Add driver providing kernel-side support for the Random Number Generator hardware found on Mediatek SoCs which have a driver in ARM TrustedFirmware-A allowing Linux to read random numbers using a non-standard vendor-defined Secure Monitor Call. Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx> --- MAINTAINERS | 1 + drivers/char/hw_random/Kconfig | 16 +++++++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/mtk-rng-v2.c | 74 +++++++++++++++++++++++++++++ 4 files changed, 92 insertions(+) create mode 100644 drivers/char/hw_random/mtk-rng-v2.c diff --git a/MAINTAINERS b/MAINTAINERS index be167c695c64..90d82aba6d73 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13148,6 +13148,7 @@ F: drivers/leds/leds-mt6323.c MEDIATEK RANDOM NUMBER GENERATOR SUPPORT M: Sean Wang <sean.wang@xxxxxxxxxxxx> S: Maintained +F: drivers/char/hw_random/mtk-rng-v2.c F: drivers/char/hw_random/mtk-rng.c MEDIATEK SMI DRIVER diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 4fdf07ae3c54..7c900185486d 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -439,6 +439,22 @@ config HW_RANDOM_MTK If unsure, say Y. +config HW_RANDOM_MTK_V2 + tristate "Mediatek Random Number Generator support (v2/SMC)" + depends on HW_RANDOM + depends on (ARM64 && ARCH_MEDIATEK) || COMPILE_TEST + default y + help + This driver provides kernel-side support for the Random Number + Generator hardware found on Mediatek SoCs which have a driver + in ARM TrustedFirmware-A allowing Linux to read using a non- + standard vendor-defined Secure Monitor Call. + + To compile this driver as a module, choose M here. the + module will be called mtk-rng-v2. + + If unsure, say Y. + config HW_RANDOM_S390 tristate "S390 True Random Number Generator support" depends on S390 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 09bde4a0f971..ba319c509e86 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o +obj-$(CONFIG_HW_RANDOM_MTK_V2) += mtk-rng-v2.o obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o diff --git a/drivers/char/hw_random/mtk-rng-v2.c b/drivers/char/hw_random/mtk-rng-v2.c new file mode 100644 index 000000000000..6e61f4361d9e --- /dev/null +++ b/drivers/char/hw_random/mtk-rng-v2.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for Mediatek Hardware Random Number Generator (v2/SMCC) + * + * Copyright (C) 2023 Daniel Golle <daniel@xxxxxxxxxxxxxx> + * based on patch from Mingming Su <Mingming.Su@xxxxxxxxxxxx> + */ +#define MTK_RNG_DEV KBUILD_MODNAME + +#include <linux/arm-smccc.h> +#include <linux/err.h> +#include <linux/hw_random.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/soc/mediatek/mtk_sip_svc.h> + +#define MTK_SIP_KERNEL_GET_RND MTK_SIP_SMC_CMD(0x550) + +static int mtk_rng_v2_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct arm_smccc_res res; + int retval = 0; + + while (max >= sizeof(u32)) { + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, 0, 0, 0, 0, 0, 0, 0, + &res); + if (res.a0) + break; + + *(u32 *)buf = res.a1; + retval += sizeof(u32); + buf += sizeof(u32); + max -= sizeof(u32); + } + + return retval || !wait ? retval : -EIO; +} + +static int mtk_rng_v2_probe(struct platform_device *pdev) +{ + struct hwrng *trng; + + trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL); + if (!trng) + return -ENOMEM; + + trng->name = pdev->name; + trng->read = mtk_rng_v2_read; + trng->quality = 900; + + return devm_hwrng_register(&pdev->dev, trng); +} + +static const struct of_device_id mtk_rng_v2_match[] = { + { .compatible = "mediatek,mt7981-rng" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mtk_rng_v2_match); + +static struct platform_driver mtk_rng_v2_driver = { + .probe = mtk_rng_v2_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = mtk_rng_v2_match, + }, +}; +module_platform_driver(mtk_rng_v2_driver); + +MODULE_DESCRIPTION("Mediatek Random Number Generator Driver (v2/SMC)"); +MODULE_AUTHOR("Daniel Golle <daniel@xxxxxxxxxxxxxx>"); +MODULE_LICENSE("GPL"); base-commit: 9d9019bcea1aac7eed64a1a4966282b6b7b141c8 -- 2.39.1