115 lines
2.7 KiB
C
115 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Oxford Semiconductor Reset Controller driver
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*
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* Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
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* Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
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* Copyright (C) 2009 Oxford Semiconductor Ltd
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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/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/delay.h>
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#include <linux/types.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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/* Regmap offsets */
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#define RST_SET_REGOFFSET 0x34
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#define RST_CLR_REGOFFSET 0x38
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struct oxnas_reset {
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struct regmap *regmap;
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struct reset_controller_dev rcdev;
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};
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static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct oxnas_reset *data =
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container_of(rcdev, struct oxnas_reset, rcdev);
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regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
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msleep(50);
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regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
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return 0;
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}
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static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct oxnas_reset *data =
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container_of(rcdev, struct oxnas_reset, rcdev);
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regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
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return 0;
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}
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static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct oxnas_reset *data =
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container_of(rcdev, struct oxnas_reset, rcdev);
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regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
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return 0;
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}
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static const struct reset_control_ops oxnas_reset_ops = {
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.reset = oxnas_reset_reset,
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.assert = oxnas_reset_assert,
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.deassert = oxnas_reset_deassert,
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};
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static const struct of_device_id oxnas_reset_dt_ids[] = {
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{ .compatible = "oxsemi,ox810se-reset", },
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{ .compatible = "oxsemi,ox820-reset", },
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{ /* sentinel */ },
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};
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static int oxnas_reset_probe(struct platform_device *pdev)
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{
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struct oxnas_reset *data;
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struct device *parent;
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parent = pdev->dev.parent;
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if (!parent) {
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dev_err(&pdev->dev, "no parent\n");
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return -ENODEV;
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}
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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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data->regmap = syscon_node_to_regmap(parent->of_node);
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if (IS_ERR(data->regmap)) {
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dev_err(&pdev->dev, "failed to get parent regmap\n");
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return PTR_ERR(data->regmap);
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}
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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 = 32;
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data->rcdev.ops = &oxnas_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 oxnas_reset_driver = {
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.probe = oxnas_reset_probe,
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.driver = {
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.name = "oxnas-reset",
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.of_match_table = oxnas_reset_dt_ids,
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},
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};
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builtin_platform_driver(oxnas_reset_driver);
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