1/* 2 * Hardware Random Number Generator support for Cavium Networks 3 * Octeon processor family. 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 * 9 * Copyright (C) 2009 Cavium Networks 10 */ 11 12#include <linux/module.h> 13#include <linux/init.h> 14#include <linux/platform_device.h> 15#include <linux/device.h> 16#include <linux/hw_random.h> 17#include <linux/io.h> 18#include <linux/gfp.h> 19 20#include <asm/octeon/octeon.h> 21#include <asm/octeon/cvmx-rnm-defs.h> 22 23struct octeon_rng { 24 struct hwrng ops; 25 void __iomem *control_status; 26 void __iomem *result; 27}; 28 29static int octeon_rng_init(struct hwrng *rng) 30{ 31 union cvmx_rnm_ctl_status ctl; 32 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); 33 34 ctl.u64 = 0; 35 ctl.s.ent_en = 1; /* Enable the entropy source. */ 36 ctl.s.rng_en = 1; /* Enable the RNG hardware. */ 37 cvmx_write_csr((u64)p->control_status, ctl.u64); 38 return 0; 39} 40 41static void octeon_rng_cleanup(struct hwrng *rng) 42{ 43 union cvmx_rnm_ctl_status ctl; 44 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); 45 46 ctl.u64 = 0; 47 /* Disable everything. */ 48 cvmx_write_csr((u64)p->control_status, ctl.u64); 49} 50 51static int octeon_rng_data_read(struct hwrng *rng, u32 *data) 52{ 53 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops); 54 55 *data = cvmx_read64_uint32((u64)p->result); 56 return sizeof(u32); 57} 58 59static int __devinit octeon_rng_probe(struct platform_device *pdev) 60{ 61 struct resource *res_ports; 62 struct resource *res_result; 63 struct octeon_rng *rng; 64 int ret; 65 struct hwrng ops = { 66 .name = "octeon", 67 .init = octeon_rng_init, 68 .cleanup = octeon_rng_cleanup, 69 .data_read = octeon_rng_data_read 70 }; 71 72 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); 73 if (!rng) 74 return -ENOMEM; 75 76 res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0); 77 if (!res_ports) 78 goto err_ports; 79 80 res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1); 81 if (!res_result) 82 goto err_ports; 83 84 85 rng->control_status = devm_ioremap_nocache(&pdev->dev, 86 res_ports->start, 87 sizeof(u64)); 88 if (!rng->control_status) 89 goto err_ports; 90 91 rng->result = devm_ioremap_nocache(&pdev->dev, 92 res_result->start, 93 sizeof(u64)); 94 if (!rng->result) 95 goto err_r; 96 97 rng->ops = ops; 98 99 dev_set_drvdata(&pdev->dev, &rng->ops); 100 ret = hwrng_register(&rng->ops); 101 if (ret) 102 goto err; 103 104 dev_info(&pdev->dev, "Octeon Random Number Generator\n"); 105 106 return 0; 107err: 108 devm_iounmap(&pdev->dev, rng->control_status); 109err_r: 110 devm_iounmap(&pdev->dev, rng->result); 111err_ports: 112 devm_kfree(&pdev->dev, rng); 113 return -ENOENT; 114} 115 116static int __exit octeon_rng_remove(struct platform_device *pdev) 117{ 118 struct hwrng *rng = dev_get_drvdata(&pdev->dev); 119 120 hwrng_unregister(rng); 121 122 return 0; 123} 124 125static struct platform_driver octeon_rng_driver = { 126 .driver = { 127 .name = "octeon_rng", 128 .owner = THIS_MODULE, 129 }, 130 .probe = octeon_rng_probe, 131 .remove = __exit_p(octeon_rng_remove), 132}; 133 134static int __init octeon_rng_mod_init(void) 135{ 136 return platform_driver_register(&octeon_rng_driver); 137} 138 139static void __exit octeon_rng_mod_exit(void) 140{ 141 platform_driver_unregister(&octeon_rng_driver); 142} 143 144module_init(octeon_rng_mod_init); 145module_exit(octeon_rng_mod_exit); 146 147MODULE_AUTHOR("David Daney"); 148MODULE_LICENSE("GPL"); 149