diff mbox series

[4/4] Input: goodix - Add pen support

Message ID 20211206164747.197309-5-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show
Series Input: goodix - pen support + misc patches | expand

Commit Message

Hans de Goede Dec. 6, 2021, 4:47 p.m. UTC 
Some Goodix touchscreens have support for a (Goodix) active pen, add
support for this. The info on how to detect when a pen is down and to
detect when the stylus buttons are pressed was lifted from the out
of tree Goodix driver with pen support written by Adya:
https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/

Since there is no way to tell if pen support is present, the registering
of the pen input_dev is delayed till the first pen event is detected.

This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
a Cyberbook T116 tablet.

Link: https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/input/touchscreen/goodix.c | 122 ++++++++++++++++++++++++++++-
 drivers/input/touchscreen/goodix.h |   1 +
 2 files changed, 121 insertions(+), 2 deletions(-)

Comments

Dmitry Torokhov Dec. 7, 2021, 5:50 p.m. UTC | #1 
On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:
> Some Goodix touchscreens have support for a (Goodix) active pen, add
> support for this. The info on how to detect when a pen is down and to
> detect when the stylus buttons are pressed was lifted from the out
> of tree Goodix driver with pen support written by Adya:
> https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
> 
> Since there is no way to tell if pen support is present, the registering
> of the pen input_dev is delayed till the first pen event is detected.
> 
> This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
> a Cyberbook T116 tablet.
> 
> Link: https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/input/touchscreen/goodix.c | 122 ++++++++++++++++++++++++++++-
>  drivers/input/touchscreen/goodix.h |   1 +
>  2 files changed, 121 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index 2d38a941e7e4..691e4505cf4a 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -298,6 +298,107 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
>  	return -ENOMSG;
>  }
>  
> +static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
> +{
> +	struct device *dev = &ts->client->dev;
> +	struct input_dev *input;
> +
> +	input = devm_input_allocate_device(dev);
> +	if (!input)
> +		return NULL;
> +
> +	input_alloc_absinfo(input);
> +	if (!input->absinfo) {
> +		input_free_device(input);
> +		return NULL;
> +	}

Please drop this as input_abs_set_max() will do allocation and
input_register_device() will reject device with ABS_* events without
absinfo allocated.

> +
> +	input->absinfo[ABS_X] = ts->input_dev->absinfo[ABS_MT_POSITION_X];

	input_abs_set_max(input, ABS_X,
		input_abs_get_max(input, ABS_MT_POSITION_X);

or even maybe

	input_set_abs_params(input, ABS_X,
		0, input_abs_get_max(input, ABS_MT_POSITION_X), 0, 0);


> +	input->absinfo[ABS_Y] = ts->input_dev->absinfo[ABS_MT_POSITION_Y];
> +	__set_bit(ABS_X, input->absbit);
> +	__set_bit(ABS_Y, input->absbit);

This might not be needed, depending...

> +	input_set_abs_params(input, ABS_PRESSURE, 0, 255, 0, 0);
> +
> +	input_set_capability(input, EV_KEY, BTN_TOUCH);
> +	input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
> +	input_set_capability(input, EV_KEY, BTN_STYLUS);
> +	input_set_capability(input, EV_KEY, BTN_STYLUS2);
> +	__set_bit(INPUT_PROP_DIRECT, input->propbit);
> +	/*
> +	 * The resolution of these touchscreens is about 10 units/mm, the actual
> +	 * resolution does not matter much since we set INPUT_PROP_DIRECT.
> +	 * Userspace wants something here though, so just set it to 10 units/mm.
> +	 */
> +	input_abs_set_res(input, ABS_X, 10);
> +	input_abs_set_res(input, ABS_Y, 10);

Could it be moved next to setting up axes?

> +
> +	input->name = "Goodix Active Pen";
> +	input->phys = "input/pen";
> +	input->id.bustype = BUS_I2C;
> +	if (kstrtou16(ts->id, 10, &input->id.product))
> +		input->id.product = 0x1001;
> +	input->id.version = ts->version;
> +
> +	if (input_register_device(input) != 0) {
> +		input_free_device(input);

Warrants a comment on why we need to free devm.

