| Message ID | 20210525184449.57703-3-romain.perier@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add watchdog for Mstar SoCs | expand |
Hi, On 5/25/21 11:44 AM, Romain Perier wrote: > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 355100dad60a..f53634ea0de6 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -980,6 +980,19 @@ config VISCONTI_WATCHDOG > Say Y here to include support for the watchdog timer in Toshiba > Visconti SoCs. > > +config MSC313E_WATCHDOG > + tristate "MStar MSC313e watchdog" > + depends on ARCH_MSTARV7 || COMPILE_TEST > + depends on OF > + select WATCHDOG_CORE > + help > + Say Y here to include support for the Watchdog timer embedded > + into MStar MSC313e chips. This will reboot your system when the > + timeout is reached. > + > + To compile this driver as a module, choose M here: the > + module will be called msc313e_wdt. AFAIK, you don't need the "depends on OF" line since the of*.h headers provide stubs for the cases of CONFIG_OF and/or CONFIG_OF_ADDRESS not set/enabled. Not having that line would also make COMPILE_TEST more effective. Can Rob or anyone else comment on this? thanks.
On 5/25/21 11:44 AM, Romain Perier wrote: > From: Daniel Palmer <daniel@0x0f.com> > > It adds a driver for the IP block handling the watchdog timer found for > Mstar MSC313e SoCs and newer. > > Signed-off-by: Daniel Palmer <daniel@0x0f.com> > Co-developed-by: Romain Perier <romain.perier@gmail.com> > Signed-off-by: Romain Perier <romain.perier@gmail.com> > --- > MAINTAINERS | 1 + > drivers/watchdog/Kconfig | 13 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/msc313e_wdt.c | 173 +++++++++++++++++++++++++++++++++ > 4 files changed, 188 insertions(+) > create mode 100644 drivers/watchdog/msc313e_wdt.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index a0f37adb9e64..fcc10c57298c 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2177,6 +2177,7 @@ F: arch/arm/mach-mstar/ > F: drivers/clk/mstar/ > F: drivers/gpio/gpio-msc313.c > F: drivers/pinctrl/pinctrl-msc313.c > +F: drivers/watchdog/msc313e_wdt.c > F: include/dt-bindings/clock/mstar-* > F: include/dt-bindings/gpio/msc313-gpio.h > F: include/soc/mstar/ > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 355100dad60a..f53634ea0de6 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -980,6 +980,19 @@ config VISCONTI_WATCHDOG > Say Y here to include support for the watchdog timer in Toshiba > Visconti SoCs. > > +config MSC313E_WATCHDOG > + tristate "MStar MSC313e watchdog" > + depends on ARCH_MSTARV7 || COMPILE_TEST > + depends on OF > + select WATCHDOG_CORE > + help > + Say Y here to include support for the Watchdog timer embedded > + into MStar MSC313e chips. This will reboot your system when the > + timeout is reached. > + > + To compile this driver as a module, choose M here: the > + module will be called msc313e_wdt. > + > # X86 (i386 + ia64 + x86_64) Architecture > > config ACQUIRE_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index a7eade8b4d45..7fa392ae3000 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -92,6 +92,7 @@ obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o > obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o > obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o > obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o > +obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o > > # X86 (i386 + ia64 + x86_64) Architecture > obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o > diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c > new file mode 100644 > index 000000000000..434259256967 > --- /dev/null > +++ b/drivers/watchdog/msc313e_wdt.c > @@ -0,0 +1,173 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * MStar WDT driver > + * > + * Copyright (C) 2019 - 2021 Daniel Palmer > + * Copyright (C) 2021 Romain Perier > + * > + */ > + > +#include <linux/platform_device.h> > +#include <linux/of.h> > +#include <linux/of_irq.h> > +#include <linux/module.h> > +#include <linux/watchdog.h> > +#include <linux/io.h> > +#include <linux/clk.h> > +#include <linux/interrupt.h> Alphabetic order, please. Also, pelase drop unneeded include files. The driver doesn't support interrupts, so any interrupt related include file is unnecessary. I also don't see any devicetree specific code except for of_device_id, and that is declared in mod_devicetable.h, not in an