[PATCH v3 0/8] Add a random number generator uclass

[PATCH v3 0/8] Add a random number generator uclass

[Sughosh Ganu]

Add a random number generator(rng) uclass to facilitate adding drivers
for rng devices. I plan to add an implementation of the
EFI_RNG_PROTOCOL, which would get the random number from the rng
uclass -- the protocol would be used by the efi stub for getting a
random number for the kaslr feature.

The patch series also adds a driver for the rng device found on the
stm32mp1 and qemu platforms. A dummy rng driver for sandbox has also
been added, along with the unit test for the rng uclass.

Changes since V2:
* Add a driver for the virtio-rng device on qemu platform

Changes since V1:
* Add a SPDX header in rng.h
* Change the UCLASS_DRIVER name from hwrng to rng, consistent with the
  rest of the naming convention
* Handle review comment from Patrice Chotard


Sughosh Ganu (8):
  dm: rng: Add random number generator(rng) uclass
  clk: stm32mp1: Add a clock entry for RNG1 device
  stm32mp1: rng: Add a driver for random number generator(rng) device
  configs: stm32mp15: Enable random number generator(rng) device
  sandbox: rng: Add a random number generator(rng) driver
  configs: sandbox: Enable random number generator(rng) device
  test: rng: Add basic test for random number generator(rng) uclass
  virtio: rng: Add a random number generator(rng) driver

 arch/sandbox/dts/test.dts           |   4 +
 configs/sandbox64_defconfig         |   2 +
 configs/sandbox_defconfig           |   2 +
 configs/stm32mp15_basic_defconfig   |   2 +
 configs/stm32mp15_optee_defconfig   |   2 +
 configs/stm32mp15_trusted_defconfig |   2 +
 drivers/Kconfig                     |   2 +
 drivers/Makefile                    |   1 +
 drivers/clk/clk_stm32mp1.c          |   1 +
 drivers/rng/Kconfig                 |  21 +++++
 drivers/rng/Makefile                |   8 ++
 drivers/rng/rng-uclass.c            |  23 ++++++
 drivers/rng/sandbox_rng.c           |  36 ++++++++
 drivers/rng/stm32mp1_rng.c          | 158 ++++++++++++++++++++++++++++++++++++
 drivers/virtio/Kconfig              |   6 ++
 drivers/virtio/Makefile             |   1 +
 drivers/virtio/virtio-uclass.c      |   1 +
 drivers/virtio/virtio_rng.c         |  72 ++++++++++++++++
 include/dm/uclass-id.h              |   1 +
 include/rng.h                       |  30 +++++++
 include/virtio.h                    |   4 +-
 test/dm/Makefile                    |   1 +
 test/dm/rng.c                       |  26 ++++++
 23 files changed, 405 insertions(+), 1 deletion(-)
 create mode 100644 drivers/rng/Kconfig
 create mode 100644 drivers/rng/Makefile
 create mode 100644 drivers/rng/rng-uclass.c
 create mode 100644 drivers/rng/sandbox_rng.c
 create mode 100644 drivers/rng/stm32mp1_rng.c
 create mode 100644 drivers/virtio/virtio_rng.c
 create mode 100644 include/rng.h
 create mode 100644 test/dm/rng.c

-- 
2.7.4

[PATCH v3 1/8] dm: rng: Add random number generator(rng) uclass

[Sughosh Ganu]

Add a uclass for reading a random number seed from a random number
generator device.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 drivers/Kconfig          |  2 ++
 drivers/Makefile         |  1 +
 drivers/rng/Kconfig      |  7 +++++++
 drivers/rng/Makefile     |  6 ++++++
 drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
 include/dm/uclass-id.h   |  1 +
 include/rng.h            | 30 ++++++++++++++++++++++++++++++
 7 files changed, 70 insertions(+)
 create mode 100644 drivers/rng/Kconfig
 create mode 100644 drivers/rng/Makefile
 create mode 100644 drivers/rng/rng-uclass.c
 create mode 100644 include/rng.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 9d99ce0..e34a227 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
 
 source "drivers/reset/Kconfig"
 
+source "drivers/rng/Kconfig"
+
 source "drivers/rtc/Kconfig"
 
 source "drivers/scsi/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index e977f19..6c619b1 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
 
 obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
 obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
+obj-$(CONFIG_DM_RNG) += rng/
 endif
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
new file mode 100644
index 0000000..dd44cc0
--- /dev/null
+++ b/drivers/rng/Kconfig
@@ -0,0 +1,7 @@
+config DM_RNG
+	bool "Driver support for Random Number Generator devices"
+	depends on DM
+	help
+	  Enable driver model for random number generator(rng) devices.
+	  This interface is used to initialise the rng device and to
+	  read the random seed from the device.
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
new file mode 100644
index 0000000..311705b
--- /dev/null
+++ b/drivers/rng/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2019, Linaro Limited
+#
+
+obj-$(CONFIG_DM_RNG) += rng-uclass.o
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c
new file mode 100644
index 0000000..b6af3b8
--- /dev/null
+++ b/drivers/rng/rng-uclass.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+
+int dm_rng_read(struct udevice *dev, void *buffer, size_t size)
+{
+	const struct dm_rng_ops *ops = device_get_ops(dev);
+
+	if (!ops->read)
+		return -ENOSYS;
+
+	return ops->read(dev, buffer, size);
+}
+
+UCLASS_DRIVER(rng) = {
+	.name = "rng",
+	.id = UCLASS_RNG,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 0c563d8..192202d 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -86,6 +86,7 @@ enum uclass_id {
 	UCLASS_REGULATOR,	/* Regulator device */
 	UCLASS_REMOTEPROC,	/* Remote Processor device */
 	UCLASS_RESET,		/* Reset controller device */
+	UCLASS_RNG,		/* Random Number Generator */
 	UCLASS_RTC,		/* Real time clock device */
 	UCLASS_SCSI,		/* SCSI device */
 	UCLASS_SERIAL,		/* Serial UART */
diff --git a/include/rng.h b/include/rng.h
new file mode 100644
index 0000000..61d5da9
--- /dev/null
+++ b/include/rng.h
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#if !defined _RNG_H_
+#define _RNG_H_
+
+#include <dm.h>
+
+/**
+ * dm_rng_read() - read a random number seed from the rng device
+ * @buffer:	input buffer to put the read random seed into
+ * @size:	number of bytes of random seed read
+ *
+ */
+int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+
+/* struct dm_rng_ops - Operations for the hwrng uclass */
+struct dm_rng_ops {
+	/**
+	 * @read() - read a random number seed
+	 *
+	 * @data:	input buffer to read the random seed
+	 * @max:	total number of bytes to read
+	 */
+	int (*read)(struct udevice *dev, void *data, size_t max);
+};
+
+#endif /* _RNG_H_ */
-- 
2.7.4

