[WATCHDOG] pnx4008: add watchdog support

Add watchdog support for Philips PNX4008 ARM board inlined.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 353 insertions, 0 deletions

diff --git a/drivers/char/watchdog/pnx4008_wdt.c b/drivers/char/watchdog/pnx4008_wdt.c
new file mode 100644
index 000000000000..7ae2d0888218
--- /dev/null
+++ b/drivers/char/watchdog/pnx4008_wdt.c
@@ -0,0 +1,353 @@
+/*
+ * drivers/char/watchdog/pnx4008_wdt.c
+ *
+ * Watchdog driver for PNX4008 board
+ *
+ * Authors: Dmitry Chigirev <source@mvista.com>,
+ *          Vitaly Wool <vitalywool@gmail.com>
+ * Based on sa1100 driver,
+ * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * 2005-2006 (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.
+ */
+
+#include <linux/config.h>
+#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/device.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <asm/hardware.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#define MODULE_NAME "PNX4008-WDT: "
+
+/* WatchDog Timer - Chapter 23 Page 207 */
+
+#define DEFAULT_HEARTBEAT 19
+#define MAX_HEARTBEAT     60
+
+/* Watchdog timer register set definition */
+#define WDTIM_INT(p)     ((p) + 0x0)
+#define WDTIM_CTRL(p)    ((p) + 0x4)
+#define WDTIM_COUNTER(p) ((p) + 0x8)
+#define WDTIM_MCTRL(p)   ((p) + 0xC)
+#define WDTIM_MATCH0(p)  ((p) + 0x10)
+#define WDTIM_EMR(p)     ((p) + 0x14)
+#define WDTIM_PULSE(p)   ((p) + 0x18)
+#define WDTIM_RES(p)     ((p) + 0x1C)
+
+/* WDTIM_INT bit definitions */
+#define MATCH_INT      1
+
+/* WDTIM_CTRL bit definitions */
+#define COUNT_ENAB     1
+#define RESET_COUNT    (1<<1)
+#define DEBUG_EN       (1<<2)
+
+/* WDTIM_MCTRL bit definitions */
+#define MR0_INT        1
+#undef  RESET_COUNT0
+#define RESET_COUNT0   (1<<2)
+#define STOP_COUNT0    (1<<2)
+#define M_RES1         (1<<3)
+#define M_RES2         (1<<4)
+#define RESFRC1        (1<<5)
+#define RESFRC2        (1<<6)
+
+/* WDTIM_EMR bit definitions */
+#define EXT_MATCH0      1
+#define MATCH_OUTPUT_HIGH (2<<4)        /*a MATCH_CTRL setting */
+
+/* WDTIM_RES bit definitions */
+#define WDOG_RESET      1       /* read only */
+
+#define WDOG_COUNTER_RATE 13000000      /*the counter clock is 13 MHz fixed */
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+static int heartbeat = DEFAULT_HEARTBEAT;
+
+static unsigned long wdt_status;
+#define WDT_IN_USE        0
+#define WDT_OK_TO_CLOSE   1
+#define WDT_REGION_INITED 2
+#define WDT_DEVICE_INITED 3
+
+static unsigned long boot_status;
+
+static struct resource  *wdt_mem;
+static void __iomem     *wdt_base;
+struct clk              *wdt_clk;
+
+static void wdt_enable(void)
+{
+        if (wdt_clk)
+                clk_set_rate(wdt_clk, 1);
+
+        /* stop counter, initiate counter reset */
+        __raw_writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
+        /*wait for reset to complete. 100% guarantee event */
+        while (__raw_readl(WDTIM_COUNTER(wdt_base)));
+        /* internal and external reset, stop after that */
+        __raw_writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0,
+                WDTIM_MCTRL(wdt_base));
+        /* configure match output */
+        __raw_writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
+        /* clear interrupt, just in case */
+        __raw_writel(MATCH_INT, WDTIM_INT(wdt_base));
+        /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
+        __raw_writel(0xFFFF, WDTIM_PULSE(wdt_base));
+        __raw_writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
+        /*enable counter, stop when debugger active */
+        __raw_writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
+}
+
+static void wdt_disable(void)
+{
+        __raw_writel(0, WDTIM_CTRL(wdt_base));  /*stop counter */
+        if (wdt_clk)
+                clk_set_rate(wdt_clk, 0);
+}
+
+static int pnx4008_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
+pnx4008_wdt_write(struct file *file, const char *data, size_t len,
+                  loff_t * ppos)
+{
+        /*  Can't seek (pwrite) on this device  */
+        if (ppos != &file->f_pos)
+                return -ESPIPE;
+
+        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_enable();
+        }
+
+        return len;
+}
+
+static struct watchdog_info ident = {
+        .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+            WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+        .identity = "PNX4008 Watchdog",
+};
+
+static int
+pnx4008_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+                  unsigned long arg)
+{
+        int ret = -ENOIOCTLCMD;
+        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(boot_status, (int *)arg);
