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![Julia Lawall](/assets/img/avatar_default.png)
Request_mem_region should be used with release_mem_region, not release_resource. In pnx4008_wdt.c, a missing clk_put is added as well. The semantic match that finds the first problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x,E; @@ *x = request_mem_region(...) ... when != release_mem_region(x) when != x = E * release_resource(x); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Cc: stable <stable@kernel.org>
399 lines
8.8 KiB
C
399 lines
8.8 KiB
C
/*
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* drivers/char/watchdog/max63xx_wdt.c
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*
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* Driver for max63{69,70,71,72,73,74} watchdog timers
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*
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* Copyright (C) 2009 Marc Zyngier <maz@misterjones.org>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*
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* This driver assumes the watchdog pins are memory mapped (as it is
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* the case for the Arcom Zeus). Should it be connected over GPIOs or
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* another interface, some abstraction will have to be introduced.
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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/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/bitops.h>
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#include <linux/platform_device.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#define DEFAULT_HEARTBEAT 60
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#define MAX_HEARTBEAT 60
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static int heartbeat = DEFAULT_HEARTBEAT;
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static int nowayout = WATCHDOG_NOWAYOUT;
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/*
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* Memory mapping: a single byte, 3 first lower bits to select bit 3
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* to ping the watchdog.
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*/
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#define MAX6369_WDSET (7 << 0)
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#define MAX6369_WDI (1 << 3)
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static DEFINE_SPINLOCK(io_lock);
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static unsigned long wdt_status;
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#define WDT_IN_USE 0
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#define WDT_RUNNING 1
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#define WDT_OK_TO_CLOSE 2
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static int nodelay;
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static struct resource *wdt_mem;
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static void __iomem *wdt_base;
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static struct platform_device *max63xx_pdev;
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/*
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* The timeout values used are actually the absolute minimum the chip
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* offers. Typical values on my board are slightly over twice as long
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* (10s setting ends up with a 25s timeout), and can be up to 3 times
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* the nominal setting (according to the datasheet). So please take
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* these values with a grain of salt. Same goes for the initial delay
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* "feature". Only max6373/74 have a few settings without this initial
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* delay (selected with the "nodelay" parameter).
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*
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* I also decided to remove from the tables any timeout smaller than a
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* second, as it looked completly overkill...
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*/
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/* Timeouts in second */
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struct max63xx_timeout {
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u8 wdset;
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u8 tdelay;
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u8 twd;
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};
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static struct max63xx_timeout max6369_table[] = {
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{ 5, 1, 1 },
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{ 6, 10, 10 },
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{ 7, 60, 60 },
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{ },
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};
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static struct max63xx_timeout max6371_table[] = {
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{ 6, 60, 3 },
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{ 7, 60, 60 },
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{ },
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};
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static struct max63xx_timeout max6373_table[] = {
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{ 2, 60, 1 },
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{ 5, 0, 1 },
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{ 1, 3, 3 },
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{ 7, 60, 10 },
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{ 6, 0, 10 },
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{ },
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};
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static struct max63xx_timeout *current_timeout;
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static struct max63xx_timeout *
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max63xx_select_timeout(struct max63xx_timeout *table, int value)
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{
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while (table->twd) {
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if (value <= table->twd) {
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if (nodelay && table->tdelay == 0)
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return table;
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if (!nodelay)
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return table;
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}
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table++;
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}
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return NULL;
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}
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static void max63xx_wdt_ping(void)
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{
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u8 val;
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spin_lock(&io_lock);
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val = __raw_readb(wdt_base);
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__raw_writeb(val | MAX6369_WDI, wdt_base);
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__raw_writeb(val & ~MAX6369_WDI, wdt_base);
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spin_unlock(&io_lock);
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}
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static void max63xx_wdt_enable(struct max63xx_timeout *entry)
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{
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u8 val;
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if (test_and_set_bit(WDT_RUNNING, &wdt_status))
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return;
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spin_lock(&io_lock);
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val = __raw_readb(wdt_base);
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val &= ~MAX6369_WDSET;
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val |= entry->wdset;
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__raw_writeb(val, wdt_base);
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spin_unlock(&io_lock);
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/* check for a edge triggered startup */
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if (entry->tdelay == 0)
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max63xx_wdt_ping();
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}
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static void max63xx_wdt_disable(void)
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{
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u8 val;
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spin_lock(&io_lock);
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val = __raw_readb(wdt_base);
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val &= ~MAX6369_WDSET;
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val |= 3;
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__raw_writeb(val, wdt_base);
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spin_unlock(&io_lock);
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clear_bit(WDT_RUNNING, &wdt_status);
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}
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static int max63xx_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(WDT_IN_USE, &wdt_status))
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return -EBUSY;
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max63xx_wdt_enable(current_timeout);
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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return nonseekable_open(inode, file);
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}
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static ssize_t max63xx_wdt_write(struct file *file, const char *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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if (!nowayout) {
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size_t i;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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set_bit(WDT_OK_TO_CLOSE, &wdt_status);
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}
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}
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max63xx_wdt_ping();
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}
