[PATCH] powerpc: Watchdog timer support for GE Fanuc SBC610
Martyn Welch
martyn.welch at gefanuc.com
Sat Nov 8 01:38:22 EST 2008
Support for the SBC610 VPX Single Baord Computer from GE Fanuc (PowerPC
MPC8641D).
This patch adds support for the watchdog timer in the devices main FPGA.
There are two identical watchdog timers at different offsets in the main
FPGA, this driver is capable of supporting one of them. The watchdog timers
are also capable of generating interrupts at a user-configurable threshold,
though support for this operation is currently not supported by the driver.
Signed-off-by: Martyn Welch <martyn.welch at gefanuc.com>
---
arch/powerpc/boot/dts/gef_sbc610.dts | 19 +
arch/powerpc/configs/86xx/gef_sbc610_defconfig | 1
drivers/watchdog/Kconfig | 6
drivers/watchdog/Makefile | 1
drivers/watchdog/gef_wdt.c | 333 ++++++++++++++++++++++++
5 files changed, 360 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/boot/dts/gef_sbc610.dts b/arch/powerpc/boot/dts/gef_sbc610.dts
index 1f7833c..5c7a38a 100644
--- a/arch/powerpc/boot/dts/gef_sbc610.dts
+++ b/arch/powerpc/boot/dts/gef_sbc610.dts
@@ -88,6 +88,25 @@
compatible = "gef,fpga-regs";
reg = <0x4 0x0 0x40>;
};
+
+ wdt at 4,2000 {
+ #interrupt-cells = <2>;
+ device_type = "watchdog";
+ compatible = "gef,fpga-wdt";
+ reg = <0x4 0x2000 0x8>;
+ interrupts = <0x1a 0x4>;
+ interrupt-parent = <&gef_pic>;
+ };
+ /* Second watchdog available, driver currently supports one.
+ wdt at 4,2010 {
+ #interrupt-cells = <2>;
+ device_type = "watchdog";
+ compatible = "gef,fpga-wdt";
+ reg = <0x4 0x2010 0x8>;
+ interrupts = <0x1b 0x4>;
+ interrupt-parent = <&gef_pic>;
+ };
+ */
gef_pic: pic at 4,4000 {
#interrupt-cells = <1>;
interrupt-controller;
diff --git a/arch/powerpc/configs/86xx/gef_sbc610_defconfig b/arch/powerpc/configs/86xx/gef_sbc610_defconfig
index 312d7af..99fe882 100644
--- a/arch/powerpc/configs/86xx/gef_sbc610_defconfig
+++ b/arch/powerpc/configs/86xx/gef_sbc610_defconfig
@@ -1109,6 +1109,7 @@ CONFIG_WATCHDOG=y
# Watchdog Device Drivers
#
# CONFIG_SOFT_WATCHDOG is not set
+CONFIG_GEF_WDT=y
#
# PCI-based Watchdog Cards
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1a22fe7..df91e88 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -778,6 +778,12 @@ config BOOKE_WDT
Please see Documentation/watchdog/watchdog-api.txt for
more information.
+config GEF_WDT
+ tristate "GE Fanuc Watchdog Timer"
+ depends on GEF_SBC610
+ ---help---
+ Watchdog timer found in a number of GE Fanuc single board computers.
+
# PPC64 Architecture
config WATCHDOG_RTAS
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index e352bbb..be7e1d3 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -114,6 +114,7 @@ obj-$(CONFIG_MPC5200_WDT) += mpc5200_wdt.o
obj-$(CONFIG_8xxx_WDT) += mpc8xxx_wdt.o
obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o
obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o
+obj-$(CONFIG_GEF_WDT) += gef_wdt.o
# PPC64 Architecture
obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
diff --git a/drivers/watchdog/gef_wdt.c b/drivers/watchdog/gef_wdt.c
new file mode 100644
index 0000000..f82ef9c
--- /dev/null
+++ b/drivers/watchdog/gef_wdt.c
@@ -0,0 +1,333 @@
+/*
+ * GE Fanuc watchdog userspace interface
+ *
+ * Author: Martyn Welch <martyn.welch at gefanuc.com>
+ *
+ * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * 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.
