| Message ID | b5036408088f2a448b303d6bc6f6f3cc52702dc5.1720830725.git.daniel@makrotopia.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | hwrng: add hwrng support for Rockchip RK3568 | expand |
Daniel Golle <daniel@makrotopia.org> writes: > This message was sent from outside of Texas Instruments. > Do not click links or open attachments unless you recognize the source of this email and know the content is safe. If you wish > to report this message to IT Security, please forward the message as an attachment to phishing@list.ti.com > > From: Aurelien Jarno <aurelien@aurel32.net> > > Rockchip SoCs used to have a random number generator as part of their > crypto device, and support for it has to be added to the corresponding > driver. However newer Rockchip SoCs like the RK3568 have an independent > True Random Number Generator device. This patch adds a driver for it, > greatly inspired from the downstream driver. > > The TRNG device does not seem to have a signal conditionner and the FIPS > 140-2 test returns a lot of failures. They can be reduced by increasing > RK_RNG_SAMPLE_CNT, in a tradeoff between quality and speed. This value > has been adjusted to get ~90% of successes and the quality value has > been set accordingly. > > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> > [daniel@makrotpia.org: code style fixes] > Signed-off-by: Daniel Golle <daniel@makrotopia.org> > Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > --- > MAINTAINERS | 1 + > drivers/char/hw_random/Kconfig | 14 ++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/rockchip-rng.c | 220 ++++++++++++++++++++++++++ > 4 files changed, 236 insertions(+) > create mode 100644 drivers/char/hw_random/rockchip-rng.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 7b2b8b1f526c..2745cfe56774 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -19698,6 +19698,7 @@ M: Daniel Golle <daniel@makrotopia.org> > M: Aurelien Jarno <aurelien@aurel32.net> > S: Maintained > F: Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml > +F: drivers/char/hw_random/rockchip-rng.c > > ROCKCHIP RASTER 2D GRAPHIC ACCELERATION UNIT DRIVER > M: Jacob Chen <jacob-chen@iotwrt.com> > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > index 442c40efb200..2b62cd08f91a 100644 > --- a/drivers/char/hw_random/Kconfig > +++ b/drivers/char/hw_random/Kconfig > @@ -573,6 +573,20 @@ config HW_RANDOM_JH7110 > To compile this driver as a module, choose M here. > The module will be called jh7110-trng. > > +config HW_RANDOM_ROCKCHIP > + tristate "Rockchip True Random Number Generator" > + depends on HW_RANDOM && (ARCH_ROCKCHIP || COMPILE_TEST) > + depends on HAS_IOMEM > + default HW_RANDOM > + help > + This driver provides kernel-side support for the True Random Number > + Generator hardware found on some Rockchip SoC like RK3566 or RK3568. > + > + To compile this driver as a module, choose M here: the > + module will be called rockchip-rng. > + > + If unsure, say Y. > + > endif # HW_RANDOM > > config UML_RANDOM > diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile > index 32549a1186dc..01f012eab440 100644 > --- a/drivers/char/hw_random/Makefile > +++ b/drivers/char/hw_random/Makefile > @@ -48,4 +48,5 @@ obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o > obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o > obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o > obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o > +obj-$(CONFIG_HW_RANDOM_ROCKCHIP) += rockchip-rng.o > obj-$(CONFIG_HW_RANDOM_JH7110) += jh7110-trng.o > diff --git a/drivers/char/hw_random/rockchip-rng.c