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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_MAGICCLOSE | WDIOF_KEEPALIVEPING,
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.identity = "max63xx Watchdog",
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};
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static long max63xx_wdt_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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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user((struct watchdog_info *)arg, &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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case WDIOC_GETBOOTSTATUS:
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ret = put_user(0, (int *)arg);
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break;
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case WDIOC_KEEPALIVE:
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max63xx_wdt_ping();
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ret = 0;
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break;
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case WDIOC_GETTIMEOUT:
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ret = put_user(heartbeat, (int *)arg);
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break;
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}
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return ret;
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}
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static int max63xx_wdt_release(struct inode *inode, struct file *file)
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{
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if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
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max63xx_wdt_disable();
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else
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dev_crit(&max63xx_pdev->dev,
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"device closed unexpectedly - timer will not stop\n");
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clear_bit(WDT_IN_USE, &wdt_status);
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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return 0;
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}
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static const struct file_operations max63xx_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = max63xx_wdt_write,
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.unlocked_ioctl = max63xx_wdt_ioctl,
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.open = max63xx_wdt_open,
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.release = max63xx_wdt_release,
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};
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static struct miscdevice max63xx_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &max63xx_wdt_fops,
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};
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static int __devinit max63xx_wdt_probe(struct platform_device *pdev)
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{
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int ret = 0;
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int size;
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struct device *dev = &pdev->dev;
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struct max63xx_timeout *table;
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table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
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if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
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heartbeat = DEFAULT_HEARTBEAT;
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dev_info(dev, "requesting %ds heartbeat\n", heartbeat);
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current_timeout = max63xx_select_timeout(table, heartbeat);
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if (!current_timeout) {
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dev_err(dev, "unable to satisfy heartbeat request\n");
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return -EINVAL;
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}
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dev_info(dev, "using %ds heartbeat with %ds initial delay\n",
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current_timeout->twd, current_timeout->tdelay);
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heartbeat = current_timeout->twd;
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max63xx_pdev = pdev;
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wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (wdt_mem == NULL) {
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dev_err(dev, "failed to get memory region resource\n");
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return -ENOENT;
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}
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size = resource_size(wdt_mem);
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if (!request_mem_region(wdt_mem->start, size, pdev->name)) {
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dev_err(dev, "failed to get memory region\n");
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return -ENOENT;
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}
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wdt_base = ioremap(wdt_mem->start, size);
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if (!wdt_base) {
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dev_err(dev, "failed to map memory region\n");
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ret = -ENOMEM;
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goto out_request;
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}
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ret = misc_register(&max63xx_wdt_miscdev);
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if (ret < 0) {
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dev_err(dev, "cannot register misc device\n");
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goto out_unmap;
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}
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return 0;
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out_unmap:
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iounmap(wdt_base);
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out_request:
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release_mem_region(wdt_mem->start, size);
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wdt_mem = NULL;
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return ret;
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}
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static int __devexit max63xx_wdt_remove(struct platform_device *pdev)
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{
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misc_deregister(&max63xx_wdt_miscdev);
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if (wdt_mem) {
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release_mem_region(wdt_mem->start, resource_size(wdt_mem));
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wdt_mem = NULL;
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}
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if (wdt_base)
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iounmap(wdt_base);
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return 0;
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}
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static struct platform_device_id max63xx_id_table[] = {
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{ "max6369_wdt", (kernel_ulong_t)max6369_table, },
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{ "max6370_wdt", (kernel_ulong_t)max6369_table, },
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{ "max6371_wdt", (kernel_ulong_t)max6371_table, },
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{ "max6372_wdt", (kernel_ulong_t)max6371_table, },
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{ "max6373_wdt", (kernel_ulong_t)max6373_table, },
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{ "max6374_wdt", (kernel_ulong_t)max6373_table, },
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{ },
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};
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MODULE_DEVICE_TABLE(platform, max63xx_id_table);
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static struct platform_driver max63xx_wdt_driver = {
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.probe = max63xx_wdt_probe,
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.remove = __devexit_p(max63xx_wdt_remove),
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.id_table = max63xx_id_table,
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.driver = {
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.name = "max63xx_wdt",
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.owner = THIS_MODULE,
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},
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};
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static int __init max63xx_wdt_init(void)
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{
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return platform_driver_register(&max63xx_wdt_driver);
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}
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static void __exit max63xx_wdt_exit(void)
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{
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platform_driver_unregister(&max63xx_wdt_driver);
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}
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module_init(max63xx_wdt_init);
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module_exit(max63xx_wdt_exit);
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MODULE_AUTHOR("Marc Zyngier <maz@misterjones.org>");
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MODULE_DESCRIPTION("max63xx Watchdog Driver");
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module_param(heartbeat, int, 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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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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module_param(nodelay, int, 0);
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MODULE_PARM_DESC(nodelay,
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"Force selection of a timeout setting without initial delay "
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"(max6373/74 only, default=0)");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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