diff mbox series

[v7,11/20] cpufreq: tegra124: Add suspend and resume support

Message ID 1564532424-10449-12-git-send-email-skomatineni@nvidia.com
State Superseded
Headers show
Series SC7 entry and exit support for Tegra210 | expand

Commit Message

Sowjanya Komatineni July 31, 2019, 12:20 a.m. UTC
This patch adds suspend and resume pm ops for cpufreq driver.

PLLP is the safe clock source for CPU during system suspend and
resume as PLLP rate is below the CPU Fmax at Vmin.

CPUFreq driver suspend switches the CPU clock source to PLLP and
disables the DFLL clock.

During system resume, warmboot code powers up the CPU with PLLP
clock source. So CPUFreq driver resume enabled DFLL clock and
switches CPU back to DFLL clock source.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/cpufreq/tegra124-cpufreq.c | 60 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

Comments

Dmitry Osipenko July 31, 2019, 10:23 a.m. UTC | #1
31.07.2019 3:20, Sowjanya Komatineni пишет:
> This patch adds suspend and resume pm ops for cpufreq driver.
> 
> PLLP is the safe clock source for CPU during system suspend and
> resume as PLLP rate is below the CPU Fmax at Vmin.
> 
> CPUFreq driver suspend switches the CPU clock source to PLLP and
> disables the DFLL clock.
> 
> During system resume, warmboot code powers up the CPU with PLLP
> clock source. So CPUFreq driver resume enabled DFLL clock and
> switches CPU back to DFLL clock source.
> 
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
>  drivers/cpufreq/tegra124-cpufreq.c | 60 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
> index 4f0c637b3b49..e979a3370988 100644
> --- a/drivers/cpufreq/tegra124-cpufreq.c
> +++ b/drivers/cpufreq/tegra124-cpufreq.c
> @@ -6,6 +6,7 @@
>  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>  
>  #include <linux/clk.h>
> +#include <linux/cpufreq.h>
>  #include <linux/err.h>
>  #include <linux/init.h>
>  #include <linux/kernel.h>
> @@ -128,8 +129,67 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev)
> +{
> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
> +	int err;
> +
> +	/*
> +	 * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to
> +	 * use during suspend and resume. So, switch the CPU clock source
> +	 * to PLLP and disable DFLL.
> +	 */
> +	err = clk_set_parent(priv->cpu_clk, priv->pllp_clk);
> +	if (err < 0) {
> +		dev_err(dev, "failed to reparent to PLLP: %d\n", err);
> +		return err;
> +	}
> +
> +	/* disable DFLL clock */
> +	clk_disable_unprepare(priv->dfll_clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
> +{
> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
> +	int err;
> +
> +	/*
> +	 * Warmboot code powers up the CPU with PLLP clock source.
> +	 * Enable DFLL clock and switch CPU clock source back to DFLL.
> +	 */
> +	err = clk_prepare_enable(priv->dfll_clk);
> +	if (err < 0) {
> +		dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err);
> +		goto disable_cpufreq;
> +	}
> +
> +	err = clk_set_parent(priv->cpu_clk, priv->dfll_clk);
> +	if (err < 0) {
> +		dev_err(dev, "failed to reparent to DFLL clock: %d\n", err);
> +		goto disable_dfll;
> +	}
> +
> +	return 0;
> +
> +disable_dfll:
> +	clk_disable_unprepare(priv->dfll_clk);
> +disable_cpufreq:
> +	disable_cpufreq();
> +
> +	return err;
> +}
> +
> +static const struct dev_pm_ops tegra124_cpufreq_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend,
> +				tegra124_cpufreq_resume)
> +};
> +
>  static struct platform_driver tegra124_cpufreq_platdrv = {
>  	.driver.name	= "cpufreq-tegra124",
> +	.driver.pm	= &tegra124_cpufreq_pm_ops,
>  	.probe		= tegra124_cpufreq_probe,
>  };
>  
> 

