Signed-off-by: Richard Vidal-Dorsch <richard.dor...@gmail.com>
---
 drivers/watchdog/Kconfig        |  11 ++
 drivers/watchdog/Makefile       |   1 +
 drivers/watchdog/imanager_wdt.c | 303 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 315 insertions(+)
 create mode 100644 drivers/watchdog/imanager_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index fdd3228..d6859da 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -912,6 +912,17 @@ config WAFER_WDT
          To compile this driver as a module, choose M here: the
          module will be called wafer5823wdt.
 
+config IMANAGER_WDT
+       tristate "Advantech iManager Watchdog"
+       depends on MFD_IMANAGER
+       select WATCHDOG_CORE
+       help
+         Support for Advantech iManager watchdog on some Advantech
+         SOM, MIO, AIMB, and PCM modules/boards.
+
+         This driver can also be built as a module.  If so, the module
+         will be called imanager_wdt.
+
 config I6300ESB_WDT
        tristate "Intel 6300ESB Timer/Watchdog"
        depends on PCI
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index caa9f4a..eb7fccf 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -117,6 +117,7 @@ endif
 obj-$(CONFIG_IT8712F_WDT) += it8712f_wdt.o
 obj-$(CONFIG_IT87_WDT) += it87_wdt.o
 obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
+obj-$(CONFIG_IMANAGER_WDT) += imanager_wdt.o
 obj-$(CONFIG_KEMPLD_WDT) += kempld_wdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
diff --git a/drivers/watchdog/imanager_wdt.c b/drivers/watchdog/imanager_wdt.c
new file mode 100644
index 0000000..53b409e
--- /dev/null
+++ b/drivers/watchdog/imanager_wdt.c
@@ -0,0 +1,303 @@
+/*
+ * Advantech iManager Watchdog driver
+ *
+ * Copyright (C) 2016 Advantech Co., Ltd.
+ * Author: Richard Vidal-Dorsch <richard.dor...@advantech.com>
+ *
+ * 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;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/byteorder/generic.h>
+#include <linux/device.h>
+#include <linux/mfd/imanager.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define WDT_DEFAULT_TIMEOUT    30 /* seconds */
+#define WDT_FREQ               10 /* Hz */
+
+struct imanager_wdt_data {
+       struct imanager_device_data *imgr;
+       struct watchdog_device wdt;
+       ulong last_updated;
+       uint timeout;
+};
+
+static uint timeout = WDT_DEFAULT_TIMEOUT;
+module_param(timeout, uint, 0444);
+MODULE_PARM_DESC(timeout,
+                "Watchdog timeout in seconds. 1 <= timeout <= 65534, default="
+                __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ".");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0444);
+MODULE_PARM_DESC(nowayout,
+                "Watchdog cannot be stopped once started (default="
+                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+enum wdt_ctrl {
+       START = 1, STOP, RESET, GET_TIMEOUT, SET_TIMEOUT, STOPBOOT = 8
+};
+
+enum imanager_wdt_event {
+       WDT_EVT_NONE,
+       WDT_EVT_DELAY,
+       WDT_EVT_PWRBTN,
+       WDT_EVT_NMI,
+       WDT_EVT_RESET,
+       WDT_EVT_WDPIN,
+       WDT_EVT_SCI,
+};
+
+struct event_delay {
+       u16     delay,
+               pwrbtn,
+               nmi,
+               reset,
+               wdpin,
+               sci,
+               dummy;
+} __attribute__((__packed__));
+
+static int imanager_wdt_ctrl(struct imanager_ec_data *ec, int ctrl,
+                            int event_type, uint timeout)
+{
+       struct imanager_ec_message msg = {
+               IMANAGER_MSG_SIMPLE(0, 0, ctrl, NULL)
+       };
+       u8 *fevent = &msg.u.data[0];
+       struct event_delay *event = (struct event_delay *)&msg.u.data[1];
+       int val;
+
+       if (ctrl == SET_TIMEOUT) {
+               memset(event, 0xff, sizeof(*event));
+               msg.wlen = sizeof(*event);
+               *fevent = 0;
+               val = (!timeout) ? 0xffff : cpu_to_be16(timeout * WDT_FREQ);
+
+               switch (event_type) {
+               case WDT_EVT_DELAY:
+                       event->delay = val;
+                       break;
+               case WDT_EVT_PWRBTN:
+                       event->pwrbtn = val;
+                       break;
+               case WDT_EVT_NMI:
+                       event->nmi = val;
+                       break;
+               case WDT_EVT_RESET:
+                       event->reset = val;
+                       break;
+               case WDT_EVT_WDPIN:
+                       event->wdpin = val;
+                       break;
+               case WDT_EVT_SCI:
+                       event->sci = val;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       return imanager_write(ec, EC_CMD_WDT_CTRL, &msg);
+}
+
+static inline int imanager_wdt_disable_all(struct imanager_wdt_data *data)
+{
+       struct imanager_ec_data *ec = &data->imgr->ec;
+
+       return (imanager_wdt_ctrl(ec, STOP, WDT_EVT_NONE, 0) ||
+               imanager_wdt_ctrl(ec, STOPBOOT, WDT_EVT_NONE, 0));
+}
+
+static int imanager_wdt_set(struct imanager_wdt_data *data, uint timeout)
+{
+       struct imanager_ec_data *ec = &data->imgr->ec;
+       int ret;
+
+       if (time_before(jiffies, data->last_updated + HZ + HZ / 2))
