[PATCH v3 01/11] watchdog: xilinx: Convert driver to the watchdog framework

From: Michal Simek
Date: Wed Feb 12 2014 - 08:35:34 EST

- Remove uneeded headers, fops functions
- Use xilinx_wdt prefix in start/stop/keepalive functions
and in new structures

Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---

Changes in v3: None
Changes in v2: None

drivers/watchdog/Kconfig | 1 +
drivers/watchdog/of_xilinx_wdt.c | 204 ++++++---------------------------------
2 files changed, 33 insertions(+), 172 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 4c4c566..9db5d3c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1025,6 +1025,7 @@ config M54xx_WATCHDOG
config XILINX_WATCHDOG
tristate "Xilinx Watchdog timer"
depends on MICROBLAZE
+ select WATCHDOG_CORE
---help---
Watchdog driver for the xps_timebase_wdt ip core.

diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index fb57103..8c2814e 100644
--- a/drivers/watchdog/of_xilinx_wdt.c
+++ b/drivers/watchdog/of_xilinx_wdt.c
@@ -1,6 +1,7 @@
/*
* Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
*
+ * (C) Copyright 2013 - 2014 Xilinx, Inc.
* (C) Copyright 2011 (Alejandro Cabrera <aldaya@xxxxxxxxx>)
*
* This program is free software; you can redistribute it and/or
@@ -14,13 +15,10 @@
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/io.h>
-#include <linux/uaccess.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
@@ -48,22 +46,18 @@
struct xwdt_device {
struct resource res;
void __iomem *base;
- u32 nowayout;
u32 wdt_interval;
- u32 boot_status;
};

static struct xwdt_device xdev;

static u32 timeout;
static u32 control_status_reg;
-static u8 expect_close;
static u8 no_timeout;
-static unsigned long driver_open;

static DEFINE_SPINLOCK(spinlock);

-static void xwdt_start(void)
+static int xilinx_wdt_start(struct watchdog_device *wdd)
{
spin_lock(&spinlock);

@@ -77,9 +71,11 @@ static void xwdt_start(void)
iowrite32(XWT_CSRX_EWDT2_MASK, xdev.base + XWT_TWCSR1_OFFSET);

spin_unlock(&spinlock);
+
+ return 0;
}

-static void xwdt_stop(void)
+static int xilinx_wdt_stop(struct watchdog_device *wdd)
{
spin_lock(&spinlock);

@@ -92,9 +88,11 @@ static void xwdt_stop(void)

spin_unlock(&spinlock);
pr_info("Stopped!\n");
+
+ return 0;
}

-static void xwdt_keepalive(void)
+static int xilinx_wdt_keepalive(struct watchdog_device *wdd)
{
spin_lock(&spinlock);

@@ -103,23 +101,28 @@ static void xwdt_keepalive(void)
iowrite32(control_status_reg, xdev.base + XWT_TWCSR0_OFFSET);

spin_unlock(&spinlock);
-}

-static void xwdt_get_status(int *status)
-{
- int new_status;
+ return 0;
+}

- spin_lock(&spinlock);
+static const struct watchdog_info xilinx_wdt_ident = {
+ .options = WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .firmware_version = 1,
+ .identity = WATCHDOG_NAME,
+};

- control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
- new_status = ((control_status_reg &
- (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK)) != 0);
- spin_unlock(&spinlock);
+static const struct watchdog_ops xilinx_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = xilinx_wdt_start,
+ .stop = xilinx_wdt_stop,
+ .ping = xilinx_wdt_keepalive,
+};

- *status = 0;
- if (new_status & 1)
- *status |= WDIOF_CARDRESET;
-}
+static struct watchdog_device xilinx_wdt_wdd = {
+ .info = &xilinx_wdt_ident,
+ .ops = &xilinx_wdt_ops,
+};

static u32 xwdt_selftest(void)
{
@@ -146,139 +149,6 @@ static u32 xwdt_selftest(void)
return XWT_TIMER_FAILED;
}

