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138 lines
3.3 KiB
138 lines
3.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* AR71xx Reset Controller Driver |
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* Author: Alban Bedel |
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* |
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* Copyright (C) 2015 Alban Bedel <[email protected]> |
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*/ |
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#include <linux/io.h> |
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#include <linux/init.h> |
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#include <linux/mod_devicetable.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/reboot.h> |
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struct ath79_reset { |
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struct reset_controller_dev rcdev; |
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struct notifier_block restart_nb; |
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void __iomem *base; |
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spinlock_t lock; |
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}; |
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#define FULL_CHIP_RESET 24 |
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static int ath79_reset_update(struct reset_controller_dev *rcdev, |
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unsigned long id, bool assert) |
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{ |
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struct ath79_reset *ath79_reset = |
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container_of(rcdev, struct ath79_reset, rcdev); |
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unsigned long flags; |
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u32 val; |
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spin_lock_irqsave(&ath79_reset->lock, flags); |
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val = readl(ath79_reset->base); |
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if (assert) |
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val |= BIT(id); |
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else |
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val &= ~BIT(id); |
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writel(val, ath79_reset->base); |
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spin_unlock_irqrestore(&ath79_reset->lock, flags); |
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return 0; |
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} |
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static int ath79_reset_assert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return ath79_reset_update(rcdev, id, true); |
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} |
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static int ath79_reset_deassert(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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return ath79_reset_update(rcdev, id, false); |
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} |
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static int ath79_reset_status(struct reset_controller_dev *rcdev, |
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unsigned long id) |
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{ |
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struct ath79_reset *ath79_reset = |
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container_of(rcdev, struct ath79_reset, rcdev); |
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u32 val; |
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val = readl(ath79_reset->base); |
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return !!(val & BIT(id)); |
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} |
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static const struct reset_control_ops ath79_reset_ops = { |
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.assert = ath79_reset_assert, |
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.deassert = ath79_reset_deassert, |
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.status = ath79_reset_status, |
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}; |
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static int ath79_reset_restart_handler(struct notifier_block *nb, |
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unsigned long action, void *data) |
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{ |
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struct ath79_reset *ath79_reset = |
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container_of(nb, struct ath79_reset, restart_nb); |
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ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET); |
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return NOTIFY_DONE; |
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} |
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static int ath79_reset_probe(struct platform_device *pdev) |
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{ |
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struct ath79_reset *ath79_reset; |
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struct resource *res; |
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int err; |
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ath79_reset = devm_kzalloc(&pdev->dev, |
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sizeof(*ath79_reset), GFP_KERNEL); |
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if (!ath79_reset) |
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return -ENOMEM; |
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platform_set_drvdata(pdev, ath79_reset); |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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ath79_reset->base = devm_ioremap_resource(&pdev->dev, res); |
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if (IS_ERR(ath79_reset->base)) |
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return PTR_ERR(ath79_reset->base); |
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spin_lock_init(&ath79_reset->lock); |
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ath79_reset->rcdev.ops = &ath79_reset_ops; |
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ath79_reset->rcdev.owner = THIS_MODULE; |
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ath79_reset->rcdev.of_node = pdev->dev.of_node; |
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ath79_reset->rcdev.of_reset_n_cells = 1; |
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ath79_reset->rcdev.nr_resets = 32; |
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err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev); |
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if (err) |
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return err; |
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ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler; |
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ath79_reset->restart_nb.priority = 128; |
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err = register_restart_handler(&ath79_reset->restart_nb); |
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if (err) |
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dev_warn(&pdev->dev, "Failed to register restart handler\n"); |
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return 0; |
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} |
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static const struct of_device_id ath79_reset_dt_ids[] = { |
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{ .compatible = "qca,ar7100-reset", }, |
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{ }, |
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}; |
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static struct platform_driver ath79_reset_driver = { |
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.probe = ath79_reset_probe, |
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.driver = { |
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.name = "ath79-reset", |
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.of_match_table = ath79_reset_dt_ids, |
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.suppress_bind_attrs = true, |
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}, |
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}; |
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builtin_platform_driver(ath79_reset_driver);
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