[PATCH v3 2/8] clk: stm32mp1: Add a clock entry for RNG1 device

[Sughosh Ganu]

Add an entry for allowing clock enablement for the random number
generator peripheral, RNG1.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 drivers/clk/clk_stm32mp1.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c
index 3718970..da66bde 100644
--- a/drivers/clk/clk_stm32mp1.c
+++ b/drivers/clk/clk_stm32mp1.c
@@ -563,6 +563,7 @@ static const struct stm32mp1_clk_gate stm32mp1_clk_gate[] = {
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB4ENSETR, 10, GPIOK, _UNKNOWN_SEL),
 
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB5ENSETR, 0, GPIOZ, _UNKNOWN_SEL),
+	STM32MP1_CLK_SET_CLR(RCC_MP_AHB5ENSETR, 6, RNG1_K, _UNKNOWN_SEL),
 
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB6ENSETR, 7, ETHCK_K, _ETH_SEL),
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB6ENSETR, 8, ETHTX, _UNKNOWN_SEL),
-- 
2.7.4

[PATCH v3 3/8] stm32mp1: rng: Add a driver for random number generator(rng) device

[Sughosh Ganu]

Add a driver for the rng device found on stm32mp1 platforms. The
driver provides a routine for reading the random number seed from the
hardware device.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 drivers/rng/Kconfig        |   7 ++
 drivers/rng/Makefile       |   1 +
 drivers/rng/stm32mp1_rng.c | 158 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 166 insertions(+)
 create mode 100644 drivers/rng/stm32mp1_rng.c

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index dd44cc0..5fc11db 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -5,3 +5,10 @@ config DM_RNG
 	  Enable driver model for random number generator(rng) devices.
 	  This interface is used to initialise the rng device and to
 	  read the random seed from the device.
+
+config RNG_STM32MP1
+       bool "Enable random number generator for STM32MP1"
+       depends on ARCH_STM32MP && DM_RNG
+       default n
+       help
+         Enable STM32MP1 rng driver.
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 311705b..699beb3 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_DM_RNG) += rng-uclass.o
+obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
diff --git a/drivers/rng/stm32mp1_rng.c b/drivers/rng/stm32mp1_rng.c
new file mode 100644
index 0000000..5cd736d
--- /dev/null
+++ b/drivers/rng/stm32mp1_rng.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <reset.h>
+#include <rng.h>
+
+#include <asm/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+
+#define RNG_CR 0x00
+#define RNG_CR_RNGEN BIT(2)
+#define RNG_CR_CED BIT(5)
+
+#define RNG_SR 0x04
+#define RNG_SR_SEIS BIT(6)
+#define RNG_SR_CEIS BIT(5)
+#define RNG_SR_SECS BIT(2)
+#define RNG_SR_DRDY BIT(0)
+
+#define RNG_DR 0x08
+
+struct stm32_rng_platdata {
+	fdt_addr_t base;
+	struct clk clk;
+	struct reset_ctl rst;
+};
+
+static int stm32_rng_read(struct udevice *dev, void *data, size_t len)
+{
+	int retval = 0, i;
+	u32 sr, count, reg;
+	size_t increment;
+	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
+
+	while (len > 0) {
+		retval = readl_poll_timeout(pdata->base + RNG_SR, sr,
+					    sr & RNG_SR_DRDY, 10000);
+		if (retval)
+			return retval;
+
+		if (sr & (RNG_SR_SEIS | RNG_SR_SECS)) {
+			/* As per SoC TRM */
+			clrbits_le32(pdata->base + RNG_SR, RNG_SR_SEIS);
+			for (i = 0; i < 12; i++)
+				readl(pdata->base + RNG_DR);
+			if (readl(pdata->base + RNG_SR) & RNG_SR_SEIS) {
+				printf("RNG Noise");
+				return -EIO;
+			}
+			/* start again */
+			continue;
+		}
+
+		count = 4;
+		while (len && count) {
+			reg = readl(pdata->base + RNG_DR);
+			memcpy(data, &reg, min(len, sizeof(u32)));
+			increment = min(len, sizeof(u32));
+			data += increment;
+			retval += increment;
+			len -= increment;
+			count--;
+		}
+	}
+
+	return retval;
+}
+
+static int stm32_rng_init(struct stm32_rng_platdata *pdata)
+{
+	int err;
+
+	err = clk_enable(&pdata->clk);
+	if (err)
+		return err;
+
+	/* Disable CED */
+	writel(RNG_CR_RNGEN | RNG_CR_CED, pdata->base + RNG_CR);
+
+	/* clear error indicators */
+	writel(0, pdata->base + RNG_SR);
+
+	return 0;
+}
+
+static int stm32_rng_cleanup(struct stm32_rng_platdata *pdata)
+{
+
+	writel(0, pdata->base + RNG_CR);
+
+	return clk_disable(&pdata->clk);
+}
+
+static int stm32_rng_probe(struct udevice *dev)
+{
+	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
+
+	reset_assert(&pdata->rst);
+	udelay(20);
+	reset_deassert(&pdata->rst);
+
+	return stm32_rng_init(pdata);
+}
+
+static int stm32_rng_remove(struct udevice *dev)
+{
+	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
+
+	return stm32_rng_cleanup(pdata);
+}
+
+static int stm32_rng_ofdata_to_platdata(struct udevice *dev)
+{
+	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
+	int err;
+
+	pdata->base = dev_read_addr(dev);
+	if (!pdata->base)
+		return -ENOMEM;
+
+	err = clk_get_by_index(dev, 0, &pdata->clk);
+	if (err)
+		return err;
+
+	err = reset_get_by_index(dev, 0, &pdata->rst);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static const struct dm_rng_ops stm32_rng_ops = {
+	.read = stm32_rng_read,
+};
+
+static const struct udevice_id stm32_rng_match[] = {
+	{
+		.compatible = "st,stm32-rng",
+	},
+	{},
+};
+
+U_BOOT_DRIVER(stm32_rng) = {
+	.name = "stm32-rng",
+	.id = UCLASS_RNG,
+	.of_match = stm32_rng_match,
+	.ops = &stm32_rng_ops,
+	.probe = stm32_rng_probe,
+	.remove = stm32_rng_remove,
+	.platdata_auto_alloc_size = sizeof(struct stm32_rng_platdata),
+	.ofdata_to_platdata = stm32_rng_ofdata_to_platdata,
+};
-- 
2.7.4

[PATCH v3 4/8] configs: stm32mp15: Enable random number generator(rng) device

[Sughosh Ganu]

