143 lines
3.6 KiB
C
143 lines
3.6 KiB
C
/*
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* Copyright (c) 2015, National Instruments Corp.
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*
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* Xilinx Zynq Reset controller driver
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*
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* Author: Moritz Fischer <moritz.fischer@ettus.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 the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/init.h>
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#include <linux/mfd/syscon.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/regmap.h>
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#include <linux/types.h>
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struct zynq_reset_data {
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struct regmap *slcr;
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struct reset_controller_dev rcdev;
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u32 offset;
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};
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#define to_zynq_reset_data(p) \
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container_of((p), struct zynq_reset_data, rcdev)
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static int zynq_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
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int bank = id / BITS_PER_LONG;
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int offset = id % BITS_PER_LONG;
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pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
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bank, offset);
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return regmap_update_bits(priv->slcr,
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priv->offset + (bank * 4),
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BIT(offset),
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BIT(offset));
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}
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static int zynq_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
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int bank = id / BITS_PER_LONG;
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int offset = id % BITS_PER_LONG;
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pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
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bank, offset);
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return regmap_update_bits(priv->slcr,
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priv->offset + (bank * 4),
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BIT(offset),
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~BIT(offset));
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}
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static int zynq_reset_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
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int bank = id / BITS_PER_LONG;
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int offset = id % BITS_PER_LONG;
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int ret;
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u32 reg;
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pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
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bank, offset);
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ret = regmap_read(priv->slcr, priv->offset + (bank * 4), ®);
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if (ret)
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return ret;
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return !!(reg & BIT(offset));
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}
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static const struct reset_control_ops zynq_reset_ops = {
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.assert = zynq_reset_assert,
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.deassert = zynq_reset_deassert,
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.status = zynq_reset_status,
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};
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static int zynq_reset_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct zynq_reset_data *priv;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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platform_set_drvdata(pdev, priv);
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priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
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"syscon");
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if (IS_ERR(priv->slcr)) {
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dev_err(&pdev->dev, "unable to get zynq-slcr regmap");
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return PTR_ERR(priv->slcr);
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "missing IO resource\n");
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return -ENODEV;
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}
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priv->offset = res->start;
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priv->rcdev.owner = THIS_MODULE;
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priv->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_LONG;
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priv->rcdev.ops = &zynq_reset_ops;
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priv->rcdev.of_node = pdev->dev.of_node;
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return devm_reset_controller_register(&pdev->dev, &priv->rcdev);
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}
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static const struct of_device_id zynq_reset_dt_ids[] = {
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{ .compatible = "xlnx,zynq-reset", },
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{ /* sentinel */ },
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};
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static struct platform_driver zynq_reset_driver = {
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.probe = zynq_reset_probe,
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.driver = {
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.name = KBUILD_MODNAME,
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.of_match_table = zynq_reset_dt_ids,
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},
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};
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builtin_platform_driver(zynq_reset_driver);
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