diff mbox series

[1/2] watchdog: Add watchdog driver for Sunplus SP7021

Message ID 20211112105952.216280-2-xt.hu@cqplus1.com (mailing list archive)
State Changes Requested
Headers show
Series Add watchdog driver for Sunplus SP7021 SoC | expand

Commit Message

Xiantao Hu Nov. 12, 2021, 10:59 a.m. UTC 
Sunplus SP7021 requires watchdog timer support.
Add watchdog driver to enable this.

Signed-off-by: Xiantao Hu <xt.hu@cqplus1.com>
---
 MAINTAINERS                    |   6 +
 drivers/watchdog/Kconfig       |  11 ++
 drivers/watchdog/Makefile      |   1 +
 drivers/watchdog/sunplus_wdt.c | 297 +++++++++++++++++++++++++++++++++
 4 files changed, 315 insertions(+)
 create mode 100644 drivers/watchdog/sunplus_wdt.c

Comments

Guenter Roeck Nov. 12, 2021, 2:45 p.m. UTC | #1 
On 11/12/21 2:59 AM, Xiantao Hu wrote:
> Sunplus SP7021 requires watchdog timer support.
> Add watchdog driver to enable this.
> 
> Signed-off-by: Xiantao Hu <xt.hu@cqplus1.com>
> ---
>   MAINTAINERS                    |   6 +
>   drivers/watchdog/Kconfig       |  11 ++
>   drivers/watchdog/Makefile      |   1 +
>   drivers/watchdog/sunplus_wdt.c | 297 +++++++++++++++++++++++++++++++++
>   4 files changed, 315 insertions(+)
>   create mode 100644 drivers/watchdog/sunplus_wdt.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e0bca0de0..f6a328772 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17933,6 +17933,12 @@ L:	netdev@vger.kernel.org
>   S:	Maintained
>   F:	drivers/net/ethernet/dlink/sundance.c
>   
> +SUNPLUS WATCHDOG DRIVER
> +M:	Xiantao Hu <xt.hu@cqplus1.com>
> +L:	linux-watchdog@vger.kernel.org
> +S:	Maintained
> +F:	drivers/watchdog/sunplus_wdt.c
> +
>   SUPERH
>   M:	Yoshinori Sato <ysato@users.sourceforge.jp>
>   M:	Rich Felker <dalias@libc.org>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index bf59faeb3..1a95df8ed 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -990,6 +990,17 @@ config MSC313E_WATCHDOG
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called msc313e_wdt.
>   
> +config SUNPLUS_WATCHDOG
> +	tristate "Sunplus watchdog support"
> +	depends on ARCH_SUNPLUS || COMPILE_TEST
> +	select WATCHDOG_CORE
> +	help
> +	  Say Y here to include support for the watchdog timer
> +	  in Sunplus SoCs.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called sunplus_wdt.
> +
>   # X86 (i386 + ia64 + x86_64) Architecture
>   
>   config ACQUIRE_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 1bd2d6f37..d6a9e4d0e 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -94,6 +94,7 @@ obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o
>   obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o
>   obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o
>   obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o
> +obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o
>   
>   # X86 (i386 + ia64 + x86_64) Architecture
>   obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
> diff --git a/drivers/watchdog/sunplus_wdt.c b/drivers/watchdog/sunplus_wdt.c
> new file mode 100644
> index 000000000..27f22c518
> --- /dev/null
> +++ b/drivers/watchdog/sunplus_wdt.c
> @@ -0,0 +1,297 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * sunplus Watchdog Driver
> + *
> + * Copyright (C) 2021 Sunplus Technology Co., Ltd.
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/watchdog.h>
> +
> +#define WDT_CTRL                0x00
> +#define WDT_CNT                 0x04
> +
> +#define WDT_STOP				0x3877
> +#define WDT_RESUME				0x4A4B
> +#define WDT_CLRIRQ				0x7482
> +#define WDT_UNLOCK				0xAB00
> +#define WDT_LOCK				0xAB01
> +#define WDT_CONMAX				0xDEAF
> +
> +#define RBUS_WDT_RST        BIT(1)
> +#define STC_WDT_RST         BIT(4)
> +
> +#define MASK_SET(mask)		((mask) | (mask << 16))
> +
> +#define SP_WDT_MAX_TIMEOUT		11
> +#define SP_WDT_MIN_TIMEOUT		1
> +
> +#define STC_CLK				90000
> +
> +#define DEVICE_NAME		"sunplus-wdt"
> +
> +static unsigned int timeout;
> +module_param(timeout, int, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
> +
> +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 sp_wdt_priv {
> +	struct watchdog_device wdev;
> +	void __iomem *base;
> +	void __iomem *miscellaneous;

