[PATCH] ARM: NUC900: Add cpufreq driver for nuc900 CPUs
Li Jie
eltshanli at gmail.com
Sat Dec 19 05:01:52 EST 2009
On Sat, Dec 19, 2009 at 1:34 AM, Wan ZongShun <mcuos.com at gmail.com> wrote:
> Hi Jie,
>
> This is a good patch, thanks!
> Some comments below:
Hi Wan,
Thanks for you comments,
I'll send a new patch later.
>
> 2009/12/14 Li Jie <eltshanli at gmail.com>:
>> Hi, Wan ZongShun:
>>
>> This patch add cpufreq support for nuc900 CPUs.
>>
>> Signed-off-by: lijie <eltshanli at gmail.com>
>> ---
>> 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 at gmail.com>
>> + *
>> + * 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 at gmail.com>");
>> +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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--
Regards
Li Jie
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