Is it going to be safely destroyed on removal? It is likely to happen
very first thing, before we deal with interrupts, etc.


> +		return NULL;
> +	}
> +
> +	return input;
> +}
> +
> +static void goodix_ts_report_pen_down(struct goodix_ts_data *ts, u8 *data)
> +{
> +	int input_x, input_y, input_w;
> +	u8 key_value;
> +
> +	if (!ts->input_pen) {
> +		ts->input_pen = goodix_create_pen_input(ts);
> +		if (!ts->input_pen)
> +			return;
> +	}
> +
> +	if (ts->contact_size == 9) {
> +		input_x = get_unaligned_le16(&data[4]);
> +		input_y = get_unaligned_le16(&data[6]);
> +		input_w = get_unaligned_le16(&data[8]);
> +	} else {
> +		input_x = get_unaligned_le16(&data[2]);
> +		input_y = get_unaligned_le16(&data[4]);
> +		input_w = get_unaligned_le16(&data[6]);
> +	}
> +
> +	touchscreen_report_pos(ts->input_pen, &ts->prop, input_x, input_y, false);
> +	input_report_abs(ts->input_pen, ABS_PRESSURE, input_w);
> +
> +	input_report_key(ts->input_pen, BTN_TOUCH, 1);
> +	input_report_key(ts->input_pen, BTN_TOOL_PEN, 1);
> +
> +	if (data[0] & GOODIX_HAVE_KEY) {
> +		key_value = data[1 + ts->contact_size];
> +		input_report_key(ts->input_pen, BTN_STYLUS, key_value & 0x10);
> +		input_report_key(ts->input_pen, BTN_STYLUS2, key_value & 0x20);

Use BIT?

> +	} else {
> +		input_report_key(ts->input_pen, BTN_STYLUS, 0);
> +		input_report_key(ts->input_pen, BTN_STYLUS2, 0);
> +	}
> +
> +	input_sync(ts->input_pen);
> +}
> +
> +static void goodix_ts_report_pen_up(struct goodix_ts_data *ts)
> +{
> +	if (!ts->input_pen)
> +		return;
> +
> +	input_report_key(ts->input_pen, BTN_TOUCH, 0);
> +	input_report_key(ts->input_pen, BTN_TOOL_PEN, 0);
> +	input_report_key(ts->input_pen, BTN_STYLUS, 0);
> +	input_report_key(ts->input_pen, BTN_STYLUS2, 0);
> +
> +	input_sync(ts->input_pen);
> +}
> +
>  static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)
>  {
>  	int id = coor_data[0] & 0x0F;
> @@ -328,6 +429,14 @@ 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_release_keys(struct goodix_ts_data *ts)
> +{
> +	int i;
> +
> +	for (i = 0; i < GOODIX_MAX_KEYS; i++)
> +		input_report_key(ts->input_dev, ts->keymap[i], 0);
> +}
> +
>  static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
>  {
>  	int touch_num;
> @@ -342,8 +451,7 @@ static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
>  				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_ts_release_keys(ts);
>  	}
>  }
>  
> @@ -365,6 +473,15 @@ static void goodix_process_events(struct goodix_ts_data *ts)
>  	if (touch_num < 0)
>  		return;
>  
> +	/* The pen being down is always reported as a single touch */
> +	if (touch_num == 1 && (point_data[1] & 0x80)) {
> +		goodix_ts_report_pen_down(ts, point_data);
> +		goodix_ts_release_keys(ts);
> +		goto sync; /* Release any previousle registered touches */
> +	} else {

Not sure why we need else with goto...

