[PATCH V2] ARM: imx: add cpuidle support for i.mx6ul

[Shawn Guo]

On Wed, Aug 05, 2015 at 01:59:24AM +0800, Anson Huang wrote:
> This patch introduces an independent cpuidle driver for
> i.MX6UL, totally 3 levels of cpuidle are supported as below:
> 
> 1. ARM WFI;
> 2. SOC in WAIT mode;
> 3. SOC in WAIT mode + ARM power off.
> 
> Signed-off-by: Anson Huang <b20788 at freescale.com>

>From what I've seen, it's almost identical to cpuidle-imx6sx driver.
We should consider to share the driver code rather than creating another
one with a lot of duplicating code.

Shawn

> ---
> change from V1:
> 	remove CPUIDLE_FLAG_TIMER_STOP flag as i.MX6UL does
> NOT use local timer.
>  arch/arm/mach-imx/Makefile         |   1 +
>  arch/arm/mach-imx/cpuidle-imx6ul.c | 105 +++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-imx/cpuidle.h        |   5 ++
>  arch/arm/mach-imx/mach-imx6ul.c    |   8 +++
>  4 files changed, 119 insertions(+)
>  create mode 100644 arch/arm/mach-imx/cpuidle-imx6ul.c
> 
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index fb689d8..1d7df9c 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_SOC_IMX5) += cpuidle-imx5.o
>  obj-$(CONFIG_SOC_IMX6Q) += cpuidle-imx6q.o
>  obj-$(CONFIG_SOC_IMX6SL) += cpuidle-imx6sl.o
>  obj-$(CONFIG_SOC_IMX6SX) += cpuidle-imx6sx.o
> +obj-$(CONFIG_SOC_IMX6UL) += cpuidle-imx6ul.o
>  endif
>  
>  ifdef CONFIG_SND_IMX_SOC
> diff --git a/arch/arm/mach-imx/cpuidle-imx6ul.c b/arch/arm/mach-imx/cpuidle-imx6ul.c
> new file mode 100644
> index 0000000..27ab28a
> --- /dev/null
> +++ b/arch/arm/mach-imx/cpuidle-imx6ul.c
> @@ -0,0 +1,105 @@
> +/*
> + * Copyright (C) 2015 Freescale Semiconductor, Inc.
> + *
> + * 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/cpuidle.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/module.h>
> +#include <asm/cacheflush.h>
> +#include <asm/cpuidle.h>
> +#include <asm/suspend.h>
> +
> +#include "common.h"
> +#include "cpuidle.h"
> +
> +static int imx6ul_idle_finish(unsigned long val)
> +{
> +	flush_cache_all();
> +	cpu_do_idle();
> +
> +	return 0;
> +}
> +
> +static int imx6ul_enter_wait(struct cpuidle_device *dev,
> +			    struct cpuidle_driver *drv, int index)
> +{
> +	imx6_set_lpm(WAIT_UNCLOCKED);
> +
> +	switch (index) {
> +	case 1:
> +		cpu_do_idle();
> +		break;
> +	case 2:
> +		imx6_enable_rbc(true);
> +		imx_gpc_set_arm_power_in_lpm(true);
> +		imx_set_cpu_jump(0, v7_cpu_resume);
> +		/* Need to notify there is a cpu pm operation. */
> +		cpu_pm_enter();
> +		cpu_cluster_pm_enter();
> +
> +		cpu_suspend(0, imx6ul_idle_finish);
> +
> +		cpu_cluster_pm_exit();
> +		cpu_pm_exit();
> +		imx_gpc_set_arm_power_in_lpm(false);
> +		imx6_enable_rbc(false);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	imx6_set_lpm(WAIT_CLOCKED);
> +
> +	return index;
