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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>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Axel Lin authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent 86a1e18 commit 85f6df1
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Showing 2 changed files with 90 additions and 175 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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.

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264 changes: 89 additions & 175 deletions drivers/watchdog/jz4740_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>

Expand All @@ -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)
Expand All @@ -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;
Expand All @@ -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),
Expand All @@ -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");

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