diff mbox

[v1,10/11] cpufreq: tegra20: Wrap cpufreq into platform driver

Message ID 20180517180056.13336-11-digetx@gmail.com
State Changes Requested, archived
Headers show

Commit Message

Dmitry Osipenko May 17, 2018, 6 p.m. UTC
Currently tegra20-cpufreq kernel module isn't getting autoloaded because
there is no device associated with the module, this is one of two patches
that resolves the module autoloading. This patch adds a module alias that
will associate the tegra20-cpufreq kernel module with the platform device,
other patch will instantiate the actual platform device. And now it makes
sense to wrap cpufreq driver into a platform driver for consistency.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/cpufreq/tegra20-cpufreq.c | 116 +++++++++++++++++++-----------
 1 file changed, 73 insertions(+), 43 deletions(-)

Comments

Viresh Kumar May 18, 2018, 2:07 a.m. UTC | #1
On 17-05-18, 21:00, Dmitry Osipenko wrote:
> -static int __init tegra_cpufreq_init(void)
> +static int tegra20_cpufreq_probe(struct platform_device *pdev)
>  {
> +	struct tegra20_cpufreq_data *data;
>  	int err;
>  
> -	if (!of_machine_is_compatible("nvidia,tegra20"))
> -		return -ENODEV;

So this stuff wasn't really required as you are getting rid of that in
the same series. Should we really add it then ? Maybe ..

> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
>  
> -	cpu_clk = clk_get_sys(NULL, "cclk");
> -	if (IS_ERR(cpu_clk))
> -		return PTR_ERR(cpu_clk);
> +	data->cpu_clk = clk_get_sys(NULL, "cclk");
> +	if (IS_ERR(data->cpu_clk))
> +		return PTR_ERR(data->cpu_clk);
>  
> -	pll_x_clk = clk_get_sys(NULL, "pll_x");
> -	if (IS_ERR(pll_x_clk)) {
> -		err = PTR_ERR(pll_x_clk);
> +	data->pll_x_clk = clk_get_sys(NULL, "pll_x");
> +	if (IS_ERR(data->pll_x_clk)) {
> +		err = PTR_ERR(data->pll_x_clk);
>  		goto put_cpu;
>  	}
>  
> -	pll_p_clk = clk_get_sys(NULL, "pll_p");
> -	if (IS_ERR(pll_p_clk)) {
> -		err = PTR_ERR(pll_p_clk);
> +	data->pll_p_clk = clk_get_sys(NULL, "pll_p");
> +	if (IS_ERR(data->pll_p_clk)) {
> +		err = PTR_ERR(data->pll_p_clk);
>  		goto put_pll_x;
>  	}
>  
> +	data->dev = &pdev->dev;
> +
> +	tegra_cpufreq_driver.driver_data = data;
> +
>  	err = cpufreq_register_driver(&tegra_cpufreq_driver);
>  	if (err)
>  		goto put_pll_p;
>  
> +	platform_set_drvdata(pdev, data);
> +
>  	return 0;
>  
>  put_pll_p:
> -	clk_put(pll_p_clk);
> +	clk_put(data->pll_p_clk);
>  put_pll_x:
> -	clk_put(pll_x_clk);
> +	clk_put(data->pll_x_clk);
>  put_cpu:
> -	clk_put(cpu_clk);
> +	clk_put(data->cpu_clk);
>  
>  	return err;
>  }
>  
> -static void __exit tegra_cpufreq_exit(void)
> +static int tegra20_cpufreq_remove(struct platform_device *pdev)
>  {
> +	struct tegra20_cpufreq_data *data = platform_get_drvdata(pdev);
> +
>  	cpufreq_unregister_driver(&tegra_cpufreq_driver);
> -	clk_put(pll_p_clk);
> -	clk_put(pll_x_clk);
> -	clk_put(cpu_clk);
> +
> +	clk_put(data->pll_p_clk);
> +	clk_put(data->pll_x_clk);
> +	clk_put(data->cpu_clk);
> +
> +	return 0;
>  }
>  
> +static struct platform_driver tegra20_cpufreq_driver = {
> +	.probe		= tegra20_cpufreq_probe,
> +	.remove		= tegra20_cpufreq_remove,
> +	.driver		= {
> +		.name	= "tegra20-cpufreq",
> +	},
> +};
> +module_platform_driver(tegra20_cpufreq_driver);
> +
>  MODULE_AUTHOR("Colin Cross <ccross@android.com>");
> +MODULE_ALIAS("platform:tegra20-cpufreq");
>  MODULE_DESCRIPTION("NVIDIA Tegra20 cpufreq driver");
>  MODULE_LICENSE("GPL");
> -module_init(tegra_cpufreq_init);
> -module_exit(tegra_cpufreq_exit);

