| Message ID | 20200921091235.299774-3-nobuhiro1.iwamatsu@toshiba.co.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add WDT driver for Toshiba Visconti ARM SoC | expand |
On Mon, Sep 21, 2020 at 06:12:35PM +0900, Nobuhiro Iwamatsu wrote: > Add the watchdog driver for Toshiba Visconti series. > > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> > Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp> > --- > drivers/watchdog/Kconfig | 8 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/visconti_wdt.c | 189 ++++++++++++++++++++++++++++++++ > 3 files changed, 198 insertions(+) > create mode 100644 drivers/watchdog/visconti_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index ab7aad5a1e69..0cb078ce5e9d 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1004,6 +1004,14 @@ config PM8916_WATCHDOG > Say Y here to include support watchdog timer embedded into the > pm8916 module. > > +config VISCONTI_WATCHDOG > + tristate "Toshiba Visconti series watchdog support" > + depends on ARCH_VISCONTI || COMPILE_TEST > + select WATCHDOG_CORE > + help > + Say Y here to include support for the watchdog timer in Toshiba > + Visconti SoCs. > + > # X86 (i386 + ia64 + x86_64) Architecture > > config ACQUIRE_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 97bed1d3d97c..a7747e76fd29 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -95,6 +95,7 @@ obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o > obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o > obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o > obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o > +obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o > > # X86 (i386 + ia64 + x86_64) Architecture > obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o > diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c > new file mode 100644 > index 000000000000..9448eaaa51b6 > --- /dev/null > +++ b/drivers/watchdog/visconti_wdt.c > @@ -0,0 +1,189 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2020 TOSHIBA CORPORATION > + * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation > + * Copyright (c) 2020 Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> > + */ > + > +#include <linux/clk.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/watchdog.h> > + > +#define WDT_CNT 0x00 > +#define WDT_MIN 0x04 > +#define WDT_MAX 0x08 > +#define WDT_CTL 0x0c > +#define WDT_CMD 0x10 > +#define WDT_CMD_CLEAR 0x4352 > +#define WDT_CMD_START_STOP 0x5354 > +#define WDT_DIV 0x30 > + > +#define VISCONTI_WDT_FREQ 2000000 /* 2MHz */ > +#define WDT_DEFAULT_TIMEOUT 10U /* 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 visconti_wdt_priv { > + struct watchdog_device wdev; > + void __iomem *base; > + u32 div; > +}; > + > +static int visconti_wdt_start(struct watchdog_device *wdev) > +{ > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; > + > + writel(priv->div, priv->base + WDT_DIV); > + writel(0, priv->base + WDT_MIN); > + writel(timeout, priv->base + WDT_MAX); > + writel(0, priv->base + WDT_CTL); > + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); > + > + return 0; > +} > + > +static int visconti_wdt_stop(struct watchdog_device *wdev) > +{ > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + writel(1, priv->base + WDT_CTL); > + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); > + > + return 0; > +} > + > +static int visconti_wdt_ping(struct watchdog_device *wdd) > +{ > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdd); > + > + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); > + > + return 0; > +} > + > +static unsigned int visconti_wdt_get_timeleft(struct watchdog_device *wdev) > +{ > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; > + u32 cnt = readl(priv->base + WDT_CNT); > + > + if (timeout <= cnt) > + return 0; > + timeout -= cnt; > + > + return timeout / VISCONTI_WDT_FREQ; > +} > + > +static int visconti_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout) > +{ > + u32 val; > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + wdev->timeout = timeout; > + val = wdev->timeout * VISCONTI_WDT_FREQ; > + > + /* Clear counter before setting timeout because WDT expires */ > + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); > + writel(val, priv->base + WDT_MAX); > + > + return 0; > +} > + > +static const struct watchdog_info visconti_wdt_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, > + .identity = "Visconti Watchdog", > +}; > + > +static const struct watchdog_ops visconti_wdt_ops = { > + .owner = THIS_MODULE, > + .start = visconti_wdt_start, > + .stop = visconti_wdt_stop, > + .ping = visconti_wdt_ping, > + .get_timeleft = visconti_wdt_get_timeleft, > + .set_timeout = visconti_wdt_set_timeout, > +}; > + > +static int visconti_wdt_probe(struct platform_device *pdev) > +{ > + struct watchdog_device *wdev; > + struct visconti_wdt_priv *priv; > + struct device *dev = &pdev->dev; > + struct clk *clk; > + int ret; > + unsigned long clk_freq; > + > + priv = devm_kzalloc(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); > + > + clk = devm_clk_get(dev, NULL); > + if (IS_ERR(clk)) > + return dev_err_probe(dev, PTR_ERR(clk), "Could not get clock\n"); > + > + ret = clk_prepare_enable(clk); > + if (ret) { > + dev_err(dev, "Could not enable clock\n"); > + return ret; > + } There is no clk_disable_unprepare() when the driver is removed, or when devm_watchdog_register_device() fails. For situations like this I suggest to handle cleanup with devm_add_action_or_reset(), which would also simplify error handling. There are lots of examples in other watchdog drivers. Guenter > + > + clk_freq = clk_get_rate(clk); > + if (!clk_freq) { > + clk_disable_unprepare(clk); > + dev_err(dev, "Could not get clock rate\n"); > + return -EINVAL; > + } > + > + priv->div = clk_freq / VISCONTI_WDT_FREQ; > + > + /* Initialize struct watchdog_device. */ > + wdev = &priv->wdev; > + wdev->info = &visconti_wdt_info; > + wdev->ops = &visconti_wdt_ops; > + wdev->parent = dev; > + wdev->min_timeout = 1; > + wdev->max_timeout = 0xffffffff / VISCONTI_WDT_FREQ; > + wdev->timeout = min(wdev->max_timeout, WDT_DEFAULT_TIMEOUT); > + > + watchdog_set_drvdata(wdev, priv); > + watchdog_set_nowayout(wdev, nowayout); > + watchdog_stop_on_unregister(wdev); > + > + /* This overrides the default timeout only if DT configuration was found */ > + ret = watchdog_init_timeout(wdev, 0, dev); > + if (ret) > + dev_warn(dev, "Specified timeout value invalid, using default\n"); > + > + return devm_watchdog_register_device(dev, wdev); > +} > + > +static const struct of_device_id visconti_wdt_of_match[] = { > + { .compatible = "toshiba,visconti-wdt", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, visconti_wdt_of_match); > + > +static struct platform_driver visconti_wdt_driver = { > + .driver = { > + .name = "visconti_wdt", > + .of_match_table = visconti_wdt_of_match, > + }, > + .probe = visconti_wdt_probe, > +}; > +module_platform_driver(visconti_wdt_driver); > + > +MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver"); > +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp"); > +MODULE_LICENSE("GPL v2"); > -- > 2.27.0 >
Hi, Thanks for you review. On Thu, Oct 01, 2020 at 11:00:38AM -0700, Guenter Roeck wrote: > On Mon, Sep 21, 2020 at 06:12:35PM +0900, Nobuhiro Iwamatsu wrote: > > Add the watchdog driver for Toshiba Visconti series. > > > > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> > > Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp> > > --- > > drivers/watchdog/Kconfig | 8 ++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/visconti_wdt.c | 189 ++++++++++++++++++++++++++++++++ > > 3 files changed, 198 insertions(+) > > create mode 100644 drivers/watchdog/visconti_wdt.c > > > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > > index ab7aad5a1e69..0cb078ce5e9d 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -1004,6 +1004,14 @@ config PM8916_WATCHDOG > > Say Y here to include support watchdog timer embedded into the > > pm8916 module. > > > > +config VISCONTI_WATCHDOG > > + tristate "Toshiba Visconti series watchdog support" > > + depends on ARCH_VISCONTI || COMPILE_TEST > > + select WATCHDOG_CORE > > + help > > + Say Y here to include support for the watchdog timer in Toshiba > > + Visconti SoCs. > > + > > # X86 (i386 + ia64 + x86_64) Architecture > > > > config ACQUIRE_WDT > > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > > index 97bed1d3d97c..a7747e76fd29 100644 > > --- a/drivers/watchdog/Makefile > > +++ b/drivers/watchdog/Makefile > > @@ -95,6 +95,7 @@ obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o > > obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o > > obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o > > obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o > > +obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o > > > > # X86 (i386 + ia64 + x86_64) Architecture > > obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o > > diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c > > new file mode 100644 > > index 000000000000..9448eaaa51b6 > > --- /dev/null > > +++ b/drivers/watchdog/visconti_wdt.c > > @@ -0,0 +1,189 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (c) 2020 TOSHIBA CORPORATION > > + * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation > > + * Copyright (c) 2020 Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> > > + */ > > + > > +#include <linux/clk.h> > > +#include <linux/io.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/platform_device.h> > > +#include <linux/watchdog.h> > > + > > +#define WDT_CNT 0x00 > > +#define WDT_MIN 0x04 > > +#define WDT_MAX 0x08 > > +#define WDT_CTL 0x0c > > +#define WDT_CMD 0x10 > > +#define WDT_CMD_CLEAR 0x4352 > > +#define WDT_CMD_START_STOP 0x5354 > > +#define WDT_DIV 0x30 > > + > > +#define VISCONTI_WDT_FREQ 2000000 /* 2MHz */ > > +#define WDT_DEFAULT_TIMEOUT 10U /* 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 visconti_wdt_priv { > > + struct watchdog_device wdev; > > + void __iomem *base; > > + u32 div; > > +}; > > + > > +static int visconti_wdt_start(struct watchdog_device *wdev) > > +{ > > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; > > + > > + writel(priv->div, priv->base + WDT_DIV); > > + writel(0, priv->base + WDT_MIN); > > + writel(timeout, priv->base + WDT_MAX); > > + writel(0, priv->base + WDT_CTL); > > + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); > > + > > + return 0; > > +} > > + > > +static int visconti_wdt_stop(struct watchdog_device *wdev) > > +{ > > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + writel(1, priv->base + WDT_CTL); > > + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); > > + > > + return 0; > > +} > > + > > +static int visconti_wdt_ping(struct watchdog_device *wdd) > > +{ > > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdd); > > + > > + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); > > + > > + return 0; > > +} > > + > > +static unsigned int visconti_wdt_get_timeleft(struct watchdog_device *wdev) > > +{ > > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; > > + u32 cnt = readl(priv->base + WDT_CNT); > > + > > + if (timeout <= cnt) > > + return 0; > > + timeout -= cnt; > > + > > + return timeout / VISCONTI_WDT_FREQ; > > +} > > + > > +static int visconti_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout) > > +{ > > + u32 val; > > + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + wdev->timeout = timeout; > > + val = wdev->timeout * VISCONTI_WDT_FREQ; > > + > > + /* Clear counter before setting timeout because WDT expires */ > > + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); > > + writel(val, priv->base + WDT_MAX); > > + > > + return 0; > > +} > > + > > +static const struct watchdog_info visconti_wdt_info = { > > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, > > + .identity = "Visconti Watchdog", > > +}; > > + > > +static const struct watchdog_ops visconti_wdt_ops = { > > + .owner = THIS_MODULE, > > + .start = visconti_wdt_start, > > + .stop = visconti_wdt_stop, > > + .ping = visconti_wdt_ping, > > + .get_timeleft = visconti_wdt_get_timeleft, > > + .set_timeout = visconti_wdt_set_timeout, > > +}; > > + > > +static int visconti_wdt_probe(struct platform_device *pdev) > > +{ > > + struct watchdog_device *wdev; > > + struct visconti_wdt_priv *priv; > > + struct device *dev = &pdev->dev; > > + struct clk *clk; > > + int ret; > > + unsigned long clk_freq; > > + > > + priv = devm_kzalloc(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); > > + > > + clk = devm_clk_get(dev, NULL); > > + if (IS_ERR(clk)) > > + return dev_err_probe(dev, PTR_ERR(clk), "Could not get clock\n"); > > + > > + ret = clk_prepare_enable(clk); > > + if (ret) { > > + dev_err(dev, "Could not enable clock\n"); > > + return ret; > > + } > > There is no clk_disable_unprepare() when the driver is removed, or when > devm_watchdog_register_device() fails. For situations like this I suggest > to handle cleanup with devm_add_action_or_reset(), which would also > simplify error handling. There are lots of examples in other watchdog > drivers. I see. I will fix this with your suggestion. > > Guenter > Best regards, Nobuhiro > > + > > + clk_freq = clk_get_rate(clk); > > + if (!clk_freq) { > > + clk_disable_unprepare(clk); > > + dev_err(dev, "Could not get clock rate\n"); > > + return -EINVAL; > > + } > > + > > + priv->div = clk_freq / VISCONTI_WDT_FREQ; > > + > > + /* Initialize struct watchdog_device. */ > > + wdev = &priv->wdev; > > + wdev->info = &visconti_wdt_info; > > + wdev->ops = &visconti_wdt_ops; > > + wdev->parent = dev; > > + wdev->min_timeout = 1; > > + wdev->max_timeout = 0xffffffff / VISCONTI_WDT_FREQ; > > + wdev->timeout = min(wdev->max_timeout, WDT_DEFAULT_TIMEOUT); > > + > > + watchdog_set_drvdata(wdev, priv); > > + watchdog_set_nowayout(wdev, nowayout); > > + watchdog_stop_on_unregister(wdev); > > + > > + /* This overrides the default timeout only if DT configuration was found */ > > + ret = watchdog_init_timeout(wdev, 0, dev); > > + if (ret) > > + dev_warn(dev, "Specified timeout value invalid, using default\n"); > > + > > + return devm_watchdog_register_device(dev, wdev); > > +} > > + > > +static const struct of_device_id visconti_wdt_of_match[] = { > > + { .compatible = "toshiba,visconti-wdt", }, > > + {} > > +}; > > +MODULE_DEVICE_TABLE(of, visconti_wdt_of_match); > > + > > +static struct platform_driver visconti_wdt_driver = { > > + .driver = { > > + .name = "visconti_wdt", > > + .of_match_table = visconti_wdt_of_match, > > + }, > > + .probe = visconti_wdt_probe, > > +}; > > +module_platform_driver(visconti_wdt_driver); > > + > > +MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver"); > > +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.27.0 > > >
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index ab7aad5a1e69..0cb078ce5e9d 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1004,6 +1004,14 @@ config PM8916_WATCHDOG Say Y here to include support watchdog timer embedded into the pm8916 module. +config VISCONTI_WATCHDOG + tristate "Toshiba Visconti series watchdog support" + depends on ARCH_VISCONTI || COMPILE_TEST + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer in Toshiba + Visconti SoCs. + # X86 (i386 + ia64 + x86_64) Architecture config ACQUIRE_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 97bed1d3d97c..a7747e76fd29 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -95,6 +95,7 @@ obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o +obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c new file mode 100644 index 000000000000..9448eaaa51b6 --- /dev/null +++ b/drivers/watchdog/visconti_wdt.