123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104 |
- // 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");
|