+ *
+ * Based on: mv64x60_wdt.c (MV64X60 watchdog userspace interface)
+ * Author: James Chapman <jchapman at katalix.com>
+ */
+
+/* TODO:
+ * This driver does not provide support for the hardwares capability of sending
+ * an interrupt at a programmable threshold.
+ *
+ * This driver currently can only support 1 watchdog - there are 2 in the
+ * hardware that this driver supports. Thus one could be configured as a
+ * process-based watchdog (via /dev/watchdog), the second (using the interrupt
+ * capabilities) a kernel-based watchdog.
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <sysdev/fsl_soc.h>
+
+/*
+ * The watchdog configuration register contains a pair of 2-bit fields,
+ * 1. a reload field, bits 27-26, which triggers a reload of
+ * the countdown register, and
+ * 2. an enable field, bits 25-24, which toggles between
+ * enabling and disabling the watchdog timer.
+ * Bit 31 is a read-only field which indicates whether the
+ * watchdog timer is currently enabled.
+ *
+ * The low 24 bits contain the timer reload value.
+ */
+#define GEF_WDC_ENABLE_SHIFT 24
+#define GEF_WDC_SERVICE_SHIFT 26
+#define GEF_WDC_ENABLED_SHIFT 31
+
+#define GEF_WDC_ENABLED_TRUE 1
+#define GEF_WDC_ENABLED_FALSE 0
+
+/* Flags bits */
+#define GEF_WDOG_FLAG_OPENED 0
+
+static unsigned long wdt_flags;
+static int wdt_status;
+static void __iomem *gef_wdt_regs;
+static int gef_wdt_timeout;
+static int gef_wdt_count;
+static unsigned int bus_clk;
+static char expect_close;
+static DEFINE_SPINLOCK(gef_wdt_spinlock);
+
+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) ")");
+
+
+static int gef_wdt_toggle_wdc(int enabled_predicate, int field_shift)
+{
+ u32 data;
+ u32 enabled;
+ int ret = 0;
+
+ spin_lock(&gef_wdt_spinlock);
+ data = ioread32be(gef_wdt_regs);
+ enabled = (data >> GEF_WDC_ENABLED_SHIFT) & 1;
+
+ /* only toggle the requested field if enabled state matches predicate */
+ if ((enabled ^ enabled_predicate) == 0) {
+ /* We write a 1, then a 2 -- to the appropriate field */
+ data = (1 << field_shift) | gef_wdt_count;
+ iowrite32be(data, gef_wdt_regs);
+
+ data = (2 << field_shift) | gef_wdt_count;
+ iowrite32be(data, gef_wdt_regs);
+ ret = 1;
+ }
+ spin_unlock(&gef_wdt_spinlock);
+
+ return ret;
+}
+
+static void gef_wdt_service(void)
+{
+ gef_wdt_toggle_wdc(GEF_WDC_ENABLED_TRUE,
+ GEF_WDC_SERVICE_SHIFT);
+}
+
+static void gef_wdt_handler_enable(void)
+{
+ if (gef_wdt_toggle_wdc(GEF_WDC_ENABLED_FALSE,
+ GEF_WDC_ENABLE_SHIFT)) {
+ gef_wdt_service();
+ printk(KERN_NOTICE "gef_wdt: watchdog activated\n");
+ }
+}
+
+static void gef_wdt_handler_disable(void)
+{
+ if (gef_wdt_toggle_wdc(GEF_WDC_ENABLED_TRUE,
+ GEF_WDC_ENABLE_SHIFT))
+ printk(KERN_NOTICE "gef_wdt: watchdog deactivated\n");
+}
+
+static void gef_wdt_set_timeout(unsigned int timeout)
+{
+ /* maximum bus cycle count is 0xFFFFFFFF */
+ if (timeout > 0xFFFFFFFF / bus_clk)
+ timeout = 0xFFFFFFFF / bus_clk;
+
+ /* Register only holds upper 24 bits, bit shifted into lower 24 */
+ gef_wdt_count = (timeout * bus_clk) >> 8;
+ gef_wdt_timeout = timeout;
+}
+
+
+static ssize_t gef_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ expect_close = 0;
+
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+ gef_wdt_service();
+ }
+
+ return len;
+}
+
+static int gef_wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int timeout;
+ int options;
+ void __user *argp = (void __user *)arg;
