Commit b83c2d92 authored by Andre Przywara's avatar Andre Przywara Committed by Herbert Xu
Browse files

firmware: smccc: Register smccc_trng platform device 



At the moment we probe for the Random Number Generator SMCCC service,
and use that in the core code (arch_get_random). However the hardware
entropy can also be useful to access from userland, and be it to assess
its quality.

Register a platform device when the SMCCC TRNG service is detected, to
allow a hw_random driver to hook onto this.

The function registering the device is deliberately made in a way which
allows expansion, so other services that could be exposed via a platform
device (or some other interface), can be added here easily.

Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 5441a07a

drivers/firmware/smccc/smccc.c

+17 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/init.h>

#include <linux/arm-smccc.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <asm/archrandom.h>



static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
@@ -42,3 +43,19 @@ u32 arm_smccc_get_version(void) 
	return smccc_version;

}

EXPORT_SYMBOL_GPL(arm_smccc_get_version);



static int __init smccc_devices_init(void)

{

	struct platform_device *pdev;



	if (smccc_trng_available) {

		pdev = platform_device_register_simple("smccc_trng", -1,

						       NULL, 0);

		if (IS_ERR(pdev))

			pr_err("smccc_trng: could not register device: %ld\n",

			       PTR_ERR(pdev));

	}



	return 0;

}

device_initcall(smccc_devices_init);