+// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/char/watchdog/ixp4xx_wdt.c
*
* Watchdog driver for Intel IXP4xx network processors
*
* Author: Deepak Saxena <dsaxena@plexity.net>
+ * Author: Linus Walleij <linus.walleij@linaro.org>
*
* 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.
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
#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/of.h>
#include <linux/watchdog.h>
-#include <linux/init.h>
-#include <linux/bitops.h>
-#include <linux/uaccess.h>
-#include <mach/hardware.h>
+#include <linux/bits.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/soc/ixp4xx/cpu.h>
+
+struct ixp4xx_wdt {
+ struct watchdog_device wdd;
+ void __iomem *base;
+ unsigned long rate;
+};
-static bool nowayout = WATCHDOG_NOWAYOUT;
-static int heartbeat = 60; /* (secs) Default is 1 minute */
-static unsigned long wdt_status;
-static unsigned long boot_status;
-static DEFINE_SPINLOCK(wdt_lock);
+/* Fallback if we do not have a clock for this */
+#define IXP4XX_TIMER_FREQ 66666000
-#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL)
+/* Registers after the timer registers */
+#define IXP4XX_OSWT_OFFSET 0x14 /* Watchdog Timer */
+#define IXP4XX_OSWE_OFFSET 0x18 /* Watchdog Enable */
+#define IXP4XX_OSWK_OFFSET 0x1C /* Watchdog Key */
+#define IXP4XX_OSST_OFFSET 0x20 /* Timer Status */
-#define WDT_IN_USE 0
-#define WDT_OK_TO_CLOSE 1
+#define IXP4XX_OSST_TIMER_WDOG_PEND 0x00000008
+#define IXP4XX_OSST_TIMER_WARM_RESET 0x00000010
+#define IXP4XX_WDT_KEY 0x0000482E
+#define IXP4XX_WDT_RESET_ENABLE 0x00000001
+#define IXP4XX_WDT_IRQ_ENABLE 0x00000002
+#define IXP4XX_WDT_COUNT_ENABLE 0x00000004
-static void wdt_enable(void)
+static inline
+struct ixp4xx_wdt *to_ixp4xx_wdt(struct watchdog_device *wdd)
{
- spin_lock(&wdt_lock);
- *IXP4XX_OSWK = IXP4XX_WDT_KEY;
- *IXP4XX_OSWE = 0;
- *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat;
- *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE;
- *IXP4XX_OSWK = 0;
- spin_unlock(&wdt_lock);
+ return container_of(wdd, struct ixp4xx_wdt, wdd);
}
-static void wdt_disable(void)
+static int ixp4xx_wdt_start(struct watchdog_device *wdd)
{
- spin_lock(&wdt_lock);
- *IXP4XX_OSWK = IXP4XX_WDT_KEY;
- *IXP4XX_OSWE = 0;
- *IXP4XX_OSWK = 0;
- spin_unlock(&wdt_lock);
-}
+ struct ixp4xx_wdt *iwdt = to_ixp4xx_wdt(wdd);
-static int ixp4xx_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(WDT_IN_USE, &wdt_status))
- return -EBUSY;
+ __raw_writel(IXP4XX_WDT_KEY, iwdt->base + IXP4XX_OSWK_OFFSET);
+ __raw_writel(0, iwdt->base + IXP4XX_OSWE_OFFSET);
+ __raw_writel(wdd->timeout * iwdt->rate,
+ iwdt->base + IXP4XX_OSWT_OFFSET);
+ __raw_writel(IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE,
+ iwdt->base + IXP4XX_OSWE_OFFSET);
+ __raw_writel(0, iwdt->base + IXP4XX_OSWK_OFFSET);
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
- wdt_enable();
- return stream_open(inode, file);
+ return 0;
}
-static ssize_t
-ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+static int ixp4xx_wdt_stop(struct watchdog_device *wdd)
{
- 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;
-}
+ struct ixp4xx_wdt *iwdt = to_ixp4xx_wdt(wdd);
-static const struct watchdog_info ident = {
- .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
- WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
- .identity = "IXP4xx Watchdog",
-};
+ __raw_writel(IXP4XX_WDT_KEY, iwdt->base + IXP4XX_OSWK_OFFSET);
+ __raw_writel(0, iwdt->base + IXP4XX_OSWE_OFFSET);
+ __raw_writel(0, iwdt->base + IXP4XX_OSWK_OFFSET);
-
-static long ixp4xx_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(boot_status, (int *)arg);
- break;
-
- case WDIOC_KEEPALIVE:
- wdt_enable();
- ret = 0;
- break;
-
- case WDIOC_SETTIMEOUT:
- ret = get_user(time, (int *)arg);
- if (ret)
- break;
-
- if (time <= 0 || time > 60) {
- ret = -EINVAL;
- break;
- }
-
- heartbeat = time;
- wdt_enable();
- fallthrough;
-
- case WDIOC_GETTIMEOUT:
- ret = put_user(heartbeat, (int *)arg);
