Re: [PATCH v2 11/12] cpuidle: mvebu: Add initial CPU idle support for Armada 370/XP SoC

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 09/13/2013 12:06 PM, Gregory CLEMENT wrote:
> Add the wfi, cpu idle and cpu deep idle power states support for the
> Armada XP SoCs.
> 
> All the latencies and the power consumption values used at the
> "armada_370_xp_idle_driver" structure are preliminary and will be
> modified in the future after running some measurements and analysis.
> 
> Based on the work of Nadav Haklai.
> 
> Signed-off-by: Nadav Haklai <nadavh@marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
>  drivers/cpuidle/Kconfig.arm             |   5 ++
>  drivers/cpuidle/Makefile                |   1 +
>  drivers/cpuidle/cpuidle-armada-370-xp.c | 103 ++++++++++++++++++++++++++++++++
>  drivers/cpuidle/suspend-armada-370-xp.S |  91 ++++++++++++++++++++++++++++

Somehow, you will have to move "suspend-armada-370-xp.S" into arch/arm.

>  4 files changed, 200 insertions(+)
>  create mode 100644 drivers/cpuidle/cpuidle-armada-370-xp.c
>  create mode 100644 drivers/cpuidle/suspend-armada-370-xp.S
> 
> diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> index 8e36603..071d960 100644
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm
> @@ -1,6 +1,11 @@
>  #
>  # ARM CPU Idle drivers
>  #
> +config ARM_ARMADA_370_XP_CPUIDLE
> +	bool "CPU Idle Driver for Armada 370/XP family processors"
> +	depends on ARCH_MVEBU
> +	help
> +	  Select this to enable cpuidle on Armada 370/XP processors.
>  
>  config ARM_HIGHBANK_CPUIDLE
>  	bool "CPU Idle Driver for Calxeda processors"
> diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
> index cea5ef5..90fc4a6 100644
> --- a/drivers/cpuidle/Makefile
> +++ b/drivers/cpuidle/Makefile
> @@ -7,6 +7,7 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
>  
>  ##################################################################################
>  # ARM SoC drivers
> +obj-$(CONFIG_ARM_ARMADA_370_XP_CPUIDLE) += cpuidle-armada-370-xp.o suspend-armada-370-xp.o
>  obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE)	+= cpuidle-calxeda.o
>  obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
>  obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
> diff --git a/drivers/cpuidle/cpuidle-armada-370-xp.c b/drivers/cpuidle/cpuidle-armada-370-xp.c
> new file mode 100644
> index 0000000..7c78d92
> --- /dev/null
> +++ b/drivers/cpuidle/cpuidle-armada-370-xp.c
> @@ -0,0 +1,103 @@
> +/*
> + * Marvell Armada 370 and Armada XP SoC cpuidle driver
> + *
> + * Copyright (C) 2013 Marvell
> + *
> + * Nadav Haklai <nadavh@marvell.com>
> + * Gregory CLEMENT <gregory.clement@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2.  This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + *
> + * Maintainer: Gregory CLEMENT <gregory.clement@free-electrons.com>
> + */
> +
> +#include <linux/cpuidle.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/suspend.h>
> +#include <asm/suspend.h>
> +#include <linux/smp.h>
> +#include <asm/cpuidle.h>
> +#include <asm/smp_plat.h>
> +#include <linux/armada-370-xp-pmsu.h>
> +
> +#define ARMADA_370_XP_MAX_STATES	3
> +
> +enum mv_pm_states {
> +	WFI = 0,
> +	MV_CPU_IDLE,
> +	MV_CPU_DEEP_IDLE,
> +};
> +
> +extern void v7_flush_dcache_all(void);
> +
> +/* Functions defined in suspend-armada-370-xp.S */
> +int armada_370_xp_cpu_resume(unsigned long);
> +int armada_370_xp_cpu_suspend(unsigned long);
> +
> +static int armada_370_xp_enter_idle(struct cpuidle_device *dev,
> +				struct cpuidle_driver *drv,
> +				int index)
> +{
> +	bool deepidle = false;
> +	unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
> +
> +	armada_370_xp_pmsu_set_start_addr(armada_370_xp_cpu_resume, hw_cpu);
> +
> +	if (index == MV_CPU_DEEP_IDLE)
> +		deepidle = true;

That looks a bit hackish no ? :)

Can't you use the CPUIDLE_DRIVER_FLAGS_MASK to store this information ?

> +	cpu_suspend(deepidle, armada_370_xp_cpu_suspend);
> +
> +	cpu_init();
> +
> +	armada_370_xp_pmsu_idle_restore();
> +
> +	return index;
> +}
> +
> +static struct cpuidle_driver armada_370_xp_idle_driver = {
> +	.name			= "armada_370_xp_idle",
> +	.states[0]		= ARM_CPUIDLE_WFI_STATE,
> +	.states[1]		= {
> +		.enter			= armada_370_xp_enter_idle,
> +		.exit_latency		= 10,
> +		.power_usage		= 50,
> +		.target_residency	= 100,
> +		.flags			= CPUIDLE_FLAG_TIME_VALID,
> +		.name			= "MV CPU IDLE",
> +		.desc			= "CPU power down",
> +	},
> +	.states[2]		= {
> +		.enter			= armada_370_xp_enter_idle,
> +		.exit_latency		= 100,
> +		.power_usage		= 5,
> +		.target_residency	= 1000,
> +		.flags			= CPUIDLE_FLAG_TIME_VALID,
> +		.name			= "MV CPU DEEP IDLE",
> +		.desc			= "CPU and L2 Fabric power down",
> +	},
> +	.state_count = ARMADA_370_XP_MAX_STATES,
> +};

What about the local timers ? Are they shutdown ?

> +
> +static int __init armada_370_xp_cpuidle_init(void)
> +{
> +	if (!of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-pmsu"))
> +		return -ENODEV;
> +
> +	if (!of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric"))
> +		return -ENODEV;
> +
> +	pr_info("Initializing Armada-XP CPU power management ");
> +
> +	armada_370_xp_pmsu_enable_l2_powerdown_onidle();
> +
> +	return cpuidle_register(&armada_370_xp_idle_driver, NULL);
> +}
> +
> +module_init(armada_370_xp_cpuidle_init);

Isn't it possible to replace it by module_platform_driver ? like ux500
or kirkwood ?

Thanks
  -- Daniel

> +MODULE_LICENSE("GPL");

[ ... ]


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