Ignore:
Timestamp:
Apr 17, 2017, 11:38:39 AM (2 months ago)
Author:
brainslayer
Message:

change mpcore watchdog driver for laguna

File:
1 edited

Legend:

Unmodified
Added
Removed
  • src/linux/universal/linux-4.9/drivers/watchdog/mpcore_wdt.c

    r31574 r31871  
    11/*
    2  *      Watchdog driver for the mpcore watchdog timer
     2 * Watchdog driver for ARM MPcore
    33 *
    4  *      (c) Copyright 2004 ARM Limited
    5  *
    6  *      Based on the SoftDog driver:
    7  *      (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
    8  *                                              All Rights Reserved.
    9  *
    10  *      This program is free software; you can redistribute it and/or
    11  *      modify it under the terms of the GNU General Public License
    12  *      as published by the Free Software Foundation; either version
    13  *      2 of the License, or (at your option) any later version.
    14  *
    15  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
    16  *      warranty for any of this software. This material is provided
    17  *      "AS-IS" and at no charge.
    18  *
    19  *      (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
    20  *
     4 * Copyright (C) 2017 Felix Fietkau <nbd@nbd.name>
    215 */
    226
    23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
    24 
     7#include <linux/export.h>
    258#include <linux/module.h>
    26 #include <linux/moduleparam.h>
    27 #include <linux/types.h>
    28 #include <linux/miscdevice.h>
     9#include <linux/kernel.h>
    2910#include <linux/watchdog.h>
    30 #include <linux/fs.h>
    31 #include <linux/reboot.h>
    32 #include <linux/init.h>
    33 #include <linux/interrupt.h>
    3411#include <linux/platform_device.h>
    35 #include <linux/uaccess.h>
    36 #include <linux/slab.h>
    3712#include <linux/io.h>
    38 
    3913#include <asm/smp_twd.h>
    4014
    41 struct mpcore_wdt {
    42         unsigned long   timer_alive;
    43         struct device   *dev;
    44         void __iomem    *base;
    45         int             irq;
    46         unsigned int    perturb;
    47         char            expect_close;
    48 };
     15static void __iomem *wdt_base;
     16static int wdt_timeout = 60;
    4917
    50 static struct platform_device *mpcore_wdt_pdev;
    51 static DEFINE_SPINLOCK(wdt_lock);
     18static int mpcore_wdt_keepalive(struct watchdog_device *wdd)
     19{
     20        static int perturb;
     21        u32 count;
    5222
    53 #define TIMER_MARGIN    60
    54 static int mpcore_margin = TIMER_MARGIN;
    55 module_param(mpcore_margin, int, 0);
    56 MODULE_PARM_DESC(mpcore_margin,
    57         "MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
    58                                 __MODULE_STRING(TIMER_MARGIN) ")");
     23        count = (twd_timer_get_rate() / 256) * wdt_timeout;
    5924
    60 static bool nowayout = WATCHDOG_NOWAYOUT;
    61 module_param(nowayout, bool, 0);
    62 MODULE_PARM_DESC(nowayout,
    63         "Watchdog cannot be stopped once started (default="
    64                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
     25        /* Reload register needs a different value on each refresh */
     26        count += perturb;
     27        perturb = !perturb;
    6528
    66 #define ONLY_TESTING    0
    67 static int mpcore_noboot = ONLY_TESTING;
    68 module_param(mpcore_noboot, int, 0);
    69 MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
    70         "set to 1 to ignore reboots, 0 to reboot (default="
    71                                         __MODULE_STRING(ONLY_TESTING) ")");
     29        iowrite32(count, wdt_base + TWD_WDOG_LOAD);
    7230
    73 /*
    74  *      This is the interrupt handler.  Note that we only use this
    75  *      in testing mode, so don't actually do a reboot here.
    76  */
    77 static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
    78 {
    79         struct mpcore_wdt *wdt = arg;
    80 
    81         /* Check it really was our interrupt */
    82         if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
    83                 dev_crit(wdt->dev, "Triggered - Reboot ignored\n");
    84                 /* Clear the interrupt on the watchdog */
    85                 writel(1, wdt->base + TWD_WDOG_INTSTAT);
    86                 return IRQ_HANDLED;
    87         }
    88         return IRQ_NONE;
    89 }
    90 
    91 /*
    92  *      mpcore_wdt_keepalive - reload the timer
    93  *
    94  *      Note that the spec says a DIFFERENT value must be written to the reload
    95  *      register each time.  The "perturb" variable deals with this by adding 1
    96  *      to the count every other time the function is called.
