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![Pali Rohár](/assets/img/avatar_default.png)
For security reasons I stopped using gmail account and kernel address is now up-to-date alias to my personal address. People periodically send me emails to address which they found in source code of drivers, so this change reflects state where people can contact me. [ Added .mailmap entry as per Joe Perches - Linus ] Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
182 lines
4 KiB
C
182 lines
4 KiB
C
/*
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* omap3-rom-rng.c - RNG driver for TI OMAP3 CPU family
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*
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* Copyright (C) 2009 Nokia Corporation
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* Author: Juha Yrjola <juha.yrjola@solidboot.com>
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*
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* Copyright (C) 2013 Pali Rohár <pali@kernel.org>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/random.h>
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#include <linux/hw_random.h>
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#include <linux/workqueue.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#define RNG_RESET 0x01
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#define RNG_GEN_PRNG_HW_INIT 0x02
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#define RNG_GEN_HW 0x08
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struct omap_rom_rng {
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struct clk *clk;
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struct device *dev;
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struct hwrng ops;
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u32 (*rom_rng_call)(u32 ptr, u32 count, u32 flag);
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};
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static int omap3_rom_rng_read(struct hwrng *rng, void *data, size_t max, bool w)
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{
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struct omap_rom_rng *ddata;
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u32 ptr;
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int r;
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ddata = (struct omap_rom_rng *)rng->priv;
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r = pm_runtime_get_sync(ddata->dev);
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if (r < 0) {
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pm_runtime_put_noidle(ddata->dev);
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return r;
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}
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ptr = virt_to_phys(data);
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r = ddata->rom_rng_call(ptr, 4, RNG_GEN_HW);
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if (r != 0)
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r = -EINVAL;
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else
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r = 4;
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pm_runtime_mark_last_busy(ddata->dev);
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pm_runtime_put_autosuspend(ddata->dev);
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return r;
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}
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static int __maybe_unused omap_rom_rng_runtime_suspend(struct device *dev)
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{
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struct omap_rom_rng *ddata;
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int r;
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ddata = dev_get_drvdata(dev);
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r = ddata->rom_rng_call(0, 0, RNG_RESET);
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if (r != 0)
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dev_err(dev, "reset failed: %d\n", r);
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clk_disable_unprepare(ddata->clk);
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return 0;
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}
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static int __maybe_unused omap_rom_rng_runtime_resume(struct device *dev)
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{
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struct omap_rom_rng *ddata;
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int r;
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ddata = dev_get_drvdata(dev);
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r = clk_prepare_enable(ddata->clk);
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if (r < 0)
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return r;
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r = ddata->rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
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if (r != 0) {
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clk_disable(ddata->clk);
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dev_err(dev, "HW init failed: %d\n", r);
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return -EIO;
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}
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return 0;
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}
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static void omap_rom_rng_finish(void *data)
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{
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struct omap_rom_rng *ddata = data;
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pm_runtime_dont_use_autosuspend(ddata->dev);
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pm_runtime_disable(ddata->dev);
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}
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static int omap3_rom_rng_probe(struct platform_device *pdev)
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{
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struct omap_rom_rng *ddata;
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int ret = 0;
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ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
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if (!ddata)
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return -ENOMEM;
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ddata->dev = &pdev->dev;
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ddata->ops.priv = (unsigned long)ddata;
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ddata->ops.name = "omap3-rom";
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ddata->ops.read = of_device_get_match_data(&pdev->dev);
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ddata->ops.quality = 900;
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if (!ddata->ops.read) {
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dev_err(&pdev->dev, "missing rom code handler\n");
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return -ENODEV;
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}
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dev_set_drvdata(ddata->dev, ddata);
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ddata->rom_rng_call = pdev->dev.platform_data;
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if (!ddata->rom_rng_call) {
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dev_err(ddata->dev, "rom_rng_call is NULL\n");
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return -EINVAL;
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}
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ddata->clk = devm_clk_get(ddata->dev, "ick");
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if (IS_ERR(ddata->clk)) {
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dev_err(ddata->dev, "unable to get RNG clock\n");
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return PTR_ERR(ddata->clk);
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}
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pm_runtime_enable(&pdev->dev);
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pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
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pm_runtime_use_autosuspend(&pdev->dev);
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ret = devm_add_action_or_reset(ddata->dev, omap_rom_rng_finish,
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ddata);
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if (ret)
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return ret;
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return devm_hwrng_register(ddata->dev, &ddata->ops);
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}
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static const struct of_device_id omap_rom_rng_match[] = {
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{ .compatible = "nokia,n900-rom-rng", .data = omap3_rom_rng_read, },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, omap_rom_rng_match);
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static const struct dev_pm_ops omap_rom_rng_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(omap_rom_rng_runtime_suspend,
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omap_rom_rng_runtime_resume)
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};
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static struct platform_driver omap3_rom_rng_driver = {
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.driver = {
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.name = "omap3-rom-rng",
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.of_match_table = omap_rom_rng_match,
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.pm = &omap_rom_rng_pm_ops,
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},
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.probe = omap3_rom_rng_probe,
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};
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module_platform_driver(omap3_rom_rng_driver);
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MODULE_ALIAS("platform:omap3-rom-rng");
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MODULE_AUTHOR("Juha Yrjola");
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MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
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MODULE_LICENSE("GPL");
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