Hi,
Thanks for your review.
On Sat, Sep 19, 2020 at 07:28:42AM -0700, Guenter Roeck wrote:
> On 9/18/20 3:13 PM, Nobuhiro Iwamatsu wrote:
> > 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 | 195 ++++++++++++++++++++++++++++++++
> > 3 files changed, 204 insertions(+)
> > create mode 100644 drivers/watchdog/visconti_wdt.c
> >
<snip>
> > diff --git a/drivers/watchdog/visconti_wdt.c b/drivers/watchdog/visconti_wdt.c
> > new file mode 100644
> > index 000000000000..cb8a88e4737e
> > --- /dev/null
> > +++ b/drivers/watchdog/visconti_wdt.c
> > @@ -0,0 +1,195 @@
> > +// 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>
> > +#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) ")");
> > +
> Line split is unnecessary (limit is now 100 comlumns)
>
OK, I will fix this.
> > +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)
> > + timeout -= cnt;
> > + else
> > + return 0;
>
> This is a bit awkward. Please consider
>
> if (timeout <= cnt)
> return 0;
> timeout -= cnt;
>
I see. I will apply your suggestion, thanks.
> > +
> > + return timeout / VISCONTI_WDT_FREQ;
> > +}
> > +
> > +static int visconti_wdt_set_timeout(struct watchdog_device *wdev,
> > + unsigned int timeout)
>
> Another unnecessary line split
OK, I will fix this.
>
> > +{
> > + 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");
>
> another one.
OK, I will fix this.
>
> > +
> > + ret = clk_prepare_enable(clk);
> > + if (ret) {
> > + dev_err(dev, "Could not enable clock\n");
> > + return ret;
> > + }
<snip>
Best regards,
Nobuhiro
