ARM: mx25: Add basic suspend/resume support

From: Fabio Estevam <fabio.estevam@freescale.com>

Tested basic suspend/resume on a mx25pdk:

root@freescale /$ echo mem > /sys/power/state 
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.001 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
Suspending console(s) (use no_console_suspend to debug)

(Press the keypad)

PM: suspend of devices complete after 5.637 msecs
PM: late suspend of devices complete after 1.649 msecs
PM: noirq suspend of devices complete after 1.874 msecs
PM: noirq resume of devices complete after 1.643 msecs
PM: early resume of devices complete after 1.923 msecs
PM: resume of devices complete after 62.884 msecs
Restarting tasks ... done.
fec 50038000.ethernet eth0: Link is Down
fec 50038000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
root@freescale /$ 

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 arch/arm/mach-imx/Makefile   |  2 +-
 arch/arm/mach-imx/imx25-dt.c |  2 ++
 arch/arm/mach-imx/pm-imx25.c | 35 +++++++++++++++++++++++++++++++++++
 arch/arm/mach-imx/pm-imx25.h | 13 +++++++++++++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-imx/pm-imx25.c
 create mode 100644 arch/arm/mach-imx/pm-imx25.h

On Wed, Jun 25, 2014 at 04:19:09PM -0300, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@freescale.com>
> 
> Tested basic suspend/resume on a mx25pdk:
> 
> root@freescale /$ echo mem > /sys/power/state 
> PM: Syncing filesystems ... done.
> Freezing user space processes ... (elapsed 0.001 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> Suspending console(s) (use no_console_suspend to debug)
> 
> (Press the keypad)
> 
> PM: suspend of devices complete after 5.637 msecs
> PM: late suspend of devices complete after 1.649 msecs
> PM: noirq suspend of devices complete after 1.874 msecs
> PM: noirq resume of devices complete after 1.643 msecs
> PM: early resume of devices complete after 1.923 msecs
> PM: resume of devices complete after 62.884 msecs
> Restarting tasks ... done.
> fec 50038000.ethernet eth0: Link is Down
> fec 50038000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
> root@freescale /$ 
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  arch/arm/mach-imx/Makefile   |  2 +-
>  arch/arm/mach-imx/imx25-dt.c |  2 ++
>  arch/arm/mach-imx/pm-imx25.c | 35 +++++++++++++++++++++++++++++++++++
>  arch/arm/mach-imx/pm-imx25.h | 13 +++++++++++++
>  4 files changed, 51 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm/mach-imx/pm-imx25.c
>  create mode 100644 arch/arm/mach-imx/pm-imx25.h
> 
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index a364e20..ddc28d4 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -3,7 +3,7 @@ obj-y := time.o cpu.o system.o irq-common.o
>  obj-$(CONFIG_SOC_IMX1) += clk-imx1.o mm-imx1.o
>  obj-$(CONFIG_SOC_IMX21) += clk-imx21.o mm-imx21.o
>  
> -obj-$(CONFIG_SOC_IMX25) += clk-imx25.o mm-imx25.o ehci-imx25.o cpu-imx25.o
> +obj-$(CONFIG_SOC_IMX25) += clk-imx25.o mm-imx25.o ehci-imx25.o cpu-imx25.o pm-imx25.o
>  
>  obj-$(CONFIG_SOC_IMX27) += cpu-imx27.o pm-imx27.o
>  obj-$(CONFIG_SOC_IMX27) += clk-imx27.o mm-imx27.o ehci-imx27.o
> diff --git a/arch/arm/mach-imx/imx25-dt.c b/arch/arm/mach-imx/imx25-dt.c
> index 42a65e0..39babdf 100644
> --- a/arch/arm/mach-imx/imx25-dt.c
> +++ b/arch/arm/mach-imx/imx25-dt.c
> @@ -16,6 +16,7 @@
>  #include <asm/mach/time.h>
>  #include "common.h"
>  #include "mx25.h"
> +#include "pm-imx25.h"
>  
>  static void __init imx25_dt_init(void)
>  {
> @@ -38,6 +39,7 @@ DT_MACHINE_START(IMX25_DT, "Freescale i.MX25 (Device Tree Support)")
>  	.map_io		= mx25_map_io,
>  	.init_early	= imx25_init_early,
>  	.init_irq	= mx25_init_irq,
> +	.init_late      = mx25_pm_init,

For new code, please use "imx25" constantly for namespace instead of
"mx25".

>  	.init_time	= imx25_timer_init,
>  	.init_machine	= imx25_dt_init,
>  	.dt_compat	= imx25_dt_board_compat,
> diff --git a/arch/arm/mach-imx/pm-imx25.c b/arch/arm/mach-imx/pm-imx25.c
> new file mode 100644
> index 0000000..2463548
> --- /dev/null
> +++ b/arch/arm/mach-imx/pm-imx25.c
> @@ -0,0 +1,35 @@
> +/*
> + * Copyright 2014 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/kernel.h>
> +#include <linux/suspend.h>
> +#include <linux/io.h>
> +#include "pm-imx25.h"
> +
> +static int mx25_suspend_enter(suspend_state_t state)
> +{
> +	switch (state) {
> +	case PM_SUSPEND_MEM:
> +		cpu_do_idle();
> +		break;
> +

Nit: drop this new line ...

> +	default:
> +		return -EINVAL;
> +	}

... and have a new line here.

> +	return 0;
> +}
> +
> +static const struct platform_suspend_ops mx25_suspend_ops = {
> +	.enter = mx25_suspend_enter,
> +	.valid = suspend_valid_only_mem,
> +};
> +
> +void __init mx25_pm_init(void)
> +{
> +	suspend_set_ops(&mx25_suspend_ops);
> +}
> diff --git a/arch/arm/mach-imx/pm-imx25.h b/arch/arm/mach-imx/pm-imx25.h
> new file mode 100644
> index 0000000..41da794
> --- /dev/null
> +++ b/arch/arm/mach-imx/pm-imx25.h
> @@ -0,0 +1,13 @@
> +/*
> + * Copyright 2014 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.
> + */
> +
> +#ifdef CONFIG_PM
> +void mx25_pm_init(void);
> +#else
> +#define mx25_pm_init NULL
> +#endif

Not sure if it's worth a new header merely for this.  Or you plan to add
more stuff later?

Shawn

> -- 
> 1.8.3.2
>