[RESEND PATCH] watchdog: ni7018_wdt: Add NIC7018 watchdog driver

[Hui Chun Ong <hui.chun.ong@ni.com>]

Add support for the watchdog timer on PXI Embedded Controller.

Signed-off-by: Hui Chun Ong <hui.chun.ong@ni.com>
---
 Documentation/watchdog/watchdog-parameters.txt |   5 +
 drivers/watchdog/Kconfig                       |  11 +
 drivers/watchdog/Makefile                      |   1 +
 drivers/watchdog/ni7018_wdt.c                  | 506 +++++++++++++++++++++++++
 4 files changed, 523 insertions(+)
 create mode 100644 drivers/watchdog/ni7018_wdt.c

diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index a8d3642..25dbfa2 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -204,6 +204,11 @@ mv64x60_wdt:
 nowayout: Watchdog cannot be stopped once started
 	(default=kernel config parameter)
 -------------------------------------------------
+ni7018_wdt:
+timeout: Initial watchdog timeout in seconds (0<timeout<464, default=80)
+nowayout: Watchdog cannot be stopped once started
+	(default=kernel config parameter)
+-------------------------------------------------
 ni903x_wdt:
 timeout: Initial watchdog timeout in seconds (0<timeout<516, default=60)
 nowayout: Watchdog cannot be stopped once started
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index fdd3228..6d185af 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1314,6 +1314,17 @@ config INTEL_MEI_WDT
 	  To compile this driver as a module, choose M here:
 	  the module will be called mei_wdt.
 
+config NI7018_WDT
+	tristate "NI 7018 Watchdog"
+	depends on X86 && ACPI
+	select WATCHDOG_CORE
+	---help---
+	  This is the device driver for National Instruments NIC7018 watchdog
+	  timer.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ni7018_wdt.
+
 config NI903X_WDT
 	tristate "NI 903x/913x Watchdog"
 	depends on X86 && ACPI
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index caa9f4a..4605cd2 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -139,6 +139,7 @@ obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
 obj-$(CONFIG_INTEL_MID_WATCHDOG) += intel-mid_wdt.o
 obj-$(CONFIG_INTEL_MEI_WDT) += mei_wdt.o
 obj-$(CONFIG_NI903X_WDT) += ni903x_wdt.o
+obj-$(CONFIG_NI7018_WDT) += ni7018_wdt.o
 
