--- /dev/null
+/*
+ * Copyright (C) 2016 National Instruments Corp.
+ *
+ * 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.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define LOCK 0xA5
+#define UNLOCK 0x5A
+
+#define WDT_CTRL_RESET_EN BIT(7)
+#define WDT_RELOAD_PORT_EN BIT(7)
+
+#define WDT_CTRL 1
+#define WDT_RELOAD_CTRL 2
+#define WDT_PRESET_PRESCALE 4
+#define WDT_REG_LOCK 5
+#define WDT_COUNT 6
+#define WDT_RELOAD_PORT 7
+
+#define WDT_MIN_TIMEOUT 1
+#define WDT_MAX_TIMEOUT 464
+#define WDT_DEFAULT_TIMEOUT 80
+
+#define WDT_MAX_COUNTER 15
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (default="
+ __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started. (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct nic7018_wdt {
+ u16 io_base;
+ u32 period;
+ struct watchdog_device wdd;
+};
+
+struct nic7018_config {
+ u32 period;
+ u8 divider;
+};
+
+static const struct nic7018_config nic7018_configs[] = {
+ { 2, 4 },
+ { 32, 5 },
+};
+
+static inline u32 nic7018_timeout(u32 period, u8 counter)
+{
+ return period * counter - period / 2;
+}
+
+static const struct nic7018_config *nic7018_get_config(u32 timeout,
+ u8 *counter)
+{
+ const struct nic7018_config *config;
+ u8 count;
+
+ if (timeout < 30 && timeout != 16) {
+ config = &nic7018_configs[0];
+ count = timeout / 2 + 1;
+ } else {
+ config = &nic7018_configs[1];
+ count = DIV_ROUND_UP(timeout + 16, 32);
+
+ if (count > WDT_MAX_COUNTER)
+ count = WDT_MAX_COUNTER;
+ }
+ *counter = count;
+ return config;
+}
+
+static int nic7018_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ const struct nic7018_config *config;
+ u8 counter;
+
+ config = nic7018_get_config(timeout, &counter);
+
+ outb(counter << 4 | config->divider,
+ wdt->io_base + WDT_PRESET_PRESCALE);
+
+ wdd->timeout = nic7018_timeout(config->period, counter);
+ wdt->period = config->period;
+
+ return 0;
+}
+
+static int nic7018_start(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ u8 control;
+
+ nic7018_set_timeout(wdd, wdd->timeout);
+
+ control = inb(wdt->io_base + WDT_RELOAD_CTRL);
+ outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);
+
+ outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+ control = inb(wdt->io_base + WDT_CTRL);
+ outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);
+
+ return 0;
+}
+
+static int nic7018_stop(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ outb(0, wdt->io_base + WDT_CTRL);
+ outb(0, wdt->io_base + WDT_RELOAD_CTRL);
+ outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
+
+ return 0;
+}
+
+static int nic7018_ping(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+ return 0;
+}
+
+static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ u8 count;
+
+ count = inb(wdt->io_base + WDT_COUNT) & 0xF;
+ if (!count)
+ return 0;
+
+ return nic7018_timeout(wdt->period, count);
+}
+
+static const struct watchdog_info nic7018_wdd_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "NIC7018 Watchdog",
+};
+
+static const struct watchdog_ops nic7018_wdd_ops = {
+ .owner = THIS_MODULE,
+ .start = nic7018_start,
+ .stop = nic7018_stop,
+ .ping = nic7018_ping,
+ .set_timeout = nic7018_set_timeout,
+ .get_timeleft = nic7018_get_timeleft,
+};
+
+static int nic7018_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct watchdog_device *wdd;
+ struct nic7018_wdt *wdt;
+ struct resource *io_rc;
+ int ret;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, wdt);
+
+ io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!io_rc) {
+ dev_err(dev, "missing IO resources\n");
+ return -EINVAL;
+ }
+
+ if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
+ KBUILD_MODNAME)) {
+ dev_err(dev, "failed to get IO region\n");
+ return -EBUSY;
+ }
+
+ wdt->io_base = io_rc->start;
+ wdd = &wdt->wdd;
+ wdd->info = &nic7018_wdd_info;
+ wdd->ops = &nic7018_wdd_ops;
+ wdd->min_timeout = WDT_MIN_TIMEOUT;
+ wdd->max_timeout = WDT_MAX_TIMEOUT;
+ wdd->timeout = WDT_DEFAULT_TIMEOUT;
+ wdd->parent = dev;
+
+ watchdog_set_drvdata(wdd, wdt);
+ watchdog_set_nowayout(wdd, nowayout);
+
+ ret = watchdog_init_timeout(wdd, timeout, dev);
+ if (ret)
+ dev_warn(dev, "unable to set timeout value, using default\n");
+
+ /* Unlock WDT register */
+ outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
+
+ ret = watchdog_register_device(wdd);
+ if (ret) {
+ outb(LOCK, wdt->io_base + WDT_REG_LOCK);
+ dev_err(dev, "failed to register watchdog\n");
+ return ret;
+ }
+
+ dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
+ wdt->io_base, timeout, nowayout);
+ return 0;
+}
+
+static int nic7018_remove(struct platform_device *pdev)
+{
+ struct nic7018_wdt *wdt = platform_get_drvdata(pdev);
+
+ watchdog_unregister_device(&wdt->wdd);
+
+ /* Lock WDT register */
+ outb(LOCK, wdt->io_base + WDT_REG_LOCK);
+
+ return 0;
+}
+
+static const struct acpi_device_id nic7018_device_ids[] = {
+ {"NIC7018", 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);
+
+static struct platform_driver watchdog_driver = {
+ .probe = nic7018_probe,
+ .remove = nic7018_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .acpi_match_table = ACPI_PTR(nic7018_device_ids),
+ },
+};
+
+module_platform_driver(watchdog_driver);
+
+MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver");
+MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff