1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * AR71xx Reset Controller Driver
6 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
10 #include <linux/init.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/platform_device.h>
13 #include <linux/reset-controller.h>
14 #include <linux/reboot.h>
17 struct reset_controller_dev rcdev;
18 struct notifier_block restart_nb;
23 #define FULL_CHIP_RESET 24
25 static int ath79_reset_update(struct reset_controller_dev *rcdev,
26 unsigned long id, bool assert)
28 struct ath79_reset *ath79_reset =
29 container_of(rcdev, struct ath79_reset, rcdev);
33 spin_lock_irqsave(&ath79_reset->lock, flags);
34 val = readl(ath79_reset->base);
39 writel(val, ath79_reset->base);
40 spin_unlock_irqrestore(&ath79_reset->lock, flags);
45 static int ath79_reset_assert(struct reset_controller_dev *rcdev,
48 return ath79_reset_update(rcdev, id, true);
51 static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
54 return ath79_reset_update(rcdev, id, false);
57 static int ath79_reset_status(struct reset_controller_dev *rcdev,
60 struct ath79_reset *ath79_reset =
61 container_of(rcdev, struct ath79_reset, rcdev);
64 val = readl(ath79_reset->base);
66 return !!(val & BIT(id));
69 static const struct reset_control_ops ath79_reset_ops = {
70 .assert = ath79_reset_assert,
71 .deassert = ath79_reset_deassert,
72 .status = ath79_reset_status,
75 static int ath79_reset_restart_handler(struct notifier_block *nb,
76 unsigned long action, void *data)
78 struct ath79_reset *ath79_reset =
79 container_of(nb, struct ath79_reset, restart_nb);
81 ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
86 static int ath79_reset_probe(struct platform_device *pdev)
88 struct ath79_reset *ath79_reset;
91 ath79_reset = devm_kzalloc(&pdev->dev,
92 sizeof(*ath79_reset), GFP_KERNEL);
96 platform_set_drvdata(pdev, ath79_reset);
98 ath79_reset->base = devm_platform_ioremap_resource(pdev, 0);
99 if (IS_ERR(ath79_reset->base))
100 return PTR_ERR(ath79_reset->base);
102 spin_lock_init(&ath79_reset->lock);
103 ath79_reset->rcdev.ops = &ath79_reset_ops;
104 ath79_reset->rcdev.owner = THIS_MODULE;
105 ath79_reset->rcdev.of_node = pdev->dev.of_node;
106 ath79_reset->rcdev.of_reset_n_cells = 1;
107 ath79_reset->rcdev.nr_resets = 32;
109 err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
113 ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
114 ath79_reset->restart_nb.priority = 128;
116 err = register_restart_handler(&ath79_reset->restart_nb);
118 dev_warn(&pdev->dev, "Failed to register restart handler\n");
123 static const struct of_device_id ath79_reset_dt_ids[] = {
124 { .compatible = "qca,ar7100-reset", },
128 static struct platform_driver ath79_reset_driver = {
129 .probe = ath79_reset_probe,
131 .name = "ath79-reset",
132 .of_match_table = ath79_reset_dt_ids,
133 .suppress_bind_attrs = true,
136 builtin_platform_driver(ath79_reset_driver);