[PATCH v3 0/5] Add support for StarFive JH7110 TRNG driver

[PATCH v3 0/5] Add support for StarFive JH7110 TRNG driver

[Chanho Park]

This patchset adds to support StarFive JH7110 TRNG driver. Due to lack
of readl_relaxed API, the first patch tries to import the
APIs(read/write_relaxed) from Linux kernel's implementation. The second
patch adds the missing security clocks which are required by the trng
IP.

This IP can support 128-bit and 256-bit random number generation but
this patch makes 256-bit default mode for convenience.

Changes from v2:
- Patch #3: Add error handling codes of probe() which are suggested by Jaehoon

Changes from v1:
- Patch #3: Apply Heinrich's reviews and his codes
- Patch #5: Add Heinrich's R-b tag

Chanho Park (5):
  riscv: import read/write_relaxed functions
  clk: starfive: jh7110: Add security clocks
  rng: Add StarFive JH7110 RNG driver
  riscv: dts: jh7110: Add rng device tree node
  configs: visionfive2: Enable JH7110 RNG driver

 arch/riscv/dts/jh7110.dtsi             |  10 +
 arch/riscv/include/asm/io.h            |  45 ++++
 configs/starfive_visionfive2_defconfig |   2 +
 drivers/clk/starfive/clk-jh7110.c      |  10 +
 drivers/rng/Kconfig                    |   6 +
 drivers/rng/Makefile                   |   1 +
 drivers/rng/jh7110_rng.c               | 271 +++++++++++++++++++++++++
 7 files changed, 345 insertions(+)
 create mode 100644 drivers/rng/jh7110_rng.c

-- 
2.39.2

[PATCH v3 1/5] riscv: import read/write_relaxed functions

[Chanho Park]

This imports mmio functions from Linux's arch/riscv/include/asm/mmio.h
to use read/write[b|w|l|q]_relaxed functions.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 arch/riscv/include/asm/io.h | 45 +++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index b16e6dfa3760..4170877a1ae0 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -323,6 +323,51 @@ static inline void writesl(unsigned int *addr, const void *data, int longlen)
 #define insw_p(port, to, len)		insw(port, to, len)
 #define insl_p(port, to, len)		insl(port, to, len)
 
+/*
+ * Unordered I/O memory access primitives.  These are even more relaxed than
+ * the relaxed versions, as they don't even order accesses between successive
+ * operations to the I/O regions.
+ */
+#define readb_cpu(c)		({ u8  __r = __raw_readb(c); __r; })
+#define readw_cpu(c)		({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
+#define readl_cpu(c)		({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
+
+#define writeb_cpu(v, c)	((void)__raw_writeb((v), (c)))
+#define writew_cpu(v, c)	((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
+#define writel_cpu(v, c)	((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
+
+#ifdef CONFIG_64BIT
+#define readq_cpu(c)		({ u64 __r = le64_to_cpu((__force __le64)__raw_readq(c)); __r; })
+#define writeq_cpu(v, c)	((void)__raw_writeq((__force u64)cpu_to_le64(v), (c)))
+#endif
+
+/*
+ * Relaxed I/O memory access primitives. These follow the Device memory
+ * ordering rules but do not guarantee any ordering relative to Normal memory
+ * accesses.  These are defined to order the indicated access (either a read or
+ * write) with all other I/O memory accesses to the same peripheral. Since the
+ * platform specification defines that all I/O regions are strongly ordered on
+ * channel 0, no explicit fences are required to enforce this ordering.
+ */
+/* FIXME: These are now the same as asm-generic */
+#define __io_rbr()		do {} while (0)
+#define __io_rar()		do {} while (0)
+#define __io_rbw()		do {} while (0)
+#define __io_raw()		do {} while (0)
+
+#define readb_relaxed(c)	({ u8  __v; __io_rbr(); __v = readb_cpu(c); __io_rar(); __v; })
+#define readw_relaxed(c)	({ u16 __v; __io_rbr(); __v = readw_cpu(c); __io_rar(); __v; })
+#define readl_relaxed(c)	({ u32 __v; __io_rbr(); __v = readl_cpu(c); __io_rar(); __v; })
+
+#define writeb_relaxed(v, c)	({ __io_rbw(); writeb_cpu((v), (c)); __io_raw(); })
+#define writew_relaxed(v, c)	({ __io_rbw(); writew_cpu((v), (c)); __io_raw(); })
+#define writel_relaxed(v, c)	({ __io_rbw(); writel_cpu((v), (c)); __io_raw(); })
+
+#ifdef CONFIG_64BIT
+#define readq_relaxed(c)	({ u64 __v; __io_rbr(); __v = readq_cpu(c); __io_rar(); __v; })
+#define writeq_relaxed(v, c)	({ __io_rbw(); writeq_cpu((v), (c)); __io_raw(); })
+#endif
+
 #include <asm-generic/io.h>
 
 #endif	/* __ASM_RISCV_IO_H */
-- 
2.39.2

[PATCH v3 2/5] clk: starfive: jh7110: Add security clocks

[Chanho Park]