> +		goodix_ts_report_pen_up(ts);
> +	}
> +
>  	goodix_ts_report_key(ts, point_data);
>  
>  	for (i = 0; i < touch_num; i++)
> @@ -375,6 +492,7 @@ static void goodix_process_events(struct goodix_ts_data *ts)
>  			goodix_ts_report_touch_8b(ts,
>  				&point_data[1 + ts->contact_size * i]);
>  
> +sync:
>  	input_mt_sync_frame(ts->input_dev);
>  	input_sync(ts->input_dev);
>  }
> diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
> index 02065d1c3263..fa8602e78a64 100644
> --- a/drivers/input/touchscreen/goodix.h
> +++ b/drivers/input/touchscreen/goodix.h
> @@ -76,6 +76,7 @@ struct goodix_chip_data {
>  struct goodix_ts_data {
>  	struct i2c_client *client;
>  	struct input_dev *input_dev;
> +	struct input_dev *input_pen;
>  	const struct goodix_chip_data *chip;
>  	const char *firmware_name;
>  	struct touchscreen_properties prop;
> -- 
> 2.33.1
> 

Thanks.
Hans de Goede Dec. 8, 2021, 8:37 a.m. UTC | #2 
Hi Dmitry,

Thank you for the review.

On 12/7/21 18:50, Dmitry Torokhov wrote:
> On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:
>> Some Goodix touchscreens have support for a (Goodix) active pen, add
>> support for this. The info on how to detect when a pen is down and to
>> detect when the stylus buttons are pressed was lifted from the out
>> of tree Goodix driver with pen support written by Adya:
>> https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
>>
>> Since there is no way to tell if pen support is present, the registering
>> of the pen input_dev is delayed till the first pen event is detected.
>>
>> This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
>> a Cyberbook T116 tablet.
>>
>> Link: https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  drivers/input/touchscreen/goodix.c | 122 ++++++++++++++++++++++++++++-
>>  drivers/input/touchscreen/goodix.h |   1 +
>>  2 files changed, 121 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
>> index 2d38a941e7e4..691e4505cf4a 100644
>> --- a/drivers/input/touchscreen/goodix.c
>> +++ b/drivers/input/touchscreen/goodix.c
>> @@ -298,6 +298,107 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
>>  	return -ENOMSG;
>>  }
>>  
>> +static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
>> +{
>> +	struct device *dev = &ts->client->dev;
>> +	struct input_dev *input;
>> +
>> +	input = devm_input_allocate_device(dev);
>> +	if (!input)
>> +		return NULL;
>> +
>> +	input_alloc_absinfo(input);
>> +	if (!input->absinfo) {
>> +		input_free_device(input);
>> +		return NULL;
>> +	}
> 
> Please drop this as input_abs_set_max() will do allocation and
> input_register_device() will reject device with ABS_* events without
> absinfo allocated.
> 
>> +
>> +	input->absinfo[ABS_X] = ts->input_dev->absinfo[ABS_MT_POSITION_X];
> 
> 	input_abs_set_max(input, ABS_X,
> 		input_abs_get_max(input, ABS_MT_POSITION_X);
> 
> or even maybe
> 
> 	input_set_abs_params(input, ABS_X,
> 		0, input_abs_get_max(input, ABS_MT_POSITION_X), 0, 0);

The reason why I'm just copying the entire absinfo struct
(and thus need the NULL check above) is because this driver uses
touchscreen_parse_properties(), so the min and fuzz values
might (theoretically) also be set through device-properties and
I wanted to cover that.

Since you don't like the above approach, I will go with the following
for the next version:

	input_set_abs_params(input, ABS_X,
			     input_abs_get_min(ts->input_dev, ABS_MT_POSITION_X),
			     input_abs_get_max(ts->input_dev, ABS_MT_POSITION_X),
			     input_abs_get_fuzz(ts->input_dev, ABS_MT_POSITION_X),
			     input_abs_get_flat(ts->input_dev, ABS_MT_POSITION_X));

(and the same for the Y axis).


> 
> 
>> +	input->absinfo[ABS_Y] = ts->input_dev->absinfo[ABS_MT_POSITION_Y];
>> +	__set_bit(ABS_X, input->absbit);
>> +	__set_bit(ABS_Y, input->absbit);
> 
> This might not be needed, depending...

Ack, will drop.

