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authorAndre Przywara <andre.przywara@arm.com>2021-07-31 21:48:44 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2021-08-06 19:45:25 +0800
commitb83c2d92be719bf7b1d24ac02aaa53db3991ea58 (patch)
tree9d6ae6cb9f259d0b987e386889095098c9c691b2 /drivers/firmware
parent5441a07a127f106c9936e4f9fa1a8a93e3f31828 (diff)
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: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/smccc/smccc.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
index 9f937b125ab0..60ccf3e90d7d 100644
--- a/drivers/firmware/smccc/smccc.c
+++ b/drivers/firmware/smccc/smccc.c
@@ -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);