[PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[Dmitry Mastykin]

Some devices with a goodix touchscreen have more then 1 capacitive
touch-key. This commit replaces the current support for a single
touch-key, which ignored the reported key-code. With support for
up to 7 touch-keys, based upon checking the key-code which is
post-fixed to any reported touch-data.

KEY_LEFTMETA is assigned to the first touch-key (it will still be
the default keycode for devices with a single touch-key).
KEY_F1, KEY_F2... are assigned as default keycode for the other
touch-keys.

This commit also add supports for keycode remapping, so that
systemd-udev's hwdb can be used to remap the codes to send
keycodes to match the icons on the buttons for devices with more
then 1 touch-key.

Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
---
Changes in v3:
- Refactor to get rid of magic "2" in goodix_ts_read_input_report()

Changes in v2:
- Improve commit message
---
 drivers/input/touchscreen/goodix.c | 60 +++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 13 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index adb9b92..04b5c7b 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -38,6 +38,7 @@
 #define GOODIX_CONTACT_SIZE		8
 #define GOODIX_MAX_CONTACT_SIZE		9
 #define GOODIX_MAX_CONTACTS		10
+#define GOODIX_MAX_KEYS			7
 
 #define GOODIX_CONFIG_MIN_LENGTH	186
 #define GOODIX_CONFIG_911_LENGTH	186
@@ -55,6 +56,7 @@
 #define GOODIX_REG_ID			0x8140
 
 #define GOODIX_BUFFER_STATUS_READY	BIT(7)
+#define GOODIX_HAVE_KEY			BIT(4)
 #define GOODIX_BUFFER_STATUS_TIMEOUT	20
 
 #define RESOLUTION_LOC		1
@@ -100,6 +102,7 @@ struct goodix_ts_data {
 	enum goodix_irq_pin_access_method irq_pin_access_method;
 	unsigned int contact_size;
 	u8 config[GOODIX_CONFIG_MAX_LENGTH];
+	unsigned short keymap[GOODIX_MAX_KEYS];
 };
 
 static int goodix_check_cfg_8(struct goodix_ts_data *ts,
@@ -277,6 +280,13 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 	unsigned long max_timeout;
 	int touch_num;
 	int error;
+	u16 addr = GOODIX_READ_COOR_ADDR;
+	/*
+	 * We are going to read 1-byte header,
+	 * ts->contact_size * max(1, touch_num) bytes of coordinates
+	 * and 1-byte footer which contains the touch-key code.
+	 */
+	const int header_contact_keycode_size = 1 + ts->contact_size + 1;
 
 	/*
 	 * The 'buffer status' bit, which indicates that the data is valid, is
@@ -285,8 +295,8 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 	 */
 	max_timeout = jiffies + msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
 	do {
-		error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR,
-					data, ts->contact_size + 1);
+		error = goodix_i2c_read(ts->client, addr, data,
+					header_contact_keycode_size);
 		if (error) {
 			dev_err(&ts->client->dev, "I2C transfer error: %d\n",
 					error);
@@ -299,11 +309,10 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 				return -EPROTO;
 
 			if (touch_num > 1) {
-				data += 1 + ts->contact_size;
+				addr += header_contact_keycode_size;
+				data += header_contact_keycode_size;
 				error = goodix_i2c_read(ts->client,
-						GOODIX_READ_COOR_ADDR +
-							1 + ts->contact_size,
-						data,
+						addr, data,
 						ts->contact_size *
 							(touch_num - 1));
 				if (error)
@@ -353,6 +362,23 @@ static void goodix_ts_report_touch_9b(struct goodix_ts_data *ts, u8 *coor_data)
 	input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
 }
 
