[WATCHDOG] Pika Warp appliance watchdog timer (618efba9) · Commits · e / devices / android_kernel_teracube_2e

drivers/watchdog/Kconfig

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Original line number	Diff line number	Diff line
		@@ -796,6 +796,14 @@ config MV64X60_WDT
		tristate "MV64X60 (Marvell Discovery) Watchdog Timer"
		depends on MV64X60

		config PIKA_WDT
		tristate "PIKA FPGA Watchdog"
		depends on WARP
		default y
		help
		This enables the watchdog in the PIKA FPGA. Currently used on
		the Warp platform.

		config BOOKE_WDT
		bool "PowerPC Book-E Watchdog Timer"
		depends on BOOKE \|\| 4xx

drivers/watchdog/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -115,6 +115,7 @@ obj-$(CONFIG_GEF_WDT) += gef_wdt.o
		obj-$(CONFIG_MPC5200_WDT) += mpc5200_wdt.o
		obj-$(CONFIG_8xxx_WDT) += mpc8xxx_wdt.o
		obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o
		obj-$(CONFIG_PIKA_WDT) += pika_wdt.o
		obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o

		# PPC64 Architecture

drivers/watchdog/pika_wdt.c

0 → 100644

+301 −0

Original line number	Diff line number	Diff line
		/*
		* PIKA FPGA based Watchdog Timer
		*
		* Copyright (c) 2008 PIKA Technologies
		* Sean MacLennan <smaclennan@pikatech.com>
		*/

		#include <linux/init.h>
		#include <linux/errno.h>
		#include <linux/module.h>
		#include <linux/moduleparam.h>
		#include <linux/types.h>
		#include <linux/kernel.h>
		#include <linux/fs.h>
		#include <linux/miscdevice.h>
		#include <linux/watchdog.h>
		#include <linux/reboot.h>
		#include <linux/jiffies.h>
		#include <linux/timer.h>
		#include <linux/bitops.h>
		#include <linux/uaccess.h>
		#include <linux/io.h>
		#include <linux/of_platform.h>

		#define DRV_NAME "PIKA-WDT"
		#define PFX DRV_NAME ": "

		/* Hardware timeout in seconds */
		#define WDT_HW_TIMEOUT 2

		/* Timer heartbeat (500ms) */
		#define WDT_TIMEOUT (HZ/2)

		/* User land timeout */
		#define WDT_HEARTBEAT 15
		static int heartbeat = WDT_HEARTBEAT;
		module_param(heartbeat, int, 0);
		MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
		"(default = " __MODULE_STRING(WDT_HEARTBEAT) ")");

		static int nowayout = WATCHDOG_NOWAYOUT;
		module_param(nowayout, int, 0);
		MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
		"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

		static struct {
		void __iomem *fpga;
		unsigned long next_heartbeat; /* the next_heartbeat for the timer */
		unsigned long open;
		char expect_close;
		int bootstatus;
		struct timer_list timer; /* The timer that pings the watchdog */
		} pikawdt_private;

		static struct watchdog_info ident = {
		.identity = DRV_NAME,
		.options = WDIOF_CARDRESET \|
		WDIOF_SETTIMEOUT \|
		WDIOF_KEEPALIVEPING \|
		WDIOF_MAGICCLOSE,
		};

		/*
		* Reload the watchdog timer. (ie, pat the watchdog)
		*/
		static inline void pikawdt_reset(void)
		{
		/* -- FPGA: Reset Control Register (32bit R/W) (Offset: 0x14) --
		* Bit 7, WTCHDG_EN: When set to 1, the watchdog timer is enabled.
		* Once enabled, it cannot be disabled. The watchdog can be
		* kicked by performing any write access to the reset
		* control register (this register).
		* Bit 8-11, WTCHDG_TIMEOUT_SEC: Sets the watchdog timeout value in
		* seconds. Valid ranges are 1 to 15 seconds. The value can
		* be modified dynamically.
		*/
		unsigned reset = in_be32(pikawdt_private.fpga + 0x14);
		/* enable with max timeout - 15 seconds */
		reset \|= (1 << 7) + (WDT_HW_TIMEOUT << 8);
		out_be32(pikawdt_private.fpga + 0x14, reset);
		}

		/*
		* Timer tick
		*/
		static void pikawdt_ping(unsigned long data)
		{
		if (time_before(jiffies, pikawdt_private.next_heartbeat) \|\|
		(!nowayout && !pikawdt_private.open)) {
		pikawdt_reset();
		mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT);
		} else
		printk(KERN_CRIT PFX "I will reset your machine !\n");
		}


		static void pikawdt_keepalive(void)
		{
		pikawdt_private.next_heartbeat = jiffies + heartbeat * HZ;
		}

		static void pikawdt_start(void)
		{
		pikawdt_keepalive();
		mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT);
		}