 # M32R Architecture
 
diff --git a/drivers/watchdog/ni7018_wdt.c b/drivers/watchdog/ni7018_wdt.c
new file mode 100644
index 0000000..7690314
--- /dev/null
+++ b/drivers/watchdog/ni7018_wdt.c
@@ -0,0 +1,506 @@
+/*
+ * Copyright (C) 2016 National Instruments Corp.
+ *
+ * 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.
+ *
+ * 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/acpi.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/watchdog.h>
+
+#define LOCK		0xA5
+#define UNLOCK		0x5A
+
+#define WDT_CTRL_RESET_EN		BIT(7)
+#define WDT_CTRL_TRIG_POLARITY		BIT(4)
+#define WDT_CTRL_TRIG			0x0F
+
+#define WDT_RELOAD_PORT_EN		BIT(7)
+#define WDT_RELOAD_TRIG_POLARITY	BIT(6)
+#define WDT_RELOAD_TRIG			0x0F
+#define WDT_MIN_TRIG_NUM		0
+#define WDT_MAX_TRIG_NUM		8
+
+#define WDT_CTRL		1
+#define WDT_RELOAD_CTRL		2
+#define WDT_PRESET_PRESCALE	4
+#define WDT_REG_LOCK		5
+#define WDT_COUNT		6
+#define WDT_RELOAD_PORT		7
+
+#define WDT_IO_SIZE		8
+
+#define WDT_MIN_TIMEOUT		1
+#define WDT_MAX_TIMEOUT		464
+#define WDT_DEFAULT_TIMEOUT	80
+
+#define WDT_MAX_COUNTER		15
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+		 "Watchdog timeout in seconds. (default="
+		 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, S_IRUGO);
+MODULE_PARM_DESC(nowayout,
+		 "Watchdog cannot be stopped once started. (default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct ni7018_wdt {
+	struct device *dev;
+	u16 io_base;
+	u32 period_ms;
+	struct mutex lock;
+	struct watchdog_device wdd;
+};
+
+struct ni7018_config {
+	u32 period_ms;
+	u8 divider;
+};
+
+static const struct ni7018_config ni7018_configs[] = {
+	{   125, 3 },
+	{  2000, 4 },
+	{ 32000, 5 },
+};
+
+static inline u32 ni7018_timeout_ms(u32 period_ms, u8 counter)
+{
+	return period_ms * counter - period_ms / 2;
+}
+
+static const struct ni7018_config *ni7018_get_config(u32 timeout_ms,
+						     u8 *counter)
+{
+	u32 delta, i, best_delta = U32_MAX;
+	const struct ni7018_config *config, *best_config = NULL;
+	u8 count;
+
+	for (i = 0; i < ARRAY_SIZE(ni7018_configs); i++) {
+		config = &ni7018_configs[i];
+
+		count = DIV_ROUND_UP(timeout_ms + config->period_ms / 2,
+				     config->period_ms);
+
+		if (count > WDT_MAX_COUNTER)
+			continue;
+
+		delta = ni7018_timeout_ms(config->period_ms, count) -
+			timeout_ms;
+
+		if (delta < best_delta) {
+			best_delta = delta;
+			best_config = config;
+			*counter = count;
+		}
+	}
+	return best_config;
+}
+
+static int ni7018_set_timeout(struct watchdog_device *wdd,
+			      unsigned int timeout)
+{
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	const struct ni7018_config *config;
+	u8 counter;
+
+	config = ni7018_get_config(timeout * 1000, &counter);
+	if (!config)
+		return -EINVAL;
+
+	mutex_lock(&wdt->lock);
+
+	outb(counter << 4 | config->divider,
+	     wdt->io_base + WDT_PRESET_PRESCALE);
+
+	wdd->timeout = ni7018_timeout_ms(config->period_ms, counter) / 1000;
+	wdt->period_ms = config->period_ms;
+
+	mutex_unlock(&wdt->lock);
+	return 0;
+}
+
+static int ni7018_start(struct watchdog_device *wdd)
+{
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	u8 control;
+
+	ni7018_set_timeout(wdd, wdd->timeout);
+
+	mutex_lock(&wdt->lock);
+
+	control = inb(wdt->io_base + WDT_RELOAD_CTRL);
+	outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);
+
+	outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+	control = inb(wdt->io_base + WDT_CTRL);
+	outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);
+
+	mutex_unlock(&wdt->lock);
+	return 0;
+}
+
+static int ni7018_stop(struct watchdog_device *wdd)
+{
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	mutex_lock(&wdt->lock);
+
+	outb(0, wdt->io_base + WDT_CTRL);
+	outb(0, wdt->io_base + WDT_RELOAD_CTRL);
+	outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
+
+	mutex_unlock(&wdt->lock);
+	return 0;
+}
+