Please find a better name for this variable. Also, unless I am
missing something, it is only used in the init function. That means
it can be passed to that function as parameter and doesn't need
to be stored in sp_wdt_priv.

> +	struct clk *clk;
> +	struct reset_control *rstc;
> +};
> +
> +static int sp_wdt_restart(struct watchdog_device *wdev,
> +			       unsigned long action, void *data)
> +{
> +	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	void __iomem *base;
> +
> +	base = priv->base;
> +	writel(WDT_STOP, base + WDT_CTRL);
> +	writel(WDT_UNLOCK, base + WDT_CTRL);
> +	writel(0x0001, base + WDT_CNT);
> +	writel(WDT_RESUME, base + WDT_CTRL);
> +
> +	return 0;
> +}
> +
> +/* TIMEOUT_MAX = ffff0/90kHz =11.65,so longer than 11 seconds will time out */
> +static int sp_wdt_ping(struct watchdog_device *wdev)
> +{
> +	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	void __iomem *base = priv->base;
> +	u32 count;
> +
> +	writel(WDT_STOP, base + WDT_CTRL);
> +	writel(WDT_UNLOCK, base + WDT_CTRL);
> +	/* tiemrw_cnt[3:0]cant be write,only [19:4] can be write. */
> +	count = (wdev->timeout * STC_CLK) >> 4;
> +	writel(count, base + WDT_CNT);
> +	writel(WDT_RESUME, base + WDT_CTRL);
> +
> +	return 0;
> +}
> +
> +static int sp_wdt_set_timeout(struct watchdog_device *wdev,
> +				   unsigned int timeout)
> +{
> +	wdev->timeout = timeout;
> +

I would assume this also needs to set the new timeout in HW if
the watchdog is running, or the watchdog could time out before
userspace sends another ping.

> +	return 0;
> +}
> +
> +static int sp_wdt_stop(struct watchdog_device *wdev)
> +{
> +	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	void __iomem *base = priv->base;
> +
> +	writel(WDT_STOP, base + WDT_CTRL);
> +
> +	return 0;
> +}
> +
> +static int sp_wdt_start(struct watchdog_device *wdev)
> +{
> +	int ret;
> +
> +	ret = sp_wdt_set_timeout(wdev, wdev->timeout);

That function never returns an error, so checking for it is
pointless here.

> +	if (ret < 0)
> +		return ret;
> +
> +	sp_wdt_ping(wdev);
> +
> +	return 0;
> +}
> +
> +static unsigned int sp_wdt_get_timeleft(struct watchdog_device *wdev)
> +{
> +	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	void __iomem *base = priv->base;
> +	u32 val;
> +
> +	val = readl(base + WDT_CNT);
> +	val &= 0xffff;
> +	val = val << 4;
> +
> +	return val;
> +}
> +
> +/*
> + * 1.We need to reset watchdog flag(clear watchdog interrupt) here
> + * because watchdog timer driver does not have an interrupt handler,
> + * and before enalbe STC and RBUS watchdog timeout. Otherwise,

enable

> + * the intr is always in the triggered state.
> + * 2.enable STC and RBUS watchdog timeout trigger.
> + * 3.watchdog conuter is running, need to be stopped.

counter

> + */
> +static int sp_wdt_hw_init(struct watchdog_device *wdev)
> +{
> +	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +	void __iomem *base = priv->base;
> +	void __iomem *miscellaneous = priv->miscellaneous;
> +	u32 val;
> +
> +	writel(WDT_CLRIRQ, base + WDT_CTRL);
> +	val = readl(miscellaneous);
> +	val |= MASK_SET(STC_WDT_RST);
> +	val |= MASK_SET(RBUS_WDT_RST);
> +	writel(val, miscellaneous);
> +
> +	sp_wdt_stop(wdev);
> +
> +	return 0;
> +}
> +
> +static const struct watchdog_info sp_wdt_info = {
> +	.identity = DEVICE_NAME,
> +	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> +};
> +
> +static const struct watchdog_ops sp_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = sp_wdt_start,
> +	.stop = sp_wdt_stop,
> +	.ping = sp_wdt_ping,
> +	.set_timeout = sp_wdt_set_timeout,
> +	.get_timeleft = sp_wdt_get_timeleft,
> +	.restart = sp_wdt_restart,
> +};
> +
> +static int sp_wdt_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct sp_wdt_priv *priv;
> +	struct resource *wdt_res;
> +	struct clk *clk;
> +	int err;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(priv->clk)) {
> +		dev_err(dev, "Can't find clock source\n");
> +		return PTR_ERR(priv->clk);
> +	}
> +
> +	err = clk_prepare_enable(clk);
> +	if (err) {
> +		dev_err(dev, "Clock can't be enabled correctly\n");
> +		return err;
> +	}
> +
> +	priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
> +	if (!IS_ERR(priv->rstc))
> +		reset_control_deassert(priv->rstc);
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	priv->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	priv->miscellaneous =
> +	    devm_ioremap(dev, wdt_res->start, resource_size(wdt_res));

Why not use devm_ioremap_resource() ? Or, for that matter,
devm_platform_ioremap_resource() like above ?

> +	if (IS_ERR(priv->miscellaneous))
> +		return PTR_ERR(priv->miscellaneous);
> +
> +	priv->wdev.info = &sp_wdt_info;
> +	priv->wdev.ops = &sp_wdt_ops;
> +	priv->wdev.timeout = SP_WDT_MAX_TIMEOUT;
> +	priv->wdev.max_timeout = SP_WDT_MAX_TIMEOUT;
> +	priv->wdev.min_timeout = SP_WDT_MIN_TIMEOUT;

THis should really use max_hw_heartbeat_ms to let the core
ping the watchdog if larger timeouts are desired.

> +	priv->wdev.parent = dev;
> +
> +	watchdog_set_drvdata(&priv->wdev, priv);
> +	sp_wdt_hw_init(&priv->wdev);
> +
> +	watchdog_init_timeout(&priv->wdev, timeout, dev);
> +	watchdog_set_nowayout(&priv->wdev, nowayout);
> +	watchdog_stop_on_reboot(&priv->wdev);
> +
> +	err = devm_watchdog_register_device(dev, &priv->wdev);

Since you call watchdog_unregister_device() below you can not use
the devm_ function here.

> +	if (unlikely(err))

This is not time critical. Drop the unlikely.

> +		return err;
> +
> +	dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n",
> +		 priv->wdev.timeout, nowayout ? ", nowayout" : "");
> +
> +	return 0;
> +}
> +
> +static int sp_wdt_remove(struct platform_device *pdev)
> +{
> +	struct sp_wdt_priv *priv = platform_get_drvdata(pdev);
> +
> +	watchdog_unregister_device(&priv->wdev);
> +
> +	reset_control_assert(priv->rstc);
> +	clk_disable_unprepare(priv->clk);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id sp_wdt_of_match[] = {
> +	{.compatible = "sunplus,sp7021-wdt", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sp_wdt_of_match);
> +
> +static int __maybe_unused sp_wdt_suspend(struct device *dev)
> +{
> +	struct sp_wdt_priv *priv = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&priv->wdev))
> +		sp_wdt_stop(&priv->wdev);
> +
> +	reset_control_assert(priv->rstc);
> +	clk_disable_unprepare(priv->clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused sp_wdt_resume(struct device *dev)
> +{
> +	struct sp_wdt_priv *priv = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&priv->wdev))
> +		sp_wdt_start(&priv->wdev);
> +
Shouldn't the order be the opposite of the order in the suspend function ?

> +	reset_control_deassert(priv->rstc);
> +	clk_prepare_enable(priv->clk);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(sp_wdt_pm_ops, sp_wdt_suspend, sp_wdt_resume);
> +
> +static struct platform_driver sp_wdt_driver = {
> +	.probe = sp_wdt_probe,
> +	.remove = sp_wdt_remove,
> +	.driver = {
> +		   .name = DEVICE_NAME,
> +		   .of_match_table = sp_wdt_of_match,
> +		   .pm = &sp_wdt_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(sp_wdt_driver);
> +
> +MODULE_AUTHOR("Xiantao Hu <xt.hu@cqplus1.com>");
> +MODULE_DESCRIPTION("Sunplus Watchdog Timer Driver");
> +MODULE_LICENSE("GPL v2");
>
kernel test robot Nov. 21, 2021, 12:33 a.m. UTC | #2 
Hi Xiantao,

I love your patch! Perhaps something to improve:

[auto build test WARNING on pza/reset/next]
[also build test WARNING on robh/for-next linux/master linus/master v5.16-rc1 next-20211118]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Xiantao-Hu/Add-watchdog-driver-for-Sunplus-SP7021-SoC/20211112-191201
base:   https://git.pengutronix.de/git/pza/linux reset/next
config: arm64-randconfig-r023-20211115 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project fbe72e41b99dc7994daac300d208a955be3e4a0a)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/0day-ci/linux/commit/eac808eeed4a851ca5cfef12adefd6df199f62c2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xiantao-Hu/Add-watchdog-driver-for-Sunplus-SP7021-SoC/20211112-191201
        git checkout eac808eeed4a851ca5cfef12adefd6df199f62c2
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/watchdog/sunplus_wdt.c:191:27: warning: variable 'clk' is uninitialized when used here [-Wuninitialized]
           err = clk_prepare_enable(clk);
                                    ^~~
   drivers/watchdog/sunplus_wdt.c:178:17: note: initialize the variable 'clk' to silence this warning
           struct clk *clk;
                          ^
                           = NULL
   1 warning generated.


vim +/clk +191 drivers/watchdog/sunplus_wdt.c

   172	
   173	static int sp_wdt_probe(struct platform_device *pdev)
   174	{
   175		struct device *dev = &pdev->dev;
   176		struct sp_wdt_priv *priv;
   177		struct resource *wdt_res;
   178		struct clk *clk;
   179		int err;
   180	
   181		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
   182		if (!priv)
   183			return -ENOMEM;
   184	
   185		priv->clk = devm_clk_get(dev, NULL);
   186		if (IS_ERR(priv->clk)) {
   187			dev_err(dev, "Can't find clock source\n");
   188			return PTR_ERR(priv->clk);
   189		}
   190	
 > 191		err = clk_prepare_enable(clk);
   192		if (err) {
   193			dev_err(dev, "Clock can't be enabled correctly\n");
   194			return err;
   195		}
   196	
   197		priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
   198		if (!IS_ERR(priv->rstc))
   199			reset_control_deassert(priv->rstc);
   200	
   201		platform_set_drvdata(pdev, priv);
   202	
   203		priv->base = devm_platform_ioremap_resource(pdev, 0);
   204		if (IS_ERR(priv->base))
   205			return PTR_ERR(priv->base);
   206	
   207		wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
   208		priv->miscellaneous =
   209		    devm_ioremap(dev, wdt_res->start, resource_size(wdt_res));
   210		if (IS_ERR(priv->miscellaneous))
   211			return PTR_ERR(priv->miscellaneous);
   212	
   213		priv->wdev.info = &sp_wdt_info;
   214		priv->wdev.ops = &sp_wdt_ops;
   215		priv->wdev.timeout = SP_WDT_MAX_TIMEOUT;
   216		priv->wdev.max_timeout = SP_WDT_MAX_TIMEOUT;
   217		priv->wdev.min_timeout = SP_WDT_MIN_TIMEOUT;
   218		priv->wdev.parent = dev;
   219	
   220		watchdog_set_drvdata(&priv->wdev, priv);
   221		sp_wdt_hw_init(&priv->wdev);
   222	
   223		watchdog_init_timeout(&priv->wdev, timeout, dev);
   224		watchdog_set_nowayout(&priv->wdev, nowayout);
   225		watchdog_stop_on_reboot(&priv->wdev);
   226	
   227		err = devm_watchdog_register_device(dev, &priv->wdev);
   228		if (unlikely(err))
   229			return err;
   230	
   231		dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n",
   232			 priv->wdev.timeout, nowayout ? ", nowayout" : "");
   233	
   234		return 0;
   235	}
   236	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Xiantao Hu Nov. 24, 2021, 10:31 a.m. UTC | #3 
Hi, Guenter Roeck :

