watchdog: Convert txx9wdt driver to watchdog framework

This patch converts txx9wdt driver to watchdog framework.
Also use devm_* APIs to save a few error handling code.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 37 insertions, 118 deletions

diff --git a/drivers/watchdog/txx9wdt.c b/drivers/watchdog/txx9wdt.c
index d02804ccd280..53f1b17429c6 100644
--- a/drivers/watchdog/txx9wdt.c
+++ b/drivers/watchdog/txx9wdt.c
@@ -15,9 +15,7 @@
 #include <linux/types.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
-#include <linux/fs.h>
 #include <linux/init.h>
-#include <linux/uaccess.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/err.h>
@@ -43,20 +41,19 @@ MODULE_PARM_DESC(nowayout,
 #define WD_TIMER_CLK    (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
 #define WD_MAX_TIMEOUT  ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
 
-static unsigned long txx9wdt_alive;
-static int expect_close;
 static struct txx9_tmr_reg __iomem *txx9wdt_reg;
 static struct clk *txx9_imclk;
 static DEFINE_SPINLOCK(txx9_lock);
 
-static void txx9wdt_ping(void)
+static int txx9wdt_ping(struct watchdog_device *wdt_dev)
 {
         spin_lock(&txx9_lock);
         __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
         spin_unlock(&txx9_lock);
+        return 0;
 }
 
-static void txx9wdt_start(void)
+static int txx9wdt_start(struct watchdog_device *wdt_dev)
 {
         spin_lock(&txx9_lock);
         __raw_writel(WD_TIMER_CLK * timeout, &txx9wdt_reg->cpra);
@@ -66,120 +63,44 @@ static void txx9wdt_start(void)
                      &txx9wdt_reg->tcr);
         __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
         spin_unlock(&txx9_lock);
+        return 0;
 }
 
-static void txx9wdt_stop(void)
+static int txx9wdt_stop(struct watchdog_device *wdt_dev)
 {
         spin_lock(&txx9_lock);
         __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
         __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
                      &txx9wdt_reg->tcr);
         spin_unlock(&txx9_lock);
-}
-
-static int txx9wdt_open(struct inode *inode, struct file *file)
-{
-        if (test_and_set_bit(0, &txx9wdt_alive))
-                return -EBUSY;
-
-        if (__raw_readl(&txx9wdt_reg->tcr) & TXx9_TMTCR_TCE) {
-                clear_bit(0, &txx9wdt_alive);
-                return -EBUSY;
-        }
-
-        if (nowayout)
-                __module_get(THIS_MODULE);
-
-        txx9wdt_start();
-        return nonseekable_open(inode, file);
-}
-
-static int txx9wdt_release(struct inode *inode, struct file *file)
-{
-        if (expect_close)
-                txx9wdt_stop();
-        else {
-                pr_crit("Unexpected close, not stopping watchdog!\n");
-                txx9wdt_ping();
-        }
-        clear_bit(0, &txx9wdt_alive);
-        expect_close = 0;
         return 0;
 }
 
-static ssize_t txx9wdt_write(struct file *file, const char __user *data,
-                             size_t len, loff_t *ppos)
+static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
+                               unsigned int new_timeout)
 {
-        if (len) {
-                if (!nowayout) {
-                        size_t i;
-
-                        expect_close = 0;
-                        for (i = 0; i != len; i++) {
-                                char c;
-                                if (get_user(c, data + i))
-                                        return -EFAULT;
-                                if (c == 'V')
-                                        expect_close = 1;
-                        }
-                }
-                txx9wdt_ping();
-        }
-        return len;
+        timeout = new_timeout;
+        txx9wdt_stop(wdt_dev);
+        txx9wdt_start(wdt_dev);
+        return 0;
 }
 
