Hi Jie,
This is a good patch, thanks!
Some comments below:
2009/12/14 Li Jie <eltshanli@xxxxxxxxx>:
> Hi, Wan ZongShun:
>
> This patch add cpufreq support for nuc900 CPUs.
>
> Signed-off-by: lijie <eltshanli@xxxxxxxxx>
> ---
> arch/arm/Kconfig | 1 +
> arch/arm/mach-w90x900/Makefile | 2 +-
> arch/arm/mach-w90x900/cpu.c | 4 +-
> arch/arm/mach-w90x900/cpufreq.c | 146 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 151 insertions(+), 2 deletions(-)
> create mode 100644 arch/arm/mach-w90x900/cpufreq.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index cf8a99f..60186fe 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -539,6 +539,7 @@ config ARCH_W90X900
> select COMMON_CLKDEV
> select GENERIC_TIME
> select GENERIC_CLOCKEVENTS
> + select ARCH_HAS_CPUFREQ
> help
> Support for Nuvoton (Winbond logic dept.) ARM9 processor,
> At present, the w90x900 has been renamed nuc900, regarding
> diff --git a/arch/arm/mach-w90x900/Makefile b/arch/arm/mach-w90x900/Makefile
> index 828c032..7f114fb 100644
> --- a/arch/arm/mach-w90x900/Makefile
> +++ b/arch/arm/mach-w90x900/Makefile
> @@ -5,7 +5,7 @@
> # Object file lists.
>
> obj-y := irq.o time.o mfp.o gpio.o clock.o
> -obj-y += clksel.o dev.o cpu.o
> +obj-y += clksel.o dev.o cpu.o cpufreq.o
> # W90X900 CPU support files
>
> obj-$(CONFIG_CPU_W90P910) += nuc910.o
> diff --git a/arch/arm/mach-w90x900/cpu.c b/arch/arm/mach-w90x900/cpu.c
> index 921cef9..7b608b8 100644
> --- a/arch/arm/mach-w90x900/cpu.c
> +++ b/arch/arm/mach-w90x900/cpu.c
> @@ -107,7 +107,7 @@ struct platform_device nuc900_serial_device = {
> };
>
> /*Set NUC900 series cpu frequence*/
> -static int __init nuc900_set_clkval(unsigned int cpufreq)
> +int nuc900_set_clkval(unsigned int cpufreq)
> {
> unsigned int pllclk, ahbclk, apbclk, val;
>
> @@ -156,6 +156,8 @@ static int __init nuc900_set_clkval(unsigned int cpufreq)
>
> return 0;
> }
> +EXPORT_SYMBOL(nuc900_set_clkval);
> +
> static int __init nuc900_set_cpufreq(char *str)
> {
> unsigned long cpufreq, val;
> diff --git a/arch/arm/mach-w90x900/cpufreq.c b/arch/arm/mach-w90x900/cpufreq.c
> new file mode 100644
> index 0000000..07b8685
> --- /dev/null
> +++ b/arch/arm/mach-w90x900/cpufreq.c
> @@ -0,0 +1,146 @@
> +/* linux/arch/arm/mach-w90x900/cpufreq.c
> + *
> + * NUC900 CPUfreq Support
> + *
> + * Li Jie <eltshanli@xxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/types.h>
> +#include <linux/init.h>
> +#include <linux/cpufreq.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +
> +#include <asm/io.h>
> +#include <mach/hardware.h>
> +#include <mach/regs-clock.h>
> +
> +extern int nuc900_set_clkval(unsigned int cpufreq);
> +
Please put this extern definition in cpu.h file and add include "cpu.h".
> +static struct cpufreq_frequency_table nuc900_freq_table[] = {
> + { 0, 66000 },
> + { 1, 100000 },
> + { 2, 120000 },
> + { 3, 166000 },
> + { 4, 200000 },
> + { 5, CPUFREQ_TABLE_END },
> +};
> +
Please define those cpu frequncy number as clear Marco, such as:
#define FREQ_66M 66000
and, the Macro can be re-used by below codes.
