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221 lines
5.4 KiB
221 lines
5.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Watchdog driver for CSR Atlas7 |
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* |
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* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/io.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/platform_device.h> |
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#include <linux/watchdog.h> |
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#define ATLAS7_TIMER_WDT_INDEX 5 |
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#define ATLAS7_WDT_DEFAULT_TIMEOUT 20 |
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#define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX) |
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#define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX) |
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#define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX) |
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#define ATLAS7_WDT_CNT_EN (BIT(0) | BIT(1)) |
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#define ATLAS7_WDT_EN 0x64 |
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static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT; |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(timeout, uint, 0); |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)"); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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struct atlas7_wdog { |
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struct device *dev; |
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void __iomem *base; |
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unsigned long tick_rate; |
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struct clk *clk; |
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}; |
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static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd) |
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{ |
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struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); |
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u32 counter, match, delta; |
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counter = readl(wdt->base + ATLAS7_WDT_CNT); |
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match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH); |
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delta = match - counter; |
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return delta / wdt->tick_rate; |
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} |
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static int atlas7_wdt_ping(struct watchdog_device *wdd) |
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{ |
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struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); |
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u32 counter, match, delta; |
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counter = readl(wdt->base + ATLAS7_WDT_CNT); |
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delta = wdd->timeout * wdt->tick_rate; |
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match = counter + delta; |
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writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH); |
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return 0; |
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} |
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static int atlas7_wdt_enable(struct watchdog_device *wdd) |
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{ |
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struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); |
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atlas7_wdt_ping(wdd); |
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writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN, |
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wdt->base + ATLAS7_WDT_CNT_CTRL); |
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writel(1, wdt->base + ATLAS7_WDT_EN); |
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return 0; |
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} |
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static int atlas7_wdt_disable(struct watchdog_device *wdd) |
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{ |
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struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); |
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writel(0, wdt->base + ATLAS7_WDT_EN); |
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writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN, |
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wdt->base + ATLAS7_WDT_CNT_CTRL); |
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return 0; |
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} |
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static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) |
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{ |
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wdd->timeout = to; |
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return 0; |
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} |
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#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) |
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static const struct watchdog_info atlas7_wdt_ident = { |
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.options = OPTIONS, |
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.firmware_version = 0, |
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.identity = "atlas7 Watchdog", |
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}; |
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static const struct watchdog_ops atlas7_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = atlas7_wdt_enable, |
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.stop = atlas7_wdt_disable, |
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.get_timeleft = atlas7_wdt_gettimeleft, |
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.ping = atlas7_wdt_ping, |
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.set_timeout = atlas7_wdt_settimeout, |
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}; |
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static struct watchdog_device atlas7_wdd = { |
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.info = &atlas7_wdt_ident, |
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.ops = &atlas7_wdt_ops, |
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.timeout = ATLAS7_WDT_DEFAULT_TIMEOUT, |
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}; |
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static const struct of_device_id atlas7_wdt_ids[] = { |
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{ .compatible = "sirf,atlas7-tick"}, |
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{} |
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}; |
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static void atlas7_clk_disable_unprepare(void *data) |
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{ |
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clk_disable_unprepare(data); |
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} |
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static int atlas7_wdt_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct atlas7_wdog *wdt; |
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struct clk *clk; |
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int ret; |
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wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); |
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if (!wdt) |
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return -ENOMEM; |
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wdt->base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(wdt->base)) |
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return PTR_ERR(wdt->base); |
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clk = devm_clk_get(dev, NULL); |
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if (IS_ERR(clk)) |
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return PTR_ERR(clk); |
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ret = clk_prepare_enable(clk); |
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if (ret) { |
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dev_err(dev, "clk enable failed\n"); |
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return ret; |
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} |
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ret = devm_add_action_or_reset(dev, atlas7_clk_disable_unprepare, clk); |
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if (ret) |
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return ret; |
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/* disable watchdog hardware */ |
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writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL); |
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wdt->tick_rate = clk_get_rate(clk); |
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if (!wdt->tick_rate) |
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return -EINVAL; |
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wdt->clk = clk; |
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atlas7_wdd.min_timeout = 1; |
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atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate; |
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watchdog_init_timeout(&atlas7_wdd, 0, dev); |
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watchdog_set_nowayout(&atlas7_wdd, nowayout); |
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watchdog_set_drvdata(&atlas7_wdd, wdt); |
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platform_set_drvdata(pdev, &atlas7_wdd); |
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watchdog_stop_on_reboot(&atlas7_wdd); |
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watchdog_stop_on_unregister(&atlas7_wdd); |
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return devm_watchdog_register_device(dev, &atlas7_wdd); |
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} |
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static int __maybe_unused atlas7_wdt_suspend(struct device *dev) |
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{ |
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/* |
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* NOTE:timer controller registers settings are saved |
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* and restored back by the timer-atlas7.c |
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*/ |
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return 0; |
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} |
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static int __maybe_unused atlas7_wdt_resume(struct device *dev) |
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{ |
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struct watchdog_device *wdd = dev_get_drvdata(dev); |
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/* |
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* NOTE: Since timer controller registers settings are saved |
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* and restored back by the timer-atlas7.c, so we need not |
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* update WD settings except refreshing timeout. |
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*/ |
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atlas7_wdt_ping(wdd); |
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return 0; |
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} |
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static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops, |
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atlas7_wdt_suspend, atlas7_wdt_resume); |
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MODULE_DEVICE_TABLE(of, atlas7_wdt_ids); |
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static struct platform_driver atlas7_wdt_driver = { |
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.driver = { |
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.name = "atlas7-wdt", |
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.pm = &atlas7_wdt_pm_ops, |
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.of_match_table = atlas7_wdt_ids, |
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}, |
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.probe = atlas7_wdt_probe, |
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}; |
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module_platform_driver(atlas7_wdt_driver); |
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MODULE_DESCRIPTION("CSRatlas7 watchdog driver"); |
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MODULE_AUTHOR("Guo Zeng <[email protected]>"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:atlas7-wdt");
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