[PATCH v5 2/2] Input: msg2638 - Add support for msg2138 key events

Vincent Knecht
2022-11-16T18:18:12Z

Some devices with msg2138 have back/menu/home keys.
Add support for them.

Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org>
---
drivers/input/touchscreen/msg2638.c | 57 +++++++++++++++++++++++++++--
1 file changed, 53 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/msg2638.c b/drivers/input/touchscreen/msg2638.c
index 95b18563326a..a0f5e1ecd612 100644
--- a/drivers/input/touchscreen/msg2638.c
+++ b/drivers/input/touchscreen/msg2638.c
@@ -21,6 +21,7 @@
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
+#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

@@ -29,6 +30,8 @@
#define MSG2138_MAX_FINGERS 2
#define MSG2638_MAX_FINGERS 5

+#define MAX_BUTTONS 4
+
#define CHIP_ON_DELAY_MS 15
#define FIRMWARE_ON_DELAY_MS 50
#define RESET_DELAY_MIN_US 10000
@@ -72,6 +75,8 @@ struct msg2638_ts_data {
struct regulator_bulk_data supplies[2];
struct gpio_desc *reset_gpiod;
int max_fingers;
+ u32 keycodes[MAX_BUTTONS];
+ int num_keycodes;
};

static u8 msg2638_checksum(u8 *data, u32 length)
@@ -85,6 +90,18 @@ static u8 msg2638_checksum(u8 *data, u32 length)
return (u8)((-sum) & 0xFF);
}

+static void msg2138_report_keys(struct msg2638_ts_data *msg2638, u8 keys)
+{
+ int i;
+
+ /* keys can be 0x00 or 0xff when all keys have been released */
+ if (keys == 0xff)
+ keys = 0;
+
+ for (i = 0; i < msg2638->num_keycodes; ++i)
+ input_report_key(msg2638->input_dev, msg2638->keycodes[i], keys & BIT(i));
+}
+
static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
{
struct msg2638_ts_data *msg2638 = msg2638_handler;
@@ -121,9 +138,12 @@ static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
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)
+ /* Ignore non-pressed finger data, but check for key code */
+ if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF) {
+ if (p1->xy_hi == 0xFF && p1->y_low == 0xFF)
+ msg2138_report_keys(msg2638, p1->x_low);
goto report;
+ }

x = ((p0->xy_hi & 0xF0) << 4) | p0->x_low;
y = ((p0->xy_hi & 0x0F) << 8) | p0->y_low;
@@ -283,6 +303,7 @@ static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
struct device *dev = &msg2638->client->dev;
struct input_dev *input_dev;
int error;
+ int i;

input_dev = devm_input_allocate_device(dev);
if (!input_dev) {
@@ -299,6 +320,14 @@ static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
input_dev->open = msg2638_input_open;
input_dev->close = msg2638_input_close;

+ if (msg2638->num_keycodes) {
+ input_dev->keycode = msg2638->keycodes;
+ input_dev->keycodemax = msg2638->num_keycodes;
+ input_dev->keycodesize = sizeof(msg2638->keycodes[0]);
+ for (i = 0; i < msg2638->num_keycodes; i++)
+ input_set_capability(input_dev, EV_KEY, msg2638->keycodes[i]);
+ }
+
input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);

@@ -367,9 +396,23 @@ static int msg2638_ts_probe(struct i2c_client *client)
return error;
}

- error = msg2638_init_input_dev(msg2638);
+ msg2638->num_keycodes = fwnode_property_count_u32(dev->fwnode, "linux,keycodes");
+ if (msg2638->num_keycodes == -EINVAL) {
+ msg2638->num_keycodes = 0;
+ } else if (msg2638->num_keycodes < 0) {
+ dev_err(dev, "Unable to parse linux,keycodes property: %d\n",
+ msg2638->num_keycodes);
+ return msg2638->num_keycodes;
+ } else if (msg2638->num_keycodes > ARRAY_SIZE(msg2638->keycodes)) {
+ dev_warn(dev, "Found %d linux,keycodes but max is %ld, ignoring the rest\n",
+ msg2638->num_keycodes, ARRAY_SIZE(msg2638->keycodes));
+ msg2638->num_keycodes = ARRAY_SIZE(msg2638->keycodes);
+ }
+
+ error = fwnode_property_read_u32_array(dev->fwnode, "linux,keycodes",
+ msg2638->keycodes, msg2638->num_keycodes);
if (error) {
- dev_err(dev, "Failed to initialize input device: %d\n", error);
+ dev_err(dev, "Unable to read linux,keycodes values: %d\n", error);
return error;
}

@@ -382,6 +425,12 @@ static int msg2638_ts_probe(struct i2c_client *client)
return error;
}

+ error = msg2638_init_input_dev(msg2638);
+ if (error) {
+ dev_err(dev, "Failed to initialize input device: %d\n", error);
+ return error;
+ }
+
return 0;
}

--
2.38.1