Re: [RFC 1/4] watchdog: ni9x3x_wdt: Add NI 903x/913x watchdog driver

[Guenter Roeck <linux@roeck-us.net>]

On 02/04/2016 05:28 PM, Kyle Roeschley wrote:
> 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>
> ---
>   drivers/watchdog/Kconfig      |  11 ++
>   drivers/watchdog/Makefile     |   1 +
>   drivers/watchdog/ni9x3x_wdt.c | 264 ++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 276 insertions(+)
>   create mode 100644 drivers/watchdog/ni9x3x_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 0f6d851..18bd13a 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1214,6 +1214,17 @@ config SBC_EPX_C3_WATCHDOG
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called sbc_epx_c3.
>
> +config NI9X3X_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 ni9x3x_wdt.
> +
>   # M32R Architecture
>
>   # M68K Architecture
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index f566753..527978b 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_NI9X3X_WDT) += ni9x3x_wdt.o
>
>   # M32R Architecture
>
> diff --git a/drivers/watchdog/ni9x3x_wdt.c b/drivers/watchdog/ni9x3x_wdt.c
> new file mode 100644
> index 0000000..2cb5627
> --- /dev/null
> +++ b/drivers/watchdog/ni9x3x_wdt.c
> @@ -0,0 +1,264 @@
> +/*
> + * Copyright (C) 2013 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/interrupt.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 NI9X3X_WDT_NAME		"ni9x3x_wdt"
> +
> +#define to_ni9x3x_wdt(_wdog)	container_of(_wdog, struct ni9x3x_wdt, wdog)
> +
> +struct ni9x3x_wdt {
> +	struct acpi_device *acpi_device;
> +	u16 io_base;
> +	u16 io_size;
> +	spinlock_t lock;
> +	struct watchdog_device wdog;
> +};
> +
> +static void ni9x3x_wdt_start(struct ni9x3x_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 ni9x3x_wdt_wdd_set_timeout(struct watchdog_device *wdd,
> +				      unsigned int timeout)
> +{
> +	struct ni9x3x_wdt *wdt = to_ni9x3x_wdt(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);
> +

This function has to set wdd->timeout to the actually configured timeout value,
ie
	wdd->timeout = timeout;

is missing.

