lkml.org 
[lkml]   [2019]   [Feb]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v4 4/4] gnss: add driver for mediatek receivers
Date

On Thu 14 Feb 2019 at 10:12, Johan Hovold <johan@kernel.org> wrote:

> On Thu, Feb 14, 2019 at 11:00:19AM +0100, Corentin Labbe wrote:
>> On Wed, Feb 13, 2019 at 04:09:29PM +0100, Loys Ollivier wrote:
>> > Add driver for serial-connected Mediatek-based GNSS receivers.
>> >
>> > These devices typically boot transmitting vendor specific NMEA output
>> > sequences. The serial port bit rate is read from the device tree
>> > "current-speed".
>> >
>> > Note that the driver uses the generic GNSS serial implementation and
>> > therefore essentially only manages power abstracted into three power
>> > states: ACTIVE, STANDBY, and OFF.
>> >
>> > For mediatek receivers with a main supply and no enable-gpios, this simply
>> > means that the main supply is disabled in STANDBY and OFF (the optional
>> > backup supply is kept enabled while the driver is bound).
>> >
>> > Note that the timepulse-support is left unimplemented.
>> >
>> > Signed-off-by: Loys Ollivier <lollivier@baylibre.com>
>
>> > +static int mtk_set_active(struct gnss_serial *gserial)
>> > +{
>> > + struct mtk_data *data = gnss_serial_get_drvdata(gserial);
>> > + int ret;
>> > +
>> > + ret = regulator_enable(data->vcc);
>> > + if (ret)
>> > + return ret;
>> > +
>> > + return 0;
>> > +}
>>
>> Hello
>>
>> This could be simplified to return regulator_enable(data->vcc);
>
> Indeed, but I prefer this style which clearly separates the error path
> from the success path while making the success return value explicit.
>

It respects the coding style/standard and I prefer the original version.
It's also easier to debug if you want to add extra code on error.

>> Furthermore, after this simplification, the function seems useless.
>
> Why do you think so? You still need to retrieve the regulator from the
> driver data. Sure, this could be folded into mtk_set_power(), but that
> would be less ideal if there are more resources that need to be managed
> (e.g. an external lna supply).

I would be in favor to keep mtk_set_active. It clearly shows when the
regulator is enabled.
It also seems logic to have an enable/standby function in the driver.
Even if those are trivial (for now).

>
> Thanks,
> Johan


--
-L

\
 
 \ /
  Last update: 2019-02-15 13:26    [W:0.039 / U:8.752 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site