1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * drivers/char/hw_random/ixp4xx-rng.c 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * RNG driver for Intel IXP4xx family of NPUs 5*4882a593Smuzhiyun * 6*4882a593Smuzhiyun * Author: Deepak Saxena <dsaxena@plexity.net> 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * Copyright 2005 (c) MontaVista Software, Inc. 9*4882a593Smuzhiyun * 10*4882a593Smuzhiyun * Fixes by Michael Buesch 11*4882a593Smuzhiyun * 12*4882a593Smuzhiyun * This file is licensed under the terms of the GNU General Public 13*4882a593Smuzhiyun * License version 2. This program is licensed "as is" without any 14*4882a593Smuzhiyun * warranty of any kind, whether express or implied. 15*4882a593Smuzhiyun */ 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun #include <linux/kernel.h> 18*4882a593Smuzhiyun #include <linux/types.h> 19*4882a593Smuzhiyun #include <linux/module.h> 20*4882a593Smuzhiyun #include <linux/moduleparam.h> 21*4882a593Smuzhiyun #include <linux/init.h> 22*4882a593Smuzhiyun #include <linux/bitops.h> 23*4882a593Smuzhiyun #include <linux/hw_random.h> 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun #include <asm/io.h> 26*4882a593Smuzhiyun #include <mach/hardware.h> 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun ixp4xx_rng_data_read(struct hwrng * rng,u32 * buffer)29*4882a593Smuzhiyunstatic int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer) 30*4882a593Smuzhiyun { 31*4882a593Smuzhiyun void __iomem * rng_base = (void __iomem *)rng->priv; 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun *buffer = __raw_readl(rng_base); 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun return 4; 36*4882a593Smuzhiyun } 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun static struct hwrng ixp4xx_rng_ops = { 39*4882a593Smuzhiyun .name = "ixp4xx", 40*4882a593Smuzhiyun .data_read = ixp4xx_rng_data_read, 41*4882a593Smuzhiyun }; 42*4882a593Smuzhiyun ixp4xx_rng_init(void)43*4882a593Smuzhiyunstatic int __init ixp4xx_rng_init(void) 44*4882a593Smuzhiyun { 45*4882a593Smuzhiyun void __iomem * rng_base; 46*4882a593Smuzhiyun int err; 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun if (!cpu_is_ixp46x()) /* includes IXP455 */ 49*4882a593Smuzhiyun return -ENOSYS; 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun rng_base = ioremap(0x70002100, 4); 52*4882a593Smuzhiyun if (!rng_base) 53*4882a593Smuzhiyun return -ENOMEM; 54*4882a593Smuzhiyun ixp4xx_rng_ops.priv = (unsigned long)rng_base; 55*4882a593Smuzhiyun err = hwrng_register(&ixp4xx_rng_ops); 56*4882a593Smuzhiyun if (err) 57*4882a593Smuzhiyun iounmap(rng_base); 58*4882a593Smuzhiyun 59*4882a593Smuzhiyun return err; 60*4882a593Smuzhiyun } 61*4882a593Smuzhiyun ixp4xx_rng_exit(void)62*4882a593Smuzhiyunstatic void __exit ixp4xx_rng_exit(void) 63*4882a593Smuzhiyun { 64*4882a593Smuzhiyun void __iomem * rng_base = (void __iomem *)ixp4xx_rng_ops.priv; 65*4882a593Smuzhiyun 66*4882a593Smuzhiyun hwrng_unregister(&ixp4xx_rng_ops); 67*4882a593Smuzhiyun iounmap(rng_base); 68*4882a593Smuzhiyun } 69*4882a593Smuzhiyun 70*4882a593Smuzhiyun module_init(ixp4xx_rng_init); 71*4882a593Smuzhiyun module_exit(ixp4xx_rng_exit); 72*4882a593Smuzhiyun 73*4882a593Smuzhiyun MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 74*4882a593Smuzhiyun MODULE_DESCRIPTION("H/W Pseudo-Random Number Generator (RNG) driver for IXP45x/46x"); 75*4882a593Smuzhiyun MODULE_LICENSE("GPL"); 76