drivers/watchdog/nic7018_wdt.c - kernel/common - Git at Google

 /*
  * 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 <[email protected]>");
 MODULE_LICENSE("GPL");
	/*
	* 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 <[email protected]>");
	MODULE_LICENSE("GPL");