Add STGCLK_SEC_HCLK and STGCLK_SEC_MISCAHB clocks for JH7110 TRNG
device.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 drivers/clk/starfive/clk-jh7110.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/clk/starfive/clk-jh7110.c b/drivers/clk/starfive/clk-jh7110.c
index 31aaf3340f94..a835541e48e9 100644
--- a/drivers/clk/starfive/clk-jh7110.c
+++ b/drivers/clk/starfive/clk-jh7110.c
@@ -539,6 +539,16 @@ static int jh7110_stgcrg_init(struct udevice *dev)
 				 "pcie1_tl", "stg_axiahb",
 				 OFFSET(JH7110_STGCLK_PCIE1_TL)));
 
+	/* Security clocks */
+	clk_dm(JH7110_STG_ID_TRANS(JH7110_STGCLK_SEC_HCLK),
+	       starfive_clk_gate(priv->reg,
+				 "sec_ahb", "stg_axiahb",
+				 OFFSET(JH7110_STGCLK_SEC_HCLK)));
+	clk_dm(JH7110_STG_ID_TRANS(JH7110_STGCLK_SEC_MISCAHB),
+	       starfive_clk_gate(priv->reg,
+				 "sec_misc_ahb", "stg_axiahb",
+				 OFFSET(JH7110_STGCLK_SEC_MISCAHB)));
+
 	return 0;
 }
 
-- 
2.39.2

[PATCH v3 3/5] rng: Add StarFive JH7110 RNG driver

[Chanho Park]

Adds to support JH7110 TRNG driver which is based on linux kernel's
jh7110-trng.c. This can support to generate 256-bit random numbers and
128-bit but this makes 256-bit default for convenience.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 drivers/rng/Kconfig      |   6 +
 drivers/rng/Makefile     |   1 +
 drivers/rng/jh7110_rng.c | 271 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 278 insertions(+)
 create mode 100644 drivers/rng/jh7110_rng.c

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 994cc35b2744..0dba1e06b429 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -91,4 +91,10 @@ config TPM_RNG
 	  functionality. Enable random number generator on TPM
 	  devices.
 
