| /* |
| * Copyright (C) 2015 Alban Bedel <albeu@free.fr> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/reset-controller.h> |
| #include <linux/reboot.h> |
| |
| struct ath79_reset { |
| struct reset_controller_dev rcdev; |
| struct notifier_block restart_nb; |
| void __iomem *base; |
| spinlock_t lock; |
| }; |
| |
| #define FULL_CHIP_RESET 24 |
| |
| static int ath79_reset_update(struct reset_controller_dev *rcdev, |
| unsigned long id, bool assert) |
| { |
| struct ath79_reset *ath79_reset = |
| container_of(rcdev, struct ath79_reset, rcdev); |
| unsigned long flags; |
| u32 val; |
| |
| spin_lock_irqsave(&ath79_reset->lock, flags); |
| val = readl(ath79_reset->base); |
| if (assert) |
| val |= BIT(id); |
| else |
| val &= ~BIT(id); |
| writel(val, ath79_reset->base); |
| spin_unlock_irqrestore(&ath79_reset->lock, flags); |
| |
| return 0; |
| } |
| |
| static int ath79_reset_assert(struct reset_controller_dev *rcdev, |
| unsigned long id) |
| { |
| return ath79_reset_update(rcdev, id, true); |
| } |
| |
| static int ath79_reset_deassert(struct reset_controller_dev *rcdev, |
| unsigned long id) |
| { |
| return ath79_reset_update(rcdev, id, false); |
| } |
| |
| static int ath79_reset_status(struct reset_controller_dev *rcdev, |
| unsigned long id) |
| { |
| struct ath79_reset *ath79_reset = |
| container_of(rcdev, struct ath79_reset, rcdev); |
| u32 val; |
| |
| val = readl(ath79_reset->base); |
| |
| return !!(val & BIT(id)); |
| } |
| |
| static const struct reset_control_ops ath79_reset_ops = { |
| .assert = ath79_reset_assert, |
| .deassert = ath79_reset_deassert, |
| .status = ath79_reset_status, |
| }; |
| |
| static int ath79_reset_restart_handler(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| struct ath79_reset *ath79_reset = |
| container_of(nb, struct ath79_reset, restart_nb); |
| |
| ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET); |
| |
| return NOTIFY_DONE; |
| } |
| |
| static int ath79_reset_probe(struct platform_device *pdev) |
| { |
| struct ath79_reset *ath79_reset; |
| struct resource *res; |
| int err; |
| |
| ath79_reset = devm_kzalloc(&pdev->dev, |
| sizeof(*ath79_reset), GFP_KERNEL); |
| if (!ath79_reset) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, ath79_reset); |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| ath79_reset->base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(ath79_reset->base)) |
| return PTR_ERR(ath79_reset->base); |
| |
| spin_lock_init(&ath79_reset->lock); |
| ath79_reset->rcdev.ops = &ath79_reset_ops; |
| ath79_reset->rcdev.owner = THIS_MODULE; |
| ath79_reset->rcdev.of_node = pdev->dev.of_node; |
| ath79_reset->rcdev.of_reset_n_cells = 1; |
| ath79_reset->rcdev.nr_resets = 32; |
| |
| err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev); |
| if (err) |
| return err; |
| |
| ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler; |
| ath79_reset->restart_nb.priority = 128; |
| |
| err = register_restart_handler(&ath79_reset->restart_nb); |
| if (err) |
| dev_warn(&pdev->dev, "Failed to register restart handler\n"); |
| |
| return 0; |
| } |
| |
| static int ath79_reset_remove(struct platform_device *pdev) |
| { |
| struct ath79_reset *ath79_reset = platform_get_drvdata(pdev); |
| |
| unregister_restart_handler(&ath79_reset->restart_nb); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id ath79_reset_dt_ids[] = { |
| { .compatible = "qca,ar7100-reset", }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids); |
| |
| static struct platform_driver ath79_reset_driver = { |
| .probe = ath79_reset_probe, |
| .remove = ath79_reset_remove, |
| .driver = { |
| .name = "ath79-reset", |
| .of_match_table = ath79_reset_dt_ids, |
| }, |
| }; |
| module_platform_driver(ath79_reset_driver); |
| |
| MODULE_AUTHOR("Alban Bedel <albeu@free.fr>"); |
| MODULE_DESCRIPTION("AR71xx Reset Controller Driver"); |
| MODULE_LICENSE("GPL"); |