diff mbox series

[v3,2/2] watchdog: Add Toshiba Visconti watchdog driver

Message ID 20200920051807.288034-3-nobuhiro1.iwamatsu@toshiba.co.jp (mailing list archive)
State Superseded
Headers show
Series Add WDT driver for Toshiba Visconti ARM SoC | expand

Commit Message

Nobuhiro Iwamatsu Sept. 20, 2020, 5:18 a.m. UTC
Add the watchdog driver for Toshiba Visconti series.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
---
 drivers/watchdog/Kconfig        |   8 ++
 drivers/watchdog/Makefile       |   1 +
 drivers/watchdog/visconti_wdt.c | 191 ++++++++++++++++++++++++++++++++
 3 files changed, 200 insertions(+)
 create mode 100644 drivers/watchdog/visconti_wdt.c

Comments

Punit Agrawal Sept. 21, 2020, 7:25 a.m. UTC | #1
Iwamatsu-san,

Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> writes:

> Add the watchdog driver for Toshiba Visconti series.
>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
> ---
>  drivers/watchdog/Kconfig        |   8 ++
>  drivers/watchdog/Makefile       |   1 +
>  drivers/watchdog/visconti_wdt.c | 191 ++++++++++++++++++++++++++++++++
>  3 files changed, 200 insertions(+)
>  create mode 100644 drivers/watchdog/visconti_wdt.c
>

[...]

> diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c
> new file mode 100644
> index 000000000000..4a67b9fe9220
> --- /dev/null
> +++ b/drivers/watchdog/visconti_wdt.c
> @@ -0,0 +1,191 @@
> +// 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/interrupt.h>

interrupt.h doesn't seem to be used. It can be dropped.

> +#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("TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION");

The MODULE_AUTHOR() macro is usually used to represent the driver
authors. Not sure about using it for the organization name which is
already included in the copyright notice. Please drop it or replace it
with the author name / email.

> +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp");
> +MODULE_LICENSE("GPL v2");

Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>

Thanks,
Punit
Nobuhiro Iwamatsu Sept. 21, 2020, 8:46 a.m. UTC | #2
Hi,

Thanks for your review.

On Mon, Sep 21, 2020 at 04:25:44PM +0900, Punit Agrawal wrote:
> Iwamatsu-san,
> 
> Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> writes:
> 
> > Add the watchdog driver for Toshiba Visconti series.
> >
> > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
> > ---
> >  drivers/watchdog/Kconfig        |   8 ++
> >  drivers/watchdog/Makefile       |   1 +
> >  drivers/watchdog/visconti_wdt.c | 191 ++++++++++++++++++++++++++++++++
> >  3 files changed, 200 insertions(+)
> >  create mode 100644 drivers/watchdog/visconti_wdt.c
> >
> 
> [...]
> 
> > diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c
> > new file mode 100644
> > index 000000000000..4a67b9fe9220
> > --- /dev/null
> > +++ b/drivers/watchdog/visconti_wdt.c
> > @@ -0,0 +1,191 @@
> > +// 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/interrupt.h>
> 
> interrupt.h doesn't seem to be used. It can be dropped.
> 

Right. I will remove this.


> > +#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)")");


<snip>


> > +module_platform_driver(visconti_wdt_driver);
> > +
> > +MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver");
> > +MODULE_AUTHOR("TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION");
> 
> The MODULE_AUTHOR() macro is usually used to represent the driver
> authors. Not sure about using it for the organization name which is
> already included in the copyright notice. Please drop it or replace it
> with the author name / email.

Well, it's unnecessary for MODULE_AUTHOR.
I will drop this.

> 
> > +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp");
> > +MODULE_LICENSE("GPL v2");
> 
> Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
> 

Thanks!

> Thanks,
> Punit
> 

Best regards,
  Nobuhiro
diff mbox series

Patch

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..4a67b9fe9220
--- /dev/null
+++ b/drivers/watchdog/visconti_wdt.c
@@ -0,0 +1,191 @@ 
+// 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/interrupt.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("TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION");
+MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp");
+MODULE_LICENSE("GPL v2");