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Dmitry Osipenko May 18, 2018, 8:09 a.m. UTC | #2
On 18.05.2018 05:07, Viresh Kumar wrote:
> On 17-05-18, 21:00, Dmitry Osipenko wrote:
>> -static int __init tegra_cpufreq_init(void)
>> +static int tegra20_cpufreq_probe(struct platform_device *pdev)
>>  {
>> +	struct tegra20_cpufreq_data *data;
>>  	int err;
>>  
>> -	if (!of_machine_is_compatible("nvidia,tegra20"))
>> -		return -ENODEV;
> 
> So this stuff wasn't really required as you are getting rid of that in
> the same series. Should we really add it then ? Maybe ..
> 

It's not strictly needed, but I'd prefer to keep that stuff for clarity as it
kinda shows the way that led to the final result.

[snip]
Viresh Kumar May 18, 2018, 9:04 a.m. UTC | #3
On 18-05-18, 11:09, Dmitry Osipenko wrote:
> On 18.05.2018 05:07, Viresh Kumar wrote:
> > On 17-05-18, 21:00, Dmitry Osipenko wrote:
> >> -static int __init tegra_cpufreq_init(void)
> >> +static int tegra20_cpufreq_probe(struct platform_device *pdev)
> >>  {
> >> +	struct tegra20_cpufreq_data *data;
> >>  	int err;
> >>  
> >> -	if (!of_machine_is_compatible("nvidia,tegra20"))
> >> -		return -ENODEV;
> > 
> > So this stuff wasn't really required as you are getting rid of that in
> > the same series. Should we really add it then ? Maybe ..
> > 
> 
> It's not strictly needed, but I'd prefer to keep that stuff for clarity as it
> kinda shows the way that led to the final result.

Okay.
Thierry Reding May 18, 2018, 9:07 a.m. UTC | #4
On Thu, May 17, 2018 at 09:00:55PM +0300, Dmitry Osipenko wrote:
> Currently tegra20-cpufreq kernel module isn't getting autoloaded because
> there is no device associated with the module, this is one of two patches
> that resolves the module autoloading. This patch adds a module alias that
> will associate the tegra20-cpufreq kernel module with the platform device,
> other patch will instantiate the actual platform device. And now it makes
> sense to wrap cpufreq driver into a platform driver for consistency.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/cpufreq/tegra20-cpufreq.c | 116 +++++++++++++++++++-----------
>  1 file changed, 73 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
> index c0a7b5a78aa6..f9d02a28df9e 100644
> --- a/drivers/cpufreq/tegra20-cpufreq.c
> +++ b/drivers/cpufreq/tegra20-cpufreq.c
> @@ -19,7 +19,7 @@
>  #include <linux/clk.h>
>  #include <linux/cpufreq.h>
>  #include <linux/module.h>
> -#include <linux/of.h>
> +#include <linux/platform_device.h>
>  
>  static struct cpufreq_frequency_table freq_table[] = {
>  	{ .frequency = 216000 },
> @@ -33,15 +33,19 @@ static struct cpufreq_frequency_table freq_table[] = {
>  	{ .frequency = CPUFREQ_TABLE_END },
>  };
>  
> -static struct clk *cpu_clk;
> -static struct clk *pll_x_clk;
> -static struct clk *pll_p_clk;
> -static bool pll_x_prepared;
> +struct tegra20_cpufreq_data {

Nit: I'm not a big fan of _data suffixes because they are completely
redundant. Any data structure by definition hosts data, so I'd just drop
that.

[...]
> @@ -152,55 +161,76 @@ static struct cpufreq_driver tegra_cpufreq_driver = {
>  	.suspend		= cpufreq_generic_suspend,
>  };
>  
> -static int __init tegra_cpufreq_init(void)
> +static int tegra20_cpufreq_probe(struct platform_device *pdev)
>  {
> +	struct tegra20_cpufreq_data *data;
>  	int err;
>  
> -	if (!of_machine_is_compatible("nvidia,tegra20"))
> -		return -ENODEV;
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
>  
> -	cpu_clk = clk_get_sys(NULL, "cclk");
> -	if (IS_ERR(cpu_clk))
> -		return PTR_ERR(cpu_clk);
> +	data->cpu_clk = clk_get_sys(NULL, "cclk");
> +	if (IS_ERR(data->cpu_clk))
> +		return PTR_ERR(data->cpu_clk);
>  
> -	pll_x_clk = clk_get_sys(NULL, "pll_x");
> -	if (IS_ERR(pll_x_clk)) {
> -		err = PTR_ERR(pll_x_clk);
> +	data->pll_x_clk = clk_get_sys(NULL, "pll_x");
> +	if (IS_ERR(data->pll_x_clk)) {
> +		err = PTR_ERR(data->pll_x_clk);
>  		goto put_cpu;
>  	}
>  
> -	pll_p_clk = clk_get_sys(NULL, "pll_p");
> -	if (IS_ERR(pll_p_clk)) {
> -		err = PTR_ERR(pll_p_clk);
> +	data->pll_p_clk = clk_get_sys(NULL, "pll_p");
> +	if (IS_ERR(data->pll_p_clk)) {
> +		err = PTR_ERR(data->pll_p_clk);
>  		goto put_pll_x;
>  	}
>  
> +	data->dev = &pdev->dev;
> +
> +	tegra_cpufreq_driver.driver_data = data;

Couldn't this be embedded into struct tegra20_cpufreq_data? Moving
everything but this into a per-device data structure seems half-baked.

Thierry
Dmitry Osipenko May 18, 2018, 9:19 a.m. UTC | #5
On 18.05.2018 12:07, Thierry Reding wrote:
> On Thu, May 17, 2018 at 09:00:55PM +0300, Dmitry Osipenko wrote:
>> Currently tegra20-cpufreq kernel module isn't getting autoloaded because
>> there is no device associated with the module, this is one of two patches
>> that resolves the module autoloading. This patch adds a module alias that
>> will associate the tegra20-cpufreq kernel module with the platform device,
>> other patch will instantiate the actual platform device. And now it makes
>> sense to wrap cpufreq driver into a platform driver for consistency.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  drivers/cpufreq/tegra20-cpufreq.c | 116 +++++++++++++++++++-----------
>>  1 file changed, 73 insertions(+), 43 deletions(-)
>>
>> diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
>> index c0a7b5a78aa6..f9d02a28df9e 100644
>> --- a/drivers/cpufreq/tegra20-cpufreq.c
>> +++ b/drivers/cpufreq/tegra20-cpufreq.c
>> @@ -19,7 +19,7 @@
>>  #include <linux/clk.h>
>>  #include <linux/cpufreq.h>
>>  #include <linux/module.h>
>> -#include <linux/of.h>
>> +#include <linux/platform_device.h>
>>  
>>  static struct cpufreq_frequency_table freq_table[] = {
>>  	{ .frequency = 216000 },
>> @@ -33,15 +33,19 @@ static struct cpufreq_frequency_table freq_table[] = {
>>  	{ .frequency = CPUFREQ_TABLE_END },
>>  };
>>  
>> -static struct clk *cpu_clk;
>> -static struct clk *pll_x_clk;
>> -static struct clk *pll_p_clk;
>> -static bool pll_x_prepared;
>> +struct tegra20_cpufreq_data {
> 
> Nit: I'm not a big fan of _data suffixes because they are completely
> redundant. Any data structure by definition hosts data, so I'd just drop
> that.

Okay, I'll drop it in v2.

> [...]
>> @@ -152,55 +161,76 @@ static struct cpufreq_driver tegra_cpufreq_driver = {
>>  	.suspend		= cpufreq_generic_suspend,
>>  };
>>  
>> -static int __init tegra_cpufreq_init(void)
>> +static int tegra20_cpufreq_probe(struct platform_device *pdev)
>>  {
>> +	struct tegra20_cpufreq_data *data;
>>  	int err;
>>  
>> -	if (!of_machine_is_compatible("nvidia,tegra20"))
>> -		return -ENODEV;
>> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>>  
>> -	cpu_clk = clk_get_sys(NULL, "cclk");
>> -	if (IS_ERR(cpu_clk))
>> -		return PTR_ERR(cpu_clk);
>> +	data->cpu_clk = clk_get_sys(NULL, "cclk");
>> +	if (IS_ERR(data->cpu_clk))
>> +		return PTR_ERR(data->cpu_clk);
>>  
>> -	pll_x_clk = clk_get_sys(NULL, "pll_x");
>> -	if (IS_ERR(pll_x_clk)) {
>> -		err = PTR_ERR(pll_x_clk);
>> +	data->pll_x_clk = clk_get_sys(NULL, "pll_x");
>> +	if (IS_ERR(data->pll_x_clk)) {
>> +		err = PTR_ERR(data->pll_x_clk);
>>  		goto put_cpu;
>>  	}
>>  
>> -	pll_p_clk = clk_get_sys(NULL, "pll_p");
>> -	if (IS_ERR(pll_p_clk)) {
>> -		err = PTR_ERR(pll_p_clk);
>> +	data->pll_p_clk = clk_get_sys(NULL, "pll_p");
>> +	if (IS_ERR(data->pll_p_clk)) {
>> +		err = PTR_ERR(data->pll_p_clk);
>>  		goto put_pll_x;
>>  	}
>>  
>> +	data->dev = &pdev->dev;
>> +
>> +	tegra_cpufreq_driver.driver_data = data;
> 
> Couldn't this be embedded into struct tegra20_cpufreq_data? Moving
> everything but this into a per-device data structure seems half-baked.

That's a good suggestions, thank you.
diff mbox

Patch

diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
index c0a7b5a78aa6..f9d02a28df9e 100644
--- a/drivers/cpufreq/tegra20-cpufreq.c
+++ b/drivers/cpufreq/tegra20-cpufreq.c
@@ -19,7 +19,7 @@ 
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/platform_device.h>
 
 static struct cpufreq_frequency_table freq_table[] = {
 	{ .frequency = 216000 },
@@ -33,15 +33,19 @@  static struct cpufreq_frequency_table freq_table[] = {
 	{ .frequency = CPUFREQ_TABLE_END },
 };
 
-static struct clk *cpu_clk;
-static struct clk *pll_x_clk;
-static struct clk *pll_p_clk;
-static bool pll_x_prepared;
+struct tegra20_cpufreq_data {
+	struct device *dev;
+	struct clk *cpu_clk;
+	struct clk *pll_x_clk;
+	struct clk *pll_p_clk;
+	bool pll_x_prepared;
+};
 
 static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
 					   unsigned int index)
 {
-	unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
+	struct tegra20_cpufreq_data *data = cpufreq_get_driver_data();
+	unsigned int ifreq = clk_get_rate(data->pll_p_clk) / 1000;
 
 	/*
 	 * Don't switch to intermediate freq if:
@@ -57,6 +61,7 @@  static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
 static int tegra_target_intermediate(struct cpufreq_policy *policy,
 				     unsigned int index)
 {
+	struct tegra20_cpufreq_data *data = cpufreq_get_driver_data();
 	int ret;
 
 	/*
@@ -69,21 +74,22 @@  static int tegra_target_intermediate(struct cpufreq_policy *policy,
 	 * Also, we wouldn't be using pll_x anymore and must not take extra
 	 * reference to it, as it can be disabled now to save some power.
 	 */
-	clk_prepare_enable(pll_x_clk);
+	clk_prepare_enable(data->pll_x_clk);
 
-	ret = clk_set_parent(cpu_clk, pll_p_clk);
+	ret = clk_set_parent(data->cpu_clk, data->pll_p_clk);
 	if (ret)
-		clk_disable_unprepare(pll_x_clk);
+		clk_disable_unprepare(data->pll_x_clk);
 	else
-		pll_x_prepared = true;
+		data->pll_x_prepared = true;
 
 	return ret;
 }
 
 static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 {
+	struct tegra20_cpufreq_data *data = cpufreq_get_driver_data();
 	unsigned long rate = freq_table[index].frequency;
-	unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
+	unsigned int ifreq = clk_get_rate(data->pll_p_clk) / 1000;
 	int ret;
 
 	/*
@@ -91,14 +97,14 @@  static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 	 * as it isn't used anymore.
 	 */
 	if (rate == ifreq)
-		return clk_set_parent(cpu_clk, pll_p_clk);
+		return clk_set_parent(data->cpu_clk, data->pll_p_clk);
 
-	ret = clk_set_rate(pll_x_clk, rate * 1000);
+	ret = clk_set_rate(data->pll_x_clk, rate * 1000);
 	/* Restore to earlier frequency on error, i.e. pll_x */
 	if (ret)
-		pr_err("Failed to change pll_x to %lu\n", rate);
+		dev_err(data->dev, "Failed to change pll_x to %lu\n", rate);
 
-	ret = clk_set_parent(cpu_clk, pll_x_clk);
+	ret = clk_set_parent(data->cpu_clk, data->pll_x_clk);
 	/* This shouldn't fail while changing or restoring */
 	WARN_ON(ret);
 
@@ -106,9 +112,9 @@  static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 	 * Drop count to pll_x clock only if we switched to intermediate freq
 	 * earlier while transitioning to a target frequency.
 	 */
-	if (pll_x_prepared) {
-		clk_disable_unprepare(pll_x_clk);
-		pll_x_prepared = false;
+	if (data->pll_x_prepared) {
+		clk_disable_unprepare(data->pll_x_clk);
+		data->pll_x_prepared = false;
 	}
 
 	return ret;
@@ -116,25 +122,28 @@  static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 
 static int tegra_cpu_init(struct cpufreq_policy *policy)
 {
+	struct tegra20_cpufreq_data *data = cpufreq_get_driver_data();
 	int ret;
 
-	clk_prepare_enable(cpu_clk);
+	clk_prepare_enable(data->cpu_clk);
 
 	/* FIXME: what's the actual transition time? */
 	ret = cpufreq_generic_init(policy, freq_table, 300 * 1000);
 	if (ret) {
-		clk_disable_unprepare(cpu_clk);
+		clk_disable_unprepare(data->cpu_clk);
 		return ret;
 	}
 
-	policy->clk = cpu_clk;
+	policy->clk = data->cpu_clk;
 	policy->suspend_freq = freq_table[0].frequency;
 	return 0;
 }
 
 static int tegra_cpu_exit(struct cpufreq_policy *policy)
 {
-	clk_disable_unprepare(cpu_clk);
+	struct tegra20_cpufreq_data *data = cpufreq_get_driver_data();
+
+	clk_disable_unprepare(data->cpu_clk);
 	return 0;
 }
 
@@ -152,55 +161,76 @@  static struct cpufreq_driver tegra_cpufreq_driver = {
 	.suspend		= cpufreq_generic_suspend,
 };
 
-static int __init tegra_cpufreq_init(void)
+static int tegra20_cpufreq_probe(struct platform_device *pdev)
 {
+	struct tegra20_cpufreq_data *data;
 	int err;
 
-	if (!of_machine_is_compatible("nvidia,tegra20"))
-		return -ENODEV;
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
 
-	cpu_clk = clk_get_sys(NULL, "cclk");
-	if (IS_ERR(cpu_clk))
-		return PTR_ERR(cpu_clk);
+	data->cpu_clk = clk_get_sys(NULL, "cclk");
+	if (IS_ERR(data->cpu_clk))
+		return PTR_ERR(data->cpu_clk);
 
-	pll_x_clk = clk_get_sys(NULL, "pll_x");
-	if (IS_ERR(pll_x_clk)) {
-		err = PTR_ERR(pll_x_clk);
+	data->pll_x_clk = clk_get_sys(NULL, "pll_x");
+	if (IS_ERR(data->pll_x_clk)) {
+		err = PTR_ERR(data->pll_x_clk);
 		goto put_cpu;
 	}
 
-	pll_p_clk = clk_get_sys(NULL, "pll_p");
-	if (IS_ERR(pll_p_clk)) {
-		err = PTR_ERR(pll_p_clk);
+	data->pll_p_clk = clk_get_sys(NULL, "pll_p");
+	if (IS_ERR(data->pll_p_clk)) {
+		err = PTR_ERR(data->pll_p_clk);
 		goto put_pll_x;
 	}
 
+	data->dev = &pdev->dev;
+
+	tegra_cpufreq_driver.driver_data = data;
+
 	err = cpufreq_register_driver(&tegra_cpufreq_driver);
 	if (err)
 		goto put_pll_p;
 
+	platform_set_drvdata(pdev, data);
+
 	return 0;
 
 put_pll_p:
-	clk_put(pll_p_clk);
+	clk_put(data->pll_p_clk);
 put_pll_x:
-	clk_put(pll_x_clk);
+	clk_put(data->pll_x_clk);
 put_cpu:
-	clk_put(cpu_clk);
+	clk_put(data->cpu_clk);
 
 	return err;
 }
 
-static void __exit tegra_cpufreq_exit(void)
+static int tegra20_cpufreq_remove(struct platform_device *pdev)
 {
+	struct tegra20_cpufreq_data *data = platform_get_drvdata(pdev);
+
 	cpufreq_unregister_driver(&tegra_cpufreq_driver);
-	clk_put(pll_p_clk);
-	clk_put(pll_x_clk);
-	clk_put(cpu_clk);
+
+	clk_put(data->pll_p_clk);
+	clk_put(data->pll_x_clk);
+	clk_put(data->cpu_clk);
+
+	return 0;
 }
 
+static struct platform_driver tegra20_cpufreq_driver = {
+	.probe		= tegra20_cpufreq_probe,
+	.remove		= tegra20_cpufreq_remove,
+	.driver		= {
+		.name	= "tegra20-cpufreq",
+	},
+};
+module_platform_driver(tegra20_cpufreq_driver);
+
 MODULE_AUTHOR("Colin Cross <ccross@android.com>");
+MODULE_ALIAS("platform:tegra20-cpufreq");
 MODULE_DESCRIPTION("NVIDIA Tegra20 cpufreq driver");
 MODULE_LICENSE("GPL");
-module_init(tegra_cpufreq_init);
-module_exit(tegra_cpufreq_exit);