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1/*2 * Hardware Random Number Generator support for Cavium Networks3 * Octeon processor family.4 *5 * This file is subject to the terms and conditions of the GNU General Public6 * License. See the file "COPYING" in the main directory of this archive7 * for more details.8 *9 * Copyright (C) 2009 Cavium Networks10 */11 12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/device.h>15#include <linux/hw_random.h>16#include <linux/io.h>17#include <linux/gfp.h>18 19#include <asm/octeon/octeon.h>20#include <asm/octeon/cvmx-rnm-defs.h>21 22struct octeon_rng {23 struct hwrng ops;24 void __iomem *control_status;25 void __iomem *result;26};27 28static int octeon_rng_init(struct hwrng *rng)29{30 union cvmx_rnm_ctl_status ctl;31 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);32 33 ctl.u64 = 0;34 ctl.s.ent_en = 1; /* Enable the entropy source. */35 ctl.s.rng_en = 1; /* Enable the RNG hardware. */36 cvmx_write_csr((unsigned long)p->control_status, ctl.u64);37 return 0;38}39 40static void octeon_rng_cleanup(struct hwrng *rng)41{42 union cvmx_rnm_ctl_status ctl;43 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);44 45 ctl.u64 = 0;46 /* Disable everything. */47 cvmx_write_csr((unsigned long)p->control_status, ctl.u64);48}49 50static int octeon_rng_data_read(struct hwrng *rng, u32 *data)51{52 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);53 54 *data = cvmx_read64_uint32((unsigned long)p->result);55 return sizeof(u32);56}57 58static int octeon_rng_probe(struct platform_device *pdev)59{60 struct resource *res_ports;61 struct resource *res_result;62 struct octeon_rng *rng;63 int ret;64 struct hwrng ops = {65 .name = "octeon",66 .init = octeon_rng_init,67 .cleanup = octeon_rng_cleanup,68 .data_read = octeon_rng_data_read69 };70 71 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);72 if (!rng)73 return -ENOMEM;74 75 res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);76 if (!res_ports)77 return -ENOENT;78 79 res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);80 if (!res_result)81 return -ENOENT;82 83 84 rng->control_status = devm_ioremap(&pdev->dev,85 res_ports->start,86 sizeof(u64));87 if (!rng->control_status)88 return -ENOENT;89 90 rng->result = devm_ioremap(&pdev->dev,91 res_result->start,92 sizeof(u64));93 if (!rng->result)94 return -ENOENT;95 96 rng->ops = ops;97 98 platform_set_drvdata(pdev, &rng->ops);99 ret = devm_hwrng_register(&pdev->dev, &rng->ops);100 if (ret)101 return -ENOENT;102 103 dev_info(&pdev->dev, "Octeon Random Number Generator\n");104 105 return 0;106}107 108static struct platform_driver octeon_rng_driver = {109 .driver = {110 .name = "octeon_rng",111 },112 .probe = octeon_rng_probe,113};114 115module_platform_driver(octeon_rng_driver);116 117MODULE_AUTHOR("David Daney");118MODULE_LICENSE("GPL");119