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226 lines
5.7 KiB
226 lines
5.7 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Meson Watchdog Driver |
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* |
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* Copyright (c) 2014 Carlo Caione |
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*/ |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/err.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/platform_device.h> |
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#include <linux/types.h> |
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#include <linux/watchdog.h> |
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#define DRV_NAME "meson_wdt" |
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#define MESON_WDT_TC 0x00 |
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#define MESON_WDT_DC_RESET (3 << 24) |
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#define MESON_WDT_RESET 0x04 |
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#define MESON_WDT_TIMEOUT 30 |
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#define MESON_WDT_MIN_TIMEOUT 1 |
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#define MESON_SEC_TO_TC(s, c) ((s) * (c)) |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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static unsigned int timeout; |
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struct meson_wdt_data { |
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unsigned int enable; |
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unsigned int terminal_count_mask; |
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unsigned int count_unit; |
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}; |
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static struct meson_wdt_data meson6_wdt_data = { |
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.enable = BIT(22), |
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.terminal_count_mask = 0x3fffff, |
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.count_unit = 100000, /* 10 us */ |
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}; |
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static struct meson_wdt_data meson8b_wdt_data = { |
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.enable = BIT(19), |
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.terminal_count_mask = 0xffff, |
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.count_unit = 7812, /* 128 us */ |
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}; |
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struct meson_wdt_dev { |
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struct watchdog_device wdt_dev; |
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void __iomem *wdt_base; |
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const struct meson_wdt_data *data; |
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}; |
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static int meson_wdt_restart(struct watchdog_device *wdt_dev, |
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unsigned long action, void *data) |
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{ |
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struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
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u32 tc_reboot = MESON_WDT_DC_RESET; |
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tc_reboot |= meson_wdt->data->enable; |
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while (1) { |
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writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); |
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mdelay(5); |
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} |
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return 0; |
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} |
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static int meson_wdt_ping(struct watchdog_device *wdt_dev) |
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{ |
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struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
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writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); |
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return 0; |
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} |
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static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev, |
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unsigned int timeout) |
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{ |
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struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
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u32 reg; |
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reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); |
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reg &= ~meson_wdt->data->terminal_count_mask; |
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reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit); |
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writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
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} |
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static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev, |
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unsigned int timeout) |
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{ |
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wdt_dev->timeout = timeout; |
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meson_wdt_change_timeout(wdt_dev, timeout); |
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meson_wdt_ping(wdt_dev); |
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return 0; |
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} |
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static int meson_wdt_stop(struct watchdog_device *wdt_dev) |
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{ |
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struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
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u32 reg; |
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reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); |
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reg &= ~meson_wdt->data->enable; |
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writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
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return 0; |
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} |
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static int meson_wdt_start(struct watchdog_device *wdt_dev) |
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{ |
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struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); |
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u32 reg; |
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meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout); |
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meson_wdt_ping(wdt_dev); |
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reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); |
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reg |= meson_wdt->data->enable; |
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writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); |
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return 0; |
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} |
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static const struct watchdog_info meson_wdt_info = { |
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.identity = DRV_NAME, |
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.options = WDIOF_SETTIMEOUT | |
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WDIOF_KEEPALIVEPING | |
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WDIOF_MAGICCLOSE, |
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}; |
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static const struct watchdog_ops meson_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = meson_wdt_start, |
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.stop = meson_wdt_stop, |
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.ping = meson_wdt_ping, |
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.set_timeout = meson_wdt_set_timeout, |
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.restart = meson_wdt_restart, |
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}; |
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static const struct of_device_id meson_wdt_dt_ids[] = { |
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{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data }, |
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{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data }, |
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{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data }, |
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{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids); |
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static int meson_wdt_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct meson_wdt_dev *meson_wdt; |
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int err; |
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meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL); |
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if (!meson_wdt) |
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return -ENOMEM; |
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meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(meson_wdt->wdt_base)) |
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return PTR_ERR(meson_wdt->wdt_base); |
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meson_wdt->data = device_get_match_data(dev); |
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meson_wdt->wdt_dev.parent = dev; |
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meson_wdt->wdt_dev.info = &meson_wdt_info; |
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meson_wdt->wdt_dev.ops = &meson_wdt_ops; |
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meson_wdt->wdt_dev.max_timeout = |
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meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit; |
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meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT; |
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meson_wdt->wdt_dev.timeout = min_t(unsigned int, |
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MESON_WDT_TIMEOUT, |
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meson_wdt->wdt_dev.max_timeout); |
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watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt); |
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watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev); |
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watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout); |
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watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128); |
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meson_wdt_stop(&meson_wdt->wdt_dev); |
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watchdog_stop_on_reboot(&meson_wdt->wdt_dev); |
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err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev); |
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if (err) |
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return err; |
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dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", |
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meson_wdt->wdt_dev.timeout, nowayout); |
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return 0; |
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} |
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static struct platform_driver meson_wdt_driver = { |
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.probe = meson_wdt_probe, |
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.driver = { |
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.name = DRV_NAME, |
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.of_match_table = meson_wdt_dt_ids, |
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}, |
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}; |
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module_platform_driver(meson_wdt_driver); |
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module_param(timeout, uint, 0); |
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MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, |
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"Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Carlo Caione <[email protected]>"); |
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MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
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