133 lines
4.4 KiB
C
133 lines
4.4 KiB
C
/*
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* Amlogic Meson Reset Controller driver
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*
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* This file is provided under a dual BSD/GPLv2 license. When using or
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* redistributing this file, you may do so under either license.
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*
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* GPL LICENSE SUMMARY
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*
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* Copyright (c) 2016 BayLibre, SAS.
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* Author: Neil Armstrong <narmstrong@baylibre.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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* The full GNU General Public License is included in this distribution
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* in the file called COPYING.
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*
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* BSD LICENSE
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*
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* Copyright (c) 2016 BayLibre, SAS.
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* Author: Neil Armstrong <narmstrong@baylibre.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/reset-controller.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#define REG_COUNT 8
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#define BITS_PER_REG 32
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struct meson_reset {
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void __iomem *reg_base;
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struct reset_controller_dev rcdev;
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};
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static int meson_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct meson_reset *data =
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container_of(rcdev, struct meson_reset, rcdev);
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unsigned int bank = id / BITS_PER_REG;
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unsigned int offset = id % BITS_PER_REG;
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void __iomem *reg_addr = data->reg_base + (bank << 2);
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if (bank >= REG_COUNT)
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return -EINVAL;
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writel(BIT(offset), reg_addr);
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return 0;
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}
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static const struct reset_control_ops meson_reset_ops = {
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.reset = meson_reset_reset,
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};
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static const struct of_device_id meson_reset_dt_ids[] = {
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{ .compatible = "amlogic,meson8b-reset", },
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{ .compatible = "amlogic,meson-gxbb-reset", },
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{ /* sentinel */ },
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};
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static int meson_reset_probe(struct platform_device *pdev)
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{
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struct meson_reset *data;
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struct resource *res;
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data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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data->reg_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(data->reg_base))
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return PTR_ERR(data->reg_base);
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platform_set_drvdata(pdev, data);
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data->rcdev.owner = THIS_MODULE;
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data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG;
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data->rcdev.ops = &meson_reset_ops;
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data->rcdev.of_node = pdev->dev.of_node;
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return devm_reset_controller_register(&pdev->dev, &data->rcdev);
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}
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static struct platform_driver meson_reset_driver = {
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.probe = meson_reset_probe,
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.driver = {
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.name = "meson_reset",
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.of_match_table = meson_reset_dt_ids,
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},
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};
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builtin_platform_driver(meson_reset_driver);
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