Re: [PATCH v6] watchdog: nic7018_wdt: Add NIC7018 watchdog driver

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

On Thu, 2016-12-29 at 02:09 -0800, Guenter Roeck wrote:
> On 12/28/2016 10:56 PM, Hui Chun Ong wrote:
> > 
> > Add support for the watchdog timer on PXI Embedded Controller.
> > 
> > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> > Signed-off-by: Hui Chun Ong <hui.chun.ong@ni.com>
> > ---
> > v5: Add Reviewed-by.
> There is no need to re-send a patch just to add a Reviewed-by:.
> 
> Guenter
> 
Is there anything else that I need to do to get the patch into
mainline?

> > 
> > 
> > v4: Remove nic7018_stop() from nic7018_remove().
> >     Lock WDT registers when watchdog_register_device() call failed.
> > 
> > v3: Update timeout calculation from miliseconds to seconds.
> >     Reorder watchdog_regiser_device() call to prevent potential
> > race condition.
> > 
> > v2: Remove mutex lock and platform_device *pdev fields from struct
> > nic7018_wdt.
> >     Update config NIC7018_WDT description.
> >     Update nic7018_get_config() to never return error.
> >     Remove checking for IO resource size in nic7018_probe().
> > 
> > v1: Remove non-standard attributes.
> >     Change from acpi_driver to platform_driver.
> >     Rename driver from ni7018_wdt to nic7018_wdt.
> > ---
> >  Documentation/watchdog/watchdog-parameters.txt |   5 +
> >  drivers/watchdog/Kconfig                       |  10 +
> >  drivers/watchdog/Makefile                      |   1 +
> >  drivers/watchdog/nic7018_wdt.c                 | 265
> > +++++++++++++++++++++++++
> >  4 files changed, 281 insertions(+)
> >  create mode 100644 drivers/watchdog/nic7018_wdt.c
> > 
> > diff --git a/Documentation/watchdog/watchdog-parameters.txt
> > b/Documentation/watchdog/watchdog-parameters.txt
> > index e21850e..4f7d86d 100644
> > --- a/Documentation/watchdog/watchdog-parameters.txt
> > +++ b/Documentation/watchdog/watchdog-parameters.txt
> > @@ -209,6 +209,11 @@ timeout: Initial watchdog timeout in seconds
> > (0<timeout<516, default=60)
> >  nowayout: Watchdog cannot be stopped once started
> >  	(default=kernel config parameter)
> >  -------------------------------------------------
> > +nic7018_wdt:
> > +timeout: Initial watchdog timeout in seconds (0<timeout<464,
> > default=80)
> > +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 acb00b5..e20eb42 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -1326,6 +1326,16 @@ config NI903X_WDT
> >  	  To compile this driver as a module, choose M here: the
> > module will be
> >  	  called ni903x_wdt.
> > 
> > +config NIC7018_WDT
> > +	tristate "NIC7018 Watchdog"
> > +	depends on X86 && ACPI
> > +	select WATCHDOG_CORE
> > +	---help---
> > +	  Support for National Instruments NIC7018 Watchdog.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > module will be
> > +	  called nic7018_wdt.
> > +
> >  # M32R Architecture
> > 
> >  # M68K Architecture
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index 0c3d35e..3af3588 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_NIC7018_WDT) += nic7018_wdt.o
> > 
> >  # M32R Architecture
> > 
> > diff --git a/drivers/watchdog/nic7018_wdt.c
> > b/drivers/watchdog/nic7018_wdt.c
> > new file mode 100644
> > index 0000000..dcd2656
> > --- /dev/null
> > +++ b/drivers/watchdog/nic7018_wdt.c
> > @@ -0,0 +1,265 @@
> > +/*
> > + * 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/bitops.h>
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/watchdog.h>
> > +
> > +#define LOCK			0xA5
> > +#define UNLOCK			0x5A
> > +
> > +#define WDT_CTRL_RESET_EN	BIT(7)
> > +#define WDT_RELOAD_PORT_EN	BIT(7)
> > +
> > +#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_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 bool nowayout = WATCHDOG_NOWAYOUT;
> > +module_param(nowayout, bool, 0);
> > +MODULE_PARM_DESC(nowayout,
> > +		 "Watchdog cannot be stopped once started.
> > (default="
> > +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +struct nic7018_wdt {
> > +	u16 io_base;
> > +	u32 period;
> > +	struct watchdog_device wdd;
> > +};
> > +
> > +struct nic7018_config {
> > +	u32 period;
> > +	u8 divider;
> > +};
> > +
> > +static const struct nic7018_config nic7018_configs[] = {
> > +	{  2, 4 },
> > +	{ 32, 5 },
> > +};
> > +
> > +static inline u32 nic7018_timeout(u32 period, u8 counter)
> > +{
> > +	return period * counter - period / 2;
> > +}
> > +
> > +static const struct nic7018_config *nic7018_get_config(u32
> > timeout,
> > +						       u8
> > *counter)
> > +{
> > +	const struct nic7018_config *config;
> > +	u8 count;
> > +
> > +	if (timeout < 30 && timeout != 16) {
> > +		config = &nic7018_configs[0];
> > +		count = timeout / 2 + 1;
> > +	} else {
> > +		config = &nic7018_configs[1];
> > +		count = DIV_ROUND_UP(timeout + 16, 32);
> > +
> > +		if (count > WDT_MAX_COUNTER)
> > +			count = WDT_MAX_COUNTER;
> > +	}
> > +	*counter = count;
> > +	return config;
> > +}
> > +
> > +static int nic7018_set_timeout(struct watchdog_device *wdd,
> > +			       unsigned int timeout)
> > +{
> > +	struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +	const struct nic7018_config *config;
> > +	u8 counter;
> > +
> > +	config = nic7018_get_config(timeout, &counter);
> > +
> > +	outb(counter << 4 | config->divider,
> > +	     wdt->io_base + WDT_PRESET_PRESCALE);
> > +
> > +	wdd->timeout = nic7018_timeout(config->period, counter);
> > +	wdt->period = config->period;
> > +
> > +	return 0;
> > +}
> > +
> > +static int nic7018_start(struct watchdog_device *wdd)
> > +{
> > +	struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +	u8 control;
> > +
> > +	nic7018_set_timeout(wdd, wdd->timeout);
> > +
> > +	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);
> > +
> > +	return 0;
> > +}
> > +
> > +static int nic7018_stop(struct watchdog_device *wdd)
> > +{
> > +	struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +
> > +	outb(0, wdt->io_base + WDT_CTRL);
> > +	outb(0, wdt->io_base + WDT_RELOAD_CTRL);
> > +	outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
> > +
> > +	return 0;
> > +}
> > +
> > +static int nic7018_ping(struct watchdog_device *wdd)
> > +{
> > +	struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +
> > +	outb(1, wdt->io_base + WDT_RELOAD_PORT);
> > +
> > +	return 0;
> > +}
> > +
> > +static unsigned int nic7018_get_timeleft(struct watchdog_device
> > *wdd)
> > +{
> > +	struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +	u8 count;
> > +
> > +	count = inb(wdt->io_base + WDT_COUNT) & 0xF;
> > +	if (!count)
> > +		return 0;
> > +
> > +	return nic7018_timeout(wdt->period, count);
> > +}
> > +
> > +static const struct watchdog_info nic7018_wdd_info = {
> > +	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> > WDIOF_MAGICCLOSE,
> > +	.identity = "NIC7018 Watchdog",
> > +};
> > +
> > +static const struct watchdog_ops nic7018_wdd_ops = {
> > +	.owner = THIS_MODULE,
> > +	.start = nic7018_start,
> > +	.stop = nic7018_stop,
> > +	.ping = nic7018_ping,
> > +	.set_timeout = nic7018_set_timeout,
> > +	.get_timeleft = nic7018_get_timeleft,
> > +};
> > +
> > +static int nic7018_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct watchdog_device *wdd;
> > +	struct nic7018_wdt *wdt;
> > +	struct resource *io_rc;
> > +	int ret;
> > +
> > +	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> > +	if (!wdt)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, wdt);
> > +
> > +	io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
> > +	if (!io_rc) {
> > +		dev_err(dev, "missing IO resources\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (!devm_request_region(dev, io_rc->start,
> > resource_size(io_rc),
> > +				 KBUILD_MODNAME)) {
> > +		dev_err(dev, "failed to get IO region\n");
> > +		return -EBUSY;
> > +	}
> > +
> > +	wdt->io_base = io_rc->start;
> > +	wdd = &wdt->wdd;
> > +	wdd->info = &nic7018_wdd_info;
> > +	wdd->ops = &nic7018_wdd_ops;
> > +	wdd->min_timeout = WDT_MIN_TIMEOUT;
> > +	wdd->max_timeout = WDT_MAX_TIMEOUT;
> > +	wdd->timeout = WDT_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_warn(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) {
> > +		outb(LOCK, wdt->io_base + WDT_REG_LOCK);
> > +		dev_err(dev, "failed to register watchdog\n");
> > +		return ret;
> > +	}
> > +
> > +	dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
> > +		wdt->io_base, timeout, nowayout);
> > +	return 0;
> > +}
> > +
> > +static int nic7018_remove(struct platform_device *pdev)
> > +{
> > +	struct nic7018_wdt *wdt = platform_get_drvdata(pdev);
> > +
> > +	watchdog_unregister_device(&wdt->wdd);
> > +
> > +	/* Lock WDT register */
> > +	outb(LOCK, wdt->io_base + WDT_REG_LOCK);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct acpi_device_id nic7018_device_ids[] = {
> > +	{"NIC7018", 0},
> > +	{"", 0},
> > +};
> > +MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);
> > +
> > +static struct platform_driver watchdog_driver = {
> > +	.probe = nic7018_probe,
> > +	.remove = nic7018_remove,
> > +	.driver = {
> > +		.name = KBUILD_MODNAME,
> > +		.acpi_match_table = ACPI_PTR(nic7018_device_ids),
> > +	},
> > +};
> > +
> > +module_platform_driver(watchdog_driver);
> > +
> > +MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog
> > driver");
> > +MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.7.4
> > 
> >