| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Mediatek Watchdog Driver |
| * |
| * Copyright (C) 2014 Matthias Brugger |
| * |
| * Matthias Brugger <matthias.bgg@gmail.com> |
| * |
| * Based on sunxi_wdt.c |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/init.h> |
| #include <linux/io.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/of.h> |
| #include <linux/platform_device.h> |
| #include <linux/types.h> |
| #include <linux/watchdog.h> |
| #include <linux/delay.h> |
| |
| #define WDT_MAX_TIMEOUT 31 |
| #define WDT_MIN_TIMEOUT 1 |
| #define WDT_LENGTH_TIMEOUT(n) ((n) << 5) |
| |
| #define WDT_LENGTH 0x04 |
| #define WDT_LENGTH_KEY 0x8 |
| |
| #define WDT_RST 0x08 |
| #define WDT_RST_RELOAD 0x1971 |
| |
| #define WDT_MODE 0x00 |
| #define WDT_MODE_EN (1 << 0) |
| #define WDT_MODE_EXT_POL_LOW (0 << 1) |
| #define WDT_MODE_EXT_POL_HIGH (1 << 1) |
| #define WDT_MODE_EXRST_EN (1 << 2) |
| #define WDT_MODE_IRQ_EN (1 << 3) |
| #define WDT_MODE_AUTO_START (1 << 4) |
| #define WDT_MODE_DUAL_EN (1 << 6) |
| #define WDT_MODE_KEY 0x22000000 |
| |
| #define WDT_SWRST 0x14 |
| #define WDT_SWRST_KEY 0x1209 |
| |
| #define DRV_NAME "mtk-wdt" |
| #define DRV_VERSION "1.0" |
| |
| static bool nowayout = WATCHDOG_NOWAYOUT; |
| static unsigned int timeout; |
| |
| struct mtk_wdt_dev { |
| struct watchdog_device wdt_dev; |
| void __iomem *wdt_base; |
| }; |
| |
| static int mtk_wdt_restart(struct watchdog_device *wdt_dev, |
| unsigned long action, void *data) |
| { |
| struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); |
| void __iomem *wdt_base; |
| |
| wdt_base = mtk_wdt->wdt_base; |
| |
| while (1) { |
| writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST); |
| mdelay(5); |
| } |
| |
| return 0; |
| } |
| |
| static int mtk_wdt_ping(struct watchdog_device *wdt_dev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); |
| void __iomem *wdt_base = mtk_wdt->wdt_base; |
| |
| iowrite32(WDT_RST_RELOAD, wdt_base + WDT_RST); |
| |
| return 0; |
| } |
| |
| static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| unsigned int timeout) |
| { |
| struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); |
| void __iomem *wdt_base = mtk_wdt->wdt_base; |
| u32 reg; |
| |
| wdt_dev->timeout = timeout; |
| |
| /* |
| * One bit is the value of 512 ticks |
| * The clock has 32 KHz |
| */ |
| reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY; |
| iowrite32(reg, wdt_base + WDT_LENGTH); |
| |
| mtk_wdt_ping(wdt_dev); |
| |
| return 0; |
| } |
| |
| static int mtk_wdt_stop(struct watchdog_device *wdt_dev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); |
| void __iomem *wdt_base = mtk_wdt->wdt_base; |
| u32 reg; |
| |
| reg = readl(wdt_base + WDT_MODE); |
| reg &= ~WDT_MODE_EN; |
| reg |= WDT_MODE_KEY; |
| iowrite32(reg, wdt_base + WDT_MODE); |
| |
| return 0; |
| } |
| |
| static int mtk_wdt_start(struct watchdog_device *wdt_dev) |
| { |
| u32 reg; |
| struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); |
| void __iomem *wdt_base = mtk_wdt->wdt_base; |
| int ret; |
| |
| ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout); |
| if (ret < 0) |
| return ret; |
| |
| reg = ioread32(wdt_base + WDT_MODE); |
| reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN); |
| reg |= (WDT_MODE_EN | WDT_MODE_KEY); |
| iowrite32(reg, wdt_base + WDT_MODE); |
| |
| return 0; |
| } |
| |
| static const struct watchdog_info mtk_wdt_info = { |
| .identity = DRV_NAME, |
| .options = WDIOF_SETTIMEOUT | |
| WDIOF_KEEPALIVEPING | |
