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[V2,0/3] add UniPhier watchdog support

Message ID 1496740294-12653-1-git-send-email-hayashibara.keiji@socionext.com
Headers show
Series add UniPhier watchdog support | expand

Message

Keiji Hayashibara June 6, 2017, 9:11 a.m. UTC
This series adds support for watchdog timer implemented on UniPhier LD11 and
LD20 SoCs. This driver supports watchdog and system reset for SoCs.

patch V1
http://www.spinics.net/lists/linux-watchdog/msg11782.html

Changes between V2 and V1
=========================
1. Add barrier code in uniphier_watchdog_ping() and __uniphier_watchdog_start().

 When writing WDTCTRL_CLEAR to WDTCTRL register, WDTCTRL_STATUS is updated
 about 62.5usec(2cycle of 32kHz) later. However, if WDTCTRL_CLEAR is written
 before WDTCTRL_STATUS is updated, it can't reboot as SoC specification.
 Therefore, I added barrier code, it waits until WDTCTRL_STATUS is updated.
   
2. Fix issues according to review comments.

 * Use WDOG_STOP_ON_REBOOT instead of shutdown method of struct platform_driver.
 * Separate uniphier-wdt bindings documentation as a patch.
 * Remove delay.h and add bitops.h header file.
 * Use devm_watchdog_register_device().
 * Remove unnecessary code.

Keiji Hayashibara (3):
  devicetree: add UniPhier WDT devicetree bindings documentation
  watchdog: uniphier: add UniPhier watchdog driver
  arm64: dts: uniphier: add watchdog node for LD11 and LD20

 .../devicetree/bindings/watchdog/uniphier-wdt.txt  |  20 ++
 Documentation/watchdog/watchdog-parameters.txt     |   6 +
 arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi   |   4 +
 arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi   |   4 +
 drivers/watchdog/Kconfig                           |  11 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/uniphier_wdt.c                    | 275 +++++++++++++++++++++
 7 files changed, 321 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
 create mode 100644 drivers/watchdog/uniphier_wdt.c

-- 
2.7.4

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Comments

Keiji Hayashibara June 8, 2017, 5:51 a.m. UTC | #1
Hello Yamada-san,

> > +

> > +#include <linux/module.h>

> > +#include <linux/mfd/syscon.h>

> > +#include <linux/of.h>

> > +#include <linux/platform_device.h>

> > +#include <linux/regmap.h>

> > +#include <linux/watchdog.h>

> > +#include <linux/bitops.h>

> 

> I think you should have added <linux/bitops.h> on the top

> to keep the includes alphabetically sorted.


Sorry, I will fix in v3 patch.

----------
Best Regards,
Keiji Hayashibara


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Keiji Hayashibara June 9, 2017, 10:22 a.m. UTC | #2
Hi Guenter,

Thank you for your comment.

> On 06/06/2017 02:11 AM, Keiji Hayashibara wrote:

> > Add a watchdog driver for Socionext UniPhier series SoC.

> > Note that the timeout value for this device must be a power

> > of 2 because of the specification.

> >

> > Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>

> > ---

> >   Documentation/watchdog/watchdog-parameters.txt |   6 +

> >   drivers/watchdog/Kconfig                       |  11 +

> >   drivers/watchdog/Makefile                      |   1 +

> >   drivers/watchdog/uniphier_wdt.c                | 275 +++++++++++++++++++++++++

> >   4 files changed, 293 insertions(+)

> >   create mode 100644 drivers/watchdog/uniphier_wdt.c

> >

> > diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt

> > index 4f7d86d..6f9d7b4 100644

> > --- a/Documentation/watchdog/watchdog-parameters.txt

> > +++ b/Documentation/watchdog/watchdog-parameters.txt

> > @@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, default=60)

> >   nowayout: Watchdog cannot be stopped once started

> >   	(default=kernel config parameter)

> >   -------------------------------------------------

> > +uniphier_wdt:

> > +timeout: Watchdog timeout in power of two seconds.

> > +	(1 <= timeout <= 128, default=64)

> > +nowayout: Watchdog cannot be stopped once started

> > +	(default=kernel config parameter)

> > +-------------------------------------------------

> >   w83627hf_wdt:

> >   wdt_io: w83627hf/thf WDT io port (default 0x2E)

> >   timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60.

> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig

> > index 52a70ee..2a9d9a6 100644

> > --- a/drivers/watchdog/Kconfig

> > +++ b/drivers/watchdog/Kconfig

> > @@ -744,6 +744,17 @@ config ZX2967_WATCHDOG

> >   	  To compile this driver as a module, choose M here: the

> >   	  module will be called zx2967_wdt.

> >

> > +config UNIPHIER_WATCHDOG

> > +	tristate "UniPhier watchdog support"

> > +	depends on ARCH_UNIPHIER || COMPILE_TEST

> > +	select WATCHDOG_CORE

> > +	help

> > +	  Say Y here to include support watchdog timer embedded

> > +	  into the UniPhier system.

> > +

> > +	  To compile this driver as a module, choose M here: the

> > +	  module will be called uniphier_wdt.

> > +

> >   # AVR32 Architecture

> >

> >   config AT32AP700X_WDT

> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile

> > index a2126e2..0928dac 100644

> > --- a/drivers/watchdog/Makefile

> > +++ b/drivers/watchdog/Makefile

> > @@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o

> >   obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o

> >   obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o

> >   obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o

> > +obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o

> >

> >   # AVR32 Architecture

> >   obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o

> > diff --git a/drivers/watchdog/uniphier_wdt.c b/drivers/watchdog/uniphier_wdt.c

> > new file mode 100644

> > index 0000000..75862a0

> > --- /dev/null

> > +++ b/drivers/watchdog/uniphier_wdt.c

> > @@ -0,0 +1,275 @@

> > +/*

> > + * Watchdog driver for the UniPhier watchdog timer

> > + *

> > + * (c) Copyright 2014 Panasonic Corporation

> > + * (c) Copyright 2016 Socionext Inc.

> > + * All rights reserved.

> > + *

> > + * 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/module.h>

> > +#include <linux/mfd/syscon.h>

> > +#include <linux/of.h>

> > +#include <linux/platform_device.h>

> > +#include <linux/regmap.h>

> > +#include <linux/watchdog.h>

> > +#include <linux/bitops.h>

> > +

> > +/* WDT timer setting register */

> > +#define WDTTIMSET			0x3004

> > +#define   WDTTIMSET_PERIOD_MASK		(0xf << 0)

> > +#define   WDTTIMSET_PERIOD_1_SEC	(0x3 << 0)

> > +#define   WDTTIMSET_PERIOD_2_SEC	(0x4 << 0)

> > +#define   WDTTIMSET_PERIOD_4_SEC	(0x5 << 0)

> > +#define   WDTTIMSET_PERIOD_8_SEC	(0x6 << 0)

> > +#define   WDTTIMSET_PERIOD_16_SEC	(0x7 << 0)

> > +#define   WDTTIMSET_PERIOD_32_SEC	(0x8 << 0)

> > +#define   WDTTIMSET_PERIOD_64_SEC	(0x9 << 0)

> > +#define   WDTTIMSET_PERIOD_128_SEC	(0xa << 0)

> > +

> > +/* WDT reset selection register */

> > +#define WDTRSTSEL			0x3008

> > +#define   WDTRSTSEL_RSTSEL_MASK		(0x3 << 0)

> > +#define   WDTRSTSEL_RSTSEL_BOTH		(0x0 << 0)

> > +#define   WDTRSTSEL_RSTSEL_IRQ_ONLY	(0x2 << 0)

> > +

> > +/* WDT control register */

> > +#define WDTCTRL				0x300c

> > +#define   WDTCTRL_STATUS		BIT(8)

> > +#define   WDTCTRL_CLEAR			BIT(1)

> > +#define   WDTCTRL_ENABLE		BIT(0)

> > +

> > +#define SEC_TO_WDTTIMSET_PRD(sec) \

> > +		(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)

> > +

> > +#define WDTST_TIMEOUT			1000 /* usec */

> > +

> > +#define WDT_DEFAULT_TIMEOUT		64   /* Default is 64 seconds */

> > +#define WDT_PERIOD_MIN			1

> > +#define WDT_PERIOD_MAX			128

> > +

> > +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;

> 

> This should be initialized to 0 (see below).


