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path: root/drivers/watchdog/of_xilinx_wdt.c
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Diffstat (limited to 'drivers/watchdog/of_xilinx_wdt.c')
-rw-r--r--drivers/watchdog/of_xilinx_wdt.c390
1 files changed, 116 insertions, 274 deletions
diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index fb57103c8ebc..57ccae8327ff 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@gmail.com>)
*
* This program is free software; you can redistribute it and/or
@@ -9,18 +10,13 @@
* 2 of the License, or (at your option) any later version.
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
+#include <linux/err.h>
#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>
@@ -43,102 +39,103 @@
#define XWT_TIMER_FAILED 0xFFFFFFFF
#define WATCHDOG_NAME "Xilinx Watchdog"
-#define PFX WATCHDOG_NAME ": "
struct xwdt_device {
- struct resource res;
void __iomem *base;
- u32 nowayout;
u32 wdt_interval;
- u32 boot_status;
+ spinlock_t spinlock;
+ struct watchdog_device xilinx_wdt_wdd;
};
-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);
+ u32 control_status_reg;
+ struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
+
+ spin_lock(&xdev->spinlock);
/* Clean previous status and enable the watchdog timer */
- control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
+ control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
iowrite32((control_status_reg | XWT_CSR0_EWDT1_MASK),
- xdev.base + XWT_TWCSR0_OFFSET);
+ xdev->base + XWT_TWCSR0_OFFSET);
+
+ iowrite32(XWT_CSRX_EWDT2_MASK, xdev->base + XWT_TWCSR1_OFFSET);
- iowrite32(XWT_CSRX_EWDT2_MASK, xdev.base + XWT_TWCSR1_OFFSET);
+ spin_unlock(&xdev->spinlock);
- spin_unlock(&spinlock);
+ return 0;
}
-static void xwdt_stop(void)
+static int xilinx_wdt_stop(struct watchdog_device *wdd)
{
- spin_lock(&spinlock);
+ u32 control_status_reg;
+ struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
+
+ spin_lock(&xdev->spinlock);
- control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
+ control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
iowrite32((control_status_reg & ~XWT_CSR0_EWDT1_MASK),
- xdev.base + XWT_TWCSR0_OFFSET);
+ xdev->base + XWT_TWCSR0_OFFSET);
- iowrite32(0, xdev.base + XWT_TWCSR1_OFFSET);
+ iowrite32(0, xdev->base + XWT_TWCSR1_OFFSET);
- spin_unlock(&spinlock);
+ spin_unlock(&xdev->spinlock);
pr_info("Stopped!\n");
+
+ return 0;
}
-static void xwdt_keepalive(void)
+static int xilinx_wdt_keepalive(struct watchdog_device *wdd)
{
- spin_lock(&spinlock);
+ u32 control_status_reg;
+ struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
- control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
- control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
- iowrite32(control_status_reg, xdev.base + XWT_TWCSR0_OFFSET);
+ spin_lock(&xdev->spinlock);
- spin_unlock(&spinlock);
-}
+ control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
+ control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
+ iowrite32(control_status_reg, xdev->base + XWT_TWCSR0_OFFSET);
-static void xwdt_get_status(int *status)
-{
- int new_status;
+ spin_unlock(&xdev->spinlock);
- spin_lock(&spinlock);
+ return 0;
+}
- 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_info xilinx_wdt_ident = {
+ .options = WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .firmware_version = 1,
+ .identity = WATCHDOG_NAME,
+};
- *status = 0;
- if (new_status & 1)
- *status |= WDIOF_CARDRESET;
-}
+static const struct watchdog_ops xilinx_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = xilinx_wdt_start,
+ .stop = xilinx_wdt_stop,
+ .ping = xilinx_wdt_keepalive,
+};
-static u32 xwdt_selftest(void)
+static u32 xwdt_selftest(struct xwdt_device *xdev)
{
int i;
u32 timer_value1;
u32 timer_value2;
- spin_lock(&spinlock);
+ spin_lock(&xdev->spinlock);
- timer_value1 = ioread32(xdev.base + XWT_TBR_OFFSET);
- timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);
+ timer_value1 = ioread32(xdev->base + XWT_TBR_OFFSET);
+ timer_value2 = ioread32(xdev->base + XWT_TBR_OFFSET);
for (i = 0;
((i <= XWT_MAX_SELFTEST_LOOP_COUNT) &&
(timer_value2 == timer_value1)); i++) {
- timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);
