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From:   Jerry Hoemann <jerry.hoemann@hpe.com>
To:     wim@linux-watchdog.org, linux@roeck-us.net
Cc:     linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
        rwright@hpe.com, maurice.a.saldivar@hpe.com,
        Jerry Hoemann <jerry.hoemann@hpe.com>
Subject: [PATCH 06/10] watchdog/hpwdt: Modify to use watchdog core.
Date:   Tue,  6 Feb 2018 15:58:51 -0700
Message-Id: <20180206225855.30582-7-jerry.hoemann@hpe.com>
In-Reply-To: <20180206225855.30582-1-jerry.hoemann@hpe.com>
References: <20180206225855.30582-1-jerry.hoemann@hpe.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Follow Documentation/watchdog/convert_drivers_to_kernel_api.txt to
convert hpwdt from legacy watchdog driver to use the watchdog core.

Removed functions: hpwdt_open, hpwdt_release, hpwdt_write, hpwdt_ioctl
Removed data structures: hpwdt_fops, hpwdt_miscdev, watchdog_device
Modified functions: hpwdt_start, hpwdt_stop, hpwdt_ping, hpwdt_gettimeleft
Added functions: hpwdt_settimeout
Added structures: watchdog_device

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
---
 drivers/watchdog/hpwdt.c | 254 ++++++++++++-----------------------------------
 1 file changed, 66 insertions(+), 188 deletions(-)

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 3fae3119369f..a8e5c6542406 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -14,18 +14,13 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/device.h>
-#include <linux/fs.h>
-#include <linux/io.h>
-#include <linux/bitops.h>
 #include <linux/kernel.h>
-#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/pci.h>
-#include <linux/pci_ids.h>
 #include <linux/types.h>
-#include <linux/uaccess.h>
 #include <linux/watchdog.h>
+
 #include <asm/nmi.h>
 
 #define HPWDT_VERSION			"1.4.0"
@@ -38,8 +33,6 @@ static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
 static unsigned int reload;			/* the computed soft_margin */
 static bool nowayout = WATCHDOG_NOWAYOUT;
 static unsigned int allow_kdump = 1;
-static char expect_release;
-static unsigned long hpwdt_is_open;
 
 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
 static unsigned long __iomem *hpwdt_nmistat;
@@ -53,53 +46,58 @@ static const struct pci_device_id hpwdt_devices[] = {
 };
 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
 
+static struct watchdog_device hpwdt_dev;
 
 /*
  *	Watchdog operations
  */
-static void hpwdt_start(void)
+static int hpwdt_start(struct watchdog_device *dev)
 {
-	reload = SECS_TO_TICKS(soft_margin);
+	reload = SECS_TO_TICKS(dev->timeout);
+
 	iowrite16(reload, hpwdt_timer_reg);
 	iowrite8(0x85, hpwdt_timer_con);
+
+	return 0;
 }
 
-static void hpwdt_stop(void)
+static int hpwdt_stop(struct watchdog_device *dev)
 {
 	unsigned long data;
 
 	data = ioread8(hpwdt_timer_con);
 	data &= 0xFE;
 	iowrite8(data, hpwdt_timer_con);
+	return 0;
 }
 
-static void hpwdt_ping(void)
-{
-	iowrite16(reload, hpwdt_timer_reg);
-}
-
-static int hpwdt_change_timer(int new_margin)
+static int hpwdt_ping(struct watchdog_device *dev)
 {
-	if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
-		pr_warn("New value passed in is invalid: %d seconds\n",
-			new_margin);
-		return -EINVAL;
-	}
+	reload = SECS_TO_TICKS(dev->timeout);
 
-	soft_margin = new_margin;
-	pr_debug("New timer passed in is %d seconds\n", new_margin);
-	reload = SECS_TO_TICKS(soft_margin);
+	iowrite16(reload, hpwdt_timer_reg);
 
 	return 0;
 }
 
-static int hpwdt_time_left(void)
+static unsigned int hpwdt_gettimeleft(struct watchdog_device *dev)
 {
 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
 }
 
+static int hpwdt_settimeout(struct watchdog_device *dev, unsigned int val)
+{
+	pr_debug("settimeout = %d\n", val);
+
+	soft_margin = dev->timeout = val;
+	hpwdt_ping(dev);
+
+	return 0;
+}
+
 #ifdef CONFIG_HPWDT_NMI_DECODING	/* { */
-static int hpwdt_my_nmi(void)
+
+static unsigned int hpwdt_my_nmi(void)
 {
 	return ioread8(hpwdt_nmistat) & 0x6;
 }
@@ -126,8 +124,10 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 	if ((ulReason == NMI_UNKNOWN) && !mynmi)
 		return NMI_DONE;
 
