| 1 | /* |
| 2 | * drivers/net/ubi32-eth.c |
| 3 | * Ubicom32 hardware random number generator driver. |
| 4 | * |
| 5 | * (C) Copyright 2009, Ubicom, Inc. |
| 6 | * |
| 7 | * This file is part of the Ubicom32 Linux Kernel Port. |
| 8 | * |
| 9 | * The Ubicom32 Linux Kernel Port is free software: you can redistribute |
| 10 | * it and/or modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation, either version 2 of the |
| 12 | * License, or (at your option) any later version. |
| 13 | * |
| 14 | * The Ubicom32 Linux Kernel Port is distributed in the hope that it |
| 15 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 16 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 17 | * the GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the Ubicom32 Linux Kernel Port. If not, |
| 21 | * see <http://www.gnu.org/licenses/>. |
| 22 | * |
| 23 | * Ubicom32 implementation derived from (with many thanks): |
| 24 | * arch/m68knommu |
| 25 | * arch/blackfin |
| 26 | * arch/parisc |
| 27 | */ |
| 28 | |
| 29 | #include <linux/kernel.h> |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/hw_random.h> |
| 32 | #include <linux/delay.h> |
| 33 | #include <asm/io.h> |
| 34 | #include <asm/ip5000.h> |
| 35 | |
| 36 | #define MODULE_NAME "ubicom32_rng" |
| 37 | |
| 38 | static int ubicom32_rng_data_present(struct hwrng *rng, int wait) |
| 39 | { |
| 40 | int data, i; |
| 41 | |
| 42 | for (i = 0; i < 20; i++) { |
| 43 | data = *(int *)(TIMER_BASE + TIMER_TRN); |
| 44 | if (data || !wait) |
| 45 | break; |
| 46 | udelay(10); |
| 47 | } |
| 48 | return data; |
| 49 | } |
| 50 | |
| 51 | static int ubicom32_rng_data_read(struct hwrng *rng, u32 *data) |
| 52 | { |
| 53 | *data = *(int *)(TIMER_BASE + TIMER_TRN); |
| 54 | return 4; |
| 55 | } |
| 56 | |
| 57 | static int ubicom32_rng_init(struct hwrng *rng) |
| 58 | { |
| 59 | printk(KERN_INFO "ubicom32 rng init\n"); |
| 60 | *(int *)(TIMER_BASE + TIMER_TRN_CFG) = TIMER_TRN_CFG_ENABLE_OSC; |
| 61 | return 0; |
| 62 | } |
| 63 | |
| 64 | static void ubicom32_rng_cleanup(struct hwrng *rng) |
| 65 | { |
| 66 | printk(KERN_INFO "ubicom32 rng cleanup\n"); |
| 67 | *(int *)(TIMER_BASE + TIMER_TRN_CFG) = 0; |
| 68 | } |
| 69 | |
| 70 | static struct hwrng ubicom32_rng = { |
| 71 | .name = MODULE_NAME, |
| 72 | .init = ubicom32_rng_init, |
| 73 | .cleanup = ubicom32_rng_cleanup, |
| 74 | .data_present = ubicom32_rng_data_present, |
| 75 | .data_read = ubicom32_rng_data_read, |
| 76 | .priv = 0, |
| 77 | }; |
| 78 | |
| 79 | static int __init mod_init(void) |
| 80 | { |
| 81 | int err; |
| 82 | |
| 83 | printk(KERN_INFO "ubicom32 rng started\n"); |
| 84 | err = hwrng_register(&ubicom32_rng); |
| 85 | if (err) { |
| 86 | printk(KERN_ERR "ubicom32 rng register failed (%d)\n", |
| 87 | err); |
| 88 | } |
| 89 | |
| 90 | return err; |
| 91 | } |
| 92 | |
| 93 | static void __exit mod_exit(void) |
| 94 | { |
| 95 | printk(KERN_INFO "ubicom32 rng stopped\n"); |
| 96 | hwrng_unregister(&ubicom32_rng); |
| 97 | } |
| 98 | |
| 99 | module_init(mod_init); |
| 100 | module_exit(mod_exit); |
| 101 | |
| 102 | MODULE_LICENSE("GPL"); |
| 103 | MODULE_AUTHOR("Ubicom, Inc."); |
| 104 | MODULE_DESCRIPTION("H/W rng driver for ubicom32 processor"); |
| 105 | MODULE_VERSION("1:1.0.a"); |
| 106 | |