Enable support for the rng device on the stm32mp15 configs.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 configs/stm32mp15_basic_defconfig   | 2 ++
 configs/stm32mp15_optee_defconfig   | 2 ++
 configs/stm32mp15_trusted_defconfig | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index 358c2cd..5ca40e0 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -143,3 +143,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
diff --git a/configs/stm32mp15_optee_defconfig b/configs/stm32mp15_optee_defconfig
index a065d3e..b161cd1 100644
--- a/configs/stm32mp15_optee_defconfig
+++ b/configs/stm32mp15_optee_defconfig
@@ -127,3 +127,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index 632f11f..ddf244d 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -126,3 +126,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
-- 
2.7.4

[PATCH v3 5/8] sandbox: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

Add a sandbox driver for random number generation. Mostly aimed at
providing a unit test for rng uclass.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 arch/sandbox/dts/test.dts |  4 ++++
 drivers/rng/Kconfig       |  7 +++++++
 drivers/rng/Makefile      |  1 +
 drivers/rng/sandbox_rng.c | 36 ++++++++++++++++++++++++++++++++++++
 4 files changed, 48 insertions(+)
 create mode 100644 drivers/rng/sandbox_rng.c

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index fdb08f2..2c85540 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -599,6 +599,10 @@
 		reset-names = "other", "test";
 	};
 
+	rng at 0 {
+		compatible = "sandbox,sandbox-rng";
+	};
+
 	rproc_1: rproc at 1 {
 		compatible = "sandbox,test-processor";
 		remoteproc-name = "remoteproc-test-dev1";
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 5fc11db..3a1d3f0 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -6,6 +6,13 @@ config DM_RNG
 	  This interface is used to initialise the rng device and to
 	  read the random seed from the device.
 
+config RNG_SANDBOX
+       bool "Sandbox random number generator"
+       depends on SANDBOX && DM_RNG
+       help
+         Enable random number generator for sandbox. This is an
+	 emulation of a rng device.
+
 config RNG_STM32MP1
        bool "Enable random number generator for STM32MP1"
        depends on ARCH_STM32MP && DM_RNG
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 699beb3..3517005 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -4,4 +4,5 @@
 #
 
 obj-$(CONFIG_DM_RNG) += rng-uclass.o
+obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o
 obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
diff --git a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c
new file mode 100644
index 0000000..c5be552
--- /dev/null
+++ b/drivers/rng/sandbox_rng.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+
+static unsigned long random = 0xdeadbeef;
+
+static int sandbox_rng_read(struct udevice *dev, void *data, size_t len)
+{
+	random ^= ~0UL;
+	*(unsigned long *)data = random;
+
+	return sizeof(random);
+}
+
+static const struct dm_rng_ops sandbox_rng_ops = {
+	.read = sandbox_rng_read,
+};
+
+static const struct udevice_id sandbox_rng_match[] = {
+	{
+		.compatible = "sandbox,sandbox-rng",
+	},
+	{},
+};
+
+U_BOOT_DRIVER(sandbox_rng) = {
+	.name = "sandbox-rng",
+	.id = UCLASS_RNG,
+	.of_match = sandbox_rng_match,
+	.ops = &sandbox_rng_ops,
+};
-- 
2.7.4

[PATCH v3 6/8] configs: sandbox: Enable random number generator(rng) device

[Sughosh Ganu]

Enable support for random number generator on sandbox configs. This is
aimed primarily at adding unit test support for rng uclass.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 configs/sandbox64_defconfig | 2 ++
 configs/sandbox_defconfig   | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index cc536ff..a21d832 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -158,6 +158,8 @@ CONFIG_REGULATOR_RK8XX=y
 CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_SANDBOX=y
 CONFIG_DM_PWM=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 64245f7..9bdc0f5 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -179,6 +179,8 @@ CONFIG_REGULATOR_RK8XX=y
 CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_SANDBOX=y
 CONFIG_DM_PWM=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
-- 
2.7.4

[PATCH v3 7/8] test: rng: Add basic test for random number generator(rng) uclass

[Sughosh Ganu]

Add a unit test for testing the rng uclass functionality using the
sandbox rng driver.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 test/dm/Makefile |  1 +
 test/dm/rng.c    | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 test/dm/rng.c

diff --git a/test/dm/Makefile b/test/dm/Makefile
index 0c2fd5c..f61bf65 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -65,4 +65,5 @@ obj-$(CONFIG_VIRTIO_SANDBOX) += virtio.o
 obj-$(CONFIG_DMA) += dma.o
 obj-$(CONFIG_DM_MDIO) += mdio.o
 obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o
+obj-$(CONFIG_DM_RNG) += rng.o
 endif
diff --git a/test/dm/rng.c b/test/dm/rng.c
new file mode 100644
index 0000000..879e80a
--- /dev/null
+++ b/test/dm/rng.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+#include <dm/test.h>
+#include <test/ut.h>
+
+/* Basic test of the rng uclass */
+static int dm_test_rng_read(struct unit_test_state *uts)
+{
+	unsigned long val1 = 0, val2 = 0;
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device(UCLASS_RNG, 0, &dev));
+	ut_assertnonnull(dev);
+	dm_rng_read(dev, &val1, sizeof(val1));
+	dm_rng_read(dev, &val2, sizeof(val2));
+	ut_assert(val1 != val2);
+
+	return 0;
+}
+DM_TEST(dm_test_rng_read, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
-- 
2.7.4

[PATCH v3 8/8] virtio: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

Add a driver for the virtio-rng device on the qemu platform. The
device uses pci as a transport medium. The driver can be enabled with
the following configs

CONFIG_VIRTIO
CONFIG_DM_RNG
CONFIG_VIRTIO_PCI
CONFIG_VIRTIO_RNG

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
---

 drivers/virtio/Kconfig         |  6 ++++
 drivers/virtio/Makefile        |  1 +
 drivers/virtio/virtio-uclass.c |  1 +
 drivers/virtio/virtio_rng.c    | 72 ++++++++++++++++++++++++++++++++++++++++++
 include/virtio.h               |  4 ++-
 5 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 drivers/virtio/virtio_rng.c

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index a9d5fd0..2e3dd3b 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -59,4 +59,10 @@ config VIRTIO_BLK
 	  This is the virtual block driver for virtio. It can be used with
 	  QEMU based targets.
 