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 TOSHIBA CORPORATION + * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation + * Copyright (c) 2020 Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +#define WDT_CNT 0x00 +#define WDT_MIN 0x04 +#define WDT_MAX 0x08 +#define WDT_CTL 0x0c +#define WDT_CMD 0x10 +#define WDT_CMD_CLEAR 0x4352 +#define WDT_CMD_START_STOP 0x5354 +#define WDT_DIV 0x30 + +#define VISCONTI_WDT_FREQ 2000000 /* 2MHz */ +#define WDT_DEFAULT_TIMEOUT 10U /* 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 visconti_wdt_priv { + struct watchdog_device wdev; + void __iomem *base; + u32 div; +}; + +static int visconti_wdt_start(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; + + writel(priv->div, priv->base + WDT_DIV); + writel(0, priv->base + WDT_MIN); + writel(timeout, priv->base + WDT_MAX); + writel(0, priv->base + WDT_CTL); + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); + + return 0; +} + +static int visconti_wdt_stop(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + + writel(1, priv->base + WDT_CTL); + writel(WDT_CMD_START_STOP, priv->base + WDT_CMD); + + return 0; +} + +static int visconti_wdt_ping(struct watchdog_device *wdd) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdd); + + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); + + return 0; +} + +static unsigned int visconti_wdt_get_timeleft(struct watchdog_device *wdev) +{ + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ; + u32 cnt = readl(priv->base + WDT_CNT); + + if (timeout <= cnt) + return 0; + timeout -= cnt; + + return timeout / VISCONTI_WDT_FREQ; +} + +static int visconti_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout) +{ + u32 val; + struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev); + + wdev->timeout = timeout; + val = wdev->timeout * VISCONTI_WDT_FREQ; + + /* Clear counter before setting timeout because WDT expires */ + writel(WDT_CMD_CLEAR, priv->base + WDT_CMD); + writel(val, priv->base + WDT_MAX); + + return 0; +} + +static const struct watchdog_info visconti_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "Visconti Watchdog", +}; + +static const struct watchdog_ops visconti_wdt_ops = { + .owner = THIS_MODULE, + .start = visconti_wdt_start, + .stop = visconti_wdt_stop, + .ping = visconti_wdt_ping, + .get_timeleft = visconti_wdt_get_timeleft, + .set_timeout = visconti_wdt_set_timeout, +}; + +static int visconti_wdt_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdev; + struct visconti_wdt_priv *priv; + struct device *dev = &pdev->dev; + struct clk *clk; + int ret; + unsigned long clk_freq; + + priv = devm_kzalloc(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); + + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "Could not get clock\n"); + + ret = clk_prepare_enable(clk); + if (ret) { + dev_err(dev, "Could not enable clock\n"); + return ret; + } + + clk_freq = clk_get_rate(clk); + if (!clk_freq) { + clk_disable_unprepare(clk); + dev_err(dev, "Could not get clock rate\n"); + return -EINVAL; + } + + priv->div = clk_freq / VISCONTI_WDT_FREQ; + + /* Initialize struct watchdog_device. */ + wdev = &priv->wdev; + wdev->info = &visconti_wdt_info; + wdev->ops = &visconti_wdt_ops; + wdev->parent = dev; + wdev->min_timeout = 1; + wdev->max_timeout = 0xffffffff / VISCONTI_WDT_FREQ; + wdev->timeout = min(wdev->max_timeout, WDT_DEFAULT_TIMEOUT); + + watchdog_set_drvdata(wdev, priv); + watchdog_set_nowayout(wdev, nowayout); + watchdog_stop_on_unregister(wdev); + + /* This overrides the default timeout only if DT configuration was found */ + ret = watchdog_init_timeout(wdev, 0, dev); + if (ret) + dev_warn(dev, "Specified timeout value invalid, using default\n"); + + return devm_watchdog_register_device(dev, wdev); +} + +static const struct of_device_id visconti_wdt_of_match[] = { + { .compatible = "toshiba,visconti-wdt", }, + {} +}; +MODULE_DEVICE_TABLE(of, visconti_wdt_of_match); + +static struct platform_driver visconti_wdt_driver = { + .driver = { + .name = "visconti_wdt", + .of_match_table = visconti_wdt_of_match, + }, + .probe = visconti_wdt_probe, +}; +module_platform_driver(visconti_wdt_driver); + +MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver"); +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp"); +MODULE_LICENSE("GPL v2");