On 08/21/2015 03:47 AM, Michael Welling wrote: > On Thu, Aug 20, 2015 at 05:41:30PM +0530, Vignesh R wrote: >> >> >> On 08/19/2015 11:38 PM, Michael Welling wrote: >>> On Wed, Aug 12, 2015 at 01:44:22PM -0500, Michael Welling wrote: >>>> On Wed, Aug 12, 2015 at 11:56:36AM +0530, Vignesh R wrote: >>>>> Hi Michael, >>>>> >>>>> + Dmitry >>>>> >>>>> On 08/12/2015 12:15 AM, Michael Welling wrote: >>>>>> Adds a device tree parameter to set the open delay on the touchscreen >>>>>> conversion steps. Increasing this parameter helps the touch accuracy on >>>>>> some screens. >>>>>> >>>>>> Signed-off-by: Michael Welling <mwelling@xxxxxxxx> >>>>>> --- >>>>>> .../bindings/input/touchscreen/ti-tsc-adc.txt | 5 +++++ >>>>>> drivers/input/touchscreen/ti_am335x_tsc.c | 18 ++++++++++++++---- >>>>>> 2 files changed, 19 insertions(+), 4 deletions(-) >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt >>>>>> index b1163bf..cb11fda 100644 >>>>>> --- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt >>>>>> +++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt >>>>>> @@ -41,6 +41,11 @@ Optional properties: >>>>>> charge step, so this does in fact function as a >>>>>> hardware knob for adjusting the amount of "settling >>>>>> time". >>>>>> + ti,open-delay: Open delay applied to all touchscreen conversion steps. >>>>>> + The value corresponds to the number of ADC clock >>>>>> + cycles to wait after applying the step configuration >>>>>> + registers and before sending the start of ADC >>>>>> + conversion. Maximum value is 0x3FFFF. >>>>>> >>>>> >>>>> Since open-delay is per step, is it not better to allow specifying >>>>> open-delay per step like ti,chan-step-opendelay of adc? This will help >>>>> control open-delay for all the four wires. >>>> >>>> Do you see any reason why you would want a different delay for each step of >>>> the conversion on the same touchscreen? >> >> >> Sorry for the delay, >> >> I haven't seen different delays being used for different channels on >> 4-wire TSC ( not sure of 5-wire or 8 wire designs). Since this is DT >> change, I just wanted to make sure more flexibility is provided. >> >>>> >>>> The user would need to know the number of steps what each of the steps do. >>>> >> >> >> What I was thinking was making open-delay configurable per channel (one >> entry for X+, X-, Y+, Y-). >> >> For example, for a 4-wire TSC: >> ti,chan-open-delay = <0x30 0x100 0x20 0x10>; /* for X+, X-, Y+, Y- */ >> > > What about the readings for the pressure? Sorry, I was confused with channels and co-ordinate readouts. Each of X, Y and pressure(Z) readouts will correspond to certain tscadc steps. So, what I have in mind is: ti,open-delay = <0x30 0x100 0x20>; /* for X, Y, Z */ For Steps that represents X co-ordinate readouts set opendelay = 0x30. For Steps that correspond to Y co-ordinate readouts set opendelay = 0x100 and similarly for 0x20 for Z. This is will provide flexibility to configure open-delay independently for X, Y and Z -- Regards Vignesh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