- break;
- }
- return ret;
+ return 0;
}
-static int ixp4xx_wdt_release(struct inode *inode, struct file *file)
+static int ixp4xx_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
{
- if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
- wdt_disable();
- else
- pr_crit("Device closed unexpectedly - timer will not stop\n");
- clear_bit(WDT_IN_USE, &wdt_status);
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+ wdd->timeout = timeout;
+ if (watchdog_active(wdd))
+ ixp4xx_wdt_start(wdd);
return 0;
}
-
-static const struct file_operations ixp4xx_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = ixp4xx_wdt_write,
- .unlocked_ioctl = ixp4xx_wdt_ioctl,
- .compat_ioctl = compat_ptr_ioctl,
- .open = ixp4xx_wdt_open,
- .release = ixp4xx_wdt_release,
+static const struct watchdog_ops ixp4xx_wdt_ops = {
+ .start = ixp4xx_wdt_start,
+ .stop = ixp4xx_wdt_stop,
+ .set_timeout = ixp4xx_wdt_set_timeout,
+ .owner = THIS_MODULE,
};
-static struct miscdevice ixp4xx_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &ixp4xx_wdt_fops,
+static const struct watchdog_info ixp4xx_wdt_info = {
+ .options = WDIOF_KEEPALIVEPING
+ | WDIOF_MAGICCLOSE
+ | WDIOF_SETTIMEOUT,
+ .identity = KBUILD_MODNAME,
};
-static int __init ixp4xx_wdt_init(void)
+/* Devres-handled clock disablement */
+static void ixp4xx_clock_action(void *d)
+{
+ clk_disable_unprepare(d);
+}
+
+static int ixp4xx_wdt_probe(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
+ struct ixp4xx_wdt *iwdt;
+ struct clk *clk;
int ret;
- /*
- * FIXME: we bail out on device tree boot but this really needs
- * to be fixed in a nicer way: this registers the MDIO bus before
- * even matching the driver infrastructure, we should only probe
- * detected hardware.
- */
- if (of_have_populated_dt())
- return -ENODEV;
if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) {
- pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n");
-
+ dev_err(dev, "Rev. A0 IXP42x CPU detected - watchdog disabled\n");
return -ENODEV;
}
- boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ?
- WDIOF_CARDRESET : 0;
- ret = misc_register(&ixp4xx_wdt_miscdev);
- if (ret == 0)
- pr_info("timer heartbeat %d sec\n", heartbeat);
- return ret;
-}
-static void __exit ixp4xx_wdt_exit(void)
-{
- misc_deregister(&ixp4xx_wdt_miscdev);
-}
+ iwdt = devm_kzalloc(dev, sizeof(*iwdt), GFP_KERNEL);
+ if (!iwdt)
+ return -ENOMEM;
+ iwdt->base = dev->platform_data;
+ /*
+ * Retrieve rate from a fixed clock from the device tree if
+ * the parent has that, else use the default clock rate.
+ */
+ clk = devm_clk_get(dev->parent, NULL);
+ if (!IS_ERR(clk)) {
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ return ret;
+ ret = devm_add_action_or_reset(dev, ixp4xx_clock_action, clk);
+ if (ret)
+ return ret;
+ iwdt->rate = clk_get_rate(clk);
+ }
+ if (!iwdt->rate)
+ iwdt->rate = IXP4XX_TIMER_FREQ;
-module_init(ixp4xx_wdt_init);
-module_exit(ixp4xx_wdt_exit);
+ iwdt->wdd.info = &ixp4xx_wdt_info;
+ iwdt->wdd.ops = &ixp4xx_wdt_ops;
+ iwdt->wdd.min_timeout = 1;
+ iwdt->wdd.max_timeout = U32_MAX / iwdt->rate;
+ iwdt->wdd.parent = dev;
+ /* Default to 60 seconds */
+ iwdt->wdd.timeout = 60U;
+ watchdog_init_timeout(&iwdt->wdd, 0, dev);
-MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
-MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
+ if (__raw_readl(iwdt->base + IXP4XX_OSST_OFFSET) &
+ IXP4XX_OSST_TIMER_WARM_RESET)
+ iwdt->wdd.bootstatus = WDIOF_CARDRESET;
+
+ ret = devm_watchdog_register_device(dev, &iwdt->wdd);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "IXP4xx watchdog available\n");
-module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
+ return 0;
+}
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+static struct platform_driver ixp4xx_wdt_driver = {
+ .probe = ixp4xx_wdt_probe,
+ .driver = {
+ .name = "ixp4xx-watchdog",
+ },
+};
+module_platform_driver(ixp4xx_wdt_driver);
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / blobdiff