Thanks for your review. Sorry I was so focused on fixing code and 
I forgot to respond to the email. I modify the code as you comment
and answer the question.

Thanks
Best Regards,
Xiantao Hu

> -----Original Message-----
> From: Guenter Roeck [mailto:groeck7@gmail.com] On Behalf Of Guenter Roeck
> Sent: Friday, November 12, 2021 10:46 PM
> To: xt.hu[胡先韬] <xt.hu@cqplus1.com>; wim@linux-watchdog.org; p.zabel@pengutronix.de;
> linux-kernel@vger.kernel.org; linux-watchdog@vger.kernel.org; robh+dt@kernel.org;
> devicetree@vger.kernel.org
> Cc: Wells Lu 呂芳騰 <wells.lu@sunplus.com>; qinjian[覃健] <qinjian@cqplus1.com>
> Subject: Re: [PATCH 1/2] watchdog: Add watchdog driver for Sunplus SP7021
> 
> On 11/12/21 2:59 AM, Xiantao Hu wrote:
> > Sunplus SP7021 requires watchdog timer support.
> > Add watchdog driver to enable this.
> >
> > Signed-off-by: Xiantao Hu <xt.hu@cqplus1.com>
...
> > +struct sp_wdt_priv {
> > +	struct watchdog_device wdev;
> > +	void __iomem *base;
> > +	void __iomem *miscellaneous;
> 
> Please find a better name for this variable. Also, unless I am
> missing something, it is only used in the init function. That means
> it can be passed to that function as parameter and doesn't need
> to be stored in sp_wdt_priv.
> 

I will remove the miscellaneous from sp_wdt_priv and pass
to that function as parameter.

> > +	struct clk *clk;
> > +	struct reset_control *rstc;
> > +};
...
> > +static int sp_wdt_set_timeout(struct watchdog_device *wdev,
> > +				   unsigned int timeout)
> > +{
> > +	wdev->timeout = timeout;
> > +
> 
> I would assume this also needs to set the new timeout in HW if
> the watchdog is running, or the watchdog could time out before
> userspace sends another ping.
> 

I will call the ping() after assigning timeout.

> > +	return 0;
> > +}
> > +
...
> > +
> > +static int sp_wdt_start(struct watchdog_device *wdev)
> > +{
> > +	int ret;
> > +
> > +	ret = sp_wdt_set_timeout(wdev, wdev->timeout);
> 
> That function never returns an error, so checking for it is
> pointless here.
> 

I will remove the variable ret.

> > +	if (ret < 0)
> > +		return ret;
> > +
...
> > +/*
> > + * 1.We need to reset watchdog flag(clear watchdog interrupt) here
> > + * because watchdog timer driver does not have an interrupt handler,
> > + * and before enalbe STC and RBUS watchdog timeout. Otherwise,
> 
> enable
> 

I will fix it.

> > + * the intr is always in the triggered state.
> > + * 2.enable STC and RBUS watchdog timeout trigger.
> > + * 3.watchdog conuter is running, need to be stopped.
> 
> counter
> 

I will fix it.

> > + */
...
> > +
> > +	wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > +	priv->miscellaneous =
> > +	    devm_ioremap(dev, wdt_res->start, resource_size(wdt_res));
> 
> Why not use devm_ioremap_resource() ? Or, for that matter,
> devm_platform_ioremap_resource() like above ?
> 

The function of this register is miscellaneous. The register 
accessed here shared by multiple drivers. Use the function 
of devm_platform_ioremap_resource() which internally
call request_mem_region() causes an error. So I handle it 
in this way. Any better ways?