| WDIOF_MAGICCLOSE, |
| }; |
| |
| static const struct watchdog_ops mtk_wdt_ops = { |
| .owner = THIS_MODULE, |
| .start = mtk_wdt_start, |
| .stop = mtk_wdt_stop, |
| .ping = mtk_wdt_ping, |
| .set_timeout = mtk_wdt_set_timeout, |
| .restart = mtk_wdt_restart, |
| }; |
| |
| static int mtk_wdt_probe(struct platform_device *pdev) |
| { |
| struct mtk_wdt_dev *mtk_wdt; |
| struct resource *res; |
| int err; |
| |
| mtk_wdt = devm_kzalloc(&pdev->dev, sizeof(*mtk_wdt), GFP_KERNEL); |
| if (!mtk_wdt) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, mtk_wdt); |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(mtk_wdt->wdt_base)) |
| return PTR_ERR(mtk_wdt->wdt_base); |
| |
| mtk_wdt->wdt_dev.info = &mtk_wdt_info; |
| mtk_wdt->wdt_dev.ops = &mtk_wdt_ops; |
| mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT; |
| mtk_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT; |
| mtk_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT; |
| mtk_wdt->wdt_dev.parent = &pdev->dev; |
| |
| watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, &pdev->dev); |
| watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout); |
| watchdog_set_restart_priority(&mtk_wdt->wdt_dev, 128); |
| |
| watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt); |
| |
| mtk_wdt_stop(&mtk_wdt->wdt_dev); |
| |
| err = watchdog_register_device(&mtk_wdt->wdt_dev); |
| if (unlikely(err)) |
| return err; |
| |
| dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n", |
| mtk_wdt->wdt_dev.timeout, nowayout); |
| |
| return 0; |
| } |
| |
| static void mtk_wdt_shutdown(struct platform_device *pdev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev); |
| |
| if (watchdog_active(&mtk_wdt->wdt_dev)) |
| mtk_wdt_stop(&mtk_wdt->wdt_dev); |
| } |
| |
| static int mtk_wdt_remove(struct platform_device *pdev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev); |
| |
| watchdog_unregister_device(&mtk_wdt->wdt_dev); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int mtk_wdt_suspend(struct device *dev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = dev_get_drvdata(dev); |
| |
| if (watchdog_active(&mtk_wdt->wdt_dev)) |
| mtk_wdt_stop(&mtk_wdt->wdt_dev); |
| |
| return 0; |
| } |
| |
| static int mtk_wdt_resume(struct device *dev) |
| { |
| struct mtk_wdt_dev *mtk_wdt = dev_get_drvdata(dev); |
| |
| if (watchdog_active(&mtk_wdt->wdt_dev)) { |
| mtk_wdt_start(&mtk_wdt->wdt_dev); |
| mtk_wdt_ping(&mtk_wdt->wdt_dev); |
| } |
| |
| return 0; |
| } |
| #endif |
| |
| static const struct of_device_id mtk_wdt_dt_ids[] = { |
| { .compatible = "mediatek,mt6589-wdt" }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids); |
| |
| static const struct dev_pm_ops mtk_wdt_pm_ops = { |
| SET_SYSTEM_SLEEP_PM_OPS(mtk_wdt_suspend, |
| mtk_wdt_resume) |
| }; |
| |
| static struct platform_driver mtk_wdt_driver = { |
| .probe = mtk_wdt_probe, |
| .remove = mtk_wdt_remove, |
| .shutdown = mtk_wdt_shutdown, |
| .driver = { |
| .name = DRV_NAME, |
| .pm = &mtk_wdt_pm_ops, |
| .of_match_table = mtk_wdt_dt_ids, |
| }, |
| }; |
| |
| module_platform_driver(mtk_wdt_driver); |
| |
| module_param(timeout, uint, 0); |
| MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); |
| |
| module_param(nowayout, bool, 0); |
| MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
| __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Matthias Brugger <matthias.bgg@gmail.com>"); |
| MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver"); |
| MODULE_VERSION(DRV_VERSION); |