[PATCH 1/3] input: tsc2007: Add pre-calibration, flipping and rotation

From: Marek Belisko
Date: Tue Sep 30 2014 - 16:19:04 EST

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This patch adds new parameters that allow to address typical hardware
design differences: touch screens may be wired or oriented differently
(portrait or landscape). And usually the active area of the touch is a
little larger than the active area of the LCD. This results in the touch
coordinates that have some significant deviation from LCD coordinates.
Usually this is addressed in user space by a calibration tool (e.g. tslib
or xinput-calibrator) but some systems don't have these tools or require
that the screen is already roughly calibrated (e.g. Replicant) to operate
the device until a better calibration can be done. And, some systems
react very strangely if the touch event stream reports coordinates
outside of the active area.

This makes it necessry to be able to configure:
1. swapping x and y wires (coordinate values)
2. flipping of x (left - right) or y (top - bottom) or even both
3. define an active area so that an uncalibrated screen already
roughly matches the LCD to be useful.
4. clip reported coordinates to the active area.

If none of the new parameters is defined (in DT) or set in a board file,
the driver behaves the same as without this patch.

Author (1&2): H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
Author (3&4): Paul Kocialkowski <contact@xxxxxxxx>

Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
drivers/input/touchscreen/tsc2007.c | 89 +++++++++++++++++++++++++++++++++++--
include/linux/i2c/tsc2007.h | 6 +++
2 files changed, 91 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 1bf9906..cc0cc3c 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -74,6 +74,12 @@ struct tsc2007 {

u16 model;
u16 x_plate_ohms;
+ bool swap_xy; /* swap x and y axis */
+ u16 min_x;
+ u16 min_y;
+ u16 min_rt;
+ u16 max_x;
+ u16 max_y;
u16 max_rt;
unsigned long poll_period;
int fuzzx;
@@ -193,11 +199,50 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
break;
}

- if (rt <= ts->max_rt) {
+ if (rt <= max(ts->min_rt, ts->max_rt)) {
dev_dbg(&ts->client->dev,
"DOWN point(%4d,%4d), pressure (%4u)\n",
tc.x, tc.y, rt);

+ if (ts->swap_xy) {
+ /* swap before applying the range limits */
+ u16 h = tc.x;
+
+ tc.x = tc.y;
+ tc.y = h;
+ }
+
+ /* flip and/or clip X */
+ if (ts->max_x < ts->min_x)
+ tc.x = (ts->min_x - tc.x) + ts->max_x;
+
+ if (tc.x > max(ts->min_x, ts->max_x))
+ tc.x = max(ts->min_x, ts->max_x);
+ else if (tc.x < min(ts->min_x, ts->max_x))
+ tc.x = min(ts->min_x, ts->max_x);
+
+ /* flip and/or clip Y */
+ if (ts->max_y < ts->min_y)
+ tc.y = (ts->min_y - tc.y) + ts->max_y;
+
+ if (tc.y > max(ts->min_y, ts->max_y))
+ tc.y = max(ts->min_y, ts->max_y);
+ else if (tc.y < min(ts->min_y, ts->max_y))
+ tc.y = min(ts->min_y, ts->max_y);
+
+ /* clip Z */
+ if (ts->max_rt < ts->min_rt)
+ rt = (ts->min_rt - rt) + ts->max_rt;
+
+ if (rt > max(ts->min_rt, ts->max_rt))
+ rt = max(ts->min_rt, ts->max_rt);
+ else if (rt < min(ts->min_rt, ts->max_rt))
+ rt = min(ts->min_rt, ts->max_rt);
+
+ dev_dbg(&ts->client->dev,
+ "shaped point(%4d,%4d), pressure (%4u)\n",
+ tc.x, tc.y, rt);
+
input_report_key(input, BTN_TOUCH, 1);
input_report_abs(input, ABS_X, tc.x);
input_report_abs(input, ABS_Y, tc.y);
@@ -299,6 +344,24 @@ static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
return -EINVAL;
}

