[PATCH v1 0/4] Tegra FUSE clock improvements for 5.15

[PATCH v1 0/4] Tegra FUSE clock improvements for 5.15

[Dmitry Osipenko]

Hello,

This series improves handling of the FUSE clock by keeping it enabled only
when necessary.

Dmitry Osipenko (4):
  soc/tegra: fuse: Clear fuse->clk on driver probe failure
  soc/tegra: fuse: Add runtime PM support
  soc/tegra: fuse: Enable fuse clock on suspend for Tegra124
  clk: tegra: Remove CLK_IS_CRITICAL flag from fuse clock

 drivers/clk/tegra/clk-tegra-periph.c  |  6 +--
 drivers/soc/tegra/fuse/fuse-tegra.c   | 60 +++++++++++++++++++++++++++
 drivers/soc/tegra/fuse/fuse-tegra20.c | 11 +++--
 drivers/soc/tegra/fuse/fuse-tegra30.c | 16 ++++---
 drivers/soc/tegra/fuse/fuse.h         |  2 +
 5 files changed, 81 insertions(+), 14 deletions(-)

-- 
2.32.0

[PATCH v1 1/4] soc/tegra: fuse: Clear fuse->clk on driver probe failure

[Dmitry Osipenko]

The fuse->clk must be cleared if FUSE driver fails to probe, otherwise
tegra_fuse_readl() will crash. It's unlikely to happen in practice,
nevertheless let's correct it for completeness.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/soc/tegra/fuse/fuse-tegra.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index 3d9da3d359da..2434c570b53c 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -246,6 +246,7 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 	return 0;
 
 restore:
+	fuse->clk = NULL;
 	fuse->base = base;
 	return err;
 }
-- 
2.32.0

[PATCH v1 2/4] soc/tegra: fuse: Add runtime PM support

[Dmitry Osipenko]

The Tegra FUSE belongs to the core power domain and we're going to enable
GENPD support for the core domain. Now FUSE device must be resumed using
runtime PM API in order to initialize the FUSE power state. Add runtime PM
support to the FUSE driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 30 +++++++++++++++++++++++++++
 drivers/soc/tegra/fuse/fuse-tegra20.c | 10 +++++----
 drivers/soc/tegra/fuse/fuse-tegra30.c |  9 ++++----
 3 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index 2434c570b53c..747237865aff 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -13,6 +13,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
 
@@ -210,6 +211,8 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, fuse);
 	fuse->dev = &pdev->dev;
 
+	pm_runtime_enable(&pdev->dev);
+
 	if (fuse->soc->probe) {
 		err = fuse->soc->probe(fuse);
 		if (err < 0)
@@ -248,13 +251,40 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 restore:
 	fuse->clk = NULL;
 	fuse->base = base;
+	pm_runtime_disable(&pdev->dev);
 	return err;
 }
 
+static int __maybe_unused tegra_fuse_runtime_resume(struct device *dev)
+{
+	int err;
+
+	err = clk_prepare_enable(fuse->clk);
+	if (err < 0) {
+		dev_err(dev, "failed to enable FUSE clock: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused tegra_fuse_runtime_suspend(struct device *dev)
+{
+	clk_disable_unprepare(fuse->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tegra_fuse_pm = {
+	SET_RUNTIME_PM_OPS(tegra_fuse_runtime_suspend, tegra_fuse_runtime_resume,
+			   NULL)
+};
+
 static struct platform_driver tegra_fuse_driver = {
 	.driver = {
 		.name = "tegra-fuse",
 		.of_match_table = tegra_fuse_match,
+		.pm = &tegra_fuse_pm,
 		.suppress_bind_attrs = true,
 	},
 	.probe = tegra_fuse_probe,
diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c
index 16aaa28573ac..cd6a273707fe 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra20.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra20.c
@@ -16,6 +16,7 @@
 #include <linux/kobject.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/random.h>
 
 #include <soc/tegra/fuse.h>
@@ -46,6 +47,10 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	u32 value = 0;
 	int err;
 
