From patchwork Thu Apr 18 12:11:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 13634616 X-Patchwork-Delegate: arnd@arndb.de Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 14D86C04FFF for ; Thu, 18 Apr 2024 12:11:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) id F4127C2BD11; Thu, 18 Apr 2024 12:11:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBEE3C32781; Thu, 18 Apr 2024 12:11:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713442303; bh=ap6u4jJVqsVtbs9MZBwDK1tnlUgtvs4miuNhDed77lo=; h=From:List-Id:To:Cc:Subject:Date:In-Reply-To:References:From; b=cvOU+5BLd+Ubj7Eopndn3YzruZB/G8KixhIeld8UBMKquS291FEWnPklapE+ij/y/ R4ohad71KCXje+83/xwikOju89MPNaCIf5yAqDSK4QinUsVN54MRu6tDw2Z2Je9ACD +psedmmOMtOeRXil96VMO/q9kQJolDJZBs89i8GfVe9E7tDquRXRgEiNxK0aMocedB wGF4gRY4l5bD7necnm2mEOp6C47Oqw/blhZwZ1/tDwDNKGM1SvpKGVHuSUScFQ48O+ aP7/DfYNsDB5uXHEK+JnTHC5FwcTnC+qeRHN0Oz3yaApEUXTuMrFsyAR7p0qHrNQLV WYebr0J1Fbe5g== From: =?utf-8?q?Marek_Beh=C3=BAn?= List-Id: To: Gregory CLEMENT , Arnd Bergmann , soc@kernel.org, Andy Shevchenko , Olivia Mackall , Herbert Xu , Greg Kroah-Hartman , linux-crypto@vger.kernel.org Cc: arm@kernel.org, =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH v6 07/11] platform: cznic: turris-omnia-mcu: Add support for MCU provided TRNG Date: Thu, 18 Apr 2024 14:11:12 +0200 Message-ID: <20240418121116.22184-8-kabel@kernel.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240418121116.22184-1-kabel@kernel.org> References: <20240418121116.22184-1-kabel@kernel.org> MIME-Version: 1.0 Add support for true random number generator provided by the MCU. New Omnia boards come without the Atmel SHA204-A chip. Instead the crypto functionality is provided by new microcontroller, which has a TRNG peripheral. Signed-off-by: Marek Behún --- drivers/platform/cznic/Kconfig | 2 + drivers/platform/cznic/Makefile | 1 + .../platform/cznic/turris-omnia-mcu-base.c | 6 +- .../platform/cznic/turris-omnia-mcu-gpio.c | 2 +- .../platform/cznic/turris-omnia-mcu-trng.c | 89 +++++++++++++++++++ drivers/platform/cznic/turris-omnia-mcu.h | 8 ++ 6 files changed, 106 insertions(+), 2 deletions(-) create mode 100644 drivers/platform/cznic/turris-omnia-mcu-trng.c diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig index e2649cdecc38..750d5f47dba8 100644 --- a/drivers/platform/cznic/Kconfig +++ b/drivers/platform/cznic/Kconfig @@ -19,6 +19,7 @@ config TURRIS_OMNIA_MCU depends on I2C select GPIOLIB select GPIOLIB_IRQCHIP + select HW_RANDOM select RTC_CLASS select WATCHDOG_CORE help @@ -28,6 +29,7 @@ config TURRIS_OMNIA_MCU - board poweroff into true low power mode (with voltage regulators disabled) and the ability to configure wake up from this mode (via rtcwake) + - true random number generator (if available on the MCU) - MCU watchdog - GPIO pins - to get front button press events (the front button can be diff --git a/drivers/platform/cznic/Makefile b/drivers/platform/cznic/Makefile index 687f7718c0a1..eae4c6b341ff 100644 --- a/drivers/platform/cznic/Makefile +++ b/drivers/platform/cznic/Makefile @@ -4,4 +4,5 @@ obj-$(CONFIG_TURRIS_OMNIA_MCU) += turris-omnia-mcu.o turris-omnia-mcu-y := turris-omnia-mcu-base.o turris-omnia-mcu-y += turris-omnia-mcu-gpio.o turris-omnia-mcu-y += turris-omnia-mcu-sys-off-wakeup.o +turris-omnia-mcu-y += turris-omnia-mcu-trng.o turris-omnia-mcu-y += turris-omnia-mcu-watchdog.o diff --git a/drivers/platform/cznic/turris-omnia-mcu-base.c b/drivers/platform/cznic/turris-omnia-mcu-base.c index 5f88119d825c..7fe4a3df93a6 100644 --- a/drivers/platform/cznic/turris-omnia-mcu-base.c +++ b/drivers/platform/cznic/turris-omnia-mcu-base.c @@ -369,7 +369,11 @@ static int omnia_mcu_probe(struct i2c_client *client) if (err) return err; - return omnia_mcu_register_gpiochip(mcu); + err = omnia_mcu_register_gpiochip(mcu); + if (err) + return err; + + return omnia_mcu_register_trng(mcu); } static