+                break;
+
+        case WDIOC_SETTIMEOUT:
+                ret = get_user(time, (int *)arg);
+                if (ret)
+                        break;
+
+                if (time <= 0 || time > MAX_HEARTBEAT) {
+                        ret = -EINVAL;
+                        break;
+                }
+
+                heartbeat = time;
+                wdt_enable();
+                /* Fall through */
+
+        case WDIOC_GETTIMEOUT:
+                ret = put_user(heartbeat, (int *)arg);
+                break;
+
+        case WDIOC_KEEPALIVE:
+                wdt_enable();
+                ret = 0;
+                break;
+        }
+        return ret;
+}
+
+static int pnx4008_wdt_release(struct inode *inode, struct file *file)
+{
+        if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+                printk(KERN_WARNING "WATCHDOG: Device closed unexpectdly\n");
+
+        wdt_disable();
+        clear_bit(WDT_IN_USE, &wdt_status);
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+        return 0;
+}
+
+static struct file_operations pnx4008_wdt_fops = {
+        .owner = THIS_MODULE,
+        .llseek = no_llseek,
+        .write = pnx4008_wdt_write,
+        .ioctl = pnx4008_wdt_ioctl,
+        .open = pnx4008_wdt_open,
+        .release = pnx4008_wdt_release,
+};
+
+static struct miscdevice pnx4008_wdt_miscdev = {
+        .minor = WATCHDOG_MINOR,
+        .name = "watchdog",
+        .fops = &pnx4008_wdt_fops,
+};
+
+static int pnx4008_wdt_probe(struct platform_device *pdev)
+{
+        int ret = 0, size;
+        struct resource *res;
+
+        if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
+                heartbeat = DEFAULT_HEARTBEAT;
+
+        printk(KERN_INFO MODULE_NAME
+                "PNX4008 Watchdog Timer: heartbeat %d sec\n", heartbeat);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (res == NULL) {
+                printk(KERN_INFO MODULE_NAME
+                        "failed to get memory region resouce\n");
+                return -ENOENT;
+        }
+
+        size = res->end - res->start + 1;
+        wdt_mem = request_mem_region(res->start, size, pdev->name);
+
+        if (wdt_mem == NULL) {
+                printk(KERN_INFO MODULE_NAME "failed to get memory region\n");
+                return -ENOENT;
+        }
+        wdt_base = (void __iomem *)IO_ADDRESS(res->start);
+
+        wdt_clk = clk_get(&pdev->dev, "wdt_ck");
+        if (!wdt_clk) {
+                release_resource(wdt_mem);
+                kfree(wdt_mem);
+                goto out;
+        } else
+                clk_set_rate(wdt_clk, 1);
+
+        ret = misc_register(&pnx4008_wdt_miscdev);
+        if (ret < 0) {
+                printk(KERN_ERR MODULE_NAME "cannot register misc device\n");
+                release_resource(wdt_mem);
+                kfree(wdt_mem);
+                clk_set_rate(wdt_clk, 0);
+        } else {
+                boot_status = (__raw_readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
+                    WDIOF_CARDRESET : 0;
+                wdt_disable();          /*disable for now */
+                set_bit(WDT_DEVICE_INITED, &wdt_status);
+        }
+
+out:
+        return ret;
+}
+
+static int pnx4008_wdt_remove(struct platform_device *pdev)
+{
+        if (wdt_mem) {
+                release_resource(wdt_mem);
+                kfree(wdt_mem);
+                wdt_mem = NULL;
+        }
+        if (wdt_clk) {
+                clk_set_rate(wdt_clk, 0);
+                clk_put(wdt_clk);
+                wdt_clk = NULL;
+        }
+        misc_deregister(&pnx4008_wdt_miscdev);
+        return 0;
+}
+
+static struct platform_driver platform_wdt_driver = {
+        .driver = {
+                .name = "watchdog",
+        },
+        .probe = pnx4008_wdt_probe,
+        .remove = pnx4008_wdt_remove,
+};
+
+static int __init pnx4008_wdt_init(void)
+{
+        return platform_driver_register(&platform_wdt_driver);
+}
+
+static void __exit pnx4008_wdt_exit(void)
+{
+        return platform_driver_unregister(&platform_wdt_driver);
+}
+
+module_init(pnx4008_wdt_init);
+module_exit(pnx4008_wdt_exit);
+
+MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
+MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+                 "Watchdog heartbeat period in seconds from 1 to "
+                 __MODULE_STRING(MAX_HEARTBEAT) ", default "
+                 __MODULE_STRING(DEFAULT_HEARTBEAT));
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+                 "Set to 1 to keep watchdog running after device release");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);