+config VIRTIO_RNG
+       bool "virtio rng driver"
+       depends on VIRTIO
+       help
+         This is the virtual random number generator driver. It can be used
+	 with Qemu based targets.
 endmenu
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 4579044..dc88809 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o
 obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o
 obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
 obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
+obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o
diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c
index 34397d7..436faa4 100644
--- a/drivers/virtio/virtio-uclass.c
+++ b/drivers/virtio/virtio-uclass.c
@@ -24,6 +24,7 @@
 static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
 	[VIRTIO_ID_NET]		= VIRTIO_NET_DRV_NAME,
 	[VIRTIO_ID_BLOCK]	= VIRTIO_BLK_DRV_NAME,
+	[VIRTIO_ID_RNG]		= VIRTIO_RNG_DRV_NAME,
 };
 
 int virtio_get_config(struct udevice *vdev, unsigned int offset,
diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c
new file mode 100644
index 0000000..19a0cc1
--- /dev/null
+++ b/drivers/virtio/virtio_rng.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+#include <virtio_types.h>
+#include <virtio.h>
+#include <virtio_ring.h>
+
+struct virtio_rng_priv {
+	struct virtqueue *rng_vq;
+};
+
+static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
+{
+	struct virtio_sg sg = { data, len };
+	struct virtio_sg *sgs[] = { &sg };
+	struct virtio_rng_priv *priv = dev_get_priv(dev);
+	unsigned int rsize;
+	int ret;
+
+	ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);
+	if (ret)
+		return ret;
+
+	virtqueue_kick(priv->rng_vq);
+
+	while (!virtqueue_get_buf(priv->rng_vq, &rsize))
+		;
+
+	return rsize;
+}
+
+static int virtio_rng_bind(struct udevice *dev)
+{
+	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
+
+	/* Indicate what driver features we support */
+	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
+
+	return 0;
+}
+
+static int virtio_rng_probe(struct udevice *dev)
+{
+	struct virtio_rng_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = virtio_find_vqs(dev, 1, &priv->rng_vq);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static const struct dm_rng_ops virtio_rng_ops = {
+	.read	= virtio_rng_read,
+};
+
+U_BOOT_DRIVER(virtio_rng) = {
+	.name	= VIRTIO_RNG_DRV_NAME,
+	.id	= UCLASS_RNG,
+	.bind	= virtio_rng_bind,
+	.probe	= virtio_rng_probe,
+	.remove = virtio_reset,
+	.ops	= &virtio_rng_ops,
+	.priv_auto_alloc_size = sizeof(struct virtio_rng_priv),
+	.flags	= DM_FLAG_ACTIVE_DMA,
+};
diff --git a/include/virtio.h b/include/virtio.h
index 654fdf1..561dcc3 100644
--- a/include/virtio.h
+++ b/include/virtio.h
@@ -22,10 +22,12 @@
 
 #define VIRTIO_ID_NET		1 /* virtio net */
 #define VIRTIO_ID_BLOCK		2 /* virtio block */
-#define VIRTIO_ID_MAX_NUM	3
+#define VIRTIO_ID_RNG		4 /* virtio rng */
+#define VIRTIO_ID_MAX_NUM	5
 
 #define VIRTIO_NET_DRV_NAME	"virtio-net"
 #define VIRTIO_BLK_DRV_NAME	"virtio-blk"
+#define VIRTIO_RNG_DRV_NAME	"virtio-rng"
 
 /* Status byte for guest to report progress, and synchronize features */
 
-- 
2.7.4

[PATCH v3 8/8] virtio: rng: Add a random number generator(rng) driver

[Ilias Apalodimas]

On Fri, Dec 13, 2019 at 12:44:27PM +0530, Sughosh Ganu wrote:
> Add a driver for the virtio-rng device on the qemu platform. The
> device uses pci as a transport medium. The driver can be enabled with
> the following configs
> 
> CONFIG_VIRTIO
> CONFIG_DM_RNG
> CONFIG_VIRTIO_PCI
> CONFIG_VIRTIO_RNG
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
> 
>  drivers/virtio/Kconfig         |  6 ++++
>  drivers/virtio/Makefile        |  1 +
>  drivers/virtio/virtio-uclass.c |  1 +
>  drivers/virtio/virtio_rng.c    | 72 ++++++++++++++++++++++++++++++++++++++++++
>  include/virtio.h               |  4 ++-
>  5 files changed, 83 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/virtio/virtio_rng.c
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index a9d5fd0..2e3dd3b 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -59,4 +59,10 @@ config VIRTIO_BLK
>  	  This is the virtual block driver for virtio. It can be used with
>  	  QEMU based targets.
>  
> +config VIRTIO_RNG
> +       bool "virtio rng driver"
> +       depends on VIRTIO
> +       help
> +         This is the virtual random number generator driver. It can be used
> +	 with Qemu based targets.
>  endmenu
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> index 4579044..dc88809 100644
> --- a/drivers/virtio/Makefile
> +++ b/drivers/virtio/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o
>  obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o
>  obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
>  obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
> +obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o
> diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c
> index 34397d7..436faa4 100644
> --- a/drivers/virtio/virtio-uclass.c
> +++ b/drivers/virtio/virtio-uclass.c
> @@ -24,6 +24,7 @@
>  static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
>  	[VIRTIO_ID_NET]		= VIRTIO_NET_DRV_NAME,
>  	[VIRTIO_ID_BLOCK]	= VIRTIO_BLK_DRV_NAME,
> +	[VIRTIO_ID_RNG]		= VIRTIO_RNG_DRV_NAME,
>  };
>  
>  int virtio_get_config(struct udevice *vdev, unsigned int offset,
> diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c
> new file mode 100644
> index 0000000..19a0cc1
> --- /dev/null
> +++ b/drivers/virtio/virtio_rng.c
> @@ -0,0 +1,72 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +#include <virtio_types.h>
> +#include <virtio.h>
> +#include <virtio_ring.h>
> +
> +struct virtio_rng_priv {
> +	struct virtqueue *rng_vq;
> +};
> +
> +static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
> +{
> +	struct virtio_sg sg = { data, len };
> +	struct virtio_sg *sgs[] = { &sg };
> +	struct virtio_rng_priv *priv = dev_get_priv(dev);
> +	unsigned int rsize;
> +	int ret;
> +
> +	ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);
> +	if (ret)
> +		return ret;
> +
> +	virtqueue_kick(priv->rng_vq);
> +
> +	while (!virtqueue_get_buf(priv->rng_vq, &rsize))
> +		;
> +
> +	return rsize;
> +}
> +
> +static int virtio_rng_bind(struct udevice *dev)
> +{
> +	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
> +
> +	/* Indicate what driver features we support */
> +	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
> +
> +	return 0;
> +}
> +
> +static int virtio_rng_probe(struct udevice *dev)
> +{
> +	struct virtio_rng_priv *priv = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = virtio_find_vqs(dev, 1, &priv->rng_vq);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static const struct dm_rng_ops virtio_rng_ops = {
> +	.read	= virtio_rng_read,
> +};
> +
> +U_BOOT_DRIVER(virtio_rng) = {
> +	.name	= VIRTIO_RNG_DRV_NAME,
> +	.id	= UCLASS_RNG,
> +	.bind	= virtio_rng_bind,
> +	.probe	= virtio_rng_probe,
> +	.remove = virtio_reset,
> +	.ops	= &virtio_rng_ops,
> +	.priv_auto_alloc_size = sizeof(struct virtio_rng_priv),
> +	.flags	= DM_FLAG_ACTIVE_DMA,
> +};
> diff --git a/include/virtio.h b/include/virtio.h
> index 654fdf1..561dcc3 100644
> --- a/include/virtio.h
> +++ b/include/virtio.h
> @@ -22,10 +22,12 @@
>  
>  #define VIRTIO_ID_NET		1 /* virtio net */
>  #define VIRTIO_ID_BLOCK		2 /* virtio block */
> -#define VIRTIO_ID_MAX_NUM	3
> +#define VIRTIO_ID_RNG		4 /* virtio rng */
> +#define VIRTIO_ID_MAX_NUM	5
>  
>  #define VIRTIO_NET_DRV_NAME	"virtio-net"
>  #define VIRTIO_BLK_DRV_NAME	"virtio-blk"
> +#define VIRTIO_RNG_DRV_NAME	"virtio-rng"
>  
>  /* Status byte for guest to report progress, and synchronize features */
>  
> -- 
> 2.7.4
> 

Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

[PATCH v3 1/8] dm: rng: Add random number generator(rng) uclass

[Ilias Apalodimas]

On Fri, Dec 13, 2019 at 12:44:20PM +0530, Sughosh Ganu wrote:
> Add a uclass for reading a random number seed from a random number
> generator device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile
>  create mode 100644 drivers/rng/rng-uclass.c
>  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
>  
>  source "drivers/reset/Kconfig"
>  
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
>  
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
>  
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
> new file mode 100644
> index 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
> new file mode 100644
> index 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c
> new file mode 100644
> index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size)
> +{
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h
> new file mode 100644
> index 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read
> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */
> +struct dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read
> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max);
> +};
> +
> +#endif /* _RNG_H_ */
> -- 
> 2.7.4
> 

Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

[PATCH v3 2/8] clk: stm32mp1: Add a clock entry for RNG1 device

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add an entry for allowing clock enablement for the random number generator
> peripheral, RNG1.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

Acked-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks.

[PATCH v3 3/8] stm32mp1: rng: Add a driver for random number generator(rng) device

[Patrick DELAUNAY]

Hi Sugosh,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a driver for the rng device found on stm32mp1 platforms. The driver provides
> a routine for reading the random number seed from the hardware device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>


Acked-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks.


> ---
>  drivers/rng/Kconfig        |   7 ++
>  drivers/rng/Makefile       |   1 +
>  drivers/rng/stm32mp1_rng.c | 158
> +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 166 insertions(+)
>  create mode 100644 drivers/rng/stm32mp1_rng.c
> 
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index dd44cc0..5fc11db
> 100644
> --- a/drivers/rng/Kconfig
> +++ b/drivers/rng/Kconfig
> @@ -5,3 +5,10 @@ config DM_RNG
>  	  Enable driver model for random number generator(rng) devices.
>  	  This interface is used to initialise the rng device and to
>  	  read the random seed from the device.
> +
> +config RNG_STM32MP1
> +       bool "Enable random number generator for STM32MP1"
> +       depends on ARCH_STM32MP && DM_RNG
> +       default n
> +       help
> +         Enable STM32MP1 rng driver.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 311705b..699beb3
> 100644
> --- a/drivers/rng/Makefile
> +++ b/drivers/rng/Makefile
> @@ -4,3 +4,4 @@
>  #
> 
>  obj-$(CONFIG_DM_RNG) += rng-uclass.o
> +obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
> diff --git a/drivers/rng/stm32mp1_rng.c b/drivers/rng/stm32mp1_rng.c new file
> mode 100644 index 0000000..5cd736d
> --- /dev/null
> +++ b/drivers/rng/stm32mp1_rng.c
> @@ -0,0 +1,158 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <clk.h>
> +#include <dm.h>
> +#include <reset.h>
> +#include <rng.h>
> +
> +#include <asm/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/kernel.h>
> +
> +#define RNG_CR 0x00
> +#define RNG_CR_RNGEN BIT(2)
> +#define RNG_CR_CED BIT(5)
> +
> +#define RNG_SR 0x04
> +#define RNG_SR_SEIS BIT(6)
> +#define RNG_SR_CEIS BIT(5)
> +#define RNG_SR_SECS BIT(2)
> +#define RNG_SR_DRDY BIT(0)
> +
> +#define RNG_DR 0x08
> +
> +struct stm32_rng_platdata {
> +	fdt_addr_t base;
> +	struct clk clk;
> +	struct reset_ctl rst;
> +};
> +
> +static int stm32_rng_read(struct udevice *dev, void *data, size_t len)
> +{
> +	int retval = 0, i;
> +	u32 sr, count, reg;
> +	size_t increment;
> +	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
> +
> +	while (len > 0) {
> +		retval = readl_poll_timeout(pdata->base + RNG_SR, sr,
> +					    sr & RNG_SR_DRDY, 10000);
> +		if (retval)
> +			return retval;
> +
> +		if (sr & (RNG_SR_SEIS | RNG_SR_SECS)) {
> +			/* As per SoC TRM */
> +			clrbits_le32(pdata->base + RNG_SR, RNG_SR_SEIS);
> +			for (i = 0; i < 12; i++)
> +				readl(pdata->base + RNG_DR);
> +			if (readl(pdata->base + RNG_SR) & RNG_SR_SEIS) {
> +				printf("RNG Noise");
> +				return -EIO;
> +			}
> +			/* start again */
> +			continue;
> +		}
> +
> +		count = 4;
> +		while (len && count) {
> +			reg = readl(pdata->base + RNG_DR);
> +			memcpy(data, &reg, min(len, sizeof(u32)));
> +			increment = min(len, sizeof(u32));
> +			data += increment;
> +			retval += increment;
> +			len -= increment;
> +			count--;
> +		}
> +	}
> +
> +	return retval;
> +}
> +
> +static int stm32_rng_init(struct stm32_rng_platdata *pdata) {
> +	int err;
> +
> +	err = clk_enable(&pdata->clk);
> +	if (err)
> +		return err;
> +
> +	/* Disable CED */
> +	writel(RNG_CR_RNGEN | RNG_CR_CED, pdata->base + RNG_CR);
> +
> +	/* clear error indicators */
> +	writel(0, pdata->base + RNG_SR);
> +
> +	return 0;
> +}
> +
> +static int stm32_rng_cleanup(struct stm32_rng_platdata *pdata) {
> +
> +	writel(0, pdata->base + RNG_CR);
> +
> +	return clk_disable(&pdata->clk);
> +}
> +
> +static int stm32_rng_probe(struct udevice *dev) {
> +	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
> +
> +	reset_assert(&pdata->rst);
> +	udelay(20);
> +	reset_deassert(&pdata->rst);
> +
> +	return stm32_rng_init(pdata);
> +}
> +
> +static int stm32_rng_remove(struct udevice *dev) {
> +	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
> +
> +	return stm32_rng_cleanup(pdata);
> +}
> +
> +static int stm32_rng_ofdata_to_platdata(struct udevice *dev) {
> +	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);
> +	int err;
> +
> +	pdata->base = dev_read_addr(dev);
> +	if (!pdata->base)
> +		return -ENOMEM;
> +
> +	err = clk_get_by_index(dev, 0, &pdata->clk);
> +	if (err)
> +		return err;
> +
> +	err = reset_get_by_index(dev, 0, &pdata->rst);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static const struct dm_rng_ops stm32_rng_ops = {
> +	.read = stm32_rng_read,
> +};
> +
> +static const struct udevice_id stm32_rng_match[] = {
> +	{
> +		.compatible = "st,stm32-rng",
> +	},
> +	{},
> +};
> +
> +U_BOOT_DRIVER(stm32_rng) = {
> +	.name = "stm32-rng",
> +	.id = UCLASS_RNG,
> +	.of_match = stm32_rng_match,
> +	.ops = &stm32_rng_ops,
> +	.probe = stm32_rng_probe,
> +	.remove = stm32_rng_remove,
> +	.platdata_auto_alloc_size = sizeof(struct stm32_rng_platdata),
> +	.ofdata_to_platdata = stm32_rng_ofdata_to_platdata, };
> --
> 2.7.4