+	err = pm_runtime_resume_and_get(fuse->dev);
+	if (err)
+		return err;
+
 	mutex_lock(&fuse->apbdma.lock);
 
 	fuse->apbdma.config.src_addr = fuse->phys + FUSE_BEGIN + offset;
@@ -66,8 +71,6 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 
 	reinit_completion(&fuse->apbdma.wait);
 
-	clk_prepare_enable(fuse->clk);
-
 	dmaengine_submit(dma_desc);
 	dma_async_issue_pending(fuse->apbdma.chan);
 	time_left = wait_for_completion_timeout(&fuse->apbdma.wait,
@@ -78,10 +81,9 @@ static u32 tegra20_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	else
 		value = *fuse->apbdma.virt;
 
-	clk_disable_unprepare(fuse->clk);
-
 out:
 	mutex_unlock(&fuse->apbdma.lock);
+	pm_runtime_put(fuse->dev);
 	return value;
 }
 
diff --git a/drivers/soc/tegra/fuse/fuse-tegra30.c b/drivers/soc/tegra/fuse/fuse-tegra30.c
index c1aa7815bd6e..dd03565a39a4 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra30.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra30.c
@@ -12,6 +12,7 @@
 #include <linux/of_device.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/random.h>
 
 #include <soc/tegra/fuse.h>
@@ -52,15 +53,13 @@ static u32 tegra30_fuse_read(struct tegra_fuse *fuse, unsigned int offset)
 	u32 value;
 	int err;
 
-	err = clk_prepare_enable(fuse->clk);
-	if (err < 0) {
-		dev_err(fuse->dev, "failed to enable FUSE clock: %d\n", err);
+	err = pm_runtime_resume_and_get(fuse->dev);
+	if (err)
 		return 0;
-	}
 
 	value = readl_relaxed(fuse->base + FUSE_BEGIN + offset);
 
-	clk_disable_unprepare(fuse->clk);
+	pm_runtime_put(fuse->dev);
 
 	return value;
 }
-- 
2.32.0

[PATCH v1 3/4] soc/tegra: fuse: Enable fuse clock on suspend for Tegra124

[Dmitry Osipenko]

The FUSE clock should be enabled during suspend on Tegra124. Currently
clk driver enables it on all SoCs, but FUSE may require a higher core
voltage on Tegra30 while enabled. Move the quirk into the FUSE driver
and make it specific to Tegra124.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/soc/tegra/fuse/fuse-tegra.c   | 29 +++++++++++++++++++++++++++
 drivers/soc/tegra/fuse/fuse-tegra20.c |  1 +
 drivers/soc/tegra/fuse/fuse-tegra30.c |  7 +++++++
 drivers/soc/tegra/fuse/fuse.h         |  2 ++
 4 files changed, 39 insertions(+)

diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index 747237865aff..f2151815db58 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -275,9 +275,38 @@ static int __maybe_unused tegra_fuse_runtime_suspend(struct device *dev)
 	return 0;
 }
 
+static int __maybe_unused tegra_fuse_suspend(struct device *dev)
+{
+	int ret;
+
+	/*
+	 * Critical for RAM re-repair operation, which must occur on resume
+	 * from LP1 system suspend and as part of CCPLEX cluster switching.
+	 */
+	if (fuse->soc->clk_suspend_on)
+		ret = pm_runtime_resume_and_get(dev);
+	else
+		ret = pm_runtime_force_suspend(dev);
+
+	return ret;
+}
+
+static int __maybe_unused tegra_fuse_resume(struct device *dev)
+{
+	int ret = 0;
+
+	if (fuse->soc->clk_suspend_on)
+		pm_runtime_put(dev);
+	else
+		ret = pm_runtime_force_resume(dev);
+
+	return ret;
+}
+
 static const struct dev_pm_ops tegra_fuse_pm = {
 	SET_RUNTIME_PM_OPS(tegra_fuse_runtime_suspend, tegra_fuse_runtime_resume,
 			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(tegra_fuse_suspend, tegra_fuse_resume)
 };
 
