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41575d8e4c
This construct is quite long-winded. In earlier days it made some sense since auto-allocation was a strange concept. But with driver model now used pretty universally, we can shorten this to 'auto'. This reduces verbosity and makes it easier to read. Coincidentally it also ensures that every declaration is on one line, thus making dtoc's job easier. Signed-off-by: Simon Glass <sjg@chromium.org>
121 lines
2.2 KiB
C
121 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
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*
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* Driver for Amlogic hardware random number generator
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*/
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#include <common.h>
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#include <clk.h>
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#include <dm.h>
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#include <rng.h>
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#include <asm/io.h>
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struct meson_rng_platdata {
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fdt_addr_t base;
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struct clk clk;
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};
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/**
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* meson_rng_read() - fill buffer with random bytes
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*
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* @buffer: buffer to receive data
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* @size: size of buffer
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*
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* Return: 0
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*/
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static int meson_rng_read(struct udevice *dev, void *data, size_t len)
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{
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struct meson_rng_platdata *pdata = dev_get_platdata(dev);
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char *buffer = (char *)data;
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while (len) {
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u32 rand = readl(pdata->base);
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size_t step;
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if (len >= 4)
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step = 4;
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else
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step = len;
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memcpy(buffer, &rand, step);
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buffer += step;
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len -= step;
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}
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return 0;
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}
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/**
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* meson_rng_probe() - probe rng device
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*
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* @dev: device
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* Return: 0 if ok
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*/
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static int meson_rng_probe(struct udevice *dev)
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{
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struct meson_rng_platdata *pdata = dev_get_platdata(dev);
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int err;
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err = clk_enable(&pdata->clk);
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if (err)
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return err;
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return 0;
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}
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/**
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* meson_rng_remove() - deinitialize rng device
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*
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* @dev: device
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* Return: 0 if ok
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*/
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static int meson_rng_remove(struct udevice *dev)
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{
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struct meson_rng_platdata *pdata = dev_get_platdata(dev);
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return clk_disable(&pdata->clk);
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}
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/**
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* meson_rng_ofdata_to_platdata() - transfer device tree data to plaform data
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*
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* @dev: device
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* Return: 0 if ok
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*/
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static int meson_rng_ofdata_to_platdata(struct udevice *dev)
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{
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struct meson_rng_platdata *pdata = dev_get_platdata(dev);
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int err;
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pdata->base = dev_read_addr(dev);
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if (!pdata->base)
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return -ENODEV;
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/* Get optional "core" clock */
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err = clk_get_by_name(dev, "core", &pdata->clk);
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if (err && err != -ENODATA)
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return err;
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return 0;
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}
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static const struct dm_rng_ops meson_rng_ops = {
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.read = meson_rng_read,
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};
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static const struct udevice_id meson_rng_match[] = {
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{
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.compatible = "amlogic,meson-rng",
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},
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{},
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};
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U_BOOT_DRIVER(meson_rng) = {
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.name = "meson-rng",
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.id = UCLASS_RNG,
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.of_match = meson_rng_match,
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.ops = &meson_rng_ops,
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.probe = meson_rng_probe,
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.remove = meson_rng_remove,
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.platdata_auto = sizeof(struct meson_rng_platdata),
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.ofdata_to_platdata = meson_rng_ofdata_to_platdata,
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};
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