+static int ni7018_ping(struct watchdog_device *wdd)
+{
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	mutex_lock(&wdt->lock);
+
+	outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+	mutex_unlock(&wdt->lock);
+	return 0;
+}
+
+static unsigned int ni7018_get_timeleft(struct watchdog_device *wdd)
+{
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	u8 count;
+
+	mutex_lock(&wdt->lock);
+
+	count = inb(wdt->io_base + WDT_COUNT) & 0xF;
+
+	mutex_unlock(&wdt->lock);
+
+	if (!count)
+		return 0;
+
+	return ni7018_timeout_ms(wdt->period_ms, count) / 1000;
+}
+
+static acpi_status
+ni7018_resources(struct acpi_resource *res, void *data)
+{
+	struct ni7018_wdt *wdt = data;
+	u16 io_size;
+
+	switch (res->type) {
+	case ACPI_RESOURCE_TYPE_IO:
+		if (wdt->io_base != 0) {
+			dev_err(wdt->dev, "too many IO resources\n");
+			return AE_ERROR;
+		}
+
+		wdt->io_base = res->data.io.minimum;
+		io_size = res->data.io.address_length;
+
+		if (io_size < WDT_IO_SIZE) {
+			dev_err(wdt->dev, "memory region too small\n");
+			return AE_ERROR;
+		}
+
+		if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
+					 KBUILD_MODNAME)) {
+			dev_err(wdt->dev, "failed to get memory region\n");
+			return AE_ERROR;
+		}
+
+		return AE_OK;
+
+	default:
+		/* Ignore unsupported resources */
+		return AE_OK;
+	}
+}
+
+static const struct watchdog_info ni7018_wdd_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "NI 7018 Watchdog",
+};
+
+static const struct watchdog_ops ni7018_wdd_ops = {
+	.owner = THIS_MODULE,
+	.start = ni7018_start,
+	.stop = ni7018_stop,
+	.ping = ni7018_ping,
+	.set_timeout = ni7018_set_timeout,
+	.get_timeleft = ni7018_get_timeleft,
+};
+
+struct ni7018_attr {
+	struct device_attribute dev_attr;
+	u8 offset;
+	u8 bit;
+};
+#define to_ni7018_attr(_attr) \
+	container_of((_attr), struct ni7018_attr, dev_attr)
+
+static ssize_t wdt_attr_show(struct device *dev,
+			     struct device_attribute *da,
+			     char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	struct ni7018_attr *attr = to_ni7018_attr(da);
+	u8 control;
+	size_t ret;
+
+	mutex_lock(&wdt->lock);
+
+	control = inb(wdt->io_base + attr->offset);
+
+	mutex_unlock(&wdt->lock);
+
+	ret = sprintf(buf, "%u\n", !!(control & attr->bit));
+	return ret;
+}
+
+static ssize_t wdt_attr_store(struct device *dev,
+			      struct device_attribute *da,
+			      const char *buf,
+			      size_t size)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	struct ni7018_attr *attr = to_ni7018_attr(da);
+	unsigned long val;
+	u8 control;
+
+	int ret = kstrtoul(buf, 10, &val);
+
+	if (ret)
+		return ret;
+
+	if (val < 0 || val > 1)
+		return -EINVAL;
+
+	mutex_lock(&wdt->lock);
+
+	control = inb(wdt->io_base + attr->offset);
+	if (val)
+		outb(control | attr->bit, wdt->io_base + attr->offset);
+	else
+		outb(control & ~attr->bit, wdt->io_base + attr->offset);
+
+	mutex_unlock(&wdt->lock);
+	return size;
+}
+
+#define WDT_ATTR(_name, _offset, _bit) \
+	struct ni7018_attr dev_attr_##_name = { \
+		.offset = _offset, \
+		.bit = _bit, \
+		.dev_attr = \
+			__ATTR(_name, S_IWUSR | S_IRUGO, \
+			       wdt_attr_show, wdt_attr_store), \
+	}
+
+static WDT_ATTR(enable_reset, WDT_CTRL, WDT_CTRL_RESET_EN);
+static WDT_ATTR(enable_soft_ping, WDT_RELOAD_CTRL, WDT_RELOAD_PORT_EN);
+static WDT_ATTR(trigger_polarity, WDT_CTRL, WDT_CTRL_TRIG_POLARITY);
+static WDT_ATTR(keepalive_trigger_polarity, WDT_RELOAD_CTRL,
+		WDT_RELOAD_TRIG_POLARITY);
+
+static ssize_t wdt_trig_show(struct device *dev,
+			     struct device_attribute *da,
+			     char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	struct ni7018_attr *attr = to_ni7018_attr(da);
+	u8 control;
+	size_t ret;
+
+	mutex_lock(&wdt->lock);
+
+	control = inb(wdt->io_base + attr->offset);
+
+	mutex_unlock(&wdt->lock);
+
+	if (control & attr->bit)
+		ret = sprintf(buf, "trig%u\n", (control & attr->bit) - 1);
