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b6559c8cb8
When the watchdog was configured for nowayout, and after the userspace watchdog daemon closed the dev node without sending the magic character, unloading this module stopped the watchdog hardware, which was clearly a problem. Besides, unloading the module is not possible when the userspace watchdog daemon is running, so it's safe to assume that we don't need to stop the watchdog hardware in the jz4740_wdt_remove() function. For this reason, the jz4740_wdt_remove() function can then be dropped alltogether. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: linux-watchdog@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: James Hogan <jhogan@kernel.org>
223 lines
6.1 KiB
C
223 lines
6.1 KiB
C
/*
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* Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
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* JZ4740 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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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/watchdog.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/device.h>
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#include <linux/clk.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <asm/mach-jz4740/timer.h>
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#define JZ_REG_WDT_TIMER_DATA 0x0
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#define JZ_REG_WDT_COUNTER_ENABLE 0x4
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#define JZ_REG_WDT_TIMER_COUNTER 0x8
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#define JZ_REG_WDT_TIMER_CONTROL 0xC
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#define JZ_WDT_CLOCK_PCLK 0x1
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#define JZ_WDT_CLOCK_RTC 0x2
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#define JZ_WDT_CLOCK_EXT 0x4
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#define JZ_WDT_CLOCK_DIV_SHIFT 3
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#define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define DEFAULT_HEARTBEAT 5
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#define MAX_HEARTBEAT 2048
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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 heartbeat = DEFAULT_HEARTBEAT;
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module_param(heartbeat, uint, 0);
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MODULE_PARM_DESC(heartbeat,
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"Watchdog heartbeat period in seconds from 1 to "
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__MODULE_STRING(MAX_HEARTBEAT) ", default "
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__MODULE_STRING(DEFAULT_HEARTBEAT));
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struct jz4740_wdt_drvdata {
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struct watchdog_device wdt;
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void __iomem *base;
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struct clk *rtc_clk;
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};
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static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
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return 0;
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}
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static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int new_timeout)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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unsigned int rtc_clk_rate;
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unsigned int timeout_value;
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unsigned short clock_div = JZ_WDT_CLOCK_DIV_1;
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rtc_clk_rate = clk_get_rate(drvdata->rtc_clk);
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timeout_value = rtc_clk_rate * new_timeout;
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while (timeout_value > 0xffff) {
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if (clock_div == JZ_WDT_CLOCK_DIV_1024) {
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/* Requested timeout too high;
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* use highest possible value. */
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timeout_value = 0xffff;
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break;
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}
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timeout_value >>= 2;
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clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT);
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}
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writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
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writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
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writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA);
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writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
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writew(clock_div | JZ_WDT_CLOCK_RTC,
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drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
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writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
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wdt_dev->timeout = new_timeout;
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return 0;
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}
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static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
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{
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jz4740_timer_enable_watchdog();
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jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
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return 0;
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}
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static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
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jz4740_timer_disable_watchdog();
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return 0;
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}
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static int jz4740_wdt_restart(struct watchdog_device *wdt_dev,
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unsigned long action, void *data)
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{
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wdt_dev->timeout = 0;
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jz4740_wdt_start(wdt_dev);
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return 0;
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}
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static const struct watchdog_info jz4740_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "jz4740 Watchdog",
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};
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static const struct watchdog_ops jz4740_wdt_ops = {
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.owner = THIS_MODULE,
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.start = jz4740_wdt_start,
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.stop = jz4740_wdt_stop,
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.ping = jz4740_wdt_ping,
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.set_timeout = jz4740_wdt_set_timeout,
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.restart = jz4740_wdt_restart,
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};
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#ifdef CONFIG_OF
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static const struct of_device_id jz4740_wdt_of_matches[] = {
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{ .compatible = "ingenic,jz4740-watchdog", },
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{ .compatible = "ingenic,jz4780-watchdog", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches);
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#endif
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static int jz4740_wdt_probe(struct platform_device *pdev)
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{
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struct jz4740_wdt_drvdata *drvdata;
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struct watchdog_device *jz4740_wdt;
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struct resource *res;
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int ret;
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drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata),
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GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
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heartbeat = DEFAULT_HEARTBEAT;
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jz4740_wdt = &drvdata->wdt;
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jz4740_wdt->info = &jz4740_wdt_info;
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jz4740_wdt->ops = &jz4740_wdt_ops;
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jz4740_wdt->timeout = heartbeat;
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jz4740_wdt->min_timeout = 1;
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jz4740_wdt->max_timeout = MAX_HEARTBEAT;
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jz4740_wdt->parent = &pdev->dev;
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watchdog_set_nowayout(jz4740_wdt, nowayout);
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watchdog_set_drvdata(jz4740_wdt, drvdata);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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drvdata->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(drvdata->base))
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return PTR_ERR(drvdata->base);
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drvdata->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
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if (IS_ERR(drvdata->rtc_clk)) {
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dev_err(&pdev->dev, "cannot find RTC clock\n");
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return PTR_ERR(drvdata->rtc_clk);
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}
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ret = devm_watchdog_register_device(&pdev->dev, &drvdata->wdt);
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if (ret < 0)
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return ret;
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platform_set_drvdata(pdev, drvdata);
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return 0;
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}
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static struct platform_driver jz4740_wdt_driver = {
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.probe = jz4740_wdt_probe,
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.driver = {
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.name = "jz4740-wdt",
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.of_match_table = of_match_ptr(jz4740_wdt_of_matches),
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},
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};
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module_platform_driver(jz4740_wdt_driver);
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MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
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MODULE_DESCRIPTION("jz4740 Watchdog Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:jz4740-wdt");
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