const struct of_device_id of_omnia_mcu_match[] = { diff --git a/drivers/platform/cznic/turris-omnia-mcu-gpio.c b/drivers/platform/cznic/turris-omnia-mcu-gpio.c index b3b203f0d2b9..625018ca82cc 100644 --- a/drivers/platform/cznic/turris-omnia-mcu-gpio.c +++ b/drivers/platform/cznic/turris-omnia-mcu-gpio.c @@ -162,7 +162,7 @@ static const struct omnia_gpio { }; /* mapping from interrupts to indexes of GPIOs in the omnia_gpios array */ -static const u8 omnia_int_to_gpio_idx[32] = { +const u8 omnia_int_to_gpio_idx[32] = { [__bf_shf(INT_CARD_DET)] = 4, [__bf_shf(INT_MSATA_IND)] = 5, [__bf_shf(INT_USB30_OVC)] = 6, diff --git a/drivers/platform/cznic/turris-omnia-mcu-trng.c b/drivers/platform/cznic/turris-omnia-mcu-trng.c new file mode 100644 index 000000000000..24fa8cb5d522 --- /dev/null +++ b/drivers/platform/cznic/turris-omnia-mcu-trng.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CZ.NIC's Turris Omnia MCU TRNG driver + * + * 2024 by Marek Behún + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "turris-omnia-mcu.h" + +#define CMD_TRNG_MAX_ENTROPY_LEN 64 + +static irqreturn_t omnia_trng_irq_handler(int irq, void *dev_id) +{ + struct omnia_mcu *mcu = dev_id; + + complete(&mcu->trng_completion); + + return IRQ_HANDLED; +} + +static int omnia_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct omnia_mcu *mcu = (struct omnia_mcu *)rng->priv; + u8 reply[1 + CMD_TRNG_MAX_ENTROPY_LEN]; + int err, bytes; + + if (!wait && !completion_done(&mcu->trng_completion)) + return 0; + + do { + if (wait_for_completion_interruptible(&mcu->trng_completion)) + return -EINTR; + + err = omnia_cmd_read(mcu->client, CMD_TRNG_COLLECT_ENTROPY, + reply, sizeof(reply)); + if (err) + return err; + + bytes = min3(reply[0], max, CMD_TRNG_MAX_ENTROPY_LEN); + } while (wait && !bytes); + + memcpy(data, &reply[1], bytes); + + return bytes; +} + +int omnia_mcu_register_trng(struct omnia_mcu *mcu) +{ + struct device *dev = &mcu->client->dev; + int irq, err; + u8 irq_idx; + + if (!(mcu->features & FEAT_TRNG)) + return 0; + + irq_idx = omnia_int_to_gpio_idx[__bf_shf(INT_TRNG)]; + irq = devm_irq_create_mapping(dev, mcu->gc.irq.domain, irq_idx); + if (irq < 0) + return dev_err_probe(dev, irq, "Cannot map TRNG IRQ\n"); + + init_completion(&mcu->trng_completion); + + err = devm_request_threaded_irq(dev, irq, NULL, omnia_trng_irq_handler, + IRQF_ONESHOT, "turris-omnia-mcu-trng", + mcu); + if (err) + return dev_err_probe(dev, err, "Cannot request TRNG IRQ\n"); + + mcu->trng.name = "turris-omnia-mcu-trng"; + mcu->trng.read = omnia_trng_read; + mcu->trng.priv = (unsigned long)mcu; + + err = devm_hwrng_register(dev, &mcu->trng); + if (err) + return dev_err_probe(dev, err, "Cannot register TRNG\n"); + + return 0; +} diff --git a/drivers/platform/cznic/turris-omnia-mcu.h b/drivers/platform/cznic/turris-omnia-mcu.h index 1838cb3d636e..e0cf10f8c32e 100644 --- a/drivers/platform/cznic/turris-omnia-mcu.h +++ b/drivers/platform/cznic/turris-omnia-mcu.h @@ -9,7 +9,9 @@ #define __TURRIS_OMNIA_MCU_H #include +#include #include +#include #include #include #include @@ -45,6 +47,10 @@ struct omnia_mcu { /* MCU watchdog */ struct watchdog_device wdt; + + /* true random number generator */ + struct hwrng trng; + struct completion trng_completion; }; int omnia_cmd_write_read(const struct i2c_client *client, @@ -147,11 +153,13 @@ static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd) return err ?: reply; } +extern const u8 omnia_int_to_gpio_idx[32]; extern const struct attribute_group omnia_mcu_gpio_group; extern const struct attribute_group omnia_mcu_poweroff_group; int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu); int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu); +int omnia_mcu_register_trng(struct omnia_mcu *mcu); int omnia_mcu_register_watchdog(struct omnia_mcu *mcu); #endif /* __TURRIS_OMNIA_MCU_H */