    97  */
    98 static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
    99 {
    100         unsigned long count;
    101 
    102         spin_lock(&wdt_lock);
    103         /* Assume prescale is set to 256 */
    104         count =  __raw_readl(wdt->base + TWD_WDOG_COUNTER);
    105         count = (0xFFFFFFFFU - count) * (HZ / 5);
    106         count = (count / 256) * mpcore_margin;
    107 
    108         /* Reload the counter */
    109         writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
    110         wdt->perturb = wdt->perturb ? 0 : 1;
    111         spin_unlock(&wdt_lock);
    112 }
    113 
    114 static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
    115 {
    116         spin_lock(&wdt_lock);
    117         writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
    118         writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
    119         writel(0x0, wdt->base + TWD_WDOG_CONTROL);
    120         spin_unlock(&wdt_lock);
    121 }
    122 
    123 static void mpcore_wdt_start(struct mpcore_wdt *wdt)
    124 {
    125         dev_info(wdt->dev, "enabling watchdog\n");
    126 
    127         /* This loads the count register but does NOT start the count yet */
    128         mpcore_wdt_keepalive(wdt);
    129 
    130         if (mpcore_noboot) {
    131                 /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
    132                 writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
    133         } else {
    134                 /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
    135                 writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
    136         }
    137 }
    138 
    139 static int mpcore_wdt_set_heartbeat(int t)
    140 {
    141         if (t < 0x0001 || t > 0xFFFF)
    142                 return -EINVAL;
    143 
    144         mpcore_margin = t;
    14531        return 0;
    14632}
    14733
    148 /*
    149  *      /dev/watchdog handling
    150  */
    151 static int mpcore_wdt_open(struct inode *inode, struct file *file)
     34static int mpcore_wdt_start(struct watchdog_device *wdd)
    15235{
    153         struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev);
     36        mpcore_wdt_keepalive(wdd);
    15437
    155         if (test_and_set_bit(0, &wdt->timer_alive))
    156                 return -EBUSY;
     38        /* prescale = 256, mode = 1, enable = 1 */
     39        iowrite32(0x0000FF09, wdt_base + TWD_WDOG_CONTROL);
    15740
    158         if (nowayout)
    159                 __module_get(THIS_MODULE);
    160 
    161         file->private_data = wdt;
    162 
    163         /*
    164          *      Activate timer
    165          */
    166         mpcore_wdt_start(wdt);
    167 
    168         return nonseekable_open(inode, file);
    169 }
    170 
    171 static int mpcore_wdt_release(struct inode *inode, struct file *file)
    172 {
    173         struct mpcore_wdt *wdt = file->private_data;
    174 
    175         /*
    176          *      Shut off the timer.
    177          *      Lock it in if it's a module and we set nowayout
    178          */
    179         if (wdt->expect_close == 42)
    180                 mpcore_wdt_stop(wdt);
    181         else {
    182                 dev_crit(wdt->dev,
    183                          "unexpected close, not stopping watchdog!\n");
    184                 mpcore_wdt_keepalive(wdt);
    185         }
    186         clear_bit(0, &wdt->timer_alive);
    187         wdt->expect_close = 0;
    18841        return 0;
    18942}
    19043
    191 static ssize_t mpcore_wdt_write(struct file *file, const char *data,
    192                                                 size_t len, loff_t *ppos)
     44static int mpcore_wdt_stop(struct watchdog_device *wdd)
    19345{
    194         struct mpcore_wdt *wdt = file->private_data;
     46        iowrite32(0x12345678, wdt_base + TWD_WDOG_DISABLE);
     47        iowrite32(0x87654321, wdt_base + TWD_WDOG_DISABLE);
     48        iowrite32(0x0, wdt_base + TWD_WDOG_CONTROL);
    19549
    196         /*
    197          *      Refresh the timer.
