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Diffstat (limited to 'drivers/char/watchdog/shwdt.c')
-rw-r--r--drivers/char/watchdog/shwdt.c110
1 files changed, 75 insertions, 35 deletions
diff --git a/drivers/char/watchdog/shwdt.c b/drivers/char/watchdog/shwdt.c
index 1355038f104..e5b8c64f1d6 100644
--- a/drivers/char/watchdog/shwdt.c
+++ b/drivers/char/watchdog/shwdt.c
@@ -27,7 +27,7 @@
#include <linux/notifier.h>
#include <linux/ioport.h>
#include <linux/fs.h>
-
+#include <linux/mm.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/watchdog.h>
@@ -125,7 +125,6 @@ static void sh_wdt_start(void)
/**
* sh_wdt_stop - Stop the Watchdog
- *
* Stops the watchdog.
*/
static void sh_wdt_stop(void)
@@ -141,22 +140,20 @@ static void sh_wdt_stop(void)
/**
* sh_wdt_keepalive - Keep the Userspace Watchdog Alive
- *
* The Userspace watchdog got a KeepAlive: schedule the next heartbeat.
*/
-static void sh_wdt_keepalive(void)
+static inline void sh_wdt_keepalive(void)
{
next_heartbeat = jiffies + (heartbeat * HZ);
}
/**
* sh_wdt_set_heartbeat - Set the Userspace Watchdog heartbeat
- *
* Set the Userspace Watchdog heartbeat
*/
static int sh_wdt_set_heartbeat(int t)
{
- if ((t < 1) || (t > 3600)) /* arbitrary upper limit */
+ if (unlikely((t < 1) || (t > 3600))) /* arbitrary upper limit */
return -EINVAL;
heartbeat = t;
@@ -165,7 +162,6 @@ static int sh_wdt_set_heartbeat(int t)
/**
* sh_wdt_ping - Ping the Watchdog
- *
* @data: Unused
*
* Clears overflow bit, resets timer counter.
@@ -182,14 +178,13 @@ static void sh_wdt_ping(unsigned long data)
sh_wdt_write_cnt(0);
mod_timer(&timer, next_ping_period(clock_division_ratio));
- } else {
- printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
- }
+ } else
+ printk(KERN_WARNING PFX "Heartbeat lost! Will not ping "
+ "the watchdog\n");
}
/**
* sh_wdt_open - Open the Device
- *
* @inode: inode of device
* @file: file handle of device
*
@@ -209,7 +204,6 @@ static int sh_wdt_open(struct inode *inode, struct file *file)
/**
* sh_wdt_close - Close the Device
- *
* @inode: inode of device
* @file: file handle of device
*
@@ -220,7 +214,8 @@ static int sh_wdt_close(struct inode *inode, struct file *file)
if (shwdt_expect_close == 42) {
sh_wdt_stop();
} else {
- printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+ printk(KERN_CRIT PFX "Unexpected close, not "
+ "stopping watchdog!\n");
sh_wdt_keepalive();
}
@@ -232,7 +227,6 @@ static int sh_wdt_close(struct inode *inode, struct file *file)
/**
* sh_wdt_write - Write to Device
- *
* @file: file handle of device
* @buf: buffer to write
* @count: length of buffer
@@ -264,8 +258,56 @@ static ssize_t sh_wdt_write(struct file *file, const char *buf,
}
/**
- * sh_wdt_ioctl - Query Device
+ * sh_wdt_mmap - map WDT/CPG registers into userspace
+ * @file: file structure for the device
+ * @vma: VMA to map the registers into
+ *
+ * A simple mmap() implementation for the corner cases where the counter
+ * needs to be mapped in userspace directly. Due to the relatively small
+ * size of the area, neighbouring registers not necessarily tied to the
+ * CPG will also be accessible through the register page, so this remains
+ * configurable for users that really know what they're doing.
*
+ * Additionaly, the register page maps in the CPG register base relative
+ * to the nearest page-aligned boundary, which requires that userspace do
+ * the appropriate CPU subtype math for calculating the page offset for
+ * the counter value.
+ */
+static int sh_wdt_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int ret = -ENOSYS;
+
+#ifdef CONFIG_SH_WDT_MMAP
+ unsigned long addr;
+
+ /* Only support the simple cases where we map in a register page. */
+ if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
+ return -EINVAL;
+
+ /*
+ * Pick WTCNT as the start, it's usually the first register after the
+ * FRQCR, and neither one are generally page-aligned out of the box.