> > +	if (IS_ERR(priv->miscellaneous))
> > +		return PTR_ERR(priv->miscellaneous);
> > +
> > +	priv->wdev.info = &sp_wdt_info;
> > +	priv->wdev.ops = &sp_wdt_ops;
> > +	priv->wdev.timeout = SP_WDT_MAX_TIMEOUT;
> > +	priv->wdev.max_timeout = SP_WDT_MAX_TIMEOUT;
> > +	priv->wdev.min_timeout = SP_WDT_MIN_TIMEOUT;
> 
> THis should really use max_hw_heartbeat_ms to let the core
> ping the watchdog if larger timeouts are desired.
> 

I will add the max_hw_heartbeat_ms and modify the 
ping ().

> > +	priv->wdev.parent = dev;
> > +
> > +	watchdog_set_drvdata(&priv->wdev, priv);
> > +	sp_wdt_hw_init(&priv->wdev);
> > +
> > +	watchdog_init_timeout(&priv->wdev, timeout, dev);
> > +	watchdog_set_nowayout(&priv->wdev, nowayout);
> > +	watchdog_stop_on_reboot(&priv->wdev);
> > +
> > +	err = devm_watchdog_register_device(dev, &priv->wdev);
> 
> Since you call watchdog_unregister_device() below you can not use
> the devm_ function here.
> 

I will drop the function remove() and not call watchdog_unregister_device() .
Use the devm_add_action_or_reset() add reset_control_assert() and
clk_disable_unprepare().

> > +	if (unlikely(err))
> 
> This is not time critical. Drop the unlikely.
> 

I will fix it.

> > +		return err;
> > +
> > +	dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n",
> > +		 priv->wdev.timeout, nowayout ? ", nowayout" : "");
> > +
> > +	return 0;
> > +}
> > +
> > +static int sp_wdt_remove(struct platform_device *pdev)
> > +{
> > +	struct sp_wdt_priv *priv = platform_get_drvdata(pdev);
> > +
> > +	watchdog_unregister_device(&priv->wdev);
> > +
> > +	reset_control_assert(priv->rstc);
> > +	clk_disable_unprepare(priv->clk);
> > +
> > +	return 0;
> > +}
> > +
...
> > +
> > +static int __maybe_unused sp_wdt_resume(struct device *dev)
> > +{
> > +	struct sp_wdt_priv *priv = dev_get_drvdata(dev);
> > +
> > +	if (watchdog_active(&priv->wdev))
> > +		sp_wdt_start(&priv->wdev);
> > +
> Shouldn't the order be the opposite of the order in the suspend function ?
>
 
I will fix it.

> > +	reset_control_deassert(priv->rstc);
> > +	clk_prepare_enable(priv->clk);
> > +
> > +	return 0;
> > +}
> >
...
> >
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e0bca0de0..f6a328772 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17933,6 +17933,12 @@  L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/dlink/sundance.c
 
+SUNPLUS WATCHDOG DRIVER
+M:	Xiantao Hu <xt.hu@cqplus1.com>
+L:	linux-watchdog@vger.kernel.org
+S:	Maintained
+F:	drivers/watchdog/sunplus_wdt.c
+
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
 M:	Rich Felker <dalias@libc.org>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bf59faeb3..1a95df8ed 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -990,6 +990,17 @@  config MSC313E_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called msc313e_wdt.
 
+config SUNPLUS_WATCHDOG
+	tristate "Sunplus watchdog support"
+	depends on ARCH_SUNPLUS || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the watchdog timer
+	  in Sunplus SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sunplus_wdt.
+
 # X86 (i386 + ia64 + x86_64) Architecture
 
 config ACQUIRE_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 1bd2d6f37..d6a9e4d0e 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -94,6 +94,7 @@  obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o
 obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o
 obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o
 obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o
+obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o
 