    198          */
    199         if (len) {
    200                 if (!nowayout) {
    201                         size_t i;
    202 
    203                         /* In case it was set long ago */
    204                         wdt->expect_close = 0;
    205 
    206                         for (i = 0; i != len; i++) {
    207                                 char c;
    208 
    209                                 if (get_user(c, data + i))
    210                                         return -EFAULT;
    211                                 if (c == 'V')
    212                                         wdt->expect_close = 42;
    213                         }
    214                 }
    215                 mpcore_wdt_keepalive(wdt);
    216         }
    217         return len;
     50        return 0;
    21851}
    21952
    220 static const struct watchdog_info ident = {
    221         .options                = WDIOF_SETTIMEOUT |
    222                                   WDIOF_KEEPALIVEPING |
    223                                   WDIOF_MAGICCLOSE,
    224         .identity               = "MPcore Watchdog",
     53static int mpcore_wdt_set_timeout(struct watchdog_device *wdd,
     54                                 unsigned int timeout)
     55{
     56        mpcore_wdt_stop(wdd);
     57        wdt_timeout = timeout;
     58        mpcore_wdt_start(wdd);
     59
     60        return 0;
     61}
     62
     63static const struct watchdog_info mpcore_wdt_info = {
     64        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
     65        .identity = "MPcore Watchdog",
    22566};
    22667
    227 static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
    228                                                         unsigned long arg)
    229 {
    230         struct mpcore_wdt *wdt = file->private_data;
    231         int ret;
    232         union {
    233                 struct watchdog_info ident;
    234                 int i;
    235         } uarg;
    236 
    237         if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
    238                 return -ENOTTY;
    239 
    240         if (_IOC_DIR(cmd) & _IOC_WRITE) {
    241                 ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
    242                 if (ret)
    243                         return -EFAULT;
    244         }
    245 
    246         switch (cmd) {
    247         case WDIOC_GETSUPPORT:
    248                 uarg.ident = ident;
    249                 ret = 0;
    250                 break;
    251 
    252         case WDIOC_GETSTATUS:
    253         case WDIOC_GETBOOTSTATUS:
    254                 uarg.i = 0;
    255                 ret = 0;
    256                 break;
    257 
    258         case WDIOC_SETOPTIONS:
    259                 ret = -EINVAL;
    260                 if (uarg.i & WDIOS_DISABLECARD) {
    261                         mpcore_wdt_stop(wdt);
    262                         ret = 0;
    263                 }
    264                 if (uarg.i & WDIOS_ENABLECARD) {
    265                         mpcore_wdt_start(wdt);
    266                         ret = 0;
    267                 }
    268                 break;
    269 
    270         case WDIOC_KEEPALIVE:
    271                 mpcore_wdt_keepalive(wdt);
    272                 ret = 0;
    273                 break;
    274 
    275         case WDIOC_SETTIMEOUT:
    276                 ret = mpcore_wdt_set_heartbeat(uarg.i);
    277                 if (ret)
    278                         break;
    279 
    280                 mpcore_wdt_keepalive(wdt);
    281                 /* Fall */
    282         case WDIOC_GETTIMEOUT:
    283                 uarg.i = mpcore_margin;
    284                 ret = 0;
    285                 break;
    286 
    287         default:
    288                 return -ENOTTY;
    289         }
    290 
    291         if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
    292                 ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
    293                 if (ret)
    294                         ret = -EFAULT;
    295         }
    296         return ret;
    297 }
    298 
    299 /*
    300  *      System shutdown handler.  Turn off the watchdog if we're
    301  *      restarting or halting the system.
    302  */
    303 static void mpcore_wdt_shutdown(struct platform_device *pdev)
    304 {
    305         struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
    306 
    307         if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
    308                 mpcore_wdt_stop(wdt);
    309 }
    310 
    311 /*
    312  *      Kernel Interfaces
    313  */
    314 static const struct file_operations mpcore_wdt_fops = {
    315         .owner          = THIS_MODULE,
    316         .llseek         = no_llseek,
    317         .write          = mpcore_wdt_write,
    318         .unlocked_ioctl = mpcore_wdt_ioctl,
    319         .open           = mpcore_wdt_open,
    320         .release        = mpcore_wdt_release,
     68static const struct watchdog_ops mpcore_wdt_ops = {
     69        .owner = THIS_MODULE,
     70        .start = mpcore_wdt_start,
     71        .stop  = mpcore_wdt_stop,
     72        .ping  = mpcore_wdt_keepalive,
     73        .set_timeout = mpcore_wdt_set_timeout,
    32174};
    32275
    323 static struct miscdevice mpcore_wdt_miscdev = {
    324         .minor          = WATCHDOG_MINOR,
    325         .name           = "watchdog",
    326         .fops           = &mpcore_wdt_fops,
     76static struct watchdog_device mpcore_wdt = {
