Commit 3a59684c authored by Brad Griffis's avatar Brad Griffis Committed by Dmitry Torokhov

Input: ti_am335x_tsc - interchange touchscreen and ADC steps

This patch makes the initial changes required to workaround TSC-false
pen-up interrupts. It is required to implement these changes in order to
remove udelay in the TSC interrupt handler and false pen-up events.  The
charge step is to be executed immediately after sampling X+. Hence TSC is
made to use higher numbered steps (steps 5 to 16 for 5 co-ordinate
readouts, 4 wire TSC configuration) and ADC to use lower ones. Further X
co-ordinate readouts must be the last to be sampled, thus co-ordinates are
sampled in the order Y-Z-X.
Signed-off-by: default avatarBrad Griffis <bgriffis@ti.com>
[vigneshr@ti.com: Ported the patch from v3.12 to v3.19rc1]
Signed-off-by: default avatarVignesh R <vigneshr@ti.com>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 448c7f38
......@@ -86,19 +86,18 @@ static void tiadc_step_config(struct iio_dev *indio_dev)
{
struct tiadc_device *adc_dev = iio_priv(indio_dev);
unsigned int stepconfig;
int i, steps;
int i, steps = 0;
/*
* There are 16 configurable steps and 8 analog input
* lines available which are shared between Touchscreen and ADC.
*
* Steps backwards i.e. from 16 towards 0 are used by ADC
* Steps forwards i.e. from 0 towards 16 are used by ADC
* depending on number of input lines needed.
* Channel would represent which analog input
* needs to be given to ADC to digitalize data.
*/
steps = TOTAL_STEPS - adc_dev->channels;
if (iio_buffer_enabled(indio_dev))
stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1
| STEPCONFIG_MODE_SWCNT;
......
......@@ -121,7 +121,7 @@ static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
int i;
int end_step;
int end_step, first_step, tsc_steps;
u32 stepenable;
config = STEPCONFIG_MODE_HWSYNC |
......@@ -140,9 +140,11 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}
/* 1 … coordinate_readouts is for X */
end_step = ts_dev->coordinate_readouts;
for (i = 0; i < end_step; i++) {
tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
first_step = TOTAL_STEPS - tsc_steps;
/* Steps 16 to 16-coordinate_readouts is for X */
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);
}
......@@ -164,9 +166,9 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}
/* coordinate_readouts … coordinate_readouts * 2 is for Y */
end_step = ts_dev->coordinate_readouts * 2;
for (i = ts_dev->coordinate_readouts; i < end_step; i++) {
/* 1 ... coordinate_readouts is for Y */
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);
}
......@@ -179,7 +181,7 @@ static void titsc_step_config(struct titsc *ts_dev)
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
/* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
/* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_yp |
ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
......@@ -194,8 +196,11 @@ static void titsc_step_config(struct titsc *ts_dev)
titsc_writel(ts_dev, REG_STEPDELAY(end_step),
STEPCONFIG_OPENDLY);
/* The steps1 … end and bit 0 for TS_Charge */
stepenable = (1 << (end_step + 2)) - 1;
/* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
stepenable = 1;
for (i = 0; i < tsc_steps; i++)
stepenable |= 1 << (first_step + i + 1);
ts_dev->step_mask = stepenable;
am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
}
......@@ -209,6 +214,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
unsigned int read, diff;
unsigned int i, channel;
unsigned int creads = ts_dev->coordinate_readouts;
unsigned int first_step = TOTAL_STEPS - (creads * 2 + 2);
*z1 = *z2 = 0;
if (fifocount % (creads * 2 + 2))
......@@ -226,7 +232,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
channel = (read & 0xf0000) >> 16;
read &= 0xfff;
if (channel < creads) {
if (channel > first_step + creads + 2) {
diff = abs(read - prev_val_x);
if (diff < prev_diff_x) {
prev_diff_x = diff;
......@@ -234,19 +240,19 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
}
prev_val_x = read;
} else if (channel < creads * 2) {
} else if (channel == first_step + creads + 1) {
*z1 = read;
} else if (channel == first_step + creads + 2) {
*z2 = read;
} else if (channel > first_step) {
diff = abs(read - prev_val_y);
if (diff < prev_diff_y) {
prev_diff_y = diff;
*y = read;
}
prev_val_y = read;
} else if (channel < creads * 2 + 1) {
*z1 = read;
} else if (channel < creads * 2 + 2) {
*z2 = read;
}
}
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment