Re: [PATCH v8 15/18] cpufreq: Add cpufreq driver for Tegra124

[Mikko Perttunen <mikko.perttunen@kapsi.fi>]

On 03/02/2015 10:49 AM, Paul Bolle wrote:
> On Sun, 2015-03-01 at 14:44 +0200, Mikko Perttunen wrote:
>> --- a/drivers/cpufreq/Kconfig.arm
>> +++ b/drivers/cpufreq/Kconfig.arm
>> @@ -256,6 +256,13 @@ config ARM_TEGRA20_CPUFREQ
>>   	help
>>   	  This adds the CPUFreq driver support for Tegra20 SOCs.
>>
>> +config ARM_TEGRA124_CPUFREQ
>> +	bool "Tegra124 CPUFreq support"
>
> This adds a bool Kconfig symbol...
>
>> +	depends on ARCH_TEGRA && CPUFREQ_DT
>> +	default y
>> +	help
>> +	  This adds the CPUFreq driver support for Tegra124 SOCs.
>> +
>>   config ARM_PXA2xx_CPUFREQ
>>   	tristate "Intel PXA2xx CPUfreq driver"
>>   	depends on PXA27x || PXA25x
>> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
>> index 312d9c3..d478b83 100644
>> --- a/drivers/cpufreq/Makefile
>> +++ b/drivers/cpufreq/Makefile
>> @@ -77,6 +77,7 @@ obj-$(CONFIG_ARM_SA1100_CPUFREQ)	+= sa1100-cpufreq.o
>>   obj-$(CONFIG_ARM_SA1110_CPUFREQ)	+= sa1110-cpufreq.o
>>   obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
>>   obj-$(CONFIG_ARM_TEGRA20_CPUFREQ)	+= tegra20-cpufreq.o
>> +obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
>
> ... so this object will either not be built or be built-in.
>
>>   obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
>>
>>   ##################################################################################
>> diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
>> new file mode 100644
>> index 0000000..45778ce
>> --- /dev/null
>> +++ b/drivers/cpufreq/tegra124-cpufreq.c
>> @@ -0,0 +1,217 @@
>> +/*
>> + * Tegra 124 cpufreq driver
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/clk.h>
>> +#include <linux/cpufreq-dt.h>
>> +#include <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>
> Is linux/module.h needed?
>
>> +#include <linux/of_device.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_opp.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/types.h>
>
> [...]
>
>> +static struct platform_driver tegra124_cpufreq_platdrv = {
>> +	.driver = {
>> +		.name	= "cpufreq-tegra124",
>> +		.owner	= THIS_MODULE,
>
> .owner will always be, in short, NULL.
>
>> +	},
>> +	.probe		= tegra124_cpufreq_probe,
>> +	.remove		= tegra124_cpufreq_remove,
>> +};
>
> [...]
>
>> +module_init(tegra_cpufreq_init);
>
> This might as well be, I think, device_initcall().
>
>> +MODULE_AUTHOR("Tuomas Tynkkynen <ttynkkynen@nvidia.com>");
>> +MODULE_DESCRIPTION("cpufreq driver for NVIDIA Tegra124");
>> +MODULE_LICENSE("GPL v2");
>
> The strings in these macros will always be preprocessed away, because
> this driver cannot become a module.
>
>
> Paul Bolle
>

Well noticed! I changed the config symbol to be tristate.

Thanks,
Mikko Perttunen