+static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
+{
+	int touch_num;
+	u8 key_value;
+	int i;
+
+	if (data[0] & GOODIX_HAVE_KEY) {
+		touch_num = data[0] & 0x0f;
+		key_value = data[1 + ts->contact_size * touch_num];
+		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
+			if (key_value & (1 << i))
+				input_report_key(ts->input_dev, ts->keymap[i], 1);
+	} else
+		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
+			input_report_key(ts->input_dev, ts->keymap[i], 0);
+}
+
 /**
  * goodix_process_events - Process incoming events
  *
@@ -363,7 +389,7 @@ static void goodix_ts_report_touch_9b(struct goodix_ts_data *ts, u8 *coor_data)
  */
 static void goodix_process_events(struct goodix_ts_data *ts)
 {
-	u8  point_data[1 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
+	u8  point_data[2 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
 	int touch_num;
 	int i;
 
@@ -371,11 +397,7 @@ static void goodix_process_events(struct goodix_ts_data *ts)
 	if (touch_num < 0)
 		return;
 
-	/*
-	 * Bit 4 of the first byte reports the status of the capacitive
-	 * Windows/Home button.
-	 */
-	input_report_key(ts->input_dev, KEY_LEFTMETA, point_data[0] & BIT(4));
+	goodix_ts_report_key(ts, point_data);
 
 	for (i = 0; i < touch_num; i++)
 		if (ts->contact_size == 9)
@@ -961,6 +983,7 @@ static int goodix_i2c_test(struct i2c_client *client)
 static int goodix_configure_dev(struct goodix_ts_data *ts)
 {
 	int error;
+	int i;
 
 	ts->int_trigger_type = GOODIX_INT_TRIGGER;
 	ts->max_touch_num = GOODIX_MAX_CONTACTS;
@@ -978,8 +1001,19 @@ static int goodix_configure_dev(struct goodix_ts_data *ts)
 	ts->input_dev->id.product = ts->id;
 	ts->input_dev->id.version = ts->version;
 
+	ts->input_dev->keycode = ts->keymap;
+	ts->input_dev->keycodesize = sizeof(ts->keymap[0]);
+	ts->input_dev->keycodemax = GOODIX_MAX_KEYS;
+
 	/* Capacitive Windows/Home button on some devices */
-	input_set_capability(ts->input_dev, EV_KEY, KEY_LEFTMETA);
+	for (i = 0; i < GOODIX_MAX_KEYS; ++i) {
+		if (i == 0)
+			ts->keymap[i] = KEY_LEFTMETA;
+		else
+			ts->keymap[i] = KEY_F1 + (i - 1);
+
+		input_set_capability(ts->input_dev, EV_KEY, ts->keymap[i]);
+	}
 
 	input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_X);
 	input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_Y);
-- 
2.23.0

[PATCH v3 2/2] Input: goodix - Fix spurious key release events

[Dmitry Mastykin]

The goodix panel sends spurious interrupts after a 'finger up' event,
which always cause a timeout.
We were exiting the interrupt handler by reporting touch_num == 0, but
this was still processed as valid and caused the code to use the
uninitialised point_data, creating spurious key release events.

Report an error from the interrupt handler so as to avoid processing
invalid point_data further.

Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
---
Changes in v3:
- Improve commit message

Changes in v2:
- Improve commit message
---
 drivers/input/touchscreen/goodix.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 04b5c7b..cc965fe 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -329,7 +329,7 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 	 * The Goodix panel will send spurious interrupts after a
 	 * 'finger up' event, which will always cause a timeout.
 	 */
-	return 0;
+	return -ENOMSG;
 }
 
 static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)
-- 
2.23.0

Re: [PATCH v3 2/2] Input: goodix - Fix spurious key release events

[Bastien Nocera]

On Mon, 2020-03-16 at 10:53 +0300, Dmitry Mastykin wrote:
> The goodix panel sends spurious interrupts after a 'finger up' event,
> which always cause a timeout.
> We were exiting the interrupt handler by reporting touch_num == 0,
> but
> this was still processed as valid and caused the code to use the
> uninitialised point_data, creating spurious key release events.
> 
> Report an error from the interrupt handler so as to avoid processing
> invalid point_data further.
> 
> Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>