Looks good,

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Dmitry Osipenko July 31, 2019, 11:14 a.m. UTC | #2
31.07.2019 13:23, Dmitry Osipenko пишет:
> 31.07.2019 3:20, Sowjanya Komatineni пишет:
>> This patch adds suspend and resume pm ops for cpufreq driver.
>>
>> PLLP is the safe clock source for CPU during system suspend and
>> resume as PLLP rate is below the CPU Fmax at Vmin.
>>
>> CPUFreq driver suspend switches the CPU clock source to PLLP and
>> disables the DFLL clock.
>>
>> During system resume, warmboot code powers up the CPU with PLLP
>> clock source. So CPUFreq driver resume enabled DFLL clock and
>> switches CPU back to DFLL clock source.
>>
>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>> ---
>>  drivers/cpufreq/tegra124-cpufreq.c | 60 ++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 60 insertions(+)
>>
>> diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
>> index 4f0c637b3b49..e979a3370988 100644
>> --- a/drivers/cpufreq/tegra124-cpufreq.c
>> +++ b/drivers/cpufreq/tegra124-cpufreq.c
>> @@ -6,6 +6,7 @@
>>  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>>  
>>  #include <linux/clk.h>
>> +#include <linux/cpufreq.h>
>>  #include <linux/err.h>
>>  #include <linux/init.h>
>>  #include <linux/kernel.h>
>> @@ -128,8 +129,67 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>>  	return ret;
>>  }
>>  
>> +static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev)
>> +{
>> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
>> +	int err;
>> +
>> +	/*
>> +	 * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to
>> +	 * use during suspend and resume. So, switch the CPU clock source
>> +	 * to PLLP and disable DFLL.
>> +	 */
>> +	err = clk_set_parent(priv->cpu_clk, priv->pllp_clk);
>> +	if (err < 0) {
>> +		dev_err(dev, "failed to reparent to PLLP: %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	/* disable DFLL clock */
>> +	clk_disable_unprepare(priv->dfll_clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
>> +{
>> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
>> +	int err;
>> +
>> +	/*
>> +	 * Warmboot code powers up the CPU with PLLP clock source.
>> +	 * Enable DFLL clock and switch CPU clock source back to DFLL.
>> +	 */
>> +	err = clk_prepare_enable(priv->dfll_clk);
>> +	if (err < 0) {
>> +		dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err);
>> +		goto disable_cpufreq;
>> +	}
>> +
>> +	err = clk_set_parent(priv->cpu_clk, priv->dfll_clk);
>> +	if (err < 0) {
>> +		dev_err(dev, "failed to reparent to DFLL clock: %d\n", err);
>> +		goto disable_dfll;
>> +	}
>> +
>> +	return 0;
>> +
>> +disable_dfll:
>> +	clk_disable_unprepare(priv->dfll_clk);
>> +disable_cpufreq:
>> +	disable_cpufreq();
>> +
>> +	return err;
>> +}
>> +
>> +static const struct dev_pm_ops tegra124_cpufreq_pm_ops = {
>> +	SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend,
>> +				tegra124_cpufreq_resume)
>> +};
>> +
>>  static struct platform_driver tegra124_cpufreq_platdrv = {
>>  	.driver.name	= "cpufreq-tegra124",
>> +	.driver.pm	= &tegra124_cpufreq_pm_ops,
>>  	.probe		= tegra124_cpufreq_probe,
>>  };
>>  
>>
> 
> Looks good,
> 
> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
> 