 static struct platform_driver tegra_fuse_driver = {
diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c
index cd6a273707fe..8ec9fc5e5e4b 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra20.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra20.c
@@ -167,4 +167,5 @@ const struct tegra_fuse_soc tegra20_fuse_soc = {
 	.probe = tegra20_fuse_probe,
 	.info = &tegra20_fuse_info,
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = false,
 };
diff --git a/drivers/soc/tegra/fuse/fuse-tegra30.c b/drivers/soc/tegra/fuse/fuse-tegra30.c
index dd03565a39a4..b071d433d74f 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra30.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra30.c
@@ -112,6 +112,7 @@ const struct tegra_fuse_soc tegra30_fuse_soc = {
 	.speedo_init = tegra30_init_speedo_data,
 	.info = &tegra30_fuse_info,
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
 
@@ -127,6 +128,7 @@ const struct tegra_fuse_soc tegra114_fuse_soc = {
 	.speedo_init = tegra114_init_speedo_data,
 	.info = &tegra114_fuse_info,
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
 
@@ -208,6 +210,7 @@ const struct tegra_fuse_soc tegra124_fuse_soc = {
 	.lookups = tegra124_fuse_lookups,
 	.num_lookups = ARRAY_SIZE(tegra124_fuse_lookups),
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = true,
 };
 #endif
 
@@ -294,6 +297,7 @@ const struct tegra_fuse_soc tegra210_fuse_soc = {
 	.lookups = tegra210_fuse_lookups,
 	.num_lookups = ARRAY_SIZE(tegra210_fuse_lookups),
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
 
@@ -324,6 +328,7 @@ const struct tegra_fuse_soc tegra186_fuse_soc = {
 	.lookups = tegra186_fuse_lookups,
 	.num_lookups = ARRAY_SIZE(tegra186_fuse_lookups),
 	.soc_attr_group = &tegra_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
 
@@ -354,6 +359,7 @@ const struct tegra_fuse_soc tegra194_fuse_soc = {
 	.lookups = tegra194_fuse_lookups,
 	.num_lookups = ARRAY_SIZE(tegra194_fuse_lookups),
 	.soc_attr_group = &tegra194_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
 
@@ -384,5 +390,6 @@ const struct tegra_fuse_soc tegra234_fuse_soc = {
 	.lookups = tegra234_fuse_lookups,
 	.num_lookups = ARRAY_SIZE(tegra234_fuse_lookups),
 	.soc_attr_group = &tegra194_soc_attr_group,
+	.clk_suspend_on = false,
 };
 #endif
diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h
index e057a58e2060..de58feba0435 100644
--- a/drivers/soc/tegra/fuse/fuse.h
+++ b/drivers/soc/tegra/fuse/fuse.h
@@ -34,6 +34,8 @@ struct tegra_fuse_soc {
 	unsigned int num_lookups;
 
 	const struct attribute_group *soc_attr_group;
+
+	bool clk_suspend_on;
 };
 
 struct tegra_fuse {
-- 
2.32.0

[PATCH v1 4/4] clk: tegra: Remove CLK_IS_CRITICAL flag from fuse clock

[Dmitry Osipenko]

FUSE driver now takes care of keeping the clock enabled when necessary.
Remove the CLK_IS_CRITICAL flag from the clock.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra-periph.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra-periph.c b/drivers/clk/tegra/clk-tegra-periph.c
index 292d6269daf1..4dcf7f7cb8a0 100644
--- a/drivers/clk/tegra/clk-tegra-periph.c
+++ b/drivers/clk/tegra/clk-tegra-periph.c
@@ -777,11 +777,7 @@ static struct tegra_periph_init_data gate_clks[] = {
 	GATE("ahbdma", "hclk", 33, 0, tegra_clk_ahbdma, 0),
 	GATE("apbdma", "pclk", 34, 0, tegra_clk_apbdma, 0),
 	GATE("kbc", "clk_32k", 36, TEGRA_PERIPH_ON_APB | TEGRA_PERIPH_NO_RESET, tegra_clk_kbc, 0),
-	/*
-	 * Critical for RAM re-repair operation, which must occur on resume
-	 * from LP1 system suspend and as part of CCPLEX cluster switching.
-	 */
-	GATE("fuse", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse, CLK_IS_CRITICAL),
+	GATE("fuse", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse, 0),
 	GATE("fuse_burn", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse_burn, 0),
 	GATE("kfuse", "clk_m", 40, TEGRA_PERIPH_ON_APB, tegra_clk_kfuse, 0),
 	GATE("apbif", "clk_m", 107, TEGRA_PERIPH_ON_APB, tegra_clk_apbif, 0),
-- 
2.32.0

Re: [PATCH v1 4/4] clk: tegra: Remove CLK_IS_CRITICAL flag from fuse clock

[Thierry Reding]

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On Tue, Aug 03, 2021 at 01:13:36AM +0300, Dmitry Osipenko wrote:
> FUSE driver now takes care of keeping the clock enabled when necessary.
> Remove the CLK_IS_CRITICAL flag from the clock.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/clk/tegra/clk-tegra-periph.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)

Mike, Stephen,

I've picked this up into the Tegra tree because it has a runtime
dependency on the patches earlier in this series.

Thierry

> 
> diff --git a/drivers/clk/tegra/clk-tegra-periph.c b/drivers/clk/tegra/clk-tegra-periph.c
> index 292d6269daf1..4dcf7f7cb8a0 100644
> --- a/drivers/clk/tegra/clk-tegra-periph.c
> +++ b/drivers/clk/tegra/clk-tegra-periph.c
> @@ -777,11 +777,7 @@ static struct tegra_periph_init_data gate_clks[] = {
>  	GATE("ahbdma", "hclk", 33, 0, tegra_clk_ahbdma, 0),
>  	GATE("apbdma", "pclk", 34, 0, tegra_clk_apbdma, 0),
>  	GATE("kbc", "clk_32k", 36, TEGRA_PERIPH_ON_APB | TEGRA_PERIPH_NO_RESET, tegra_clk_kbc, 0),
> -	/*
> -	 * Critical for RAM re-repair operation, which must occur on resume
> -	 * from LP1 system suspend and as part of CCPLEX cluster switching.
> -	 */
> -	GATE("fuse", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse, CLK_IS_CRITICAL),
> +	GATE("fuse", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse, 0),
>  	GATE("fuse_burn", "clk_m", 39, TEGRA_PERIPH_ON_APB, tegra_clk_fuse_burn, 0),
>  	GATE("kfuse", "clk_m", 40, TEGRA_PERIPH_ON_APB, tegra_clk_kfuse, 0),
>  	GATE("apbif", "clk_m", 107, TEGRA_PERIPH_ON_APB, tegra_clk_apbif, 0),
> -- 
> 2.32.0
> 

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Re: [PATCH v1 0/4] Tegra FUSE clock improvements for 5.15

[Thierry Reding]

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On Tue, Aug 03, 2021 at 01:13:32AM +0300, Dmitry Osipenko wrote:
> Hello,
> 
> This series improves handling of the FUSE clock by keeping it enabled only
> when necessary.
> 
> Dmitry Osipenko (4):
>   soc/tegra: fuse: Clear fuse->clk on driver probe failure
>   soc/tegra: fuse: Add runtime PM support
>   soc/tegra: fuse: Enable fuse clock on suspend for Tegra124
>   clk: tegra: Remove CLK_IS_CRITICAL flag from fuse clock
> 
>  drivers/clk/tegra/clk-tegra-periph.c  |  6 +--
>  drivers/soc/tegra/fuse/fuse-tegra.c   | 60 +++++++++++++++++++++++++++
>  drivers/soc/tegra/fuse/fuse-tegra20.c | 11 +++--
>  drivers/soc/tegra/fuse/fuse-tegra30.c | 16 ++++---
>  drivers/soc/tegra/fuse/fuse.h         |  2 +
>  5 files changed, 81 insertions(+), 14 deletions(-)

Applied, thanks.

Thierry

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