openwrt/target/linux/cns3xxx/patches-2.6.31/209-cns3xxx_watchdog_suppor...

497 lines
12 KiB
Diff

--- /dev/null
+++ b/drivers/watchdog/cns3xxx_wdt.c
@@ -0,0 +1,465 @@
+/*******************************************************************************
+ *
+ * drivers/watchdog/cns3xxx_wdt.c
+ *
+ * Watchdog timer driver for the CNS3XXX SOCs
+ *
+ * Author: Scott Shu
+ *
+ * Copyright (c) 2008 Cavium Networks
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, Version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
+ * NONINFRINGEMENT. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or
+ * visit http://www.gnu.org/licenses/.
+ *
+ * This file may also be available under a different license from Cavium.
+ * Contact Cavium Networks for more information
+ *
+ ******************************************************************************/
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <asm/hardware/arm_twd.h>
+
+struct cns3xxx_wdt {
+ unsigned long timer_alive;
+ struct device *dev;
+ void __iomem *base;
+ int irq;
+ unsigned int perturb;
+ char expect_close;
+};
+
+static struct platform_device *cns3xxx_wdt_dev;
+extern unsigned int twd_timer_rate;
+static spinlock_t wdt_lock;
+
+#define TIMER_MARGIN 60
+static int cns3xxx_margin = TIMER_MARGIN;
+module_param(cns3xxx_margin, int, 0);
+MODULE_PARM_DESC(cns3xxx_margin,
+ "CNS3XXX timer margin in seconds. (0 < cns3xxx_margin < 65536, default="
+ __MODULE_STRING(TIMER_MARGIN) ")");
+
+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) ")");
+
+#define ONLY_TESTING 0
+static int cns3xxx_noboot = ONLY_TESTING;
+module_param(cns3xxx_noboot, int, 0);
+MODULE_PARM_DESC(cns3xxx_noboot, "CNS3XXX watchdog action, "
+ "set to 1 to ignore reboots, 0 to reboot (default="
+ __MODULE_STRING(ONLY_TESTING) ")");
+
+/*
+ * This is the interrupt handler. Note that we only use this
+ * in testing mode, so don't actually do a reboot here.
+ */
+static irqreturn_t cns3xxx_wdt_fire(int irq, void *arg)
+{
+ struct cns3xxx_wdt *wdt = arg;
+
+ /* Check it really was our interrupt */
+ if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
+ dev_printk(KERN_CRIT, wdt->dev,
+ "Triggered - Reboot ignored.\n");
+ /* Clear the interrupt on the watchdog */
+ writel(1, wdt->base + TWD_WDOG_INTSTAT);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+/*
+ * cns3xxx_wdt_keepalive - reload the timer
+ *
+ * Note that the spec says a DIFFERENT value must be written to the reload
+ * register each time. The "perturb" variable deals with this by adding 1
+ * to the count every other time the function is called.
+ */
+static void cns3xxx_wdt_keepalive(struct cns3xxx_wdt *wdt)
+{
+ unsigned int count;
+
+ /* Assume prescale is set to 256 */
+ count = (twd_timer_rate / 256) * cns3xxx_margin;
+
+ /* Reload the counter */
+ spin_lock(&wdt_lock);
+ writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
+ wdt->perturb = wdt->perturb ? 0 : 1;
+ spin_unlock(&wdt_lock);
+}
+
+static void cns3xxx_wdt_stop(struct cns3xxx_wdt *wdt)
+{
+ spin_lock(&wdt_lock);
+ writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
+ writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
+ writel(0x0, wdt->base + TWD_WDOG_CONTROL);
+ spin_unlock(&wdt_lock);
+}
+
+static void cns3xxx_wdt_start(struct cns3xxx_wdt *wdt)
+{
+ dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
+
+ //spin_lock(&wdt_lock);
+ /* This loads the count register but does NOT start the count yet */
+ cns3xxx_wdt_keepalive(wdt);
+ spin_lock(&wdt_lock);
+
+ if (cns3xxx_noboot) {
+ /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
+ writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
+ } else {
+ /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
+ writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
+ }
+ spin_unlock(&wdt_lock);
+}
+
+static int cns3xxx_wdt_set_heartbeat(int t)
+{
+ if (t < 0x0001 || t > 0xFFFF)
+ return -EINVAL;
+
+ cns3xxx_margin = t;
+ return 0;
+}
+
+/*
+ * /dev/watchdog handling
+ */
+static int cns3xxx_wdt_open(struct inode *inode, struct file *file)
+{
+ struct cns3xxx_wdt *wdt = platform_get_drvdata(cns3xxx_wdt_dev);
+
+ if (test_and_set_bit(0, &wdt->timer_alive))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ file->private_data = wdt;
+
+ /*
+ * Activate timer
+ */
+ cns3xxx_wdt_start(wdt);
+
+ return nonseekable_open(inode, file);
+}
+
+static int cns3xxx_wdt_release(struct inode *inode, struct file *file)
+{
+ struct cns3xxx_wdt *wdt = file->private_data;
+
+ /*
+ * Shut off the timer.
