| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2016 National Instruments Corp. |
| */ |
| |
| #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); |
| watchdog_init_timeout(wdd, timeout, dev); |
| |
| /* 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); |
| 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"); |