+config RNG_JH7110
+	bool "StarFive JH7110 Random Number Generator support"
+	depends on DM_RNG && STARFIVE_JH7110
+	help
+	  Enable True Random Number Generator in StarFive JH7110 SoCs.
+
 endif
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 47b323e61ee3..9de762c8a1c3 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o
 obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o
 obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o
 obj-$(CONFIG_TPM_RNG) += tpm_rng.o
+obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o
diff --git a/drivers/rng/jh7110_rng.c b/drivers/rng/jh7110_rng.c
new file mode 100644
index 000000000000..075a2d78eb2c
--- /dev/null
+++ b/drivers/rng/jh7110_rng.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TRNG driver for the StarFive JH7110 SoC
+ *
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <reset.h>
+#include <rng.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+
+/* trng register offset */
+#define STARFIVE_CTRL			0x00
+#define STARFIVE_STAT			0x04
+#define STARFIVE_MODE			0x08
+#define STARFIVE_SMODE			0x0C
+#define STARFIVE_IE			0x10
+#define STARFIVE_ISTAT			0x14
+#define STARFIVE_RAND0			0x20
+#define STARFIVE_RAND1			0x24
+#define STARFIVE_RAND2			0x28
+#define STARFIVE_RAND3			0x2C
+#define STARFIVE_RAND4			0x30
+#define STARFIVE_RAND5			0x34
+#define STARFIVE_RAND6			0x38
+#define STARFIVE_RAND7			0x3C
+#define STARFIVE_AUTO_RQSTS		0x60
+#define STARFIVE_AUTO_AGE		0x64
+
+/* CTRL CMD */
+#define STARFIVE_CTRL_EXEC_NOP		0x0
+#define STARFIVE_CTRL_GENE_RANDNUM	0x1
+#define STARFIVE_CTRL_EXEC_RANDRESEED	0x2
+
+/* STAT */
+#define STARFIVE_STAT_NONCE_MODE	BIT(2)
+#define STARFIVE_STAT_R256		BIT(3)
+#define STARFIVE_STAT_MISSION_MODE	BIT(8)
+#define STARFIVE_STAT_SEEDED		BIT(9)
+#define STARFIVE_STAT_LAST_RESEED(x)	((x) << 16)
+#define STARFIVE_STAT_SRVC_RQST		BIT(27)
+#define STARFIVE_STAT_RAND_GENERATING	BIT(30)
+#define STARFIVE_STAT_RAND_SEEDING	BIT(31)
+#define STARFIVE_STAT_RUNNING		(STARFIVE_STAT_RAND_GENERATING | \
+					 STARFIVE_STAT_RAND_SEEDING)
+
+/* MODE */
+#define STARFIVE_MODE_R256		BIT(3)
+
+/* SMODE */
+#define STARFIVE_SMODE_NONCE_MODE	BIT(2)
+#define STARFIVE_SMODE_MISSION_MODE	BIT(8)
+#define STARFIVE_SMODE_MAX_REJECTS(x)	((x) << 16)
+
+/* IE */
+#define STARFIVE_IE_RAND_RDY_EN		BIT(0)
+#define STARFIVE_IE_SEED_DONE_EN	BIT(1)
+#define STARFIVE_IE_LFSR_LOCKUP_EN	BIT(4)
+#define STARFIVE_IE_GLBL_EN		BIT(31)
+
+#define STARFIVE_IE_ALL			(STARFIVE_IE_GLBL_EN | \
+					 STARFIVE_IE_RAND_RDY_EN | \
+					 STARFIVE_IE_SEED_DONE_EN | \
+					 STARFIVE_IE_LFSR_LOCKUP_EN)
+
+/* ISTAT */
+#define STARFIVE_ISTAT_RAND_RDY		BIT(0)
+#define STARFIVE_ISTAT_SEED_DONE	BIT(1)
+#define STARFIVE_ISTAT_LFSR_LOCKUP	BIT(4)
+
+#define STARFIVE_RAND_LEN		sizeof(u32)
+
+enum mode {
+	PRNG_128BIT,
+	PRNG_256BIT,
+};
+
+struct starfive_trng_plat {
+	void *base;
+	struct clk *hclk;
+	struct clk *ahb;
+	struct reset_ctl *rst;
+	u32 mode;
+};
+
+static inline int starfive_trng_wait_idle(struct starfive_trng_plat *trng)
+{
+	u32 stat;
+
+	return readl_relaxed_poll_timeout(trng->base + STARFIVE_STAT, stat,
+					  !(stat & STARFIVE_STAT_RUNNING),
+					  100000);
+}
+
+static inline void starfive_trng_irq_mask_clear(struct starfive_trng_plat *trng)
+{
+	/* clear register: ISTAT */
+	u32 data = readl(trng->base + STARFIVE_ISTAT);
+
+	writel(data, trng->base + STARFIVE_ISTAT);
+}
+
+static int starfive_trng_cmd(struct starfive_trng_plat *trng, u32 cmd)
+{
+	u32 stat, flg;
+	int ret;
+
+	switch (cmd) {
+	case STARFIVE_CTRL_GENE_RANDNUM:
+		writel(cmd, trng->base + STARFIVE_CTRL);
+		flg = STARFIVE_ISTAT_RAND_RDY;
+		break;
+	case STARFIVE_CTRL_EXEC_RANDRESEED:
+		writel(cmd, trng->base + STARFIVE_CTRL);
+		flg = STARFIVE_ISTAT_SEED_DONE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = readl_relaxed_poll_timeout(trng->base + STARFIVE_ISTAT, stat,
+					 (stat & flg), 1000);
+	writel(flg, trng->base + STARFIVE_ISTAT);
+
+	return ret;
+}
+
+static int starfive_trng_read(struct udevice *dev, void *data, size_t len)
+{
+	struct starfive_trng_plat *trng = dev_get_plat(dev);
+	u8 *buffer = data;
+	int iter_mask;
+
+	if (trng->mode == PRNG_256BIT)
+		iter_mask = 7;
+	else
+		iter_mask = 3;
+
+	for (int i = 0; len; ++i, i &= iter_mask) {
+		u32 val;
+		size_t step;
+		int ret;
+
+		ret = starfive_trng_cmd(trng, STARFIVE_CTRL_GENE_RANDNUM);
+		if (ret)
+			return ret;
+
+		val = readl(trng->base + STARFIVE_RAND0 +
+			    (i * STARFIVE_RAND_LEN));
+		step = min_t(size_t, len, STARFIVE_RAND_LEN);
+		memcpy(buffer, &val, step);
+		buffer += step;
+		len -= step;
+	}
+
+	return 0;
+}
+
+static int starfive_trng_init(struct starfive_trng_plat *trng)
+{
+	u32 mode, intr = 0;
+
+	/* setup Auto Request/Age register */
+	writel(0, trng->base + STARFIVE_AUTO_AGE);
+	writel(0, trng->base + STARFIVE_AUTO_RQSTS);
+
+	/* clear register: ISTAT */
+	starfive_trng_irq_mask_clear(trng);
+
+	intr |= STARFIVE_IE_ALL;
+	writel(intr, trng->base + STARFIVE_IE);
+
+	mode = readl(trng->base + STARFIVE_MODE);
+
+	switch (trng->mode) {
+	case PRNG_128BIT:
+		mode &= ~STARFIVE_MODE_R256;
+		break;
+	case PRNG_256BIT:
+		mode |= STARFIVE_MODE_R256;
+		break;
+	default:
+		mode |= STARFIVE_MODE_R256;
+		break;
+	}
+
+	writel(mode, trng->base + STARFIVE_MODE);
+
+	return starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
+}
+
+static int starfive_trng_probe(struct udevice *dev)
+{
+	struct starfive_trng_plat *pdata = dev_get_plat(dev);
+	int err;
+
+	err = clk_enable(pdata->hclk);
+	if (err)
+		return err;
+
+	err = clk_enable(pdata->ahb);
+	if (err)
+		goto err_ahb;
+
+	err = reset_deassert(pdata->rst);
+	if (err)
+		goto err_reset;
+
+	pdata->mode = PRNG_256BIT;
+
+	err = starfive_trng_init(pdata);
+	if (err)
+		goto err_trng_init;
+
+	return 0;
+
+err_trng_init:
+	reset_assert(pdata->rst);
+err_reset:
+	clk_disable(pdata->ahb);
+err_ahb:
+	clk_disable(pdata->hclk);
+
+	return err;
+}
+
+static int starfive_trng_of_to_plat(struct udevice *dev)
+{
+	struct starfive_trng_plat *pdata = dev_get_plat(dev);
+
+	pdata->base = (void *)dev_read_addr(dev);
+	if (!pdata->base)
+		return -ENODEV;
+
+	pdata->hclk = devm_clk_get(dev, "hclk");
+	if (IS_ERR(pdata->hclk))
+		return -ENODEV;
+
+	pdata->ahb = devm_clk_get(dev, "ahb");
+	if (IS_ERR(pdata->ahb))
+		return -ENODEV;
+
+	pdata->rst = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(pdata->rst))
+		return -ENODEV;
+
+	return 0;
+}
+
+static const struct dm_rng_ops starfive_trng_ops = {
+	.read = starfive_trng_read,
+};
+
+static const struct udevice_id starfive_trng_match[] = {
+	{
+		.compatible = "starfive,jh7110-trng",
+	},
+	{},
+};
+
+U_BOOT_DRIVER(starfive_trng) = {
+	.name = "jh7110-trng",
+	.id = UCLASS_RNG,
+	.of_match = starfive_trng_match,
+	.probe = starfive_trng_probe,
+	.ops = &starfive_trng_ops,
+	.plat_auto = sizeof(struct starfive_trng_plat),
+	.of_to_plat = starfive_trng_of_to_plat,
+};
-- 
2.39.2

