rockchip: only use HWRNG on RK3568 for now

Testing turned out that the HWRNG quality varies greatly on RK3566,
even on supposedly identical boards and SoC revisions.
Hence enable the HWRNG driver only on RK3568 for now.
Allow users to simply tune sample_count and quality to allow easily
testing results on different boards and SoCs.

Link: https://patchwork.kernel.org/project/linux-arm-kernel/cover/[email protected]/
Signed-off-by: Daniel Golle <[email protected]>

target/linux/rockchip/patches-6.6/300-hwrng-add-Rockchip-SoC-hwrng-driver.patch → target/linux/rockchip/patches-6.6/300-hwrng-add-hwrng-driver-for-Rockchip-RK3568-SoC.patch

@@ -1,56 +1,27 @@
-From patchwork Sat Nov 12 14:10:58 2022
-Content-Type: text/plain; charset="utf-8"
-MIME-Version: 1.0
-Content-Transfer-Encoding: 7bit
-X-Patchwork-Submitter: Aurelien Jarno <[email protected]>
-X-Patchwork-Id: 13041222
-Return-Path: 
- <linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org>
-X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
-	aws-us-west-2-korg-lkml-1.web.codeaurora.org
+From cea47ad1fbd46d3096fcf5c6905db3d12b5da960 Mon Sep 17 00:00:00 2001
 From: Aurelien Jarno <[email protected]>
-To: Olivia Mackall <[email protected]>,
-	Herbert Xu <[email protected]>,
-	Rob Herring <[email protected]>,
-	Krzysztof Kozlowski <[email protected]>,
-	Heiko Stuebner <[email protected]>,
-	Philipp Zabel <[email protected]>,
-	Lin Jinhan <[email protected]>
-Cc: [email protected] (open list:HARDWARE RANDOM NUMBER GENERATOR
- CORE),
-	[email protected] (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE
- BINDINGS),
-	[email protected] (moderated list:ARM/Rockchip SoC
- support),
-	[email protected] (open list:ARM/Rockchip SoC support),
-	[email protected] (open list),
-	Aurelien Jarno <[email protected]>
-Subject: [PATCH v1 2/3] hwrng: add Rockchip SoC hwrng driver
-Date: Sat, 12 Nov 2022 15:10:58 +0100
-Message-Id: <[email protected]>
-In-Reply-To: <[email protected]>
-References: <[email protected]>
-MIME-Version: 1.0
-List-Id: <linux-arm-kernel.lists.infradead.org>
+Date: Sun, 21 Jul 2024 01:48:04 +0100
+Subject: [PATCH 2/3] hwrng: add hwrng driver for Rockchip RK3568 SoC
 
 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
+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.
+rockchip,sample-count in DT, in a tradeoff between quality and speed.
 
 Signed-off-by: Aurelien Jarno <[email protected]>
+[[email protected]: code style fixes, add DT properties]
+Signed-off-by: Daniel Golle <[email protected]>
+Acked-by: Krzysztof Kozlowski <[email protected]>
 ---
  drivers/char/hw_random/Kconfig        |  14 ++
  drivers/char/hw_random/Makefile       |   1 +
- drivers/char/hw_random/rockchip-rng.c | 251 ++++++++++++++++++++++++++
- 3 files changed, 266 insertions(+)
+ drivers/char/hw_random/rockchip-rng.c | 230 ++++++++++++++++++++++++++
+ 4 files changed, 246 insertions(+)
  create mode 100644 drivers/char/hw_random/rockchip-rng.c
 
 --- a/drivers/char/hw_random/Kconfig
@@ -60,18 +31,18 @@ Signed-off-by: Aurelien Jarno <[email protected]>
  	  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.
++	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.
++	  To compile this driver as a module, choose M here: the
++	  module will be called rockchip-rng.
 +
-+          If unsure, say Y.
++	  If unsure, say Y.
 +
  endif # HW_RANDOM
  