[PATCH v3 1/8] dm: rng: Add random number generator(rng) uclass

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a uclass for reading a random number seed from a random number generator
> device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks.

> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile  create mode 100644 drivers/rng/rng-
> uclass.c  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
> 
>  source "drivers/reset/Kconfig"
> 
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
> 
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
> 
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index
> 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index
> 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode
> 100644 index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) {
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index
> 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read
> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> +dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read
> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max); };
> +
> +#endif /* _RNG_H_ */
> --
> 2.7.4

[PATCH v3 4/8] configs: stm32mp15: Enable random number generator(rng) device

[Patrick DELAUNAY]

Hi,

> Sent: vendredi 13 décembre 2019 08:14
> 
> Enable support for the rng device on the stm32mp15 configs.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>


Acked-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks.

> ---
>  configs/stm32mp15_basic_defconfig   | 2 ++
>  configs/stm32mp15_optee_defconfig   | 2 ++
>  configs/stm32mp15_trusted_defconfig | 2 ++
>  3 files changed, 6 insertions(+)
> 
> diff --git a/configs/stm32mp15_basic_defconfig
> b/configs/stm32mp15_basic_defconfig
> index 358c2cd..5ca40e0 100644
> --- a/configs/stm32mp15_basic_defconfig
> +++ b/configs/stm32mp15_basic_defconfig
> @@ -143,3 +143,5 @@ CONFIG_VIDEO_STM32_DSI=y
>  CONFIG_VIDEO_STM32_MAX_XRES=1280
>  CONFIG_VIDEO_STM32_MAX_YRES=800
>  CONFIG_FDT_FIXUP_PARTITIONS=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_STM32MP1=y
> diff --git a/configs/stm32mp15_optee_defconfig
> b/configs/stm32mp15_optee_defconfig
> index a065d3e..b161cd1 100644
> --- a/configs/stm32mp15_optee_defconfig
> +++ b/configs/stm32mp15_optee_defconfig
> @@ -127,3 +127,5 @@ CONFIG_VIDEO_STM32_DSI=y
>  CONFIG_VIDEO_STM32_MAX_XRES=1280
>  CONFIG_VIDEO_STM32_MAX_YRES=800
>  CONFIG_FDT_FIXUP_PARTITIONS=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_STM32MP1=y
> diff --git a/configs/stm32mp15_trusted_defconfig
> b/configs/stm32mp15_trusted_defconfig
> index 632f11f..ddf244d 100644
> --- a/configs/stm32mp15_trusted_defconfig
> +++ b/configs/stm32mp15_trusted_defconfig
> @@ -126,3 +126,5 @@ CONFIG_VIDEO_STM32_DSI=y
>  CONFIG_VIDEO_STM32_MAX_XRES=1280
>  CONFIG_VIDEO_STM32_MAX_YRES=800
>  CONFIG_FDT_FIXUP_PARTITIONS=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_STM32MP1=y
> --
> 2.7.4

[PATCH v3 6/8] configs: sandbox: Enable random number generator(rng) device

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Enable support for random number generator on sandbox configs. This is aimed
> primarily at adding unit test support for rng uclass.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks

> ---
>  configs/sandbox64_defconfig | 2 ++
>  configs/sandbox_defconfig   | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig index
> cc536ff..a21d832 100644
> --- a/configs/sandbox64_defconfig
> +++ b/configs/sandbox64_defconfig
> @@ -158,6 +158,8 @@ CONFIG_REGULATOR_RK8XX=y
> CONFIG_REGULATOR_S5M8767=y  CONFIG_DM_REGULATOR_SANDBOX=y
> CONFIG_REGULATOR_TPS65090=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_SANDBOX=y
>  CONFIG_DM_PWM=y
>  CONFIG_PWM_SANDBOX=y
>  CONFIG_RAM=y
> diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig index
> 64245f7..9bdc0f5 100644
> --- a/configs/sandbox_defconfig
> +++ b/configs/sandbox_defconfig
> @@ -179,6 +179,8 @@ CONFIG_REGULATOR_RK8XX=y
> CONFIG_REGULATOR_S5M8767=y  CONFIG_DM_REGULATOR_SANDBOX=y
> CONFIG_REGULATOR_TPS65090=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_SANDBOX=y
>  CONFIG_DM_PWM=y
>  CONFIG_PWM_SANDBOX=y
>  CONFIG_RAM=y
> --
> 2.7.4

[PATCH v3 1/8] dm: rng: Add random number generator(rng) uclass

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a uclass for reading a random number seed from a random number generator
> device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile  create mode 100644 drivers/rng/rng-
> uclass.c  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
> 
>  source "drivers/reset/Kconfig"
> 
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
> 
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
> 
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index
> 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index
> 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode
> 100644 index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) {
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index
> 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read

Missing return value here, I propose:

@return zero on success, or -ve error code.

> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> +dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read

Missing return value here, I propose: 

@return zero on success, or -ve error code.

> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max); };
> +
> +#endif /* _RNG_H_ */
> --
> 2.7.4

Patrick

[PATCH v3 5/8] sandbox: rng: Add a random number generator(rng) driver

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a sandbox driver for random number generation. Mostly aimed at providing a
> unit test for rng uclass.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  arch/sandbox/dts/test.dts |  4 ++++
>  drivers/rng/Kconfig       |  7 +++++++
>  drivers/rng/Makefile      |  1 +
>  drivers/rng/sandbox_rng.c | 36 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 48 insertions(+)
>  create mode 100644 drivers/rng/sandbox_rng.c
> 
> diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts index
> fdb08f2..2c85540 100644
> --- a/arch/sandbox/dts/test.dts
> +++ b/arch/sandbox/dts/test.dts
> @@ -599,6 +599,10 @@
>  		reset-names = "other", "test";
>  	};
> 
> +	rng at 0 {
> +		compatible = "sandbox,sandbox-rng";
> +	};
> +
>  	rproc_1: rproc at 1 {
>  		compatible = "sandbox,test-processor";
>  		remoteproc-name = "remoteproc-test-dev1"; diff --git
> a/drivers/rng/Kconfig b/drivers/rng/Kconfig index 5fc11db..3a1d3f0 100644
> --- a/drivers/rng/Kconfig
> +++ b/drivers/rng/Kconfig
> @@ -6,6 +6,13 @@ config DM_RNG
>  	  This interface is used to initialise the rng device and to
>  	  read the random seed from the device.
> 
> +config RNG_SANDBOX
> +       bool "Sandbox random number generator"
> +       depends on SANDBOX && DM_RNG
> +       help
> +         Enable random number generator for sandbox. This is an
> +	 emulation of a rng device.
> +
>  config RNG_STM32MP1
>         bool "Enable random number generator for STM32MP1"
>         depends on ARCH_STM32MP && DM_RNG diff --git a/drivers/rng/Makefile
> b/drivers/rng/Makefile index 699beb3..3517005 100644
> --- a/drivers/rng/Makefile
> +++ b/drivers/rng/Makefile
> @@ -4,4 +4,5 @@
>  #
> 
>  obj-$(CONFIG_DM_RNG) += rng-uclass.o
> +obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o
>  obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o diff --git
> a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c new file mode 100644
> index 0000000..c5be552
> --- /dev/null
> +++ b/drivers/rng/sandbox_rng.c
> @@ -0,0 +1,36 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +static unsigned long random = 0xdeadbeef;
> +
> +static int sandbox_rng_read(struct udevice *dev, void *data, size_t
> +len) {

Add protection on length  I think: 
	If (len != sizeof(random))
		retrun - EINVAL;

or treat the case len > 4 with loop ?

> +	random ^= ~0UL;
> +	*(unsigned long *)data = random;
> +
> +	return sizeof(random);

Read is OK, so I think the correct return value is 0:

	return 0;

NB: result (int) can be not enough to return the value read (size_t)

PS: it not really a random generator here but simple sequence
       0xdeadbeef -> 0x21524110 -> 0xdeadbeef

      It is enough for unitary test, but is is enough for sandbox ?
      we could reused PRNG code from lib/rand.c ?

> +}
> +
> +static const struct dm_rng_ops sandbox_rng_ops = {
> +	.read = sandbox_rng_read,
> +};
> +
> +static const struct udevice_id sandbox_rng_match[] = {
> +	{
> +		.compatible = "sandbox,sandbox-rng",
> +	},
> +	{},
> +};
> +
> +U_BOOT_DRIVER(sandbox_rng) = {
> +	.name = "sandbox-rng",
> +	.id = UCLASS_RNG,
> +	.of_match = sandbox_rng_match,
> +	.ops = &sandbox_rng_ops,
> +};
> --
> 2.7.4

[PATCH v3 7/8] test: rng: Add basic test for random number generator(rng) uclass

[Patrick DELAUNAY]

Hi,

> -----Original Message-----
> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> To: u-boot at lists.denx.de
> Subject: [PATCH v3 7/8] test: rng: Add basic test for random number
> generator(rng) uclass
> 
> Add a unit test for testing the rng uclass functionality using the sandbox rng
> driver.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  test/dm/Makefile |  1 +
>  test/dm/rng.c    | 26 ++++++++++++++++++++++++++
>  2 files changed, 27 insertions(+)
>  create mode 100644 test/dm/rng.c
> 
> diff --git a/test/dm/Makefile b/test/dm/Makefile index 0c2fd5c..f61bf65 100644
> --- a/test/dm/Makefile
> +++ b/test/dm/Makefile
> @@ -65,4 +65,5 @@ obj-$(CONFIG_VIRTIO_SANDBOX) += virtio.o
>  obj-$(CONFIG_DMA) += dma.o
>  obj-$(CONFIG_DM_MDIO) += mdio.o
>  obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o
> +obj-$(CONFIG_DM_RNG) += rng.o
>  endif
> diff --git a/test/dm/rng.c b/test/dm/rng.c new file mode 100644 index
> 0000000..879e80a
> --- /dev/null
> +++ b/test/dm/rng.c
> @@ -0,0 +1,26 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +#include <dm/test.h>
> +#include <test/ut.h>
> +
> +/* Basic test of the rng uclass */
> +static int dm_test_rng_read(struct unit_test_state *uts) {
> +	unsigned long val1 = 0, val2 = 0;
> +	struct udevice *dev;
> +
> +	ut_assertok(uclass_get_device(UCLASS_RNG, 0, &dev));
> +	ut_assertnonnull(dev);
> +	dm_rng_read(dev, &val1, sizeof(val1));
> +	dm_rng_read(dev, &val2, sizeof(val2));

Test return:

ut_assertok(dm_rng_read(dev, &val1, sizeof(val1)));
ut_assertok(dm_rng_read(dev, &val2, sizeof(val2)))

> +	ut_assert(val1 != val2);

You can also check the values as the sandbox driver use only the 2 next values :

ut_asserteq(0x21524110, val1);
ut_asserteq(0xDEADBEEF, val2);

> +	return 0;
> +}
> +DM_TEST(dm_test_rng_read, DM_TESTF_SCAN_PDATA |
> DM_TESTF_SCAN_FDT);
> --
> 2.7.4

Regards

Patrick

[PATCH v3 1/8] dm: rng: Add random number generator(rng) uclass

[Sughosh Ganu]

hi Patrick,

On Mon, 16 Dec 2019 at 17:43, Patrick DELAUNAY <patrick.delaunay@st.com>
wrote:

