linux-mips
[Top] [All Lists]

[PATCH] MIPS RM9K watchdog driver

To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: [PATCH] MIPS RM9K watchdog driver
From: thomas@koeller.dyndns.org
Date: Sat, 12 Aug 2006 18:05:52 +0200
Cc: wim@iguana.be, linux-kernel@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
Organization: Basler AG
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
This is a driver for the on-chip watchdog device found on some
MIPS RM9000 processors.

Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
---
 drivers/char/watchdog/Kconfig    |   10 +
 drivers/char/watchdog/Makefile   |    1 
 drivers/char/watchdog/rm9k_wdt.c |  440 
++++++++++++++++++++++++++++++++++++++
 3 files changed, 451 insertions(+), 0 deletions(-)

diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig
index d53f664..3207299 100644
--- a/drivers/char/watchdog/Kconfig
+++ b/drivers/char/watchdog/Kconfig
@@ -477,6 +477,16 @@ config INDYDOG
          timer expired and no process has written to /dev/watchdog during
          that time.
 
+config WDT_RM9K_GPI
+       tristate "RM9000/GPI hardware watchdog"
+       depends on WATCHDOG && CPU_RM9000
+       help
+         Watchdog implementation using the GPI hardware found on
+         PMC-Sierra RM9xxx CPUs.
+         
+         To compile this driver as a module, choose M here: the
+         module will be called rm9k_wdt.
+
 # S390 Architecture
 
 config ZVM_WATCHDOG
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile
index 6ab77b6..f2a6281 100644
--- a/drivers/char/watchdog/Makefile
+++ b/drivers/char/watchdog/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
 
