[PATCH 2/2] watchdog: as3722_wdt: support for AMS AS3722

Bibek Basu
2013-11-20T22:34:53Z

Add watchdog timer driver for as3722 device.
The timer can be start/stop and set timing through
watchdog subsystem callbacks.

Change-Id: I5e252fd762764afaa1598cd98fed91864dc23d8d
Signed-off-by: Bibek Basu <bbasu@nvidia.com>
---
drivers/watchdog/Kconfig | 9 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/as3722_wdt.c | 300 ++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/as3722.h | 1 +
4 files changed, 311 insertions(+)
create mode 100644 drivers/watchdog/as3722_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 74f29a2..15a5c08 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -53,6 +53,15 @@ comment "Watchdog Device Drivers"

# Architecture Independent

+config AS3722_WATCHDOG
+ tristate "AS3722 watchdog"
+ depends on MFD_AS3722
+ select WATCHDOG_CORE
+ help
+ Support for the watchdog in the AMS AS3722 PMIC. When
+ the watchdog triggers the system will be reset/Off based on
+ configuration.
+
config SOFT_WATCHDOG
tristate "Software watchdog"
select WATCHDOG_CORE
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 91bd95a..dab02f8 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -169,6 +169,7 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o
obj-$(CONFIG_XEN_WDT) += xen_wdt.o

