[PATCH V2 7/7] arm/imx6q: add cpufreq support

[Richard Zhao]

On Tue, Dec 13, 2011 at 11:23:15AM +0100, Sascha Hauer wrote:
> On Tue, Dec 13, 2011 at 02:25:30PM +0800, Richard Zhao wrote:
> > use cpu0 node property clock-frequency to check max frequency.
> > 
> > Signed-off-by: Richard Zhao <richard.zhao at linaro.org>
> > ---
> >  arch/arm/mach-imx/Kconfig        |    1 +
> >  arch/arm/mach-imx/Makefile       |    2 +-
> >  arch/arm/mach-imx/cpu_op-imx6q.c |   69 ++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 71 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/arm/mach-imx/cpu_op-imx6q.c
> > 
> > diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> > index fbd414b..21e472f 100644
> > --- a/arch/arm/mach-imx/Kconfig
> > +++ b/arch/arm/mach-imx/Kconfig
> > @@ -834,6 +834,7 @@ comment "i.MX6 family:"
> >  
> >  config SOC_IMX6Q
> >  	bool "i.MX6 Quad support"
> > +	select ARCH_HAS_CPUFREQ
> >  	select ARM_GIC
> >  	select CACHE_L2X0
> >  	select CPU_V7
> > diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> > index 9cf630a..2dfe4a7 100644
> > --- a/arch/arm/mach-imx/Makefile
> > +++ b/arch/arm/mach-imx/Makefile
> > @@ -72,7 +72,7 @@ AFLAGS_head-v7.o :=-Wa,-march=armv7-a
> >  obj-$(CONFIG_SMP) += platsmp.o
> >  obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
> >  obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
> > -obj-$(CONFIG_SOC_IMX6Q) += clock-imx6q.o mach-imx6q.o pm-imx6q.o
> > +obj-$(CONFIG_SOC_IMX6Q) += clock-imx6q.o mach-imx6q.o pm-imx6q.o cpu_op-imx6q.o
> >  
> >  # i.MX5 based machines
> >  obj-$(CONFIG_MACH_MX51_BABBAGE) += mach-mx51_babbage.o
> > diff --git a/arch/arm/mach-imx/cpu_op-imx6q.c b/arch/arm/mach-imx/cpu_op-imx6q.c
> > new file mode 100644
> > index 0000000..d24e081
> > --- /dev/null
> > +++ b/arch/arm/mach-imx/cpu_op-imx6q.c
> > @@ -0,0 +1,69 @@
> > +/*
> > + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
> > + */
> > +
> > +/*
> > + * The code contained herein is licensed under the GNU General Public
> > + * License. You may obtain a copy of the GNU General Public License
> > + * Version 2 or later at the following locations:
> > + *
> > + * http://www.opensource.org/licenses/gpl-license.html
> > + * http://www.gnu.org/copyleft/gpl.html
> > + */
> > +
> > +#include <linux/types.h>
> > +#include <linux/kernel.h>
> > +#include <linux/string.h>
> > +#include <linux/of.h>
> > +#include <mach/hardware.h>
> > +
> > +static int arm_max_freq_idx;
> 
> This is only used in mx6q_get_cpu_op()
I'll move to local var
> 
> Also shouldn't this be initialized with 1? From what you
> said 800MHz is safe for all boards whereas 1GHz is not.
I'll fix it in next version.

Thanks
Richard
> 
> Sascha
> 
> > +
> > +/* operating point(op): 0 - 1GHz; 1 - 800MHz, 3 - 400MHz, 4  - 160MHz */
> > +static struct cpu_op mx6q_cpu_op[] = {
> > +	{
> > +		.cpu_rate = 996000000,
> > +		.cpu_voltage = 1225000,
> > +	},
> > +	{
> > +		.cpu_rate = 792000000,
> > +		.cpu_voltage = 1100000,
> > +	},
> > +	{
> > +		.cpu_rate = 396000000,
> > +		.cpu_voltage = 950000,
> > +	},
> > +	{
> > +		.cpu_rate = 198000000,
> > +		.cpu_voltage = 850000,
> > +	},
> > +};
> > +
> > +struct cpu_op *mx6q_get_cpu_op(int *op)
> > +{
> > +	struct device_node *cpu0;
> > +	u32 val;
> > +	int i;
> > +
> > +	cpu0 = of_find_node_by_path("/cpus/cpu at 0");
> > +	if (cpu0 && !of_property_read_u32(cpu0, "clock-frequency", &val)) {
> > +		for (i = 0; i < ARRAY_SIZE(mx6q_cpu_op); i++) {
> > +			if (val >= mx6q_cpu_op[i].cpu_rate) {
> > +				arm_max_freq_idx = i;
> > +				break;
> > +			}
> > +		}
> > +	}
> > +	if (cpu0)
> > +		of_node_put(cpu0);
> > +	*op = ARRAY_SIZE(mx6q_cpu_op) - arm_max_freq_idx;
> > +	return mx6q_cpu_op + arm_max_freq_idx;
> > +}
> > +
> > +static int __init mx6q_cpu_op_init(void)
> > +{
> > +	get_cpu_op = mx6q_get_cpu_op;
> > +	return 0;
> > +}
> > +
> > +core_initcall(mx6q_cpu_op_init);
> > -- 
> > 1.7.5.4
> > 
> > 
> > 
> 
> -- 
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