msg2138 only supports 2 fingers presses, and needs different processing
since second finger press is encoded as a delta position wrt. first one
and the packet/touch_event structs are not the same as msg2638.
Add support for it by implementing distinct structs and irq handler.
Signed-off-by: Vincent Knecht <vincent.knecht@xxxxxxxxxx>
---
drivers/input/touchscreen/msg2638.c | 93 +++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
diff --git a/drivers/input/touchscreen/msg2638.c b/drivers/input/touchscreen/msg2638.c
index 222adedf78bf..73e1b4d550fb 100644
--- a/drivers/input/touchscreen/msg2638.c
+++ b/drivers/input/touchscreen/msg2638.c
@@ -26,6 +26,7 @@
#define MODE_DATA_RAW 0x5A
+#define MSG2138_MAX_FINGERS 2
#define MSG2638_MAX_FINGERS 5
#define CHIP_ON_DELAY_MS 15
@@ -38,6 +39,18 @@ struct msg_chip_data {
unsigned int max_fingers;
};
+struct msg2138_packet {
+ u8 xy_hi; /* higher bits of x and y coordinates */
+ u8 x_low;
+ u8 y_low;
+};
+
+struct msg2138_touch_event {
+ u8 magic;
+ struct msg2138_packet pkt[MSG2138_MAX_FINGERS];
+ u8 checksum;
+};
+
struct msg2638_packet {
u8 xy_hi; /* higher bits of x and y coordinates */
u8 x_low;
@@ -72,6 +85,80 @@ static u8 msg2638_checksum(u8 *data, u32 length)
return (u8)((-sum) & 0xFF);
}
+static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
+{
+ struct msg2638_ts_data *msg2638 = msg2638_handler;
+ struct i2c_client *client = msg2638->client;
+ struct input_dev *input = msg2638->input_dev;
+ struct msg2138_touch_event touch_event;
+ u32 len = sizeof(touch_event);
+ struct i2c_msg msg[] = {
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = sizeof(touch_event),
+ .buf = (u8 *)&touch_event,
+ },
+ };
+ struct msg2138_packet *p0, *p1;
+ u16 x, y, delta_x, delta_y;
+ int ret;
+
+ ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+ if (ret != ARRAY_SIZE(msg)) {
+ dev_err(&client->dev,
+ "Failed I2C transfer in irq handler: %d\n",
+ ret < 0 ? ret : -EIO);
+ goto out;
+ }
+
+ if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
+ touch_event.checksum) {
+ dev_err(&client->dev, "Failed checksum!\n");
+ goto out;
+ }
+
+ p0 = &touch_event.pkt[0];
+ p1 = &touch_event.pkt[1];
+
+ /* Ignore non-pressed finger data */
+ if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF)
+ goto report;
+
+ x = (((p0->xy_hi & 0xF0) << 4) | p0->x_low);
+ y = (((p0->xy_hi & 0x0F) << 8) | p0->y_low);
+
+ input_mt_slot(input, 0);
+ input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(input, &msg2638->prop, x, y, true);
+
+ /* Ignore non-pressed finger data */
+ if (p1->xy_hi == 0xFF && p1->x_low == 0xFF && p1->y_low == 0xFF)
+ goto report;
+
+ /* Second finger is reported as a delta position */
+ delta_x = (((p1->xy_hi & 0xF0) << 4) | p1->x_low);
+ delta_y = (((p1->xy_hi & 0x0F) << 8) | p1->y_low);
+
+ /* Ignore second finger if both deltas equal 0 */
+ if (delta_x == 0 && delta_y == 0)
+ goto report;
+
+ x += delta_x;
+ y += delta_y;
+
+ input_mt_slot(input, 1);
+ input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(input, &msg2638->prop, x, y, true);
+
+report:
+ input_mt_sync_frame(msg2638->input_dev);
+ input_sync(msg2638->input_dev);
+
+out:
+ return IRQ_HANDLED;
+}
+
static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)
{
struct msg2638_ts_data *msg2638 = msg2638_handler;
@@ -331,12 +418,18 @@ static int __maybe_unused msg2638_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);
+static const struct msg_chip_data msg2138_data = {
+ .irq_handler = msg2138_ts_irq_handler,
+ .max_fingers = MSG2138_MAX_FINGERS,
+};
+
static const struct msg_chip_data msg2638_data = {
.irq_handler = msg2638_ts_irq_handler,
.max_fingers = MSG2638_MAX_FINGERS,
};
static const struct of_device_id msg2638_of_match[] = {
+ { .compatible = "mstar,msg2138", .data = &msg2138_data },
{ .compatible = "mstar,msg2638", .data = &msg2638_data },
{ }
};
--
2.38.1