OK. I fix it.

> > +static bool nowayout = WATCHDOG_NOWAYOUT;

> > +

> > +struct uniphier_wdt_dev {

> > +	struct watchdog_device wdt_dev;

> > +	struct regmap	*regmap;

> > +};

> > +

> > +/*

> > + * UniPhier Watchdog operations

> > + */

> > +static int uniphier_watchdog_ping(struct watchdog_device *w)

> > +{

> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);

> > +	unsigned int val;

> > +	int ret;

> > +

> > +	/* Clear counter */

> > +	ret = regmap_write_bits(wdev->regmap, WDTCTRL,

> > +				WDTCTRL_CLEAR, WDTCTRL_CLEAR);

> > +	if (!ret)

> > +		/*

> > +		 * As SoC specification, after clear counter,

> > +		 * it needs to wait until counter status is 1.

> > +		 */

> > +		ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,

> > +					       (val & WDTCTRL_STATUS),

> > +					       0, WDTST_TIMEOUT);

> > +

> > +	return ret;

> > +}

> > +

> > +static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)

> > +{

> > +	unsigned int val;

> > +	int ret;

> > +

> > +	ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,

> > +				       !(val & WDTCTRL_STATUS),

> > +				       0, WDTST_TIMEOUT);

> > +	if (ret)

> > +		return ret;

> > +

> > +	/* Setup period */

> > +	ret = regmap_write(regmap, WDTTIMSET,

> > +			   SEC_TO_WDTTIMSET_PRD(sec));

> > +	if (ret)

> > +		return ret;

> > +

> > +	/* Enable and clear watchdog */

> > +	ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);

> > +	if (!ret)

> > +		/*

> > +		 * As SoC specification, after clear counter,

> > +		 * it needs to wait until counter status is 1.

> > +		 */

> > +		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,

> > +					       (val & WDTCTRL_STATUS),

> > +					       0, WDTST_TIMEOUT);

> > +

> > +	return ret;

> > +}

> > +

> > +static int __uniphier_watchdog_stop(struct regmap *regmap)

> > +{

> > +	/* Disable and stop watchdog */

> > +	return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);

> > +}

> > +

> > +static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)

> > +{

> > +	int ret;

> > +

> > +	ret = __uniphier_watchdog_stop(regmap);

> > +	if (ret)

> > +		return ret;

> > +

> > +	return __uniphier_watchdog_start(regmap, sec);

> > +}

> > +

> > +static int uniphier_watchdog_start(struct watchdog_device *w)

> > +{

> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);

> > +	unsigned int tmp_timeout;

> > +

> > +	tmp_timeout = roundup_pow_of_two(w->timeout);

> > +

> > +	return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);

> > +}

> > +

> > +static int uniphier_watchdog_stop(struct watchdog_device *w)

> > +{

> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);

> > +

> > +	return __uniphier_watchdog_stop(wdev->regmap);

> > +}

> > +

> > +static int uniphier_watchdog_set_timeout(struct watchdog_device *w,

> > +					 unsigned int t)

> > +{

> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);

> > +	unsigned int tmp_timeout;

> > +	int ret;

> > +

> > +	tmp_timeout = roundup_pow_of_two(t);

> > +	if (tmp_timeout == w->timeout)

> > +		return 0;

> > +

> > +	if (watchdog_active(w)) {

> > +		ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);

> > +		if (ret)

> > +			return ret;

> > +	}

> > +

> > +	w->timeout = tmp_timeout;

> > +

> > +	return 0;

