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. > - child "adc" > ti,chan-step-opendelay: List of open delays for each channel of > diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c > index 191a1b8..37a9729 100644 > --- a/drivers/input/touchscreen/ti_am335x_tsc.c > +++ b/drivers/input/touchscreen/ti_am335x_tsc.c > @@ -54,6 +54,7 @@ struct titsc { > u32 inp_xp, inp_xn, inp_yp, inp_yn; > u32 step_mask; > u32 charge_delay; > + u32 open_delay; > }; > > static unsigned int titsc_readl(struct titsc *ts, unsigned int reg) > @@ -148,7 +149,7 @@ static void titsc_step_config(struct titsc *ts_dev) > end_step = first_step + tsc_steps; > for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) { > titsc_writel(ts_dev, REG_STEPCONFIG(i), config); > - titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY); > + titsc_writel(ts_dev, REG_STEPDELAY(i), ts_dev->open_delay); > } > > config = 0; > @@ -172,7 +173,7 @@ static void titsc_step_config(struct titsc *ts_dev) > end_step = first_step + ts_dev->coordinate_readouts; > for (i = first_step; i < end_step; i++) { > titsc_writel(ts_dev, REG_STEPCONFIG(i), config); > - titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY); > + titsc_writel(ts_dev, REG_STEPDELAY(i), ts_dev->open_delay); > } > > /* Make CHARGECONFIG same as IDLECONFIG */ > @@ -188,13 +189,13 @@ static void titsc_step_config(struct titsc *ts_dev) > STEPCONFIG_INP(ts_dev->inp_xp); > titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config); > titsc_writel(ts_dev, REG_STEPDELAY(end_step), > - STEPCONFIG_OPENDLY); > + ts_dev->open_delay); > > end_step++; > config |= STEPCONFIG_INP(ts_dev->inp_yn); > titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config); > titsc_writel(ts_dev, REG_STEPDELAY(end_step), > - STEPCONFIG_OPENDLY); > + ts_dev->open_delay); > > /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */ > stepenable = 1; > @@ -392,6 +393,15 @@ static int titsc_parse_dt(struct platform_device *pdev, > dev_warn(&pdev->dev, "ti,charge-delay not specified\n"); > } > > + err = of_property_read_u32(node, "ti,open-delay", > + &ts_dev->open_delay); > + /* > + * If ti,open-delay value is not specified, then use > + * STEPCONFIG_OPENDLY as the default value. > + */ > + if (err < 0) > + ts_dev->open_delay = STEPCONFIG_OPENDLY; > + > return of_property_read_u32_array(node, "ti,wire-config", > ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp)); > } > -- 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