> +static int nuc900_cpufreq_verify_speed(struct cpufreq_policy *policy)
> +{
> + if (policy->cpu != 0)
> + return -EINVAL;
> +
> + return cpufreq_frequency_table_verify(policy, nuc900_freq_table);
> +}
> +
> +static unsigned int nuc900_cpufreq_get_speed(unsigned int cpu)
> +{
> + int pllclk;
> +
> + if (cpu != 0)
> + return 0;
> +
> + pllclk = __raw_readl(REG_PLLCON0);
> +
> + switch (pllclk) {
> + case PLL_66MHZ:
> + return 66 * 1000;
> + case PLL_100MHZ:
> + return 100 * 1000;
> + case PLL_120MHZ:
> + return 120 * 1000;
> + case PLL_166MHZ:
> + return 166 * 1000;
> + case PLL_200MHZ:
> + return 200 * 1000;
> + }
> +
> + pr_err("cpufreq: Failed to get frequency: %X\n", pllclk);
Though %X is right, but ,is lowercase more unanimous?
> + return 0;
> +}
> +
> +static int nuc900_cpufreq_set_target(struct cpufreq_policy *policy,
> + unsigned int target_freq,
> + unsigned int relation)
> +{
> + int ret;
> + unsigned int i;
> + struct cpufreq_freqs freqs;
> +
> + ret = cpufreq_frequency_table_target(policy, nuc900_freq_table,
> + target_freq, relation, &i);
> + if (ret != 0)
> + return ret;
> +
> + freqs.cpu = 0;
> + freqs.old = nuc900_cpufreq_get_speed(0);
> + freqs.new = nuc900_freq_table[i].frequency;
> + freqs.flags = 0;
> +
> + if (freqs.old == freqs.new)
> + return 0;
> +
> + pr_debug("cpufreq: Transition %d-%dkHz\n", freqs.old, freqs.new);
> +
> + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> +
> + nuc900_set_clkval(freqs.new / 1000);
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> +
> + return 0;
> +}
> +
> +static int __init nuc900_cpufreq_driver_init(struct cpufreq_policy *policy)
> +{
> + int ret;
> +
> + if (policy->cpu != 0)
> + return -EINVAL;
> +
> + policy->cur = nuc900_cpufreq_get_speed(0);
> +
> + policy->cpuinfo.transition_latency = 2 * 1000; /* FIXME, assumed */
> + policy->cpuinfo.min_freq = 66000; /* khz */
> + policy->cpuinfo.max_freq = 200000;
> + policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
> +
> + ret = cpufreq_frequency_table_cpuinfo(policy, nuc900_freq_table);
> + if (ret != 0)
> + pr_err("cpufreq: Failed to configure frequency table: %d\n",
> + ret);
> +
> + return ret;
> +}
> +
> +static struct cpufreq_driver nuc900_cpufreq_driver = {
> + .owner = THIS_MODULE,
> + .flags = 0,
> + .verify = nuc900_cpufreq_verify_speed,
> + .target = nuc900_cpufreq_set_target,
> + .get = nuc900_cpufreq_get_speed,
> + .init = nuc900_cpufreq_driver_init,
> + .name = "nuc900",
> +};
Don't name this cpufreq driver 'nuc900'.
> +static int __init nuc900_cpufreq_init(void)
> +{
> + return cpufreq_register_driver(&nuc900_cpufreq_driver);
> +}
> +
> +static void __exit nuc900_cpufreq_exit(void)
> +{
> + cpufreq_unregister_driver(&nuc900_cpufreq_driver);
> +}
> +
> +MODULE_AUTHOR ("Li Jie <eltshanli@xxxxxxxxx>");
> +MODULE_DESCRIPTION ("cpufreq driver for NUC900");
> +MODULE_LICENSE ("GPL");
> +
> +module_init(nuc900_cpufreq_init);
> +module_exit(nuc900_cpufreq_exit);
> --
> 1.6.5.4
>
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