b/drivers/char/hw_random/rockchip-rng.c > new file mode 100644 > index 000000000000..7e45e9880e3a > --- /dev/null > +++ b/drivers/char/hw_random/rockchip-rng.c > @@ -0,0 +1,220 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * rockchip-rng.c True Random Number Generator driver for Rockchip RK3568 SoC > + * > + * Copyright (c) 2018, Fuzhou Rockchip Electronics Co., Ltd. > + * Copyright (c) 2022, Aurelien Jarno > + * Authors: > + * Lin Jinhan <troy.lin@rock-chips.com> > + * Aurelien Jarno <aurelien@aurel32.net> > + */ > +#include <linux/clk.h> > +#include <linux/hw_random.h> > +#include <linux/io.h> > +#include <linux/iopoll.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > +#include <linux/reset.h> > +#include <linux/slab.h> > + > +#define RK_RNG_AUTOSUSPEND_DELAY 100 > +#define RK_RNG_MAX_BYTE 32 > +#define RK_RNG_POLL_PERIOD_US 100 > +#define RK_RNG_POLL_TIMEOUT_US 10000 > + > +/* > + * TRNG collects osc ring output bit every RK_RNG_SAMPLE_CNT time. The value is > + * a tradeoff between speed and quality and has been adjusted to get a quality > + * of ~900 (~90% of FIPS 140-2 successes). > + */ > +#define RK_RNG_SAMPLE_CNT 1000 > + > +/* TRNG registers from RK3568 TRM-Part2, section 5.4.1 */ > +#define TRNG_RST_CTL 0x0004 > +#define TRNG_RNG_CTL 0x0400 > +#define TRNG_RNG_CTL_LEN_64_BIT (0x00 << 4) > +#define TRNG_RNG_CTL_LEN_128_BIT (0x01 << 4) > +#define TRNG_RNG_CTL_LEN_192_BIT (0x02 << 4) > +#define TRNG_RNG_CTL_LEN_256_BIT (0x03 << 4) > +#define TRNG_RNG_CTL_OSC_RING_SPEED_0 (0x00 << 2) > +#define TRNG_RNG_CTL_OSC_RING_SPEED_1 (0x01 << 2) > +#define TRNG_RNG_CTL_OSC_RING_SPEED_2 (0x02 << 2) > +#define TRNG_RNG_CTL_OSC_RING_SPEED_3 (0x03 << 2) > +#define TRNG_RNG_CTL_ENABLE BIT(1) > +#define TRNG_RNG_CTL_START BIT(0) > +#define TRNG_RNG_SAMPLE_CNT 0x0404 > +#define TRNG_RNG_DOUT 0x0410 > + > +struct rk_rng { > + struct hwrng rng; > + void __iomem *base; > + struct reset_control *rst; > + int clk_num; > + struct clk_bulk_data *clk_bulks; > +}; > + > +static int rk_rng_init(struct hwrng *rng) > +{ > + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); > + int ret; > + > + /* start clocks */ > + ret = clk_bulk_prepare_enable(rk_rng->clk_num, rk_rng->clk_bulks); > + if (ret < 0) { > + dev_err((struct device *) rk_rng->rng.priv, > + "Failed to enable clks %d\n", ret); > + return ret; > + } > + > + /* set the sample period */ > + writel(RK_RNG_SAMPLE_CNT, rk_rng->base + TRNG_RNG_SAMPLE_CNT); > + > + /* set osc ring speed and enable it */ > + writel(TRNG_RNG_CTL_LEN_256_BIT | > + TRNG_RNG_CTL_OSC_RING_SPEED_0 | > + TRNG_RNG_CTL_ENABLE, > + rk_rng->base + TRNG_RNG_CTL); > + > + return 0; > +} > + > +static void rk_rng_cleanup(struct hwrng *rng) > +{ > + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); > + > + /* stop TRNG */ > + writel(0, rk_rng->base + TRNG_RNG_CTL); > + > + /* stop clocks */ > + clk_bulk_disable_unprepare(rk_rng->clk_num, rk_rng->clk_bulks); > +} > + > +static int rk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > +{ > + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); > + size_t to_read = min_t(size_t, max, RK_RNG_MAX_BYTE); > + u32 reg; > + int ret = 0; > + > + ret = pm_runtime_resume_and_get((struct device *) rk_rng->rng.priv); > + if (ret < 0) > + return ret; > + > + /* Start collecting random data */ > + writel(TRNG_RNG_CTL_START, rk_rng->base + TRNG_RNG_CTL); > + > + ret = readl_poll_timeout(rk_rng->base + TRNG_RNG_CTL, reg, > + !