From: Conor Dooley <[email protected]>
Add a driver to access the hardware random number generator on the
Polarfire SoC. The hwrng can only be accessed via the system controller,
so use the mailbox interface the system controller exposes to access the
hwrng.
Signed-off-by: Conor Dooley <[email protected]>
---
drivers/char/hw_random/Kconfig | 13 ++++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/mpfs-rng.c | 104 ++++++++++++++++++++++++++++++
3 files changed, 118 insertions(+)
create mode 100644 drivers/char/hw_random/mpfs-rng.c
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index a087156a5818..c3a9f17bf31c 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -385,6 +385,19 @@ config HW_RANDOM_PIC32
If unsure, say Y.
+config HW_RANDOM_POLARFIRE_SOC
+ tristate "Microchip PolarFire SoC Random Number Generator support"
+ depends on HW_RANDOM && POLARFIRE_SOC_SYS_CTRL
+ help
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on PolarFire SoC (MPFS).
+
+ To compile this driver as a module, choose M here. The
+ module will be called mfps_rng.
+
+ If unsure, say N.
+
+
config HW_RANDOM_MESON
tristate "Amlogic Meson Random Number Generator support"
depends on HW_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 584d47ba32f7..3e948cf04476 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -46,3 +46,4 @@ obj-$(CONFIG_HW_RANDOM_CCTRNG) += cctrng.o
obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o
obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o
obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o
+obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o
diff --git a/drivers/char/hw_random/mpfs-rng.c b/drivers/char/hw_random/mpfs-rng.c
new file mode 100644
index 000000000000..5813da617a48
--- /dev/null
+++ b/drivers/char/hw_random/mpfs-rng.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip PolarFire SoC (MPFS) hardware random driver
+ *
+ * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
+ *
+ * Author: Conor Dooley <[email protected]>
+ */
+
+#include <linux/module.h>
+#include <linux/hw_random.h>
+#include <linux/platform_device.h>
+#include <soc/microchip/mpfs.h>
+
+#define CMD_OPCODE 0x21
+#define CMD_DATA_SIZE 0U
+#define CMD_DATA NULL
+#define MBOX_OFFSET 0U
+#define RESP_OFFSET 0U
+#define RNG_RESP_BYTES 32U
+
+struct mpfs_rng {
+ struct mpfs_sys_controller *sys_controller;
+ struct hwrng rng;
+};
+
+static int mpfs_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct mpfs_rng *rng_priv = container_of(rng, struct mpfs_rng, rng);
+ u32 response_msg[RNG_RESP_BYTES / sizeof(u32)];
+ unsigned int count = 0, copy_size_bytes;
+ int ret;
+
+ struct mpfs_mss_response response = {
+ .resp_status = 0U,
+ .resp_msg = (u32 *)response_msg,
+ .resp_size = RNG_RESP_BYTES
+ };
+ struct mpfs_mss_msg msg = {
+ .cmd_opcode = CMD_OPCODE,
+ .cmd_data_size = CMD_DATA_SIZE,
+ .response = &response,
+ .cmd_data = CMD_DATA,
+ .mbox_offset = MBOX_OFFSET,
+ .resp_offset = RESP_OFFSET
+ };
+
+ while (count < max) {
+ ret = mpfs_blocking_transaction(rng_priv->sys_controller, &msg);
+ if (ret)
+ return ret;
+
+ copy_size_bytes = max - count > RNG_RESP_BYTES ? RNG_RESP_BYTES : max - count;
+ memcpy(buf + count, response_msg, copy_size_bytes);
+
+ count += copy_size_bytes;
+ if (!wait)
+ break;
+ }
+
+ return count;
+}
+
+static int mpfs_rng_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mpfs_rng *rng_priv;
+ int ret;
+
+ rng_priv = devm_kzalloc(dev, sizeof(*rng_priv), GFP_KERNEL);
+ if (!rng_priv)
+ return -ENOMEM;
+
+ rng_priv->sys_controller = mpfs_sys_controller_get(&pdev->dev);
+ if (IS_ERR(rng_priv->sys_controller))
+ return dev_err_probe(dev, PTR_ERR(rng_priv->sys_controller),
+ "Failed to register system controller hwrng sub device\n");
+
+ rng_priv->rng.read = mpfs_rng_read;
+ rng_priv->rng.name = pdev->name;
+ rng_priv->rng.quality = 1024;
+
+ platform_set_drvdata(pdev, rng_priv);
+
+ ret = devm_hwrng_register(&pdev->dev, &rng_priv->rng);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to register MPFS hwrng\n");
+
+ dev_info(&pdev->dev, "Registered MPFS hwrng\n");
+
+ return 0;
+}
+
+static struct platform_driver mpfs_rng_driver = {
+ .driver = {
+ .name = "mpfs-rng",
+ },
+ .probe = mpfs_rng_probe,
+};
+module_platform_driver(mpfs_rng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Conor Dooley <[email protected]>");
+MODULE_DESCRIPTION("PolarFire SoC (MPFS) hardware random driver");
--
2.35.1
On Fri, Apr 08, 2022 at 10:09:12AM +0000, [email protected] wrote:
> From: Conor Dooley <[email protected]>
>
> Add a driver to access the hardware random number generator on the
> Polarfire SoC. The hwrng can only be accessed via the system controller,
> so use the mailbox interface the system controller exposes to access the
> hwrng.
>
> Signed-off-by: Conor Dooley <[email protected]>
> ---
> drivers/char/hw_random/Kconfig | 13 ++++
> drivers/char/hw_random/Makefile | 1 +
> drivers/char/hw_random/mpfs-rng.c | 104 ++++++++++++++++++++++++++++++
> 3 files changed, 118 insertions(+)
> create mode 100644 drivers/char/hw_random/mpfs-rng.c
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
The dependency on HW_RANDOM is redundant so this patch removes it.
As this driver seems to cross-compile just fine we could also enable
COMPILE_TEST.
Signed-off-by: Herbert Xu <[email protected]>
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 18aa97974b8b..dad084c0ecee 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -387,7 +387,7 @@ config HW_RANDOM_PIC32
config HW_RANDOM_POLARFIRE_SOC
tristate "Microchip PolarFire SoC Random Number Generator support"
- depends on HW_RANDOM && POLARFIRE_SOC_SYS_CTRL
+ depends on POLARFIRE_SOC_SYS_CTRL || COMPILE_TEST
help
This driver provides kernel-side support for the Random Number
Generator hardware found on PolarFire SoC (MPFS).
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt