watchdog: ni903x_wdt: Add NI 903x/913x watchdog driver

Add support for the watchdog timer on NI cRIO-903x and cDAQ-913x real-
time controllers.

Signed-off-by: Jeff Westfahl <jeff.westfahl@ni.com>
Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

4 files changed, 287 insertions, 0 deletions

diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index 9f9ec9f76039..53dfc73e0171 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -200,6 +200,11 @@ mv64x60_wdt:
 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
+        (default=kernel config parameter)
+-------------------------------------------------
 nuc900_wdt:
 heartbeat: Watchdog heartbeats in seconds.
         (default = 15)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 5f29f72f4691..6f9530318e14 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1217,6 +1217,17 @@ config SBC_EPX_C3_WATCHDOG
           To compile this driver as a module, choose M here: the
           module will be called sbc_epx_c3.
 
+config NI903X_WDT
+        tristate "NI 903x/913x Watchdog"
+        depends on X86 && ACPI
+        select WATCHDOG_CORE
+        ---help---
+          This is the driver for the watchdog timer on the National Instruments
+          903x/913x real-time controllers.
+
+          To compile this driver as a module, choose M here: the module will be
+          called ni903x_wdt.
+
 # M32R Architecture
 
 # M68K Architecture
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index f566753256ab..5a23529091a0 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -126,6 +126,7 @@ obj-$(CONFIG_MACHZ_WDT) += machzwd.o
 obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
 obj-$(CONFIG_INTEL_MID_WATCHDOG) += intel-mid_wdt.o
+obj-$(CONFIG_NI903X_WDT) += ni903x_wdt.o
 