Guenter

> +	return 0;
> +}
> +
> +static unsigned int ni9x3x_wdt_wdd_get_timeleft(struct watchdog_device *wdd)
> +{
> +	struct ni9x3x_wdt *wdt = to_ni9x3x_wdt(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;
> +	counter = (counter * (u64)NIWD_PERIOD_NS) / 1000000000;
> +
> +	return (unsigned int)counter;
> +}
> +
> +static int ni9x3x_wdt_wdd_start(struct watchdog_device *wdd)
> +{
> +	struct ni9x3x_wdt *wdt = to_ni9x3x_wdt(wdd);
> +
> +	outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
> +	     wdt->io_base + NIWD_CONTROL);
> +
> +	ni9x3x_wdt_wdd_set_timeout(wdd, wdd->timeout);
> +	ni9x3x_wdt_start(wdt);
> +
> +	return 0;
> +}
> +
> +static int ni9x3x_wdt_wdd_stop(struct watchdog_device *wdd)
> +{
> +	struct ni9x3x_wdt *wdt = to_ni9x3x_wdt(wdd);
> +
> +	outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
> +
> +	return 0;
> +}
> +
> +static int ni9x3x_wdt_wdd_ping(struct watchdog_device *wdd)
> +{
> +	struct ni9x3x_wdt *wdt = to_ni9x3x_wdt(wdd);
> +	u8 control;
> +
> +	control = inb(wdt->io_base + NIWD_CONTROL);
> +	outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
> +
> +	return 0;
> +}
> +
> +static acpi_status ni9x3x_wdt_resources(struct acpi_resource *res, void *data)
> +{
> +	struct ni9x3x_wdt *wdt = data;
> +
> +	switch (res->type) {
> +	case ACPI_RESOURCE_TYPE_IO:
> +		if (wdt->io_base != 0 || wdt->io_size != 0) {
> +			dev_err(&wdt->acpi_device->dev,
> +				 "too many IO resources\n");
> +			return AE_ERROR;
> +		}
> +
> +		wdt->io_base = res->data.io.minimum;
> +		wdt->io_size = res->data.io.address_length;
> +
> +		return AE_OK;
> +
> +	case ACPI_RESOURCE_TYPE_END_TAG:
> +		return AE_OK;
> +
> +	default:
> +		dev_err(&wdt->acpi_device->dev,
> +			"unsupported resource type %d\n", res->type);
> +		return AE_ERROR;
> +	}
> +
> +	return AE_OK;
> +}
> +
> +static int ni9x3x_wdt_acpi_remove(struct acpi_device *device)
> +{
> +	struct ni9x3x_wdt *wdt = acpi_driver_data(device);
> +
> +	ni9x3x_wdt_wdd_stop(&wdt->wdog);
> +	watchdog_unregister_device(&wdt->wdog);
> +
> +	return 0;
> +}
> +
> +static const struct watchdog_info ni9x3x_wdt_wdd_info = {
> +	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> +	.identity = "NI Watchdog",
> +};
> +
> +static const struct watchdog_ops ni9x3x_wdt_wdd_ops = {
> +	.owner		= THIS_MODULE,
> +	.start		= ni9x3x_wdt_wdd_start,
> +	.stop		= ni9x3x_wdt_wdd_stop,
> +	.ping		= ni9x3x_wdt_wdd_ping,
> +	.set_timeout	= ni9x3x_wdt_wdd_set_timeout,
> +	.get_timeleft	= ni9x3x_wdt_wdd_get_timeleft,
> +};
> +
> +static int ni9x3x_wdt_acpi_add(struct acpi_device *device)
> +{
> +	struct ni9x3x_wdt *wdt;
> +	acpi_status status;
> +	int ret;
> +
> +	wdt = devm_kzalloc(&device->dev, sizeof(*wdt), GFP_KERNEL);
> +	if (!wdt)
> +		return -ENOMEM;
> +
> +	device->driver_data = wdt;
> +	wdt->acpi_device = device;
> +
> +	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
> +				     ni9x3x_wdt_resources, wdt);
> +	if (ACPI_FAILURE(status) || wdt->io_base == 0 ||
> +	    wdt->io_size != NIWD_IO_SIZE) {
> +		dev_err(&device->dev, "failed to get resources\n");
> +		return -ENODEV;
> +	}
> +
> +	if (!devm_request_region(&device->dev, wdt->io_base, wdt->io_size,
> +				 NI9X3X_WDT_NAME)) {
> +		dev_err(&device->dev, "failed to get memory region\n");
> +		return -EBUSY;
> +	}
> +
> +	spin_lock_init(&wdt->lock);
> +
> +	wdt->wdog.info = &ni9x3x_wdt_wdd_info;
> +	wdt->wdog.ops = &ni9x3x_wdt_wdd_ops;
> +	wdt->wdog.min_timeout = NIWD_MIN_TIMEOUT;
> +	wdt->wdog.max_timeout = NIWD_MAX_TIMEOUT;
> +	wdt->wdog.timeout = NIWD_DEFAULT_TIMEOUT;
> +	wdt->wdog.parent = &device->dev;
> +
> +	ret = watchdog_register_device(&wdt->wdog);
> +	if (ret) {
> +		dev_err(&device->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_info(&wdt->acpi_device->dev, "IO range 0x%04X-0x%04X\n",
> +		 wdt->io_base, wdt->io_base + wdt->io_size - 1);
> +	return 0;
> +}
> +
> +static const struct acpi_device_id ni9x3x_wdt_device_ids[] = {
> +	{"NIC775C", 0},
> +	{"", 0},
> +};
> +
> +static struct acpi_driver ni9x3x_wdt_acpi_driver = {
> +	.name = NI9X3X_WDT_NAME,
> +	.ids = ni9x3x_wdt_device_ids,
> +	.ops = {
> +		.add = ni9x3x_wdt_acpi_add,
> +		.remove = ni9x3x_wdt_acpi_remove,
> +		},
> +};
> +
> +static int __init ni9x3x_wdt_init(void)
> +{
> +	return acpi_bus_register_driver(&ni9x3x_wdt_acpi_driver);
> +}
> +
> +static void __exit ni9x3x_wdt_exit(void)
> +{
> +	acpi_bus_unregister_driver(&ni9x3x_wdt_acpi_driver);
> +}
> +
> +module_init(ni9x3x_wdt_init);
> +module_exit(ni9x3x_wdt_exit);
> +
> +MODULE_DEVICE_TABLE(acpi, ni9x3x_wdt_device_ids);
> +MODULE_DESCRIPTION("NI Watchdog");
> +MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
> +MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
> +MODULE_LICENSE("GPL v2");
>