[WATCHDOG] ep93xx: implemented watchdog timer driver for TS-72xx SBCs (c90bf2aa) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/watchdog/Kconfig

+11 −0

Original line number	Original line	Diff line number	Diff line
	@@ -289,6 +289,17 @@ config ADX_WATCHDOG
	Say Y here if you want support for the watchdog timer on Avionic		Say Y here if you want support for the watchdog timer on Avionic
	Design Xanthos boards.		Design Xanthos boards.

			config TS72XX_WATCHDOG
			tristate "TS-72XX SBC Watchdog"
			depends on MACH_TS72XX
			help
			Technologic Systems TS-7200, TS-7250 and TS-7260 boards have
			watchdog timer implemented in a external CPLD chip. Say Y here
			if you want to support for the watchdog timer on TS-72XX boards.

			To compile this driver as a module, choose M here: the
			module will be called ts72xx_wdt.

	# AVR32 Architecture		# AVR32 Architecture

	config AT32AP700X_WDT		config AT32AP700X_WDT

drivers/watchdog/Makefile

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -46,6 +46,7 @@ obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
	obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o		obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
	obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o		obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
	obj-$(CONFIG_ADX_WATCHDOG) += adx_wdt.o		obj-$(CONFIG_ADX_WATCHDOG) += adx_wdt.o
			obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o

	# AVR32 Architecture		# AVR32 Architecture
	obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o		obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o

drivers/watchdog/ts72xx_wdt.c

0 → 100644

+516 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Watchdog driver for Technologic Systems TS-72xx based SBCs
			* (TS-7200, TS-7250 and TS-7260). These boards have external
			* glue logic CPLD chip, which includes programmable watchdog
			* timer.
			*
			* Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi>
			*
			* This driver is based on ep93xx_wdt and wm831x_wdt drivers.
			*
			* This file is licensed under the terms of the GNU General Public
			* License version 2. This program is licensed "as is" without any
			* warranty of any kind, whether express or implied.
			*/

			#include <linux/fs.h>
			#include <linux/io.h>
			#include <linux/module.h>
			#include <linux/moduleparam.h>
			#include <linux/miscdevice.h>
			#include <linux/mutex.h>
			#include <linux/platform_device.h>
			#include <linux/watchdog.h>
			#include <linux/uaccess.h>

			#define TS72XX_WDT_FEED_VAL 0x05
			#define TS72XX_WDT_DEFAULT_TIMEOUT 8

			static int timeout = TS72XX_WDT_DEFAULT_TIMEOUT;
			module_param(timeout, int, 0);
			MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. "
			"(1 <= timeout <= 8, default="
			__MODULE_STRING(TS72XX_WDT_DEFAULT_TIMEOUT)
			")");

			static int nowayout = WATCHDOG_NOWAYOUT;
			module_param(nowayout, int, 0);
			MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

			/**
			* struct ts72xx_wdt - watchdog control structure
			* @lock: lock that protects this structure
			* @regval: watchdog timeout value suitable for control register
			* @flags: flags controlling watchdog device state
			* @control_reg: watchdog control register
			* @feed_reg: watchdog feed register
			* @pdev: back pointer to platform dev
			*/
			struct ts72xx_wdt {
			struct mutex lock;
			int regval;

			#define TS72XX_WDT_BUSY_FLAG 1
			#define TS72XX_WDT_EXPECT_CLOSE_FLAG 2
			int flags;

			void __iomem *control_reg;
			void __iomem *feed_reg;

			struct platform_device *pdev;
			};

			struct platform_device *ts72xx_wdt_pdev;

			/*
			* TS-72xx Watchdog supports following timeouts (value written
			* to control register):
			* value description
			* -------------------------
			* 0x00 watchdog disabled
			* 0x01 250ms
			* 0x02 500ms
			* 0x03 1s
			* 0x04 reserved
			* 0x05 2s
			* 0x06 4s
			* 0x07 8s
			*
			* Timeouts below 1s are not very usable so we don't
			* allow them at all.
			*
			* We provide two functions that convert between these:
			* timeout_to_regval() and regval_to_timeout().
			*/
			static const struct {
			int timeout;
			int regval;
			} ts72xx_wdt_map[] = {
			{ 1, 3 },
			{ 2, 5 },
			{ 4, 6 },
			{ 8, 7 },
			};

