122 lines
2.2 KiB
C
122 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
|
|
*
|
|
* Driver for Amlogic hardware random number generator
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <clk.h>
|
|
#include <dm.h>
|
|
#include <rng.h>
|
|
#include <asm/io.h>
|
|
|
|
struct meson_rng_plat {
|
|
fdt_addr_t base;
|
|
struct clk clk;
|
|
};
|
|
|
|
/**
|
|
* meson_rng_read() - fill buffer with random bytes
|
|
*
|
|
* @buffer: buffer to receive data
|
|
* @size: size of buffer
|
|
*
|
|
* Return: 0
|
|
*/
|
|
static int meson_rng_read(struct udevice *dev, void *data, size_t len)
|
|
{
|
|
struct meson_rng_plat *pdata = dev_get_plat(dev);
|
|
char *buffer = (char *)data;
|
|
|
|
while (len) {
|
|
u32 rand = readl(pdata->base);
|
|
size_t step;
|
|
|
|
if (len >= 4)
|
|
step = 4;
|
|
else
|
|
step = len;
|
|
memcpy(buffer, &rand, step);
|
|
buffer += step;
|
|
len -= step;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* meson_rng_probe() - probe rng device
|
|
*
|
|
* @dev: device
|
|
* Return: 0 if ok
|
|
*/
|
|
static int meson_rng_probe(struct udevice *dev)
|
|
{
|
|
struct meson_rng_plat *pdata = dev_get_plat(dev);
|
|
int err;
|
|
|
|
err = clk_enable(&pdata->clk);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* meson_rng_remove() - deinitialize rng device
|
|
*
|
|
* @dev: device
|
|
* Return: 0 if ok
|
|
*/
|
|
static int meson_rng_remove(struct udevice *dev)
|
|
{
|
|
struct meson_rng_plat *pdata = dev_get_plat(dev);
|
|
|
|
return clk_disable(&pdata->clk);
|
|
}
|
|
|
|
/**
|
|
* meson_rng_of_to_plat() - transfer device tree data to plaform data
|
|
*
|
|
* @dev: device
|
|
* Return: 0 if ok
|
|
*/
|
|
static int meson_rng_of_to_plat(struct udevice *dev)
|
|
{
|
|
struct meson_rng_plat *pdata = dev_get_plat(dev);
|
|
int err;
|
|
|
|
pdata->base = dev_read_addr(dev);
|
|
if (!pdata->base)
|
|
return -ENODEV;
|
|
|
|
/* Get optional "core" clock */
|
|
err = clk_get_by_name(dev, "core", &pdata->clk);
|
|
if (err && err != -ENODATA)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct dm_rng_ops meson_rng_ops = {
|
|
.read = meson_rng_read,
|
|
};
|
|
|
|
static const struct udevice_id meson_rng_match[] = {
|
|
{
|
|
.compatible = "amlogic,meson-rng",
|
|
},
|
|
{},
|
|
};
|
|
|
|
U_BOOT_DRIVER(meson_rng) = {
|
|
.name = "meson-rng",
|
|
.id = UCLASS_RNG,
|
|
.of_match = meson_rng_match,
|
|
.ops = &meson_rng_ops,
|
|
.probe = meson_rng_probe,
|
|
.remove = meson_rng_remove,
|
|
.plat_auto = sizeof(struct meson_rng_plat),
|
|
.of_to_plat = meson_rng_of_to_plat,
|
|
};
|