Re: [v2] input: drv260x: Add TI drv260x haptics driver

From: Mark Rutland
Date: Tue Jul 29 2014 - 10:40:12 EST


On Tue, Jul 29, 2014 at 02:50:48PM +0100, Murphy, Dan wrote:
> Mark
>
> Thanks for the feedback
>
> On 07/29/2014 04:37 AM, Mark Rutland wrote:
> > On Mon, Jul 28, 2014 at 05:53:23PM +0100, Dan Murphy wrote:
> >> Add the TI drv260x haptics/vibrator driver.
> >> This device uses the input force feedback
> >> to produce a wave form to driver an
> >> ERM or LRA actuator device.
> >>
> >> The initial driver supports the devices
> >> real time playback mode. But the device
> >> has additional wave patterns in ROM.
> >>
> >> This functionality will be added in
> >> future patchsets.
> >>
> >> Product data sheet is located here:
> >> http://www.ti.com/product/drv2605
> >>
> >> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> >> ---
> >>
> >> v2 - Fixed binding doc and patch headline - https://patchwork.kernel.org/patch/4619641/
> >>
> >> .../devicetree/bindings/input/ti,drv260x.txt | 44 ++
> >> drivers/input/misc/Kconfig | 9 +
> >> drivers/input/misc/Makefile | 1 +
> >> drivers/input/misc/drv260x.c | 537 ++++++++++++++++++++
> >> include/dt-bindings/input/ti-drv260x.h | 30 ++
> >> include/linux/input/drv260x.h | 181 +++++++
> >> 6 files changed, 802 insertions(+)
> >> create mode 100644 Documentation/devicetree/bindings/input/ti,drv260x.txt
> >> create mode 100644 drivers/input/misc/drv260x.c
> >> create mode 100644 include/dt-bindings/input/ti-drv260x.h
> >> create mode 100644 include/linux/input/drv260x.h
> >>
> >> diff --git a/Documentation/devicetree/bindings/input/ti,drv260x.txt b/Documentation/devicetree/bindings/input/ti,drv260x.txt
> >> new file mode 100644
> >> index 0000000..930429b
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/input/ti,drv260x.txt
> >> @@ -0,0 +1,44 @@
> >> +Texas Instruments - drv260x Haptics driver family
> >> +
> >> +The drv260x family serial control bus communicates through I2C protocols
> >> +
> >> +Required properties:
> >> + - compatible - One of:
> >> + "ti,drv2604" - DRV2604
> >> + "ti,drv2605" - DRV2605
> >> + "ti,drv2605l" - DRV2605L
> >> + - reg - I2C slave address
> >> + - mode - Power up mode of the chip (defined in include/dt-bindings/input/ti-drv260x.h)
> >> + DRV260X_RTP_MODE - Real time playback mode
> >> + DRV260X_LRA_MODE - Linear Resonance Actuator mode (Piezoelectric)
> >> + DRV260X_ERM_MODE - Eccentric Rotating Mass mode (Rotary vibrator)
> >
> > What exactly are these, and why does the kernel not decide?
>
> The LRA and ERM are vibrator types. These are specific to the product and the kernel cannot decide.
> The kernel driver needs to be told what type of vibrator is connected. The driver then
> sets the voltages and other settings to drive the vibrator type safely. All vibrators are dumb and do not
> have IDs identifying themselves so there is no self discovery here.

I see. That makes sense, thanks for the description.

It might make more sense to call this "vibrator-type", rather than
"mode", but otherwise this should be ok.

In the past I've asked for strings rather than magic numbers, but I'll
leave that choice to you.

> RTP is not a vibrator type but just a mode you can place the device into. I can probably remove that
> and have the user space or driver take care of that setting.

Ok, that sounds good to me.

>
> >
> >> + - library_sel - Library to use at power up (defined in include/dt-bindings/input/ti-drv260x.h)
> >
> > Please s/_/-/ in all property names.
> >
> >> + DRV260X_LIB_A - Pre-programmed Library
> >> + DRV260X_LIB_B - Pre-programmed Library
> >> + DRV260X_LIB_C - Pre-programmed Library
> >> + DRV260X_LIB_D - Pre-programmed Library
> >> + DRV260X_LIB_E - Pre-programmed Library
> >> + DRV260X_LIB_F - Pre-programmed Library
> >
> > What exactly are these, and why does the kernel not decide?
> >
> >> +
> >> +Optional properties:
> >> + - enable-gpio - gpio pin to enable/disable the device.
> >> + - vib_rated_voltage - The rated voltage of the actuator. If this is not
> >> + set then the value will be defaulted to 0x90 in the
> >> + driver.
> >
> > What units is this in?
>
> Good catch I was thinking this when I was writing the documentation but forgot to add
> it. I will fix the formatting here and below as well.

Cheers.

Mark.
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