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c7e2c4b37e
This function call was found to be unnecessary as there is no equivalent platform_get_drvdata() call to access the private data of the driver. Also, the private data is defined in this driver, so there is no risk of it being accessed outside of this driver file. Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Alexandru Ardelean <alex@shruggie.ro> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Microchip PolarFire SoC (MPFS) hardware random driver
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*
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* Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
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*
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* Author: Conor Dooley <conor.dooley@microchip.com>
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*/
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#include <linux/module.h>
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#include <linux/hw_random.h>
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#include <linux/platform_device.h>
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#include <soc/microchip/mpfs.h>
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#define CMD_OPCODE 0x21
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#define CMD_DATA_SIZE 0U
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#define CMD_DATA NULL
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#define MBOX_OFFSET 0U
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#define RESP_OFFSET 0U
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#define RNG_RESP_BYTES 32U
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struct mpfs_rng {
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struct mpfs_sys_controller *sys_controller;
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struct hwrng rng;
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};
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static int mpfs_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
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{
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struct mpfs_rng *rng_priv = container_of(rng, struct mpfs_rng, rng);
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u32 response_msg[RNG_RESP_BYTES / sizeof(u32)];
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unsigned int count = 0, copy_size_bytes;
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int ret;
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struct mpfs_mss_response response = {
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.resp_status = 0U,
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.resp_msg = (u32 *)response_msg,
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.resp_size = RNG_RESP_BYTES
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};
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struct mpfs_mss_msg msg = {
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.cmd_opcode = CMD_OPCODE,
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.cmd_data_size = CMD_DATA_SIZE,
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.response = &response,
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.cmd_data = CMD_DATA,
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.mbox_offset = MBOX_OFFSET,
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.resp_offset = RESP_OFFSET
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};
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while (count < max) {
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ret = mpfs_blocking_transaction(rng_priv->sys_controller, &msg);
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if (ret)
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return ret;
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copy_size_bytes = max - count > RNG_RESP_BYTES ? RNG_RESP_BYTES : max - count;
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memcpy(buf + count, response_msg, copy_size_bytes);
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count += copy_size_bytes;
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if (!wait)
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break;
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}
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return count;
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}
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static int mpfs_rng_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct mpfs_rng *rng_priv;
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int ret;
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rng_priv = devm_kzalloc(dev, sizeof(*rng_priv), GFP_KERNEL);
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if (!rng_priv)
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return -ENOMEM;
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rng_priv->sys_controller = mpfs_sys_controller_get(&pdev->dev);
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if (IS_ERR(rng_priv->sys_controller))
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return dev_err_probe(dev, PTR_ERR(rng_priv->sys_controller),
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"Failed to register system controller hwrng sub device\n");
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rng_priv->rng.read = mpfs_rng_read;
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rng_priv->rng.name = pdev->name;
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ret = devm_hwrng_register(&pdev->dev, &rng_priv->rng);
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if (ret)
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return dev_err_probe(&pdev->dev, ret, "Failed to register MPFS hwrng\n");
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dev_info(&pdev->dev, "Registered MPFS hwrng\n");
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return 0;
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}
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static struct platform_driver mpfs_rng_driver = {
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.driver = {
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.name = "mpfs-rng",
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},
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.probe = mpfs_rng_probe,
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};
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module_platform_driver(mpfs_rng_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
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MODULE_DESCRIPTION("PolarFire SoC (MPFS) hardware random driver");
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