/* * Copyright (C) 2006-2007 PA Semi, Inc * * Maintained by: Olof Johansson <olof@lixom.net> * * Driver for the PWRficient onchip rng * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */#include <linux/module.h>#include <linux/kernel.h>#include <linux/platform_device.h>#include <linux/hw_random.h>#include <asm/of_platform.h>#include <asm/io.h>#define SDCRNG_CTL_REG			0x00#define   SDCRNG_CTL_FVLD_M		0x0000f000#define   SDCRNG_CTL_FVLD_S		12#define   SDCRNG_CTL_KSZ		0x00000800#define   SDCRNG_CTL_RSRC_CRG		0x00000010#define   SDCRNG_CTL_RSRC_RRG		0x00000000#define   SDCRNG_CTL_CE			0x00000004#define   SDCRNG_CTL_RE			0x00000002#define   SDCRNG_CTL_DR			0x00000001#define   SDCRNG_CTL_SELECT_RRG_RNG	(SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)#define   SDCRNG_CTL_SELECT_CRG_RNG	(SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)#define SDCRNG_VAL_REG			0x20#define MODULE_NAME "pasemi_rng"static int pasemi_rng_data_present(struct hwrng *rng){	void __iomem *rng_regs = (void __iomem *)rng->priv;	return (in_le32(rng_regs + SDCRNG_CTL_REG)		& SDCRNG_CTL_FVLD_M) ? 1 : 0;}static int pasemi_rng_data_read(struct hwrng *rng, u32 *data){	void __iomem *rng_regs = (void __iomem *)rng->priv;	*data = in_le32(rng_regs + SDCRNG_VAL_REG);	return 4;}static int pasemi_rng_init(struct hwrng *rng){	void __iomem *rng_regs = (void __iomem *)rng->priv;	u32 ctl;	ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;	out_le32(rng_regs + SDCRNG_CTL_REG, ctl);	out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);	return 0;}static void pasemi_rng_cleanup(struct hwrng *rng){	void __iomem *rng_regs = (void __iomem *)rng->priv;	u32 ctl;	ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;	out_le32(rng_regs + SDCRNG_CTL_REG,		 in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);}static struct hwrng pasemi_rng = {	.name		= MODULE_NAME,	.init		= pasemi_rng_init,	.cleanup	= pasemi_rng_cleanup,	.data_present	= pasemi_rng_data_present,	.data_read	= pasemi_rng_data_read,};static int __devinit rng_probe(struct of_device *ofdev,			       const struct of_device_id *match){	void __iomem *rng_regs;	struct device_node *rng_np = ofdev->node;	struct resource res;	int err = 0;	err = of_address_to_resource(rng_np, 0, &res);	if (err)		return -ENODEV;	rng_regs = ioremap(res.start, 0x100);	if (!rng_regs)		return -ENOMEM;	pasemi_rng.priv = (unsigned long)rng_regs;	printk(KERN_INFO "Registering PA Semi RNG\n");	err = hwrng_register(&pasemi_rng);	if (err)		iounmap(rng_regs);	return err;}static int __devexit rng_remove(struct of_device *dev){	void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;	hwrng_unregister(&pasemi_rng);	iounmap(rng_regs);	return 0;}static struct of_device_id rng_match[] = {	{		.compatible      = "1682m-rng",	},	{},};static struct of_platform_driver rng_driver = {	.name		= "pasemi-rng",	.match_table	= rng_match,	.probe		= rng_probe,	.remove		= rng_remove,};static int __init rng_init(void){	return of_register_platform_driver(&rng_driver);}module_init(rng_init);static void __exit rng_exit(void){	of_unregister_platform_driver(&rng_driver);}module_exit(rng_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");