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

Paul Bolle
2015-03-02T08:49:52Z

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