+	else
+		ret = sprintf(buf, "none\n");
+
+	return ret;
+}
+
+static ssize_t wdt_trig_store(struct device *dev,
+			      struct device_attribute *da,
+			      const char *buf,
+			      size_t size)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
+	struct ni7018_attr *attr = to_ni7018_attr(da);
+	unsigned long val;
+	u8 control;
+	int ret;
+
+	if (!strncmp(buf, "trig", 4)) {
+		ret = kstrtoul(buf + 4, 10, &val);
+		if (ret)
+			return ret;
+
+		if (val < WDT_MIN_TRIG_NUM || val > WDT_MAX_TRIG_NUM)
+			return -EINVAL;
+
+		mutex_lock(&wdt->lock);
+
+		control = inb(wdt->io_base + attr->offset);
+		outb((control & ~attr->bit) | (val + 1),
+		     wdt->io_base + attr->offset);
+
+		mutex_unlock(&wdt->lock);
+
+	} else if (!strncmp(buf, "none", 4)) {
+		mutex_lock(&wdt->lock);
+
+		control = inb(wdt->io_base + attr->offset);
+		outb(control & ~attr->bit, wdt->io_base + attr->offset);
+
+		mutex_unlock(&wdt->lock);
+
+	} else {
+		return -EINVAL;
+	}
+
+	return size;
+}
+
+#define WDT_TRIG_ATTR(_name, _offset, _bit) \
+	struct ni7018_attr dev_attr_##_name = { \
+		.offset = _offset, \
+		.bit = _bit, \
+		.dev_attr = \
+			__ATTR(_name, S_IWUSR | S_IRUGO, \
+			       wdt_trig_show, wdt_trig_store), \
+	}
+
+static WDT_TRIG_ATTR(trigger, WDT_CTRL, WDT_CTRL_TRIG);
+static WDT_TRIG_ATTR(keepalive_trigger, WDT_RELOAD_CTRL, WDT_RELOAD_TRIG);
+
+static struct attribute *ni7018_wdt_attrs[] = {
+	&dev_attr_enable_reset.dev_attr.attr,
+	&dev_attr_enable_soft_ping.dev_attr.attr,
+	&dev_attr_trigger_polarity.dev_attr.attr,
+	&dev_attr_keepalive_trigger_polarity.dev_attr.attr,
+	&dev_attr_trigger.dev_attr.attr,
+	&dev_attr_keepalive_trigger.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(ni7018_wdt);
+
+static int ni7018_add(struct acpi_device *device)
+{
+	struct device *dev = &device->dev;
+	struct watchdog_device *wdd;
+	struct ni7018_wdt *wdt;
+	acpi_status status;
+	int ret;
+
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	device->driver_data = wdt;
+	wdt->dev = dev;
+
+	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+				     ni7018_resources, wdt);
+
+	if (ACPI_FAILURE(status) || wdt->io_base == 0) {
+		dev_err(dev, "failed to get resources\n");
+		return -ENODEV;
+	}
+
+	wdd = &wdt->wdd;
+	wdd->info = &ni7018_wdd_info;
+	wdd->ops = &ni7018_wdd_ops;
+	wdd->min_timeout = WDT_MIN_TIMEOUT;
+	wdd->max_timeout = WDT_MAX_TIMEOUT;
+	wdd->timeout = WDT_DEFAULT_TIMEOUT;
+	wdd->parent = dev;
+	wdd->groups = ni7018_wdt_groups;
+
+	mutex_init(&wdt->lock);
+	watchdog_set_drvdata(wdd, wdt);
+	watchdog_set_nowayout(wdd, nowayout);
+
+	ret = watchdog_init_timeout(wdd, timeout, dev);
+	if (ret)
+		dev_err(dev, "unable to set timeout value, using default\n");
+
+	/* Unlock WDT register */
+	outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
+
+	ret = watchdog_register_device(wdd);
+	if (ret) {
+		dev_err(dev, "failed to register watchdog\n");
+		goto err_out;
+	}
+
+	dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
+		wdt->io_base, timeout, nowayout);
+	return 0;
+
+err_out:
+	mutex_destroy(&wdt->lock);
+	return ret;
+}
+
+static int ni7018_remove(struct acpi_device *device)
+{
+	struct ni7018_wdt *wdt = acpi_driver_data(device);
+
+	ni7018_stop(&wdt->wdd);
+	watchdog_unregister_device(&wdt->wdd);
+
+	/* Lock WDT register */
+	outb(LOCK, wdt->io_base + WDT_REG_LOCK);
+
+	mutex_destroy(&wdt->lock);
+	return 0;
+}
+
+static const struct acpi_device_id ni7018_device_ids[] = {
+	{"NIC7018", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, ni7018_device_ids);
+
+static struct acpi_driver ni7018_acpi_driver = {
+	.name = KBUILD_MODNAME,
+	.ids = ni7018_device_ids,
+	.ops = {
+		.add = ni7018_add,
+		.remove = ni7018_remove,
+	},
+};
+
+module_acpi_driver(ni7018_acpi_driver);
+
+MODULE_DESCRIPTION("NI 7018 Watchdog");
+MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4