			/**
			* timeout_to_regval() - converts given timeout to control register value
			* @new_timeout: timeout in seconds to be converted
			*
			* Function converts given @new_timeout into valid value that can
			* be programmed into watchdog control register. When conversion is
			* not possible, function returns %-EINVAL.
			*/
			static int timeout_to_regval(int new_timeout)
			{
			int i;

			/* first limit it to 1 - 8 seconds */
			new_timeout = clamp_val(new_timeout, 1, 8);

			for (i = 0; i < ARRAY_SIZE(ts72xx_wdt_map); i++) {
			if (ts72xx_wdt_map[i].timeout >= new_timeout)
			return ts72xx_wdt_map[i].regval;
			}

			return -EINVAL;
			}

			/**
			* regval_to_timeout() - converts control register value to timeout
			* @regval: control register value to be converted
			*
			* Function converts given @regval to timeout in seconds (1, 2, 4 or 8).
			* If @regval cannot be converted, function returns %-EINVAL.
			*/
			static int regval_to_timeout(int regval)
			{
			int i;

			for (i = 0; i < ARRAY_SIZE(ts72xx_wdt_map); i++) {
			if (ts72xx_wdt_map[i].regval == regval)
			return ts72xx_wdt_map[i].timeout;
			}

			return -EINVAL;
			}

			/**
			* ts72xx_wdt_kick() - kick the watchdog
			* @wdt: watchdog to be kicked
			*
			* Called with @wdt->lock held.
			*/
			static inline void ts72xx_wdt_kick(struct ts72xx_wdt *wdt)
			{
			__raw_writeb(TS72XX_WDT_FEED_VAL, wdt->feed_reg);
			}

			/**
			* ts72xx_wdt_start() - starts the watchdog timer
			* @wdt: watchdog to be started
			*
			* This function programs timeout to watchdog timer
			* and starts it.
			*
			* Called with @wdt->lock held.
			*/
			static void ts72xx_wdt_start(struct ts72xx_wdt *wdt)
			{
			/*
			* To program the wdt, it first must be "fed" and
			* only after that (within 30 usecs) the configuration
			* can be changed.
			*/
			ts72xx_wdt_kick(wdt);
			__raw_writeb((u8)wdt->regval, wdt->control_reg);
			}

			/**
			* ts72xx_wdt_stop() - stops the watchdog timer
			* @wdt: watchdog to be stopped
			*
			* Called with @wdt->lock held.
			*/
			static void ts72xx_wdt_stop(struct ts72xx_wdt *wdt)
			{
			ts72xx_wdt_kick(wdt);
			__raw_writeb(0, wdt->control_reg);
			}

			static int ts72xx_wdt_open(struct inode inode, struct file file)
			{
			struct ts72xx_wdt *wdt = platform_get_drvdata(ts72xx_wdt_pdev);
			int regval;

			/*
			* Try to convert default timeout to valid register
			* value first.
			*/
			regval = timeout_to_regval(timeout);
			if (regval < 0) {
			dev_err(&wdt->pdev->dev,
			"failed to convert timeout (%d) to register value\n",
			timeout);
			return -EINVAL;
			}

			if (mutex_lock_interruptible(&wdt->lock))
			return -ERESTARTSYS;

			if ((wdt->flags & TS72XX_WDT_BUSY_FLAG) != 0) {
			mutex_unlock(&wdt->lock);
			return -EBUSY;
			}

			wdt->flags = TS72XX_WDT_BUSY_FLAG;
			wdt->regval = regval;
			file->private_data = wdt;

			ts72xx_wdt_start(wdt);

			mutex_unlock(&wdt->lock);
			return nonseekable_open(inode, file);
			}

			static int ts72xx_wdt_release(struct inode inode, struct file file)
			{
			struct ts72xx_wdt *wdt = file->private_data;

			if (mutex_lock_interruptible(&wdt->lock))
			return -ERESTARTSYS;