[PATCH v3 4/5] riscv: dts: jh7110: Add rng device tree node

[Chanho Park]

Adds jh7110 trng device tree node.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 arch/riscv/dts/jh7110.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/riscv/dts/jh7110.dtsi b/arch/riscv/dts/jh7110.dtsi
index ec237a46ffba..13c47f7caa36 100644
--- a/arch/riscv/dts/jh7110.dtsi
+++ b/arch/riscv/dts/jh7110.dtsi
@@ -627,6 +627,16 @@
 			status = "disabled";
 		};
 
+		rng: rng@1600c000 {
+			compatible = "starfive,jh7110-trng";
+			reg = <0x0 0x1600C000 0x0 0x4000>;
+			clocks = <&stgcrg JH7110_STGCLK_SEC_HCLK>,
+				 <&stgcrg JH7110_STGCLK_SEC_MISCAHB>;
+			clock-names = "hclk", "ahb";
+			resets = <&stgcrg JH7110_STGRST_SEC_TOP_HRESETN>;
+			interrupts = <30>;
+		};
+
 		aoncrg: clock-controller@17000000 {
 			compatible = "starfive,jh7110-aoncrg";
 			reg = <0x0 0x17000000 0x0 0x10000>;
-- 
2.39.2

[PATCH v3 5/5] configs: visionfive2: Enable JH7110 RNG driver

[Chanho Park]

Enables JH7110 RNG driver to visionfive2 board.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
 configs/starfive_visionfive2_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/configs/starfive_visionfive2_defconfig b/configs/starfive_visionfive2_defconfig
index b21754feafce..b15e7d24db19 100644
--- a/configs/starfive_visionfive2_defconfig
+++ b/configs/starfive_visionfive2_defconfig
@@ -120,6 +120,8 @@ CONFIG_SPL_PINCTRL_STARFIVE=y
 CONFIG_SPL_PINCTRL_STARFIVE_JH7110=y
 CONFIG_PINCTRL_STARFIVE=y
 # CONFIG_RAM_SIFIVE is not set
+CONFIG_DM_RNG=y
+CONFIG_RNG_JH7110=y
 CONFIG_SYS_NS16550=y
 CONFIG_CADENCE_QSPI=y
 CONFIG_TIMER_EARLY=y
-- 
2.39.2

Re: [PATCH v3 3/5] rng: Add StarFive JH7110 RNG driver

[Heinrich Schuchardt]

