watchdog: Add MCF548x watchdog driver.

Add watchdog driver for MCF548x.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

4 files changed, 236 insertions, 3 deletions

diff --git a/arch/m68k/include/asm/m548xgpt.h b/arch/m68k/include/asm/m548xgpt.h
index c8ef158a1c4e..33b2eef90f0a 100644
--- a/arch/m68k/include/asm/m548xgpt.h
+++ b/arch/m68k/include/asm/m548xgpt.h
@@ -59,11 +59,13 @@
 #define MCF_GPT_GMS_GPIO_INPUT     (0x00000000)
 #define MCF_GPT_GMS_GPIO_OUTLO     (0x00000020)
 #define MCF_GPT_GMS_GPIO_OUTHI     (0x00000030)
+#define MCF_GPT_GMS_GPIO_MASK      (0x00000030)
 #define MCF_GPT_GMS_TMS_DISABLE    (0x00000000)
 #define MCF_GPT_GMS_TMS_INCAPT     (0x00000001)
 #define MCF_GPT_GMS_TMS_OUTCAPT    (0x00000002)
 #define MCF_GPT_GMS_TMS_PWM        (0x00000003)
 #define MCF_GPT_GMS_TMS_GPIO       (0x00000004)
+#define MCF_GPT_GMS_TMS_MASK       (0x00000007)
 
 /* Bit definitions and macros for MCF_GPT_GCIR */
 #define MCF_GPT_GCIR_CNT(x)        (((x)&0x0000FFFF)<<0)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 68a9527f92d0..2e2400e7322e 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -862,7 +862,12 @@ config SBC_EPX_C3_WATCHDOG
 
 # M68K Architecture
 
-# M68KNOMMU Architecture
+config M548x_WATCHDOG
+        tristate "MCF548x watchdog support"
+        depends on M548x
+        help
+          To compile this driver as a module, choose M here: the
+          module will be called m548x_wdt.
 
 # MIPS Architecture
 
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 9b6b33a02072..dd776651917c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -106,8 +106,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 # M32R Architecture
 
 # M68K Architecture
-
-# M68KNOMMU Architecture
+obj-$(CONFIG_M548x_WATCHDOG) += m548x_wdt.o
 
 # MIPS Architecture
 obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
diff --git a/drivers/watchdog/m548x_wdt.c b/drivers/watchdog/m548x_wdt.c
new file mode 100644
index 000000000000..cabbcfe1c847
--- /dev/null
+++ b/drivers/watchdog/m548x_wdt.c
@@ -0,0 +1,227 @@
+/*
+ * drivers/watchdog/m548x_wdt.c
+ *
+ * Watchdog driver for ColdFire MCF548x processors
+ * Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be>
+ *
+ * Adapted from the IXP4xx watchdog driver, which carries these notices:
+ *
+ *  Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ *  Copyright 2004 (c) MontaVista, Software, Inc.
+ *  Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/ioport.h>
+#include <linux/uaccess.h>
+
+#include <asm/coldfire.h>
+#include <asm/m548xsim.h>
+#include <asm/m548xgpt.h>
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int heartbeat = 30;     /* (secs) Default is 0.5 minute */
+static unsigned long wdt_status;
+
+#define WDT_IN_USE              0
+#define WDT_OK_TO_CLOSE         1
+
+static void wdt_enable(void)
+{
+        unsigned int gms0;
+
+        /* preserve GPIO usage, if any */
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        if (gms0 & MCF_GPT_GMS_TMS_GPIO)
+                gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK
+                                                        | MCF_GPT_GMS_OD);
+        else
+                gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD;
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+        __raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) |
+                        MCF_GPT_GCIR_CNT(0xffff), MCF_MBAR + MCF_GPT_GCIR0);
+        gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE;
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static void wdt_disable(void)
+{
+        unsigned int gms0;
+
+        /* disable watchdog */
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE);
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static void wdt_keepalive(void)
+{
+        unsigned int gms0;
+
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        gms0 |= MCF_GPT_GMS_OCPW(0xA5);
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static int m548x_wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(WDT_IN_USE, &wdt_status))
+                return -EBUSY;
+
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+        wdt_enable();
+        return nonseekable_open(inode, file);
+}
+
+static ssize_t m548x_wdt_write(struct file *file, const char *data,
+                                                size_t len, loff_t *ppos)
+{
+        if (len) {
+                if (!nowayout) {
+                        size_t i;
+
+                        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+                        for (i = 0; i != len; i++) {
+                                char c;
+
+                                if (get_user(c, data + i))
+                                        return -EFAULT;
+                                if (c == 'V')
+                                        set_bit(WDT_OK_TO_CLOSE, &wdt_status);
+                        }
+                }
+                wdt_keepalive();
+        }
+        return len;
+}
+
+static const struct watchdog_info ident = {
+        .options        = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
+                                WDIOF_KEEPALIVEPING,
+        .identity       = "Coldfire M548x Watchdog",
+};
+
+static long m548x_wdt_ioctl(struct file *file, unsigned int cmd,
+                                                         unsigned long arg)
+{
+        int ret = -ENOTTY;
+        int time;
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+                ret = copy_to_user((struct watchdog_info *)arg, &ident,
+                                   sizeof(ident)) ? -EFAULT : 0;
+                break;
+
+        case WDIOC_GETSTATUS:
+                ret = put_user(0, (int *)arg);
+                break;
+
+        case WDIOC_GETBOOTSTATUS:
+                ret = put_user(0, (int *)arg);
+                break;
+
+        case WDIOC_KEEPALIVE:
+                wdt_keepalive();
+                ret = 0;
+                break;
+
+        case WDIOC_SETTIMEOUT:
+                ret = get_user(time, (int *)arg);
+                if (ret)
+                        break;
+
+                if (time <= 0 || time > 30) {
+                        ret = -EINVAL;
+                        break;
+                }
+
+                heartbeat = time;
+                wdt_enable();
+                /* Fall through */
+
+        case WDIOC_GETTIMEOUT:
+                ret = put_user(heartbeat, (int *)arg);
+                break;
+        }
+        return ret;
+}
+
+static int m548x_wdt_release(struct inode *inode, struct file *file)
+{
+        if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+                wdt_disable();
+        else {
+                printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
+                                        "timer will not stop\n");
+                wdt_keepalive();
+        }
+        clear_bit(WDT_IN_USE, &wdt_status);
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+        return 0;
+}
+
+
+static const struct file_operations m548x_wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = m548x_wdt_write,
+        .unlocked_ioctl = m548x_wdt_ioctl,
+        .open           = m548x_wdt_open,
+        .release        = m548x_wdt_release,
+};
+
+static struct miscdevice m548x_wdt_miscdev = {
+        .minor          = WATCHDOG_MINOR,
+        .name           = "watchdog",
+        .fops           = &m548x_wdt_fops,
+};
+
+static int __init m548x_wdt_init(void)
+{
+        if (!request_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4,
+                                                "Coldfire M548x Watchdog")) {
+                printk(KERN_WARNING
+                                "Coldfire M548x Watchdog : I/O region busy\n");
+                return -EBUSY;
+        }
+        printk(KERN_INFO "ColdFire watchdog driver is loaded.\n");
+
+        return misc_register(&m548x_wdt_miscdev);
+}
+
+static void __exit m548x_wdt_exit(void)
+{
+        misc_deregister(&m548x_wdt_miscdev);
+        release_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4);
+}
+
+module_init(m548x_wdt_init);
+module_exit(m548x_wdt_exit);
+
+MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
+MODULE_DESCRIPTION("Coldfire M548x Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);