--- /dev/null
+/*
+ * linux/drivers/char/watchdog/omap_wdt.c
+ *
+ * Watchdog driver for the TI OMAP 16xx & 24xx 32KHz (non-secure) watchdog
+ *
+ * Author: MontaVista Software, Inc.
+ * <gdavis@mvista.com> or <source@mvista.com>
+ *
+ * 2003 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * History:
+ *
+ * 20030527: George G. Davis <gdavis@mvista.com>
+ * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
+ * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ * Based on SoftDog driver by Alan Cox <alan@redhat.com>
+ *
+ * Copyright (c) 2004 Texas Instruments.
+ * 1. Modified to support OMAP1610 32-KHz watchdog timer
+ * 2. Ported to 2.6 kernel
+ *
+ * Copyright (c) 2005 David Brownell
+ * Use the driver model and standard identifiers; handle bigger timeouts.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/moduleparam.h>
+#include <linux/clk.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/hardware.h>
+#include <asm/bitops.h>
+
+#include <asm/arch/prcm.h>
+
+#include "omap_wdt.h"
+
+static unsigned timer_margin;
+module_param(timer_margin, uint, 0);
+MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
+
+static int omap_wdt_users;
+static struct clk *armwdt_ck = NULL;
+static struct clk *mpu_wdt_ick = NULL;
+static struct clk *mpu_wdt_fck = NULL;
+
+static unsigned int wdt_trgr_pattern = 0x1234;
+
+static void omap_wdt_ping(void)
+{
+ /* wait for posted write to complete */
+ while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08)
+ cpu_relax();
+ wdt_trgr_pattern = ~wdt_trgr_pattern;
+ omap_writel(wdt_trgr_pattern, (OMAP_WATCHDOG_TGR));
+ /* wait for posted write to complete */
+ while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08)
+ cpu_relax();
+ /* reloaded WCRR from WLDR */
+}
+
+static void omap_wdt_enable(void)
+{
+ /* Sequence to enable the watchdog */
+ omap_writel(0xBBBB, OMAP_WATCHDOG_SPR);
+ while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10)
+ cpu_relax();
+ omap_writel(0x4444, OMAP_WATCHDOG_SPR);
+ while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10)
+ cpu_relax();
+}
+
+static void omap_wdt_disable(void)
+{
+ /* sequence required to disable watchdog */
+ omap_writel(0xAAAA, OMAP_WATCHDOG_SPR); /* TIMER_MODE */
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10)
+ cpu_relax();
+ omap_writel(0x5555, OMAP_WATCHDOG_SPR); /* TIMER_MODE */
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10)
+ cpu_relax();
+}
+
+static void omap_wdt_adjust_timeout(unsigned new_timeout)
+{
+ if (new_timeout < TIMER_MARGIN_MIN)
+ new_timeout = TIMER_MARGIN_DEFAULT;
+ if (new_timeout > TIMER_MARGIN_MAX)
+ new_timeout = TIMER_MARGIN_MAX;
+ timer_margin = new_timeout;
+}
+
+static void omap_wdt_set_timeout(void)
+{
+ u32 pre_margin = GET_WLDR_VAL(timer_margin);
+
+ /* just count up at 32 KHz */
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x04)
+ cpu_relax();
+ omap_writel(pre_margin, OMAP_WATCHDOG_LDR);
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x04)
+ cpu_relax();
+}
+
+/*
+ * Allow only one task to hold it open
+ */
+
+static int omap_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(1, (unsigned long *)&omap_wdt_users))
+ return -EBUSY;
+
+ if (cpu_is_omap16xx())
+ clk_enable(armwdt_ck); /* Enable the clock */
+
+ if (cpu_is_omap24xx()) {
+ clk_enable(mpu_wdt_ick); /* Enable the interface clock */
+ clk_enable(mpu_wdt_fck); /* Enable the functional clock */
+ }
+
+ /* initialize prescaler */
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x01)
+ cpu_relax();
+ omap_writel((1 << 5) | (PTV << 2), OMAP_WATCHDOG_CNTRL);
+ while (omap_readl(OMAP_WATCHDOG_WPS) & 0x01)
+ cpu_relax();
+
+ omap_wdt_set_timeout();
+ omap_wdt_enable();
+ return 0;
+}
+
+static int omap_wdt_release(struct inode *inode, struct file *file)
+{
+ /*
+ * Shut off the timer unless NOWAYOUT is defined.
