[PATCH 5/10] watchdog: bcm63xx_wdt: Use WATCHDOG_CORE

Simon Arlott
2015-11-22T14:06:40Z

Convert bcm63xx_wdt to use WATCHDOG_CORE.

The default and maximum time constants that are only used once have been
moved to the initialisation of the struct watchdog_device.

Signed-off-by: Simon Arlott <simon-A6De1vDTPLDsq35pWSNszA@public.gmane.org>
---
drivers/watchdog/Kconfig | 1 +
drivers/watchdog/bcm63xx_wdt.c | 249 ++++++++++++-----------------------------
2 files changed, 74 insertions(+), 176 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 7a8a6c6..6815b74 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1273,6 +1273,7 @@ config OCTEON_WDT
config BCM63XX_WDT
tristate "Broadcom BCM63xx hardware watchdog"
depends on BCM63XX
+ select WATCHDOG_CORE
help
Watchdog driver for the built in watchdog hardware in Broadcom
BCM63xx SoC.
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
index f88fc97..1d2a501 100644
--- a/drivers/watchdog/bcm63xx_wdt.c
+++ b/drivers/watchdog/bcm63xx_wdt.c
@@ -13,20 +13,15 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-#include <linux/bitops.h>
#include <linux/errno.h>
-#include <linux/fs.h>
#include <linux/io.h>
#include <linux/kernel.h>
-#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/types.h>
-#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/interrupt.h>
-#include <linux/ptrace.h>
#include <linux/resource.h>
#include <linux/platform_device.h>

@@ -38,53 +33,57 @@
#define PFX KBUILD_MODNAME

#define WDT_HZ 50000000 /* Fclk */
-#define WDT_DEFAULT_TIME 30 /* seconds */
-#define WDT_MAX_TIME (0xffffffff / WDT_HZ) /* seconds */

struct bcm63xx_wdt_hw {
raw_spinlock_t lock;
void __iomem *regs;
- unsigned long inuse;
bool running;
};
-static struct bcm63xx_wdt_hw bcm63xx_wdt_device;

-static int expect_close;
-
-static int wdt_time = WDT_DEFAULT_TIME;
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) ")");

-/* HW functions */
-static void bcm63xx_wdt_hw_start(void)
+static int bcm63xx_wdt_start(struct watchdog_device *wdd)
{
+ struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd);
unsigned long flags;

- raw_spin_lock_irqsave(&bcm63xx_wdt_device.lock, flags);
- bcm_writel(wdt_time * WDT_HZ, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
- bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
- bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
- bcm63xx_wdt_device.running = true;
- raw_spin_unlock_irqrestore(&bcm63xx_wdt_device.lock, flags);
+ raw_spin_lock_irqsave(&hw->lock, flags);
+ bcm_writel(wdd->timeout * WDT_HZ, hw->regs + WDT_DEFVAL_REG);
+ bcm_writel(WDT_START_1, hw->regs + WDT_CTL_REG);
+ bcm_writel(WDT_START_2, hw->regs + WDT_CTL_REG);
+ hw->running = true;
+ raw_spin_unlock_irqrestore(&hw->lock, flags);
+ return 0;
}

-static void bcm63xx_wdt_hw_stop(void)
+static int bcm63xx_wdt_stop(struct watchdog_device *wdd)
{
+ struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd);
unsigned long flags;

- raw_spin_lock_irqsave(&bcm63xx_wdt_device.lock, flags);
- bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
- bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
- bcm63xx_wdt_device.running = false;
- raw_spin_unlock_irqrestore(&bcm63xx_wdt_device.lock, flags);
+ raw_spin_lock_irqsave(&hw->lock, flags);
+ bcm_writel(WDT_STOP_1, hw->regs + WDT_CTL_REG);
+ bcm_writel(WDT_STOP_2, hw->regs + WDT_CTL_REG);
+ hw->running = false;
+ raw_spin_unlock_irqrestore(&hw->lock, flags);
+ return 0;
+}
+
+static int bcm63xx_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ wdd->timeout = timeout;
+ return bcm63xx_wdt_start(wdd);
}

/* The watchdog interrupt occurs when half the timeout is remaining */
static void bcm63xx_wdt_isr(void *data)
{
- struct bcm63xx_wdt_hw *hw = &bcm63xx_wdt_device;
+ struct watchdog_device *wdd = data;
+ struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd);
unsigned long flags;

raw_spin_lock_irqsave(&hw->lock, flags);
@@ -118,147 +117,36 @@ static void bcm63xx_wdt_isr(void *data)
}

ms = timeleft / (WDT_HZ / 1000);
- pr_alert("warning timer fired, reboot in %ums\n", ms);
+ dev_alert(wdd->dev,
+ "warning timer fired, reboot in %ums\n", ms);
}
raw_spin_unlock_irqrestore(&hw->lock, flags);
}

