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0397c5db1d
Use the infrastructure provided by the watchdog core to install the restart handler. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
224 lines
5.1 KiB
C
224 lines
5.1 KiB
C
/*
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* Copyright (C) 2015 Mans Rullgard <mans@mansr.com>
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* SMP86xx/SMP87xx Watchdog driver
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/bitops.h>
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#include <linux/clk.h>
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#include <linux/delay.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/platform_device.h>
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#include <linux/watchdog.h>
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#define DEFAULT_TIMEOUT 30
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static bool nowayout = WATCHDOG_NOWAYOUT;
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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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static unsigned int timeout;
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout");
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/*
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* Counter counts down from programmed value. Reset asserts when
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* the counter reaches 1.
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*/
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#define WD_COUNTER 0
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#define WD_CONFIG 4
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#define WD_CONFIG_XTAL_IN BIT(0)
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#define WD_CONFIG_DISABLE BIT(31)
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struct tangox_wdt_device {
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struct watchdog_device wdt;
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void __iomem *base;
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unsigned long clk_rate;
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struct clk *clk;
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};
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static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
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unsigned int new_timeout)
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{
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wdt->timeout = new_timeout;
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return 0;
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}
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static int tangox_wdt_start(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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u32 ticks;
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ticks = 1 + wdt->timeout * dev->clk_rate;
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writel(ticks, dev->base + WD_COUNTER);
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return 0;
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}
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static int tangox_wdt_stop(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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writel(0, dev->base + WD_COUNTER);
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return 0;
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}
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static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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u32 count;
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count = readl(dev->base + WD_COUNTER);
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if (!count)
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return 0;
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return (count - 1) / dev->clk_rate;
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}
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static const struct watchdog_info tangox_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "tangox watchdog",
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};
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static int tangox_wdt_restart(struct watchdog_device *wdt,
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unsigned long action, void *data)
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{
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struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
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writel(1, dev->base + WD_COUNTER);
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return 0;
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}
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static const struct watchdog_ops tangox_wdt_ops = {
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.start = tangox_wdt_start,
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.stop = tangox_wdt_stop,
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.set_timeout = tangox_wdt_set_timeout,
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.get_timeleft = tangox_wdt_get_timeleft,
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.restart = tangox_wdt_restart,
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};
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static int tangox_wdt_probe(struct platform_device *pdev)
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{
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struct tangox_wdt_device *dev;
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struct resource *res;
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u32 config;
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int err;
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dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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dev->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(dev->base))
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return PTR_ERR(dev->base);
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dev->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(dev->clk))
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return PTR_ERR(dev->clk);
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err = clk_prepare_enable(dev->clk);
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if (err)
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return err;
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dev->clk_rate = clk_get_rate(dev->clk);
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if (!dev->clk_rate) {
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err = -EINVAL;
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goto err;
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}
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dev->wdt.parent = &pdev->dev;
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dev->wdt.info = &tangox_wdt_info;
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dev->wdt.ops = &tangox_wdt_ops;
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dev->wdt.timeout = DEFAULT_TIMEOUT;
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dev->wdt.min_timeout = 1;
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dev->wdt.max_hw_heartbeat_ms = (U32_MAX - 1) / dev->clk_rate;
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watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
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watchdog_set_nowayout(&dev->wdt, nowayout);
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watchdog_set_drvdata(&dev->wdt, dev);
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/*
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* Deactivate counter if disable bit is set to avoid
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* accidental reset.
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*/
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config = readl(dev->base + WD_CONFIG);
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if (config & WD_CONFIG_DISABLE)
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writel(0, dev->base + WD_COUNTER);
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writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
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/*
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* Mark as active and restart with configured timeout if
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* already running.
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*/
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if (readl(dev->base + WD_COUNTER)) {
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set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
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tangox_wdt_start(&dev->wdt);
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}
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watchdog_set_restart_priority(&dev->wdt, 128);
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err = watchdog_register_device(&dev->wdt);
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if (err)
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goto err;
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platform_set_drvdata(pdev, dev);
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dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
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return 0;
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err:
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clk_disable_unprepare(dev->clk);
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return err;
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}
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static int tangox_wdt_remove(struct platform_device *pdev)
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{
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struct tangox_wdt_device *dev = platform_get_drvdata(pdev);
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tangox_wdt_stop(&dev->wdt);
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clk_disable_unprepare(dev->clk);
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watchdog_unregister_device(&dev->wdt);
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return 0;
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}
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static const struct of_device_id tangox_wdt_dt_ids[] = {
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{ .compatible = "sigma,smp8642-wdt" },
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{ .compatible = "sigma,smp8759-wdt" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
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static struct platform_driver tangox_wdt_driver = {
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.probe = tangox_wdt_probe,
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.remove = tangox_wdt_remove,
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.driver = {
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.name = "tangox-wdt",
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.of_match_table = tangox_wdt_dt_ids,
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},
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};
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module_platform_driver(tangox_wdt_driver);
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MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
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MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
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MODULE_LICENSE("GPL");
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