@@ -86,10 +57,10 @@ Signed-off-by: Aurelien Jarno <[email protected]>
  obj-$(CONFIG_HW_RANDOM_JH7110) += jh7110-trng.o
 --- /dev/null
 +++ b/drivers/char/hw_random/rockchip-rng.c
-@@ -0,0 +1,251 @@
+@@ -0,0 +1,230 @@
 +// SPDX-License-Identifier: GPL-2.0
 +/*
-+ * rockchip-rng.c True Random Number Generator driver for Rockchip SoCs
++ * 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
@@ -103,7 +74,8 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +#include <linux/iopoll.h>
 +#include <linux/kernel.h>
 +#include <linux/module.h>
-+#include <linux/of_platform.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
 +#include <linux/pm_runtime.h>
 +#include <linux/reset.h>
 +#include <linux/slab.h>
@@ -113,13 +85,6 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +#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
@@ -131,17 +96,11 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +#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_0			0x0410
-+#define TRNG_RNG_DOUT_1			0x0414
-+#define TRNG_RNG_DOUT_2			0x0418
-+#define TRNG_RNG_DOUT_3			0x041c
-+#define TRNG_RNG_DOUT_4			0x0420
-+#define TRNG_RNG_DOUT_5			0x0424
-+#define TRNG_RNG_DOUT_6			0x0428
-+#define TRNG_RNG_DOUT_7			0x042c
++#define TRNG_RNG_DOUT			0x0410
 +
 +struct rk_rng {
 +	struct hwrng rng;
@@ -149,18 +108,18 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +	struct reset_control *rst;
 +	int clk_num;
 +	struct clk_bulk_data *clk_bulks;
++	u32 sample_cnt;
 +};
 +
-+/* The mask determine the bits that are updated */
++/* 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_relaxed((mask << 16) | val, rng->base + TRNG_RNG_CTL);
++	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);
-+	u32 reg;
 +	int ret;
 +
 +	/* start clocks */
@@ -172,13 +131,13 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +	}
 +
 +	/* set the sample period */
-+	writel(RK_RNG_SAMPLE_CNT, rk_rng->base + TRNG_RNG_SAMPLE_CNT);
++	writel(rk_rng->sample_cnt, rk_rng->base + TRNG_RNG_SAMPLE_CNT);
 +
 +	/* set osc ring speed and enable it */
-+	reg = TRNG_RNG_CTL_LEN_256_BIT |
-+		   TRNG_RNG_CTL_OSC_RING_SPEED_0 |
-+		   TRNG_RNG_CTL_ENABLE;
-+	rk_rng_write_ctl(rk_rng, reg, 0xffff);
++	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;
 +}
@@ -186,11 +145,9 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +static void rk_rng_cleanup(struct hwrng *rng)
 +{
 +	struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng);
-+	u32 reg;
 +
 +	/* stop TRNG */
-+	reg = 0;
-+	rk_rng_write_ctl(rk_rng, reg, 0xffff);
++	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);
@@ -199,15 +156,16 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +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;
-+	int i;
 +
-+	pm_runtime_get_sync((struct device *) rk_rng->rng.priv);
++	ret = pm_runtime_resume_and_get((struct device *) rk_rng->rng.priv);
++	if (ret < 0)
++		return ret;
 +
 +	/* Start collecting random data */
-+	reg = TRNG_RNG_CTL_START;
-+	rk_rng_write_ctl(rk_rng, reg, reg);
++	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),
@@ -216,27 +174,23 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +	if (ret < 0)