+ */
+ addr = WTCNT & ~(PAGE_SIZE - 1);
+
+ vma->vm_flags |= VM_IO;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+ if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
+ PAGE_SIZE, vma->vm_page_prot)) {
+ printk(KERN_ERR PFX "%s: io_remap_pfn_range failed\n",
+ __FUNCTION__);
+ return -EAGAIN;
+ }
+
+ ret = 0;
+#endif
+
+ return ret;
+}
+
+/**
+ * sh_wdt_ioctl - Query Device
* @inode: inode of device
* @file: file handle of device
* @cmd: watchdog command
@@ -326,7 +368,6 @@ static int sh_wdt_ioctl(struct inode *inode, struct file *file,
/**
* sh_wdt_notify_sys - Notifier Handler
- *
* @this: notifier block
* @code: notifier event
* @unused: unused
@@ -337,9 +378,8 @@ static int sh_wdt_ioctl(struct inode *inode, struct file *file,
static int sh_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
- if (code == SYS_DOWN || code == SYS_HALT) {
+ if (code == SYS_DOWN || code == SYS_HALT)
sh_wdt_stop();
- }
return NOTIFY_DONE;
}
@@ -351,10 +391,12 @@ static const struct file_operations sh_wdt_fops = {
.ioctl = sh_wdt_ioctl,
.open = sh_wdt_open,
.release = sh_wdt_close,
+ .mmap = sh_wdt_mmap,
};
static struct watchdog_info sh_wdt_info = {
- .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "SH WDT",
};
@@ -371,7 +413,6 @@ static struct miscdevice sh_wdt_miscdev = {
/**
* sh_wdt_init - Initialize module
- *
* Registers the device and notifier handler. Actual device
* initialization is handled by sh_wdt_open().
*/
@@ -381,15 +422,15 @@ static int __init sh_wdt_init(void)
if ((clock_division_ratio < 0x5) || (clock_division_ratio > 0x7)) {
clock_division_ratio = WTCSR_CKS_4096;
- printk(KERN_INFO PFX "clock_division_ratio value must be 0x5<=x<=0x7, using %d\n",
- clock_division_ratio);
+ printk(KERN_INFO PFX "clock_division_ratio value must "
+ "be 0x5<=x<=0x7, using %d\n", clock_division_ratio);
}
- if (sh_wdt_set_heartbeat(heartbeat))
- {
+ rc = sh_wdt_set_heartbeat(heartbeat);
+ if (unlikely(rc)) {
heartbeat = WATCHDOG_HEARTBEAT;
- printk(KERN_INFO PFX "heartbeat value must be 1<=x<=3600, using %d\n",
- heartbeat);
+ printk(KERN_INFO PFX "heartbeat value must "
+ "be 1<=x<=3600, using %d\n", heartbeat);
}
init_timer(&timer);
@@ -397,15 +438,16 @@ static int __init sh_wdt_init(void)
timer.data = 0;
rc = register_reboot_notifier(&sh_wdt_notifier);
- if (rc) {
- printk(KERN_ERR PFX "Can't register reboot notifier (err=%d)\n", rc);
+ if (unlikely(rc)) {
+ printk(KERN_ERR PFX "Can't register reboot notifier (err=%d)\n",
+ rc);
return rc;
}
rc = misc_register(&sh_wdt_miscdev);
- if (rc) {
- printk(KERN_ERR PFX "Can't register miscdev on minor=%d (err=%d)\n",
- sh_wdt_miscdev.minor, rc);
+ if (unlikely(rc)) {
+ printk(KERN_ERR PFX "Can't register miscdev on "
+ "minor=%d (err=%d)\n", sh_wdt_miscdev.minor, rc);
unregister_reboot_notifier(&sh_wdt_notifier);
return rc;
}
@@ -418,7 +460,6 @@ static int __init sh_wdt_init(void)
/**
* sh_wdt_exit - Deinitialize module
- *
* Unregisters the device and notifier handler. Actual device
* deinitialization is handled by sh_wdt_close().
*/
@@ -434,14 +475,13 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(clock_division_ratio, int, 0);
-MODULE_PARM_DESC(clock_division_ratio, "Clock division ratio. Valid ranges are from 0x5 (1.31ms) to 0x7 (5.25ms). Defaults to 0x7.");
+MODULE_PARM_DESC(clock_division_ratio, "Clock division ratio. Valid ranges are from 0x5 (1.31ms) to 0x7 (5.25ms). (default=" __MODULE_STRING(clock_division_ratio) ")");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (1<=heartbeat<=3600, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
module_init(sh_wdt_init);
module_exit(sh_wdt_exit);
-
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-30 23:24:34 +0000