			if ((wdt->flags & TS72XX_WDT_EXPECT_CLOSE_FLAG) != 0) {
			ts72xx_wdt_stop(wdt);
			} else {
			dev_warn(&wdt->pdev->dev,
			"TS-72XX WDT device closed unexpectly. "
			"Watchdog timer will not stop!\n");
			/*
			* Kick it one more time, to give userland some time
			* to recover (for example, respawning the kicker
			* daemon).
			*/
			ts72xx_wdt_kick(wdt);
			}

			wdt->flags = 0;

			mutex_unlock(&wdt->lock);
			return 0;
			}

			static ssize_t ts72xx_wdt_write(struct file *file,
			const char __user *data,
			size_t len,
			loff_t *ppos)
			{
			struct ts72xx_wdt *wdt = file->private_data;

			if (!len)
			return 0;

			if (mutex_lock_interruptible(&wdt->lock))
			return -ERESTARTSYS;

			ts72xx_wdt_kick(wdt);

			/*
			* Support for magic character closing. User process
			* writes 'V' into the device, just before it is closed.
			* This means that we know that the wdt timer can be
			* stopped after user closes the device.
			*/
			if (!nowayout) {
			int i;

			for (i = 0; i < len; i++) {
			char c;

			/* In case it was set long ago */
			wdt->flags &= ~TS72XX_WDT_EXPECT_CLOSE_FLAG;

			if (get_user(c, data + i)) {
			mutex_unlock(&wdt->lock);
			return -EFAULT;
			}
			if (c == 'V') {
			wdt->flags \|= TS72XX_WDT_EXPECT_CLOSE_FLAG;
			break;
			}
			}
			}

			mutex_unlock(&wdt->lock);
			return len;
			}

			static const struct watchdog_info winfo = {
			.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
			WDIOF_MAGICCLOSE,
			.firmware_version = 1,
			.identity = "TS-72XX WDT",
			};

			static long ts72xx_wdt_ioctl(struct file *file, unsigned int cmd,
			unsigned long arg)
			{
			struct ts72xx_wdt *wdt = file->private_data;
			void __user argp = (void __user )arg;
			int __user p = (int __user )argp;
			int error = 0;

			if (mutex_lock_interruptible(&wdt->lock))
			return -ERESTARTSYS;

			switch (cmd) {
			case WDIOC_GETSUPPORT:
			error = copy_to_user(argp, &winfo, sizeof(winfo));
			break;

			case WDIOC_KEEPALIVE:
			ts72xx_wdt_kick(wdt);
			break;

			case WDIOC_SETOPTIONS: {
			int options;

			if (get_user(options, p)) {
			error = -EFAULT;
			break;
			}

			error = -EINVAL;

			if ((options & WDIOS_DISABLECARD) != 0) {
			ts72xx_wdt_stop(wdt);
			error = 0;
			}
			if ((options & WDIOS_ENABLECARD) != 0) {
			ts72xx_wdt_start(wdt);
			error = 0;
			}

			break;
			}

			case WDIOC_SETTIMEOUT: {
			int new_timeout;

			if (get_user(new_timeout, p)) {
			error = -EFAULT;
			} else {
			int regval;

			regval = timeout_to_regval(new_timeout);
			if (regval < 0) {
			error = -EINVAL;
			} else {
			ts72xx_wdt_stop(wdt);
			wdt->regval = regval;
			ts72xx_wdt_start(wdt);
			}
			}
			if (error)
			break;

			/FALLTHROUGH/
			}

			case WDIOC_GETTIMEOUT:
			if (put_user(regval_to_timeout(wdt->regval), p))
			error = -EFAULT;
			break;

			default:
			error = -ENOTTY;
			break;
			}

			mutex_unlock(&wdt->lock);
			return error;
			}

			static const struct file_operations ts72xx_wdt_fops = {
			.owner = THIS_MODULE,
			.llseek = no_llseek,
			.open = ts72xx_wdt_open,
			.release = ts72xx_wdt_release,
			.write = ts72xx_wdt_write,
			.unlocked_ioctl = ts72xx_wdt_ioctl,
			};