-static int bcm63xx_wdt_settimeout(int new_time)
-{
- if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
- return -EINVAL;
-
- wdt_time = new_time;
-
- return 0;
-}
-
-static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
- return -EBUSY;
-
- bcm63xx_wdt_hw_start();
- return nonseekable_open(inode, file);
-}
-
-static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
-{
- if (expect_close == 42)
- bcm63xx_wdt_hw_stop();
- else {
- pr_crit("Unexpected close, not stopping watchdog!\n");
- bcm63xx_wdt_hw_start();
- }
- clear_bit(0, &bcm63xx_wdt_device.inuse);
- expect_close = 0;
- return 0;
-}
-
-static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
-{
- if (len) {
- if (!nowayout) {
- size_t i;
-
- /* In case it was set long ago */
- expect_close = 0;
-
- for (i = 0; i != len; i++) {
- char c;
- if (get_user(c, data + i))
- return -EFAULT;
- if (c == 'V')
- expect_close = 42;
- }
- }
- bcm63xx_wdt_hw_start();
- }
- return len;
-}
-
-static struct watchdog_info bcm63xx_wdt_info = {
- .identity = PFX,
- .options = WDIOF_SETTIMEOUT |
- WDIOF_KEEPALIVEPING |
- WDIOF_MAGICCLOSE,
-};
-
-
-static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
- int new_value, retval = -EINVAL;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- return copy_to_user(argp, &bcm63xx_wdt_info,
- sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, p);
-
- case WDIOC_SETOPTIONS:
- if (get_user(new_value, p))
- return -EFAULT;
-
- if (new_value & WDIOS_DISABLECARD) {
- bcm63xx_wdt_hw_stop();
- retval = 0;
- }
- if (new_value & WDIOS_ENABLECARD) {
- bcm63xx_wdt_hw_start();
- retval = 0;
- }
-
- return retval;
-
- case WDIOC_KEEPALIVE:
- bcm63xx_wdt_hw_start();
- return 0;
-
- case WDIOC_SETTIMEOUT:
- if (get_user(new_value, p))
- return -EFAULT;
-
- if (bcm63xx_wdt_settimeout(new_value))
- return -EINVAL;
-
- bcm63xx_wdt_hw_start();
-
- case WDIOC_GETTIMEOUT:
- return put_user(wdt_time, p);
-
- default:
- return -ENOTTY;
-
- }
-}
-
-static const struct file_operations bcm63xx_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = bcm63xx_wdt_write,
- .unlocked_ioctl = bcm63xx_wdt_ioctl,
- .open = bcm63xx_wdt_open,
- .release = bcm63xx_wdt_release,
+static struct watchdog_ops bcm63xx_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = bcm63xx_wdt_start,
+ .stop = bcm63xx_wdt_stop,
+ .set_timeout = bcm63xx_wdt_set_timeout,
};

-static struct miscdevice bcm63xx_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &bcm63xx_wdt_fops,
+static const struct watchdog_info bcm63xx_wdt_info = {
+ .options = WDIOC_GETTIMELEFT | WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "BCM63xx Watchdog",
};

-
static int bcm63xx_wdt_probe(struct platform_device *pdev)
{
- int ret;
+ struct bcm63xx_wdt_hw *hw;
+ struct watchdog_device *wdd;
struct resource *r;
+ int ret;
+
+ hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
+ wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
+ if (!hw || !wdd)
+ return -ENOMEM;

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
@@ -266,36 +154,44 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
return -ENODEV;
}

- bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
- resource_size(r));
- if (!bcm63xx_wdt_device.regs) {
+ hw->regs = devm_ioremap_nocache(&pdev->dev, r->start, resource_size(r));
+ if (!hw->regs) {
dev_err(&pdev->dev, "failed to remap I/O resources\n");
return -ENXIO;
}

- raw_spin_lock_init(&bcm63xx_wdt_device.lock);
+ raw_spin_lock_init(&hw->lock);
+ hw->running = false;
+
+ wdd->parent = &pdev->dev;
+ wdd->ops = &bcm63xx_wdt_ops;
+ wdd->info = &bcm63xx_wdt_info;
+ wdd->min_timeout = 1;
+ wdd->max_timeout = 0xffffffff / WDT_HZ;
+ wdd->timeout = min(30U, wdd->max_timeout);
+
+ watchdog_set_drvdata(wdd, hw);
+ platform_set_drvdata(pdev, wdd);
+
+ watchdog_init_timeout(wdd, 0, &pdev->dev);
+ watchdog_set_nowayout(wdd, nowayout);

- ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
+ ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, wdd);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register wdt timer isr\n");
return ret;
}

- if (bcm63xx_wdt_settimeout(wdt_time)) {
- bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
- dev_info(&pdev->dev,
- ": wdt_time value must be 1 <= wdt_time <= %d, using %d\n",
- WDT_MAX_TIME, wdt_time);
- }
-
- ret = misc_register(&bcm63xx_wdt_miscdev);
+ ret = watchdog_register_device(wdd);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register watchdog device\n");
goto unregister_timer;
}

- dev_info(&pdev->dev, " started, timer margin: %d sec\n",
- WDT_DEFAULT_TIME);
+ dev_info(&pdev->dev,
+ "%s at MMIO 0x%p (timeout = %us, max_timeout = %us)",
+ dev_name(wdd->dev), hw->regs,
+ wdd->timeout, wdd->max_timeout);

return 0;

@@ -306,17 +202,18 @@ unregister_timer:

static int bcm63xx_wdt_remove(struct platform_device *pdev)
{
- if (!nowayout)
- bcm63xx_wdt_hw_stop();
+ struct watchdog_device *wdd = platform_get_drvdata(pdev);

- misc_deregister(&bcm63xx_wdt_miscdev);
bcm63xx_timer_unregister(TIMER_WDT_ID);
+ watchdog_unregister_device(wdd);
return 0;
}

static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
{
- bcm63xx_wdt_hw_stop();
+ struct watchdog_device *wdd = platform_get_drvdata(pdev);
+
+ bcm63xx_wdt_stop(wdd);
}

static struct platform_driver bcm63xx_wdt_driver = {
--
2.1.4