	host1x_channel_list_free(&host->channel_list);
 iommu_exit:
@@ -526,20 +548,94 @@ static int host1x_remove(struct platform_device *pdev)
 
 	host1x_unregister(host);
 	host1x_debug_deinit(host);
+
+	pm_runtime_force_suspend(&pdev->dev);
+
 	host1x_intr_deinit(host);
 	host1x_syncpt_deinit(host);
-	reset_control_assert(host->rst);
-	clk_disable_unprepare(host->clk);
 	host1x_iommu_exit(host);
 	host1x_bo_cache_destroy(&host->cache);
 
 	return 0;
 }
 
+static int __maybe_unused host1x_runtime_suspend(struct device *dev)
+{
+	struct host1x *host = dev_get_drvdata(dev);
+	int err;
+
+	host1x_intr_stop(host);
+	host1x_syncpt_save(host);
+
+	err = reset_control_bulk_assert(host->nresets, host->resets);
+	if (err) {
+		dev_err(dev, "failed to assert reset: %d\n", err);
+		goto resume_host1x;
+	}
+
+	usleep_range(1000, 2000);
+
+	clk_disable_unprepare(host->clk);
+	reset_control_bulk_release(host->nresets, host->resets);
+
+	return 0;
+
+resume_host1x:
+	host1x_setup_sid_table(host);
+	host1x_syncpt_restore(host);
+	host1x_intr_start(host);
+
+	return err;
+}
+
+static int __maybe_unused host1x_runtime_resume(struct device *dev)
+{
+	struct host1x *host = dev_get_drvdata(dev);
+	int err;
+
+	err = reset_control_bulk_acquire(host->nresets, host->resets);
+	if (err) {
+		dev_err(dev, "failed to acquire reset: %d\n", err);
+		return err;
+	}
+
+	err = clk_prepare_enable(host->clk);
+	if (err) {
+		dev_err(dev, "failed to enable clock: %d\n", err);
+		goto release_reset;
+	}
+
+	err = reset_control_bulk_deassert(host->nresets, host->resets);
+	if (err < 0) {
+		dev_err(dev, "failed to deassert reset: %d\n", err);
+		goto disable_clk;
+	}
+
+	host1x_setup_sid_table(host);
+	host1x_syncpt_restore(host);
+	host1x_intr_start(host);
+
+	return 0;
+
+disable_clk:
+	clk_disable_unprepare(host->clk);
+release_reset:
+	reset_control_bulk_release(host->nresets, host->resets);
+
+	return err;
+}
+
+static const struct dev_pm_ops host1x_pm_ops = {
+	SET_RUNTIME_PM_OPS(host1x_runtime_suspend, host1x_runtime_resume,
+			   NULL)
+	/* TODO: add system suspend-resume once driver will be ready for that */
+};
+
 static struct platform_driver tegra_host1x_driver = {
 	.driver = {
 		.name = "tegra-host1x",
 		.of_match_table = host1x_of_match,
+		.pm = &host1x_pm_ops,
 	},
 	.probe = host1x_probe,
 	.remove = host1x_remove,