 # MIPS Architecture
 obj-$(CONFIG_INDYDOG) += indydog.o
+obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o
 
 # S390 Architecture
 
diff --git a/drivers/char/watchdog/rm9k_wdt.c 
b/drivers/char/watchdog/rm9k_wdt.c
new file mode 100644
index 0000000..8ed1c12
--- /dev/null
+++ b/drivers/char/watchdog/rm9k_wdt.c
@@ -0,0 +1,440 @@
+/*
+ *  Watchdog implementation for GPI h/w found on PMC-Sierra RM9xxx
+ *  chips.
+ *
+ *  Copyright (C) 2004 by Basler Vision Technologies AG
+ *  Author: Thomas Koeller <thomas.koeller@baslerweb.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+ 
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/rm9k-ocd.h>
+
+#include <rm9k_wdt.h>
+
+
+#define CLOCK                  125000000
+#define MAX_TIMEOUT_SECONDS    32
+#define CPCCR                  0x0080
+#define CPGIG1SR               0x0044
+#define CPGIG1ER               0x0054
+
+
+
+/* Function prototypes */
+static int __init wdt_gpi_probe(struct device *);
+static int __exit wdt_gpi_remove(struct device *);
+static void wdt_gpi_set_timeout(unsigned int);
+static int wdt_gpi_open(struct inode *, struct file *);
+static int wdt_gpi_release(struct inode *, struct file *);
+static ssize_t wdt_gpi_write(struct file *, const char __user *, size_t, 
loff_t *);
+static long wdt_gpi_ioctl(struct file *, unsigned int, unsigned long);
+static const struct resource *wdt_gpi_get_resource(struct platform_device *, 
const char *, unsigned int);
+static int wdt_gpi_notify(struct notifier_block *, unsigned long, void *);
+static irqreturn_t wdt_gpi_irqhdl(int, void *, struct pt_regs *);
+
+
+
+
+static const char wdt_gpi_name[] = "wdt_gpi";
+static atomic_t opencnt;
+static int expect_close;
+static int locked = 0;
+
+
+
+/* These are set from device resources */
+static void __iomem * wd_regs;
+static unsigned int wd_irq, wd_ctr;
+
+
+
+/* Module arguments */
+static int timeout = MAX_TIMEOUT_SECONDS;
+module_param(timeout, int, 444);
+static unsigned long resetaddr = 0xbffdc200;
+module_param(resetaddr, ulong, 444);
+static unsigned long flagaddr = 0xbffdc104;
+module_param(flagaddr, ulong, 444);
+static int powercycle = 0;
+module_param(powercycle, bool, 444);
+
+static int nowayout =
+#if defined(CONFIG_WATCHDOG_NOWAYOUT)
+       1;
+#else
+       0;
+#endif
+module_param(nowayout, bool, 444);
+
+
+
+static struct file_operations fops =
+{
+       .owner          = THIS_MODULE,
+       .open           = wdt_gpi_open,
+       .release        = wdt_gpi_release,
+       .write          = wdt_gpi_write,
+       .unlocked_ioctl = wdt_gpi_ioctl
+};
+
+static struct miscdevice miscdev =
+{
+       .minor          = WATCHDOG_MINOR,
+       .name           = wdt_gpi_name,
+       .fops           = &fops
+};
+
+static struct device_driver wdt_gpi_driver =
+{
+       .name           = (char *) wdt_gpi_name,
+       .bus            = &platform_bus_type,
+       .owner          = THIS_MODULE,
+       .probe          = wdt_gpi_probe,
+       .remove         = __exit_p(wdt_gpi_remove),
+       .shutdown       = NULL,
+       .suspend        = NULL,
+       .resume         = NULL
+};
+
+static struct notifier_block wdt_gpi_shutdown =
+{
+       wdt_gpi_notify
+};
+
+
+
+static const struct resource *
+wdt_gpi_get_resource(struct platform_device *pdv, const char *name,
+                    unsigned int type)
+{
+       char buf[80];
+       if (snprintf(buf, sizeof buf, "%s_0", name) >= sizeof buf)
+               return NULL;
+       return platform_get_resource_byname(pdv, type, buf);
+}
+
+
+
+/* No hotplugging on the platform bus - use __init */
+static int __init wdt_gpi_probe(struct device *dev)
+{
+       int res;
+       struct platform_device * const pdv = to_platform_device(dev);
+       const struct resource
+               * const rr = wdt_gpi_get_resource(pdv, WDT_RESOURCE_REGS,
+                                                 IORESOURCE_MEM),
+               * const ri = wdt_gpi_get_resource(pdv, WDT_RESOURCE_IRQ,
+                                                 IORESOURCE_IRQ),
+               * const rc = wdt_gpi_get_resource(pdv, WDT_RESOURCE_COUNTER,
+                                                 0);
+
+       if (unlikely(!rr || !ri || !rc))
+               return -ENXIO;
+
+       wd_regs = ioremap_nocache(rr->start, rr->end + 1 - rr->start);
+       if (unlikely(!wd_regs))
