From: Johannes Thumshirn <johannes.thumsh...@men.de>
This patch adds the driver for the watchdog devices found on MEN Mikro
Elektronik A21 VMEbus CPU Carrier Boards. It has DT-support and uses the
watchdog framework.
Signed-off-by: Johannes Thumshirn <johannes.thumsh...@men.de>
---
MAINTAINERS | 6 +
drivers/watchdog/Kconfig | 8 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mena21_wdt.c | 351 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 366 insertions(+)
create mode 100644 drivers/watchdog/mena21_wdt.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 3d7782b..3e5b3f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5291,6 +5291,12 @@ F: drivers/mtd/
F: include/linux/mtd/
F: include/uapi/mtd/
+MEN A21 WATCHDOG DRIVER
+M: Johannes Thumshirn <johannes.thumsh...@men.de>
+L: linux-watch...@vger.kernel.org
+S: Supported
+F: drivers/watchdog/mena21_wdt.c
+
METAG ARCHITECTURE
M: James Hogan <james.ho...@imgtec.com>
S: Supported
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index e89fc31..192b84d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1172,6 +1172,14 @@ config BOOKE_WDT_DEFAULT_TIMEOUT
The value can be overridden by the wdt_period command-line parameter.
+config MEN_A21_WDT
+ tristate "MEN A21 VME CPU Carrier Board Watchdog Timer"
+ select WATCHDOG_CORE
+ help
+ Watchdog driver for MEN A21 VMEbus CPU Carrier Boards.
+
+ If unsure select N here.
+
# PPC64 Architecture
config WATCHDOG_RTAS
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index a300b94..bffdcb1 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -143,6 +143,7 @@ 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
+obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o
# PPC64 Architecture
obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
diff --git a/drivers/watchdog/mena21_wdt.c b/drivers/watchdog/mena21_wdt.c
new file mode 100644
index 0000000..d534f81
--- /dev/null
+++ b/drivers/watchdog/mena21_wdt.c
@@ -0,0 +1,351 @@
+/*
+ * Watchdog driver for the A21 VME CPU Boards
+ *
+ * Copyright (C) 2013 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ * 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
+ */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/uaccess.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/bitops.h>
+
+static char *reset_causes[] = {
+ "Power On Reset",
+ "CPU Reset Request",
+ "Push Button",
+ "FPGA Reset Request",
+ "Watchdog",
+ "Local Power Bad",
+ "Invalid",
+ "BDI",
+};
+
+#define GPIO_WD_ENAB 169
+#define GPIO_WD_FAST 170
+#define GPIO_WD_TRIG 171
+
+#define GPIO_RST_CAUSE_BASE 166
+
+struct a21_wdt_drv {
+ struct watchdog_device wdt;
+ struct mutex lock;
+ bool open;
+};
+
+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) ")");
+
+static ssize_t rebootcause_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ unsigned int reset = 0;
+ int i;
+
+ for (i = 0; i < 3; i++)
+ reset |= !!gpio_get_value(GPIO_RST_CAUSE_BASE + i);
+
+ if (reset >= 8)
+ return -EIO;
+
+ return sprintf(buf, "%s\n", reset_causes[reset]);
+}
+static DEVICE_ATTR(rebootcause, S_IRUGO, rebootcause_show, NULL);
+
+static ssize_t active_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", !!gpio_get_value(GPIO_WD_ENAB));
+}
+static DEVICE_ATTR(active, S_IRUGO, active_show, NULL);
+
+static ssize_t allow_disable_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", !nowayout);
+}
+static DEVICE_ATTR(allow_disable, S_IRUGO, allow_disable_show, NULL);
+
+static ssize_t fastmode_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", !!gpio_get_value(GPIO_WD_FAST));
+}
+static DEVICE_ATTR(fastmode, S_IRUGO, fastmode_show, NULL);
+
+static int a21_wdt_create_files(struct device *dev)
+{
+ int ret;
+
+ ret = device_create_file(dev, &dev_attr_rebootcause);
+ if (ret)
+ return ret;
+ ret = device_create_file(dev, &dev_attr_active);
+ if (ret)
+ return ret;
+ ret = device_create_file(dev, &dev_attr_allow_disable);
+ if (ret)
+ return ret;
+ ret = device_create_file(dev, &dev_attr_fastmode);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void a21_wdt_remove_files(struct device *dev)
+{
+ device_remove_file(dev, &dev_attr_rebootcause);
+ device_remove_file(dev, &dev_attr_active);
+ device_remove_file(dev, &dev_attr_allow_disable);
+ device_remove_file(dev, &dev_attr_fastmode);
+}
+
+static int a21_wdt_start(struct watchdog_device *wdt)
+{
+ struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
+
+ mutex_lock(&drv->lock);
+
+ drv->open = true;
+ gpio_set_value(GPIO_WD_ENAB, 1);
+
+ mutex_unlock(&drv->lock);
+
+ return 0;
+}
+
+static int a21_wdt_stop(struct watchdog_device *wdt)
+{
+ struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
+
+ /* We don't stop if WDOG_NO_WAY_OUT is set */
