[PATCH 0/4] Input: goodix - pen support + misc patches

Hi Dmitry,

Here is a patch-series for the Goodix touchscreen drivers, this is based
on top of the " Input: goodix - Try not to touch the reset-pin on
x86/ACPI devices" fix from earlier today (there are no conflicts
AFAIK, so the 2 can be merged independently).

This series consist of 3 small fixes/cleanups, followed by adding
pen (Goodix active stylus) support, which is supported on some
Goodix touchscreens.

Regards,

Hans


Hans de Goede (4):
  Input: goodix - Add id->model mapping for the "9111" model
  Input: goodix - Improve gpiod_get() error logging
  Input: goodix - Use the new soc_intel_is_byt() helper
  Input: goodix - Add pen support

 drivers/input/touchscreen/goodix.c | 162 +++++++++++++++++++++++------
 drivers/input/touchscreen/goodix.h |   1 +
 2 files changed, 131 insertions(+), 32 deletions(-)

-- 
2.33.1

goodix_get_gpio_config() errors are fatal (abort probe()) so log them
at KERN_ERR level rather then as debug messages.

This change uses dev_err_probe() to automatically suppress the errors
in case of -EPROBE_DEFER.

Signed-off-by: Hans de Goede <redacted>
---
 drivers/input/touchscreen/goodix.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index aaa3c455e01e..73f3b24f7f1e 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c

@@ -854,13 +854,10 @@ static int goodix_get_gpio_config(struct goodix_ts_data *ts)
 retry_get_irq_gpio:
 	/* Get the interrupt GPIO pin number */
 	gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_INT_NAME, GPIOD_IN);
-	if (IS_ERR(gpiod)) {
-		error = PTR_ERR(gpiod);
-		if (error != -EPROBE_DEFER)
-			dev_dbg(dev, "Failed to get %s GPIO: %d\n",
-				GOODIX_GPIO_INT_NAME, error);
-		return error;
-	}
+	if (IS_ERR(gpiod))
+		return dev_err_probe(dev, PTR_ERR(gpiod), "getting %s GPIO\n",
+				     GOODIX_GPIO_INT_NAME);
+
 	if (!gpiod && has_acpi_companion(dev) && !added_acpi_mappings) {
 		added_acpi_mappings = true;
 		if (goodix_add_acpi_gpio_mappings(ts) == 0)

@@ -871,13 +868,9 @@ static int goodix_get_gpio_config(struct goodix_ts_data *ts)
 
 	/* Get the reset line GPIO pin number */
 	gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_RST_NAME, ts->gpiod_rst_flags);
-	if (IS_ERR(gpiod)) {
-		error = PTR_ERR(gpiod);
-		if (error != -EPROBE_DEFER)
-			dev_dbg(dev, "Failed to get %s GPIO: %d\n",
-				GOODIX_GPIO_RST_NAME, error);
-		return error;
-	}
+	if (IS_ERR(gpiod))
+		return dev_err_probe(dev, PTR_ERR(gpiod), "getting %s GPIO\n",
+				     GOODIX_GPIO_RST_NAME);
 
 	ts->gpiod_rst = gpiod;
 

-- 
2.33.1

Use the new soc_intel_is_byt() helper from
linux/platform_data/x86/soc.h.

Signed-off-by: Hans de Goede <redacted>
---
 drivers/input/touchscreen/goodix.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 73f3b24f7f1e..2d38a941e7e4 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c

@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/platform_data/x86/soc.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/of.h>

@@ -686,21 +687,6 @@ static int goodix_reset(struct goodix_ts_data *ts)
 }
 
 #ifdef ACPI_GPIO_SUPPORT
-#include <asm/cpu_device_id.h>
-#include <asm/intel-family.h>
-
-static const struct x86_cpu_id baytrail_cpu_ids[] = {
-	{ X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT, X86_FEATURE_ANY, },
-	{}
-};
-
-static inline bool is_byt(void)
-{
-	const struct x86_cpu_id *id = x86_match_cpu(baytrail_cpu_ids);
-
-	return !!id;
-}
-
 static const struct acpi_gpio_params first_gpio = { 0, 0, false };
 static const struct acpi_gpio_params second_gpio = { 1, 0, false };
 