+ timer_value2 = ioread32(xdev->base + XWT_TBR_OFFSET);
}
- spin_unlock(&spinlock);
+ spin_unlock(&xdev->spinlock);
if (timer_value2 != timer_value1)
return ~XWT_TIMER_FAILED;
@@ -146,238 +143,83 @@ 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;
- u32 *tmptr;
- u32 *pfreq;
-
- no_timeout = 0;
-
- pfreq = (u32 *)of_get_property(pdev->dev.of_node,
- "clock-frequency", NULL);
-
- if (pfreq == NULL) {
- pr_warn("The watchdog clock frequency cannot be obtained!\n");
- no_timeout = 1;
- }
-
- rc = of_address_to_resource(pdev->dev.of_node, 0, &xdev.res);
- if (rc) {
- pr_warn("invalid address!\n");
- return rc;
- }
-
- tmptr = (u32 *)of_get_property(pdev->dev.of_node,
- "xlnx,wdt-interval", NULL);
- if (tmptr == NULL) {
- pr_warn("Parameter \"xlnx,wdt-interval\" not found in device tree!\n");
- no_timeout = 1;
- } else {
- xdev.wdt_interval = *tmptr;
- }
-
- tmptr = (u32 *)of_get_property(pdev->dev.of_node,
- "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;
- }
-
-/*
- * Twice of the 2^wdt_interval / freq because the first wdt overflow is
- * ignored (interrupt), reset is only generated at second wdt overflow
- */
- if (!no_timeout)
- timeout = 2 * ((1<<xdev.wdt_interval) / *pfreq);
-
- if (!request_mem_region(xdev.res.start,
- xdev.res.end - xdev.res.start + 1, WATCHDOG_NAME)) {
- rc = -ENXIO;
- pr_err("memory request failure!\n");
- goto err_out;
- }
-
- xdev.base = ioremap(xdev.res.start, xdev.res.end - xdev.res.start + 1);
- if (xdev.base == NULL) {
- rc = -ENOMEM;
- pr_err("ioremap failure!\n");
- goto release_mem;
- }
-
- rc = xwdt_selftest();
+ u32 pfreq = 0, enable_once = 0;
+ struct resource *res;
+ struct xwdt_device *xdev;
+ struct watchdog_device *xilinx_wdt_wdd;
+
+ xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
+ if (!xdev)
+ return -ENOMEM;
+
+ xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
+ xilinx_wdt_wdd->info = &xilinx_wdt_ident;
+ xilinx_wdt_wdd->ops = &xilinx_wdt_ops;
+ xilinx_wdt_wdd->parent = &pdev->dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ xdev->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(xdev->base))
+ return PTR_ERR(xdev->base);
+
+ rc = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &pfreq);
+ if (rc)
+ dev_warn(&pdev->dev,
+ "The watchdog clock frequency cannot be obtained\n");
+
+ rc = of_property_read_u32(pdev->dev.of_node, "xlnx,wdt-interval",
+ &xdev->wdt_interval);
+ if (rc)
+ dev_warn(&pdev->dev,
+ "Parameter \"xlnx,wdt-interval\" not found\n");
+
+ rc = of_property_read_u32(pdev->dev.of_node, "xlnx,wdt-enable-once",
+ &enable_once);
+ if (rc)
+ dev_warn(&pdev->dev,
+ "Parameter \"xlnx,wdt-enable-once\" not found\n");
+
+ watchdog_set_nowayout(xilinx_wdt_wdd, enable_once);
+
+ /*
+ * Twice of the 2^wdt_interval / freq because the first wdt overflow is
+ * ignored (interrupt), reset is only generated at second wdt overflow
+ */
+ if (pfreq && xdev->wdt_interval)
+ xilinx_wdt_wdd->timeout = 2 * ((1 << xdev->wdt_interval) /
+ pfreq);
+
+ spin_lock_init(&xdev->spinlock);
+ watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
+
+ rc = xwdt_selftest(xdev);
if (rc == XWT_TIMER_FAILED) {
- pr_err("SelfTest routine error!\n");
- goto unmap_io;
+ dev_err(&pdev->dev, "SelfTest routine error\n");
+ return rc;
}
- 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);
- goto unmap_io;
+ dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n", rc);
+ return rc;
}
- 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);
+ dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
+ xdev->base, xilinx_wdt_wdd->timeout);
- expect_close = 0;
- clear_bit(0, &driver_open);
+ platform_set_drvdata(pdev, xdev);
return 0;
-
-unmap_io:
- iounmap(xdev.base);
-release_mem:
- release_mem_region(xdev.res.start, resource_size(&xdev.res));
-err_out:
- return rc;
}
-static int xwdt_remove(struct platform_device *dev)
+static int xwdt_remove(struct platform_device *pdev)
{
- misc_deregister(&xwdt_miscdev);
- iounmap(xdev.base);
- release_mem_region(xdev.res.start, resource_size(&xdev.res));
+ struct xwdt_device *xdev = platform_get_drvdata(pdev);
+
+ watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
return 0;
}