watchdog: coh901327: convert to use watchdog core

This converts the COH901327 watchdog to use the watchdog core.
I followed Wolframs document, looked at some other drivers and
tested it on the U300.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

2 files changed, 56 insertions, 137 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 7a8895396ecd..e25a4646672a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -287,6 +287,7 @@ config COH901327_WATCHDOG
         bool "ST-Ericsson COH 901 327 watchdog"
         depends on ARCH_U300
         default y if MACH_U300
+        select WATCHDOG_CORE
         help
           Say Y here to include Watchdog timer support for the
           watchdog embedded into the ST-Ericsson U300 series platforms.
diff --git a/drivers/watchdog/coh901327_wdt.c b/drivers/watchdog/coh901327_wdt.c
index 5b89f7d6cd0f..7f0cbeb58770 100644
--- a/drivers/watchdog/coh901327_wdt.c
+++ b/drivers/watchdog/coh901327_wdt.c
@@ -8,17 +8,15 @@
  */
 #include <linux/module.h>
 #include <linux/types.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/interrupt.h>
 #include <linux/pm.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/bitops.h>
-#include <linux/uaccess.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/err.h>
 
 #define DRV_NAME "WDOG COH 901 327"
 
@@ -74,8 +72,6 @@ static resource_size_t phybase;
 static resource_size_t physize;
 static int irq;
 static void __iomem *virtbase;
-static unsigned long coh901327_users;
-static unsigned long boot_status;
 static struct device *parent;
 
 /*
@@ -155,30 +151,31 @@ static void coh901327_disable(void)
                         __func__, val);
 }
 
-static void coh901327_start(void)
+static int coh901327_start(struct watchdog_device *wdt_dev)
 {
         coh901327_enable(margin * 100);
+        return 0;
+}
+
+static int coh901327_stop(struct watchdog_device *wdt_dev)
+{
+        coh901327_disable();
+        return 0;
 }
 
-static void coh901327_keepalive(void)
+static int coh901327_ping(struct watchdog_device *wdd)
 {
         clk_enable(clk);
         /* Feed the watchdog */
         writew(U300_WDOG_FR_FEED_RESTART_TIMER,
                virtbase + U300_WDOG_FR);
         clk_disable(clk);
+        return 0;
 }
 
-static int coh901327_settimeout(int time)
+static int coh901327_settimeout(struct watchdog_device *wdt_dev,
+                                unsigned int time)
 {
-        /*
-         * Max margin is 327 since the 10ms
-         * timeout register is max
-         * 0x7FFF = 327670ms ~= 327s.
-         */
-        if (time <= 0 || time > 327)
-                return -EINVAL;
-
         margin = time;
         clk_enable(clk);
         /* Set new timeout value */
@@ -190,6 +187,23 @@ static int coh901327_settimeout(int time)
         return 0;
 }
 
+static unsigned int coh901327_gettimeleft(struct watchdog_device *wdt_dev)
+{
+        u16 val;
+
+        clk_enable(clk);
+        /* Read repeatedly until the value is stable! */
+        val = readw(virtbase + U300_WDOG_CR);
+        while (val & U300_WDOG_CR_VALID_IND)
+                val = readw(virtbase + U300_WDOG_CR);
+        val &= U300_WDOG_CR_COUNT_VALUE_MASK;
+        clk_disable(clk);
+        if (val != 0)
+                val /= 100;
+
+        return val;
+}
+
 /*
  * This interrupt occurs 10 ms before the watchdog WILL bark.
  */
@@ -218,130 +232,35 @@ static irqreturn_t coh901327_interrupt(int irq, void *data)
         return IRQ_HANDLED;
 }
 
