forked from Minki/linux
7997ebad4d
Instead of relying on global static memory dynamically allocate the needed data. This has the benefit of some saved bytes if the driver is not in use and making it possible to bind more than one device (even though this has no known use case). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
273 lines
6.9 KiB
C
273 lines
6.9 KiB
C
/*
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* mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
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*
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* Authors: Dave Updegraff <dave@cray.org>
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* Kumar Gala <galak@kernel.crashing.org>
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* Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
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* ..and from sc520_wdt
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* Copyright (c) 2008 MontaVista Software, Inc.
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* Anton Vorontsov <avorontsov@ru.mvista.com>
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*
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* Note: it appears that you can only actually ENABLE or DISABLE the thing
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* once after POR. Once enabled, you cannot disable, and vice versa.
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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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/miscdevice.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <sysdev/fsl_soc.h>
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struct mpc8xxx_wdt {
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__be32 res0;
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__be32 swcrr; /* System watchdog control register */
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#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
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#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
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#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
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#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
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__be32 swcnr; /* System watchdog count register */
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u8 res1[2];
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__be16 swsrr; /* System watchdog service register */
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u8 res2[0xF0];
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};
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struct mpc8xxx_wdt_type {
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int prescaler;
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bool hw_enabled;
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};
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struct mpc8xxx_wdt_ddata {
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struct mpc8xxx_wdt __iomem *base;
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struct watchdog_device wdd;
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struct timer_list timer;
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spinlock_t lock;
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};
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static u16 timeout = 0xffff;
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module_param(timeout, ushort, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
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static bool reset = 1;
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module_param(reset, bool, 0);
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MODULE_PARM_DESC(reset,
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"Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
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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, "Watchdog cannot be stopped once started "
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"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static void mpc8xxx_wdt_keepalive(struct mpc8xxx_wdt_ddata *ddata)
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{
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/* Ping the WDT */
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spin_lock(&ddata->lock);
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out_be16(&ddata->base->swsrr, 0x556c);
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out_be16(&ddata->base->swsrr, 0xaa39);
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spin_unlock(&ddata->lock);
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}
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static void mpc8xxx_wdt_timer_ping(unsigned long arg)
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{
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struct mpc8xxx_wdt_ddata *ddata = (void *)arg;
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mpc8xxx_wdt_keepalive(ddata);
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/* We're pinging it twice faster than needed, just to be sure. */
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mod_timer(&ddata->timer, jiffies + HZ * ddata->wdd.timeout / 2);
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}
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static int mpc8xxx_wdt_start(struct watchdog_device *w)
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{
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struct mpc8xxx_wdt_ddata *ddata =
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container_of(w, struct mpc8xxx_wdt_ddata, wdd);
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u32 tmp = SWCRR_SWEN | SWCRR_SWPR;
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/* Good, fire up the show */
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if (reset)
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tmp |= SWCRR_SWRI;
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tmp |= timeout << 16;
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out_be32(&ddata->base->swcrr, tmp);
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del_timer_sync(&ddata->timer);
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return 0;
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}
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static int mpc8xxx_wdt_ping(struct watchdog_device *w)
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{
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struct mpc8xxx_wdt_ddata *ddata =
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container_of(w, struct mpc8xxx_wdt_ddata, wdd);
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mpc8xxx_wdt_keepalive(ddata);
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return 0;
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}
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static int mpc8xxx_wdt_stop(struct watchdog_device *w)
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{
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struct mpc8xxx_wdt_ddata *ddata =
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container_of(w, struct mpc8xxx_wdt_ddata, wdd);
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mod_timer(&ddata->timer, jiffies);
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return 0;
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}
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static struct watchdog_info mpc8xxx_wdt_info = {
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.options = WDIOF_KEEPALIVEPING,
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.firmware_version = 1,
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.identity = "MPC8xxx",
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};
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static struct watchdog_ops mpc8xxx_wdt_ops = {
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.owner = THIS_MODULE,
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.start = mpc8xxx_wdt_start,
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.ping = mpc8xxx_wdt_ping,
