On 12/12/2013 02:33 AM, Bill Huang wrote:
> Re-model Tegra20 cpufreq driver as below.
>
> * Rename tegra-cpufreq.c to tegra20-cpufreq.c since this file supports
> only Tegra20.
> * Add probe function so defer probe can be used when we're going to
> support DVFS.
> * Create a fake cpufreq platform device with its name being
> "${root_compatible}-cpufreq" so SoC cpufreq driver can bind to it
> accordingly.
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> +config ARM_TEGRA20_CPUFREQ
> + bool "NVIDIA TEGRA20"
> + depends on ARM_TEGRA_CPUFREQ && ARCH_TEGRA_2x_SOC
> + default y
> + help
> + This enables Tegra20 cpufreq functionality, it adds
> + Tegra20 CPU frequency ladder and the call back functions
> + to set CPU rate. All the non-SoC dependant codes are
> + controlled by the config ARM_TEGRA20_CPUFREQ.
I think that last sentence is no longer true in this patch version. Or,
did you mean to write ARM_TEGRA_CPUFREQ rather than ARM_TEGRA20_CPUFREQ?
> diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c
> +static const char * const tegra_soc_compat[] = {
> + "nvidia,tegra124",
> + "nvidia,tegra114",
> + "nvidia,tegra30",
> + "nvidia,tegra20",
> + NULL
> };
That table will need editing for each chip. I wonder if you can do
something like always use the very last entry in /compatible. That would
assume a particular ordering of the compatible entries, but they should
be in the order $board, $soc anyway...
> +int __init tegra_cpufreq_init(void)
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(tegra_soc_compat); i++) {
> + if (of_machine_is_compatible(tegra_soc_compat[i])) {
> + struct platform_device_info devinfo;
> + char buf[40];
> +
> + memset(&devinfo, 0, sizeof(devinfo));
> + strcpy(buf, tegra_soc_compat[i]);
> + strcat(buf, "-cpufreq");
kasprintf() might be simpler, and would avoid the arbitrary 39-character
string limit and possibility of overflow.
> + devinfo.name = buf;
> + platform_device_register_full(&devinfo);
Does the devinfo struct need to stick around, i.e. does
platform_device_register_full keep the pointer, or take a copy of the
struct? If it keeps the pointer, it'd be best to make devinfo a static
global variable.
> diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
Please pass the "-C" option to "git format-patch"; I assume that almost
all the code in this file is simply cut/paste verbatim from
tegra-cpufreq.c where it was deleted.
> + * Copyright (C) 2010 Google, Inc.
It's worth adding NV (c) here too.
> +static int tegra20_cpufreq_remove(struct platform_device *pdev)
> +{
> + cpufreq_unregister_driver(&tegra20_cpufreq_driver);
> + return 0;
> +}
That leaks all the clk_get_sys() calls. Does building this as a module
work OK?
> +MODULE_LICENSE("GPL");
That should be "GPL v2".
> diff --git a/include/linux/tegra-cpufreq.h b/include/linux/tegra-cpufreq.h
> +#ifdef CONFIG_ARM_TEGRA_CPUFREQ
> +int tegra_cpufreq_init(void);
> +#else
> +static inline int tegra_cpufreq_init(void)
> +{ return; }
> +#endif
If you're going to wrap the { } onto one line, then I think it'd be best
to wrap the whole thing (prototype and body) onto one line. Otherwise,
write:
{
return;
}
Oh, and you need "return 0" not just "return".
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