-static long txx9wdt_ioctl(struct file *file, unsigned int cmd,
-                                                        unsigned long arg)
-{
-        void __user *argp = (void __user *)arg;
-        int __user *p = argp;
-        int new_timeout;
-        static const struct watchdog_info ident = {
-                .options =              WDIOF_SETTIMEOUT |
-                                        WDIOF_KEEPALIVEPING |
-                                        WDIOF_MAGICCLOSE,
-                .firmware_version =     0,
-                .identity =             "Hardware Watchdog for TXx9",
-        };
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                return put_user(0, p);
-        case WDIOC_KEEPALIVE:
-                txx9wdt_ping();
-                return 0;
-        case WDIOC_SETTIMEOUT:
-                if (get_user(new_timeout, p))
-                        return -EFAULT;
-                if (new_timeout < 1 || new_timeout > WD_MAX_TIMEOUT)
-                        return -EINVAL;
-                timeout = new_timeout;
-                txx9wdt_stop();
-                txx9wdt_start();
-                /* Fall */
-        case WDIOC_GETTIMEOUT:
-                return put_user(timeout, p);
-        default:
-                return -ENOTTY;
-        }
-}
+static const struct watchdog_info txx9wdt_info = {
+        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+        .identity = "Hardware Watchdog for TXx9",
+};
 
-static const struct file_operations txx9wdt_fops = {
-        .owner          =       THIS_MODULE,
-        .llseek         =       no_llseek,
-        .write          =       txx9wdt_write,
-        .unlocked_ioctl =       txx9wdt_ioctl,
-        .open           =       txx9wdt_open,
-        .release        =       txx9wdt_release,
+static const struct watchdog_ops txx9wdt_ops = {
+        .owner = THIS_MODULE,
+        .start = txx9wdt_start,
+        .stop = txx9wdt_stop,
+        .ping = txx9wdt_ping,
+        .set_timeout = txx9wdt_set_timeout,
 };
 
-static struct miscdevice txx9wdt_miscdev = {
-        .minor  =       WATCHDOG_MINOR,
-        .name   =       "watchdog",
-        .fops   =       &txx9wdt_fops,
+static struct watchdog_device txx9wdt = {
+        .info = &txx9wdt_info,
+        .ops = &txx9wdt_ops,
 };
 
 static int __init txx9wdt_probe(struct platform_device *dev)
@@ -201,26 +122,24 @@ static int __init txx9wdt_probe(struct platform_device *dev)
         }
 
         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
-        if (!res)
-                goto exit_busy;
-        if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
-                                     "txx9wdt"))
-                goto exit_busy;
-        txx9wdt_reg = devm_ioremap(&dev->dev, res->start, resource_size(res));
-        if (!txx9wdt_reg)
-                goto exit_busy;
-
-        ret = misc_register(&txx9wdt_miscdev);
-        if (ret) {
+        txx9wdt_reg = devm_request_and_ioremap(&dev->dev, res);
+        if (!txx9wdt_reg) {
+                ret = -EBUSY;
                 goto exit;
         }
 
+        txx9wdt.min_timeout = 1;
+        txx9wdt.max_timeout = WD_MAX_TIMEOUT;
+        watchdog_set_nowayout(&txx9wdt, nowayout);
+
+        ret = watchdog_register_device(&txx9wdt);
+        if (ret)
+                goto exit;
+
         pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
                 timeout, WD_MAX_TIMEOUT, nowayout);
 
         return 0;
-exit_busy:
-        ret = -EBUSY;
 exit:
         if (txx9_imclk) {
                 clk_disable(txx9_imclk);
@@ -231,7 +150,7 @@ exit:
 
 static int __exit txx9wdt_remove(struct platform_device *dev)
 {
-        misc_deregister(&txx9wdt_miscdev);
+        watchdog_unregister_device(&txx9wdt);
         clk_disable(txx9_imclk);
         clk_put(txx9_imclk);
         return 0;
@@ -239,7 +158,7 @@ static int __exit txx9wdt_remove(struct platform_device *dev)
 
 static void txx9wdt_shutdown(struct platform_device *dev)
 {
-        txx9wdt_stop();
+        txx9wdt_stop(&txx9wdt);
 }
 
 static struct platform_driver txx9wdt_driver = {