On Fri, Jun 21, 2024 at 9:25 AM Daniel Golle <daniel@xxxxxxxxxxxxxx> wrote: > > From: Aurelien Jarno <aurelien@xxxxxxxxxxx> > > 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 RK356x 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@xxxxxxxxxxx> > [daniel@xxxxxxxxxxxxx: code style fixes] > Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx> > --- > MAINTAINERS | 1 + > drivers/char/hw_random/Kconfig | 14 ++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/rockchip-rng.c | 229 ++++++++++++++++++++++++++ > 4 files changed, 245 insertions(+) > create mode 100644 drivers/char/hw_random/rockchip-rng.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 77d449c89bf2..299b8c1a5fb5 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -19493,6 +19493,7 @@ M: Daniel Golle <daniel@xxxxxxxxxxxxxx> > M: Aurelien Jarno <aurelien@xxxxxxxxxxx> > 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@xxxxxxxxxx> > 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..6070abb73847 > --- /dev/null > +++ b/drivers/char/hw_random/rockchip-rng.c > @@ -0,0 +1,229 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * rockchip-rng.c True Random Number Generator driver for Rockchip SoCs > + * > + * Copyright (c) 2018, Fuzhou Rockchip Electronics Co., Ltd. > + * Copyright (c) 2022, Aurelien Jarno > + * Authors: > + * Lin Jinhan <troy.lin@xxxxxxxxxxxxxx> > + * Aurelien Jarno <aurelien@xxxxxxxxxxx> > + */ > +#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_platform.h> Need to explicitly include linux/platform_device.h for |struct platform_device| and devm_platform_iomap_resource(). > +#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_relaxed(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_relaxed(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_get_sync((struct device *) rk_rng->rng.priv); > + if (ret < 0) > + goto out; > + > + /* Start collecting random data */ > + writel_relaxed(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 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(&pdev->dev, false, false); > + 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); > +#ifndef CONFIG_PM > + rk_rng->rng.init = rk_rng_init; > + rk_rng->rng.cleanup = rk_rng_cleanup; > +#endif > + 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); > + pm_runtime_enable(dev); You can use devm_pm_runtime_enable(dev) here and simply get rid of the remove function, and also no explicit cleanup needed. > + > + ret = devm_hwrng_register(dev, &rk_rng->rng); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip hwrng\n"); This is missing cleanup for pm_runtime_enable(). > + > + dev_info(&pdev->dev, "Registered Rockchip hwrng\n"); > + > + return 0; > +} > + > +static int rk_rng_remove(struct platform_device *pdev) Return type of remove callback has been changed to void. This needs to be updated. ChenYu > +{ > + pm_runtime_disable(&pdev->dev); > + > + return 0; > +} > + > +#ifdef CONFIG_PM > +static int 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 rk_rng_runtime_resume(struct device *dev) > +{ > + struct rk_rng *rk_rng = dev_get_drvdata(dev); > + > + return rk_rng_init(&rk_rng->rng); > +} > +#endif > + > +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, > + .remove = rk_rng_remove, > +}; > + > +module_platform_driver(rk_rng_driver); > + > +MODULE_DESCRIPTION("Rockchip True Random Number Generator driver"); > +MODULE_AUTHOR("Lin Jinhan <troy.lin@xxxxxxxxxxxxxx>, Aurelien Jarno <aurelien@xxxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > -- > 2.45.2 >