+               return -ENOMEM;
+       wd_irq = ri->start;
+       wd_ctr = rc->start;
+       res = misc_register(&miscdev);
+       if (res)
+               iounmap(wd_regs);
+       else
+               register_reboot_notifier(&wdt_gpi_shutdown);
+       return res;
+}
+
+
+
+static int __exit wdt_gpi_remove(struct device *dev)
+{
+       int res;
+
+       unregister_reboot_notifier(&wdt_gpi_shutdown);
+       res = misc_deregister(&miscdev);
+       iounmap(wd_regs);
+       wd_regs = NULL;
+       return res;
+}
+
+
+static void wdt_gpi_set_timeout(unsigned int to)
+{
+       u32 reg;
+       const u32 wdval = (to * CLOCK) & ~0x0000000f;
+
+       lock_titan_regs();
+       reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));
+       titan_writel(reg, CPCCR);
+       wmb();
+       __raw_writel(wdval, wd_regs + 0x0000);
+       wmb();
+       titan_writel(reg | (0x2 << (wd_ctr * 4)), CPCCR);
+       wmb();
+       titan_writel(reg | (0x5 << (wd_ctr * 4)), CPCCR);
+       iob();
+       unlock_titan_regs();
+}
+
+
+
+static int wdt_gpi_open(struct inode *i, struct file *f)
+{
+       int res;
+       u32 reg;
+
+       if (unlikely(0 > atomic_dec_if_positive(&opencnt)))
+               return -EBUSY;
+
+       expect_close = 0;
+       if (locked) {
+               module_put(THIS_MODULE);
+               free_irq(wd_irq, &miscdev);
+               locked = 0;
+       }
+
+       res = request_irq(wd_irq, wdt_gpi_irqhdl, SA_SHIRQ | SA_INTERRUPT,
+                         wdt_gpi_name, &miscdev);
+       if (unlikely(res))
+               return res;
+
+       wdt_gpi_set_timeout(timeout);
+
+       lock_titan_regs();
+       reg = titan_readl(CPGIG1ER);
+       titan_writel(reg | (0x100 << wd_ctr), CPGIG1ER);
+       iob();
+       unlock_titan_regs();
+
+       printk(KERN_INFO "%s: watchdog started, timeout = %u seconds\n",
+              wdt_gpi_name, timeout);
+       return 0;
+}
+
+
+
+static int wdt_gpi_release(struct inode *i, struct file *f)
+{
+       if (nowayout) {
+               printk(KERN_NOTICE "%s: no way out - watchdog left running\n",
+                      wdt_gpi_name);
+               __module_get(THIS_MODULE);
+               locked = 1;
+       } else {
+               if (expect_close) {
+                       u32 reg;
+
+                       lock_titan_regs();
+                       reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));
+                       titan_writel(reg, CPCCR);
+                       reg = titan_readl(CPGIG1ER);
+                       titan_writel(reg & ~(0x100 << wd_ctr), CPGIG1ER);
+                       iob();
+                       unlock_titan_regs();
+                       free_irq(wd_irq, &miscdev);
+                       printk(KERN_INFO "%s: watchdog stopped\n", 
wdt_gpi_name);
+               } else {
+                       printk(KERN_NOTICE "%s: unexpected close() -"
+                              " watchdog left running\n",
+                              wdt_gpi_name);
+                       wdt_gpi_set_timeout(timeout);
+                       __module_get(THIS_MODULE);
+                       locked = 1;
+               }
+       }
+
+       atomic_inc(&opencnt);
+       return 0;
+}
+
+
+
+static ssize_t
+wdt_gpi_write(struct file *f, const char __user *d, size_t s, loff_t *o)
+{
+       char val;
+
+       wdt_gpi_set_timeout(timeout);
+       expect_close = (s > 0) && !get_user(val, d) && (val == 'V');
+       return s ? 1 : 0;
+}
+
+
+
+static long
+wdt_gpi_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+       long res = -ENOTTY;
+       const long size = _IOC_SIZE(cmd);
+       int stat;
+       static struct watchdog_info wdinfo = {
+               .identity               = "RM9xxx/GPI watchdog",
+               .firmware_version       = 0,
+               .options                = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING
+       };
+
+       if (unlikely(_IOC_TYPE(cmd) != WATCHDOG_IOCTL_BASE))
+               return -ENOTTY;
+
+       if ((_IOC_DIR(cmd) & _IOC_READ)
+           && !access_ok(VERIFY_WRITE, arg, size))
+               return -EFAULT;
+
+       if ((_IOC_DIR(cmd) & _IOC_WRITE)
+           && !access_ok(VERIFY_READ, arg, size))
+               return -EFAULT;
+
+       expect_close = 0;
+
+       switch (cmd) {
+               case WDIOC_GETSUPPORT:
