The open delay time has to be applied only on the first sample of the
X/Y coordinates because on the following samples the ADC channel is not
changed. Removing this time from the samples after the first one,
"ti,coordinate-readouts" greater than 1, decreases the total acquisition
time, allowing to increase the number of acquired coordinates in the time
unit.
Signed-off-by: Dario Binacchi <dariobin@xxxxxxxxx>
---
(no changes since v1)
drivers/input/touchscreen/ti_am335x_tsc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index cfc943423241..f4ef218bc1b8 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -126,7 +126,7 @@ static int titsc_config_wires(struct titsc *ts_dev)
static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
- int i;
+ int i, n;
int end_step, first_step, tsc_steps;
u32 stepenable;
@@ -151,9 +151,11 @@ static void titsc_step_config(struct titsc *ts_dev)
first_step = TOTAL_STEPS - tsc_steps;
/* Steps 16 to 16-coordinate_readouts is for X */
end_step = first_step + tsc_steps;
+ n = 0;
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),
+ n++ == 0 ? STEPCONFIG_OPENDLY : 0);
}
config = 0;
@@ -175,9 +177,11 @@ static void titsc_step_config(struct titsc *ts_dev)
/* 1 ... coordinate_readouts is for Y */
end_step = first_step + ts_dev->coordinate_readouts;
+ n = 0;
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),
+ n++ == 0 ? STEPCONFIG_OPENDLY : 0);
}
/* Make CHARGECONFIG same as IDLECONFIG */
--
2.17.1
