154 lines
3.9 KiB
C
154 lines
3.9 KiB
C
/*
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* Socfpga Reset Controller Driver
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*
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* Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
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*
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* based on
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* Allwinner SoCs Reset Controller driver
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*
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* Copyright 2013 Maxime Ripard
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*
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* Maxime Ripard <maxime.ripard@free-electrons.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; either version 2 of the License, or
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* (at your option) any later version.
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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/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/spinlock.h>
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#include <linux/types.h>
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#define NR_BANKS 4
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struct socfpga_reset_data {
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spinlock_t lock;
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void __iomem *membase;
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struct reset_controller_dev rcdev;
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};
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static int socfpga_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct socfpga_reset_data *data = container_of(rcdev,
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struct socfpga_reset_data,
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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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unsigned long flags;
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u32 reg;
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spin_lock_irqsave(&data->lock, flags);
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reg = readl(data->membase + (bank * NR_BANKS));
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writel(reg | BIT(offset), data->membase + (bank * NR_BANKS));
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spin_unlock_irqrestore(&data->lock, flags);
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return 0;
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}
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static int socfpga_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct socfpga_reset_data *data = container_of(rcdev,
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struct socfpga_reset_data,
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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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unsigned long flags;
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u32 reg;
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spin_lock_irqsave(&data->lock, flags);
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reg = readl(data->membase + (bank * NR_BANKS));
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writel(reg & ~BIT(offset), data->membase + (bank * NR_BANKS));
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spin_unlock_irqrestore(&data->lock, flags);
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return 0;
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}
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static int socfpga_reset_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct socfpga_reset_data *data = container_of(rcdev,
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struct socfpga_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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u32 reg;
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reg = readl(data->membase + (bank * NR_BANKS));
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return !(reg & BIT(offset));
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}
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static const struct reset_control_ops socfpga_reset_ops = {
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.assert = socfpga_reset_assert,
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.deassert = socfpga_reset_deassert,
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.status = socfpga_reset_status,
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};
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static int socfpga_reset_probe(struct platform_device *pdev)
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{
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struct socfpga_reset_data *data;
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struct resource *res;
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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u32 modrst_offset;
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/*
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* The binding was mainlined without the required property.
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* Do not continue, when we encounter an old DT.
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*/
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if (!of_find_property(pdev->dev.of_node, "#reset-cells", NULL)) {
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dev_err(&pdev->dev, "%s missing #reset-cells property\n",
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pdev->dev.of_node->full_name);
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return -EINVAL;
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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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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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data->membase = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(data->membase))
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return PTR_ERR(data->membase);
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if (of_property_read_u32(np, "altr,modrst-offset", &modrst_offset)) {
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dev_warn(dev, "missing altr,modrst-offset property, assuming 0x10!\n");
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modrst_offset = 0x10;
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}
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data->membase += modrst_offset;
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spin_lock_init(&data->lock);
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data->rcdev.owner = THIS_MODULE;
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data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG;
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data->rcdev.ops = &socfpga_reset_ops;
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data->rcdev.of_node = pdev->dev.of_node;
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return devm_reset_controller_register(dev, &data->rcdev);
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}
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static const struct of_device_id socfpga_reset_dt_ids[] = {
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{ .compatible = "altr,rst-mgr", },
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{ /* sentinel */ },
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};
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static struct platform_driver socfpga_reset_driver = {
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.probe = socfpga_reset_probe,
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.driver = {
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.name = "socfpga-reset",
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.of_match_table = socfpga_reset_dt_ids,
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},
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};
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builtin_platform_driver(socfpga_reset_driver);
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