linux-kernel - Re: [PATCH V2 2/2] Input: misc: introduce palmas-pwrbutton

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Date:	Thu, 21 Aug 2014 17:46:05 +0000
From:	"Murphy, Dan" <dmurphy@...com>
To:	"Menon, Nishanth" <nm@...com>
CC:	Dmitry Torokhov <dtor@...l.ru>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH V2 2/2] Input: misc: introduce palmas-pwrbutton

On 08/21/2014 12:37 PM, Menon, Nishanth wrote:
> On 12:32-20140821, Murphy, Dan wrote:
>> On 08/21/2014 12:19 PM, Menon, Nishanth wrote:
>>> On 08/21/2014 11:59 AM, Murphy, Dan wrote:
>>> [...]
>>> Ooops.. missed answering one addition statement:
>>>
>>>>> +	of_property_read_u32(np, "ti,palmas-long-press-seconds", &val);
>>>>
>>>> Probably should check the return to make sure the value exists and that is is
>>>> within an expected range.
>>> It is an optional parameter and may not exist in dt. when it does
>>> exist, the logic tries to do a best match (this is the for loop in the
>>> logic just below).
>>>
>>
>> The issue is val might be returned as a negative which will then proceed to
>> set the config->long_press_time_val to the lowest time value which then overrides
>> your initial setting of config->long_press_time_val = ARRAY_SIZE(lpk_times) - 1;
>>
> 
> Does the following as a replacement look OK? if yes, I can incorporate
> as part of v3 of this series.
> /**
>  * palmas_pwron_params_ofinit() - device tree parameter parser
>  * @dev:	palmas button device
>  * @config:	configuration params that this fills up
>  */
> static void palmas_pwron_params_ofinit(struct device *dev,
> 				       struct palmas_pwron_config *config)
> {
> 	struct device_node *np;
> 	u32 val;
> 	int i, ret;
> 	u8 lpk_times[] = { 6, 8, 10, 12 };
> 	int pwr_on_deb_ms[] = { 15, 100, 500, 1000 };
> 
> 	/* Handle cases where device node based configuration is not present */
> 	if (!of_have_populated_dt())
> 		return;
> 	np = of_node_get(dev->of_node);
> 	if (!np)
> 		return;
> 
> 	/* Default config parameters - least debounce, max long key press */
> 	config->pwron_debounce_val = 0;

And you can drop this as this value is set to zero in the probe when initialized.

> 	config->long_press_time_val = ARRAY_SIZE(lpk_times) - 1;

I would move this up to just before checking the dt.  Then they are defaulted
properly or move these to the probe.  Otherwise defaults are not set.

> 
> 	ret = of_property_read_u32(np, "ti,palmas-long-press-seconds", &val);
> 	if (ret)
> 		goto skip_lpk;
> 	for (i = 0; i < ARRAY_SIZE(lpk_times); i++) {
> 		if (val <= lpk_times[i]) {
> 			config->long_press_time_val = i;
> 			break;
> 		}
> 	}
> 
> skip_lpk:
> 	ret = of_property_read_u32(np, "ti,palmas-pwron-debounce-milli-seconds",
> 				   &val);
> 	if (ret)
> 		goto skip_debounce;
> 	for (i = 0; i < ARRAY_SIZE(pwr_on_deb_ms); i++) {
> 		if (val <= pwr_on_deb_ms[i]) {
> 			config->pwron_debounce_val = i;
> 			break;
> 		}
> 	}
> 
> skip_debounce:
> 	dev_info(dev, "h/w controlled shutdown duration=%d seconds\n",
> 		 lpk_times[config->long_press_time_val]);
> 
> 	of_node_put(np);
> }
> 


-- 
------------------
Dan Murphy
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