> 
>> +	input_set_abs_params(input, ABS_PRESSURE, 0, 255, 0, 0);
>> +
>> +	input_set_capability(input, EV_KEY, BTN_TOUCH);
>> +	input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
>> +	input_set_capability(input, EV_KEY, BTN_STYLUS);
>> +	input_set_capability(input, EV_KEY, BTN_STYLUS2);
>> +	__set_bit(INPUT_PROP_DIRECT, input->propbit);
>> +	/*
>> +	 * The resolution of these touchscreens is about 10 units/mm, the actual
>> +	 * resolution does not matter much since we set INPUT_PROP_DIRECT.
>> +	 * Userspace wants something here though, so just set it to 10 units/mm.
>> +	 */
>> +	input_abs_set_res(input, ABS_X, 10);
>> +	input_abs_set_res(input, ABS_Y, 10);
> 
> Could it be moved next to setting up axes?

Ack, will do.

> 
>> +
>> +	input->name = "Goodix Active Pen";
>> +	input->phys = "input/pen";
>> +	input->id.bustype = BUS_I2C;
>> +	if (kstrtou16(ts->id, 10, &input->id.product))
>> +		input->id.product = 0x1001;
>> +	input->id.version = ts->version;
>> +
>> +	if (input_register_device(input) != 0) {
>> +		input_free_device(input);
> 
> Warrants a comment on why we need to free devm.
> 
> Is it going to be safely destroyed on removal? It is likely to happen
> very first thing, before we deal with interrupts, etc.

That is a very good point, since I've chosen to create the pen
input device on the first pen event, it happens after the interrupts
have been registered. So that means the driver can no longer rely
on the devm reverse-teardown order to get things right.

For the next version I will always allocate the device and only
register it on the fly. Since the devres is created when allocating
this will fix this ordering problem. The device will then still
unregister before the irq gets disabled, but it will not be
free-ed, so the irq can still safely use it.

>> +		return NULL;
>> +	}
>> +
>> +	return input;
>> +}
>> +
>> +static void goodix_ts_report_pen_down(struct goodix_ts_data *ts, u8 *data)
>> +{
>> +	int input_x, input_y, input_w;
>> +	u8 key_value;
>> +
>> +	if (!ts->input_pen) {
>> +		ts->input_pen = goodix_create_pen_input(ts);
>> +		if (!ts->input_pen)
>> +			return;
>> +	}
>> +
>> +	if (ts->contact_size == 9) {
>> +		input_x = get_unaligned_le16(&data[4]);
>> +		input_y = get_unaligned_le16(&data[6]);
>> +		input_w = get_unaligned_le16(&data[8]);
>> +	} else {
>> +		input_x = get_unaligned_le16(&data[2]);
>> +		input_y = get_unaligned_le16(&data[4]);
>> +		input_w = get_unaligned_le16(&data[6]);
>> +	}
>> +
>> +	touchscreen_report_pos(ts->input_pen, &ts->prop, input_x, input_y, false);
>> +	input_report_abs(ts->input_pen, ABS_PRESSURE, input_w);
>> +
>> +	input_report_key(ts->input_pen, BTN_TOUCH, 1);
>> +	input_report_key(ts->input_pen, BTN_TOOL_PEN, 1);
>> +
>> +	if (data[0] & GOODIX_HAVE_KEY) {
>> +		key_value = data[1 + ts->contact_size];
>> +		input_report_key(ts->input_pen, BTN_STYLUS, key_value & 0x10);
>> +		input_report_key(ts->input_pen, BTN_STYLUS2, key_value & 0x20);
> 
> Use BIT?

Ack.

