[PATCH 1/1] watchdog: repair pnx833x_wdt

From: Sergey Yasinsky
Date: Wed Oct 14 2020 - 10:57:12 EST


Using watchdog core functions instead of miscdevice.

Signed-off-by: Sergey Yasinsky <seregajsv@xxxxxxxxx>
---
drivers/watchdog/Kconfig | 2 +-
drivers/watchdog/pnx833x_wdt.c | 219 ++++++++-------------------------
2 files changed, 53 insertions(+), 168 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index ab7aad5a1e69..e9b86dbbb8fa 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1686,7 +1686,7 @@ config WDT_MTX1
config PNX833X_WDT
tristate "PNX833x Hardware Watchdog"
depends on SOC_PNX8335
- depends on BROKEN
+ select WATCHDOG_CORE
help
Hardware driver for the PNX833x's watchdog. This is a
watchdog timer that will reboot the machine after a programmable
diff --git a/drivers/watchdog/pnx833x_wdt.c b/drivers/watchdog/pnx833x_wdt.c
index 4097d076aab8..4ec852c423da 100644
--- a/drivers/watchdog/pnx833x_wdt.c
+++ b/drivers/watchdog/pnx833x_wdt.c
@@ -17,21 +17,11 @@

#include <linux/module.h>
#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/miscdevice.h>
#include <linux/watchdog.h>
-#include <linux/notifier.h>
-#include <linux/reboot.h>
-#include <linux/init.h>
#include <asm/mach-pnx833x/pnx833x.h>

-#define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */
+#define WATCHDOG_DEFAULT_TIMEOUT 30
#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
-#define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY)
-#define PNX_TIMEOUT_VALUE 2040000000U

/** CONFIG block */
#define PNX833X_CONFIG (0x07000U)
@@ -43,40 +33,37 @@
#define PNX833X_RESET (0x08000U)
#define PNX833X_RESET_CONFIG (0x08)

-static int pnx833x_wdt_alive;
+struct pnx833x_wdt {
+ struct watchdog_device wdd;
+};

-/* Set default timeout in MHZ.*/
-static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT;
+/* Set default timeout */
+static int pnx833x_wdt_timeout = WATCHDOG_DEFAULT_TIMEOUT;
module_param(pnx833x_wdt_timeout, int, 0);
-MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
- __MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds).");
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
+ __MODULE_STRING(WATCHDOG_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) ")");

-#define START_DEFAULT 1
-static int start_enabled = START_DEFAULT;
-module_param(start_enabled, int, 0);
-MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
- "(default=" __MODULE_STRING(START_DEFAULT) ")");
-
-static void pnx833x_wdt_start(void)
+static int pnx833x_wdt_start(struct watchdog_device *wdd)
{
/* Enable watchdog causing reset. */
PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
/* Set timeout.*/
- PNX833X_REG(PNX833X_CONFIG +
- PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) =
+ wdd->timeout * WATCHDOG_COUNT_FREQUENCY;
/* Enable watchdog. */
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;

pr_info("Started watchdog timer\n");
+ return 0;
}

-static void pnx833x_wdt_stop(void)
+static int pnx833x_wdt_stop(struct watchdog_device *wdd)
{
/* Disable watchdog causing reset. */
PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
@@ -85,149 +72,54 @@ static void pnx833x_wdt_stop(void)
PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;

pr_info("Stopped watchdog timer\n");
-}
-
-static void pnx833x_wdt_ping(void)
-{
- PNX833X_REG(PNX833X_CONFIG +
- PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
-}
-
-/*
- * Allow only one person to hold it open
- */
-static int pnx833x_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(0, &pnx833x_wdt_alive))
- return -EBUSY;
-
- if (nowayout)
- __module_get(THIS_MODULE);
-
- /* Activate timer */
- if (!start_enabled)
- pnx833x_wdt_start();
-
- pnx833x_wdt_ping();
-
- pr_info("Started watchdog timer\n");
-
- return stream_open(inode, file);
-}
-
-static int pnx833x_wdt_release(struct inode *inode, struct file *file)
-{
- /* Shut off the timer.
- * Lock it in if it's a module and we defined ...NOWAYOUT */
- if (!nowayout)
- pnx833x_wdt_stop(); /* Turn the WDT off */
-
- clear_bit(0, &pnx833x_wdt_alive);
return 0;
}

-static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+static int pnx833x_wdt_ping(struct watchdog_device *wdd)
{
- /* Refresh the timer. */
- if (len)
- pnx833x_wdt_ping();
+ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) =
+ wdd->timeout * WATCHDOG_COUNT_FREQUENCY;

