Subject: [RFC PATCH 4/5] ARM: psci: Add support for system reboot and poweroff

From: [email-masked] (Rob Herring)
Date: Wed, 16 Oct 2013 17:17:24 -0500

On 10/16/2013 12:02 PM, Anup Patel wrote:
> We have PSCI SYSTEM_OFF and SYSTEM_RESET function call emulation
> available when running as Guest using KVM ARM.
> 
> This patch implements system reboot and poweroff using PSCI
> SYSTEM_OFF and SYSTEM_RESET.

I've done a similar patch [1] which also needs binding documentation to
go with it. The last version of which there is no agreement on is here [2].

Rob

[1] http://www.spinics.net/lists/arm-kernel/msg262217.html
[2] http://www.spinics.net/lists/devicetree/msg05348.html

>
> 
> Signed-off-by: Anup Patel <[email-masked]>
> Signed-off-by: Pranavkumar Sawargaonkar <[email-masked]>
> ---
>  arch/arm/kernel/psci.c |   36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
> index 4693188..30d9d65 100644
> --- a/arch/arm/kernel/psci.c
> +++ b/arch/arm/kernel/psci.c
> @@ -17,11 +17,13 @@
>  
>  #include <linux/init.h>
>  #include <linux/of.h>
> +#include <linux/pm.h>
>  
>  #include <asm/compiler.h>
>  #include <asm/errno.h>
>  #include <asm/opcodes-sec.h>
>  #include <asm/opcodes-virt.h>
> +#include <asm/system_misc.h>
>  #include <asm/psci.h>
>  
>  struct psci_operations psci_ops;
> @@ -33,6 +35,8 @@ enum psci_function {
>  	PSCI_FN_CPU_ON,
>  	PSCI_FN_CPU_OFF,
>  	PSCI_FN_MIGRATE,
> +	PSCI_FN_SYSTEM_OFF,
> +	PSCI_FN_SYSTEM_RESET,
>  	PSCI_FN_MAX,
>  };
>  
> @@ -153,6 +157,28 @@ static int psci_migrate(unsigned long cpuid)
>  	return psci_to_linux_errno(err);
>  }
>  
> +static void psci_power_off(void)
> +{
> +	int err;
> +	u32 fn;
> +
> +	fn = psci_function_id[PSCI_FN_SYSTEM_OFF];
> +	err = invoke_psci_fn(fn, 0, 0, 0);
> +	if (err)
> +		pr_warning("%s: failed\n", __func__);
> +}
> +
> +static void psci_restart(enum reboot_mode reboot_mode, const char *cmd)
> +{
> +	int err;
> +	u32 fn;
> +
> +	fn = psci_function_id[PSCI_FN_SYSTEM_RESET];
> +	err = invoke_psci_fn(fn, 0, 0, 0);
> +	if (err)
> +		pr_warning("%s: failed\n", __func__);
> +}
> +
>  static const struct of_device_id psci_of_match[] __initconst = {
>  	{ .compatible = "arm,psci",	},
>  	{},
> @@ -204,6 +230,16 @@ void __init psci_init(void)
>  		psci_ops.migrate = psci_migrate;
>  	}
>  
> +	if (!of_property_read_u32(np, "system_off", &id)) {
> +		psci_function_id[PSCI_FN_SYSTEM_OFF] = id;
> +		pm_power_off = psci_power_off;
> +	}
> +
> +	if (!of_property_read_u32(np, "system_reset", &id)) {
> +		psci_function_id[PSCI_FN_SYSTEM_RESET] = id;
> +		arm_pm_restart = psci_restart;
> +	}
> +
>  out_put_node:
>  	of_node_put(np);
>  	return;
>