> 
>> +	} else {
>> +		input_report_key(ts->input_pen, BTN_STYLUS, 0);
>> +		input_report_key(ts->input_pen, BTN_STYLUS2, 0);
>> +	}
>> +
>> +	input_sync(ts->input_pen);
>> +}
>> +
>> +static void goodix_ts_report_pen_up(struct goodix_ts_data *ts)
>> +{
>> +	if (!ts->input_pen)
>> +		return;
>> +
>> +	input_report_key(ts->input_pen, BTN_TOUCH, 0);
>> +	input_report_key(ts->input_pen, BTN_TOOL_PEN, 0);
>> +	input_report_key(ts->input_pen, BTN_STYLUS, 0);
>> +	input_report_key(ts->input_pen, BTN_STYLUS2, 0);
>> +
>> +	input_sync(ts->input_pen);
>> +}
>> +
>>  static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)
>>  {
>>  	int id = coor_data[0] & 0x0F;
>> @@ -328,6 +429,14 @@ 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_release_keys(struct goodix_ts_data *ts)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < GOODIX_MAX_KEYS; i++)
>> +		input_report_key(ts->input_dev, ts->keymap[i], 0);
>> +}
>> +
>>  static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
>>  {
>>  	int touch_num;
>> @@ -342,8 +451,7 @@ static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
>>  				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_ts_release_keys(ts);
>>  	}
>>  }
>>  
>> @@ -365,6 +473,15 @@ static void goodix_process_events(struct goodix_ts_data *ts)
>>  	if (touch_num < 0)
>>  		return;
>>  
>> +	/* The pen being down is always reported as a single touch */
>> +	if (touch_num == 1 && (point_data[1] & 0x80)) {
>> +		goodix_ts_report_pen_down(ts, point_data);
>> +		goodix_ts_release_keys(ts);
>> +		goto sync; /* Release any previousle registered touches */
>> +	} else {
> 
> Not sure why we need else with goto...

It is not needed, I wrote it this way for readability, one is the
pen down path and the other the pen up path, so having that as
an if ... else ... feels more natural to me.

I plan to keep this for the next version, but if you strongly dislike this
let me know and/or feel free to modify this when you merge the next version.

Regards,

Hans


> 
>> +		goodix_ts_report_pen_up(ts);
>> +	}
>> +
>>  	goodix_ts_report_key(ts, point_data);
>>  
>>  	for (i = 0; i < touch_num; i++)
>> @@ -375,6 +492,7 @@ static void goodix_process_events(struct goodix_ts_data *ts)
>>  			goodix_ts_report_touch_8b(ts,
>>  				&point_data[1 + ts->contact_size * i]);
>>  
>> +sync:
>>  	input_mt_sync_frame(ts->input_dev);
>>  	input_sync(ts->input_dev);
>>  }
>> diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
>> index 02065d1c3263..fa8602e78a64 100644
>> --- a/drivers/input/touchscreen/goodix.h
>> +++ b/drivers/input/touchscreen/goodix.h
>> @@ -76,6 +76,7 @@ struct goodix_chip_data {
>>  struct goodix_ts_data {
>>  	struct i2c_client *client;
>>  	struct input_dev *input_dev;
>> +	struct input_dev *input_pen;
>>  	const struct goodix_chip_data *chip;
>>  	const char *firmware_name;
>>  	struct touchscreen_properties prop;
>> -- 
>> 2.33.1
>>
> 
> Thanks.
>
Dmitry Torokhov Dec. 8, 2021, 8:51 a.m. UTC | #3 
On Wed, Dec 8, 2021 at 12:37 AM Hans de Goede <hdegoede@redhat.com> wrote:
>
> Hi Dmitry,
>
> Thank you for the review.
>