 # X86 (i386 + ia64 + x86_64) Architecture
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
diff --git a/drivers/watchdog/sunplus_wdt.c b/drivers/watchdog/sunplus_wdt.c
new file mode 100644
index 000000000..27f22c518
--- /dev/null
+++ b/drivers/watchdog/sunplus_wdt.c
@@ -0,0 +1,297 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sunplus Watchdog Driver
+ *
+ * Copyright (C) 2021 Sunplus Technology Co., Ltd.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/watchdog.h>
+
+#define WDT_CTRL                0x00
+#define WDT_CNT                 0x04
+
+#define WDT_STOP				0x3877
+#define WDT_RESUME				0x4A4B
+#define WDT_CLRIRQ				0x7482
+#define WDT_UNLOCK				0xAB00
+#define WDT_LOCK				0xAB01
+#define WDT_CONMAX				0xDEAF
+
+#define RBUS_WDT_RST        BIT(1)
+#define STC_WDT_RST         BIT(4)
+
+#define MASK_SET(mask)		((mask) | (mask << 16))
+
+#define SP_WDT_MAX_TIMEOUT		11
+#define SP_WDT_MIN_TIMEOUT		1
+
+#define STC_CLK				90000
+
+#define DEVICE_NAME		"sunplus-wdt"
+
+static unsigned int timeout;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
+
+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 sp_wdt_priv {
+	struct watchdog_device wdev;
+	void __iomem *base;
+	void __iomem *miscellaneous;
+	struct clk *clk;
+	struct reset_control *rstc;
+};
+
+static int sp_wdt_restart(struct watchdog_device *wdev,
+			       unsigned long action, void *data)
+{
+	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	void __iomem *base;
+
+	base = priv->base;
+	writel(WDT_STOP, base + WDT_CTRL);
+	writel(WDT_UNLOCK, base + WDT_CTRL);
+	writel(0x0001, base + WDT_CNT);
+	writel(WDT_RESUME, base + WDT_CTRL);
+
+	return 0;
+}
+
+/* TIMEOUT_MAX = ffff0/90kHz =11.65,so longer than 11 seconds will time out */
+static int sp_wdt_ping(struct watchdog_device *wdev)
+{
+	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	void __iomem *base = priv->base;
+	u32 count;
+
+	writel(WDT_STOP, base + WDT_CTRL);
+	writel(WDT_UNLOCK, base + WDT_CTRL);
+	/* tiemrw_cnt[3:0]cant be write,only [19:4] can be write. */
+	count = (wdev->timeout * STC_CLK) >> 4;
+	writel(count, base + WDT_CNT);
+	writel(WDT_RESUME, base + WDT_CTRL);
+
+	return 0;
+}
+
+static int sp_wdt_set_timeout(struct watchdog_device *wdev,
+				   unsigned int timeout)
+{
+	wdev->timeout = timeout;
+
+	return 0;
+}
+
+static int sp_wdt_stop(struct watchdog_device *wdev)
+{
+	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	void __iomem *base = priv->base;
+
+	writel(WDT_STOP, base + WDT_CTRL);
+
+	return 0;
+}
+
+static int sp_wdt_start(struct watchdog_device *wdev)
+{
+	int ret;
+
+	ret = sp_wdt_set_timeout(wdev, wdev->timeout);
+	if (ret < 0)
+		return ret;
+
+	sp_wdt_ping(wdev);
+
+	return 0;
+}
+
+static unsigned int sp_wdt_get_timeleft(struct watchdog_device *wdev)
+{
+	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	void __iomem *base = priv->base;
+	u32 val;
+
+	val = readl(base + WDT_CNT);
+	val &= 0xffff;
+	val = val << 4;
+
+	return val;
+}
+
+/*
+ * 1.We need to reset watchdog flag(clear watchdog interrupt) here
+ * because watchdog timer driver does not have an interrupt handler,
+ * and before enalbe STC and RBUS watchdog timeout. Otherwise,
+ * the intr is always in the triggered state.
+ * 2.enable STC and RBUS watchdog timeout trigger.
+ * 3.watchdog conuter is running, need to be stopped.
+ */
+static int sp_wdt_hw_init(struct watchdog_device *wdev)
+{
+	struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	void __iomem *base = priv->base;
