The controller has a RESET pin which is usually controlled over
a GPIO line. If such a GPIO is provided, perform a RESET
during probe.
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
.../bindings/input/touchscreen/pixcir_i2c_ts.txt | 3 ++
drivers/input/touchscreen/pixcir_i2c_ts.c | 37 ++++++++++++++++++++--
include/linux/input/pixcir_ts.h | 1 +
3 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
index 6e55109..8eb240a 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
@@ -8,6 +8,9 @@ Required properties:
- touchscreen-size-x: horizontal resolution of touchscreen (in pixels)
- touchscreen-size-y: vertical resolution of touchscreen (in pixels)
+Optional properties:
+- reset-gpio: GPIO connected to the RESET line of the chip
+
Example:
i2c@00000000 {
diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
index 2c21071..80c956d 100644
--- a/drivers/input/touchscreen/pixcir_i2c_ts.c
+++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
@@ -51,6 +51,19 @@ struct pixcir_report_data {
struct pixcir_touch touches[PIXCIR_MAX_SLOTS];
};
+static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
+{
+ const struct pixcir_ts_platform_data *pdata = tsdata->pdata;
+
+ if (gpio_is_valid(pdata->gpio_reset)) {
+ gpio_set_value(pdata->gpio_reset, 1);
+ ndelay(100); /* datasheet section 1.2.3 says 80ns min. */
+ gpio_set_value(pdata->gpio_reset, 0);
+ /* wait for controller ready. 100ms guess. */
+ msleep(100);
+ }
+}
+
static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
struct pixcir_report_data *report)
{
@@ -428,7 +441,8 @@ static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
pdata->chip = *(const struct pixcir_i2c_chip_data *)match->data;
pdata->gpio_attb = of_get_named_gpio(np, "attb-gpio", 0);
- /* gpio_attb validity is checked in probe */
+ pdata->gpio_reset = of_get_named_gpio(np, "reset-gpio", 0);
+ /* gpio validity is checked in probe */
if (of_property_read_u32(np, "touchscreen-size-x", &pdata->x_max)) {
dev_err(dev, "Failed to get touchscreen-size-x property\n");
@@ -442,8 +456,9 @@ static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
}
pdata->y_max -= 1;
- dev_dbg(dev, "%s: x %d, y %d, gpio %d\n", __func__,
- pdata->x_max + 1, pdata->y_max + 1, pdata->gpio_attb);
+ dev_dbg(dev, "%s: x %d, y %d, ATTB gpio %d, RESET gpio %d\n", __func__,
+ pdata->x_max + 1, pdata->y_max + 1, pdata->gpio_attb,
+ pdata->gpio_reset);
return pdata;
}
@@ -481,6 +496,10 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
return -EINVAL;
}
+ /* RESET gpio is optional */
+ if (!gpio_is_valid(pdata->gpio_reset))
+ dev_info(dev, "Invalid gpio_reset in pdata\n");
+
if (!pdata->chip.max_fingers) {
dev_err(dev, "Invalid max_fingers in pdata\n");
return -EINVAL;
@@ -530,6 +549,16 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
input_set_drvdata(input, tsdata);
+ if (gpio_is_valid(pdata->gpio_reset)) {
+ error = devm_gpio_request_one(dev, pdata->gpio_reset,
+ GPIOF_OUT_INIT_LOW,
+ "pixcir_i2c_reset");
+ if (error) {
+ dev_err(dev, "Failed to request RESET gpio\n");
+ return error;
+ }
+ }
+
error = devm_gpio_request_one(dev, pdata->gpio_attb,
GPIOF_DIR_IN, "pixcir_i2c_attb");
if (error) {
@@ -545,6 +574,8 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
return error;
}
+ pixcir_reset(tsdata);
+
/* Always be in IDLE mode to save power, device supports auto wake */
error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
if (error) {
diff --git a/include/linux/input/pixcir_ts.h b/include/linux/input/pixcir_ts.h
index 7bae83b..5b204dd 100644
--- a/include/linux/input/pixcir_ts.h
+++ b/include/linux/input/pixcir_ts.h
@@ -58,6 +58,7 @@ struct pixcir_ts_platform_data {
int x_max;
int y_max;
int gpio_attb; /* GPIO connected to ATTB line */
+ int gpio_reset; /* GPIO to RESET line. Set to -1 if unused */
struct pixcir_i2c_chip_data chip;
};
--
2.1.4
--
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