132 lines
3.2 KiB
C
132 lines
3.2 KiB
C
/*
|
|
* Generic PowerPC 44x RNG driver
|
|
*
|
|
* Copyright 2011 IBM Corporation
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; version 2 of the License.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/hw_random.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/io.h>
|
|
|
|
#include "crypto4xx_core.h"
|
|
#include "crypto4xx_trng.h"
|
|
#include "crypto4xx_reg_def.h"
|
|
|
|
#define PPC4XX_TRNG_CTRL 0x0008
|
|
#define PPC4XX_TRNG_CTRL_DALM 0x20
|
|
#define PPC4XX_TRNG_STAT 0x0004
|
|
#define PPC4XX_TRNG_STAT_B 0x1
|
|
#define PPC4XX_TRNG_DATA 0x0000
|
|
|
|
static int ppc4xx_trng_data_present(struct hwrng *rng, int wait)
|
|
{
|
|
struct crypto4xx_device *dev = (void *)rng->priv;
|
|
int busy, i, present = 0;
|
|
|
|
for (i = 0; i < 20; i++) {
|
|
busy = (in_le32(dev->trng_base + PPC4XX_TRNG_STAT) &
|
|
PPC4XX_TRNG_STAT_B);
|
|
if (!busy || !wait) {
|
|
present = 1;
|
|
break;
|
|
}
|
|
udelay(10);
|
|
}
|
|
return present;
|
|
}
|
|
|
|
static int ppc4xx_trng_data_read(struct hwrng *rng, u32 *data)
|
|
{
|
|
struct crypto4xx_device *dev = (void *)rng->priv;
|
|
*data = in_le32(dev->trng_base + PPC4XX_TRNG_DATA);
|
|
return 4;
|
|
}
|
|
|
|
static void ppc4xx_trng_enable(struct crypto4xx_device *dev, bool enable)
|
|
{
|
|
u32 device_ctrl;
|
|
|
|
device_ctrl = readl(dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
|
|
if (enable)
|
|
device_ctrl |= PPC4XX_TRNG_EN;
|
|
else
|
|
device_ctrl &= ~PPC4XX_TRNG_EN;
|
|
writel(device_ctrl, dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
|
|
}
|
|
|
|
static const struct of_device_id ppc4xx_trng_match[] = {
|
|
{ .compatible = "ppc4xx-rng", },
|
|
{ .compatible = "amcc,ppc460ex-rng", },
|
|
{ .compatible = "amcc,ppc440epx-rng", },
|
|
{},
|
|
};
|
|
|
|
void ppc4xx_trng_probe(struct crypto4xx_core_device *core_dev)
|
|
{
|
|
struct crypto4xx_device *dev = core_dev->dev;
|
|
struct device_node *trng = NULL;
|
|
struct hwrng *rng = NULL;
|
|
int err;
|
|
|
|
/* Find the TRNG device node and map it */
|
|
trng = of_find_matching_node(NULL, ppc4xx_trng_match);
|
|
if (!trng || !of_device_is_available(trng))
|
|
return;
|
|
|
|
dev->trng_base = of_iomap(trng, 0);
|
|
of_node_put(trng);
|
|
if (!dev->trng_base)
|
|
goto err_out;
|
|
|
|
rng = kzalloc(sizeof(*rng), GFP_KERNEL);
|
|
if (!rng)
|
|
goto err_out;
|
|
|
|
rng->name = KBUILD_MODNAME;
|
|
rng->data_present = ppc4xx_trng_data_present;
|
|
rng->data_read = ppc4xx_trng_data_read;
|
|
rng->priv = (unsigned long) dev;
|
|
core_dev->trng = rng;
|
|
ppc4xx_trng_enable(dev, true);
|
|
out_le32(dev->trng_base + PPC4XX_TRNG_CTRL, PPC4XX_TRNG_CTRL_DALM);
|
|
err = devm_hwrng_register(core_dev->device, core_dev->trng);
|
|
if (err) {
|
|
ppc4xx_trng_enable(dev, false);
|
|
dev_err(core_dev->device, "failed to register hwrng (%d).\n",
|
|
err);
|
|
goto err_out;
|
|
}
|
|
return;
|
|
|
|
err_out:
|
|
of_node_put(trng);
|
|
iounmap(dev->trng_base);
|
|
kfree(rng);
|
|
dev->trng_base = NULL;
|
|
core_dev->trng = NULL;
|
|
}
|
|
|
|
void ppc4xx_trng_remove(struct crypto4xx_core_device *core_dev)
|
|
{
|
|
if (core_dev && core_dev->trng) {
|
|
struct crypto4xx_device *dev = core_dev->dev;
|
|
|
|
devm_hwrng_unregister(core_dev->device, core_dev->trng);
|
|
ppc4xx_trng_enable(dev, false);
|
|
iounmap(dev->trng_base);
|
|
kfree(core_dev->trng);
|
|
}
|
|
}
|
|
|
|
MODULE_ALIAS("ppc4xx_rng");
|