watchdog: Convert jz4740_wdt driver to watchdog core

This patch converts jz4740_wdt driver to use watchdog core APIs.
Also use devm_* APIs to save a few error handling code.

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

1 files changed, 89 insertions, 175 deletions

diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
index 17ef300bccc5..28af416c3fbf 100644
--- a/drivers/watchdog/jz4740_wdt.c
+++ b/drivers/watchdog/jz4740_wdt.c
@@ -17,18 +17,15 @@
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/init.h>
-#include <linux/bitops.h>
 #include <linux/platform_device.h>
-#include <linux/spinlock.h>
-#include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/device.h>
 #include <linux/clk.h>
 #include <linux/slab.h>
+#include <linux/err.h>
 
 #include <asm/mach-jz4740/timer.h>
 
@@ -41,9 +38,6 @@
 #define JZ_WDT_CLOCK_RTC  0x2
 #define JZ_WDT_CLOCK_EXT  0x4
 
-#define WDT_IN_USE        0
-#define WDT_OK_TO_CLOSE   1
-
 #define JZ_WDT_CLOCK_DIV_SHIFT   3
 
 #define JZ_WDT_CLOCK_DIV_1    (0 << JZ_WDT_CLOCK_DIV_SHIFT)
@@ -56,32 +50,44 @@
 #define DEFAULT_HEARTBEAT 5
 #define MAX_HEARTBEAT     2048
 
-static struct {
-        void __iomem *base;
-        struct resource *mem;
-        struct clk *rtc_clk;
-        unsigned long status;
-} jz4740_wdt;
+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 int heartbeat = DEFAULT_HEARTBEAT;
+static unsigned int heartbeat = DEFAULT_HEARTBEAT;
+module_param(heartbeat, uint, 0);
+MODULE_PARM_DESC(heartbeat,
+                "Watchdog heartbeat period in seconds from 1 to "
+                __MODULE_STRING(MAX_HEARTBEAT) ", default "
+                __MODULE_STRING(DEFAULT_HEARTBEAT));
 
+struct jz4740_wdt_drvdata {
+        struct watchdog_device wdt;
+        void __iomem *base;
+        struct clk *rtc_clk;
+};
 
-static void jz4740_wdt_service(void)
+static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
 {
-        writew(0x0, jz4740_wdt.base + JZ_REG_WDT_TIMER_COUNTER);
+        struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+        writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
+        return 0;
 }
 
-static void jz4740_wdt_set_heartbeat(int new_heartbeat)
+static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
+                                    unsigned int new_timeout)
 {
+        struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
         unsigned int rtc_clk_rate;
         unsigned int timeout_value;
         unsigned short clock_div = JZ_WDT_CLOCK_DIV_1;
 
-        heartbeat = new_heartbeat;
-
-        rtc_clk_rate = clk_get_rate(jz4740_wdt.rtc_clk);
+        rtc_clk_rate = clk_get_rate(drvdata->rtc_clk);
 
-        timeout_value = rtc_clk_rate * heartbeat;
+        timeout_value = rtc_clk_rate * new_timeout;
         while (timeout_value > 0xffff) {
                 if (clock_div == JZ_WDT_CLOCK_DIV_1024) {
                         /* Requested timeout too high;
@@ -93,199 +99,114 @@ static void jz4740_wdt_set_heartbeat(int new_heartbeat)
                 clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT);
         }
 
-        writeb(0x0, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE);
-        writew(clock_div, jz4740_wdt.base + JZ_REG_WDT_TIMER_CONTROL);
+        writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
+        writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
 
-        writew((u16)timeout_value, jz4740_wdt.base + JZ_REG_WDT_TIMER_DATA);
-        writew(0x0, jz4740_wdt.base + JZ_REG_WDT_TIMER_COUNTER);
+        writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA);
+        writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
         writew(clock_div | JZ_WDT_CLOCK_RTC,
-                jz4740_wdt.base + JZ_REG_WDT_TIMER_CONTROL);
+                drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
 
-        writeb(0x1, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE);
-}
+        writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
 
