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Release 4.11 drivers/watchdog/nic7018_wdt.c

Directory: drivers/watchdog
/*
 * 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; }

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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; }

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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; }

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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; }

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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; }

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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; }

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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); }

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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; }

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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; }

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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");

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Directory: drivers/watchdog
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