-static int xwdt_open(struct inode *inode, struct file *file)
-{
- /* Only one process can handle the wdt at a time */
- if (test_and_set_bit(0, &driver_open))
- return -EBUSY;
-
- /* Make sure that the module are always loaded...*/
- if (xdev.nowayout)
- __module_get(THIS_MODULE);
-
- xwdt_start();
- pr_info("Started...\n");
-
- return nonseekable_open(inode, file);
-}
-
-static int xwdt_release(struct inode *inode, struct file *file)
-{
- if (expect_close == 42) {
- xwdt_stop();
- } else {
- pr_crit("Unexpected close, not stopping watchdog!\n");
- xwdt_keepalive();
- }
-
- clear_bit(0, &driver_open);
- expect_close = 0;
- return 0;
-}
-
-/*
- * xwdt_write:
- * @file: file handle to the watchdog
- * @buf: buffer to write (unused as data does not matter here
- * @count: count of bytes
- * @ppos: pointer to the position to write. No seeks allowed
- *
- * A write to a watchdog device is defined as a keepalive signal. Any
- * write of data will do, as we don't define content meaning.
- */
-static ssize_t xwdt_write(struct file *file, const char __user *buf,
- size_t len, loff_t *ppos)
-{
- if (len) {
- if (!xdev.nowayout) {
- size_t i;
-
- /* In case it was set long ago */
- expect_close = 0;
-
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, buf + i))
- return -EFAULT;
- if (c == 'V')
- expect_close = 42;
- }
- }
- xwdt_keepalive();
- }
- return len;
-}
-
-static const struct watchdog_info ident = {
- .options = WDIOF_MAGICCLOSE |
- WDIOF_KEEPALIVEPING,
- .firmware_version = 1,
- .identity = WATCHDOG_NAME,
-};
-
-/*
- * xwdt_ioctl:
- * @file: file handle to the device
- * @cmd: watchdog command
- * @arg: argument pointer
- *
- * The watchdog API defines a common set of functions for all watchdogs
- * according to their available features.
- */
-static long xwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- int status;
-
- union {
- struct watchdog_info __user *ident;
- int __user *i;
- } uarg;
-
- uarg.i = (int __user *)arg;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- return copy_to_user(uarg.ident, &ident,
- sizeof(ident)) ? -EFAULT : 0;
-
- case WDIOC_GETBOOTSTATUS:
- return put_user(xdev.boot_status, uarg.i);
-
- case WDIOC_GETSTATUS:
- xwdt_get_status(&status);
- return put_user(status, uarg.i);
-
- case WDIOC_KEEPALIVE:
- xwdt_keepalive();
- return 0;
-
- case WDIOC_GETTIMEOUT:
- if (no_timeout)
- return -ENOTTY;
- else
- return put_user(timeout, uarg.i);
-
- default:
- return -ENOTTY;
- }
-}
-
-static const struct file_operations xwdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = xwdt_write,
- .open = xwdt_open,
- .release = xwdt_release,
- .unlocked_ioctl = xwdt_ioctl,
-};
-
-static struct miscdevice xwdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &xwdt_fops,
-};
-
static int xwdt_probe(struct platform_device *pdev)
{
int rc;
@@ -314,7 +184,7 @@ static int xwdt_probe(struct platform_device *pdev)
"xlnx,wdt-enable-once", NULL);
if (tmptr == NULL) {
pr_warn("Parameter \"xlnx,wdt-enable-once\" not found in device tree!\n");
- xdev.nowayout = WATCHDOG_NOWAYOUT;
+ watchdog_set_nowayout(&xilinx_wdt_wdd, true);
}

/*
@@ -344,24 +214,14 @@ static int xwdt_probe(struct platform_device *pdev)
goto unmap_io;
}

- xwdt_get_status(&xdev.boot_status);
-
- rc = misc_register(&xwdt_miscdev);
+ rc = watchdog_register_device(&xilinx_wdt_wdd);
if (rc) {
- pr_err("cannot register miscdev on minor=%d (err=%d)\n",
- xwdt_miscdev.minor, rc);
+ pr_err("cannot register watchdog (err=%d)\n", rc);
goto unmap_io;
}

- if (no_timeout)
- pr_info("driver loaded (timeout=? sec, nowayout=%d)\n",
- xdev.nowayout);
- else
- pr_info("driver loaded (timeout=%d sec, nowayout=%d)\n",
- timeout, xdev.nowayout);
-
- expect_close = 0;
- clear_bit(0, &driver_open);
+ dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
+ xdev.base, timeout);

return 0;

@@ -375,7 +235,7 @@ err_out:

static int xwdt_remove(struct platform_device *dev)
{
- misc_deregister(&xwdt_miscdev);
+ watchdog_unregister_device(&xilinx_wdt_wdd);
iounmap(xdev.base);
release_mem_region(xdev.res.start, resource_size(&xdev.res));

--
1.8.2.3

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