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 + */ + +#include +#include +#include +#include + +#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 "); +MODULE_DESCRIPTION("PolarFire SoC (MPFS) hardware random driver");