- return len;
+ return 0;
}

-static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
+static int pnx833x_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
- int options, new_timeout = 0;
- uint32_t timeout, timeout_left = 0;
-
- static const struct watchdog_info ident = {
- .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
- .firmware_version = 0,
- .identity = "Hardware Watchdog for PNX833x",
- };
-
- switch (cmd) {
- default:
- return -ENOTTY;
-
- case WDIOC_GETSUPPORT:
- if (copy_to_user((struct watchdog_info *)arg,
- &ident, sizeof(ident)))
- return -EFAULT;
- return 0;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, (int *)arg);
-
- case WDIOC_SETOPTIONS:
- if (get_user(options, (int *)arg))
- return -EFAULT;
-
- if (options & WDIOS_DISABLECARD)
- pnx833x_wdt_stop();
-
- if (options & WDIOS_ENABLECARD)
- pnx833x_wdt_start();
-
- return 0;
-
- case WDIOC_KEEPALIVE:
- pnx833x_wdt_ping();
- return 0;
-
- case WDIOC_SETTIMEOUT:
- {
- if (get_user(new_timeout, (int *)arg))
- return -EFAULT;
-
- pnx833x_wdt_timeout = new_timeout;
- PNX833X_REG(PNX833X_CONFIG +
- PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
- return put_user(new_timeout, (int *)arg);
- }
-
- case WDIOC_GETTIMEOUT:
- timeout = PNX833X_REG(PNX833X_CONFIG +
- PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
- return put_user(timeout, (int *)arg);
-
- case WDIOC_GETTIMELEFT:
- timeout_left = PNX833X_REG(PNX833X_CONFIG +
- PNX833X_CONFIG_CPU_WATCHDOG);
- return put_user(timeout_left, (int *)arg);
-
- }
+ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) =
+ t * WATCHDOG_COUNT_FREQUENCY;
+ wdd->timeout = t;
+ return 0;
}

-static int pnx833x_wdt_notify_sys(struct notifier_block *this,
- unsigned long code, void *unused)
+static unsigned int pnx833x_wdt_get_timeleft(struct watchdog_device *wdd)
{
- if (code == SYS_DOWN || code == SYS_HALT)
- pnx833x_wdt_stop(); /* Turn the WDT off */
+ unsigned int timeout = PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
+ unsigned int curval = PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG);

- return NOTIFY_DONE;
+ return (timeout - curval) / WATCHDOG_COUNT_FREQUENCY;
}

-static const struct file_operations pnx833x_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = pnx833x_wdt_write,
- .unlocked_ioctl = pnx833x_wdt_ioctl,
- .compat_ioctl = compat_ptr_ioctl,
- .open = pnx833x_wdt_open,
- .release = pnx833x_wdt_release,
+static const struct watchdog_info pnx833x_wdt_ident = {
+ .identity = "PNX833x Watchdog Timer",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE
};

-static struct miscdevice pnx833x_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &pnx833x_wdt_fops,
+static struct watchdog_ops pnx833x_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = pnx833x_wdt_start,
+ .stop = pnx833x_wdt_stop,
+ .ping = pnx833x_wdt_ping,
+ .set_timeout = pnx833x_wdt_set_timeout,
+ .get_timeleft = pnx833x_wdt_get_timeleft,
};

-static struct notifier_block pnx833x_wdt_notifier = {
- .notifier_call = pnx833x_wdt_notify_sys,
+struct pnx833x_wdt pnx833x_wdd = {
+ .wdd = {
+ .info = &pnx833x_wdt_ident,
+ .ops = &pnx833x_wdt_ops,
+ },
};

static int __init watchdog_init(void)
@@ -237,36 +129,29 @@ static int __init watchdog_init(void)
/* Lets check the reason for the reset.*/
cause = PNX833X_REG(PNX833X_RESET);
/*If bit 31 is set then watchdog was cause of reset.*/
- if (cause & 0x80000000) {
+ if (cause & 0x80000000)
pr_info("The system was previously reset due to the watchdog firing - please investigate...\n");
- }

- ret = register_reboot_notifier(&pnx833x_wdt_notifier);
- if (ret) {
- pr_err("cannot register reboot notifier (err=%d)\n", ret);
- return ret;
- }
+ pnx833x_wdd.wdd.max_timeout = U32_MAX / WATCHDOG_COUNT_FREQUENCY;
+ pnx833x_wdd.wdd.timeout = pnx833x_wdt_timeout;
+ if (pnx833x_wdd.wdd.timeout > pnx833x_wdd.wdd.max_timeout)
+ pnx833x_wdd.wdd.timeout = pnx833x_wdd.wdd.max_timeout;

- ret = misc_register(&pnx833x_wdt_miscdev);
+ watchdog_set_nowayout(&pnx833x_wdd.wdd, nowayout);
+ ret = watchdog_register_device(&pnx833x_wdd.wdd);
if (ret) {
- pr_err("cannot register miscdev on minor=%d (err=%d)\n",
- WATCHDOG_MINOR, ret);
- unregister_reboot_notifier(&pnx833x_wdt_notifier);
+ pr_err("Failed to register watchdog device");
return ret;
}

pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n");

- if (start_enabled)
- pnx833x_wdt_start();
-
return 0;
}

static void __exit watchdog_exit(void)
{
- misc_deregister(&pnx833x_wdt_miscdev);
- unregister_reboot_notifier(&pnx833x_wdt_notifier);
+ watchdog_unregister_device(&pnx833x_wdd.wdd);
}

module_init(watchdog_init);
--
2.26.2