> Hi,
>
> > From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> > Sent: vendredi 13 décembre 2019 08:14
> >
> > Add a uclass for reading a random number seed from a random number
> generator
> > device.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> > ---
> >  drivers/Kconfig          |  2 ++
> >  drivers/Makefile         |  1 +
> >  drivers/rng/Kconfig      |  7 +++++++
> >  drivers/rng/Makefile     |  6 ++++++
> >  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
> >  include/dm/uclass-id.h   |  1 +
> >  include/rng.h            | 30 ++++++++++++++++++++++++++++++
> >  7 files changed, 70 insertions(+)
> >  create mode 100644 drivers/rng/Kconfig
> >  create mode 100644 drivers/rng/Makefile  create mode 100644
> drivers/rng/rng-
> > uclass.c  create mode 100644 include/rng.h
>

<snip>


> > diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> > 0000000..61d5da9
> > --- /dev/null
> > +++ b/include/rng.h
> > @@ -0,0 +1,30 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (c) 2019, Linaro Limited
> > + */
> > +
> > +#if !defined _RNG_H_
> > +#define _RNG_H_
> > +
> > +#include <dm.h>
> > +
> > +/**
> > + * dm_rng_read() - read a random number seed from the rng device
> > + * @buffer:  input buffer to put the read random seed into
> > + * @size:    number of bytes of random seed read
>
> Missing return value here, I propose:
>
> @return zero on success, or -ve error code.
>

Ok. Will add.


>
> > + *
> > + */
> > +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> > +
> > +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> > +dm_rng_ops {
> > +     /**
> > +      * @read() - read a random number seed
> > +      *
> > +      * @data:       input buffer to read the random seed
> > +      * @max:        total number of bytes to read
>
> Missing return value here, I propose:
>
> @return zero on success, or -ve error code.
>

Ok. Will add.

-sughosh

[PATCH v3 5/8] sandbox: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

hi Patrick,

On Mon, 16 Dec 2019 at 18:00, Patrick DELAUNAY <patrick.delaunay@st.com>
wrote:

> Hi,
>
> > From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> > Sent: vendredi 13 décembre 2019 08:14
> >
> > Add a sandbox driver for random number generation. Mostly aimed at
> providing a
> > unit test for rng uclass.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> > ---
> >  arch/sandbox/dts/test.dts |  4 ++++
> >  drivers/rng/Kconfig       |  7 +++++++
> >  drivers/rng/Makefile      |  1 +
> >  drivers/rng/sandbox_rng.c | 36 ++++++++++++++++++++++++++++++++++++
> >  4 files changed, 48 insertions(+)
> >  create mode 100644 drivers/rng/sandbox_rng.c
>

<snip>

>
> > a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c new file mode
> 100644
> > index 0000000..c5be552
> > --- /dev/null
> > +++ b/drivers/rng/sandbox_rng.c
> > @@ -0,0 +1,36 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2019, Linaro Limited
> > + */
> > +
> > +#include <common.h>
> > +#include <dm.h>
> > +#include <rng.h>
> > +
> > +static unsigned long random = 0xdeadbeef;
> > +
> > +static int sandbox_rng_read(struct udevice *dev, void *data, size_t
> > +len) {
>
> Add protection on length  I think:
>         If (len != sizeof(random))
>                 retrun - EINVAL;
>

Ok. Will add this check.


>
> or treat the case len > 4 with loop ?
>
> > +     random ^= ~0UL;
> > +     *(unsigned long *)data = random;
> > +
> > +     return sizeof(random);
>
> Read is OK, so I think the correct return value is 0:
>

Ok. Will change.


>
>         return 0;
>
> NB: result (int) can be not enough to return the value read (size_t)
>
> PS: it not really a random generator here but simple sequence
>        0xdeadbeef -> 0x21524110 -> 0xdeadbeef
>
>       It is enough for unitary test, but is is enough for sandbox ?
>       we could reused PRNG code from lib/rand.c ?
>

I actually wrote this solely from the point of view of adding a unit test
for the rng uclass. For which i think the simple sequence above should
suffice. Do you have a strong opinion on this. If so, i can change the
logic.

-sughosh

>
>

[PATCH v3 7/8] test: rng: Add basic test for random number generator(rng) uclass

[Sughosh Ganu]

hi Patrick,

On Mon, 16 Dec 2019 at 18:12, Patrick DELAUNAY <patrick.delaunay@st.com>
wrote:

> Hi,
>
> > -----Original Message-----
> > From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> > Sent: vendredi 13 décembre 2019 08:14
> > To: u-boot at lists.denx.de
> > Subject: [PATCH v3 7/8] test: rng: Add basic test for random number
> > generator(rng) uclass
> >
> > Add a unit test for testing the rng uclass functionality using the
> sandbox rng
> > driver.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> > ---
> >  test/dm/Makefile |  1 +
> >  test/dm/rng.c    | 26 ++++++++++++++++++++++++++
> >  2 files changed, 27 insertions(+)
> >  create mode 100644 test/dm/rng.c
>

<snip>


> >
> > diff --git a/test/dm/Makefile b/test/dm/Makefile index 0c2fd5c..f61bf65
> 100644
> > --- a/test/dm/Makefile
> > +++ b/test/dm/Makefile
> > @@ -65,4 +65,5 @@ obj-$(CONFIG_VIRTIO_SANDBOX) += virtio.o
> >  obj-$(CONFIG_DMA) += dma.o
> >  obj-$(CONFIG_DM_MDIO) += mdio.o
> >  obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o
> > +obj-$(CONFIG_DM_RNG) += rng.o
> >  endif
> > diff --git a/test/dm/rng.c b/test/dm/rng.c new file mode 100644 index
> > 0000000..879e80a
> > --- /dev/null
> > +++ b/test/dm/rng.c
> > @@ -0,0 +1,26 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2019, Linaro Limited
> > + */
> > +
> > +#include <common.h>
> > +#include <dm.h>
> > +#include <rng.h>
> > +#include <dm/test.h>
> > +#include <test/ut.h>
> > +
> > +/* Basic test of the rng uclass */
> > +static int dm_test_rng_read(struct unit_test_state *uts) {
> > +     unsigned long val1 = 0, val2 = 0;
> > +     struct udevice *dev;
> > +
> > +     ut_assertok(uclass_get_device(UCLASS_RNG, 0, &dev));
> > +     ut_assertnonnull(dev);
> > +     dm_rng_read(dev, &val1, sizeof(val1));
> > +     dm_rng_read(dev, &val2, sizeof(val2));
>
> Test return:
>
> ut_assertok(dm_rng_read(dev, &val1, sizeof(val1)));
> ut_assertok(dm_rng_read(dev, &val2, sizeof(val2)))
>

Ok. Will add.


>
> > +     ut_assert(val1 != val2);
>
> You can also check the values as the sandbox driver use only the 2 next
> values :
>
> ut_asserteq(0x21524110, val1);
> ut_asserteq(0xDEADBEEF, val2);
>

Ok. Will add.

-sughosh