LGTM

Reviewed-by: Bastien Nocera <hadess@hadess.net>

> ---
> Changes in v3:
> - Improve commit message
> 
> Changes in v2:
> - Improve commit message
> ---
>  drivers/input/touchscreen/goodix.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index 04b5c7b..cc965fe 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -329,7 +329,7 @@ static int goodix_ts_read_input_report(struct
> goodix_ts_data *ts, u8 *data)
>  	 * The Goodix panel will send spurious interrupts after a
>  	 * 'finger up' event, which will always cause a timeout.
>  	 */
> -	return 0;
> +	return -ENOMSG;
>  }
>  
>  static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8
> *coor_data)

Re: [PATCH v3 2/2] Input: goodix - Fix spurious key release events

[Dmitry Torokhov]

On Mon, Mar 16, 2020 at 10:53:05AM +0300, Dmitry Mastykin wrote:
> The goodix panel sends spurious interrupts after a 'finger up' event,
> which always cause a timeout.
> We were exiting the interrupt handler by reporting touch_num == 0, but
> this was still processed as valid and caused the code to use the
> uninitialised point_data, creating spurious key release events.
> 
> Report an error from the interrupt handler so as to avoid processing
> invalid point_data further.
> 
> Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>

Applied, thank you.

> ---
> Changes in v3:
> - Improve commit message
> 
> Changes in v2:
> - Improve commit message
> ---
>  drivers/input/touchscreen/goodix.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index 04b5c7b..cc965fe 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -329,7 +329,7 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
>  	 * The Goodix panel will send spurious interrupts after a
>  	 * 'finger up' event, which will always cause a timeout.
>  	 */
> -	return 0;
> +	return -ENOMSG;
>  }
>  
>  static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)
> -- 
> 2.23.0
> 

-- 
Dmitry

Re: [PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[Bastien Nocera]

On Mon, 2020-03-16 at 10:53 +0300, Dmitry Mastykin wrote:
> Some devices with a goodix touchscreen have more then 1 capacitive
> touch-key. This commit replaces the current support for a single
> touch-key, which ignored the reported key-code. With support for
> up to 7 touch-keys, based upon checking the key-code which is
> post-fixed to any reported touch-data.
> 
> KEY_LEFTMETA is assigned to the first touch-key (it will still be
> the default keycode for devices with a single touch-key).
> KEY_F1, KEY_F2... are assigned as default keycode for the other
> touch-keys.
> 
> This commit also add supports for keycode remapping, so that
> systemd-udev's hwdb can be used to remap the codes to send
> keycodes to match the icons on the buttons for devices with more
> then 1 touch-key.
> 
> Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>


