Iwamatsu-san,
Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx> writes:
> Add the watchdog driver for Toshiba Visconti series.
>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxx>
> + */
> +
> +#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@xxxxxxxxxxxxx");
> +MODULE_LICENSE("GPL v2");
Reviewed-by: Punit Agrawal <punit1.agrawal@xxxxxxxxxxxxx>
Thanks,
Punit