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.stop = mpc8xxx_wdt_stop,
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};
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static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
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{
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int ret;
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struct resource *res;
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const struct mpc8xxx_wdt_type *wdt_type;
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struct mpc8xxx_wdt_ddata *ddata;
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u32 freq = fsl_get_sys_freq();
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bool enabled;
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unsigned int timeout_sec;
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wdt_type = of_device_get_match_data(&ofdev->dev);
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if (!wdt_type)
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return -EINVAL;
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if (!freq || freq == -1)
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return -EINVAL;
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ddata = devm_kzalloc(&ofdev->dev, sizeof(*ddata), GFP_KERNEL);
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if (!ddata)
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return -ENOMEM;
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res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
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ddata->base = devm_ioremap_resource(&ofdev->dev, res);
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if (IS_ERR(ddata->base))
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return PTR_ERR(ddata->base);
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enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN;
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if (!enabled && wdt_type->hw_enabled) {
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pr_info("could not be enabled in software\n");
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return -ENOSYS;
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}
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spin_lock_init(&ddata->lock);
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setup_timer(&ddata->timer, mpc8xxx_wdt_timer_ping,
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(unsigned long)ddata);
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ddata->wdd.info = &mpc8xxx_wdt_info,
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ddata->wdd.ops = &mpc8xxx_wdt_ops,
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/* Calculate the timeout in seconds */
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timeout_sec = (timeout * wdt_type->prescaler) / freq;
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ddata->wdd.timeout = timeout_sec;
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watchdog_set_nowayout(&ddata->wdd, nowayout);
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ret = watchdog_register_device(&ddata->wdd);
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if (ret) {
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pr_err("cannot register watchdog device (err=%d)\n", ret);
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return ret;
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}
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pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n",
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reset ? "reset" : "interrupt", timeout, timeout_sec);
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/*
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* If the watchdog was previously enabled or we're running on
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* MPC8xxx, we should ping the wdt from the kernel until the
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* userspace handles it.
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*/
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if (enabled)
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mod_timer(&ddata->timer, jiffies);
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platform_set_drvdata(ofdev, ddata);
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return 0;
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}
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static int mpc8xxx_wdt_remove(struct platform_device *ofdev)
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{
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struct mpc8xxx_wdt_ddata *ddata = platform_get_drvdata(ofdev);
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pr_crit("Watchdog removed, expect the %s soon!\n",
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reset ? "reset" : "machine check exception");
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del_timer_sync(&ddata->timer);
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watchdog_unregister_device(&ddata->wdd);
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return 0;
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}
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static const struct of_device_id mpc8xxx_wdt_match[] = {
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{
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.compatible = "mpc83xx_wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x10000,
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},
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},
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{
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.compatible = "fsl,mpc8610-wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x10000,
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.hw_enabled = true,
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},
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},
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{
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.compatible = "fsl,mpc823-wdt",
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.data = &(struct mpc8xxx_wdt_type) {
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.prescaler = 0x800,
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.hw_enabled = true,
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},
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
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static struct platform_driver mpc8xxx_wdt_driver = {
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.probe = mpc8xxx_wdt_probe,
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.remove = mpc8xxx_wdt_remove,
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.driver = {
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.name = "mpc8xxx_wdt",
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.of_match_table = mpc8xxx_wdt_match,
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},
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};
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static int __init mpc8xxx_wdt_init(void)
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{
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return platform_driver_register(&mpc8xxx_wdt_driver);
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}
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arch_initcall(mpc8xxx_wdt_init);
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static void __exit mpc8xxx_wdt_exit(void)
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{
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platform_driver_unregister(&mpc8xxx_wdt_driver);
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}
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module_exit(mpc8xxx_wdt_exit);
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MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
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MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
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"uProcessors");
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MODULE_LICENSE("GPL");
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