LGTM

Reviewed-by: Bastien Nocera <hadess@hadess.net>

> ---
> Changes in v3:
> - Refactor to get rid of magic "2" in goodix_ts_read_input_report()
> 
> Changes in v2:
> - Improve commit message
> ---
>  drivers/input/touchscreen/goodix.c | 60 +++++++++++++++++++++++-----
> --
>  1 file changed, 47 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index adb9b92..04b5c7b 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -38,6 +38,7 @@
>  #define GOODIX_CONTACT_SIZE		8
>  #define GOODIX_MAX_CONTACT_SIZE		9
>  #define GOODIX_MAX_CONTACTS		10
> +#define GOODIX_MAX_KEYS			7
>  
>  #define GOODIX_CONFIG_MIN_LENGTH	186
>  #define GOODIX_CONFIG_911_LENGTH	186
> @@ -55,6 +56,7 @@
>  #define GOODIX_REG_ID			0x8140
>  
>  #define GOODIX_BUFFER_STATUS_READY	BIT(7)
> +#define GOODIX_HAVE_KEY			BIT(4)
>  #define GOODIX_BUFFER_STATUS_TIMEOUT	20
>  
>  #define RESOLUTION_LOC		1
> @@ -100,6 +102,7 @@ struct goodix_ts_data {
>  	enum goodix_irq_pin_access_method irq_pin_access_method;
>  	unsigned int contact_size;
>  	u8 config[GOODIX_CONFIG_MAX_LENGTH];
> +	unsigned short keymap[GOODIX_MAX_KEYS];
>  };
>  
>  static int goodix_check_cfg_8(struct goodix_ts_data *ts,
> @@ -277,6 +280,13 @@ static int goodix_ts_read_input_report(struct
> goodix_ts_data *ts, u8 *data)
>  	unsigned long max_timeout;
>  	int touch_num;
>  	int error;
> +	u16 addr = GOODIX_READ_COOR_ADDR;
> +	/*
> +	 * We are going to read 1-byte header,
> +	 * ts->contact_size * max(1, touch_num) bytes of coordinates
> +	 * and 1-byte footer which contains the touch-key code.
> +	 */
> +	const int header_contact_keycode_size = 1 + ts->contact_size +
> 1;
>  
>  	/*
>  	 * The 'buffer status' bit, which indicates that the data is
> valid, is
> @@ -285,8 +295,8 @@ static int goodix_ts_read_input_report(struct
> goodix_ts_data *ts, u8 *data)
>  	 */
>  	max_timeout = jiffies +
> msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
>  	do {
> -		error = goodix_i2c_read(ts->client,
> GOODIX_READ_COOR_ADDR,
> -					data, ts->contact_size + 1);
> +		error = goodix_i2c_read(ts->client, addr, data,
> +					header_contact_keycode_size);
>  		if (error) {
>  			dev_err(&ts->client->dev, "I2C transfer error:
> %d\n",
>  					error);
> @@ -299,11 +309,10 @@ static int goodix_ts_read_input_report(struct
> goodix_ts_data *ts, u8 *data)
>  				return -EPROTO;
>  
>  			if (touch_num > 1) {
> -				data += 1 + ts->contact_size;
> +				addr += header_contact_keycode_size;
> +				data += header_contact_keycode_size;
>  				error = goodix_i2c_read(ts->client,
> -						GOODIX_READ_COOR_ADDR +
> -							1 + ts-
> >contact_size,
> -						data,
> +						addr, data,
>  						ts->contact_size *
>  							(touch_num -
> 1));
>  				if (error)
> @@ -353,6 +362,23 @@ static void goodix_ts_report_touch_9b(struct
> goodix_ts_data *ts, u8 *coor_data)
>  	input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
>  }
>  
> +static void goodix_ts_report_key(struct goodix_ts_data *ts, u8
> *data)
> +{
> +	int touch_num;
> +	u8 key_value;
> +	int i;
> +
> +	if (data[0] & GOODIX_HAVE_KEY) {
> +		touch_num = data[0] & 0x0f;
> +		key_value = data[1 + ts->contact_size * touch_num];
> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> +			if (key_value & (1 << i))
> +				input_report_key(ts->input_dev, ts-
> >keymap[i], 1);
> +	} else
> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> +			input_report_key(ts->input_dev, ts->keymap[i],
> 0);
> +}
> +
>  /**
>   * goodix_process_events - Process incoming events
>   *
> @@ -363,7 +389,7 @@ static void goodix_ts_report_touch_9b(struct
> goodix_ts_data *ts, u8 *coor_data)
>   */
>  static void goodix_process_events(struct goodix_ts_data *ts)
>  {
> -	u8  point_data[1 + GOODIX_MAX_CONTACT_SIZE *
> GOODIX_MAX_CONTACTS];
> +	u8  point_data[2 + GOODIX_MAX_CONTACT_SIZE *
> GOODIX_MAX_CONTACTS];
>  	int touch_num;
>  	int i;
>  
> @@ -371,11 +397,7 @@ static void goodix_process_events(struct
> goodix_ts_data *ts)
>  	if (touch_num < 0)
>  		return;
>  
> -	/*
> -	 * Bit 4 of the first byte reports the status of the capacitive
> -	 * Windows/Home button.
> -	 */
> -	input_report_key(ts->input_dev, KEY_LEFTMETA, point_data[0] &
> BIT(4));
> +	goodix_ts_report_key(ts, point_data);
>  
>  	for (i = 0; i < touch_num; i++)
>  		if (ts->contact_size == 9)
> @@ -961,6 +983,7 @@ static int goodix_i2c_test(struct i2c_client
> *client)
>  static int goodix_configure_dev(struct goodix_ts_data *ts)
>  {
>  	int error;
> +	int i;
>  
>  	ts->int_trigger_type = GOODIX_INT_TRIGGER;
>  	ts->max_touch_num = GOODIX_MAX_CONTACTS;
> @@ -978,8 +1001,19 @@ static int goodix_configure_dev(struct
> goodix_ts_data *ts)
>  	ts->input_dev->id.product = ts->id;
>  	ts->input_dev->id.version = ts->version;
>  
> +	ts->input_dev->keycode = ts->keymap;
> +	ts->input_dev->keycodesize = sizeof(ts->keymap[0]);
> +	ts->input_dev->keycodemax = GOODIX_MAX_KEYS;
> +
>  	/* Capacitive Windows/Home button on some devices */
> -	input_set_capability(ts->input_dev, EV_KEY, KEY_LEFTMETA);
> +	for (i = 0; i < GOODIX_MAX_KEYS; ++i) {
> +		if (i == 0)
> +			ts->keymap[i] = KEY_LEFTMETA;
> +		else
> +			ts->keymap[i] = KEY_F1 + (i - 1);
> +
> +		input_set_capability(ts->input_dev, EV_KEY, ts-
> >keymap[i]);
> +	}
>  
>  	input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_X);
>  	input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_Y);

