[PATCH v7 10/37] gpu: host1x: Add runtime PM support

[Dmitry Osipenko <digetx@gmail.com>]

Add runtime PM support to the Host1x driver. This is required for enabling
system-wide DVFS and supporting dynamic power management using a generic
power domain. 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 will need the RPM handling and we're going to
remove some of these paths in the future. Host1x doesn't consume much
power so it is good enough, we at least need to resume Host1x in order
to initialize the power state.

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/host1x/debug.c         |  15 +++
 drivers/gpu/host1x/dev.c           | 145 +++++++++++++++++++++++------
 drivers/gpu/host1x/dev.h           |   3 +-
 drivers/gpu/host1x/hw/channel_hw.c |  44 ++++-----
 drivers/gpu/host1x/intr.c          |   3 -
 drivers/gpu/host1x/syncpt.c        |   5 +-
 6 files changed, 159 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/host1x/debug.c b/drivers/gpu/host1x/debug.c
index 8a14880c61bb..18d9c8d206e3 100644
--- a/drivers/gpu/host1x/debug.c
+++ b/drivers/gpu/host1x/debug.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/debugfs.h>
+#include <linux/pm_runtime.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 
@@ -52,6 +53,11 @@ static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo)
 {
 	struct host1x *m = dev_get_drvdata(ch->dev->parent);
 	struct output *o = data;
+	int err;
+
+	err = pm_runtime_resume_and_get(m->dev);
+	if (err < 0)
+		return err;
 
 	mutex_lock(&ch->cdma.lock);
 	mutex_lock(&debug_lock);
@@ -64,6 +70,8 @@ static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo)
 	mutex_unlock(&debug_lock);
 	mutex_unlock(&ch->cdma.lock);
 
+	pm_runtime_put(m->dev);
+
 	return 0;
 }
 
@@ -71,9 +79,14 @@ static void show_syncpts(struct host1x *m, struct output *o)
 {
 	struct list_head *pos;
 	unsigned int i;
+	int err;
 
 	host1x_debug_output(o, "---- syncpts ----\n");
 
+	err = pm_runtime_resume_and_get(m->dev);
+	if (err < 0)
+		return;
+
 	for (i = 0; i < host1x_syncpt_nb_pts(m); i++) {
 		u32 max = host1x_syncpt_read_max(m->syncpt + i);
 		u32 min = host1x_syncpt_load(m->syncpt + i);
@@ -101,6 +114,8 @@ static void show_syncpts(struct host1x *m, struct output *o)
 					    base_val);
 	}
 
+	pm_runtime_put(m->dev);
+
 	host1x_debug_output(o, "\n");
 }
 
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index fbb6447b8659..0945df6039af 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -6,12 +6,15 @@
  */
 
 #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_opp.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
 #define CREATE_TRACE_POINTS
@@ -190,6 +193,9 @@ 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];
 
@@ -347,6 +353,27 @@ 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 -EINVAL;
+
+	return 0;
+}
+
 static int host1x_probe(struct platform_device *pdev)
 {
 	struct host1x *host;
@@ -423,12 +450,9 @@ 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) {
@@ -443,22 +467,10 @@ 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);
@@ -467,10 +479,14 @@ static int host1x_probe(struct platform_device *pdev)
 		goto deinit_syncpt;
 	}
 
-	host1x_debug_init(host);
+	pm_runtime_enable(&pdev->dev);
+
+	/* the driver's code isn't ready yet for the dynamic RPM */
+	err = pm_runtime_resume_and_get(&pdev->dev);
+	if (err)
+		goto deinit_intr;
 
-	if (host->info->has_hypervisor)
-		host1x_setup_sid_table(host);
+	host1x_debug_init(host);
 
 	err = host1x_register(host);
 	if (err < 0)
@@ -486,13 +502,13 @@ static int host1x_probe(struct platform_device *pdev)
 	host1x_unregister(host);
 deinit_debugfs:
 	host1x_debug_deinit(host);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+deinit_intr:
 	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:
@@ -507,19 +523,94 @@ static int host1x_remove(struct platform_device *pdev)
 
 	host1x_unregister(host);
 	host1x_debug_deinit(host);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
 	host1x_intr_deinit(host);
 	host1x_syncpt_deinit(host);
-	reset_control_assert(host->rst);
-	clk_disable_unprepare(host->clk);
 	host1x_iommu_exit(host);
 