-static void jz4740_wdt_enable(void)
-{
-        jz4740_timer_enable_watchdog();
-        jz4740_wdt_set_heartbeat(heartbeat);
-}
-
-static void jz4740_wdt_disable(void)
-{
-        jz4740_timer_disable_watchdog();
-        writeb(0x0, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE);
+        return 0;
 }
 
-static int jz4740_wdt_open(struct inode *inode, struct file *file)
+static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
 {
-        if (test_and_set_bit(WDT_IN_USE, &jz4740_wdt.status))
-                return -EBUSY;
-
-        jz4740_wdt_enable();
+        jz4740_timer_enable_watchdog();
+        jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
 
-        return nonseekable_open(inode, file);
+        return 0;
 }
 
-static ssize_t jz4740_wdt_write(struct file *file, const char *data,
-                size_t len, loff_t *ppos)
+static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
 {
-        if (len) {
-                size_t i;
-
-                clear_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status);
-                for (i = 0; i != len; i++) {
-                        char c;
+        struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
 
-                        if (get_user(c, data + i))
-                                return -EFAULT;
-
-                        if (c == 'V')
-                                set_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status);
-                }
-                jz4740_wdt_service();
-        }
+        jz4740_timer_disable_watchdog();
+        writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
 
-        return len;
+        return 0;
 }
 
-static const struct watchdog_info ident = {
-        .options = WDIOF_KEEPALIVEPING,
+static const struct watchdog_info jz4740_wdt_info = {
+        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
         .identity = "jz4740 Watchdog",
 };
 
-static long jz4740_wdt_ioctl(struct file *file,
-                                        unsigned int cmd, unsigned long arg)
-{
-        int ret = -ENOTTY;
-        int heartbeat_seconds;
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                ret = copy_to_user((struct watchdog_info *)arg, &ident,
-                                sizeof(ident)) ? -EFAULT : 0;
-                break;
-
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                ret = put_user(0, (int *)arg);
-                break;
-
-        case WDIOC_KEEPALIVE:
-                jz4740_wdt_service();
-                return 0;
-
-        case WDIOC_SETTIMEOUT:
-                if (get_user(heartbeat_seconds, (int __user *)arg))
-                        return -EFAULT;
-
-                jz4740_wdt_set_heartbeat(heartbeat_seconds);
-                return 0;
-
-        case WDIOC_GETTIMEOUT:
-                return put_user(heartbeat, (int *)arg);
-
-        default:
-                break;
-        }
-
-        return ret;
-}
-
-static int jz4740_wdt_release(struct inode *inode, struct file *file)
-{
-        jz4740_wdt_service();
-
-        if (test_and_clear_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status))
-                jz4740_wdt_disable();
-
-        clear_bit(WDT_IN_USE, &jz4740_wdt.status);
-        return 0;
-}
-
-static const struct file_operations jz4740_wdt_fops = {
+static const struct watchdog_ops jz4740_wdt_ops = {
         .owner = THIS_MODULE,
-        .llseek = no_llseek,
-        .write = jz4740_wdt_write,
-        .unlocked_ioctl = jz4740_wdt_ioctl,
-        .open = jz4740_wdt_open,
-        .release = jz4740_wdt_release,
-};
-
-static struct miscdevice jz4740_wdt_miscdev = {
-        .minor = WATCHDOG_MINOR,
-        .name = "watchdog",
-        .fops = &jz4740_wdt_fops,
+        .start = jz4740_wdt_start,
+        .stop = jz4740_wdt_stop,
+        .ping = jz4740_wdt_ping,
+        .set_timeout = jz4740_wdt_set_timeout,
 };
 
 static int __devinit jz4740_wdt_probe(struct platform_device *pdev)
 {
-        int ret = 0, size;
-        struct resource *res;
-        struct device *dev = &pdev->dev;
-
-        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-        if (res == NULL) {
-                dev_err(dev, "failed to get memory region resource\n");
-                return -ENXIO;
+        struct jz4740_wdt_drvdata *drvdata;
+        struct watchdog_device *jz4740_wdt;
+        struct resource *res;
+        int ret;
+
+        drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata),
+                               GFP_KERNEL);
+        if (!drvdata) {
+                dev_err(&pdev->dev, "Unable to alloacate watchdog device\n");
+                return -ENOMEM;
         }
 
