/*
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* Hardware Random Number Generator support for Cavium Networks
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* Octeon processor family.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2009 Cavium Networks
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*/
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/device.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/gfp.h>
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#include <asm/octeon/octeon.h>
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#include <asm/octeon/cvmx-rnm-defs.h>
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struct octeon_rng {
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struct hwrng ops;
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void __iomem *control_status;
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void __iomem *result;
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};
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static int octeon_rng_init(struct hwrng *rng)
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{
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union cvmx_rnm_ctl_status ctl;
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struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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ctl.u64 = 0;
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ctl.s.ent_en = 1; /* Enable the entropy source. */
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ctl.s.rng_en = 1; /* Enable the RNG hardware. */
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cvmx_write_csr((__force u64)p->control_status, ctl.u64);
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return 0;
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}
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static void octeon_rng_cleanup(struct hwrng *rng)
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{
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union cvmx_rnm_ctl_status ctl;
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struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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ctl.u64 = 0;
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/* Disable everything. */
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cvmx_write_csr((__force u64)p->control_status, ctl.u64);
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}
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static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
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{
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struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
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*data = cvmx_read64_uint32((__force u64)p->result);
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return sizeof(u32);
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}
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static int octeon_rng_probe(struct platform_device *pdev)
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{
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struct resource *res_ports;
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struct resource *res_result;
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struct octeon_rng *rng;
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int ret;
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struct hwrng ops = {
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.name = "octeon",
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.init = octeon_rng_init,
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.cleanup = octeon_rng_cleanup,
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.data_read = octeon_rng_data_read
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};
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rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
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if (!rng)
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return -ENOMEM;
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res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res_ports)
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return -ENOENT;
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res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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if (!res_result)
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return -ENOENT;
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rng->control_status = devm_ioremap(&pdev->dev,
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res_ports->start,
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sizeof(u64));
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if (!rng->control_status)
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return -ENOENT;
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rng->result = devm_ioremap(&pdev->dev,
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res_result->start,
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sizeof(u64));
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if (!rng->result)
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return -ENOENT;
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rng->ops = ops;
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platform_set_drvdata(pdev, &rng->ops);
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ret = devm_hwrng_register(&pdev->dev, &rng->ops);
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if (ret)
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return -ENOENT;
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dev_info(&pdev->dev, "Octeon Random Number Generator\n");
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return 0;
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}
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static struct platform_driver octeon_rng_driver = {
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.driver = {
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.name = "octeon_rng",
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},
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.probe = octeon_rng_probe,
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};
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module_platform_driver(octeon_rng_driver);
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MODULE_AUTHOR("David Daney");
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MODULE_LICENSE("GPL");
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