BTW, you should also CC the CPUFreq maintainers because this patch can't
be applied without theirs ACK.
Sowjanya Komatineni July 31, 2019, 9:05 p.m. UTC | #3
On 7/31/19 4:14 AM, Dmitry Osipenko wrote:
> 31.07.2019 13:23, Dmitry Osipenko пишет:
>> 31.07.2019 3:20, Sowjanya Komatineni пишет:
>>> This patch adds suspend and resume pm ops for cpufreq driver.
>>>
>>> PLLP is the safe clock source for CPU during system suspend and
>>> resume as PLLP rate is below the CPU Fmax at Vmin.
>>>
>>> CPUFreq driver suspend switches the CPU clock source to PLLP and
>>> disables the DFLL clock.
>>>
>>> During system resume, warmboot code powers up the CPU with PLLP
>>> clock source. So CPUFreq driver resume enabled DFLL clock and
>>> switches CPU back to DFLL clock source.
>>>
>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>> ---
>>>   drivers/cpufreq/tegra124-cpufreq.c | 60 ++++++++++++++++++++++++++++++++++++++
>>>   1 file changed, 60 insertions(+)
>>>
>>> diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
>>> index 4f0c637b3b49..e979a3370988 100644
>>> --- a/drivers/cpufreq/tegra124-cpufreq.c
>>> +++ b/drivers/cpufreq/tegra124-cpufreq.c
>>> @@ -6,6 +6,7 @@
>>>   #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>>>   
>>>   #include <linux/clk.h>
>>> +#include <linux/cpufreq.h>
>>>   #include <linux/err.h>
>>>   #include <linux/init.h>
>>>   #include <linux/kernel.h>
>>> @@ -128,8 +129,67 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>>>   	return ret;
>>>   }
>>>   
>>> +static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev)
>>> +{
>>> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
>>> +	int err;
>>> +
>>> +	/*
>>> +	 * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to
>>> +	 * use during suspend and resume. So, switch the CPU clock source
>>> +	 * to PLLP and disable DFLL.
>>> +	 */
>>> +	err = clk_set_parent(priv->cpu_clk, priv->pllp_clk);
>>> +	if (err < 0) {
>>> +		dev_err(dev, "failed to reparent to PLLP: %d\n", err);
>>> +		return err;
>>> +	}
>>> +
>>> +	/* disable DFLL clock */
>>> +	clk_disable_unprepare(priv->dfll_clk);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
>>> +{
>>> +	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
>>> +	int err;
>>> +
>>> +	/*
>>> +	 * Warmboot code powers up the CPU with PLLP clock source.
>>> +	 * Enable DFLL clock and switch CPU clock source back to DFLL.
>>> +	 */
>>> +	err = clk_prepare_enable(priv->dfll_clk);
>>> +	if (err < 0) {
>>> +		dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err);
>>> +		goto disable_cpufreq;
>>> +	}
>>> +
>>> +	err = clk_set_parent(priv->cpu_clk, priv->dfll_clk);
>>> +	if (err < 0) {
>>> +		dev_err(dev, "failed to reparent to DFLL clock: %d\n", err);
>>> +		goto disable_dfll;
>>> +	}
>>> +
>>> +	return 0;
>>> +
>>> +disable_dfll:
>>> +	clk_disable_unprepare(priv->dfll_clk);
>>> +disable_cpufreq:
>>> +	disable_cpufreq();
>>> +
>>> +	return err;
>>> +}
>>> +
>>> +static const struct dev_pm_ops tegra124_cpufreq_pm_ops = {
>>> +	SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend,
>>> +				tegra124_cpufreq_resume)
>>> +};
>>> +
>>>   static struct platform_driver tegra124_cpufreq_platdrv = {
>>>   	.driver.name	= "cpufreq-tegra124",
>>> +	.driver.pm	= &tegra124_cpufreq_pm_ops,
>>>   	.probe		= tegra124_cpufreq_probe,
>>>   };
>>>   
>>>
>> Looks good,
>>
>> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
>>
> BTW, you should also CC the CPUFreq maintainers because this patch can't
> be applied without theirs ACK.
MIssed them. Will resend v7 series with CPUFreq maintainers...
diff mbox series

Patch

diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
index 4f0c637b3b49..e979a3370988 100644
--- a/drivers/cpufreq/tegra124-cpufreq.c
+++ b/drivers/cpufreq/tegra124-cpufreq.c
@@ -6,6 +6,7 @@ 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
+#include <linux/cpufreq.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -128,8 +129,67 @@  static int tegra124_cpufreq_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev)
+{
+	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
+	int err;
+
+	/*
+	 * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to
+	 * use during suspend and resume. So, switch the CPU clock source
+	 * to PLLP and disable DFLL.
+	 */
+	err = clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to reparent to PLLP: %d\n", err);
+		return err;
+	}
+
+	/* disable DFLL clock */
+	clk_disable_unprepare(priv->dfll_clk);
+
+	return 0;
+}
+
+static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
+{
+	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
+	int err;
+
+	/*
+	 * Warmboot code powers up the CPU with PLLP clock source.
+	 * Enable DFLL clock and switch CPU clock source back to DFLL.
+	 */
+	err = clk_prepare_enable(priv->dfll_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err);
+		goto disable_cpufreq;
+	}
+
+	err = clk_set_parent(priv->cpu_clk, priv->dfll_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to reparent to DFLL clock: %d\n", err);
+		goto disable_dfll;
+	}
+
+	return 0;
+
+disable_dfll:
+	clk_disable_unprepare(priv->dfll_clk);
+disable_cpufreq:
+	disable_cpufreq();
+
+	return err;
+}
+
+static const struct dev_pm_ops tegra124_cpufreq_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend,
+				tegra124_cpufreq_resume)
+};
+
 static struct platform_driver tegra124_cpufreq_platdrv = {
 	.driver.name	= "cpufreq-tegra124",
+	.driver.pm	= &tegra124_cpufreq_pm_ops,
 	.probe		= tegra124_cpufreq_probe,
 };