		/*
		* Watchdog device is opened, and watchdog starts running.
		*/
		static int pikawdt_open(struct inode inode, struct file file)
		{
		/* /dev/watchdog can only be opened once */
		if (test_and_set_bit(0, &pikawdt_private.open))
		return -EBUSY;

		pikawdt_start();

		return nonseekable_open(inode, file);
		}

		/*
		* Close the watchdog device.
		*/
		static int pikawdt_release(struct inode inode, struct file file)
		{
		/* stop internal ping */
		if (!pikawdt_private.expect_close)
		del_timer(&pikawdt_private.timer);

		clear_bit(0, &pikawdt_private.open);
		pikawdt_private.expect_close = 0;
		return 0;
		}

		/*
		* Pat the watchdog whenever device is written to.
		*/
		static ssize_t pikawdt_write(struct file file, const char __user data,
		size_t len, loff_t *ppos)
		{
		if (!len)
		return 0;

		/* Scan for magic character */
		if (!nowayout) {
		size_t i;

		pikawdt_private.expect_close = 0;

		for (i = 0; i < len; i++) {
		char c;
		if (get_user(c, data + i))
		return -EFAULT;
		if (c == 'V') {
		pikawdt_private.expect_close = 42;
		break;
		}
		}
		}

		pikawdt_keepalive();

		return len;
		}

		/*
		* Handle commands from user-space.
		*/
		static long pikawdt_ioctl(struct file *file,
		unsigned int cmd, unsigned long arg)
		{
		void __user argp = (void __user )arg;
		int __user *p = argp;
		int new_value;

		switch (cmd) {
		case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;

		case WDIOC_GETSTATUS:
		return put_user(0, p);

		case WDIOC_GETBOOTSTATUS:
		return put_user(pikawdt_private.bootstatus, p);

		case WDIOC_KEEPALIVE:
		pikawdt_keepalive();
		return 0;

		case WDIOC_SETTIMEOUT:
		if (get_user(new_value, p))
		return -EFAULT;

		heartbeat = new_value;
		pikawdt_keepalive();

		return put_user(new_value, p); /* return current value */

		case WDIOC_GETTIMEOUT:
		return put_user(heartbeat, p);
		}
		return -ENOTTY;
		}


		static const struct file_operations pikawdt_fops = {
		.owner = THIS_MODULE,
		.llseek = no_llseek,
		.open = pikawdt_open,
		.release = pikawdt_release,
		.write = pikawdt_write,
		.unlocked_ioctl = pikawdt_ioctl,
		};

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

		static int __init pikawdt_init(void)
		{
		struct device_node *np;
		void __iomem *fpga;
		static u32 post1;
		int ret;

		np = of_find_compatible_node(NULL, NULL, "pika,fpga");
		if (np == NULL) {
		printk(KERN_ERR PFX "Unable to find fpga.\n");
		return -ENOENT;
		}

		pikawdt_private.fpga = of_iomap(np, 0);
		of_node_put(np);
		if (pikawdt_private.fpga == NULL) {
		printk(KERN_ERR PFX "Unable to map fpga.\n");
		return -ENOMEM;
		}

		ident.firmware_version = in_be32(pikawdt_private.fpga + 0x1c) & 0xffff;

		/* POST information is in the sd area. */
		np = of_find_compatible_node(NULL, NULL, "pika,fpga-sd");
		if (np == NULL) {
		printk(KERN_ERR PFX "Unable to find fpga-sd.\n");
		ret = -ENOENT;
		goto out;
		}

		fpga = of_iomap(np, 0);
		of_node_put(np);
		if (fpga == NULL) {
		printk(KERN_ERR PFX "Unable to map fpga-sd.\n");
		ret = -ENOMEM;
		goto out;
		}

		/* -- FPGA: POST Test Results Register 1 (32bit R/W) (Offset: 0x4040) --
		* Bit 31, WDOG: Set to 1 when the last reset was caused by a watchdog
		* timeout.
		*/
		post1 = in_be32(fpga + 0x40);
		if (post1 & 0x80000000)
		pikawdt_private.bootstatus = WDIOF_CARDRESET;

		iounmap(fpga);

		setup_timer(&pikawdt_private.timer, pikawdt_ping, 0);

		ret = misc_register(&pikawdt_miscdev);
		if (ret) {
		printk(KERN_ERR PFX "Unable to register miscdev.\n");
		goto out;
		}

		printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
		heartbeat, nowayout);
		return 0;

		out:
		iounmap(pikawdt_private.fpga);
		return ret;
		}

		static void __exit pikawdt_exit(void)
		{
		misc_deregister(&pikawdt_miscdev);

		iounmap(pikawdt_private.fpga);
		}

		module_init(pikawdt_init);
		module_exit(pikawdt_exit);

		MODULE_AUTHOR("Sean MacLennan <smaclennan@pikatech.com>");
		MODULE_DESCRIPTION("PIKA FPGA based Watchdog Timer");
		MODULE_LICENSE("GPL");
		MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);