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Release 4.7 drivers/watchdog/qcom-wdt.c

Directory: drivers/watchdog
/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * 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/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>


#define WDT_RST		0x38

#define WDT_EN		0x40

#define WDT_STS		0x44

#define WDT_BITE_TIME	0x5C


struct qcom_wdt {
	
struct watchdog_device	wdd;
	
struct clk		*clk;
	
unsigned long		rate;
	
void __iomem		*base;
};


static inline struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd) { return container_of(wdd, struct qcom_wdt, wdd); }

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static int qcom_wdt_start(struct watchdog_device *wdd) { struct qcom_wdt *wdt = to_qcom_wdt(wdd); writel(0, wdt->base + WDT_EN); writel(1, wdt->base + WDT_RST); writel(wdd->timeout * wdt->rate, wdt->base + WDT_BITE_TIME); writel(1, wdt->base + WDT_EN); return 0; }

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static int qcom_wdt_stop(struct watchdog_device *wdd) { struct qcom_wdt *wdt = to_qcom_wdt(wdd); writel(0, wdt->base + WDT_EN); return 0; }

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static int qcom_wdt_ping(struct watchdog_device *wdd) { struct qcom_wdt *wdt = to_qcom_wdt(wdd); writel(1, wdt->base + WDT_RST); return 0; }

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static int qcom_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { wdd->timeout = timeout; return qcom_wdt_start(wdd); }

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static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { struct qcom_wdt *wdt = to_qcom_wdt(wdd); u32 timeout; /* * Trigger watchdog bite: * Setup BITE_TIME to be 128ms, and enable WDT. */ timeout = 128 * wdt->rate / 1000; writel(0, wdt->base + WDT_EN); writel(1, wdt->base + WDT_RST); writel(timeout, wdt->base + WDT_BITE_TIME); writel(1, wdt->base + WDT_EN); /* * Actually make sure the above sequence hits hardware before sleeping. */ wmb(); msleep(150); return 0; }

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Total99100.00%3100.00%

static const struct watchdog_ops qcom_wdt_ops = { .start = qcom_wdt_start, .stop = qcom_wdt_stop, .ping = qcom_wdt_ping, .set_timeout = qcom_wdt_set_timeout, .restart = qcom_wdt_restart, .owner = THIS_MODULE, }; static const struct watchdog_info qcom_wdt_info = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_CARDRESET, .identity = KBUILD_MODNAME, };
static int qcom_wdt_probe(struct platform_device *pdev) { struct qcom_wdt *wdt; struct resource *res; struct device_node *np = pdev->dev.of_node; u32 percpu_offset; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); /* We use CPU0's DGT for the watchdog */ if (of_property_read_u32(np, "cpu-offset", &percpu_offset)) percpu_offset = 0; res->start += percpu_offset; res->end += percpu_offset; wdt->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(wdt->base)) return PTR_ERR(wdt->base); wdt->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(wdt->clk)) { dev_err(&pdev->dev, "failed to get input clock\n"); return PTR_ERR(wdt->clk); } ret = clk_prepare_enable(wdt->clk); if (ret) { dev_err(&pdev->dev, "failed to setup clock\n"); return ret; } /* * We use the clock rate to calculate the max timeout, so ensure it's * not zero to avoid a divide-by-zero exception. * * WATCHDOG_CORE assumes units of seconds, if the WDT is clocked such * that it would bite before a second elapses it's usefulness is * limited. Bail if this is the case. */ wdt->rate = clk_get_rate(wdt->clk); if (wdt->rate == 0 || wdt->rate > 0x10000000U) { dev_err(&pdev->dev, "invalid clock rate\n"); ret = -EINVAL; goto err_clk_unprepare; } wdt->wdd.info = &qcom_wdt_info; wdt->wdd.ops = &qcom_wdt_ops; wdt->wdd.min_timeout = 1; wdt->wdd.max_timeout = 0x10000000U / wdt->rate; wdt->wdd.parent = &pdev->dev; if (readl(wdt->base + WDT_STS) & 1) wdt->wdd.bootstatus = WDIOF_CARDRESET; /* * If 'timeout-sec' unspecified in devicetree, assume a 30 second * default, unless the max timeout is less than 30 seconds, then use * the max instead. */ wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U); watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev); ret = watchdog_register_device(&wdt->wdd); if (ret) { dev_err(&pdev->dev, "failed to register watchdog\n"); goto err_clk_unprepare; } platform_set_drvdata(pdev, wdt); return 0; err_clk_unprepare: clk_disable_unprepare(wdt->clk); return ret; }

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static int qcom_wdt_remove(struct platform_device *pdev) { struct qcom_wdt *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&wdt->wdd); clk_disable_unprepare(wdt->clk); return 0; }

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static const struct of_device_id qcom_wdt_of_table[] = { { .compatible = "qcom,kpss-timer" }, { .compatible = "qcom,scss-timer" }, { }, }; MODULE_DEVICE_TABLE(of, qcom_wdt_of_table); static struct platform_driver qcom_watchdog_driver = { .probe = qcom_wdt_probe, .remove = qcom_wdt_remove, .driver = { .name = KBUILD_MODNAME, .of_match_table = qcom_wdt_of_table, }, }; module_platform_driver(qcom_watchdog_driver); MODULE_DESCRIPTION("QCOM KPSS Watchdog Driver"); MODULE_LICENSE("GPL v2");

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mathieu olivarimathieu olivari505.29%114.29%
guenter roeckguenter roeck353.70%228.57%
pratyush anandpratyush anand111.16%114.29%
Total946100.00%7100.00%
Directory: drivers/watchdog
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