> On 12/7/21 18:50, Dmitry Torokhov wrote:
> > On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:
> >> Some Goodix touchscreens have support for a (Goodix) active pen, add
> >> support for this. The info on how to detect when a pen is down and to
> >> detect when the stylus buttons are pressed was lifted from the out
> >> of tree Goodix driver with pen support written by Adya:
> >> https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
> >>
> >> Since there is no way to tell if pen support is present, the registering
> >> of the pen input_dev is delayed till the first pen event is detected.
> >>
> >> This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
> >> a Cyberbook T116 tablet.
> >>
> >> Link: https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
> >> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
> >> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >> ---
> >>  drivers/input/touchscreen/goodix.c | 122 ++++++++++++++++++++++++++++-
> >>  drivers/input/touchscreen/goodix.h |   1 +
> >>  2 files changed, 121 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> >> index 2d38a941e7e4..691e4505cf4a 100644
> >> --- a/drivers/input/touchscreen/goodix.c
> >> +++ b/drivers/input/touchscreen/goodix.c
> >> @@ -298,6 +298,107 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
> >>      return -ENOMSG;
> >>  }
> >>
> >> +static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
> >> +{
> >> +    struct device *dev = &ts->client->dev;
> >> +    struct input_dev *input;
> >> +
> >> +    input = devm_input_allocate_device(dev);
> >> +    if (!input)
> >> +            return NULL;
> >> +
> >> +    input_alloc_absinfo(input);
> >> +    if (!input->absinfo) {
> >> +            input_free_device(input);
> >> +            return NULL;
> >> +    }
> >
> > Please drop this as input_abs_set_max() will do allocation and
> > input_register_device() will reject device with ABS_* events without
> > absinfo allocated.
> >
> >> +
> >> +    input->absinfo[ABS_X] = ts->input_dev->absinfo[ABS_MT_POSITION_X];
> >
> >       input_abs_set_max(input, ABS_X,
> >               input_abs_get_max(input, ABS_MT_POSITION_X);
> >
> > or even maybe
> >
> >       input_set_abs_params(input, ABS_X,
> >               0, input_abs_get_max(input, ABS_MT_POSITION_X), 0, 0);
>
> The reason why I'm just copying the entire absinfo struct
> (and thus need the NULL check above) is because this driver uses
> touchscreen_parse_properties(), so the min and fuzz values
> might (theoretically) also be set through device-properties and
> I wanted to cover that.
>
> Since you don't like the above approach, I will go with the following
> for the next version:
>
>         input_set_abs_params(input, ABS_X,
>                              input_abs_get_min(ts->input_dev, ABS_MT_POSITION_X),
>                              input_abs_get_max(ts->input_dev, ABS_MT_POSITION_X),
>                              input_abs_get_fuzz(ts->input_dev, ABS_MT_POSITION_X),
>                              input_abs_get_flat(ts->input_dev, ABS_MT_POSITION_X));
>
> (and the same for the Y axis).

