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![Maxime Ripard](/assets/img/avatar_default.png)
Most of the watchdog code is duplicated between the machine restart code and the watchdog driver. Add the restart hook to the watchdog driver, to be able to remove it from the machine code eventually. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
266 lines
6.7 KiB
C
266 lines
6.7 KiB
C
/*
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* sunxi Watchdog Driver
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*
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* Copyright (c) 2013 Carlo Caione
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* 2012 Henrik Nordstrom
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Based on xen_wdt.c
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* (c) Copyright 2010 Novell, Inc.
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/init.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/of.h>
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#include <linux/platform_device.h>
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#include <linux/reboot.h>
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#include <linux/types.h>
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#include <linux/watchdog.h>
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#include <asm/system_misc.h>
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#define WDT_MAX_TIMEOUT 16
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#define WDT_MIN_TIMEOUT 1
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#define WDT_MODE_TIMEOUT(n) ((n) << 3)
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#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
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#define WDT_CTRL 0x00
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#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
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#define WDT_MODE 0x04
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#define WDT_MODE_EN (1 << 0)
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#define WDT_MODE_RST_EN (1 << 1)
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#define DRV_NAME "sunxi-wdt"
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#define DRV_VERSION "1.0"
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static bool nowayout = WATCHDOG_NOWAYOUT;
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static unsigned int timeout = WDT_MAX_TIMEOUT;
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struct sunxi_wdt_dev {
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struct watchdog_device wdt_dev;
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void __iomem *wdt_base;
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};
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/*
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* wdt_timeout_map maps the watchdog timer interval value in seconds to
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* the value of the register WDT_MODE bit 3:6
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*
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* [timeout seconds] = register value
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*
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*/
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static const int wdt_timeout_map[] = {
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[1] = 0x1, /* 1s */
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[2] = 0x2, /* 2s */
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[3] = 0x3, /* 3s */
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[4] = 0x4, /* 4s */
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[5] = 0x5, /* 5s */
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[6] = 0x6, /* 6s */
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[8] = 0x7, /* 8s */
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[10] = 0x8, /* 10s */
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[12] = 0x9, /* 12s */
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[14] = 0xA, /* 14s */
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[16] = 0xB, /* 16s */
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};
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static void __iomem *reboot_wdt_base;
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static void sun4i_wdt_restart(enum reboot_mode mode, const char *cmd)
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{
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/* Enable timer and set reset bit in the watchdog */
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writel(WDT_MODE_EN | WDT_MODE_RST_EN, reboot_wdt_base + WDT_MODE);
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/*
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* Restart the watchdog. The default (and lowest) interval
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* value for the watchdog is 0.5s.
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*/
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writel(WDT_CTRL_RELOAD, reboot_wdt_base + WDT_CTRL);
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while (1) {
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mdelay(5);
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writel(WDT_MODE_EN | WDT_MODE_RST_EN,
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reboot_wdt_base + WDT_MODE);
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}
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}
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static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
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void __iomem *wdt_base = sunxi_wdt->wdt_base;
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iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
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return 0;
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}
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static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
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void __iomem *wdt_base = sunxi_wdt->wdt_base;
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u32 reg;
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if (wdt_timeout_map[timeout] == 0)
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timeout++;
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sunxi_wdt->wdt_dev.timeout = timeout;
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reg = ioread32(wdt_base + WDT_MODE);
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reg &= ~WDT_TIMEOUT_MASK;
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reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]);
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iowrite32(reg, wdt_base + WDT_MODE);
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sunxi_wdt_ping(wdt_dev);
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return 0;
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}
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static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
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void __iomem *wdt_base = sunxi_wdt->wdt_base;
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iowrite32(0, wdt_base + WDT_MODE);
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return 0;
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}
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static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
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{
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u32 reg;
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struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
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void __iomem *wdt_base = sunxi_wdt->wdt_base;
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int ret;
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ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
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sunxi_wdt->wdt_dev.timeout);
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if (ret < 0)
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return ret;
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reg = ioread32(wdt_base + WDT_MODE);
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reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);
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iowrite32(reg, wdt_base + WDT_MODE);
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return 0;
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}
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static const struct watchdog_info sunxi_wdt_info = {
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.identity = DRV_NAME,
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.options = WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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};
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static const struct watchdog_ops sunxi_wdt_ops = {
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.owner = THIS_MODULE,
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.start = sunxi_wdt_start,
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.stop = sunxi_wdt_stop,
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.ping = sunxi_wdt_ping,
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.set_timeout = sunxi_wdt_set_timeout,
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};
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static int sunxi_wdt_probe(struct platform_device *pdev)
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{
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struct sunxi_wdt_dev *sunxi_wdt;
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struct resource *res;
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int err;
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sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
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if (!sunxi_wdt)
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return -EINVAL;
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platform_set_drvdata(pdev, sunxi_wdt);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(sunxi_wdt->wdt_base))
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return PTR_ERR(sunxi_wdt->wdt_base);
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sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
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sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
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sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
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sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
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sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
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sunxi_wdt->wdt_dev.parent = &pdev->dev;
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watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
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watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
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watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
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sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
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err = watchdog_register_device(&sunxi_wdt->wdt_dev);
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if (unlikely(err))
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return err;
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reboot_wdt_base = sunxi_wdt->wdt_base;
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arm_pm_restart = sun4i_wdt_restart;
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dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
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sunxi_wdt->wdt_dev.timeout, nowayout);
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return 0;
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}
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static int sunxi_wdt_remove(struct platform_device *pdev)
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{
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struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
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arm_pm_restart = NULL;
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watchdog_unregister_device(&sunxi_wdt->wdt_dev);
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watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);
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return 0;
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}
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static void sunxi_wdt_shutdown(struct platform_device *pdev)
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{
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struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
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sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
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}
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static const struct of_device_id sunxi_wdt_dt_ids[] = {
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{ .compatible = "allwinner,sun4i-a10-wdt" },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
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static struct platform_driver sunxi_wdt_driver = {
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.probe = sunxi_wdt_probe,
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.remove = sunxi_wdt_remove,
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.shutdown = sunxi_wdt_shutdown,
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.driver = {
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.owner = THIS_MODULE,
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.name = DRV_NAME,
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.of_match_table = sunxi_wdt_dt_ids,
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},
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};
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module_platform_driver(sunxi_wdt_driver);
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module_param(timeout, uint, 0);
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MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
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"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
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MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
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MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
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MODULE_VERSION(DRV_VERSION);
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