 +		goto out;
 +
-+	/* Read random data stored in big endian in the registers */
-+	ret = min_t(size_t, max, RK_RNG_MAX_BYTE);
-+	for (i = 0; i < ret; i += 4) {
-+		reg = readl_relaxed(rk_rng->base + TRNG_RNG_DOUT_0 + i);
-+		*(u32 *)(buf + i) = be32_to_cpu(reg);
-+	}
-+
++	/* 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;
++	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;
++	u32 quality;
 +	int ret;
 +
-+	rk_rng = devm_kzalloc(dev, sizeof(struct rk_rng), GFP_KERNEL);
++	rk_rng = devm_kzalloc(dev, sizeof(*rk_rng), GFP_KERNEL);
 +	if (!rk_rng)
 +		return -ENOMEM;
 +
@@ -249,11 +203,19 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +		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);
++	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");
 +
++	ret = of_property_read_u32(dev->of_node, "rockchip,sample-count", &rk_rng->sample_cnt);
++	if (ret)
++		return dev_err_probe(dev, ret, "Failed to get sample-count property\n");
++
++	ret = of_property_read_u32(dev->of_node, "quality", &quality);
++	if (ret || quality > 1024)
++		return dev_err_probe(dev, ret, "Failed to get quality property\n");
++
 +	reset_control_assert(rk_rng->rst);
 +	udelay(2);
 +	reset_control_deassert(rk_rng->rst);
@@ -261,36 +223,26 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +	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
++	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;
++	rk_rng->rng.quality = quality;
 +
 +	pm_runtime_set_autosuspend_delay(dev, RK_RNG_AUTOSUSPEND_DELAY);
 +	pm_runtime_use_autosuspend(dev);
-+	pm_runtime_enable(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");
 +
-+	dev_info(&pdev->dev, "Registered Rockchip hwrng\n");
-+
-+	return 0;
-+}
-+
-+static int rk_rng_remove(struct platform_device *pdev)
-+{
-+	pm_runtime_disable(&pdev->dev);
-+
 +	return 0;
 +}
 +
-+#ifdef CONFIG_PM
-+static int rk_rng_runtime_suspend(struct device *dev)
++static int __maybe_unused rk_rng_runtime_suspend(struct device *dev)
 +{
 +	struct rk_rng *rk_rng = dev_get_drvdata(dev);
 +
@@ -299,13 +251,12 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +	return 0;
 +}
 +
-+static int rk_rng_runtime_resume(struct device *dev)
++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);
 +}
-+#endif
 +
 +static const struct dev_pm_ops rk_rng_pm_ops = {
 +	SET_RUNTIME_PM_OPS(rk_rng_runtime_suspend,
@@ -315,10 +266,8 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +};
 +
 +static const struct of_device_id rk_rng_dt_match[] = {
-+	{
-+		.compatible = "rockchip,rk3568-rng",
-+	},
-+	{},
++	{ .compatible = "rockchip,rk3568-rng", },
++	{ /* sentinel */ },
 +};
 +
 +MODULE_DEVICE_TABLE(of, rk_rng_dt_match);
@@ -330,11 +279,12 @@ Signed-off-by: Aurelien Jarno <[email protected]>
 +		.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 <[email protected]>, Aurelien Jarno <[email protected]>");
-+MODULE_LICENSE("GPL v2");
++MODULE_DESCRIPTION("Rockchip RK3568 True Random Number Generator driver");
++MODULE_AUTHOR("Lin Jinhan <[email protected]>");
++MODULE_AUTHOR("Aurelien Jarno <[email protected]>");
++MODULE_AUTHOR("Daniel Golle <[email protected]>");
++MODULE_LICENSE("GPL");

