166 lines
4.1 KiB
C
166 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* MOXA ART SoCs watchdog driver.
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*
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* Copyright (C) 2013 Jonas Jensen
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*
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* Jonas Jensen <jonas.jensen@gmail.com>
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*
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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/mod_devicetable.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/moduleparam.h>
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#define REG_COUNT 0x4
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#define REG_MODE 0x8
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#define REG_ENABLE 0xC
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struct moxart_wdt_dev {
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struct watchdog_device dev;
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void __iomem *base;
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unsigned int clock_frequency;
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};
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static int heartbeat;
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static int moxart_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 moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
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writel(1, moxart_wdt->base + REG_COUNT);
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writel(0x5ab9, moxart_wdt->base + REG_MODE);
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writel(0x03, moxart_wdt->base + REG_ENABLE);
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return 0;
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}
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static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
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writel(0, moxart_wdt->base + REG_ENABLE);
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return 0;
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}
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static int moxart_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
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writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
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moxart_wdt->base + REG_COUNT);
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writel(0x5ab9, moxart_wdt->base + REG_MODE);
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writel(0x03, moxart_wdt->base + REG_ENABLE);
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return 0;
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}
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static int moxart_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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return 0;
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}
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static const struct watchdog_info moxart_wdt_info = {
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.identity = "moxart-wdt",
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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};
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static const struct watchdog_ops moxart_wdt_ops = {
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.owner = THIS_MODULE,
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.start = moxart_wdt_start,
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.stop = moxart_wdt_stop,
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.set_timeout = moxart_wdt_set_timeout,
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.restart = moxart_wdt_restart,
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};
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static int moxart_wdt_probe(struct platform_device *pdev)
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{
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struct moxart_wdt_dev *moxart_wdt;
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struct device *dev = &pdev->dev;
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struct clk *clk;
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int err;
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unsigned int max_timeout;
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bool nowayout = WATCHDOG_NOWAYOUT;
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moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
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if (!moxart_wdt)
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return -ENOMEM;
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platform_set_drvdata(pdev, moxart_wdt);
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moxart_wdt->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(moxart_wdt->base))
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return PTR_ERR(moxart_wdt->base);
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clk = devm_clk_get(dev, NULL);
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if (IS_ERR(clk)) {
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pr_err("%s: of_clk_get failed\n", __func__);
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return PTR_ERR(clk);
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}
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moxart_wdt->clock_frequency = clk_get_rate(clk);
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if (moxart_wdt->clock_frequency == 0) {
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pr_err("%s: incorrect clock frequency\n", __func__);
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return -EINVAL;
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}
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max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
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moxart_wdt->dev.info = &moxart_wdt_info;
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moxart_wdt->dev.ops = &moxart_wdt_ops;
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moxart_wdt->dev.timeout = max_timeout;
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moxart_wdt->dev.min_timeout = 1;
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moxart_wdt->dev.max_timeout = max_timeout;
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moxart_wdt->dev.parent = dev;
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watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
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watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
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watchdog_set_restart_priority(&moxart_wdt->dev, 128);
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watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
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watchdog_stop_on_unregister(&moxart_wdt->dev);
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err = devm_watchdog_register_device(dev, &moxart_wdt->dev);
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if (err)
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return err;
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dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
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moxart_wdt->dev.timeout, nowayout);
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return 0;
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}
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static const struct of_device_id moxart_watchdog_match[] = {
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{ .compatible = "moxa,moxart-watchdog" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, moxart_watchdog_match);
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static struct platform_driver moxart_wdt_driver = {
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.probe = moxart_wdt_probe,
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.driver = {
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.name = "moxart-watchdog",
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.of_match_table = moxart_watchdog_match,
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},
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};
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module_platform_driver(moxart_wdt_driver);
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
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MODULE_DESCRIPTION("MOXART watchdog driver");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
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