(reg & TRNG_RNG_CTL_START), > + RK_RNG_POLL_PERIOD_US, > + RK_RNG_POLL_TIMEOUT_US); > + if (ret < 0) > + goto out; > + > + /* Read random data stored in the registers */ > + memcpy_fromio(buf, rk_rng->base + TRNG_RNG_DOUT, to_read); > +out: > + pm_runtime_mark_last_busy((struct device *) rk_rng->rng.priv); > + pm_runtime_put_sync_autosuspend((struct device *) rk_rng->rng.priv); > + > + return (ret < 0) ? ret : to_read; Do we really need to check ret < 0 here? readl_poll_timeout returns either 0 or -ve. return ret ? ret : to_read; would work as well. we save extra evaluation of (ret<0). Let me know what you think. Kamlesh > +} > + > +static int rk_rng_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct rk_rng *rk_rng; > + int ret; > + > + rk_rng = devm_kzalloc(dev, sizeof(*rk_rng), GFP_KERNEL); > + if (!rk_rng) > + return -ENOMEM; > + > + rk_rng->base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(rk_rng->base)) > + return PTR_ERR(rk_rng->base); > + > + rk_rng->clk_num = devm_clk_bulk_get_all(dev, &rk_rng->clk_bulks); > + if (rk_rng->clk_num < 0) > + return dev_err_probe(dev, rk_rng->clk_num, > + "Failed to get clks property\n"); > + > + rk_rng->rst = devm_reset_control_array_get_exclusive(&pdev->dev); > + if (IS_ERR(rk_rng->rst)) > + return dev_err_probe(dev, PTR_ERR(rk_rng->rst), > + "Failed to get reset property\n"); > + > + reset_control_assert(rk_rng->rst); > + udelay(2); > + reset_control_deassert(rk_rng->rst); > + > + platform_set_drvdata(pdev, rk_rng); > + > + rk_rng->rng.name = dev_driver_string(dev); > + if (!IS_ENABLED(CONFIG_PM)) { > + rk_rng->rng.init = rk_rng_init; > + rk_rng->rng.cleanup = rk_rng_cleanup; > + } > + rk_rng->rng.read = rk_rng_read; > + rk_rng->rng.priv = (unsigned long) dev; > + rk_rng->rng.quality = 900; > + > + pm_runtime_set_autosuspend_delay(dev, RK_RNG_AUTOSUSPEND_DELAY); > + pm_runtime_use_autosuspend(dev); > + devm_pm_runtime_enable(dev); > + > + ret = devm_hwrng_register(dev, &rk_rng->rng); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip hwrng\n"); > + > + return 0; > +} > + > +static int __maybe_unused rk_rng_runtime_suspend(struct device *dev) > +{ > + struct rk_rng *rk_rng = dev_get_drvdata(dev); > + > + rk_rng_cleanup(&rk_rng->rng); > + > + return 0; > +} > + > +static int __maybe_unused rk_rng_runtime_resume(struct device *dev) > +{ > + struct rk_rng *rk_rng = dev_get_drvdata(dev); > + > + return rk_rng_init(&rk_rng->rng); > +} > + > +static const struct dev_pm_ops rk_rng_pm_ops = { > + SET_RUNTIME_PM_OPS(rk_rng_runtime_suspend, > + rk_rng_runtime_resume, NULL) > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, > + pm_runtime_force_resume) > +}; > + > +static const struct of_device_id rk_rng_dt_match[] = { > + { .compatible = "rockchip,rk3568-rng", }, > + { /* sentinel */ }, > +}; > + > +MODULE_DEVICE_TABLE(of, rk_rng_dt_match); > + > +static struct platform_driver rk_rng_driver = { > + .driver = { > + .name = "rockchip-rng", > + .pm = &rk_rng_pm_ops, > + .of_match_table = rk_rng_dt_match, > + }, > + .probe = rk_rng_probe, > +}; > + > +module_platform_driver(rk_rng_driver); > + > +MODULE_DESCRIPTION("Rockchip RK3568 True Random Number Generator driver"); > +MODULE_AUTHOR("Lin Jinhan <troy.lin@rock-chips.com>"); > +MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); > +MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>"); > +MODULE_LICENSE("GPL"); > -- > 2.45.2
