diff options
Diffstat (limited to 'drivers/watchdog/ni903x_wdt.c')
| -rw-r--r-- | drivers/watchdog/ni903x_wdt.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/watchdog/ni903x_wdt.c b/drivers/watchdog/ni903x_wdt.c new file mode 100644 index 000000000..4cebad324 --- /dev/null +++ b/drivers/watchdog/ni903x_wdt.c @@ -0,0 +1,257 @@ +// 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) + 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"); |