On 11/1/23 13:40, Chanho Park wrote:
> Adds to support JH7110 TRNG driver which is based on linux kernel's
> jh7110-trng.c. This can support to generate 256-bit random numbers and
> 128-bit but this makes 256-bit default for convenience.
>
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
>   drivers/rng/Kconfig      |   6 +
>   drivers/rng/Makefile     |   1 +
>   drivers/rng/jh7110_rng.c | 271 +++++++++++++++++++++++++++++++++++++++
>   3 files changed, 278 insertions(+)
>   create mode 100644 drivers/rng/jh7110_rng.c
>
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
> index 994cc35b2744..0dba1e06b429 100644
> --- a/drivers/rng/Kconfig
> +++ b/drivers/rng/Kconfig
> @@ -91,4 +91,10 @@ config TPM_RNG
>   	  functionality. Enable random number generator on TPM
>   	  devices.
>
> +config RNG_JH7110
> +	bool "StarFive JH7110 Random Number Generator support"
> +	depends on DM_RNG && STARFIVE_JH7110
> +	help
> +	  Enable True Random Number Generator in StarFive JH7110 SoCs.
> +
>   endif
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
> index 47b323e61ee3..9de762c8a1c3 100644
> --- a/drivers/rng/Makefile
> +++ b/drivers/rng/Makefile
> @@ -15,3 +15,4 @@ obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o
>   obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o
>   obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o
>   obj-$(CONFIG_TPM_RNG) += tpm_rng.o
> +obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o
> diff --git a/drivers/rng/jh7110_rng.c b/drivers/rng/jh7110_rng.c
> new file mode 100644
> index 000000000000..075a2d78eb2c
> --- /dev/null
> +++ b/drivers/rng/jh7110_rng.c
> @@ -0,0 +1,271 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * TRNG driver for the StarFive JH7110 SoC
> + *
> + */
> +
> +#include <clk.h>
> +#include <dm.h>
> +#include <reset.h>
> +#include <rng.h>
> +#include <asm/io.h>
> +#include <linux/iopoll.h>
> +
> +/* trng register offset */
> +#define STARFIVE_CTRL			0x00
> +#define STARFIVE_STAT			0x04
> +#define STARFIVE_MODE			0x08
> +#define STARFIVE_SMODE			0x0C
> +#define STARFIVE_IE			0x10
> +#define STARFIVE_ISTAT			0x14
> +#define STARFIVE_RAND0			0x20
> +#define STARFIVE_RAND1			0x24
> +#define STARFIVE_RAND2			0x28
> +#define STARFIVE_RAND3			0x2C
> +#define STARFIVE_RAND4			0x30
> +#define STARFIVE_RAND5			0x34
> +#define STARFIVE_RAND6			0x38
> +#define STARFIVE_RAND7			0x3C
> +#define STARFIVE_AUTO_RQSTS		0x60
> +#define STARFIVE_AUTO_AGE		0x64
> +
> +/* CTRL CMD */
> +#define STARFIVE_CTRL_EXEC_NOP		0x0
> +#define STARFIVE_CTRL_GENE_RANDNUM	0x1
> +#define STARFIVE_CTRL_EXEC_RANDRESEED	0x2
> +
> +/* STAT */
> +#define STARFIVE_STAT_NONCE_MODE	BIT(2)
> +#define STARFIVE_STAT_R256		BIT(3)
> +#define STARFIVE_STAT_MISSION_MODE	BIT(8)
> +#define STARFIVE_STAT_SEEDED		BIT(9)
> +#define STARFIVE_STAT_LAST_RESEED(x)	((x) << 16)
> +#define STARFIVE_STAT_SRVC_RQST		BIT(27)
> +#define STARFIVE_STAT_RAND_GENERATING	BIT(30)
> +#define STARFIVE_STAT_RAND_SEEDING	BIT(31)
> +#define STARFIVE_STAT_RUNNING		(STARFIVE_STAT_RAND_GENERATING | \
> +					 STARFIVE_STAT_RAND_SEEDING)
> +
> +/* MODE */
> +#define STARFIVE_MODE_R256		BIT(3)
> +
> +/* SMODE */
> +#define STARFIVE_SMODE_NONCE_MODE	BIT(2)
> +#define STARFIVE_SMODE_MISSION_MODE	BIT(8)
> +#define STARFIVE_SMODE_MAX_REJECTS(x)	((x) << 16)
> +
> +/* IE */
> +#define STARFIVE_IE_RAND_RDY_EN		BIT(0)
> +#define STARFIVE_IE_SEED_DONE_EN	BIT(1)
> +#define STARFIVE_IE_LFSR_LOCKUP_EN	BIT(4)
> +#define STARFIVE_IE_GLBL_EN		BIT(31)
> +
> +#define STARFIVE_IE_ALL			(STARFIVE_IE_GLBL_EN | \
> +					 STARFIVE_IE_RAND_RDY_EN | \
> +					 STARFIVE_IE_SEED_DONE_EN | \
> +					 STARFIVE_IE_LFSR_LOCKUP_EN)
> +
> +/* ISTAT */
> +#define STARFIVE_ISTAT_RAND_RDY		BIT(0)
> +#define STARFIVE_ISTAT_SEED_DONE	BIT(1)
> +#define STARFIVE_ISTAT_LFSR_LOCKUP	BIT(4)
> +
> +#define STARFIVE_RAND_LEN		sizeof(u32)
> +
> +enum mode {
> +	PRNG_128BIT,
> +	PRNG_256BIT,
> +};
> +
> +struct starfive_trng_plat {
> +	void *base;
> +	struct clk *hclk;
> +	struct clk *ahb;
> +	struct reset_ctl *rst;
> +	u32 mode;
> +};
> +
> +static inline int starfive_trng_wait_idle(struct starfive_trng_plat *trng)
> +{
> +	u32 stat;
> +
> +	return readl_relaxed_poll_timeout(trng->base + STARFIVE_STAT, stat,
> +					  !(stat & STARFIVE_STAT_RUNNING),
> +					  100000);
> +}
> +
> +static inline void starfive_trng_irq_mask_clear(struct starfive_trng_plat *trng)
> +{
> +	/* clear register: ISTAT */
> +	u32 data = readl(trng->base + STARFIVE_ISTAT);
> +
> +	writel(data, trng->base + STARFIVE_ISTAT);
> +}
> +
> +static int starfive_trng_cmd(struct starfive_trng_plat *trng, u32 cmd)
> +{
> +	u32 stat, flg;
> +	int ret;
> +
> +	switch (cmd) {
> +	case STARFIVE_CTRL_GENE_RANDNUM:
> +		writel(cmd, trng->base + STARFIVE_CTRL);
> +		flg = STARFIVE_ISTAT_RAND_RDY;
> +		break;
> +	case STARFIVE_CTRL_EXEC_RANDRESEED:
> +		writel(cmd, trng->base + STARFIVE_CTRL);
> +		flg = STARFIVE_ISTAT_SEED_DONE;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	ret = readl_relaxed_poll_timeout(trng->base + STARFIVE_ISTAT, stat,
> +					 (stat & flg), 1000);
> +	writel(flg, trng->base + STARFIVE_ISTAT);
> +
> +	return ret;
> +}
> +
> +static int starfive_trng_read(struct udevice *dev, void *data, size_t len)
> +{
> +	struct starfive_trng_plat *trng = dev_get_plat(dev);
> +	u8 *buffer = data;
> +	int iter_mask;
> +
> +	if (trng->mode == PRNG_256BIT)
> +		iter_mask = 7;
> +	else
> +		iter_mask = 3;
> +
> +	for (int i = 0; len; ++i, i &= iter_mask) {
> +		u32 val;
> +		size_t step;
> +		int ret;
> +