diff --git a/MAINTAINERS b/MAINTAINERS index 7b2b8b1f526c..2745cfe56774 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19698,6 +19698,7 @@ M: Daniel Golle <daniel@makrotopia.org> M: Aurelien Jarno <aurelien@aurel32.net> S: Maintained F: Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml +F: drivers/char/hw_random/rockchip-rng.c ROCKCHIP RASTER 2D GRAPHIC ACCELERATION UNIT DRIVER M: Jacob Chen <jacob-chen@iotwrt.com> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 442c40efb200..2b62cd08f91a 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -573,6 +573,20 @@ config HW_RANDOM_JH7110 To compile this driver as a module, choose M here. The module will be called jh7110-trng. +config HW_RANDOM_ROCKCHIP + tristate "Rockchip True Random Number Generator" + depends on HW_RANDOM && (ARCH_ROCKCHIP || COMPILE_TEST) + depends on HAS_IOMEM + default HW_RANDOM + help + This driver provides kernel-side support for the True Random Number + Generator hardware found on some Rockchip SoC like RK3566 or RK3568. + + To compile this driver as a module, choose M here: the + module will be called rockchip-rng. + + If unsure, say Y. + endif # HW_RANDOM config UML_RANDOM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 32549a1186dc..01f012eab440 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -48,4 +48,5 @@ obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o +obj-$(CONFIG_HW_RANDOM_ROCKCHIP) += rockchip-rng.o obj-$(CONFIG_HW_RANDOM_JH7110) += jh7110-trng.o diff --git a/drivers/char/hw_random/rockchip-rng.c b/drivers/char/hw_random/rockchip-rng.c new file mode 100644 index 000000000000..7e45e9880e3a --- /dev/null +++ b/drivers/char/hw_random/rockchip-rng.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * rockchip-rng.c True Random Number Generator driver for Rockchip RK3568 SoC + * + * Copyright (c) 2018, Fuzhou Rockchip Electronics Co., Ltd. + * Copyright (c) 2022, Aurelien Jarno + * Authors: + * Lin Jinhan <troy.lin@rock-chips.com> + * Aurelien Jarno <aurelien@aurel32.net> + */ +#include <linux/clk.h> +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> +#include <linux/slab.h> + +#define RK_RNG_AUTOSUSPEND_DELAY 100 +#define RK_RNG_MAX_BYTE 32 +#define RK_RNG_POLL_PERIOD_US 100 +#define RK_RNG_POLL_TIMEOUT_US 10000 + +/* + * TRNG collects osc ring output bit every RK_RNG_SAMPLE_CNT time. The value is + * a tradeoff between speed and quality and has been adjusted to get a quality + * of ~900 (~90% of FIPS 140-2 successes). + */ +#define RK_RNG_SAMPLE_CNT 1000 + +/* TRNG registers from RK3568 TRM-Part2, section 5.4.1 */ +#define TRNG_RST_CTL 0x0004 +#define TRNG_RNG_CTL 0x0400 +#define TRNG_RNG_CTL_LEN_64_BIT (0x00 << 4) +#define TRNG_RNG_CTL_LEN_128_BIT (0x01 << 4) +#define TRNG_RNG_CTL_LEN_192_BIT (0x02 << 4) +#define TRNG_RNG_CTL_LEN_256_BIT (0x03 << 4) +#define TRNG_RNG_CTL_OSC_RING_SPEED_0 (0x00 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_1 (0x01 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_2 (0x02 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_3 (0x03 << 2) +#define TRNG_RNG_CTL_ENABLE BIT(1) +#define TRNG_RNG_CTL_START BIT(0) +#define TRNG_RNG_SAMPLE_CNT 0x0404 +#define TRNG_RNG_DOUT 0x0410 + +struct rk_rng { + struct hwrng rng; + void __iomem *base; + struct reset_control *rst; + int clk_num; + struct clk_bulk_data *clk_bulks; +}; + +static int rk_rng_init(struct hwrng *rng) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + int ret; + + /* start clocks */ + ret = clk_bulk_prepare_enable(rk_rng->clk_num, rk_rng->clk_bulks); + if (ret < 0) { + dev_err((struct device *) rk_rng->rng.priv, + "Failed to enable clks %d\n", ret); + return ret; + } + + /* set the sample period */ + writel(RK_RNG_SAMPLE_CNT, rk_rng->base + TRNG_RNG_SAMPLE_CNT); + + /* set osc ring speed and enable it */ + writel(TRNG_RNG_CTL_LEN_256_BIT | + TRNG_RNG_CTL_OSC_RING_SPEED_0 | + TRNG_RNG_CTL_ENABLE, + rk_rng->base + TRNG_RNG_CTL); + + return 0; +} + +static