input: atmel_mxt_ts: detect touchpad from devicetree
PATCH 1/1 input: atmel_mxt_ts: detect touchpad from devicetree
The Samsung Chromebook Plus (rk3399-gru-kevin) has two of these controllers. One for the touchscreen and one for the touchpad. However the touchpad doesn't have any associated gpio buttons, so it shows up as another touchscreen.
This patch fixes it by matching the "atmel,atmel_mxt_tp" compatibility string in the device tree.
--- drivers/input/touchscreen/atmel_mxt_ts.c | 8 ++++++-- include/linux/platform_data/atmel_mxt_ts.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)
drivers/input/touchscreen/atmel_mxt_ts.c +6 -2
@@ -1945,8 +1945,7 @@ static int mxt_initialize_input_device(struct mxt_data *data)input_set_abs_params (input_dev,ABS_PRESSURE ,0 ,255 ,0 ,0 ); } -/* If device has buttons we assume it is a touchpad */ -if (pdata->t19_num_keys) { +if (pdata->touchpad) {mxt_set_up_as_touchpad (input_dev, data); mt_flags |=INPUT_MT_POINTER ; }else {
@@ -2936,6 +2935,9 @@ static const struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)if (!pdata)return ERR_PTR (-ENOMEM ); +if (of_device_is_compatible (np,"atmel,atmel_mxt_tp" )) + pdata->touchpad = true; +if (of_find_property (np,"linux,gpio-keymap" , &proplen)) { pdata->t19_num_keys = proplen /sizeof (u32);
@@ -2986,6 +2988,7 @@ static struct mxt_acpi_platform_data samus_platform_data[] = { .pdata = { .t19_num_keys = ARRAY_SIZE(samus_touchpad_buttons), .t19_keymap = samus_touchpad_buttons, + .touchpad = true, }, }, {
@@ -3011,6 +3014,7 @@ static struct mxt_acpi_platform_data chromebook_platform_data[] = { .pdata = { .t19_num_keys = ARRAY_SIZE(chromebook_tp_buttons), .t19_keymap = chromebook_tp_buttons, + .touchpad = true, }, }, {
include/linux/platform_data/atmel_mxt_ts.h +1 -0
@@ -24,6 +24,7 @@ enum mxt_suspend_mode {struct mxt_platform_data {unsigned long irqflags;u8 t19_num_keys; +u8 touchpad;const unsigned int *t19_keymap;enum mxt_suspend_mode suspend_mode; };
Signature · 1 line
2.14.2
Quoted 8 lines · Emil Renner Berthing
The Samsung Chromebook Plus (rk3399-gru-kevin) has two of these controllers. One for the touchscreen and one for the touchpad. However the touchpad doesn't have any associated gpio buttons, so it shows up as another touchscreen.
This patch fixes it by matching the "atmel,atmel_mxt_tp" compatibility string in the device tree.
Thanks. I think this makes sense, given there are already devices out there using "atmel_mxt_tp".
Is the hardcoded MXT_PIXELS_PER_MM going to cause issues on this new device?
I think you need to add this to Documentation/devicetree/bindings/input/atmel,maxtouch.txt
Quoted 61 lines
Signed-off-by Emil Renner Berthing <[email protected]>--- drivers/input/touchscreen/atmel_mxt_ts.c | 8 ++++++-- include/linux/platform_data/atmel_mxt_ts.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)drivers/input/touchscreen/atmel_mxt_ts.c +6
-2@@ -1945,8 +1945,7 @@ static int mxt_initialize_input_device(struct mxt_data *data)input_set_abs_params (input_dev,ABS_PRESSURE ,0 ,255 ,0 ,0 ); } -/* If device has buttons we assume it is a touchpad */ -if (pdata->t19_num_keys) { +if (pdata->touchpad) {mxt_set_up_as_touchpad (input_dev, data); mt_flags |=INPUT_MT_POINTER ; }else {@@ -2936,6 +2935,9 @@ static const struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)if (!pdata)return ERR_PTR (-ENOMEM ); +if (of_device_is_compatible (np,"atmel,atmel_mxt_tp" )) + pdata->touchpad = true; +if (of_find_property (np,"linux,gpio-keymap" , &proplen)) { pdata->t19_num_keys = proplen /sizeof (u32);@@ -2986,6 +2988,7 @@ static struct mxt_acpi_platform_data samus_platform_data[] = { .pdata = { .t19_num_keys = ARRAY_SIZE(samus_touchpad_buttons), .t19_keymap = samus_touchpad_buttons, + .touchpad = true, }, }, {@@ -3011,6 +3014,7 @@ static struct mxt_acpi_platform_data chromebook_platform_data[] = { .pdata = { .t19_num_keys = ARRAY_SIZE(chromebook_tp_buttons), .t19_keymap = chromebook_tp_buttons, + .touchpad = true, }, }, {include/linux/platform_data/atmel_mxt_ts.h +1
-0@@ -24,6 +24,7 @@ enum mxt_suspend_mode {struct mxt_platform_data {unsigned long irqflags;u8 t19_num_keys; +u8 touchpad;const unsigned int *t19_keymap;enum mxt_suspend_mode suspend_mode; };Signature · 1 line
2.14.2
Quoted 7 lines · Nick Dyer
Quoted 6 lines · Emil Renner Berthing
The Samsung Chromebook Plus (rk3399-gru-kevin) has two of these controllers. One for the touchscreen and one for the touchpad. However the touchpad doesn't have any associated gpio buttons, so it shows up as another touchscreen.
Quoted 8 lines
Quoted 2 lines
This patch fixes it by matching the "atmel,atmel_mxt_tp" compatibility string in the device tree.
Thanks. I think this makes sense, given there are already devices out there using "
atmel_mxt_tp".Is the hardcoded
MXT_PIXELS_PER_MMgoing to cause issues on this new device?
I'm not exactly sure what kind of issues a wrong value would give, but the touchpad feels totally usable in X with libinput.
I just checked google's chromeos kernel and it seems to use the same hard-coded value.
Quoted 2 lines
I think you need to add this to
Documentation/devicetree/bindings/input/atmel,maxtouch.txt
Speaking of issues I was just about to complain that the "click button" in the touchpad
didn't work, but only touch. It turns out I completely misunderstood what those "gpio buttons" was all about. Adding
+ linux,gpio-keymap = <KEY_RESERVED
+ KEY_RESERVED + KEY_RESERVED + BTN_LEFT>;
to the device tree fixes exactly that, and hence the current logic in the driver is fine for detecting the touchpad.
I'll submit another patch to add this to the device tree rather than this misunderstood patch.
Quoted 1 line
Reviewed-by Nick Dyer <[email protected]>
Thank you for the review, and sorry about the noise.
/Emil