+ if (test_bit(WDOG_NO_WAY_OUT, &wdt->status))
+ return -EINVAL;
+
+ mutex_lock(&drv->lock);
+
+ gpio_set_value(GPIO_WD_ENAB, 0);
+ drv->open = false;
+
+ mutex_unlock(&drv->lock);
+
+ return 0;
+}
+
+static int a21_wdt_ping(struct watchdog_device *wdt)
+{
+ struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
+
+ mutex_lock(&drv->lock);
+
+ gpio_set_value(GPIO_WD_TRIG, 0);
+ msleep(400);
+ gpio_set_value(GPIO_WD_TRIG, 1);
+
+ mutex_unlock(&drv->lock);
+
+ return 0;
+}
+
+static int a21_wdt_set_timeout(struct watchdog_device *wdt,
+ unsigned int timeout)
+{
+ struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
+
+ if (timeout != 1 || timeout != 30) {
+ pr_err("Only 1 and 30 allowed as timeout\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&drv->lock);
+
+ if (timeout == 30)
+ gpio_set_value(GPIO_WD_FAST, 1);
+ else
+ gpio_set_value(GPIO_WD_FAST, 0);
+
+ wdt->timeout = timeout;
+
+ mutex_unlock(&drv->lock);
+
+ return 0;
+}
+
+static long a21_wdt_ioctl(struct watchdog_device *wdt, unsigned int cmd,
+ unsigned long arg)
+{
+ unsigned int timeout;
+ int ret;
+ int __user *argp = (void __user *) arg;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp,
+ wdt->info, sizeof(struct watchdog_info));
+ case WDIOC_KEEPALIVE:
+ return a21_wdt_ping(wdt);
+ case WDIOC_SETTIMEOUT:
+ ret = get_user(timeout, argp);
+ if (ret)
+ return ret;
+ a21_wdt_set_timeout(wdt, timeout);
+ /* Fallthrough */
+ case WDIOC_GETTIMEOUT:
+ return put_user(wdt->timeout, argp);
+ case WDIOC_SETOPTIONS: {
+ int options;
+
+ ret = get_user(options, argp);
+ if (ret)
+ return ret;
+ if (options & WDIOS_DISABLECARD)
+ a21_wdt_stop(wdt);
+ if (options & WDIOS_ENABLECARD)
+ a21_wdt_start(wdt);
+ break;
+ }
+ default:
+ pr_err("IOCTL 0x%x not understood\n", cmd);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int a21_wdt_notify_sys(struct notifier_block *notify, unsigned long
code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ gpio_set_value(GPIO_WD_ENAB, 0);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block a21_wdt_notifier = {
+ .notifier_call = a21_wdt_notify_sys,
+};
+
+static const struct watchdog_info a21_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "MEN A21 Watchdog",
+};
+
+static const struct watchdog_ops a21_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = a21_wdt_start,
+ .stop = a21_wdt_stop,
+ .ping = a21_wdt_ping,
+ .set_timeout = a21_wdt_set_timeout,
+ .ioctl = a21_wdt_ioctl,
+};
+
+static struct watchdog_device a21_wdt = {
+ .info = &a21_wdt_info,
+ .ops = &a21_wdt_ops,
+ .min_timeout = 1,
+ .max_timeout = 30,
+};
+
+static int a21_wdt_probe(struct platform_device *pdev)
+{
+ struct a21_wdt_drv *drv;
+ int ret;
+
+ pr_info("MEN A21 watchdog timer driver enabled\n");
+
+ drv = devm_kzalloc(&pdev->dev, sizeof(struct a21_wdt_drv), GFP_KERNEL);
+ if (!drv) {
+ dev_err(&pdev->dev,
+ "Unable to allocate memory for watchdog device\n");
+ return -ENOMEM;
+ }
+
+ mutex_init(&drv->lock);
+ watchdog_set_nowayout(&a21_wdt, nowayout);
+ watchdog_set_drvdata(&a21_wdt, drv);
+
+ ret = watchdog_register_device(&a21_wdt);
+ if (ret) {
+ pr_err("Cannot register watchdog device\n");
+ goto err_register_wd;
+ }
+
+ ret = register_reboot_notifier(&a21_wdt_notifier);
+ if (ret) {
+ pr_err("Cannot register reboot notifier\n");
+ goto err_register_notif;
+ }
+
+ ret = a21_wdt_create_files(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot create sysfs entries\n");
+ goto err_create_sysfs;
+ }
+
+ dev_set_drvdata(&pdev->dev, drv);
+
+ return 0;
+
+err_create_sysfs:
+ unregister_reboot_notifier(&a21_wdt_notifier);
+err_register_notif:
+ watchdog_unregister_device(&drv->wdt);
+err_register_wd:
+ mutex_destroy(&drv->lock);
+ devm_kfree(&pdev->dev, drv);
+
+ return ret;
+}
+
+static int a21_wdt_remove(struct platform_device *pdev)
+{
+ struct a21_wdt_drv *drv = dev_get_drvdata(&pdev->dev);
+
+ pr_warn("Unregistering A21 watchdog driver, board may reboot\n");
+
+ a21_wdt_remove_files(&pdev->dev);
+
+ watchdog_unregister_device(&drv->wdt);
+ unregister_reboot_notifier(&a21_wdt_notifier);
+
+ mutex_destroy(&drv->lock);
+ devm_kfree(&pdev->dev, drv);
+
+ return 0;
+}
+
+static const struct of_device_id a21_wdt_ids[] = {
+ { .compatible = "men,a021-wdt" },
+ { },
+};
+
+static struct platform_driver a21_wdt_driver = {
+ .probe = a21_wdt_probe,
+ .remove = a21_wdt_remove,
+ .driver = {
+ .name = "a21-watchdog",
+ .of_match_table = a21_wdt_ids,
+ },
+};
+
+module_platform_driver(a21_wdt_driver);
+
+MODULE_AUTHOR("MEN Mikro Elektronik");
+MODULE_DESCRIPTION("MEN A21 Watchdog");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:a21-watchdog");
--
1.7.9.5
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