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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 | /* * Hardware Random Number Generator support for Cavium Networks * Octeon processor family. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2009 Cavium Networks */ #include <linux/module.h> #include <linux/platform_device.h> #include <linux/device.h> #include <linux/hw_random.h> #include <linux/io.h> #include <linux/gfp.h> #include <asm/octeon/octeon.h> #include <asm/octeon/cvmx-rnm-defs.h> struct octeon_rng { struct hwrng ops; void __iomem *control_status; void __iomem *result; }; static int octeon_rng_init(struct hwrng *rng) { union cvmx_rnm_ctl_status ctl; struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); ctl.u64 = 0; ctl.s.ent_en = 1; /* Enable the entropy source. */ ctl.s.rng_en = 1; /* Enable the RNG hardware. */ cvmx_write_csr((u64)p->control_status, ctl.u64); return 0; } static void octeon_rng_cleanup(struct hwrng *rng) { union cvmx_rnm_ctl_status ctl; struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); ctl.u64 = 0; /* Disable everything. */ cvmx_write_csr((u64)p->control_status, ctl.u64); } static int octeon_rng_data_read(struct hwrng *rng, u32 *data) { struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); *data = cvmx_read64_uint32((u64)p->result); return sizeof(u32); } static int octeon_rng_probe(struct platform_device *pdev) { struct resource *res_ports; struct resource *res_result; struct octeon_rng *rng; int ret; struct hwrng ops = { .name = "octeon", .init = octeon_rng_init, .cleanup = octeon_rng_cleanup, .data_read = octeon_rng_data_read }; rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); if (!rng) return -ENOMEM; res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res_ports) return -ENOENT; res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1); if (!res_result) return -ENOENT; rng->control_status = devm_ioremap_nocache(&pdev->dev, res_ports->start, sizeof(u64)); if (!rng->control_status) return -ENOENT; rng->result = devm_ioremap_nocache(&pdev->dev, res_result->start, sizeof(u64)); if (!rng->result) return -ENOENT; rng->ops = ops; platform_set_drvdata(pdev, &rng->ops); ret = hwrng_register(&rng->ops); if (ret) return -ENOENT; dev_info(&pdev->dev, "Octeon Random Number Generator\n"); return 0; } static int __exit octeon_rng_remove(struct platform_device *pdev) { struct hwrng *rng = platform_get_drvdata(pdev); hwrng_unregister(rng); return 0; } static struct platform_driver octeon_rng_driver = { .driver = { .name = "octeon_rng", .owner = THIS_MODULE, }, .probe = octeon_rng_probe, .remove = __exit_p(octeon_rng_remove), }; module_platform_driver(octeon_rng_driver); MODULE_AUTHOR("David Daney"); MODULE_LICENSE("GPL"); |