+                       wdinfo.options = nowayout ?
+                               WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING :
+                               WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | 
WDIOF_MAGICCLOSE;
+                       res = __copy_to_user((void __user *)arg, &wdinfo, size) 
?
+                               -EFAULT : size;
+                       break;
+
+               case WDIOC_GETSTATUS:
+                       break;
+               
+               case WDIOC_GETBOOTSTATUS:
+                       stat = (*(volatile char *) flagaddr & 0x01)
+                               ? WDIOF_CARDRESET : 0;
+                       res = __copy_to_user((void __user *)arg, &stat, size) ?
+                               -EFAULT : size;
+                       break;
+
+               case WDIOC_SETOPTIONS:
+                       break;
+
+               case WDIOC_KEEPALIVE:
+                       wdt_gpi_set_timeout(timeout);
+                       res = size;
+                       break;
+
+               case WDIOC_SETTIMEOUT:
+                       {
+                               int val;
+                               if (unlikely(__copy_from_user(&val, (const void 
__user *) arg,
+                                                    size))) {
+                                       res = -EFAULT;
+                                       break;
+                               }
+
+                               if (val > 32)
+                                       val = 32;
+                               timeout = val;
+                               wdt_gpi_set_timeout(val);
+                               res = size;
+                               printk("%s: timeout set to %u seconds\n",
+                                      wdt_gpi_name, timeout);
+                       }
+                       break;
+
+               case WDIOC_GETTIMEOUT:
+                       res = __copy_to_user((void __user *) arg, &timeout, 
size) ?
+                               -EFAULT : size;
+                       break;
+       }
+       
+       return res;
+}
+
+
+
+
+static irqreturn_t wdt_gpi_irqhdl(int irq, void *ctxt, struct pt_regs *regs)
+{
+       if (!unlikely(__raw_readl(wd_regs + 0x0008) & 0x1))
+               return IRQ_NONE;
+       __raw_writel(0x1, wd_regs + 0x0008);
+
+
+       printk(KERN_WARNING "%s: watchdog expired - resetting system\n",
+              wdt_gpi_name);
+
+       *(volatile char *) flagaddr |= 0x01;
+       *(volatile char *) resetaddr = powercycle ? 0x01 : 0x2;
+       iob();
+       while (1)
+               cpu_relax();
+}
+
+
+
+static int
+wdt_gpi_notify(struct notifier_block *this, unsigned long code, void *unused)
+{
+       if(code == SYS_DOWN || code == SYS_HALT) {
+               u32 reg;
+
+               lock_titan_regs();
+               reg = titan_readl(CPCCR) & ~(0xf << (wd_ctr * 4));
+               titan_writel(reg, CPCCR);
+               reg = titan_readl(CPGIG1ER);
+               titan_writel(reg & ~(0x100 << wd_ctr), CPGIG1ER);
+               iob();
+               unlock_titan_regs();
+       }
+       return NOTIFY_DONE;
+}
+
+
+
+static int __init wdt_gpi_init_module(void)
+{
+       atomic_set(&opencnt, 1);
+       if (timeout > MAX_TIMEOUT_SECONDS)
+               timeout = MAX_TIMEOUT_SECONDS;
+       return driver_register(&wdt_gpi_driver);
+}
+
+
+
+static void __exit wdt_gpi_cleanup_module(void)
+{
+       driver_unregister(&wdt_gpi_driver);
+}
+
+module_init(wdt_gpi_init_module);
+module_exit(wdt_gpi_cleanup_module);
+
+
+
+MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
+MODULE_DESCRIPTION("Basler eXcite watchdog driver for gpi devices");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
+MODULE_PARM_DESC(resetaddr, "Address to write to to force a reset");
+MODULE_PARM_DESC(flagaddr, "Address to write to boot flags to");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be disabled once started");
+MODULE_PARM_DESC(powercycle, "Cycle power if watchdog expires");
-- 
1.4.0


-- 
Thomas Koeller, Software Development

Basler Vision Technologies
An der Strusbek 60-62
22926 Ahrensburg
Germany

Tel +49 (4102) 463-390
Fax +49 (4102) 463-46390

mailto:thomas.koeller@baslerweb.com
http://www.baslerweb.com

<Prev in Thread] Current Thread [Next in Thread>