of_xxx.h include file. > + > +#define REG_WDT_CLR 0x0 > +#define REG_WDT_MAX_PRD_L 0x10 > +#define REG_WDT_MAX_PRD_H 0x14 > + > +#define MSC313E_WDT_DEFAULT_TIMEOUT 30 > +/* Supports 1 - 350 sec */ Doesn't that depend on the clock freqneucy ? More on that see below. > +#define MSC313E_WDT_MIN_TIMEOUT 1 > +#define MSC313E_WDT_MAX_TIMEOUT 350 > + > +static unsigned int timeout; > + > +module_param(timeout, int, 0); > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); > + > +struct msc313e_wdt_priv { > + void __iomem *base; > + struct device *dev; I don't immediately see where 'dev' is used. > + struct watchdog_device wdev; > + struct clk *clk; > +}; > + > +static int msc313e_wdt_start(struct watchdog_device *wdev) > +{ > + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); > + u32 timeout; > + int err; > + > + err = clk_prepare_enable(priv->clk); > + if (err) { > + dev_err(priv->dev, "failed to enable clock\n"); Ah, here. I am not sure if I like that error message - it is going to be persistent and may create a lot of noise if it is ever seen, and pretty much useless otherwise. Either case, if you insist on the message, I'd suggest to use wdev->parent. > + return err; > + } > + timeout = wdev->timeout * clk_get_rate(priv->clk); How is it guaranteed that this won't overflow ? The maximum timeout is not tied to the clock frequency. This will overflow if the clock frequency is above 0xffffffff / 350 = 12271335 Hz and the timeout is sufficiently large. > + writew(timeout & 0xffff, priv->base + REG_WDT_MAX_PRD_L); > + writew((timeout >> 16) & 0xffff, priv->base + REG_WDT_MAX_PRD_H); > + writew(1, priv->base + REG_WDT_CLR); > + return 0; > +} > + > +static int msc313e_wdt_ping(struct watchdog_device *wdev) > +{ > + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + writew(1, priv->base + REG_WDT_CLR); > + return 0; > +} > + > +static int msc313e_wdt_stop(struct watchdog_device *wdev) > +{ > + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + writew(0, priv->base + REG_WDT_MAX_PRD_L); > + writew(0, priv->base + REG_WDT_MAX_PRD_H); > + writew(0, priv->base + REG_WDT_CLR); > + clk_disable_unprepare(priv->clk); > + return 0; > +} > + > +static int msc313e_wdt_settimeout(struct watchdog_device *wdev, unsigned int new_time) > +{ > + wdev->timeout = new_time; > + > + return msc313e_wdt_start(wdev); > +} > + > +static const struct watchdog_info msc313e_wdt_ident = { > + .identity = "MSC313e watchdog", > + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, > +}; > + > +static const struct watchdog_ops msc313e_wdt_ops = { > + .owner = THIS_MODULE, > + .start = msc313e_wdt_start, > + .stop = msc313e_wdt_stop, > + .ping = msc313e_wdt_ping, > + .set_timeout = msc313e_wdt_settimeout, > +}; > + > +static const struct of_device_id msc313e_wdt_of_match[] = { > + { .compatible = "mstar,msc313e-wdt", }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, msc313e_wdt_of_match); > + > +static int msc313e_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct msc313e_wdt_priv *priv; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(priv->base)) > + return PTR_ERR(priv->base); > + > + priv->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(priv->clk)) { > + dev_err(dev, "No input clock\n"); > + return PTR_ERR(priv->clk); > + } > + > + priv->dev = dev; > + priv->wdev.info = &msc313e_wdt_ident, > + priv->wdev.ops = &msc313e_wdt_ops, > + priv->wdev.parent = dev; > + priv->wdev.min_timeout = MSC313E_WDT_MIN_TIMEOUT; > + priv->wdev.max_timeout = MSC313E_WDT_MAX_TIMEOUT; > + priv->wdev.timeout = MSC313E_WDT_DEFAULT_TIMEOUT; > + > + watchdog_set_drvdata(&priv->wdev, priv); > + > + watchdog_init_timeout(&priv->wdev, timeout, dev); > + watchdog_stop_on_reboot(&priv->wdev); > + watchdog_stop_on_unregister(&priv->wdev); > + > + return devm_watchdog_register_device(dev, &priv->wdev); > +} > + > +static int __maybe_unused msc313e_wdt_suspend(struct device *dev) > +{ > + struct msc313e_wdt_priv *priv = dev_get_drvdata(dev); > + > + if (watchdog_active(&priv->wdev)) > + msc313e_wdt_stop(&priv->wdev); > + > + return 0; > +} > + > +static int __maybe_unused msc313e_wdt_resume(struct device *dev) > +{ > + struct msc313e_wdt_priv *priv = dev_get_drvdata(dev); > + > + if (watchdog_active(&priv->wdev)) > + msc313e_wdt_start(&priv->wdev); > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(msc313e_wdt_pm_ops, msc313e_wdt_suspend, msc313e_wdt_resume); > + > +static struct platform_driver msc313e_wdt_driver = { > + .driver = { > + .name = "msc313e-wdt", > + .of_match_table = msc313e_wdt_of_match, > + .pm = &msc313e_wdt_pm_ops, > + }, > + .probe = msc313e_wdt_probe, > +}; > +module_platform_driver(msc313e_wdt_driver); > + > +MODULE_AUTHOR("Daniel Palmer <daniel@thingy.jp>"); > +MODULE_DESCRIPTION("Watchdog driver for MStar MSC313e"); > +MODULE_LICENSE("GPL v2"); >
On 5/25/21 11:49 AM, Randy Dunlap wrote: > Hi, > > On 5/25/21 11:44 AM, Romain Perier wrote: >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >> index 355100dad60a..f53634ea0de6 100644 >> --- a/drivers/watchdog/Kconfig >> +++ b/drivers/watchdog/Kconfig >> @@ -980,6 +980,19 @@ config VISCONTI_WATCHDOG >> Say Y here to include support for the watchdog timer in Toshiba >> Visconti SoCs. >> >> +config MSC313E_WATCHDOG >> + tristate "MStar MSC313e watchdog" >> + depends on ARCH_MSTARV7 || COMPILE_TEST >> + depends on OF >> + select WATCHDOG_CORE >> + help >> + Say Y here to include support for the Watchdog timer embedded >> + into MStar MSC313e chips. This will reboot your system when the >> + timeout is reached. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called msc313e_wdt. > > AFAIK, you don't need the "depends on OF" line since > the of*.h headers provide stubs for the cases of CONFIG_OF > and/or CONFIG_OF_ADDRESS not set/enabled. > I don't actually see any devicetree API calls in the driver. Guenter > Not having that line would also make COMPILE_TEST more effective. > > Can Rob or anyone else comment on this? > > thanks. >
Hi, Le mar. 25 mai 2021 à 21:52, Guenter Roeck <linux@roeck-us.net> a écrit : > > On 5/25/21 11:44 AM, Romain Perier wrote: > > From: Daniel Palmer <daniel@0x0f.com> > > > > It adds a driver for the IP block handling the watchdog timer found for > > Mstar MSC313e SoCs and newer. > > > > Signed-off-by: Daniel Palmer <daniel@0x0f.com> > > Co-developed-by: Romain Perier <romain.perier@gmail.com> > > Signed-off-by: Romain Perier <romain.perier@gmail.com> > > --- > > MAINTAINERS | 1 + > > drivers/watchdog/Kconfig | 13 +++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/msc313e_wdt.c | 173 +++++++++++++++++++++++++++++++++ > > 4 files changed, 188 insertions(+) > > create mode 100644 drivers/watchdog/msc313e_wdt.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index a0f37adb9e64..fcc10c57298c 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -2177,6 +2177,7 @@ F: arch/arm/mach-mstar/ > > F: drivers/clk/mstar/ > > F: drivers/gpio/gpio-msc313.c > > F: drivers/pinctrl/pinctrl-msc313.c > > +F: drivers/watchdog/msc313e_wdt.c > > F: include/dt-bindings/clock/mstar-* > > F: include/dt-bindings/gpio/msc313-gpio.h > > F: include/soc/mstar/ > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > > index 355100dad60a..f53634ea0de6 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -980,6 +980,19 @@ config VISCONTI_WATCHDOG > > Say Y here to include support for the watchdog timer in Toshiba > > Visconti SoCs. > > > > +config MSC313E_WATCHDOG > > + tristate "MStar MSC313e watchdog" > > + depends on ARCH_MSTARV7 || COMPILE_TEST > > + depends on OF > > + select WATCHDOG_CORE > > + help > > + Say Y here to include support for the Watchdog timer embedded > > + into MStar MSC313e chips. This will reboot your system when the > > + timeout is reached. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called msc313e_wdt. > > + > > # X86 (i386 + ia64 + x86_64) Architecture > > > > config ACQUIRE_WDT > > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > > index a7eade8b4d45..7fa392ae3000 100644 > > --- a/drivers/watchdog/Makefile > > +++ b/drivers/watchdog/Makefile > > @@ -92,6 +92,7 @@ obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o > > obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o > > obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o > > obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o > > +obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o > > > > # X86 (i386 + ia64 + x86_64) Architecture > > obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o > > diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c > > new file mode 100644 > > index 000000000000..434259256967 > > --- /dev/null > > +++ b/drivers/watchdog/msc313e_wdt.c > > @@ -0,0 +1,173 