void rk_rng_cleanup(struct hwrng *rng) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + + /* stop TRNG */ + writel(0, rk_rng->base + TRNG_RNG_CTL); + + /* stop clocks */ + clk_bulk_disable_unprepare(rk_rng->clk_num, rk_rng->clk_bulks); +} + +static int rk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + size_t to_read = min_t(size_t, max, RK_RNG_MAX_BYTE); + u32 reg; + int ret = 0; + + ret = pm_runtime_resume_and_get((struct device *) rk_rng->rng.priv); + if (ret < 0) + return ret; + + /* Start collecting random data */ + writel(TRNG_RNG_CTL_START, rk_rng->base + TRNG_RNG_CTL); + + ret = readl_poll_timeout(rk_rng->base + TRNG_RNG_CTL, reg, + !(reg & TRNG_RNG_CTL_START), + RK_RNG_POLL_PERIOD_US, + RK_RNG_POLL_TIMEOUT_US); + if (ret < 0) + goto out; + + /* Read random data stored in the registers */ + memcpy_fromio(buf, rk_rng->base + TRNG_RNG_DOUT, to_read); +out: + pm_runtime_mark_last_busy((struct device *) rk_rng->rng.priv); + pm_runtime_put_sync_autosuspend((struct device *) rk_rng->rng.priv); + + return (ret < 0) ? ret : to_read; +} + +static int rk_rng_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rk_rng *rk_rng; + int ret; + + rk_rng = devm_kzalloc(dev, sizeof(*rk_rng), GFP_KERNEL); + if (!rk_rng) + return -ENOMEM; + + rk_rng->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rk_rng->base)) + return PTR_ERR(rk_rng->base); + + rk_rng->clk_num = devm_clk_bulk_get_all(dev, &rk_rng->clk_bulks); + if (rk_rng->clk_num < 0) + return dev_err_probe(dev, rk_rng->clk_num, + "Failed to get clks property\n"); + + rk_rng->rst = devm_reset_control_array_get_exclusive(&pdev->dev); + if (IS_ERR(rk_rng->rst)) + return dev_err_probe(dev, PTR_ERR(rk_rng->rst), + "Failed to get reset property\n"); + + reset_control_assert(rk_rng->rst); + udelay(2); + reset_control_deassert(rk_rng->rst); + + platform_set_drvdata(pdev, rk_rng); + + rk_rng->rng.name = dev_driver_string(dev); + if (!IS_ENABLED(CONFIG_PM)) { + rk_rng->rng.init = rk_rng_init; + rk_rng->rng.cleanup = rk_rng_cleanup; + } + rk_rng->rng.read = rk_rng_read; + rk_rng->rng.priv = (unsigned long) dev; + rk_rng->rng.quality = 900; + + pm_runtime_set_autosuspend_delay(dev, RK_RNG_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(dev); + devm_pm_runtime_enable(dev); + + ret = devm_hwrng_register(dev, &rk_rng->rng); + if (ret) + return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip hwrng\n"); + + return 0; +} + +static int __maybe_unused rk_rng_runtime_suspend(struct device *dev) +{ + struct rk_rng *rk_rng = dev_get_drvdata(dev); + + rk_rng_cleanup(&rk_rng->rng); + + return 0; +} + +static int __maybe_unused rk_rng_runtime_resume(struct device *dev) +{ + struct rk_rng *rk_rng = dev_get_drvdata(dev); + + return rk_rng_init(&rk_rng->rng); +} + +static const struct dev_pm_ops rk_rng_pm_ops = { + SET_RUNTIME_PM_OPS(rk_rng_runtime_suspend, + rk_rng_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) +}; + +static const struct of_device_id rk_rng_dt_match[] = { + { .compatible = "rockchip,rk3568-rng", }, + { /* sentinel */ }, +}; + +MODULE_DEVICE_TABLE(of, rk_rng_dt_match); + +static struct platform_driver rk_rng_driver = { + .driver = { + .name = "rockchip-rng", + .pm = &rk_rng_pm_ops, + .of_match_table = rk_rng_dt_match, + }, + .probe = rk_rng_probe, +}; + +module_platform_driver(rk_rng_driver); + +MODULE_DESCRIPTION("Rockchip RK3568 True Random Number Generator driver"); +MODULE_AUTHOR("Lin Jinhan <troy.lin@rock-chips.com>"); +MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); +MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>"); +MODULE_LICENSE("GPL");