+ static struct watchdog_info info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .firmware_version = 0,
+ .identity = "GE Fanuc watchdog",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &info, sizeof(info)))
+ return -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ if (put_user(wdt_status, (int __user *)argp))
+ return -EFAULT;
+ wdt_status &= ~WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_GETTEMP:
+ return -EOPNOTSUPP;
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(options, (int __user *)argp))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD)
+ gef_wdt_handler_disable();
+
+ if (options & WDIOS_ENABLECARD)
+ gef_wdt_handler_enable();
+ break;
+
+ case WDIOC_KEEPALIVE:
+ gef_wdt_service();
+ wdt_status |= WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(timeout, (int __user *)argp))
+ return -EFAULT;
+ gef_wdt_set_timeout(timeout);
+ /* Fall through */
+
+ case WDIOC_GETTIMEOUT:
+ if (put_user(gef_wdt_timeout, (int __user *)argp))
+ return -EFAULT;
+ break;
+
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static int gef_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(GEF_WDOG_FLAG_OPENED, &wdt_flags))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ gef_wdt_handler_enable();
+
+ return nonseekable_open(inode, file);
+}
+
+static int gef_wdt_release(struct inode *inode, struct file *file)
+{
+ if (expect_close == 42)
+ gef_wdt_handler_disable();
+ else {
+ printk(KERN_CRIT
+ "gef_wdt: unexpected close, not stopping timer!\n");
+ gef_wdt_service();
+ }
+ expect_close = 0;
+
+ clear_bit(GEF_WDOG_FLAG_OPENED, &wdt_flags);
+
+ return 0;
+}
+
+static const struct file_operations gef_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = gef_wdt_write,
+ .ioctl = gef_wdt_ioctl,
+ .open = gef_wdt_open,
+ .release = gef_wdt_release,
+};
+
+static struct miscdevice gef_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &gef_wdt_fops,
+};
+
+
+static int __devinit gef_wdt_probe(struct of_device *dev,
+ const struct of_device_id *match)
+{
+ int timeout = 10;
+ u32 freq;
+
+ bus_clk = 133; /* in MHz */
+
+ freq = fsl_get_sys_freq();
+ if (freq > 0)
+ bus_clk = freq;
+
+ /* Map devices registers into memory */
+ gef_wdt_regs = of_iomap(dev->node, 0);
+ if (gef_wdt_regs == NULL)
+ return -ENOMEM;
+
+ gef_wdt_set_timeout(timeout);
+
+ gef_wdt_handler_disable(); /* in case timer was already running */
+
+ return misc_register(&gef_wdt_miscdev);
+}
+
+static int __devexit gef_wdt_remove(struct platform_device *dev)
+{
+ misc_deregister(&gef_wdt_miscdev);
+
+ gef_wdt_handler_disable();
+
+ iounmap(gef_wdt_regs);
+
+ return 0;
+}
+
+static const struct of_device_id gef_wdt_ids[] = {
+ {
+ .compatible = "gef,fpga-wdt",
+ },
+ {},
+};
+
+static struct of_platform_driver gef_wdt_driver = {
+ .owner = THIS_MODULE,
+ .name = "gef_wdt",
+ .match_table = gef_wdt_ids,
+ .probe = gef_wdt_probe,
+};
+
+static int __init gef_wdt_init(void)
+{
+ printk(KERN_INFO "GE Fanuc watchdog driver\n");
+ return of_register_platform_driver(&gef_wdt_driver);
+}
+
+static void __exit gef_wdt_exit(void)
+{
+ of_unregister_platform_driver(&gef_wdt_driver);
+}
+
+module_init(gef_wdt_init);
+module_exit(gef_wdt_exit);
+
+MODULE_AUTHOR("Martyn Welch <martyn.welch at gefanuc.com>");
+MODULE_DESCRIPTION("GE Fanuc watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform: gef_wdt");
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