@@ -784,7 +770,7 @@ static int goodix_add_acpi_gpio_mappings(struct goodix_ts_data *ts)
 		dev_info(dev, "Using ACPI INTI and INTO methods for IRQ pin access\n");
 		ts->irq_pin_access_method = IRQ_PIN_ACCESS_ACPI_METHOD;
 		gpio_mapping = acpi_goodix_reset_only_gpios;
-	} else if (is_byt() && ts->gpio_count == 2 && ts->gpio_int_idx == -1) {
+	} else if (soc_intel_is_byt() && ts->gpio_count == 2 && ts->gpio_int_idx == -1) {
 		dev_info(dev, "No ACPI GpioInt resource, assuming that the GPIO order is reset, int\n");
 		ts->irq_pin_access_method = IRQ_PIN_ACCESS_ACPI_GPIO;
 		gpio_mapping = acpi_goodix_int_last_gpios;

-- 
2.33.1

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 <redacted>
---
 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;
+	}
+
+	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;

-- 
2.33.1

Add d->model mapping for the "9111" model, this fixes uses using
a wrong config_len of 240 bytes while the "9111" model uses
only 186 bytes of config.

Signed-off-by: Hans de Goede <redacted>
---
 drivers/input/touchscreen/goodix.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index eaa659969097..aaa3c455e01e 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c

@@ -102,6 +102,7 @@ static const struct goodix_chip_id goodix_chip_ids[] = {
 	{ .id = "911", .data = &gt911_chip_data },
 	{ .id = "9271", .data = &gt911_chip_data },
 	{ .id = "9110", .data = &gt911_chip_data },
+	{ .id = "9111", .data = &gt911_chip_data },
 	{ .id = "927", .data = &gt911_chip_data },
 	{ .id = "928", .data = &gt911_chip_data },
 

-- 
2.33.1

On Mon, Dec 06, 2021 at 05:47:44PM +0100, Hans de Goede wrote:

Add d->model mapping for the "9111" model, this fixes uses using
a wrong config_len of 240 bytes while the "9111" model uses
only 186 bytes of config.

Signed-off-by: Hans de Goede <redacted>

Applied, thank you.

-- 
Dmitry

Hi Hans,

On Mon, Dec 06, 2021 at 05:47:45PM +0100, Hans de Goede wrote:

goodix_get_gpio_config() errors are fatal (abort probe()) so log them
at KERN_ERR level rather then as debug messages.

This change uses dev_err_probe() to automatically suppress the errors
in case of -EPROBE_DEFER.

I really believe that dev_err_probe() is wrong API as the providers
should be setting the reason for deferred probe failures.

Could you simply swap dev_dbg() for dev_err()?

Thanks.

-- 
Dmitry

Hi Dmitry,

On 12/7/21 08:31, Dmitry Torokhov wrote:

Hi Hans,

On Mon, Dec 06, 2021 at 05:47:45PM +0100, Hans de Goede wrote:

quoted

goodix_get_gpio_config() errors are fatal (abort probe()) so log them
at KERN_ERR level rather then as debug messages.

This change uses dev_err_probe() to automatically suppress the errors
in case of -EPROBE_DEFER.

I really believe that dev_err_probe() is wrong API as the providers
should be setting the reason for deferred probe failures.

Could you simply swap dev_dbg() for dev_err()?

Done for v2, which I'm sending out right away.

Note I've dropped the first patch for v2 since you said you
applied this.

Regards,

Hans


p.s.

Any chance you could also take a look at this 2 patch patch-series,
this has been pending for a while now:

https://lore.kernel.org/linux-input/20211122220637.11386-1-hdegoede@redhat.com/T/#t

On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:

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?

Not sure why we need else with goto...

Thanks.

-- 
Dmitry

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:

quoted

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 <redacted>
---
 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.

quoted

+
+	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).

quoted

+	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.

quoted

+	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.

quoted

+
+	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.

quoted

+		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.

quoted

+	} 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

quoted

+		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.

On Wed, Dec 8, 2021 at 12:37 AM Hans de Goede [off-list ref] wrote:

Hi Dmitry,

Thank you for the review.

On 12/7/21 18:50, Dmitry Torokhov wrote:

quoted

On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:

quoted

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 <redacted>
---
 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.

quoted

+
+    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.

-- 
Dmitry

Hi Dmitry,

On 12/8/21 09:51, Dmitry Torokhov wrote:

On Wed, Dec 8, 2021 at 12:37 AM Hans de Goede [off-list ref] wrote:

quoted

Hi Dmitry,

Thank you for the review.

On 12/7/21 18:50, Dmitry Torokhov wrote:

quoted

On Mon, Dec 06, 2021 at 05:47:47PM +0100, Hans de Goede wrote:

quoted

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 <redacted>
---
 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.

quoted

+
+    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