// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 National Instruments Corp.
*/
#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);
watchdog_init_timeout(wdd, timeout, dev);
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");
