Re: [PATCH v4 01/24] input: Add ff-memless-next module

From: Michal Malý
Date: Tue May 20 2014 - 20:08:24 EST


On Tuesday 20 of May 2014 19:45:44 simon@xxxxxxxxxxxxx wrote:
> >> Regarding the question of emulated vs. real effects, can we extend the
> >> API
> >> so that applications can know which effects are really supported, and
> >> enable/disable emulation somehow?
> >
> > I suppose that a few extra flags (FF_PERIODIC_EMULATED etc.) defined in
> > "uapi/linux/input.h" should suffice.
>
> The only problem is that we probably want to maintain backward
> compatibility so that older apps still see 'PERIODIC' (even though it is
> emulated).
> --
> #define FF_RUMBLE 0x50
> #define FF_PERIODIC 0x51
> #define FF_CONSTANT 0x52
> #define FF_SPRING 0x53
> #define FF_FRICTION 0x54
> #define FF_DAMPER 0x55
> #define FF_INERTIA 0x56
> #define FF_RAMP 0x57
> --
>
> Do we therefore have to list extra items in our capabilities?
> --
> static const signed short lg4ff_wheel_effects[] = {
> FF_CONSTANT,
> FF_PERIODIC,
> FF_PERIODIC_NOT_EMULATED,
> FF_AUTOCENTER,
> -1
> };
> --
>
> Simon

Actually I was thinking something like this:

"input.h"
#define FF_DAMPER 0x55
#define FF_INERTIA 0x56
#define FF_RAMP 0x57
+# define FF_PERIODIC_EMULATED 0x58
+# define FF_RUMBLE_EMULATED 0x59

and

in the future "library-like" reimplementation of MLNX:
#define EMULATE_PERIODIC BIT(0)
#define EMULATE_RUMBLE BIT(1)

kfflib_init(..., EMULATE_PERIODIC | EMULATE_RUMBLE);
for full emulation.

Michal


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