I think you are missing

    if (!i) {

here as one call to starfive_trng_cmd is giving you 128 or 256 bits of
entropy.

> +		ret = starfive_trng_cmd(trng, STARFIVE_CTRL_GENE_RANDNUM);

}

Best regards

Heinrich

> +		if (ret)
> +			return ret;
> +
> +		val = readl(trng->base + STARFIVE_RAND0 +
> +			    (i * STARFIVE_RAND_LEN));
> +		step = min_t(size_t, len, STARFIVE_RAND_LEN);
> +		memcpy(buffer, &val, step);
> +		buffer += step;
> +		len -= step;
> +	}
> +
> +	return 0;
> +}
> +
> +static int starfive_trng_init(struct starfive_trng_plat *trng)
> +{
> +	u32 mode, intr = 0;
> +
> +	/* setup Auto Request/Age register */
> +	writel(0, trng->base + STARFIVE_AUTO_AGE);
> +	writel(0, trng->base + STARFIVE_AUTO_RQSTS);
> +
> +	/* clear register: ISTAT */
> +	starfive_trng_irq_mask_clear(trng);
> +
> +	intr |= STARFIVE_IE_ALL;
> +	writel(intr, trng->base + STARFIVE_IE);
> +
> +	mode = readl(trng->base + STARFIVE_MODE);
> +
> +	switch (trng->mode) {
> +	case PRNG_128BIT:
> +		mode &= ~STARFIVE_MODE_R256;
> +		break;
> +	case PRNG_256BIT:
> +		mode |= STARFIVE_MODE_R256;
> +		break;
> +	default:
> +		mode |= STARFIVE_MODE_R256;
> +		break;
> +	}
> +
> +	writel(mode, trng->base + STARFIVE_MODE);
> +
> +	return starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
> +}
> +
> +static int starfive_trng_probe(struct udevice *dev)
> +{
> +	struct starfive_trng_plat *pdata = dev_get_plat(dev);
> +	int err;
> +
> +	err = clk_enable(pdata->hclk);
> +	if (err)
> +		return err;
> +
> +	err = clk_enable(pdata->ahb);
> +	if (err)
> +		goto err_ahb;
> +
> +	err = reset_deassert(pdata->rst);
> +	if (err)
> +		goto err_reset;
> +
> +	pdata->mode = PRNG_256BIT;
> +
> +	err = starfive_trng_init(pdata);
> +	if (err)
> +		goto err_trng_init;
> +
> +	return 0;
> +
> +err_trng_init:
> +	reset_assert(pdata->rst);
> +err_reset:
> +	clk_disable(pdata->ahb);
> +err_ahb:
> +	clk_disable(pdata->hclk);
> +
> +	return err;
> +}
> +
> +static int starfive_trng_of_to_plat(struct udevice *dev)
> +{
> +	struct starfive_trng_plat *pdata = dev_get_plat(dev);
> +
> +	pdata->base = (void *)dev_read_addr(dev);
> +	if (!pdata->base)
> +		return -ENODEV;
> +
> +	pdata->hclk = devm_clk_get(dev, "hclk");
> +	if (IS_ERR(pdata->hclk))
> +		return -ENODEV;
> +
> +	pdata->ahb = devm_clk_get(dev, "ahb");
> +	if (IS_ERR(pdata->ahb))
> +		return -ENODEV;
> +
> +	pdata->rst = devm_reset_control_get(dev, NULL);
> +	if (IS_ERR(pdata->rst))
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +
> +static const struct dm_rng_ops starfive_trng_ops = {
> +	.read = starfive_trng_read,
> +};
> +
> +static const struct udevice_id starfive_trng_match[] = {
> +	{
> +		.compatible = "starfive,jh7110-trng",
> +	},
> +	{},
> +};
> +
> +U_BOOT_DRIVER(starfive_trng) = {
> +	.name = "jh7110-trng",
> +	.id = UCLASS_RNG,
> +	.of_match = starfive_trng_match,
> +	.probe = starfive_trng_probe,
> +	.ops = &starfive_trng_ops,
> +	.plat_auto = sizeof(struct starfive_trng_plat),
> +	.of_to_plat = starfive_trng_of_to_plat,
> +};