+	pr_debug("nmi: ulReason=%d, mynmi=0x%0x\n", ulReason, mynmi);
+
 	if (allow_kdump)
-		hpwdt_stop();
+		hpwdt_stop(&hpwdt_dev);
 
 	panic_msg[0] = hexdigit((mynmi>>4)&0xf);
 	panic_msg[1] = hexdigit(mynmi&0xf);
@@ -138,68 +138,6 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 }
 #endif					/* } */
 
-/*
- *	/dev/watchdog handling
- */
-static int hpwdt_open(struct inode *inode, struct file *file)
-{
-	/* /dev/watchdog can only be opened once */
-	if (test_and_set_bit(0, &hpwdt_is_open))
-		return -EBUSY;
-
-	/* Start the watchdog */
-	hpwdt_start();
-	hpwdt_ping();
-
-	return nonseekable_open(inode, file);
-}
-
-static int hpwdt_release(struct inode *inode, struct file *file)
-{
-	/* Stop the watchdog */
-	if (expect_release == 42) {
-		hpwdt_stop();
-	} else {
-		pr_crit("Unexpected close, not stopping watchdog!\n");
-		hpwdt_ping();
-	}
-
-	expect_release = 0;
-
-	/* /dev/watchdog is being closed, make sure it can be re-opened */
-	clear_bit(0, &hpwdt_is_open);
-
-	return 0;
-}
-
-static ssize_t hpwdt_write(struct file *file, const char __user *data,
-	size_t len, loff_t *ppos)
-{
-	/* See if we got the magic character 'V' and reload the timer */
-	if (len) {
-		if (!nowayout) {
-			size_t i;
-
-			/* note: just in case someone wrote the magic character
-			 * five months ago... */
-			expect_release = 0;
-
-			/* scan to see whether or not we got the magic char. */
-			for (i = 0; i != len; i++) {
-				char c;
-				if (get_user(c, data + i))
-					return -EFAULT;
-				if (c == 'V')
-					expect_release = 42;
-			}
-		}
-
-		/* someone wrote to us, we should reload the timer */
-		hpwdt_ping();
-	}
-
-	return len;
-}
 
 static const struct watchdog_info hpwdt_info = {
 	.options	= WDIOF_SETTIMEOUT    |
@@ -208,92 +146,13 @@ static const struct watchdog_info hpwdt_info = {
 	.identity	= "HPE iLO2+ HW Watchdog Timer",
 };
 
-static long hpwdt_ioctl(struct file *file, unsigned int cmd,
-	unsigned long arg)
-{
-	void __user *argp = (void __user *)arg;
-	int __user *p = argp;
-	int new_margin, options;
-	int ret = -ENOTTY;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		ret = 0;
-		if (copy_to_user(argp, &hpwdt_info, sizeof(hpwdt_info)))
-			ret = -EFAULT;
-		break;
-
-	case WDIOC_GETSTATUS:
-	case WDIOC_GETBOOTSTATUS:
-		ret = put_user(0, p);
-		break;
-
-	case WDIOC_KEEPALIVE:
-		hpwdt_ping();
-		ret = 0;
-		break;
-
-	case WDIOC_SETOPTIONS:
-		ret = get_user(options, p);
-		if (ret)
-			break;
-
-		if (options & WDIOS_DISABLECARD)
-			hpwdt_stop();
-
-		if (options & WDIOS_ENABLECARD) {
-			hpwdt_start();
-			hpwdt_ping();
-		}
-		break;
-
-	case WDIOC_SETTIMEOUT:
-		ret = get_user(new_margin, p);
-		if (ret)
-			break;
-
-		ret = hpwdt_change_timer(new_margin);
-		if (ret)
-			break;
-
-		hpwdt_ping();
-		/* Fall */
-	case WDIOC_GETTIMEOUT:
-		ret = put_user(soft_margin, p);
-		break;
-
-	case WDIOC_GETTIMELEFT:
-		ret = put_user(hpwdt_time_left(), p);
-		break;
-	}
-	return ret;
-}
-
-/*
- *	Kernel interfaces
- */
-static const struct file_operations hpwdt_fops = {
-	.owner = THIS_MODULE,
-	.llseek = no_llseek,
-	.write = hpwdt_write,
-	.unlocked_ioctl = hpwdt_ioctl,
-	.open = hpwdt_open,
-	.release = hpwdt_release,
-};
-
-static struct miscdevice hpwdt_miscdev = {
-	.minor = WATCHDOG_MINOR,
-	.name = "watchdog",
-	.fops = &hpwdt_fops,
-};
-
 /*
  *	Init & Exit
  */
 
-
 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 {
+#ifdef CONFIG_HPWDT_NMI_DECODING	/* { */
 	int retval;
 	/*
 	 * Only one function can register for NMI_UNKNOWN
@@ -308,10 +167,7 @@ static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 	if (retval)
 		goto error2;
 
-	dev_info(&dev->dev,
-			"HPE Watchdog Timer Driver: NMI decoding initialized"
-			", allow kernel dump: %s (default = 1/ON)\n",
-			(allow_kdump == 0) ? "OFF" : "ON");
+	dev_info(&dev->dev, "HPE Watchdog Timer Driver: NMI decoding initialized");
 	return 0;
 
 error2:
@@ -323,6 +179,8 @@ static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 		"Unable to register a die notifier (err=%d).\n",
 		retval);
 	return retval;
+#endif					/* } */
+	return 0;
 }
 
 static void hpwdt_exit_nmi_decoding(void)
@@ -376,31 +234,32 @@ static int hpwdt_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 	hpwdt_timer_con = pci_mem_addr + 0x72;
 
 	/* Make sure that timer is disabled until /dev/watchdog is opened */
-	hpwdt_stop();
-
-	/* Make sure that we have a valid soft_margin */
-	if (hpwdt_change_timer(soft_margin))
-		hpwdt_change_timer(DEFAULT_MARGIN);
+	hpwdt_stop(&hpwdt_dev);
 
 	/* Initialize NMI Decoding functionality */
 	retval = hpwdt_init_nmi_decoding(dev);
 	if (retval != 0)
 		goto error_init_nmi_decoding;
 
-	retval = misc_register(&hpwdt_miscdev);
+	retval = watchdog_register_device(&hpwdt_dev);
 	if (retval < 0) {
-		dev_warn(&dev->dev,
-			"Unable to register miscdev on minor=%d (err=%d).\n",
-			WATCHDOG_MINOR, retval);
-		goto error_misc_register;
+		dev_warn(&dev->dev, "Unable to register hpe watchdog (err=%d).\n", retval);
+		goto error_wd_register;
+	}
+
+	watchdog_set_nowayout(&hpwdt_dev, nowayout);
+	if (watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL)) {
+		dev_warn(&dev->dev, "Invalid soft_margin: %d. Using default\n", soft_margin);
+		soft_margin = DEFAULT_MARGIN;
 	}
 
 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
 			", timer margin: %d seconds (nowayout=%d).\n",
-			HPWDT_VERSION, soft_margin, nowayout);
+			HPWDT_VERSION, hpwdt_dev.timeout, nowayout);
+
 	return 0;
 
-error_misc_register:
+error_wd_register:
 	hpwdt_exit_nmi_decoding();
 error_init_nmi_decoding:
 	pci_iounmap(dev, pci_mem_addr);
@@ -412,9 +271,9 @@ static int hpwdt_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 static void hpwdt_exit(struct pci_dev *dev)
 {
 	if (!nowayout)
-		hpwdt_stop();
+		hpwdt_stop(&hpwdt_dev);
 
-	misc_deregister(&hpwdt_miscdev);
+	watchdog_unregister_device(&hpwdt_dev);
 	hpwdt_exit_nmi_decoding();
 	pci_iounmap(dev, pci_mem_addr);
 	pci_disable_device(dev);
@@ -427,6 +286,25 @@ static struct pci_driver hpwdt_driver = {
 	.remove		= hpwdt_exit,
 };
 
+
+static const struct watchdog_ops hpwdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= hpwdt_start,
+	.stop		= hpwdt_stop,
+	.ping		= hpwdt_ping,
+	.set_timeout	= hpwdt_settimeout,
+	.get_timeleft	= hpwdt_gettimeleft,
+};
+
+static struct watchdog_device hpwdt_dev = {
+	.info		= &hpwdt_info,
+	.ops		= &hpwdt_ops,
+	.min_timeout	= 1,
+	.max_timeout	= HPWDT_MAX_TIMER,
+	.timeout	= DEFAULT_MARGIN,
+};
+
+
 MODULE_AUTHOR("Jerry Hoemann");
 MODULE_DESCRIPTION("hpe watchdog driver");
 MODULE_LICENSE("GPL");
-- 
2.13.6