Subject: Re: [2/2] drivers/watchdog: ASPEED reference dev tree properties for
 config
To: Guenter Roeck <linux@roeck-us.net>
References: <20170613203818.17399-3-cbostic@linux.vnet.ibm.com>
 <20170624221747.GA10038@roeck-us.net>
Cc: wim@iguana.be, joel@jms.id.au, linux-kernel@vger.kernel.org,
        linux-watchdog@vger.kernel.org, andrew@aj.id.au
From: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Date: Mon, 26 Jun 2017 21:17:25 -0500
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On 6/24/17 5:17 PM, Guenter Roeck wrote:
> On Tue, Jun 13, 2017 at 03:38:18PM -0500, Christopher Bostic wrote:
>> Reference the system device tree when configuring the watchdog.
>> Configure for external signal generation if optional attribute
>> 'external-signal' is present in device tree.  Configure for
>> reset system after timeout if the optional attribute
>> 'no-system-reset' is not present.  Disabling system reset may be
>> required in situations where one of the other watchdogs in the
>> systems is responsible for this.
>>
>> Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
>> ---
>>   drivers/watchdog/aspeed_wdt.c | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
>> index 1c65258..9deb4be 100644
>> --- a/drivers/watchdog/aspeed_wdt.c
>> +++ b/drivers/watchdog/aspeed_wdt.c
>> @@ -140,6 +140,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
>>   {
>>   	struct aspeed_wdt *wdt;
>>   	struct resource *res;
>> +	struct device_node *np;
>>   	int ret;
>>   
>>   	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
>> @@ -170,8 +171,16 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
>>   	 * the SOC and not the full chip
>>   	 */
>>   	wdt->ctrl = WDT_CTRL_RESET_MODE_SOC |
>> -		WDT_CTRL_1MHZ_CLK |
>> -		WDT_CTRL_RESET_SYSTEM;
>> +		WDT_CTRL_1MHZ_CLK;
>> +
>> +	np = pdev->dev.of_node;
>> +	if (np && !of_get_property(np, "no-system-reset", NULL))
>> +		wdt->ctrl |= WDT_CTRL_RESET_SYSTEM;
>> +
> Please use of_property_read_bool(). Also, checking np for NULL is unnecessary
> since the called function does that. Note that the above code as written is
> wrong - if np is NULL, WDT_CTRL_RESET_SYSTEM will no longer be set.

Will make the suggested changes.

Thanks
-Chris

> The new properties should probably start with "aspeed," but I'll leave that
> up to DT maintainers to decide.
>
>> +	if (np && of_get_property(np, "external-signal", NULL))
>> +		wdt->ctrl |= WDT_CTRL_WDT_EXT;
>> +
>> +	writel(wdt->ctrl, wdt->base + WDT_CTRL);
>>   
>>   	if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE)  {
>>   		aspeed_wdt_start(&wdt->wdd);