+ */
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+ omap_wdt_disable();
+
+ if (cpu_is_omap16xx()) {
+ clk_disable(armwdt_ck); /* Disable the clock */
+ clk_put(armwdt_ck);
+ armwdt_ck = NULL;
+ }
+
+ if (cpu_is_omap24xx()) {
+ clk_disable(mpu_wdt_ick); /* Disable the clock */
+ clk_disable(mpu_wdt_fck); /* Disable the clock */
+ clk_put(mpu_wdt_ick);
+ clk_put(mpu_wdt_fck);
+ mpu_wdt_ick = NULL;
+ mpu_wdt_fck = NULL;
+ }
+#else
+ printk(KERN_CRIT "omap_wdt: Unexpected close, not stopping!\n");
+#endif
+ omap_wdt_users = 0;
+ return 0;
+}
+
+static ssize_t
+omap_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* Refresh LOAD_TIME. */
+ if (len)
+ omap_wdt_ping();
+ return len;
+}
+
+static int
+omap_wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int new_margin;
+ static struct watchdog_info ident = {
+ .identity = "OMAP Watchdog",
+ .options = WDIOF_SETTIMEOUT,
+ .firmware_version = 0,
+ };
+
+ switch (cmd) {
+ default:
+ return -ENOIOCTLCMD;
+ case WDIOC_GETSUPPORT:
+ return copy_to_user((struct watchdog_info __user *)arg, &ident,
+ sizeof(ident));
+ case WDIOC_GETSTATUS:
+ return put_user(0, (int __user *)arg);
+ case WDIOC_GETBOOTSTATUS:
+ if (cpu_is_omap16xx())
+ return put_user(omap_readw(ARM_SYSST),
+ (int __user *)arg);
+ if (cpu_is_omap24xx())
+ return put_user(omap_prcm_get_reset_sources(),
+ (int __user *)arg);
+ case WDIOC_KEEPALIVE:
+ omap_wdt_ping();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_margin, (int __user *)arg))
+ return -EFAULT;
+ omap_wdt_adjust_timeout(new_margin);
+
+ omap_wdt_disable();
+ omap_wdt_set_timeout();
+ omap_wdt_enable();
+
+ omap_wdt_ping();
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timer_margin, (int __user *)arg);
+ }
+}
+
+static struct file_operations omap_wdt_fops = {
+ .owner = THIS_MODULE,
+ .write = omap_wdt_write,
+ .ioctl = omap_wdt_ioctl,
+ .open = omap_wdt_open,
+ .release = omap_wdt_release,
+};
+
+static struct miscdevice omap_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &omap_wdt_fops
+};
+
+static int __init omap_wdt_probe(struct platform_device *pdev)
+{
+ struct resource *res, *mem;
+ int ret;
+
+ /* reserve static register mappings */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOENT;
+
+ mem = request_mem_region(res->start, res->end - res->start + 1,
+ pdev->name);
+ if (mem == NULL)
+ return -EBUSY;
+
+ platform_set_drvdata(pdev, mem);
+
+ omap_wdt_users = 0;
+
+ if (cpu_is_omap16xx()) {
+ armwdt_ck = clk_get(&pdev->dev, "armwdt_ck");
+ if (IS_ERR(armwdt_ck)) {
+ ret = PTR_ERR(armwdt_ck);
+ armwdt_ck = NULL;
+ goto fail;
+ }
+ }
+
+ if (cpu_is_omap24xx()) {
+ mpu_wdt_ick = clk_get(&pdev->dev, "mpu_wdt_ick");
+ if (IS_ERR(mpu_wdt_ick)) {
+ ret = PTR_ERR(mpu_wdt_ick);
+ mpu_wdt_ick = NULL;
+ goto fail;
+ }
+ mpu_wdt_fck = clk_get(&pdev->dev, "mpu_wdt_fck");
+ if (IS_ERR(mpu_wdt_fck)) {
+ ret = PTR_ERR(mpu_wdt_fck);
+ mpu_wdt_fck = NULL;
+ goto fail;
+ }
+ }
+
+ omap_wdt_disable();
+ omap_wdt_adjust_timeout(timer_margin);
+
+ omap_wdt_miscdev.parent = &pdev->dev;
+ ret = misc_register(&omap_wdt_miscdev);
+ if (ret)
+ goto fail;
+
+ pr_info("OMAP Watchdog Timer: initial timeout %d sec\n", timer_margin);
+
+ /* autogate OCP interface clock */
+ omap_writel(0x01, OMAP_WATCHDOG_SYS_CONFIG);
+ return 0;
+
+fail:
+ if (armwdt_ck)
+ clk_put(armwdt_ck);
+ if (mpu_wdt_ick)
+ clk_put(mpu_wdt_ick);
+ if (mpu_wdt_fck)
+ clk_put(mpu_wdt_fck);
+ release_resource(mem);
+ return ret;
+}
+
+static void omap_wdt_shutdown(struct platform_device *pdev)
+{
+ omap_wdt_disable();
+}
+
+static int omap_wdt_remove(struct platform_device *pdev)
+{
+ struct resource *mem = platform_get_drvdata(pdev);
+ misc_deregister(&omap_wdt_miscdev);
+ release_resource(mem);
+ if (armwdt_ck)
+ clk_put(armwdt_ck);
+ if (mpu_wdt_ick)
+ clk_put(mpu_wdt_ick);
+ if (mpu_wdt_fck)
+ clk_put(mpu_wdt_fck);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+/* REVISIT ... not clear this is the best way to handle system suspend; and
+ * it's very inappropriate for selective device suspend (e.g. suspending this
+ * through sysfs rather than by stopping the watchdog daemon). Also, this
+ * may not play well enough with NOWAYOUT...
+ */
+
+static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ if (omap_wdt_users)
+ omap_wdt_disable();
+ return 0;
+}
+
+static int omap_wdt_resume(struct platform_device *pdev)
+{
+ if (omap_wdt_users) {
+ omap_wdt_enable();
+ omap_wdt_ping();
+ }
+ return 0;
+}
+
+#else
+#define omap_wdt_suspend NULL
+#define omap_wdt_resume NULL
+#endif
+
+static struct platform_driver omap_wdt_driver = {
+ .probe = omap_wdt_probe,
+ .remove = omap_wdt_remove,
+ .shutdown = omap_wdt_shutdown,
+ .suspend = omap_wdt_suspend,
+ .resume = omap_wdt_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "omap_wdt",
+ },
+};
+
+static int __init omap_wdt_init(void)
+{
+ return platform_driver_register(&omap_wdt_driver);
+}
+
+static void __exit omap_wdt_exit(void)
+{
+ platform_driver_unregister(&omap_wdt_driver);
+}
+
+module_init(omap_wdt_init);
+module_exit(omap_wdt_exit);
+
+MODULE_AUTHOR("George G. Davis");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
git://git.onelab.eu / linux-2.6.git / blobdiff