+ ts->swap_xy = of_property_read_bool(np, "ti,swap-xy");
+
+ if (!of_property_read_u32(np, "ti,min-x", &val32))
+ ts->min_x = val32;
+ if (!of_property_read_u32(np, "ti,max-x", &val32))
+ ts->max_x = val32;
+ else
+ ts->max_x = MAX_12BIT;
+
+ if (!of_property_read_u32(np, "ti,min-y", &val32))
+ ts->min_y = val32;
+ if (!of_property_read_u32(np, "ti,max-y", &val32))
+ ts->max_y = val32;
+ else
+ ts->max_y = MAX_12BIT;
+
+ if (!of_property_read_u32(np, "ti,min-rt", &val32))
+ ts->min_rt = val32;
if (!of_property_read_u32(np, "ti,max-rt", &val32))
ts->max_rt = val32;
else
@@ -325,6 +388,16 @@ static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
return -EINVAL;
}

+ dev_dbg(&client->dev,
+ "min/max_x (%4d,%4d)\n",
+ ts->min_x, ts->max_x);
+ dev_dbg(&client->dev,
+ "min/max_y (%4d,%4d)\n",
+ ts->min_y, ts->max_y);
+ dev_dbg(&client->dev,
+ "min/max_rt (%4d,%4d)\n",
+ ts->min_rt, ts->max_rt);
+
ts->gpio = of_get_gpio(np, 0);
if (gpio_is_valid(ts->gpio))
ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
@@ -349,6 +422,12 @@ static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
{
ts->model = pdata->model;
ts->x_plate_ohms = pdata->x_plate_ohms;
+ ts->swap_xy = pdata->swap_xy;
+ ts->min_x = pdata->min_x ? : 0;
+ ts->min_y = pdata->min_y ? : 0;
+ ts->min_rt = pdata->min_rt ? : 0;
+ ts->max_x = pdata->max_x ? : MAX_12BIT;
+ ts->max_y = pdata->max_y ? : MAX_12BIT;
ts->max_rt = pdata->max_rt ? : MAX_12BIT;
ts->poll_period = pdata->poll_period ? : 1;
ts->get_pendown_state = pdata->get_pendown_state;
@@ -422,9 +501,11 @@ static int tsc2007_probe(struct i2c_client *client,
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

- input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
- input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
- input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
+ input_set_abs_params(input_dev, ABS_X, min(ts->min_x, ts->max_x),
+ max(ts->min_x, ts->max_x), ts->fuzzx, 0);
+ input_set_abs_params(input_dev, ABS_Y, min(ts->min_y, ts->max_y),
+ max(ts->min_y, ts->max_y), ts->fuzzy, 0);
+ input_set_abs_params(input_dev, ABS_PRESSURE, ts->min_rt, ts->max_rt,
ts->fuzzz, 0);

if (pdata) {
diff --git a/include/linux/i2c/tsc2007.h b/include/linux/i2c/tsc2007.h
index 4f35b6a..5ce7b79 100644
--- a/include/linux/i2c/tsc2007.h
+++ b/include/linux/i2c/tsc2007.h
@@ -6,6 +6,12 @@
struct tsc2007_platform_data {
u16 model; /* 2007. */
u16 x_plate_ohms; /* must be non-zero value */
+ bool swap_xy; /* swap x and y axis */
+ u16 min_x; /* min and max values to reported to user space */
+ u16 min_y;
+ u16 min_rt;
+ u16 max_x;
+ u16 max_y;
u16 max_rt; /* max. resistance above which samples are ignored */
unsigned long poll_period; /* time (in ms) between samples */
int fuzzx; /* fuzz factor for X, Y and pressure axes */
--
1.9.3

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Next message: Dan Murphy: "Re: [PATCH] regmap: Allow read_reg_mask to be 0"
Previous message: Marek Belisko: "[PATCH 3/3] arm: dts: omap3-gta04: Extend touchscreen configs"
In reply to: Marek Belisko: "[PATCH 3/3] arm: dts: omap3-gta04: Extend touchscreen configs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]