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![Jean Delvare](/assets/img/avatar_default.png)
I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements. Either the device is enumerated and the driver already has a module alias (e.g. PCI, USB etc.) that will get the right driver loaded automatically. Or the device is not enumerated and loading its driver will lead to more or less intrusive hardware poking. Such hardware poking should be limited to a bare minimum, so the user should really decide which drivers should be tried and in what order. Trying them all in arbitrary order can't do any good. On top of that, loading that many drivers at once bloats the kernel log. Also many drivers will stay loaded afterward, bloating the output of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets loaded as a dependency) can't even be unloaded! If defining char-major-10-130 is needed then it should happen in user-space. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Mike Frysinger <vapier.adi@gmail.com> Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk> Cc: Jim Cromie <jim.cromie@gmail.com>
195 lines
4.6 KiB
C
195 lines
4.6 KiB
C
/*
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* Watchdog driver for the SA11x0/PXA2xx
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
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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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* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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*
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* 27/11/2000 Initial release
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/bitops.h>
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#include <linux/uaccess.h>
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#include <linux/timex.h>
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#ifdef CONFIG_ARCH_PXA
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#include <mach/regs-ost.h>
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#endif
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#include <mach/reset.h>
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#include <mach/hardware.h>
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static unsigned long oscr_freq;
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static unsigned long sa1100wdt_users;
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static unsigned int pre_margin;
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static int boot_status;
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/*
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* Allow only one person to hold it open
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*/
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static int sa1100dog_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(1, &sa1100wdt_users))
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return -EBUSY;
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/* Activate SA1100 Watchdog timer */
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
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writel_relaxed(OSSR_M3, OSSR);
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writel_relaxed(OWER_WME, OWER);
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writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER);
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return nonseekable_open(inode, file);
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}
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/*
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* The watchdog cannot be disabled.
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*
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* Previous comments suggested that turning off the interrupt by
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* clearing OIER[E3] would prevent the watchdog timing out but this
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* does not appear to be true (at least on the PXA255).
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*/
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static int sa1100dog_release(struct inode *inode, struct file *file)
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{
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pr_crit("Device closed - timer will not stop\n");
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clear_bit(1, &sa1100wdt_users);
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return 0;
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}
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static ssize_t sa1100dog_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len)
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/* Refresh OSMR3 timer. */
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
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| WDIOF_KEEPALIVEPING,
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.identity = "SA1100/PXA255 Watchdog",
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.firmware_version = 1,
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};
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static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user(argp, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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ret = put_user(0, p);
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break;
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(boot_status, p);
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break;
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case WDIOC_KEEPALIVE:
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, p);
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if (ret)
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break;
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if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
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ret = -EINVAL;
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break;
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}
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pre_margin = oscr_freq * time;
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
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/*fall through*/
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case WDIOC_GETTIMEOUT:
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ret = put_user(pre_margin / oscr_freq, p);
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break;
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}
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return ret;
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}
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static const struct file_operations sa1100dog_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = sa1100dog_write,
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.unlocked_ioctl = sa1100dog_ioctl,
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.open = sa1100dog_open,
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.release = sa1100dog_release,
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};
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static struct miscdevice sa1100dog_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &sa1100dog_fops,
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};
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static int margin __initdata = 60; /* (secs) Default is 1 minute */
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static int __init sa1100dog_init(void)
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{
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int ret;
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oscr_freq = get_clock_tick_rate();
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/*
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* Read the reset status, and save it for later. If
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* we suspend, RCSR will be cleared, and the watchdog
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* reset reason will be lost.
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*/
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boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
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WDIOF_CARDRESET : 0;
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pre_margin = oscr_freq * margin;
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ret = misc_register(&sa1100dog_miscdev);
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if (ret == 0)
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pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
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margin);
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return ret;
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}
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static void __exit sa1100dog_exit(void)
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{
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misc_deregister(&sa1100dog_miscdev);
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}
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module_init(sa1100dog_init);
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module_exit(sa1100dog_exit);
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MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
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MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
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module_param(margin, int, 0);
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
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MODULE_LICENSE("GPL");
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