mirror of https://gitee.com/openkylin/linux.git
237 lines
5.5 KiB
C
237 lines
5.5 KiB
C
/*
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* Watchdog driver for Faraday Technology FTWDT010
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*
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* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
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*
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* Inspired by the out-of-tree drivers from OpenWRT:
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* Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/bitops.h>
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#include <linux/init.h>
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#include <linux/interrupt.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/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/watchdog.h>
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#define FTWDT010_WDCOUNTER 0x0
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#define FTWDT010_WDLOAD 0x4
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#define FTWDT010_WDRESTART 0x8
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#define FTWDT010_WDCR 0xC
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#define WDRESTART_MAGIC 0x5AB9
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#define WDCR_CLOCK_5MHZ BIT(4)
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#define WDCR_WDEXT BIT(3)
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#define WDCR_WDINTR BIT(2)
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#define WDCR_SYS_RST BIT(1)
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#define WDCR_ENABLE BIT(0)
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#define WDT_CLOCK 5000000 /* 5 MHz */
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struct ftwdt010_wdt {
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struct watchdog_device wdd;
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struct device *dev;
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void __iomem *base;
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bool has_irq;
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};
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static inline
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struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd)
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{
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return container_of(wdd, struct ftwdt010_wdt, wdd);
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}
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static int ftwdt010_wdt_start(struct watchdog_device *wdd)
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{
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struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
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u32 enable;
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writel(wdd->timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD);
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writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
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/* set clock before enabling */
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enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST;
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writel(enable, gwdt->base + FTWDT010_WDCR);
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if (gwdt->has_irq)
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enable |= WDCR_WDINTR;
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enable |= WDCR_ENABLE;
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writel(enable, gwdt->base + FTWDT010_WDCR);
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return 0;
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}
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static int ftwdt010_wdt_stop(struct watchdog_device *wdd)
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{
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struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
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writel(0, gwdt->base + FTWDT010_WDCR);
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return 0;
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}
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static int ftwdt010_wdt_ping(struct watchdog_device *wdd)
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{
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struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
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writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
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return 0;
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}
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static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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wdd->timeout = timeout;
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if (watchdog_active(wdd))
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ftwdt010_wdt_start(wdd);
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return 0;
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}
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static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data)
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{
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struct ftwdt010_wdt *gwdt = data;
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watchdog_notify_pretimeout(&gwdt->wdd);
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return IRQ_HANDLED;
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}
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static const struct watchdog_ops ftwdt010_wdt_ops = {
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.start = ftwdt010_wdt_start,
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.stop = ftwdt010_wdt_stop,
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.ping = ftwdt010_wdt_ping,
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.set_timeout = ftwdt010_wdt_set_timeout,
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.owner = THIS_MODULE,
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};
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static const struct watchdog_info ftwdt010_wdt_info = {
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.options = WDIOF_KEEPALIVEPING
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| WDIOF_MAGICCLOSE
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| WDIOF_SETTIMEOUT,
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.identity = KBUILD_MODNAME,
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};
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static int ftwdt010_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct resource *res;
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struct ftwdt010_wdt *gwdt;
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unsigned int reg;
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int irq;
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int ret;
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gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
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if (!gwdt)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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gwdt->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(gwdt->base))
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return PTR_ERR(gwdt->base);
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gwdt->dev = dev;
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gwdt->wdd.info = &ftwdt010_wdt_info;
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gwdt->wdd.ops = &ftwdt010_wdt_ops;
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gwdt->wdd.min_timeout = 1;
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gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK;
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gwdt->wdd.parent = dev;
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/*
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* If 'timeout-sec' unspecified in devicetree, assume a 13 second
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* default.
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*/
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gwdt->wdd.timeout = 13U;
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watchdog_init_timeout(&gwdt->wdd, 0, dev);
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reg = readw(gwdt->base + FTWDT010_WDCR);
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if (reg & WDCR_ENABLE) {
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/* Watchdog was enabled by the bootloader, disable it. */
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reg &= ~WDCR_ENABLE;
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writel(reg, gwdt->base + FTWDT010_WDCR);
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}
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irq = platform_get_irq(pdev, 0);
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if (irq) {
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ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
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"watchdog bark", gwdt);
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if (ret)
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return ret;
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gwdt->has_irq = true;
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}
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ret = devm_watchdog_register_device(dev, &gwdt->wdd);
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if (ret) {
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dev_err(&pdev->dev, "failed to register watchdog\n");
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return ret;
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}
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/* Set up platform driver data */
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platform_set_drvdata(pdev, gwdt);
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dev_info(dev, "FTWDT010 watchdog driver enabled\n");
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return 0;
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}
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static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev)
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{
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struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
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unsigned int reg;
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reg = readw(gwdt->base + FTWDT010_WDCR);
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reg &= ~WDCR_ENABLE;
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writel(reg, gwdt->base + FTWDT010_WDCR);
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return 0;
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}
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static int __maybe_unused ftwdt010_wdt_resume(struct device *dev)
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{
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struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev);
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unsigned int reg;
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if (watchdog_active(&gwdt->wdd)) {
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reg = readw(gwdt->base + FTWDT010_WDCR);
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reg |= WDCR_ENABLE;
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writel(reg, gwdt->base + FTWDT010_WDCR);
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}
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return 0;
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}
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static const struct dev_pm_ops ftwdt010_wdt_dev_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(ftwdt010_wdt_suspend,
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ftwdt010_wdt_resume)
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};
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#ifdef CONFIG_OF
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static const struct of_device_id ftwdt010_wdt_match[] = {
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{ .compatible = "faraday,ftwdt010" },
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{ .compatible = "cortina,gemini-watchdog" },
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{},
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};
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MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match);
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#endif
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static struct platform_driver ftwdt010_wdt_driver = {
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.probe = ftwdt010_wdt_probe,
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.driver = {
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.name = "ftwdt010-wdt",
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.of_match_table = of_match_ptr(ftwdt010_wdt_match),
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.pm = &ftwdt010_wdt_dev_pm_ops,
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},
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};
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module_platform_driver(ftwdt010_wdt_driver);
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MODULE_AUTHOR("Linus Walleij");
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MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010");
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MODULE_LICENSE("GPL");
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