Touch window tracking allows to pre-set a sub-window in the
touchscreen area such that any touch position that is outside
the sub-window is discarded.
Signed-off-by: Leif Middelschulte <leif.middelschulte@xxxxxxxxxxxxx>
---
drivers/input/touchscreen/stmpe-ts.c | 96 +++++++++++++++++++++++++++-
1 file changed, 94 insertions(+), 2 deletions(-)
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
index cf9c9aa39f6e..6917237bd6c6 100644
--- a/drivers/input/touchscreen/stmpe-ts.c
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -19,6 +19,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/input.h>
+#include <linux/input/touchscreen.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
@@ -35,6 +36,10 @@
#define STMPE_REG_FIFO_TH 0x4A
#define STMPE_REG_FIFO_STA 0x4B
#define STMPE_REG_FIFO_SIZE 0x4C
+#define STMPE_REG_WDW_TR_X 0x42
+#define STMPE_REG_WDW_TR_Y 0x44
+#define STMPE_REG_WDW_BL_X 0x46
+#define STMPE_REG_WDW_BL_Y 0x48
#define STMPE_REG_TSC_DATA_XYZ 0x52
#define STMPE_REG_TSC_FRACTION_Z 0x56
#define STMPE_REG_TSC_I_DRIVE 0x58
@@ -82,6 +87,22 @@ struct stmpe_touch {
u8 settling;
u8 fraction_z;
u8 i_drive;
+ struct {
+ struct {
+ u16 x;
+ u16 y;
+ } top_right;
+ struct {
+ u16 x;
+ u16 y;
+ } bottom_left;
+ } wdw;
+ bool wdw_from_dt;
+ struct touchscreen_properties props;
+ struct {
+ u32 x;
+ u32 y;
+ } min;
};
static int __stmpe_reset_fifo(struct stmpe *stmpe)
@@ -128,6 +149,27 @@ static void stmpe_work(struct work_struct *work)
input_sync(ts->idev);
}
+static void stmpe_update_range_values(struct stmpe_touch *ts)
+{
+ u8 data_set[2];
+ /*
+ * Calculate max_x and max_y based on window size configuration read
+ * from touchscreen controller
+ */
+ stmpe_block_read(ts->stmpe, STMPE_REG_WDW_TR_X, 2, data_set);
+ ts->wdw.top_right.x = (data_set[0] << 8) | (data_set[1]);
+ stmpe_block_read(ts->stmpe, STMPE_REG_WDW_TR_Y, 2, data_set);
+ ts->wdw.top_right.y = (data_set[0] << 8) | (data_set[1]);
+ stmpe_block_read(ts->stmpe, STMPE_REG_WDW_BL_X, 2, data_set);
+ ts->wdw.bottom_left.x = (data_set[0] << 8) | (data_set[1]);
+ stmpe_block_read(ts->stmpe, STMPE_REG_WDW_BL_Y, 2, data_set);
+ ts->wdw.bottom_left.y = (data_set[0] << 8) | (data_set[1]);
+ ts->min.x = ts->wdw.bottom_left.x;
+ ts->min.y = ts->wdw.bottom_left.y;
+ ts->props.max_x = ts->wdw.top_right.x;
+ ts->props.max_y = ts->wdw.top_right.y;
+}
+
static irqreturn_t stmpe_ts_handler(int irq, void *data)
{
u8 data_set[4];
@@ -212,6 +254,44 @@ static int stmpe_init_hw(struct stmpe_touch *ts)
return ret;
}
+ if (ts->wdw_from_dt) {
+ u8 data_set[2];
+
+ data_set[0] = ts->wdw.top_right.x >> 8;
+ data_set[1] = ts->wdw.top_right.x;
+ ret = stmpe_block_write(ts->stmpe,
+ STMPE_REG_WDW_TR_X, 2, data_set);
+ if (ret) {
+ dev_err(dev, "Could not configure touchscreen window's top right x value\n");
+ return ret;
+ }
+ data_set[0] = ts->wdw.top_right.y >> 8;
+ data_set[1] = ts->wdw.top_right.y;
+ ret = stmpe_block_write(ts->stmpe,
+ STMPE_REG_WDW_TR_Y, 2, data_set);
+ if (ret) {
+ dev_err(dev, "Could not configure touchscreen window's top right y value\n");
+ return ret;
+ }
+ data_set[0] = ts->wdw.bottom_left.x >> 8;
+ data_set[1] = ts->wdw.bottom_left.x;
+ ret = stmpe_block_write(ts->stmpe,
+ STMPE_REG_WDW_BL_X, 2, data_set);
+ if (ret) {
+ dev_err(dev, "Could not configure touchscreen window's bottom left x value\n");
+ return ret;
+ }
+ data_set[0] = ts->wdw.bottom_left.y >> 8;
+ data_set[1] = ts->wdw.bottom_left.y;
+ ret = stmpe_block_write(ts->stmpe,
+ STMPE_REG_WDW_BL_Y, 2, data_set);
+ if (ret) {
+ dev_err(dev, "Could not configure touchscreen window's bottom left y value\n");
+ return ret;
+ }
+ }
+ stmpe_update_range_values(ts);
+
ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive));
if (ret) {
@@ -264,6 +344,7 @@ static void stmpe_ts_get_platform_info(struct platform_device *pdev,
{
struct device_node *np = pdev->dev.of_node;
u32 val;
+ u16 wdw[4];
if (np) {
if (!of_property_read_u32(np, "st,sample-time", &val))
@@ -284,6 +365,15 @@ static void stmpe_ts_get_platform_info(struct platform_device *pdev,
ts->fraction_z = val;
if (!of_property_read_u32(np, "st,i-drive", &val))
ts->i_drive = val;
+ if (!of_property_read_u16_array(np, "st,window-tracking",
+ wdw, 4)) {
+ ts->wdw.top_right.x = wdw[0] & XY_MASK;
+ ts->wdw.top_right.y = wdw[1] & XY_MASK;
+ ts->wdw.bottom_left.x = wdw[2] & XY_MASK;
+ ts->wdw.bottom_left.y = wdw[3] & XY_MASK;
+ ts->wdw_from_dt = true;
+ }
+ touchscreen_parse_properties(ts->idev, false, &ts->props);
}
}
@@ -338,8 +428,10 @@ static int stmpe_input_probe(struct platform_device *pdev)
input_set_drvdata(idev, ts);
input_set_capability(idev, EV_KEY, BTN_TOUCH);
- input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
- input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
+ input_set_abs_params(idev,
+ ABS_X, ts->min.x, ts->props.max_x, 0, 0);
+ input_set_abs_params(idev,
+ ABS_Y, ts->min.y, ts->props.max_y, 0, 0);
input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
error = input_register_device(idev);
--
2.21.0
