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Subject[RFC][PATCH] watchdog: Convert jz4740_wdt driver to watchdog core
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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>
---
Hi Paul and Lars,
I don't have this hardware handy.
I'd appreciate if you can review and test this patch.

Thanks,
Axel

drivers/watchdog/Kconfig | 1 +
drivers/watchdog/jz4740_wdt.c | 250 ++++++++++++++---------------------------
2 files changed, 86 insertions(+), 165 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 877b107..32d48b8 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -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.

diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
index 17ef300..2cdb67f 100644
--- a/drivers/watchdog/jz4740_wdt.c
+++ b/drivers/watchdog/jz4740_wdt.c
@@ -17,11 +17,9 @@
#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>
@@ -29,6 +27,7 @@
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/slab.h>
+#include <linux/err.h>

#include <asm/mach-jz4740/timer.h>

@@ -56,30 +55,45 @@
#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 int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int heartbeat = DEFAULT_HEARTBEAT;
+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));

+struct jz4740_wdt_drvdata {
+ struct watchdog_device wdt;
+ void __iomem *base;
+ struct resource *mem;
+ 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_heartbeat(struct watchdog_device *wdt_dev,
+ unsigned int new_heartbeat)
{
+ 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;
while (timeout_value > 0xffff) {
@@ -93,199 +107,112 @@ 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);
-
- writeb(0x1, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE);
-}
+ drvdata->base + JZ_REG_WDT_TIMER_CONTROL);

-static void jz4740_wdt_enable(void)
-{
- jz4740_timer_enable_watchdog();
- jz4740_wdt_set_heartbeat(heartbeat);
-}
+ writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);

-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_heartbeat(wdt_dev, heartbeat);

- 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_heartbeat,
};

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;
+ 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;
+ jz4740_wdt = &drvdata->wdt;
+ jz4740_wdt->info = &jz4740_wdt_info;
+ jz4740_wdt->ops = &jz4740_wdt_ops;
+ watchdog_set_nowayout(jz4740_wdt, nowayout);
+ watchdog_set_drvdata(jz4740_wdt, drvdata);
+
+ drvdata->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (drvdata->mem == NULL) {
+ dev_err(&pdev->dev, "failed to get memory region resource\n");
+ return -ENXIO;
}

- jz4740_wdt.base = ioremap_nocache(res->start, size);
- if (jz4740_wdt.base == NULL) {
- dev_err(dev, "failed to map memory region\n");
+ drvdata->base = devm_request_and_ioremap(&pdev->dev, drvdata->mem);
+ 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);
-
- iounmap(jz4740_wdt.base);
- jz4740_wdt.base = NULL;
+ struct jz4740_wdt_drvdata *drvdata = platform_get_drvdata(pdev);

- 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 +226,6 @@ 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");
--
1.7.5.4




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