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * MStar WDT driver > > + * > > + * Copyright (C) 2019 - 2021 Daniel Palmer > > + * Copyright (C) 2021 Romain Perier > > + * > > + */ > > + > > +#include <linux/platform_device.h> > > +#include <linux/of.h> > > +#include <linux/of_irq.h> > > +#include <linux/module.h> > > +#include <linux/watchdog.h> > > +#include <linux/io.h> > > +#include <linux/clk.h> > > +#include <linux/interrupt.h> > > Alphabetic order, please. Ack, I will fix it. > Also, please drop unneeded include files. > The driver doesn't support interrupts, so any interrupt related > include file is unnecessary. I also don't see any devicetree specific > code except for of_device_id, and that is declared in mod_devicetable.h, > not in an of_xxx.h include file. Arf, in fact an interrupt was used previously (it triggers when the wdt reaches a specific value that is not necessarily the value of the initial timeout), but I have decided to remove it because not really useful. And I have kept some headers, sorry for that. I will fix it. > > > + > > +#define REG_WDT_CLR 0x0 > > +#define REG_WDT_MAX_PRD_L 0x10 > > +#define REG_WDT_MAX_PRD_H 0x14 > > + > > +#define MSC313E_WDT_DEFAULT_TIMEOUT 30 > > +/* Supports 1 - 350 sec */ > > Doesn't that depend on the clock freqneucy ? > More on that see below. > > > +#define MSC313E_WDT_MIN_TIMEOUT 1 > > +#define MSC313E_WDT_MAX_TIMEOUT 350 > > + > > +static unsigned int timeout; > > + > > +module_param(timeout, int, 0); > > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); > > + > > +struct msc313e_wdt_priv { > > + void __iomem *base; > > + struct device *dev; > > I don't immediately see where 'dev' is used. > > > + struct watchdog_device wdev; > > + struct clk *clk; > > +}; > > + > > +static int msc313e_wdt_start(struct watchdog_device *wdev) > > +{ > > + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + u32 timeout; > > + int err; > > + > > + err = clk_prepare_enable(priv->clk); > > + if (err) { > > + dev_err(priv->dev, "failed to enable clock\n"); > > Ah, here. I am not sure if I like that error message - it is going to be > persistent and may create a lot of noise if it is ever seen, and pretty much > useless otherwise. Either case, if you insist on the message, I'd suggest > to use wdev->parent. Honestly ? It is mostly to avoid silent errors, but I can also return an error directly, yep (I mean just return the error code). The userspace app is supposed to check the error code returned by ioctl. No objection for removing the message (and so priv->dev too). > > > + return err; > > + } > > + timeout = wdev->timeout * clk_get_rate(priv->clk); > > How is it guaranteed that this won't overflow ? The maximum timeout is not > tied to the clock frequency. This will overflow if the clock frequency is > above 0xffffffff / 350 = 12271335 Hz and the timeout is sufficiently large. > Ah good catch ! Mhhhhh we could compute max_timeout dynamically from the probe function. So, we allow the maximum possible value just before the overflow. The units are different but there is something similar in meson_wdt.c . Anyway, I will think about it and propose a fix. Thanks, Romain
diff --git a/MAINTAINERS b/MAINTAINERS index a0f37adb9e64..fcc10c57298c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2177,6 +2177,7 @@ F: arch/arm/mach-mstar/ F: drivers/clk/mstar/ F: drivers/gpio/gpio-msc313.c F: drivers/pinctrl/pinctrl-msc313.c +F: drivers/watchdog/msc313e_wdt.c F: include/dt-bindings/clock/mstar-* F: include/dt-bindings/gpio/msc313-gpio.h F: include/soc/mstar/ diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 355100dad60a..f53634ea0de6 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -980,6 +980,19 @@ config VISCONTI_WATCHDOG Say Y here to include support for the watchdog timer in Toshiba Visconti SoCs. +config MSC313E_WATCHDOG + tristate "MStar MSC313e watchdog" + depends on ARCH_MSTARV7 || COMPILE_TEST + depends on OF + select WATCHDOG_CORE + help + Say Y here to include support for the Watchdog timer embedded + into MStar MSC313e chips. This will reboot your system when the + timeout is reached. + + To compile this driver as a module, choose M here: the + module will be called msc313e_wdt. + # X86 (i386 + ia64 + x86_64) Architecture config ACQUIRE_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index a7eade8b4d45..7fa392ae3000 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -92,6 +92,7 @@ obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o +obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c new file mode 100644 index 000000000000..434259256967 --- /dev/null +++ b/drivers/watchdog/msc313e_wdt.