linux/drivers/watchdog/via_wdt.c
Julia Lawall 3813ff8b38 watchdog: via_wdt: replace del_timer by del_timer_sync
Use del_timer_sync to ensure that the timer is stopped on all CPUs before
the driver exits.

This change was suggested by Thomas Gleixner.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier i,t,ex;
@@
struct t i = { .remove = ex, };

@@
identifier r.ex;
@@
ex(...) {
  <...
- del_timer
+ del_timer_sync
    (...)
  ...>
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-06-10 21:38:25 +02:00

261 lines
7.4 KiB
C

/*
* VIA Chipset Watchdog Driver
*
* Copyright (C) 2011 Sigfox
* License terms: GNU General Public License (GPL) version 2
* Author: Marc Vertes <marc.vertes@sigfox.com>
* Based on a preliminary version from Harald Welte <HaraldWelte@viatech.com>
* Timer code by Wim Van Sebroeck <wim@iguana.be>
*
* Caveat: PnP must be enabled in BIOS to allow full access to watchdog
* control registers. If not, the watchdog must be configured in BIOS manually.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/device.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/timer.h>
#include <linux/watchdog.h>
/* Configuration registers relative to the pci device */
#define VIA_WDT_MMIO_BASE 0xe8 /* MMIO region base address */
#define VIA_WDT_CONF 0xec /* watchdog enable state */
/* Relevant bits for the VIA_WDT_CONF register */
#define VIA_WDT_CONF_ENABLE 0x01 /* 1: enable watchdog */
#define VIA_WDT_CONF_MMIO 0x02 /* 1: enable watchdog MMIO */
/*
* The MMIO region contains the watchog control register and the
* hardware timer counter.
*/
#define VIA_WDT_MMIO_LEN 8 /* MMIO region length in bytes */
#define VIA_WDT_CTL 0 /* MMIO addr+0: state/control reg. */
#define VIA_WDT_COUNT 4 /* MMIO addr+4: timer counter reg. */
/* Bits for the VIA_WDT_CTL register */
#define VIA_WDT_RUNNING 0x01 /* 0: stop, 1: running */
#define VIA_WDT_FIRED 0x02 /* 1: restarted by expired watchdog */
#define VIA_WDT_PWROFF 0x04 /* 0: reset, 1: poweroff */
#define VIA_WDT_DISABLED 0x08 /* 1: timer is disabled */
#define VIA_WDT_TRIGGER 0x80 /* 1: start a new countdown */
/* Hardware heartbeat in seconds */
#define WDT_HW_HEARTBEAT 1
/* Timer heartbeat (500ms) */
#define WDT_HEARTBEAT (HZ/2) /* should be <= ((WDT_HW_HEARTBEAT*HZ)/2) */
/* User space timeout in seconds */
#define WDT_TIMEOUT_MAX 1023 /* approx. 17 min. */
#define WDT_TIMEOUT 60
static int timeout = WDT_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, between 1 and 1023 "
"(default = " __MODULE_STRING(WDT_TIMEOUT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default = " __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static struct watchdog_device wdt_dev;
static struct resource wdt_res;
static void __iomem *wdt_mem;
static unsigned int mmio;
static void wdt_timer_tick(unsigned long data);
static DEFINE_TIMER(timer, wdt_timer_tick, 0, 0);
/* The timer that pings the watchdog */
static unsigned long next_heartbeat; /* the next_heartbeat for the timer */
static inline void wdt_reset(void)
{
unsigned int ctl = readl(wdt_mem);
writel(ctl | VIA_WDT_TRIGGER, wdt_mem);
}
/*
* Timer tick: the timer will make sure that the watchdog timer hardware
* is being reset in time. The conditions to do this are:
* 1) the watchog timer has been started and /dev/watchdog is open
* and there is still time left before userspace should send the
* next heartbeat/ping. (note: the internal heartbeat is much smaller
* then the external/userspace heartbeat).
* 2) the watchdog timer has been stopped by userspace.
*/
static void wdt_timer_tick(unsigned long data)
{
if (time_before(jiffies, next_heartbeat) ||
(!watchdog_active(&wdt_dev))) {
wdt_reset();
mod_timer(&timer, jiffies + WDT_HEARTBEAT);
} else
pr_crit("I will reboot your machine !\n");
}
static int wdt_ping(struct watchdog_device *wdd)
{