-        size = resource_size(res);
-        jz4740_wdt.mem = request_mem_region(res->start, size, pdev->name);
-        if (jz4740_wdt.mem == NULL) {
-                dev_err(dev, "failed to get memory region\n");
-                return -EBUSY;
-        }
+        if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
+                heartbeat = DEFAULT_HEARTBEAT;
 
-        jz4740_wdt.base = ioremap_nocache(res->start, size);
-        if (jz4740_wdt.base == NULL) {
-                dev_err(dev, "failed to map memory region\n");
+        jz4740_wdt = &drvdata->wdt;
+        jz4740_wdt->info = &jz4740_wdt_info;
+        jz4740_wdt->ops = &jz4740_wdt_ops;
+        jz4740_wdt->timeout = heartbeat;
+        jz4740_wdt->min_timeout = 1;
+        jz4740_wdt->max_timeout = MAX_HEARTBEAT;
+        watchdog_set_nowayout(jz4740_wdt, nowayout);
+        watchdog_set_drvdata(jz4740_wdt, drvdata);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        drvdata->base = devm_request_and_ioremap(&pdev->dev, res);
+        if (drvdata->base == NULL) {
                 ret = -EBUSY;
-                goto err_release_region;
+                goto err_out;
         }
 
-        jz4740_wdt.rtc_clk = clk_get(NULL, "rtc");
-        if (IS_ERR(jz4740_wdt.rtc_clk)) {
-                dev_err(dev, "cannot find RTC clock\n");
-                ret = PTR_ERR(jz4740_wdt.rtc_clk);
-                goto err_iounmap;
+        drvdata->rtc_clk = clk_get(NULL, "rtc");
+        if (IS_ERR(drvdata->rtc_clk)) {
+                dev_err(&pdev->dev, "cannot find RTC clock\n");
+                ret = PTR_ERR(drvdata->rtc_clk);
+                goto err_out;
         }
 
-        ret = misc_register(&jz4740_wdt_miscdev);
-        if (ret < 0) {
-                dev_err(dev, "cannot register misc device\n");
+        ret = watchdog_register_device(&drvdata->wdt);
+        if (ret < 0)
                 goto err_disable_clk;
-        }
 
+        platform_set_drvdata(pdev, drvdata);
         return 0;
 
 err_disable_clk:
-        clk_put(jz4740_wdt.rtc_clk);
-err_iounmap:
-        iounmap(jz4740_wdt.base);
-err_release_region:
-        release_mem_region(jz4740_wdt.mem->start,
-                        resource_size(jz4740_wdt.mem));
+        clk_put(drvdata->rtc_clk);
+err_out:
         return ret;
 }
 
-
 static int __devexit jz4740_wdt_remove(struct platform_device *pdev)
 {
-        jz4740_wdt_disable();
-        misc_deregister(&jz4740_wdt_miscdev);
-        clk_put(jz4740_wdt.rtc_clk);
+        struct jz4740_wdt_drvdata *drvdata = platform_get_drvdata(pdev);
 
-        iounmap(jz4740_wdt.base);
-        jz4740_wdt.base = NULL;
-
-        release_mem_region(jz4740_wdt.mem->start,
-                                resource_size(jz4740_wdt.mem));
-        jz4740_wdt.mem = NULL;
+        jz4740_wdt_stop(&drvdata->wdt);
+        watchdog_unregister_device(&drvdata->wdt);
+        clk_put(drvdata->rtc_clk);
 
         return 0;
 }
 
-
 static struct platform_driver jz4740_wdt_driver = {
         .probe = jz4740_wdt_probe,
         .remove = __devexit_p(jz4740_wdt_remove),
@@ -299,13 +220,6 @@ module_platform_driver(jz4740_wdt_driver);
 
 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
 MODULE_DESCRIPTION("jz4740 Watchdog Driver");
-
-module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat,
-                "Watchdog heartbeat period in seconds from 1 to "
-                __MODULE_STRING(MAX_HEARTBEAT) ", default "
-                __MODULE_STRING(DEFAULT_HEARTBEAT));
-
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 MODULE_ALIAS("platform:jz4740-wdt");