> > +}

> > +

> > +/*

> > + * Kernel Interfaces

> > + */

> > +static const struct watchdog_info uniphier_wdt_info = {

> > +	.identity	= "uniphier-wdt",

> > +	.options	= WDIOF_SETTIMEOUT |

> > +			  WDIOF_KEEPALIVEPING |

> > +			  WDIOF_MAGICCLOSE |

> > +			  WDIOF_OVERHEAT,

> > +};

> > +

> > +static const struct watchdog_ops uniphier_wdt_ops = {

> > +	.owner		= THIS_MODULE,

> > +	.start		= uniphier_watchdog_start,

> > +	.stop		= uniphier_watchdog_stop,

> > +	.ping		= uniphier_watchdog_ping,

> > +	.set_timeout	= uniphier_watchdog_set_timeout,

> > +};

> > +

> > +static int uniphier_wdt_probe(struct platform_device *pdev)

> > +{

> > +	struct device *dev = &pdev->dev;

> > +	struct uniphier_wdt_dev *wdev;

> > +	struct regmap *regmap;

> > +	struct device_node *parent;

> > +	int ret;

> > +

> > +	wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);

> > +	if (!wdev)

> > +		return -ENOMEM;

> > +

> > +	platform_set_drvdata(pdev, wdev);

> > +

> > +	parent = of_get_parent(dev->of_node); /* parent should be syscon node */

> > +	regmap = syscon_node_to_regmap(parent);

> > +	of_node_put(parent);

> > +	if (IS_ERR(regmap))

> > +		return PTR_ERR(regmap);

> > +

> > +	wdev->regmap = regmap;

> > +	wdev->wdt_dev.info = &uniphier_wdt_info;

> > +	wdev->wdt_dev.ops = &uniphier_wdt_ops;

> > +	wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;

> > +	wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;

> > +	wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;

> > +	wdev->wdt_dev.parent = dev;

> > +

> > +	watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);

> 

> This only really makes sense if the default for 'timeout' is 0.

> Otherwise it will never take a timeout from devicetree unless timeout is

> explicitly set to 0 as module parameter, which does not make much sense.


It is certainly so.
I will fix it in next v3 patch.


> > +	watchdog_set_nowayout(&wdev->wdt_dev, nowayout);

> > +	watchdog_stop_on_reboot(&wdev->wdt_dev);

> > +

> > +	watchdog_set_drvdata(&wdev->wdt_dev, wdev);

> > +

> > +	uniphier_watchdog_stop(&wdev->wdt_dev);

> > +	ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);

> > +	if (ret)

> > +		return ret;

> > +

> > +	ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);

> > +	if (ret)

> > +		return ret;

> > +

> > +	dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",

> > +		 wdev->wdt_dev.timeout, nowayout);

> > +

> > +	return 0;

> > +}

> > +

> > +static const struct of_device_id uniphier_wdt_dt_ids[] = {

> > +	{ .compatible = "socionext,uniphier-wdt" },

> > +	{ /* sentinel */ }

> > +};

> > +MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);

> > +

> > +static struct platform_driver uniphier_wdt_driver = {

> > +	.probe		= uniphier_wdt_probe,

> > +	.driver		= {

> > +		.name		= "uniphier-wdt",

> > +		.of_match_table	= uniphier_wdt_dt_ids,

> > +	},

> > +};

> > +

> > +module_platform_driver(uniphier_wdt_driver);

> > +

> > +module_param(timeout, uint, 0000);

> > +MODULE_PARM_DESC(timeout,

> > +	"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="

> > +				__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");

> > +

> > +module_param(nowayout, bool, 0000);

> > +MODULE_PARM_DESC(nowayout,

> > +	"Watchdog cannot be stopped once started (default="

> > +				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

> > +

> > +MODULE_AUTHOR("Socionext Inc.");

> > +MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");

> > +MODULE_LICENSE("GPL v2");

> >

> 

> The license here does not match the license in the header (which states GPL2+).


I will modify in next v3 patch.

----------
Best Regards,
Keiji Hayashibara


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