/* calculate when the next userspace timeout will be */
next_heartbeat = jiffies + wdd->timeout * HZ;
return 0;
}
static int wdt_start(struct watchdog_device *wdd)
{
unsigned int ctl = readl(wdt_mem);
writel(wdd->timeout, wdt_mem + VIA_WDT_COUNT);
writel(ctl | VIA_WDT_RUNNING | VIA_WDT_TRIGGER, wdt_mem);
wdt_ping(wdd);
mod_timer(&timer, jiffies + WDT_HEARTBEAT);
return 0;
}
static int wdt_stop(struct watchdog_device *wdd)
{
unsigned int ctl = readl(wdt_mem);
writel(ctl & ~VIA_WDT_RUNNING, wdt_mem);
return 0;
}
static int wdt_set_timeout(struct watchdog_device *wdd,
unsigned int new_timeout)
{
writel(new_timeout, wdt_mem + VIA_WDT_COUNT);
wdd->timeout = new_timeout;
return 0;
}
static const struct watchdog_info wdt_info = {
.identity = "VIA watchdog",
.options = WDIOF_CARDRESET |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
};
static const struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.ping = wdt_ping,
.set_timeout = wdt_set_timeout,
};
static struct watchdog_device wdt_dev = {
.info = &wdt_info,
.ops = &wdt_ops,
.min_timeout = 1,
.max_timeout = WDT_TIMEOUT_MAX,
};
static int wdt_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
unsigned char conf;
int ret = -ENODEV;
if (pci_enable_device(pdev)) {
dev_err(&pdev->dev, "cannot enable PCI device\n");
return -ENODEV;
}
/*
* Allocate a MMIO region which contains watchdog control register
* and counter, then configure the watchdog to use this region.
* This is possible only if PnP is properly enabled in BIOS.
* If not, the watchdog must be configured in BIOS manually.
*/
if (allocate_resource(&iomem_resource, &wdt_res, VIA_WDT_MMIO_LEN,
0xf0000000, 0xffffff00, 0xff, NULL, NULL)) {
dev_err(&pdev->dev, "MMIO allocation failed\n");
goto err_out_disable_device;
}
pci_write_config_dword(pdev, VIA_WDT_MMIO_BASE, wdt_res.start);
pci_read_config_byte(pdev, VIA_WDT_CONF, &conf);
conf |= VIA_WDT_CONF_ENABLE | VIA_WDT_CONF_MMIO;
pci_write_config_byte(pdev, VIA_WDT_CONF, conf);
pci_read_config_dword(pdev, VIA_WDT_MMIO_BASE, &mmio);
if (mmio) {
dev_info(&pdev->dev, "VIA Chipset watchdog MMIO: %x\n", mmio);
} else {
dev_err(&pdev->dev, "MMIO setting failed. Check BIOS.\n");
goto err_out_resource;
}
if (!request_mem_region(mmio, VIA_WDT_MMIO_LEN, "via_wdt")) {
dev_err(&pdev->dev, "MMIO region busy\n");
goto err_out_resource;
}
wdt_mem = ioremap(mmio, VIA_WDT_MMIO_LEN);
if (wdt_mem == NULL) {
dev_err(&pdev->dev, "cannot remap VIA wdt MMIO registers\n");
goto err_out_release;
}
if (timeout < 1 || timeout > WDT_TIMEOUT_MAX)
timeout = WDT_TIMEOUT;
wdt_dev.timeout = timeout;
watchdog_set_nowayout(&wdt_dev, nowayout);
if (readl(wdt_mem) & VIA_WDT_FIRED)
wdt_dev.bootstatus |= WDIOF_CARDRESET;
ret = watchdog_register_device(&wdt_dev);
if (ret)
goto err_out_iounmap;
/* start triggering, in case of watchdog already enabled by BIOS */
mod_timer(&timer, jiffies + WDT_HEARTBEAT);
return 0;
err_out_iounmap:
iounmap(wdt_mem);
err_out_release:
release_mem_region(mmio, VIA_WDT_MMIO_LEN);
err_out_resource:
release_resource(&wdt_res);
err_out_disable_device:
pci_disable_device(pdev);
return ret;
}
static void wdt_remove(struct pci_dev *pdev)
{
watchdog_unregister_device(&wdt_dev);
del_timer_sync(&timer);
iounmap(wdt_mem);
release_mem_region(mmio, VIA_WDT_MMIO_LEN);
release_resource(&wdt_res);
pci_disable_device(pdev);
}
static const struct pci_device_id wdt_pci_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700) },
{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800) },
{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
{ 0 }
};
static struct pci_driver wdt_driver = {
.name = "via_wdt",
.id_table = wdt_pci_table,
.probe = wdt_probe,
.remove = wdt_remove,
};
module_pci_driver(wdt_driver);
MODULE_AUTHOR("Marc Vertes");
MODULE_DESCRIPTION("Driver for watchdog timer on VIA chipset");
MODULE_LICENSE("GPL");