> +}
> +
> +static struct cpuidle_driver imx6ul_cpuidle_driver = {
> +	.name = "imx6ul_cpuidle",
> +	.owner = THIS_MODULE,
> +	.states = {
> +		/* WFI */
> +		ARM_CPUIDLE_WFI_STATE,
> +		/* WAIT */
> +		{
> +			.exit_latency = 50,
> +			.target_residency = 75,
> +			.enter = imx6ul_enter_wait,
> +			.name = "WAIT",
> +			.desc = "Clock off",
> +		},
> +		/* WAIT + ARM power off  */
> +		{
> +			/*
> +			 * ARM gating 31us * 5 + RBC clear 65us
> +			 * and some margin for SW execution, here set it
> +			 * to 300us.
> +			 */
> +			.exit_latency = 300,
> +			.target_residency = 500,
> +			.enter = imx6ul_enter_wait,
> +			.name = "LOW-POWER-IDLE",
> +			.desc = "ARM power off",
> +		},
> +	},
> +	.state_count = 3,
> +	.safe_state_index = 0,
> +};
> +
> +int __init imx6ul_cpuidle_init(void)
> +{
> +	imx6_enable_rbc(false);
> +	/*
> +	 * set ARM power up/down timing to the fastest,
> +	 * sw2iso and sw can be set to one 32K cycle = 31us
> +	 * except for power up sw2iso which need to be
> +	 * larger than LDO ramp up time.
> +	 */
> +	imx_gpc_set_arm_power_up_timing(2, 1);
> +	imx_gpc_set_arm_power_down_timing(1, 1);
> +
> +	return cpuidle_register(&imx6ul_cpuidle_driver, NULL);
> +}
> diff --git a/arch/arm/mach-imx/cpuidle.h b/arch/arm/mach-imx/cpuidle.h
> index f914012..4dcf71d 100644
> --- a/arch/arm/mach-imx/cpuidle.h
> +++ b/arch/arm/mach-imx/cpuidle.h
> @@ -15,6 +15,7 @@ extern int imx5_cpuidle_init(void);
>  extern int imx6q_cpuidle_init(void);
>  extern int imx6sl_cpuidle_init(void);
>  extern int imx6sx_cpuidle_init(void);
> +extern int imx6ul_cpuidle_init(void);
>  #else
>  static inline int imx5_cpuidle_init(void)
>  {
> @@ -32,4 +33,8 @@ static inline int imx6sx_cpuidle_init(void)
>  {
>  	return 0;
>  }
> +static inline int imx6ul_cpuidle_init(void)
> +{
> +	return 0;
> +}
>  #endif
> diff --git a/arch/arm/mach-imx/mach-imx6ul.c b/arch/arm/mach-imx/mach-imx6ul.c
> index f206506..0f4b95c 100644
> --- a/arch/arm/mach-imx/mach-imx6ul.c
> +++ b/arch/arm/mach-imx/mach-imx6ul.c
> @@ -11,6 +11,7 @@
>  #include <asm/mach/map.h>
>  
>  #include "common.h"
> +#include "cpuidle.h"
>  
>  static void __init imx6ul_init_machine(void)
>  {
> @@ -29,6 +30,12 @@ static void __init imx6ul_init_irq(void)
>  	imx_init_revision_from_anatop();
>  	imx_src_init();
>  	irqchip_init();
> +	imx6_pm_ccm_init("fsl,imx6ul-ccm");
> +}
> +
> +static void __init imx6ul_init_late(void)
> +{
> +	imx6ul_cpuidle_init();
>  }
>  
>  static const char *imx6ul_dt_compat[] __initconst = {
> @@ -40,4 +47,5 @@ DT_MACHINE_START(IMX6UL, "Freescale i.MX6 Ultralite (Device Tree)")
>  	.init_irq	= imx6ul_init_irq,
>  	.init_machine	= imx6ul_init_machine,
>  	.dt_compat	= imx6ul_dt_compat,
> +	.init_late	= imx6ul_init_late,
>  MACHINE_END
> -- 
> 1.9.1
>