linux/drivers/char/hw_random/pasemi-rng.c
Olof Johansson 0d08a84770 [POWERPC] pasemi: Broaden specific references to 1682M
There will be more product numbers in the future than just PA6T-1682M,
but they will share much of the features. Remove some of the explicit
references and compatibility checks with 1682M, and replace most of them
with the more generic term "PWRficient".

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Doug Thompson <dougthompson@xmission.com>
2007-11-29 22:30:47 -06:00

156 lines
3.9 KiB
C

/*
* 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", },
{ .compatible = "pasemi,pwrficient-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");