@@ -19727,6 +19727,7 @@ 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>
@@ -572,6 +572,20 @@ 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
@@ -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
new file mode 100644
@@ -0,0 +1,227 @@
+// 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 (~87.5% 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_MASK GENMASK(15, 0)
+#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;
+};
+
+/* The mask in the upper 16 bits determines the bits that are updated */
+static void rk_rng_write_ctl(struct rk_rng *rng, u32 val, u32 mask)
+{
+ writel((mask << 16) | val, rng->base + TRNG_RNG_CTL);
+}
+
+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 */
+ rk_rng_write_ctl(rk_rng, TRNG_RNG_CTL_LEN_256_BIT |
+ TRNG_RNG_CTL_OSC_RING_SPEED_0 |
+ TRNG_RNG_CTL_ENABLE,
+ TRNG_RNG_CTL_MASK);
+
+ return 0;
+}
+
+static void rk_rng_cleanup(struct hwrng *rng)
+{
+ struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng);
+
+ /* stop TRNG */
+ rk_rng_write_ctl(rk_rng, 0, TRNG_RNG_CTL_MASK);
+
+ /* 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 */
+ rk_rng_write_ctl(rk_rng, TRNG_RNG_CTL_START, TRNG_RNG_CTL_START);
+
+ 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");