linux-kernel - Re: [PATCH] watchdog: qcom-wdt: disable pretimeout on timer platform

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Message-ID: <20200204193244.GA21752@roeck-us.net>
Date:   Tue, 4 Feb 2020 11:32:44 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Ansuel Smith <ansuelsmth@...il.com>
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        linux-arm-msm@...r.kernel.org, linux-watchdog@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] watchdog: qcom-wdt: disable pretimeout on timer platform

On Tue, Feb 04, 2020 at 07:43:22PM +0100, Ansuel Smith wrote:
> Some platform like ipq806x doesn't support pretimeout and define
> some interrupts used by qcom,msm-timer. Change the driver to check
> and use pretimeout only on qcom,kpss-wdt as it's the only platform
> that actually supports it.
> 
> Signed-off-by: Ansuel Smith <ansuelsmth@...il.com>
> ---
>  drivers/watchdog/qcom-wdt.c | 31 +++++++++++++++++++++++--------
>  1 file changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
> index a494543d3ae1..195fe49ca32e 100644
> --- a/drivers/watchdog/qcom-wdt.c
> +++ b/drivers/watchdog/qcom-wdt.c
> @@ -40,6 +40,11 @@ static const u32 reg_offset_data_kpss[] = {
>  	[WDT_BITE_TIME] = 0x14,
>  };
>  
> +struct qcom_wdt_match_data {
> +	const u32 *offset;
> +	bool pretimeout;
> +};
> +
>  struct qcom_wdt {
>  	struct watchdog_device	wdd;
>  	unsigned long		rate;
> @@ -179,19 +184,29 @@ static void qcom_clk_disable_unprepare(void *data)
>  	clk_disable_unprepare(data);
>  }
>  
> +static const struct qcom_wdt_match_data match_data_apcs_tmr = {
> +	.offset = reg_offset_data_apcs_tmr,
> +	.pretimeout = false,
> +};
> +
> +static const struct qcom_wdt_match_data match_data_kpss = {
> +	.offset = reg_offset_data_kpss,
> +	.pretimeout = true,
> +};
> +
>  static int qcom_wdt_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct qcom_wdt *wdt;
>  	struct resource *res;
>  	struct device_node *np = dev->of_node;
> -	const u32 *regs;
> +	const struct qcom_wdt_match_data *data;
>  	u32 percpu_offset;
>  	int irq, ret;
>  	struct clk *clk;
>  
> -	regs = of_device_get_match_data(dev);
> -	if (!regs) {
> +	data = of_device_get_match_data(dev);
> +	if (!data && !data->offset) {

This should be ||. However, the second check is really unnecessary
(it would be a coding error).

Guenter

>  		dev_err(dev, "Unsupported QCOM WDT module\n");
>  		return -ENODEV;
>  	}
> @@ -247,7 +262,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
>  
>  	/* check if there is pretimeout support */
>  	irq = platform_get_irq(pdev, 0);
> -	if (irq > 0) {
> +	if (data->pretimeout && irq > 0) {
>  		ret = devm_request_irq(dev, irq, qcom_wdt_isr,
>  				       IRQF_TRIGGER_RISING,
>  				       "wdt_bark", &wdt->wdd);
> @@ -267,7 +282,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
>  	wdt->wdd.min_timeout = 1;
>  	wdt->wdd.max_timeout = 0x10000000U / wdt->rate;
>  	wdt->wdd.parent = dev;
> -	wdt->layout = regs;
> +	wdt->layout = data->offset;
>  
>  	if (readl(wdt_addr(wdt, WDT_STS)) & 1)
>  		wdt->wdd.bootstatus = WDIOF_CARDRESET;
> @@ -311,9 +326,9 @@ static int __maybe_unused qcom_wdt_resume(struct device *dev)
>  static SIMPLE_DEV_PM_OPS(qcom_wdt_pm_ops, qcom_wdt_suspend, qcom_wdt_resume);
>  
>  static const struct of_device_id qcom_wdt_of_table[] = {
> -	{ .compatible = "qcom,kpss-timer", .data = reg_offset_data_apcs_tmr },
> -	{ .compatible = "qcom,scss-timer", .data = reg_offset_data_apcs_tmr },
> -	{ .compatible = "qcom,kpss-wdt", .data = reg_offset_data_kpss },
> +	{ .compatible = "qcom,kpss-timer", .data = &match_data_apcs_tmr },
> +	{ .compatible = "qcom,scss-timer", .data = &match_data_apcs_tmr },
> +	{ .compatible = "qcom,kpss-wdt", .data = &match_data_kpss },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
> -- 
> 2.24.0
>