+ * Lock it in if it's a module and we set nowayout
+ */
+ if (wdt->expect_close == 42)
+ cns3xxx_wdt_stop(wdt);
+ else {
+ dev_printk(KERN_CRIT, wdt->dev,
+ "unexpected close, not stopping watchdog!\n");
+ cns3xxx_wdt_keepalive(wdt);
+ }
+ clear_bit(0, &wdt->timer_alive);
+ wdt->expect_close = 0;
+ return 0;
+}
+
+static ssize_t cns3xxx_wdt_write(struct file *file, const char *data,
+ size_t len, loff_t *ppos)
+{
+ struct cns3xxx_wdt *wdt = file->private_data;
+
+ /*
+ * Refresh the timer.
+ */
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* In case it was set long ago */
+ wdt->expect_close = 0;
+
+ for (i = 0; i != len; i++) {
+ char c;
+
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ wdt->expect_close = 42;
+ }
+ }
+ cns3xxx_wdt_keepalive(wdt);
+ }
+ return len;
+}
+
+static struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ .identity = "CNS3XXX Watchdog",
+};
+
+static long cns3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct cns3xxx_wdt *wdt = file->private_data;
+ int ret;
+ union {
+ struct watchdog_info ident;
+ int i;
+ } uarg;
+
+ if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
+ return -ENOTTY;
+
+ if (_IOC_DIR(cmd) & _IOC_WRITE) {
+ ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
+ if (ret)
+ return -EFAULT;
+ }
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ uarg.ident = ident;
+ ret = 0;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ uarg.i = 0;
+ ret = 0;
+ break;
+
+ case WDIOC_SETOPTIONS:
+ ret = -EINVAL;
+ if (uarg.i & WDIOS_DISABLECARD) {
+ cns3xxx_wdt_stop(wdt);
+ ret = 0;
+ }
+ if (uarg.i & WDIOS_ENABLECARD) {
+ cns3xxx_wdt_start(wdt);
+ ret = 0;
+ }
+ break;
+
+ case WDIOC_KEEPALIVE:
+ cns3xxx_wdt_keepalive(wdt);
+ ret = 0;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ ret = cns3xxx_wdt_set_heartbeat(uarg.i);
+ if (ret)
+ break;
+
+ cns3xxx_wdt_keepalive(wdt);
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ uarg.i = cns3xxx_margin;
+ ret = 0;
+ break;
+
+ default:
+ return -ENOTTY;
+ }
+
+ if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
+ ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
+ if (ret)
+ ret = -EFAULT;
+ }
+ return ret;
+}
+
+/*
+ * System shutdown handler. Turn off the watchdog if we're
+ * restarting or halting the system.