 # M32R Architecture
 
diff --git a/drivers/watchdog/ni903x_wdt.c b/drivers/watchdog/ni903x_wdt.c
new file mode 100644
index 000000000000..dc67742e9018
--- /dev/null
+++ b/drivers/watchdog/ni903x_wdt.c
@@ -0,0 +1,270 @@
+/*
+ * 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+
+#define NIWD_CONTROL    0x01
+#define NIWD_COUNTER2   0x02
+#define NIWD_COUNTER1   0x03
+#define NIWD_COUNTER0   0x04
+#define NIWD_SEED2      0x05
+#define NIWD_SEED1      0x06
+#define NIWD_SEED0      0x07
+
+#define NIWD_IO_SIZE    0x08
+
+#define NIWD_CONTROL_MODE               0x80
+#define NIWD_CONTROL_PROC_RESET         0x20
+#define NIWD_CONTROL_PET                0x10
+#define NIWD_CONTROL_RUNNING            0x08
+#define NIWD_CONTROL_CAPTURECOUNTER     0x04
+#define NIWD_CONTROL_RESET              0x02
+#define NIWD_CONTROL_ALARM              0x01
+
+#define NIWD_PERIOD_NS          30720
+#define NIWD_MIN_TIMEOUT        1
+#define NIWD_MAX_TIMEOUT        515
+#define NIWD_DEFAULT_TIMEOUT    60
+
+#define NIWD_NAME               "ni903x_wdt"
+
+struct ni903x_wdt {
+        struct device *dev;
+        u16 io_base;
+        struct watchdog_device wdd;
+};
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+                 "Watchdog timeout in seconds. (default="
+                 __MODULE_STRING(NIWD_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) ")");
+
+static void ni903x_start(struct ni903x_wdt *wdt)
+{
+        u8 control = inb(wdt->io_base + NIWD_CONTROL);
+
+        outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
+        outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
+}
+
+static int ni903x_wdd_set_timeout(struct watchdog_device *wdd,
+                                  unsigned int timeout)
+{
+        struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
+        u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS);
+
+        outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2);
+        outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1);
+        outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0);
+
+        wdd->timeout = timeout;
+
+        return 0;
+}
+
+static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd)
+{
+        struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
+        u8 control, counter0, counter1, counter2;
+        u32 counter;
+
+        control = inb(wdt->io_base + NIWD_CONTROL);
+        control |= NIWD_CONTROL_CAPTURECOUNTER;
+        outb(control, wdt->io_base + NIWD_CONTROL);
+
+        counter2 = inb(wdt->io_base + NIWD_COUNTER2);
+        counter1 = inb(wdt->io_base + NIWD_COUNTER1);
+        counter0 = inb(wdt->io_base + NIWD_COUNTER0);
+
+        counter = (counter2 << 16) | (counter1 << 8) | counter0;
+
+        return counter / (1000000000 / NIWD_PERIOD_NS);
+}
+
+static int ni903x_wdd_ping(struct watchdog_device *wdd)
+{
+        struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
+        u8 control;
+
+        control = inb(wdt->io_base + NIWD_CONTROL);
+        outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
+
+        return 0;
+}
+
+static int ni903x_wdd_start(struct watchdog_device *wdd)
+{
+        struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
+
+        outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
+             wdt->io_base + NIWD_CONTROL);
+
+        ni903x_wdd_set_timeout(wdd, wdd->timeout);
+        ni903x_start(wdt);
+
+        return 0;
+}
+
+static int ni903x_wdd_stop(struct watchdog_device *wdd)
+{
+        struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
+
+        outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
+
+        return 0;
+}
+
+static acpi_status ni903x_resources(struct acpi_resource *res, void *data)
+{
+        struct ni903x_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 < NIWD_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,
+                                         NIWD_NAME)) {
+                        dev_err(wdt->dev, "failed to get memory region\n");
+                        return AE_ERROR;
+                }
+
+                return AE_OK;
+
+        case ACPI_RESOURCE_TYPE_END_TAG:
+        default:
+                /* Ignore unsupported resources, e.g. IRQ */
+                return AE_OK;
+        }
+}
+
+static const struct watchdog_info ni903x_wdd_info = {
+        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+        .identity = "NI Watchdog",
+};
+
+static const struct watchdog_ops ni903x_wdd_ops = {
+        .owner = THIS_MODULE,
+        .start = ni903x_wdd_start,
+        .stop = ni903x_wdd_stop,
+        .ping = ni903x_wdd_ping,
+        .set_timeout = ni903x_wdd_set_timeout,
+        .get_timeleft = ni903x_wdd_get_timeleft,
+};
+
+static int ni903x_acpi_add(struct acpi_device *device)
+{
+        struct device *dev = &device->dev;
+        struct watchdog_device *wdd;
+        struct ni903x_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,
+                                     ni903x_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 = &ni903x_wdd_info;
+        wdd->ops = &ni903x_wdd_ops;
+        wdd->min_timeout = NIWD_MIN_TIMEOUT;
+        wdd->max_timeout = NIWD_MAX_TIMEOUT;
+        wdd->timeout = NIWD_DEFAULT_TIMEOUT;
+        wdd->parent = dev;
+        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");
+
+        ret = watchdog_register_device(wdd);
+        if (ret) {
+                dev_err(dev, "failed to register watchdog\n");
+                return ret;
+        }
+
+        /* Switch from boot mode to user mode */
+        outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE,
+             wdt->io_base + NIWD_CONTROL);
+
+        dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
+                wdt->io_base, timeout, nowayout);
+
+        return 0;
+}
+
+static int ni903x_acpi_remove(struct acpi_device *device)
+{
+        struct ni903x_wdt *wdt = acpi_driver_data(device);
+
+        ni903x_wdd_stop(&wdt->wdd);
+        watchdog_unregister_device(&wdt->wdd);
+
+        return 0;
+}
+
+static const struct acpi_device_id ni903x_device_ids[] = {
+        {"NIC775C", 0},
+        {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
+
+static struct acpi_driver ni903x_acpi_driver = {
+        .name = NIWD_NAME,
+        .ids = ni903x_device_ids,
+        .ops = {
+                .add = ni903x_acpi_add,
+                .remove = ni903x_acpi_remove,
+        },
+};
+
+module_acpi_driver(ni903x_acpi_driver);
+
+MODULE_DESCRIPTION("NI 903x Watchdog");
+MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
+MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
+MODULE_LICENSE("GPL");