* [RFC PATCH 3/5] watchdog: introduce retu_wdt driver
[not found] <1346189667-32330-1-git-send-email-aaro.koskinen@iki.fi>
@ 2012-08-28 21:34 ` Aaro Koskinen
2012-08-29 23:38 ` Tony Lindgren
0 siblings, 1 reply; 2+ messages in thread
From: Aaro Koskinen @ 2012-08-28 21:34 UTC (permalink / raw)
To: linux-omap; +Cc: linux-watchdog
Introduce Retu watchdog driver.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-watchdog@vger.kernel.org
---
drivers/watchdog/Kconfig | 12 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/retu_wdt.c | 191 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 204 insertions(+), 0 deletions(-)
create mode 100644 drivers/watchdog/retu_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 53d7571..0526c7a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -352,6 +352,18 @@ config IMX2_WDT
To compile this driver as a module, choose M here: the
module will be called imx2_wdt.
+config RETU_WATCHDOG
+ tristate "Retu watchdog"
+ depends on MFD_RETU
+ select WATCHDOG_CORE
+ help
+ Retu watchdog driver for Nokia Internet Tablets (700, N800,
+ N810). At least on N800 the watchdog cannot be disabled, so
+ this driver is essential and you should enable it.
+
+ To compile this driver as a module, choose M here: the
+ module will be called retu_wdt.
+
# AVR32 Architecture
config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 572b39b..d2f1c0c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
+obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/retu_wdt.c b/drivers/watchdog/retu_wdt.c
new file mode 100644
index 0000000..4a3ae00
--- /dev/null
+++ b/drivers/watchdog/retu_wdt.c
@@ -0,0 +1,191 @@
+/*
+ * Retu watchdog driver
+ *
+ * Copyright (C) 2004, 2005 Nokia Corporation
+ *
+ * Based on code written by Amit Kucheria and Michael Buesch. Rewritten
+ * to use Retu MFD driver and new watchdog core by Aaro Koskinen.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/retu.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+
+/* Watchdog timer values in seconds */
+#define RETU_WDT_MAX_TIMER 63
+
+/* Registers */
+#define RETU_REG_WATCHDOG 0x17
+
+struct retu_wdt_dev {
+ struct retu_dev *rdev;
+ struct device *dev;
+ struct delayed_work ping_work;
+};
+
+/*
+ * Since Retu watchdog cannot be disabled in hardware, we must kick it
+ * with a timer until userspace watchdog software takes over. If
+ * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
+ */
+static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
+{
+ retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
+ schedule_delayed_work(&wdev->ping_work,
+ round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
+}
+
+static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
+{
+ retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
+ cancel_delayed_work_sync(&wdev->ping_work);
+}
+
+static void retu_wdt_ping_work(struct work_struct *work)
+{
+ struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
+ struct retu_wdt_dev, ping_work);
+ retu_wdt_ping_enable(wdev);
+}
+
+static int retu_wdt_start(struct watchdog_device *wdog)
+{
+ struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ retu_wdt_ping_disable(wdev);
+
+ return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static int retu_wdt_stop(struct watchdog_device *wdog)
+{
+ struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ retu_wdt_ping_enable(wdev);
+
+ return 0;
+}
+
+static int retu_wdt_ping(struct watchdog_device *wdog)
+{
+ struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static int retu_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int timeout)
+{
+ struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ wdog->timeout = timeout;
+ return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
+}
+
+static const struct watchdog_info retu_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "Retu watchdog",
+};
+
+static const struct watchdog_ops retu_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = retu_wdt_start,
+ .stop = retu_wdt_stop,
+ .ping = retu_wdt_ping,
+ .set_timeout = retu_wdt_set_timeout,
+};
+
+static int __devinit retu_wdt_probe(struct platform_device *pdev)
+{
+ struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
+ bool nowayout = WATCHDOG_NOWAYOUT;
+ struct watchdog_device *retu_wdt;
+ struct retu_wdt_dev *wdev;
+ int ret;
+
+ retu_wdt = kzalloc(sizeof(*retu_wdt), GFP_KERNEL);
+ if (!retu_wdt)
+ return -ENOMEM;
+
+ wdev = kzalloc(sizeof(*wdev), GFP_KERNEL);
+ if (!wdev) {
+ ret = -ENOMEM;
+ goto error_mem;
+ }
+
+ retu_wdt->info = &retu_wdt_info;
+ retu_wdt->ops = &retu_wdt_ops;
+ retu_wdt->timeout = RETU_WDT_MAX_TIMER;
+ retu_wdt->min_timeout = 0;
+ retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;
+
+ watchdog_set_drvdata(retu_wdt, wdev);
+ watchdog_set_nowayout(retu_wdt, nowayout);
+
+ wdev->rdev = rdev;
+ wdev->dev = &pdev->dev;
+
+ INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work);
+
+ ret = watchdog_register_device(retu_wdt);
+ if (ret < 0)
+ goto error_reg;
+
+ if (nowayout)
+ retu_wdt_ping(retu_wdt);
+ else
+ retu_wdt_ping_enable(wdev);
+
+ platform_set_drvdata(pdev, retu_wdt);
+
+ return 0;
+
+error_reg:
+ kfree(wdev);
+error_mem:
+ kfree(retu_wdt);
+ return ret;
+}
+
+static int __devexit retu_wdt_remove(struct platform_device *pdev)
+{
+ struct watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ watchdog_unregister_device(wdog);
+ cancel_delayed_work_sync(&wdev->ping_work);
+ kfree(wdev);
+ kfree(wdog);
+
+ return 0;
+}
+
+static struct platform_driver retu_wdt_driver = {
+ .probe = retu_wdt_probe,
+ .remove = __devexit_p(retu_wdt_remove),
+ .driver = {
+ .name = "retu-wdt",
+ },
+};
+module_platform_driver(retu_wdt_driver);
+
+MODULE_ALIAS("platform:retu-wdt");
+MODULE_DESCRIPTION("Retu watchdog");
+MODULE_AUTHOR("Amit Kucheria");
+MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
+MODULE_LICENSE("GPL");
--
1.7.2.5
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