target/linux/rockchip/patches-6.6/301-arm64-dts-rockchip-add-DT-entry-for-RNG-to-RK3568.patch

@@ -0,0 +1,49 @@
+From 756e7d3251ad8f6c72e7bf4c476537a89f673e38 Mon Sep 17 00:00:00 2001
+From: Aurelien Jarno <[email protected]>
+Date: Sun, 21 Jul 2024 01:48:38 +0100
+Subject: [PATCH 3/3] arm64: dts: rockchip: add DT entry for RNG to RK356x
+
+Enable the just added Rockchip RNG driver for RK356x SoCs.
+
+Signed-off-by: Aurelien Jarno <[email protected]>
+Signed-off-by: Daniel Golle <[email protected]>
+---
+ arch/arm64/boot/dts/rockchip/rk3568.dtsi |  7 +++++++
+ arch/arm64/boot/dts/rockchip/rk356x.dtsi | 10 ++++++++++
+ 2 files changed, 17 insertions(+)
+
+--- a/arch/arm64/boot/dts/rockchip/rk3568.dtsi
++++ b/arch/arm64/boot/dts/rockchip/rk3568.dtsi
+@@ -257,6 +257,13 @@
+ 	};
+ };
+ 
++&rng {
++	rockchip,sample-count = <1000>;
++	quality = <900>;
++
++	status = "okay";
++};
++
+ &usb_host0_xhci {
+ 	phys = <&usb2phy0_otg>, <&combphy0 PHY_TYPE_USB3>;
+ 	phy-names = "usb2-phy", "usb3-phy";
+--- a/arch/arm64/boot/dts/rockchip/rk356x.dtsi
++++ b/arch/arm64/boot/dts/rockchip/rk356x.dtsi
+@@ -1105,6 +1105,16 @@
+ 		status = "disabled";
+ 	};
+ 
++	rng: rng@fe388000 {
++		compatible = "rockchip,rk3568-rng";
++		reg = <0x0 0xfe388000 0x0 0x4000>;
++		clocks = <&cru CLK_TRNG_NS>, <&cru HCLK_TRNG_NS>;
++		clock-names = "core", "ahb";
++		resets = <&cru SRST_TRNG_NS>;
++		reset-names = "reset";
++		status = "disabled";
++	};
++
+ 	i2s0_8ch: i2s@fe400000 {
+ 		compatible = "rockchip,rk3568-i2s-tdm";
+ 		reg = <0x0 0xfe400000 0x0 0x1000>;

target/linux/rockchip/patches-6.6/301-arm64-dts-rockchip-add-DT-entry-for-RNG-to-RK356x.patch

@@ -1,56 +0,0 @@
-From patchwork Sat Nov 12 14:10:59 2022
-Content-Type: text/plain; charset="utf-8"
-MIME-Version: 1.0
-Content-Transfer-Encoding: 7bit
-X-Patchwork-Submitter: Aurelien Jarno <[email protected]>
-X-Patchwork-Id: 13041221
-From: Aurelien Jarno <[email protected]>
-To: Olivia Mackall <[email protected]>,
-	Herbert Xu <[email protected]>,
-	Rob Herring <[email protected]>,
-	Krzysztof Kozlowski <[email protected]>,
-	Heiko Stuebner <[email protected]>,
-	Philipp Zabel <[email protected]>,
-	Lin Jinhan <[email protected]>
-Cc: [email protected] (open list:HARDWARE RANDOM NUMBER GENERATOR
- CORE),
-	[email protected] (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE
- BINDINGS),
-	[email protected] (moderated list:ARM/Rockchip SoC
- support),
-	[email protected] (open list:ARM/Rockchip SoC support),
-	[email protected] (open list),
-	Aurelien Jarno <[email protected]>
-Subject: [PATCH v1 3/3] arm64: dts: rockchip: add DT entry for RNG to RK356x
-Date: Sat, 12 Nov 2022 15:10:59 +0100
-Message-Id: <[email protected]>
-In-Reply-To: <[email protected]>
-References: <[email protected]>
-MIME-Version: 1.0
-List-Id: <linux-arm-kernel.lists.infradead.org>
-
-Enable the just added Rockchip RNG driver for RK356x SoCs.
-
-Signed-off-by: Aurelien Jarno <[email protected]>
----
- arch/arm64/boot/dts/rockchip/rk356x.dtsi | 9 +++++++++
- 1 file changed, 9 insertions(+)
-
---- a/arch/arm64/boot/dts/rockchip/rk356x.dtsi
-+++ b/arch/arm64/boot/dts/rockchip/rk356x.dtsi
-@@ -1848,6 +1848,15 @@
- 		};
- 	};
- 
-+	rng: rng@fe388000 {
-+		compatible = "rockchip,rk3568-rng";
-+		reg = <0x0 0xfe388000 0x0 0x4000>;
-+		clocks = <&cru CLK_TRNG_NS>, <&cru HCLK_TRNG_NS>;
-+		clock-names = "trng_clk", "trng_hclk";
-+		resets = <&cru SRST_TRNG_NS>;
-+		reset-names = "reset";
-+	};
-+
- 	pinctrl: pinctrl {
- 		compatible = "rockchip,rk3568-pinctrl";
- 		rockchip,grf = <&grf>;