 	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 = {
+	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,
 	},
 	.probe = host1x_probe,
 	.remove = host1x_remove,
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index fa6d4bc46e98..41a7a63514c4 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -118,7 +118,8 @@ struct host1x {
 	struct host1x_syncpt_base *bases;
 	struct device *dev;
 	struct clk *clk;
-	struct reset_control *rst;
+	struct reset_control_bulk_data resets[2];
+	unsigned int nresets;
 
 	struct iommu_group *group;
 	struct iommu_domain *domain;
diff --git a/drivers/gpu/host1x/hw/channel_hw.c b/drivers/gpu/host1x/hw/channel_hw.c
index d4c28faf27d1..27290d0d7eaf 100644
--- a/drivers/gpu/host1x/hw/channel_hw.c
+++ b/drivers/gpu/host1x/hw/channel_hw.c
@@ -114,6 +114,27 @@ static void host1x_channel_set_streamid(struct host1x_channel *channel)
 #endif
 }
 
+static void host1x_enable_gather_filter(struct host1x_channel *ch)
+{
+#if HOST1X_HW >= 6
+	struct host1x *host = dev_get_drvdata(ch->dev->parent);
+	u32 val;
+
+	if (!host->hv_regs)
+		return;
+
+	val = host1x_hypervisor_readl(
+		host, HOST1X_HV_CH_KERNEL_FILTER_GBUFFER(ch->id / 32));
+	val |= BIT(ch->id % 32);
+	host1x_hypervisor_writel(
+		host, val, HOST1X_HV_CH_KERNEL_FILTER_GBUFFER(ch->id / 32));
+#elif HOST1X_HW >= 4
+	host1x_ch_writel(ch,
+			 HOST1X_CHANNEL_CHANNELCTRL_KERNEL_FILTER_GBUFFER(1),
+			 HOST1X_CHANNEL_CHANNELCTRL);
+#endif
+}
+
 static int channel_submit(struct host1x_job *job)
 {
 	struct host1x_channel *ch = job->channel;
@@ -145,6 +166,7 @@ static int channel_submit(struct host1x_job *job)
 	}
 
 	host1x_channel_set_streamid(ch);
+	host1x_enable_gather_filter(ch);
 
 	/* begin a CDMA submit */
 	err = host1x_cdma_begin(&ch->cdma, job);
@@ -204,27 +226,6 @@ static int channel_submit(struct host1x_job *job)
 	return err;
 }
 
-static void enable_gather_filter(struct host1x *host,
-				 struct host1x_channel *ch)
-{
-#if HOST1X_HW >= 6
-	u32 val;
-
-	if (!host->hv_regs)
-		return;
-
-	val = host1x_hypervisor_readl(
-		host, HOST1X_HV_CH_KERNEL_FILTER_GBUFFER(ch->id / 32));
-	val |= BIT(ch->id % 32);
-	host1x_hypervisor_writel(
-		host, val, HOST1X_HV_CH_KERNEL_FILTER_GBUFFER(ch->id / 32));
-#elif HOST1X_HW >= 4
-	host1x_ch_writel(ch,
-			 HOST1X_CHANNEL_CHANNELCTRL_KERNEL_FILTER_GBUFFER(1),
-			 HOST1X_CHANNEL_CHANNELCTRL);
-#endif
-}
-
 static int host1x_channel_init(struct host1x_channel *ch, struct host1x *dev,
 			       unsigned int index)
 {
@@ -233,7 +234,6 @@ static int host1x_channel_init(struct host1x_channel *ch, struct host1x *dev,
 #else
 	ch->regs = dev->regs + index * 0x100;
 #endif
-	enable_gather_filter(dev, ch);
 	return 0;
 }
 
diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c
index 6d1f3c0fdbe7..1600de3ccceb 100644
--- a/drivers/gpu/host1x/intr.c
+++ b/drivers/gpu/host1x/intr.c
@@ -288,14 +288,11 @@ int host1x_intr_init(struct host1x *host, unsigned int irq_sync)
 			 "host1x_sp_%02u", id);
 	}
 
-	host1x_intr_start(host);
-
 	return 0;
 }
 
 void host1x_intr_deinit(struct host1x *host)
 {
-	host1x_intr_stop(host);
 }
 
 void host1x_intr_start(struct host1x *host)
diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
index e648ebbb2027..b5ca3fdf33b2 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -143,6 +143,8 @@ void host1x_syncpt_restore(struct host1x *host)
 	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 		host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 
+	host1x_hw_syncpt_enable_protection(host);
+
 	wmb();
 }
 
@@ -366,9 +368,6 @@ int host1x_syncpt_init(struct host1x *host)
 	host->syncpt = syncpt;
 	host->bases = bases;
 
-	host1x_syncpt_restore(host);
-	host1x_hw_syncpt_enable_protection(host);
-
 	/* Allocate sync point to use for clearing waits for expired fences */
 	host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
 	if (!host->nop_sp)
-- 
2.30.2