Ah, sorry, I misread the code. It is fine as is then, or we could even
consider adding input_copy_abs(input, axis, src) that would allocate
absinfo if needed, set capability, and do the copy.

Thanks.
Hans de Goede Dec. 8, 2021, 5:02 p.m. UTC | #4 
Hi Dmitry,

On 12/8/21 09:51, Dmitry Torokhov wrote:
> On Wed, Dec 8, 2021 at 12:37 AM Hans de Goede <hdegoede@redhat.com> wrote:
>>
>> Hi Dmitry,
>>
>> Thank you for the review.
>>
>> On 12/7/21 18:50, Dmitry Torokhov wrote:
>>> On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:
>>>> Some Goodix touchscreens have support for a (Goodix) active pen, add
>>>> support for this. The info on how to detect when a pen is down and to
>>>> detect when the stylus buttons are pressed was lifted from the out
>>>> of tree Goodix driver with pen support written by Adya:
>>>> https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
>>>>
>>>> Since there is no way to tell if pen support is present, the registering
>>>> of the pen input_dev is delayed till the first pen event is detected.
>>>>
>>>> This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
>>>> a Cyberbook T116 tablet.
>>>>
>>>> Link: https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
>>>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
>>>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>>  drivers/input/touchscreen/goodix.c | 122 ++++++++++++++++++++++++++++-
>>>>  drivers/input/touchscreen/goodix.h |   1 +
>>>>  2 files changed, 121 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
>>>> index 2d38a941e7e4..691e4505cf4a 100644
>>>> --- a/drivers/input/touchscreen/goodix.c
>>>> +++ b/drivers/input/touchscreen/goodix.c
>>>> @@ -298,6 +298,107 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
>>>>      return -ENOMSG;
>>>>  }
>>>>
>>>> +static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
>>>> +{
>>>> +    struct device *dev = &ts->client->dev;
>>>> +    struct input_dev *input;
>>>> +
>>>> +    input = devm_input_allocate_device(dev);
>>>> +    if (!input)
>>>> +            return NULL;
>>>> +
>>>> +    input_alloc_absinfo(input);
>>>> +    if (!input->absinfo) {
>>>> +            input_free_device(input);
>>>> +            return NULL;
>>>> +    }
>>>
>>> Please drop this as input_abs_set_max() will do allocation and
>>> input_register_device() will reject device with ABS_* events without
>>> absinfo allocated.
>>>
>>>> +
>>>> +    input->absinfo[ABS_X] = ts->input_dev->absinfo[ABS_MT_POSITION_X];
>>>
>>>       input_abs_set_max(input, ABS_X,
>>>               input_abs_get_max(input, ABS_MT_POSITION_X);
>>>
>>> or even maybe
>>>
>>>       input_set_abs_params(input, ABS_X,
>>>               0, input_abs_get_max(input, ABS_MT_POSITION_X), 0, 0);
>>
>> The reason why I'm just copying the entire absinfo struct
>> (and thus need the NULL check above) is because this driver uses
>> touchscreen_parse_properties(), so the min and fuzz values
>> might (theoretically) also be set through device-properties and
>> I wanted to cover that.
>>
>> Since you don't like the above approach, I will go with the following
>> for the next version:
>>
>>         input_set_abs_params(input, ABS_X,
>>                              input_abs_get_min(ts->input_dev, ABS_MT_POSITION_X),
>>                              input_abs_get_max(ts->input_dev, ABS_MT_POSITION_X),
>>                              input_abs_get_fuzz(ts->input_dev, ABS_MT_POSITION_X),
>>                              input_abs_get_flat(ts->input_dev, ABS_MT_POSITION_X));
>>
>> (and the same for the Y axis).
> 
> Ah, sorry, I misread the code. It is fine as is then, or we could even
> consider adding input_copy_abs(input, axis, src) that would allocate
> absinfo if needed, set capability, and do the copy.