# Architecture Independent
+obj-$(CONFIG_AS3722_WATCHDOG) += as3722_wdt.o
obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
diff --git a/drivers/watchdog/as3722_wdt.c b/drivers/watchdog/as3722_wdt.c
new file mode 100644
index 0000000..0ce0866
--- /dev/null
+++ b/drivers/watchdog/as3722_wdt.c
@@ -0,0 +1,300 @@
+/*
+ * as3722_wdt.c -- AS3722 Watchdog Timer.
+ *
+ * Watchdog timer for AS3722 PMIC.
+ *
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * Author: Bibek Basu <bbasu@nvidia.com>
+ * based on Palmas_wdt driver (c) Laxman Dewangan , 2013
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/as3722.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/watchdog.h>
+#include <linux/of.h>
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+struct as3722_wdt {
+ struct watchdog_device wdt_dev;
+ struct device *dev;
+ struct as3722 *as3722;
+ int timeout;
+ int irq;
+ int timer_initial_period;
+ int timer_mode;
+};
+
+static irqreturn_t as3722_wdt_irq(int irq, void *data)
+{
+ struct as3722_wdt *wdt = data;
+ int ret;
+
+ ret = as3722_update_bits(wdt->as3722,
+ AS3722_WATCHDOG_SOFTWARE_SIGNAL_REG,
+ AS3722_WATCHDOG_SW_SIG, AS3722_WATCHDOG_SW_SIG);
+ if (ret < 0)
+ dev_err(wdt->dev, "WATCHDOG kick failed: %d\n", ret);
+ dev_info(wdt->dev, "WDT interrupt occur\n");
+ return IRQ_HANDLED;
+}
+
+static int as3722_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct as3722_wdt *wdt = watchdog_get_drvdata(wdt_dev);
+ int ret;
+
+ ret = as3722_update_bits(wdt->as3722, AS3722_WATCHDOG_CONTROL_REG,
+ AS3722_WATCHDOG_ON, AS3722_WATCHDOG_ON);
+ if (ret < 0) {
+ dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int as3722_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct as3722_wdt *wdt = watchdog_get_drvdata(wdt_dev);
+ int ret;
+
+ ret = as3722_update_bits(wdt->as3722, AS3722_WATCHDOG_CONTROL_REG,
+ AS3722_WATCHDOG_ON, 0);
+ if (ret < 0) {
+ dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int as3722_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct as3722_wdt *wdt = watchdog_get_drvdata(wdt_dev);
+ int ret;
+ unsigned int val = timeout - 1;
+
+ ret = as3722_update_bits(wdt->as3722, AS3722_WATCHDOG_TIMER_REG,
+ AS3722_WATCHDOG_TIMER_MAX, val);
+ if (ret < 0) {
+ dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
+ return ret;
+ }
+ wdt->timeout = timeout;
+ return 0;
+}
+
+static const struct watchdog_info as3722_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .identity = "AS3722 Watchdog",
+};
+
+static const struct watchdog_ops as3722_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = as3722_wdt_start,
+ .stop = as3722_wdt_stop,
+ .set_timeout = as3722_wdt_set_timeout,
+};
+
+#ifdef CONFIG_OF
+static int as3722_parse_dt_wdt_data(
+ struct platform_device *pdev,
+ struct as3722_wdt *wdt)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const __be32 *prop;
+
+ prop = of_get_property(np, "ams,timer_initial_period", NULL);
+ if (prop)
+ wdt->timer_initial_period = be32_to_cpu(*prop);
+
+ prop = of_get_property(np, "ams,timer_mode", NULL);
+ if (prop)
+ wdt->timer_mode = be32_to_cpu(*prop);
+ else
+ wdt->timer_mode = -1;
+ return 0;
+}
+#else
+static inline int as3722_parse_dt_wdt_data(
+ struct platform_device *pdev,
+ struct as3722_wdt *wdt)
+{
+ return 0;
+}
+#endif
+
+static int as3722_wdt_probe(struct platform_device *pdev)
+{
+ struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
+ struct as3722_wdt *wdt;
+ struct watchdog_device *wdt_dev;
+ int ret;
+
+ wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ as3722_parse_dt_wdt_data(pdev, wdt);
+ wdt->dev = &pdev->dev;
+ wdt->as3722 = as3722;
+ wdt->irq = as3722_irq_get_virq(wdt->as3722, AS3722_IRQ_WATCHDOG);
+ wdt_dev = &wdt->wdt_dev;
+
+ wdt_dev->info = &as3722_wdt_info;
+ wdt_dev->ops = &as3722_wdt_ops;
+ wdt_dev->timeout = 128;
+ wdt_dev->min_timeout = 8;
+ wdt_dev->max_timeout = 128;
+ watchdog_set_nowayout(wdt_dev, nowayout);
+ watchdog_set_drvdata(wdt_dev, wdt);
+ platform_set_drvdata(pdev, wdt);
+
+ ret = request_threaded_irq(wdt->irq, NULL, as3722_wdt_irq,
+ IRQF_ONESHOT | IRQF_EARLY_RESUME,
+ dev_name(&pdev->dev), wdt);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
+ wdt->irq, ret);
+ return ret;
+ }
+
+ ret = watchdog_register_device(wdt_dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
+ return ret;
+ }
+
+ /* set mode */
+ if (wdt->timer_mode >= 0) {
+ ret = as3722_update_bits(wdt->as3722,
+ AS3722_WATCHDOG_CONTROL_REG,
+ AS3722_WATCHDOG_MODE_MASK, wdt->timer_mode);
+ if (ret < 0) {
+ dev_err(wdt->dev, "WATCHDOG update mode failed: %d\n",
+ ret);
+ goto scrub;
+ }
+ }
+
+ /* configure timer */
+ if (wdt->timer_initial_period > 0) {
+ ret = as3722_wdt_set_timeout(wdt_dev,
+ wdt->timer_initial_period);
+ if (ret < 0) {
+ dev_err(wdt->dev, "wdt set timeout failed: %d\n", ret);
+ goto scrub;
+ }
+ ret = as3722_wdt_start(wdt_dev);
+ if (ret < 0) {
+ dev_err(wdt->dev,
+ "wdt start failed: %d\n", ret);
+ goto scrub;
+ }
+ }
+
+ device_set_wakeup_capable(&pdev->dev, 1);
+ return 0;
+scrub:
+ free_irq(wdt->irq, wdt);
+ watchdog_unregister_device(&wdt->wdt_dev);
+ return ret;
+}
+
+static int as3722_wdt_remove(struct platform_device *pdev)
+{
+ struct as3722_wdt *wdt = platform_get_drvdata(pdev);
+
+ as3722_wdt_stop(&wdt->wdt_dev);
+ watchdog_unregister_device(&wdt->wdt_dev);
+ free_irq(wdt->irq, wdt);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int as3722_wdt_suspend(struct device *dev)
+{
+ struct as3722_wdt *wdt = dev_get_drvdata(dev);
+ int ret;
+
+ if (device_may_wakeup(dev)) {
+ enable_irq_wake(wdt->irq);
+ } else if (wdt->timeout > 0) {
+ ret = as3722_wdt_stop(&wdt->wdt_dev);
+ if (ret < 0)
+ dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
+ }
+ return 0;
+}
+
+static int as3722_wdt_resume(struct device *dev)
+{
+ struct as3722_wdt *wdt = dev_get_drvdata(dev);
+ int ret;
+
+ if (device_may_wakeup(dev)) {
+ disable_irq_wake(wdt->irq);
+ } else if (wdt->timeout > 0) {
+ ret = as3722_wdt_start(&wdt->wdt_dev);
+ if (ret < 0)
+ dev_err(wdt->dev, "wdt start failed: %d\n", ret);
+ }
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops as3722_wdt_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(as3722_wdt_suspend, as3722_wdt_resume)
+};
+
+static const struct of_device_id as3722_wdt_of_match[] = {
+ { .compatible = "ams,as3722-wdt", },
+ { /* end */ }
+};
+
+static struct platform_driver as3722_wdt_driver = {
+ .driver = {
+ .name = "as3722-wdt",
+ .owner = THIS_MODULE,
+ .pm = &as3722_wdt_pm_ops,
+ .of_match_table = as3722_wdt_of_match,
+ },
+ .probe = as3722_wdt_probe,
+ .remove = as3722_wdt_remove,
+};
+
+static int __init as3722_wdt_init(void)
+{
+ return platform_driver_register(&as3722_wdt_driver);
+}
+subsys_initcall(as3722_wdt_init);
+
+static void __exit as3722_wdt_exit(void)
+{
+ platform_driver_unregister(&as3722_wdt_driver);
+}
+module_exit(as3722_wdt_exit);
+
+MODULE_ALIAS("platform:as3722-wdt");
+MODULE_DESCRIPTION("AMS AS3722 watchdog timer driver");
+MODULE_AUTHOR("Bibek Basu <bbasu@nvidia.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/as3722.h b/include/linux/mfd/as3722.h
index 16bf8a0..9290fd6 100644
--- a/include/linux/mfd/as3722.h
+++ b/include/linux/mfd/as3722.h
@@ -336,6 +336,7 @@
#define AS3722_WATCHDOG_TIMER_MAX 0x7F
#define AS3722_WATCHDOG_ON BIT(0)
#define AS3722_WATCHDOG_SW_SIG BIT(0)
+#define AS3722_WATCHDOG_MODE_MASK 0x06

#define AS3722_EXT_CONTROL_ENABLE1 0x1
#define AS3722_EXT_CONTROL_ENABLE2 0x2
--
1.8.1.5