Re: [PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[Dmitry Torokhov]

Hi Dmitry,

On Mon, Mar 16, 2020 at 10:53:03AM +0300, Dmitry Mastykin wrote:
> +static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
> +{
> +	int touch_num;
> +	u8 key_value;
> +	int i;
> +
> +	if (data[0] & GOODIX_HAVE_KEY) {
> +		touch_num = data[0] & 0x0f;
> +		key_value = data[1 + ts->contact_size * touch_num];
> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> +			if (key_value & (1 << i))
> +				input_report_key(ts->input_dev, ts->keymap[i], 1);
> +	} else
> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> +			input_report_key(ts->input_dev, ts->keymap[i], 0);

Should this be written as:

	if (data[0] & GOODIX_HAVE_KEY) {
		touch_num = data[0] & 0x0f;
		key_value = data[1 + ts->contact_size * touch_num];
	} else {
		/* Release all keys */
		key_value = 0;
	}

	for (i = 0; i < GOODIX_MAX_KEYS; i++)
		input_report_key(ts->input_dev, ts->keymap[i],
				 key_value & BIT(i);

or the device may send incremental updates to the keys pressed without
resending currently pressed keys (sounds unlikely)?

Thanks.

-- 
Dmitry

Re: [PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[Dmitry Mastykin]

Hi Dmitry,
we had discussed earlier this point with Hans:

Hans:
 >>> 3) In goodix_ts_report_key you do:
 >>>
 >>>                   for (i = 0; i < GOODIX_MAX_KEYS; ++i)
 >>>                           if (key_value & (1 << i))
 >>>                                   input_report_key(ts->input_dev, 
ts->keymap[i], 1
 >>>
 >>> But if the user then jumps his finger from say touch_key 0 to 
touch_key 1
 >>> without us receiving a "packet" in between with GOODIX_HAVE_KEY set,
 >>> then we never release touch_key 0. So instead this really should be:
 >>>
 >>>                   for (i = 0; i < GOODIX_MAX_KEYS; ++i)
 >>>                           input_report_key(ts->input_dev, 
ts->keymap[i],
 >>>                                            key_value & (1 << i));
 >>>

Me:
 >> It seems, that this problem never happens. When user moves finger from
 >> button to button, we stably receive 2-3 packets without
 >> GOODIX_HAVE_KEY in between, that release all previous touches. From
 >> other hand, your change will not work when the same keycode is
 >> assigned to several buttons - it will be immediately released.