+	void __iomem *miscellaneous = priv->miscellaneous;
+	u32 val;
+
+	writel(WDT_CLRIRQ, base + WDT_CTRL);
+	val = readl(miscellaneous);
+	val |= MASK_SET(STC_WDT_RST);
+	val |= MASK_SET(RBUS_WDT_RST);
+	writel(val, miscellaneous);
+
+	sp_wdt_stop(wdev);
+
+	return 0;
+}
+
+static const struct watchdog_info sp_wdt_info = {
+	.identity = DEVICE_NAME,
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops sp_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = sp_wdt_start,
+	.stop = sp_wdt_stop,
+	.ping = sp_wdt_ping,
+	.set_timeout = sp_wdt_set_timeout,
+	.get_timeleft = sp_wdt_get_timeleft,
+	.restart = sp_wdt_restart,
+};
+
+static int sp_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sp_wdt_priv *priv;
+	struct resource *wdt_res;
+	struct clk *clk;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "Can't find clock source\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	err = clk_prepare_enable(clk);
+	if (err) {
+		dev_err(dev, "Clock can't be enabled correctly\n");
+		return err;
+	}
+
+	priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
+	if (!IS_ERR(priv->rstc))
+		reset_control_deassert(priv->rstc);
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	priv->miscellaneous =
+	    devm_ioremap(dev, wdt_res->start, resource_size(wdt_res));
+	if (IS_ERR(priv->miscellaneous))
+		return PTR_ERR(priv->miscellaneous);
+
+	priv->wdev.info = &sp_wdt_info;
+	priv->wdev.ops = &sp_wdt_ops;
+	priv->wdev.timeout = SP_WDT_MAX_TIMEOUT;
+	priv->wdev.max_timeout = SP_WDT_MAX_TIMEOUT;
+	priv->wdev.min_timeout = SP_WDT_MIN_TIMEOUT;
+	priv->wdev.parent = dev;
+
+	watchdog_set_drvdata(&priv->wdev, priv);
+	sp_wdt_hw_init(&priv->wdev);
+
+	watchdog_init_timeout(&priv->wdev, timeout, dev);
+	watchdog_set_nowayout(&priv->wdev, nowayout);
+	watchdog_stop_on_reboot(&priv->wdev);
+
+	err = devm_watchdog_register_device(dev, &priv->wdev);
+	if (unlikely(err))
+		return err;
+
+	dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n",
+		 priv->wdev.timeout, nowayout ? ", nowayout" : "");
+
+	return 0;
+}
+
+static int sp_wdt_remove(struct platform_device *pdev)
+{
+	struct sp_wdt_priv *priv = platform_get_drvdata(pdev);
+
+	watchdog_unregister_device(&priv->wdev);
+
+	reset_control_assert(priv->rstc);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static const struct of_device_id sp_wdt_of_match[] = {
+	{.compatible = "sunplus,sp7021-wdt", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sp_wdt_of_match);
+
+static int __maybe_unused sp_wdt_suspend(struct device *dev)
+{
+	struct sp_wdt_priv *priv = dev_get_drvdata(dev);
+
+	if (watchdog_active(&priv->wdev))
+		sp_wdt_stop(&priv->wdev);
+
+	reset_control_assert(priv->rstc);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused sp_wdt_resume(struct device *dev)
+{
+	struct sp_wdt_priv *priv = dev_get_drvdata(dev);
+
+	if (watchdog_active(&priv->wdev))
+		sp_wdt_start(&priv->wdev);
+
+	reset_control_deassert(priv->rstc);
+	clk_prepare_enable(priv->clk);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(sp_wdt_pm_ops, sp_wdt_suspend, sp_wdt_resume);
+
+static struct platform_driver sp_wdt_driver = {
+	.probe = sp_wdt_probe,
+	.remove = sp_wdt_remove,
+	.driver = {
+		   .name = DEVICE_NAME,
+		   .of_match_table = sp_wdt_of_match,
+		   .pm = &sp_wdt_pm_ops,
+	},
+};
+
+module_platform_driver(sp_wdt_driver);
+
+MODULE_AUTHOR("Xiantao Hu <xt.hu@cqplus1.com>");
+MODULE_DESCRIPTION("Sunplus Watchdog Timer Driver");
+MODULE_LICENSE("GPL v2");