diff options
Diffstat (limited to 'drivers/watchdog/nic7018_wdt.c')
| -rw-r--r-- | drivers/watchdog/nic7018_wdt.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/drivers/watchdog/nic7018_wdt.c b/drivers/watchdog/nic7018_wdt.c new file mode 100644 index 000000000..dcd265685 --- /dev/null +++ b/drivers/watchdog/nic7018_wdt.c @@ -0,0 +1,265 @@ +/* + * 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"); |