Hans:
 >
 > Hmm, interesting point I did not think of that. That would be a bit
 > weird thing to do, but it is not impossible...
 >
 > I'm afraid Dmitry (the input maintainer) will likely make the same
 > remark as I do though (when you submit this upstream). But we'll see.
 >
 > Keeping this as is is fine with me.

So I'm impressed about your mutual understanding) And waiting for your 
decision.
Thank you!

Kind regards
Dmitry Mastykin

On 3/24/20 9:51 PM, Dmitry Torokhov wrote:
> Hi Dmitry,
> 
> On Mon, Mar 16, 2020 at 10:53:03AM +0300, Dmitry Mastykin wrote:
>> +static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
>> +{
>> +	int touch_num;
>> +	u8 key_value;
>> +	int i;
>> +
>> +	if (data[0] & GOODIX_HAVE_KEY) {
>> +		touch_num = data[0] & 0x0f;
>> +		key_value = data[1 + ts->contact_size * touch_num];
>> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
>> +			if (key_value & (1 << i))
>> +				input_report_key(ts->input_dev, ts->keymap[i], 1);
>> +	} else
>> +		for (i = 0; i < GOODIX_MAX_KEYS; ++i)
>> +			input_report_key(ts->input_dev, ts->keymap[i], 0);
> 
> Should this be written as:
> 
> 	if (data[0] & GOODIX_HAVE_KEY) {
> 		touch_num = data[0] & 0x0f;
> 		key_value = data[1 + ts->contact_size * touch_num];
> 	} else {
> 		/* Release all keys */
> 		key_value = 0;
> 	}
> 
> 	for (i = 0; i < GOODIX_MAX_KEYS; i++)
> 		input_report_key(ts->input_dev, ts->keymap[i],
> 				 key_value & BIT(i);
> 
> or the device may send incremental updates to the keys pressed without
> resending currently pressed keys (sounds unlikely)?
> 
> Thanks.
> 

Re: [PATCH v3 1/2] Input: goodix - Add support for more then one touch-key

[Dmitry Torokhov]

On Tue, Mar 24, 2020 at 10:38:10PM +0300, Dmitry Mastykin wrote:
> Hi Dmitry,
> we had discussed earlier this point with Hans:
> 
> Hans:
> >>> 3) In goodix_ts_report_key you do:
> >>>
> >>>                   for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> >>>                           if (key_value & (1 << i))
> >>>                                   input_report_key(ts->input_dev,
> ts->keymap[i], 1
> >>>
> >>> But if the user then jumps his finger from say touch_key 0 to touch_key
> 1
> >>> without us receiving a "packet" in between with GOODIX_HAVE_KEY set,
> >>> then we never release touch_key 0. So instead this really should be:
> >>>
> >>>                   for (i = 0; i < GOODIX_MAX_KEYS; ++i)
> >>>                           input_report_key(ts->input_dev, ts->keymap[i],
> >>>                                            key_value & (1 << i));
> >>>
> 
> Me:
> >> It seems, that this problem never happens. When user moves finger from
> >> button to button, we stably receive 2-3 packets without
> >> GOODIX_HAVE_KEY in between, that release all previous touches. From
> >> other hand, your change will not work when the same keycode is
> >> assigned to several buttons - it will be immediately released.
> 
> Hans:
> >
> > Hmm, interesting point I did not think of that. That would be a bit
> > weird thing to do, but it is not impossible...
> >
> > I'm afraid Dmitry (the input maintainer) will likely make the same
> > remark as I do though (when you submit this upstream). But we'll see.
> >
> > Keeping this as is is fine with me.
> 
> So I'm impressed about your mutual understanding) And waiting for your
> decision.

OK, I'll apply as is then. Thank you.

-- 
Dmitry