			static struct miscdevice ts72xx_wdt_miscdev = {
			.minor = WATCHDOG_MINOR,
			.name = "watchdog",
			.fops = &ts72xx_wdt_fops,
			};

			static __devinit int ts72xx_wdt_probe(struct platform_device *pdev)
			{
			struct ts72xx_wdt *wdt;
			struct resource r1, r2;
			int error = 0;

			wdt = kzalloc(sizeof(struct ts72xx_wdt), GFP_KERNEL);
			if (!wdt) {
			dev_err(&pdev->dev, "failed to allocate memory\n");
			return -ENOMEM;
			}

			r1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
			if (!r1) {
			dev_err(&pdev->dev, "failed to get memory resource\n");
			error = -ENODEV;
			goto fail;
			}

			r1 = request_mem_region(r1->start, resource_size(r1), pdev->name);
			if (!r1) {
			dev_err(&pdev->dev, "cannot request memory region\n");
			error = -EBUSY;
			goto fail;
			}

			wdt->control_reg = ioremap(r1->start, resource_size(r1));
			if (!wdt->control_reg) {
			dev_err(&pdev->dev, "failed to map memory\n");
			error = -ENODEV;
			goto fail_free_control;
			}

			r2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
			if (!r2) {
			dev_err(&pdev->dev, "failed to get memory resource\n");
			error = -ENODEV;
			goto fail_unmap_control;
			}

			r2 = request_mem_region(r2->start, resource_size(r2), pdev->name);
			if (!r2) {
			dev_err(&pdev->dev, "cannot request memory region\n");
			error = -EBUSY;
			goto fail_unmap_control;
			}

			wdt->feed_reg = ioremap(r2->start, resource_size(r2));
			if (!wdt->feed_reg) {
			dev_err(&pdev->dev, "failed to map memory\n");
			error = -ENODEV;
			goto fail_free_feed;
			}

			platform_set_drvdata(pdev, wdt);
			ts72xx_wdt_pdev = pdev;
			wdt->pdev = pdev;
			mutex_init(&wdt->lock);

			error = misc_register(&ts72xx_wdt_miscdev);
			if (error) {
			dev_err(&pdev->dev, "failed to register miscdev\n");
			goto fail_unmap_feed;
			}

			dev_info(&pdev->dev, "TS-72xx Watchdog driver\n");

			return 0;

			fail_unmap_feed:
			platform_set_drvdata(pdev, NULL);
			iounmap(wdt->feed_reg);
			fail_free_feed:
			release_mem_region(r2->start, resource_size(r2));
			fail_unmap_control:
			iounmap(wdt->control_reg);
			fail_free_control:
			release_mem_region(r1->start, resource_size(r1));
			fail:
			kfree(wdt);
			return error;
			}

			static __devexit int ts72xx_wdt_remove(struct platform_device *pdev)
			{
			struct ts72xx_wdt *wdt = platform_get_drvdata(pdev);
			struct resource *res;
			int error;

			error = misc_deregister(&ts72xx_wdt_miscdev);
			platform_set_drvdata(pdev, NULL);

			iounmap(wdt->control_reg);
			res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
			release_mem_region(res->start, resource_size(res));

			iounmap(wdt->feed_reg);
			res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
			release_mem_region(res->start, resource_size(res));

			kfree(wdt);
			return error;
			}

			static struct platform_driver ts72xx_wdt_driver = {
			.probe = ts72xx_wdt_probe,
			.remove = __devexit_p(ts72xx_wdt_remove),
			.driver = {
			.name = "ts72xx-wdt",
			.owner = THIS_MODULE,
			},
			};

			static __init int ts72xx_wdt_init(void)
			{
			return platform_driver_register(&ts72xx_wdt_driver);
			}
			module_init(ts72xx_wdt_init);

			static __exit void ts72xx_wdt_exit(void)
			{
			platform_driver_unregister(&ts72xx_wdt_driver);
			}
			module_exit(ts72xx_wdt_exit);

			MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
			MODULE_DESCRIPTION("TS-72xx SBC Watchdog");
			MODULE_LICENSE("GPL");
			MODULE_ALIAS("platform:ts72xx-wdt");