1 /* 2 * drivers/char/hw_random/ixp4xx-rng.c 3 * 4 * RNG driver for Intel IXP4xx family of NPUs 5 * 6 * Author: Deepak Saxena <dsaxena@plexity.net> 7 * 8 * Copyright 2005 (c) MontaVista Software, Inc. 9 * 10 * Fixes by Michael Buesch 11 * 12 * This file is licensed under the terms of the GNU General Public 13 * License version 2. This program is licensed "as is" without any 14 * warranty of any kind, whether express or implied. 15 */ 16 17 #include <linux/kernel.h> 18 #include <linux/types.h> 19 #include <linux/module.h> 20 #include <linux/moduleparam.h> 21 #include <linux/init.h> 22 #include <linux/bitops.h> 23 #include <linux/hw_random.h> 24 25 #include <asm/io.h> 26 #include <mach/hardware.h> 27 28 29 static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer) 30 { 31 void __iomem * rng_base = (void __iomem *)rng->priv; 32 33 *buffer = __raw_readl(rng_base); 34 35 return 4; 36 } 37 38 static struct hwrng ixp4xx_rng_ops = { 39 .name = "ixp4xx", 40 .data_read = ixp4xx_rng_data_read, 41 }; 42 43 static int __init ixp4xx_rng_init(void) 44 { 45 void __iomem * rng_base; 46 int err; 47 48 if (!cpu_is_ixp46x()) /* includes IXP455 */ 49 return -ENOSYS; 50 51 rng_base = ioremap(0x70002100, 4); 52 if (!rng_base) 53 return -ENOMEM; 54 ixp4xx_rng_ops.priv = (unsigned long)rng_base; 55 err = hwrng_register(&ixp4xx_rng_ops); 56 if (err) 57 iounmap(rng_base); 58 59 return err; 60 } 61 62 static void __exit ixp4xx_rng_exit(void) 63 { 64 void __iomem * rng_base = (void __iomem *)ixp4xx_rng_ops.priv; 65 66 hwrng_unregister(&ixp4xx_rng_ops); 67 iounmap(rng_base); 68 } 69 70 module_init(ixp4xx_rng_init); 71 module_exit(ixp4xx_rng_exit); 72 73 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 74 MODULE_DESCRIPTION("H/W Pseudo-Random Number Generator (RNG) driver for IXP45x/46x"); 75 MODULE_LICENSE("GPL"); 76