Oh, I think that adding an input_copy_abs() helper for this is actually
a good idea. I'll do that for the next version (in a separate patch of course).

Regards,

Hans
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 2d38a941e7e4..691e4505cf4a 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -298,6 +298,107 @@  static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 	return -ENOMSG;
 }
 
+static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
+{
+	struct device *dev = &ts->client->dev;
+	struct input_dev *input;
+
+	input = devm_input_allocate_device(dev);
+	if (!input)
+		return NULL;
+
+	input_alloc_absinfo(input);
+	if (!input->absinfo) {
+		input_free_device(input);
+		return NULL;
+	}
+
+	input->absinfo[ABS_X] = ts->input_dev->absinfo[ABS_MT_POSITION_X];
+	input->absinfo[ABS_Y] = ts->input_dev->absinfo[ABS_MT_POSITION_Y];
+	__set_bit(ABS_X, input->absbit);
+	__set_bit(ABS_Y, input->absbit);
+	input_set_abs_params(input, ABS_PRESSURE, 0, 255, 0, 0);
+
+	input_set_capability(input, EV_KEY, BTN_TOUCH);
+	input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
+	input_set_capability(input, EV_KEY, BTN_STYLUS);
+	input_set_capability(input, EV_KEY, BTN_STYLUS2);
+	__set_bit(INPUT_PROP_DIRECT, input->propbit);
+	/*
+	 * The resolution of these touchscreens is about 10 units/mm, the actual
+	 * resolution does not matter much since we set INPUT_PROP_DIRECT.
+	 * Userspace wants something here though, so just set it to 10 units/mm.
+	 */
+	input_abs_set_res(input, ABS_X, 10);
+	input_abs_set_res(input, ABS_Y, 10);
+
+	input->name = "Goodix Active Pen";
+	input->phys = "input/pen";
+	input->id.bustype = BUS_I2C;
+	if (kstrtou16(ts->id, 10, &input->id.product))
+		input->id.product = 0x1001;
+	input->id.version = ts->version;
+
+	if (input_register_device(input) != 0) {
+		input_free_device(input);
+		return NULL;
+	}
+
+	return input;
+}
+
+static void goodix_ts_report_pen_down(struct goodix_ts_data *ts, u8 *data)
+{
+	int input_x, input_y, input_w;
+	u8 key_value;
+
+	if (!ts->input_pen) {
+		ts->input_pen = goodix_create_pen_input(ts);
+		if (!ts->input_pen)
+			return;
+	}
+
+	if (ts->contact_size == 9) {
+		input_x = get_unaligned_le16(&data[4]);
+		input_y = get_unaligned_le16(&data[6]);
+		input_w = get_unaligned_le16(&data[8]);
+	} else {
+		input_x = get_unaligned_le16(&data[2]);
+		input_y = get_unaligned_le16(&data[4]);
+		input_w = get_unaligned_le16(&data[6]);
+	}
+
+	touchscreen_report_pos(ts->input_pen, &ts->prop, input_x, input_y, false);
+	input_report_abs(ts->input_pen, ABS_PRESSURE, input_w);
+
+	input_report_key(ts->input_pen, BTN_TOUCH, 1);
+	input_report_key(ts->input_pen, BTN_TOOL_PEN, 1);
+
+	if (data[0] & GOODIX_HAVE_KEY) {
+		key_value = data[1 + ts->contact_size];
+		input_report_key(ts->input_pen, BTN_STYLUS, key_value & 0x10);
+		input_report_key(ts->input_pen, BTN_STYLUS2, key_value & 0x20);
+	} else {
+		input_report_key(ts->input_pen, BTN_STYLUS, 0);
+		input_report_key(ts->input_pen, BTN_STYLUS2, 0);
+	}
+
+	input_sync(ts->input_pen);
+}
+
+static void goodix_ts_report_pen_up(struct goodix_ts_data *ts)
+{
+	if (!ts->input_pen)
+		return;
+
+	input_report_key(ts->input_pen, BTN_TOUCH, 0);
+	input_report_key(ts->input_pen, BTN_TOOL_PEN, 0);
+	input_report_key(ts->input_pen, BTN_STYLUS, 0);
+	input_report_key(ts->input_pen, BTN_STYLUS2, 0);
+
+	input_sync(ts->input_pen);
+}
+
 static void goodix_ts_report_touch_8b(struct goodix_ts_data *ts, u8 *coor_data)
 {
 	int id = coor_data[0] & 0x0F;
@@ -328,6 +429,14 @@  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_release_keys(struct goodix_ts_data *ts)
+{
+	int i;
+
+	for (i = 0; i < GOODIX_MAX_KEYS; i++)
+		input_report_key(ts->input_dev, ts->keymap[i], 0);
+}
+
 static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
 {
 	int touch_num;
@@ -342,8 +451,7 @@  static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
 				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_ts_release_keys(ts);
 	}
 }
 
@@ -365,6 +473,15 @@  static void goodix_process_events(struct goodix_ts_data *ts)
 	if (touch_num < 0)
 		return;
 
+	/* The pen being down is always reported as a single touch */
+	if (touch_num == 1 && (point_data[1] & 0x80)) {
+		goodix_ts_report_pen_down(ts, point_data);
+		goodix_ts_release_keys(ts);
+		goto sync; /* Release any previousle registered touches */
+	} else {
+		goodix_ts_report_pen_up(ts);
+	}
+
 	goodix_ts_report_key(ts, point_data);
 
 	for (i = 0; i < touch_num; i++)
@@ -375,6 +492,7 @@  static void goodix_process_events(struct goodix_ts_data *ts)
 			goodix_ts_report_touch_8b(ts,
 				&point_data[1 + ts->contact_size * i]);
 
+sync:
 	input_mt_sync_frame(ts->input_dev);
 	input_sync(ts->input_dev);
 }
diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
index 02065d1c3263..fa8602e78a64 100644
--- a/drivers/input/touchscreen/goodix.h
+++ b/drivers/input/touchscreen/goodix.h
@@ -76,6 +76,7 @@  struct goodix_chip_data {
 struct goodix_ts_data {
 	struct i2c_client *client;
 	struct input_dev *input_dev;
+	struct input_dev *input_pen;
 	const struct goodix_chip_data *chip;
 	const char *firmware_name;
 	struct touchscreen_properties prop;