+ */
+static void cns3xxx_wdt_shutdown(struct platform_device *dev)
+{
+ struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
+
+ if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
+ cns3xxx_wdt_stop(wdt);
+}
+
+/*
+ * Kernel Interfaces
+ */
+static const struct file_operations cns3xxx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = cns3xxx_wdt_write,
+ .unlocked_ioctl = cns3xxx_wdt_ioctl,
+ .open = cns3xxx_wdt_open,
+ .release = cns3xxx_wdt_release,
+};
+
+static struct miscdevice cns3xxx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &cns3xxx_wdt_fops,
+};
+
+static int __devinit cns3xxx_wdt_probe(struct platform_device *dev)
+{
+ struct cns3xxx_wdt *wdt;
+ struct resource *res;
+ int ret;
+
+ /* We only accept one device, and it must have an id of -1 */
+ if (dev->id != -1)
+ return -ENODEV;
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res) {
+ ret = -ENODEV;
+ goto err_out;
+ }
+
+ wdt = kzalloc(sizeof(struct cns3xxx_wdt), GFP_KERNEL);
+ if (!wdt) {
+ ret = -ENOMEM;
+ goto err_out;
+ }
+
+ wdt->dev = &dev->dev;
+ wdt->irq = platform_get_irq(dev, 0);
+ if (wdt->irq < 0) {
+ ret = -ENXIO;
+ goto err_free;
+ }
+ wdt->base = ioremap(res->start, res->end - res->start + 1);
+ if (!wdt->base) {
+ ret = -ENOMEM;
+ goto err_free;
+ }
+
+ cns3xxx_wdt_miscdev.parent = &dev->dev;
+ ret = misc_register(&cns3xxx_wdt_miscdev);
+ if (ret) {
+ dev_printk(KERN_ERR, wdt->dev,
+ "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto err_misc;
+ }
+
+ ret = request_irq(wdt->irq, cns3xxx_wdt_fire, IRQF_DISABLED,
+ dev->name, wdt);
+ if (ret) {
+ dev_printk(KERN_ERR, wdt->dev,
+ "cannot register IRQ%d for watchdog\n", wdt->irq);
+ goto err_irq;
+ }
+
+ cns3xxx_wdt_stop(wdt);
+ platform_set_drvdata(dev, wdt);
+ cns3xxx_wdt_dev = dev;
+
+ return 0;
+
+err_irq:
+ misc_deregister(&cns3xxx_wdt_miscdev);
+err_misc:
+ platform_set_drvdata(dev, NULL);
+ iounmap(wdt->base);
+err_free:
+ kfree(wdt);
+err_out:
+ return ret;
+}
+
+static int __devexit cns3xxx_wdt_remove(struct platform_device *dev)
+{
+ struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
+
+ platform_set_drvdata(dev, NULL);
+
+ misc_deregister(&cns3xxx_wdt_miscdev);
+
+ cns3xxx_wdt_dev = NULL;
+
+ free_irq(wdt->irq, wdt);
+ iounmap(wdt->base);
+ kfree(wdt);
+ return 0;
+}
+
+
+static struct platform_driver cns3xxx_wdt_driver = {
+ .probe = cns3xxx_wdt_probe,
+ .remove = __devexit_p(cns3xxx_wdt_remove),
+ .shutdown = cns3xxx_wdt_shutdown,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "cns3xxx-wdt",
+ },
+};
+
+static char banner[] __initdata = KERN_INFO
+ "CNS3XXX Watchdog Timer, noboot=%d margin=%d sec (nowayout= %d)\n";
+
+static int __init cns3xxx_wdt_init(void)
+{
+ /*
+ * Check that the margin value is within it's range;
+ * if not reset to the default
+ */
+ if (cns3xxx_wdt_set_heartbeat(cns3xxx_margin)) {
+ cns3xxx_wdt_set_heartbeat(TIMER_MARGIN);
+ printk(KERN_INFO "cns3xxx_margin value must be 0 < cns3xxx_margin < 65536, using %d\n",
+ TIMER_MARGIN);
+ }
+
+ printk(banner, cns3xxx_noboot, cns3xxx_margin, nowayout);
+
+ spin_lock_init(&wdt_lock);
+
+ return platform_driver_register(&cns3xxx_wdt_driver);
+}
+
+static void __exit cns3xxx_wdt_exit(void)
+{
+ platform_driver_unregister(&cns3xxx_wdt_driver);
+}
+
+module_init(cns3xxx_wdt_init);
+module_exit(cns3xxx_wdt_exit);
+
+MODULE_AUTHOR("Scott Shu");
+MODULE_DESCRIPTION("CNS3XXX Watchdog Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:cns3xxx-wdt");
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -231,6 +231,15 @@ config DAVINCI_WATCHDOG
NOTE: once enabled, this timer cannot be disabled.
Say N if you are unsure.
+config CNS3XXX_WATCHDOG
+ tristate "CNS3XXX watchdog"
+ depends on ARCH_CNS3XXX && LOCAL_TIMERS
+ help
+ Watchdog timer embedded into the CNS3XXX SoCs system.
+
+ To compile this driver as a module, choose M here: the
+ module will be called cns3xxx_wdt.
+
config ORION_WATCHDOG
tristate "Orion watchdog"
depends on ARCH_ORION5X || ARCH_KIRKWOOD
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_
obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
+obj-$(CONFIG_CNS3XXX_WATCHDOG) += cns3xxx_wdt.o
obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o