     77        .info = &mpcore_wdt_info,
     78        .ops = &mpcore_wdt_ops,
     79        .min_timeout = 1,
     80        .max_timeout = 65535,
    32781};
    32882
    32983static int mpcore_wdt_probe(struct platform_device *pdev)
    33084{
    331         struct mpcore_wdt *wdt;
    33285        struct resource *res;
    333         int ret;
     86        unsigned long rate = twd_timer_get_rate();
    33487
    335         /* We only accept one device, and it must have an id of -1 */
    336         if (pdev->id != -1)
    337                 return -ENODEV;
     88        pr_info("MPCore WD init. clockrate: %u prescaler: %u countrate: %u timeout: %us\n", rate, 256, rate / 256, wdt_timeout);
    33889
    33990        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     
    34192                return -ENODEV;
    34293
    343         wdt = devm_kzalloc(&pdev->dev, sizeof(struct mpcore_wdt), GFP_KERNEL);
    344         if (!wdt)
    345                 return -ENOMEM;
     94        wdt_base = devm_ioremap_resource(&pdev->dev, res);
     95        if (IS_ERR(wdt_base))
     96                return PTR_ERR(wdt_base);
    34697
    347         wdt->dev = &pdev->dev;
    348         wdt->irq = platform_get_irq(pdev, 0);
    349         if (wdt->irq >= 0) {
    350                 ret = devm_request_irq(wdt->dev, wdt->irq, mpcore_wdt_fire, 0,
    351                                 "mpcore_wdt", wdt);
    352                 if (ret) {
    353                         dev_err(wdt->dev,
    354                                 "cannot register IRQ%d for watchdog\n",
    355                                 wdt->irq);
    356                         return ret;
    357                 }
    358         }
    359 
    360         wdt->base = devm_ioremap(wdt->dev, res->start, resource_size(res));
    361         if (!wdt->base)
    362                 return -ENOMEM;
    363 
    364         mpcore_wdt_miscdev.parent = &pdev->dev;
    365         ret = misc_register(&mpcore_wdt_miscdev);
    366         if (ret) {
    367                 dev_err(wdt->dev,
    368                         "cannot register miscdev on minor=%d (err=%d)\n",
    369                         WATCHDOG_MINOR, ret);
    370                 return ret;
    371         }
    372 
    373         mpcore_wdt_stop(wdt);
    374         platform_set_drvdata(pdev, wdt);
    375         mpcore_wdt_pdev = pdev;
    376 
     98        watchdog_register_device(&mpcore_wdt);
    37799        return 0;
    378100}
    379101
    380 static int mpcore_wdt_remove(struct platform_device *pdev)
     102static int mpcore_wdt_remove(struct platform_device *dev)
    381103{
    382         platform_set_drvdata(pdev, NULL);
    383 
    384         misc_deregister(&mpcore_wdt_miscdev);
    385 
    386         mpcore_wdt_pdev = NULL;
    387 
     104        watchdog_unregister_device(&mpcore_wdt);
    388105        return 0;
    389106}
    390 
    391 #ifdef CONFIG_PM
    392 static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg)
    393 {
    394         struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
    395         mpcore_wdt_stop(wdt);           /* Turn the WDT off */
    396         return 0;
    397 }
    398 
    399 static int mpcore_wdt_resume(struct platform_device *pdev)
    400 {
    401         struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
    402         /* re-activate timer */
    403         if (test_bit(0, &wdt->timer_alive))
    404                 mpcore_wdt_start(wdt);
    405         return 0;
    406 }
    407 #else
    408 #define mpcore_wdt_suspend      NULL
    409 #define mpcore_wdt_resume       NULL
    410 #endif
    411 
    412 /* work with hotplug and coldplug */
    413 MODULE_ALIAS("platform:mpcore_wdt");
    414107
    415108static struct platform_driver mpcore_wdt_driver = {
    416109        .probe          = mpcore_wdt_probe,
    417110        .remove         = mpcore_wdt_remove,
    418         .suspend        = mpcore_wdt_suspend,
    419         .resume         = mpcore_wdt_resume,
    420         .shutdown       = mpcore_wdt_shutdown,
    421111        .driver         = {
    422                 .owner  = THIS_MODULE,
    423112                .name   = "mpcore_wdt",
    424113        },
    425114};
    426115
    427 static int __init mpcore_wdt_init(void)
    428 {
    429         /*
    430          * Check that the margin value is within it's range;
    431          * if not reset to the default
    432          */
    433         if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
    434                 mpcore_wdt_set_heartbeat(TIMER_MARGIN);
    435                 pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
    436                         TIMER_MARGIN);
    437         }
    438 
    439         pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
    440                 mpcore_noboot, mpcore_margin, nowayout);
    441 
    442         return platform_driver_register(&mpcore_wdt_driver);
    443 }
    444 
    445 static void __exit mpcore_wdt_exit(void)
    446 {
    447         platform_driver_unregister(&mpcore_wdt_driver);
    448 }
    449 
    450 module_init(mpcore_wdt_init);
    451 module_exit(mpcore_wdt_exit);
    452 
    453 MODULE_AUTHOR("ARM Limited");
    454 MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
     116module_platform_driver(mpcore_wdt_driver);
     117MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
    455118MODULE_LICENSE("GPL");
    456 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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