watchdog: Convert jz4740_wdt driver to watchdog core
authorAxel Lin <axel.lin@gmail.com>
Thu, 26 Jan 2012 10:10:45 +0000 (18:10 +0800)
committerWim Van Sebroeck <wim@iguana.be>
Tue, 27 Mar 2012 18:06:16 +0000 (20:06 +0200)
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>
drivers/watchdog/Kconfig
drivers/watchdog/jz4740_wdt.c

index 7e9e8f4d8f0ccba1582ab9413831d9d8269c45ee..d5531fb46325fadb5e92e4ec2a89ce6ffff07705 100644 (file)
@@ -955,6 +955,7 @@ config INDYDOG
 config JZ4740_WDT
        tristate "Ingenic jz4740 SoC hardware watchdog"
        depends on MACH_JZ4740
+       select WATCHDOG_CORE
        help
          Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs.
 
index 17ef300bccc52ca6e8c78edd1f0cc391f2504147..28af416c3fbf34eae07d4e9951cf10a6e78ca75c 100644 (file)
 #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)
 #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");