+               return 0;
+
+       if (data->timeout == timeout)
+               return 0;
+
+       ret = imanager_wdt_ctrl(ec, SET_TIMEOUT, WDT_EVT_PWRBTN, timeout);
+       if (ret < 0)
+               return ret;
+
+       data->timeout = timeout;
+       data->last_updated = jiffies;
+
+       return 0;
+}
+
+static int imanager_wdt_set_timeout(struct watchdog_device *wdt, uint timeout)
+{
+       struct imanager_wdt_data *data = watchdog_get_drvdata(wdt);
+       struct imanager_device_data *imgr = data->imgr;
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_wdt_set(data, timeout);
+       mutex_unlock(&imgr->lock);
+
+       return ret;
+}
+
+static uint imanager_wdt_get_timeleft(struct watchdog_device *wdt)
+{
+       struct imanager_wdt_data *data = watchdog_get_drvdata(wdt);
+       uint timeleft = 0;
+       ulong time_diff = ((jiffies - data->last_updated) / HZ);
+
+       if (data->last_updated && (data->timeout > time_diff))
+               timeleft = data->timeout - time_diff;
+
+       return timeleft;
+}
+
+static int imanager_wdt_start(struct watchdog_device *wdt)
+{
+       struct imanager_wdt_data *data = watchdog_get_drvdata(wdt);
+       struct imanager_device_data *imgr = data->imgr;
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_wdt_ctrl(&imgr->ec, START, WDT_EVT_NONE, 0);
+       data->last_updated = jiffies;
+       mutex_unlock(&imgr->lock);
+
+       return ret;
+}
+
+static int imanager_wdt_stop(struct watchdog_device *wdt)
+{
+       struct imanager_wdt_data *data = watchdog_get_drvdata(wdt);
+       struct imanager_device_data *imgr = data->imgr;
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_wdt_ctrl(&imgr->ec, STOP, WDT_EVT_NONE, 0);
+       data->last_updated = 0;
+       mutex_unlock(&imgr->lock);
+
+       return ret;
+}
+
+static int imanager_wdt_ping(struct watchdog_device *wdt)
+{
+       struct imanager_wdt_data *data = watchdog_get_drvdata(wdt);
+       struct imanager_device_data *imgr = data->imgr;
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_wdt_ctrl(&imgr->ec, RESET, WDT_EVT_NONE, 0);
+       data->last_updated = jiffies;
+       mutex_unlock(&imgr->lock);
+
+       return ret;
+}
+
+static const struct watchdog_info imanager_wdt_info = {
+       .options                = WDIOF_SETTIMEOUT |
+                                 WDIOF_KEEPALIVEPING |
+                                 WDIOF_MAGICCLOSE,
+       .firmware_version       = 0,
+       .identity               = "imanager-wdt",
+};
+
+static const struct watchdog_ops imanager_wdt_ops = {
+       .owner          = THIS_MODULE,
+       .start          = imanager_wdt_start,
+       .stop           = imanager_wdt_stop,
+       .ping           = imanager_wdt_ping,
+       .set_timeout    = imanager_wdt_set_timeout,
+       .get_timeleft   = imanager_wdt_get_timeleft,
+};
+
+static int imanager_wdt_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct imanager_device_data *imgr = dev_get_drvdata(dev->parent);
+       struct imanager_wdt_data *data;
+       struct watchdog_device *wdt_dev;
+       int ret;
+
+       data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->imgr = imgr;
+
+       wdt_dev = &data->wdt;
+       wdt_dev->info           = &imanager_wdt_info;
+       wdt_dev->ops            = &imanager_wdt_ops;
+       wdt_dev->timeout        = WDT_DEFAULT_TIMEOUT;
+       wdt_dev->min_timeout    = 1;
+       wdt_dev->max_timeout    = 0xfffe;
+
+       watchdog_set_nowayout(wdt_dev, nowayout);
+       watchdog_set_drvdata(wdt_dev, data);
+
+       ret = watchdog_register_device(wdt_dev);
+       if (ret) {
+               dev_err(dev, "Could not register watchdog device\n");
+               return ret;
+       }
+
+       platform_set_drvdata(pdev, data);
+
+       imanager_wdt_disable_all(data);
+       imanager_wdt_set_timeout(wdt_dev, timeout);
+
+       dev_info(dev, "Driver loaded (timeout=%d seconds)\n", timeout);
+
+       return 0;
+}
+
+static int imanager_wdt_remove(struct platform_device *pdev)
+{
+       struct imanager_wdt_data *data = platform_get_drvdata(pdev);
+
+       if (!nowayout)
+               imanager_wdt_disable_all(data);
+
+       watchdog_unregister_device(&data->wdt);
+       platform_set_drvdata(pdev, NULL);
+
+       return 0;
+}
+
+static void imanager_wdt_shutdown(struct platform_device *pdev)
+{
+       struct imanager_device_data *imgr = dev_get_drvdata(pdev->dev.parent);
+
+       mutex_lock(&imgr->lock);
+       imanager_wdt_ctrl(&imgr->ec, STOP, WDT_EVT_NONE, 0);
+       mutex_unlock(&imgr->lock);
+}
+
+static struct platform_driver imanager_wdt_driver = {
+       .driver = {
+               .name   = "imanager-wdt",
+       },
+       .probe          = imanager_wdt_probe,
+       .remove         = imanager_wdt_remove,
+       .shutdown       = imanager_wdt_shutdown,
+};
+
+module_platform_driver(imanager_wdt_driver);
+
+MODULE_DESCRIPTION("Advantech iManager Watchdog Driver");
+MODULE_AUTHOR("Richard Vidal-Dorsch <richard.dorsch at advantech.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imanager-wdt");
-- 
2.10.1

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