RE: [PATCH v3 3/5] rng: Add StarFive JH7110 RNG driver

[Chanho Park]

Hi,

> -----Original Message-----
> From: Heinrich Schuchardt <xypron.glpk@gmx.de>
> Sent: Wednesday, November 1, 2023 9:00 PM
> To: Chanho Park <chanho61.park@samsung.com>
> Cc: Sughosh Ganu <sughosh.ganu@linaro.org>; u-boot@lists.denx.de; Rick
> Chen <rick@andestech.com>; Leo <ycliang@andestech.com>; Jaehoon Chung
> <jh80.chung@samsung.com>
> Subject: Re: [PATCH v3 3/5] rng: Add StarFive JH7110 RNG driver
> 
> On 11/1/23 13:40, Chanho Park wrote:
> > Adds to support JH7110 TRNG driver which is based on linux kernel's
> > jh7110-trng.c. This can support to generate 256-bit random numbers and
> > 128-bit but this makes 256-bit default for convenience.
> >
> > Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> > ---
> >   drivers/rng/Kconfig      |   6 +
> >   drivers/rng/Makefile     |   1 +
> >   drivers/rng/jh7110_rng.c | 271 +++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 278 insertions(+)
> >   create mode 100644 drivers/rng/jh7110_rng.c
> >
> > diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
> > index 994cc35b2744..0dba1e06b429 100644
> > --- a/drivers/rng/Kconfig
> > +++ b/drivers/rng/Kconfig
> > @@ -91,4 +91,10 @@ config TPM_RNG
> >   	  functionality. Enable random number generator on TPM
> >   	  devices.
> >
> > +config RNG_JH7110
> > +	bool "StarFive JH7110 Random Number Generator support"
> > +	depends on DM_RNG && STARFIVE_JH7110
> > +	help
> > +	  Enable True Random Number Generator in StarFive JH7110 SoCs.
> > +
> >   endif
> > diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
> > index 47b323e61ee3..9de762c8a1c3 100644
> > --- a/drivers/rng/Makefile
> > +++ b/drivers/rng/Makefile
> > @@ -15,3 +15,4 @@ obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o
> >   obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o
> >   obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o
> >   obj-$(CONFIG_TPM_RNG) += tpm_rng.o
> > +obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o
> > diff --git a/drivers/rng/jh7110_rng.c b/drivers/rng/jh7110_rng.c
> > new file mode 100644
> > index 000000000000..075a2d78eb2c
> > --- /dev/null
> > +++ b/drivers/rng/jh7110_rng.c
> > @@ -0,0 +1,271 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * TRNG driver for the StarFive JH7110 SoC
> > + *
> > + */
> > +
> > +#include <clk.h>
> > +#include <dm.h>
> > +#include <reset.h>
> > +#include <rng.h>
> > +#include <asm/io.h>
> > +#include <linux/iopoll.h>
> > +
> > +/* trng register offset */
> > +#define STARFIVE_CTRL			0x00
> > +#define STARFIVE_STAT			0x04
> > +#define STARFIVE_MODE			0x08
> > +#define STARFIVE_SMODE			0x0C
> > +#define STARFIVE_IE			0x10
> > +#define STARFIVE_ISTAT			0x14
> > +#define STARFIVE_RAND0			0x20
> > +#define STARFIVE_RAND1			0x24
> > +#define STARFIVE_RAND2			0x28
> > +#define STARFIVE_RAND3			0x2C
> > +#define STARFIVE_RAND4			0x30
> > +#define STARFIVE_RAND5			0x34
> > +#define STARFIVE_RAND6			0x38
> > +#define STARFIVE_RAND7			0x3C
> > +#define STARFIVE_AUTO_RQSTS		0x60
> > +#define STARFIVE_AUTO_AGE		0x64
> > +
> > +/* CTRL CMD */
> > +#define STARFIVE_CTRL_EXEC_NOP		0x0
> > +#define STARFIVE_CTRL_GENE_RANDNUM	0x1
> > +#define STARFIVE_CTRL_EXEC_RANDRESEED	0x2
> > +
> > +/* STAT */
> > +#define STARFIVE_STAT_NONCE_MODE	BIT(2)
> > +#define STARFIVE_STAT_R256		BIT(3)
> > +#define STARFIVE_STAT_MISSION_MODE	BIT(8)
> > +#define STARFIVE_STAT_SEEDED		BIT(9)
> > +#define STARFIVE_STAT_LAST_RESEED(x)	((x) << 16)
> > +#define STARFIVE_STAT_SRVC_RQST		BIT(27)
> > +#define STARFIVE_STAT_RAND_GENERATING	BIT(30)
> > +#define STARFIVE_STAT_RAND_SEEDING	BIT(31)
> > +#define STARFIVE_STAT_RUNNING		(STARFIVE_STAT_RAND_GENERATING | \
> > +					 STARFIVE_STAT_RAND_SEEDING)
> > +
> > +/* MODE */
> > +#define STARFIVE_MODE_R256		BIT(3)
> > +
> > +/* SMODE */
> > +#define STARFIVE_SMODE_NONCE_MODE	BIT(2)
> > +#define STARFIVE_SMODE_MISSION_MODE	BIT(8)
> > +#define STARFIVE_SMODE_MAX_REJECTS(x)	((x) << 16)
> > +
> > +/* IE */
> > +#define STARFIVE_IE_RAND_RDY_EN		BIT(0)
> > +#define STARFIVE_IE_SEED_DONE_EN	BIT(1)
> > +#define STARFIVE_IE_LFSR_LOCKUP_EN	BIT(4)
> > +#define STARFIVE_IE_GLBL_EN		BIT(31)
> > +
> > +#define STARFIVE_IE_ALL			(STARFIVE_IE_GLBL_EN | \
> > +					 STARFIVE_IE_RAND_RDY_EN | \
> > +					 STARFIVE_IE_SEED_DONE_EN | \
> > +					 STARFIVE_IE_LFSR_LOCKUP_EN)
> > +
> > +/* ISTAT */
> > +#define STARFIVE_ISTAT_RAND_RDY		BIT(0)
> > +#define STARFIVE_ISTAT_SEED_DONE	BIT(1)
> > +#define STARFIVE_ISTAT_LFSR_LOCKUP	BIT(4)
> > +
> > +#define STARFIVE_RAND_LEN		sizeof(u32)
> > +
> > +enum mode {
> > +	PRNG_128BIT,
> > +	PRNG_256BIT,
> > +};
> > +
> > +struct starfive_trng_plat {
> > +	void *base;
> > +	struct clk *hclk;
> > +	struct clk *ahb;
> > +	struct reset_ctl *rst;
> > +	u32 mode;
> > +};
> > +
> > +static inline int starfive_trng_wait_idle(struct starfive_trng_plat
> *trng)
> > +{
> > +	u32 stat;
> > +
> > +	return readl_relaxed_poll_timeout(trng->base + STARFIVE_STAT, stat,
> > +					  !(stat & STARFIVE_STAT_RUNNING),
> > +					  100000);
> > +}
> > +
> > +static inline void starfive_trng_irq_mask_clear(struct
> starfive_trng_plat *trng)
> > +{
> > +	/* clear register: ISTAT */
> > +	u32 data = readl(trng->base + STARFIVE_ISTAT);
> > +
> > +	writel(data, trng->base + STARFIVE_ISTAT);
> > +}
> > +
> > +static int starfive_trng_cmd(struct starfive_trng_plat *trng, u32 cmd)
> > +{
> > +	u32 stat, flg;
> > +	int ret;
> > +
> > +	switch (cmd) {
> > +	case STARFIVE_CTRL_GENE_RANDNUM:
> > +		writel(cmd, trng->base + STARFIVE_CTRL);
> > +		flg = STARFIVE_ISTAT_RAND_RDY;
> > +		break;
> > +	case STARFIVE_CTRL_EXEC_RANDRESEED:
> > +		writel(cmd, trng->base + STARFIVE_CTRL);
> > +		flg = STARFIVE_ISTAT_SEED_DONE;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	ret = readl_relaxed_poll_timeout(trng->base + STARFIVE_ISTAT, stat,
> > +					 (stat & flg), 1000);
> > +	writel(flg, trng->base + STARFIVE_ISTAT);
> > +
> > +	return ret;
> > +}
> > +
> > +static int starfive_trng_read(struct udevice *dev, void *data, size_t
> len)
> > +{
> > +	struct starfive_trng_plat *trng = dev_get_plat(dev);
> > +	u8 *buffer = data;
> > +	int iter_mask;
> > +
> > +	if (trng->mode == PRNG_256BIT)
> > +		iter_mask = 7;
> > +	else
> > +		iter_mask = 3;
> > +
> > +	for (int i = 0; len; ++i, i &= iter_mask) {
> > +		u32 val;
> > +		size_t step;
> > +		int ret;
> > +
> 
> I think you are missing
> 
>     if (!i) {
> 
> here as one call to starfive_trng_cmd is giving you 128 or 256 bits of
> entropy.
> 
> > +		ret = starfive_trng_cmd(trng, STARFIVE_CTRL_GENE_RANDNUM);
> 
> }

Oh. I missed this while I made the patches. Thanks for the heads up.
I'll quickly update it in the next patch.

Best Regards,
Chanho Park