-/*
- * Allow only one user (daemon) to open the watchdog
- */
-static int coh901327_open(struct inode *inode, struct file *file)
-{
-        if (test_and_set_bit(1, &coh901327_users))
-                return -EBUSY;
-        coh901327_start();
-        return nonseekable_open(inode, file);
-}
-
-static int coh901327_release(struct inode *inode, struct file *file)
-{
-        clear_bit(1, &coh901327_users);
-        coh901327_disable();
-        return 0;
-}
-
-static ssize_t coh901327_write(struct file *file, const char __user *data,
-                               size_t len, loff_t *ppos)
-{
-        if (len)
-                coh901327_keepalive();
-        return len;
-}
-
-static long coh901327_ioctl(struct file *file, unsigned int cmd,
-                            unsigned long arg)
-{
-        int ret = -ENOTTY;
-        u16 val;
-        int time;
-        int new_options;
-        union {
-                struct watchdog_info __user *ident;
-                int __user *i;
-        } uarg;
-        static const struct watchdog_info ident = {
-                .options                = WDIOF_CARDRESET |
-                                          WDIOF_SETTIMEOUT |
-                                          WDIOF_KEEPALIVEPING,
-                .identity               = "COH 901 327 Watchdog",
-                .firmware_version       = 1,
-        };
-        uarg.i = (int __user *)arg;
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                ret = copy_to_user(uarg.ident, &ident,
-                                   sizeof(ident)) ? -EFAULT : 0;
-                break;
-
-        case WDIOC_GETSTATUS:
-                ret = put_user(0, uarg.i);
-                break;
-
-        case WDIOC_GETBOOTSTATUS:
-                ret = put_user(boot_status, uarg.i);
-                break;
-
-        case WDIOC_SETOPTIONS:
-                ret = get_user(new_options, uarg.i);
-                if (ret)
-                        break;
-                if (new_options & WDIOS_DISABLECARD)
-                        coh901327_disable();
-                if (new_options & WDIOS_ENABLECARD)
-                        coh901327_start();
-                ret = 0;
-                break;
-
-        case WDIOC_KEEPALIVE:
-                coh901327_keepalive();
-                ret = 0;
-                break;
-
-        case WDIOC_SETTIMEOUT:
-                ret = get_user(time, uarg.i);
-                if (ret)
-                        break;
-
-                ret = coh901327_settimeout(time);
-                if (ret)
-                        break;
-                /* Then fall through to return set value */
-
-        case WDIOC_GETTIMEOUT:
-                ret = put_user(margin, uarg.i);
-                break;
-
-        case WDIOC_GETTIMELEFT:
-                clk_enable(clk);
-                /* Read repeatedly until the value is stable! */
-                val = readw(virtbase + U300_WDOG_CR);
-                while (val & U300_WDOG_CR_VALID_IND)
-                        val = readw(virtbase + U300_WDOG_CR);
-                val &= U300_WDOG_CR_COUNT_VALUE_MASK;
-                clk_disable(clk);
-                if (val != 0)
-                        val /= 100;
-                ret = put_user(val, uarg.i);
-                break;
-        }
-        return ret;
-}
+static const struct watchdog_info coh901327_ident = {
+        .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+        .identity = DRV_NAME,
+};
 
-static const struct file_operations coh901327_fops = {
-        .owner          = THIS_MODULE,
-        .llseek         = no_llseek,
-        .write          = coh901327_write,
-        .unlocked_ioctl = coh901327_ioctl,
-        .open           = coh901327_open,
-        .release        = coh901327_release,
+static struct watchdog_ops coh901327_ops = {
+        .owner = THIS_MODULE,
+        .start = coh901327_start,
+        .stop = coh901327_stop,
+        .ping = coh901327_ping,
+        .set_timeout = coh901327_settimeout,
+        .get_timeleft = coh901327_gettimeleft,
 };
 
-static struct miscdevice coh901327_miscdev = {
-        .minor          = WATCHDOG_MINOR,
-        .name           = "watchdog",
-        .fops           = &coh901327_fops,
+static struct watchdog_device coh901327_wdt = {
+        .info = &coh901327_ident,
+        .ops = &coh901327_ops,
+        /*
+         * Max margin is 327 since the 10ms
+         * timeout register is max
+         * 0x7FFF = 327670ms ~= 327s.
+         */
+        .min_timeout = 0,
+        .max_timeout = 327,
 };
 
 static int __exit coh901327_remove(struct platform_device *pdev)
 {
-        misc_deregister(&coh901327_miscdev);
+        watchdog_unregister_device(&coh901327_wdt);
         coh901327_disable();
         free_irq(irq, pdev);
         clk_put(clk);
@@ -350,7 +269,6 @@ static int __exit coh901327_remove(struct platform_device *pdev)
         return 0;
 }
 
-
 static int __init coh901327_probe(struct platform_device *pdev)
 {
         int ret;
@@ -393,7 +311,7 @@ static int __init coh901327_probe(struct platform_device *pdev)
         case U300_WDOG_SR_STATUS_TIMED_OUT:
                 dev_info(&pdev->dev,
                         "watchdog timed out since last chip reset!\n");
-                boot_status = WDIOF_CARDRESET;
+                coh901327_wdt.bootstatus |= WDIOF_CARDRESET;
                 /* Status will be cleared below */
                 break;
         case U300_WDOG_SR_STATUS_NORMAL:
@@ -435,7 +353,7 @@ static int __init coh901327_probe(struct platform_device *pdev)
 
         clk_disable(clk);
 
-        ret = misc_register(&coh901327_miscdev);
+        ret = watchdog_register_device(&coh901327_wdt);
         if (ret == 0)
                 dev_info(&pdev->dev,
                          "initialized. timer margin=%d sec\n", margin);
@@ -547,4 +465,4 @@ module_param(margin, int, 0);
 MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
 
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:coh901327-watchdog");