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MStar WDT driver + * + * Copyright (C) 2019 - 2021 Daniel Palmer + * Copyright (C) 2021 Romain Perier + * + */ + +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/module.h> +#include <linux/watchdog.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/interrupt.h> + +#define REG_WDT_CLR 0x0 +#define REG_WDT_MAX_PRD_L 0x10 +#define REG_WDT_MAX_PRD_H 0x14 + +#define MSC313E_WDT_DEFAULT_TIMEOUT 30 +/* Supports 1 - 350 sec */ +#define MSC313E_WDT_MIN_TIMEOUT 1 +#define MSC313E_WDT_MAX_TIMEOUT 350 + +static unsigned int timeout; + +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); + +struct msc313e_wdt_priv { + void __iomem *base; + struct device *dev; + struct watchdog_device wdev; + struct clk *clk; +}; + +static int msc313e_wdt_start(struct watchdog_device *wdev) +{ + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 timeout; + int err; + + err = clk_prepare_enable(priv->clk); + if (err) { + dev_err(priv->dev, "failed to enable clock\n"); + return err; + } + timeout = wdev->timeout * clk_get_rate(priv->clk); + writew(timeout & 0xffff, priv->base + REG_WDT_MAX_PRD_L); + writew((timeout >> 16) & 0xffff, priv->base + REG_WDT_MAX_PRD_H); + writew(1, priv->base + REG_WDT_CLR); + return 0; +} + +static int msc313e_wdt_ping(struct watchdog_device *wdev) +{ + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); + + writew(1, priv->base + REG_WDT_CLR); + return 0; +} + +static int msc313e_wdt_stop(struct watchdog_device *wdev) +{ + struct msc313e_wdt_priv *priv = watchdog_get_drvdata(wdev); + + writew(0, priv->base + REG_WDT_MAX_PRD_L); + writew(0, priv->base + REG_WDT_MAX_PRD_H); + writew(0, priv->base + REG_WDT_CLR); + clk_disable_unprepare(priv->clk); + return 0; +} + +static int msc313e_wdt_settimeout(struct watchdog_device *wdev, unsigned int new_time) +{ + wdev->timeout = new_time; + + return msc313e_wdt_start(wdev); +} + +static const struct watchdog_info msc313e_wdt_ident = { + .identity = "MSC313e watchdog", + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, +}; + +static const struct watchdog_ops msc313e_wdt_ops = { + .owner = THIS_MODULE, + .start = msc313e_wdt_start, + .stop = msc313e_wdt_stop, + .ping = msc313e_wdt_ping, + .set_timeout = msc313e_wdt_settimeout, +}; + +static const struct of_device_id msc313e_wdt_of_match[] = { + { .compatible = "mstar,msc313e-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, msc313e_wdt_of_match); + +static int msc313e_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct msc313e_wdt_priv *priv; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "No input clock\n"); + return PTR_ERR(priv->clk); + } + + priv->dev = dev; + priv->wdev.info = &msc313e_wdt_ident, + priv->wdev.ops = &msc313e_wdt_ops, + priv->wdev.parent = dev; + priv->wdev.min_timeout = MSC313E_WDT_MIN_TIMEOUT; + priv->wdev.max_timeout = MSC313E_WDT_MAX_TIMEOUT; + priv->wdev.timeout = MSC313E_WDT_DEFAULT_TIMEOUT; + + watchdog_set_drvdata(&priv->wdev, priv); + + watchdog_init_timeout(&priv->wdev, timeout, dev); + watchdog_stop_on_reboot(&priv->wdev); + watchdog_stop_on_unregister(&priv->wdev); + + return devm_watchdog_register_device(dev, &priv->wdev); +} + +static int __maybe_unused msc313e_wdt_suspend(struct device *dev) +{ + struct msc313e_wdt_priv *priv = dev_get_drvdata(dev); + + if (watchdog_active(&priv->wdev)) + msc313e_wdt_stop(&priv->wdev); + + return 0; +} + +static int __maybe_unused msc313e_wdt_resume(struct device *dev) +{ + struct msc313e_wdt_priv *priv = dev_get_drvdata(dev); + + if (watchdog_active(&priv->wdev)) + msc313e_wdt_start(&priv->wdev); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(msc313e_wdt_pm_ops, msc313e_wdt_suspend, msc313e_wdt_resume); + +static struct platform_driver msc313e_wdt_driver = { + .driver = { + .name = "msc313e-wdt", + .of_match_table = msc313e_wdt_of_match, + .pm = &msc313e_wdt_pm_ops, + }, + .probe = msc313e_wdt_probe, +}; +module_platform_driver(msc313e_wdt_driver); + +MODULE_AUTHOR("Daniel Palmer <daniel@thingy.jp>"); +MODULE_DESCRIPTION("Watchdog driver for MStar MSC313e"); +MODULE_LICENSE("GPL v2");