From: Angela Czubak <aczubak@google.com>
Add new option (MULTITOUCH_HAPTIC) to mark whether hid-multitouch
should try and configure simple haptic device.
Once this option is configured, and the device is recognized to have simple
haptic capabilities, check input frames for pressure and handle it using
hid_haptic_* API.
Signed-off-by: Angela Czubak <aczubak@google.com>
Co-developed-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Jonathan Denose <jdenose@google.com>
---
drivers/hid/Kconfig | 11 ++++
drivers/hid/Makefile | 2 +-
drivers/hid/hid-haptic.h | 52 +++++++++++++++++
drivers/hid/hid-multitouch.c | 136 ++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 199 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index ad6bcc4248cc111705d7cfde2b1481b46353e2d7..b7452f11a4f914f92af582ed054d42ecbcd6cb9e 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -817,6 +817,17 @@ config HID_MULTITOUCH
To compile this driver as a module, choose M here: the
module will be called hid-multitouch.
+config MULTITOUCH_HAPTIC
+ bool "Simple haptic multitouch support"
+ depends on HID_MULTITOUCH
+ select HID_HAPTIC
+ default n
+ help
+ Support for simple multitouch haptic devices.
+ Adds extra parsing and FF device for the hid multitouch driver.
+ It can be used for Elan 2703 haptic touchpad.
+ To enable, say Y.
+
config HID_NINTENDO
tristate "Nintendo Joy-Con, NSO, and Pro Controller support"
depends on NEW_LEDS
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 361a7daedeb85454114def8afb5f58caeab58a00..be09b4f13b2058a0a1d7eab79f35def758120fc4 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -4,7 +4,7 @@
#
hid-y := hid-core.o hid-input.o hid-quirks.o
hid-$(CONFIG_DEBUG_FS) += hid-debug.o
-hid-$(CONFIG_HID_HAPTIC) += hid-haptic.o
+hid-$(CONFIG_MULTITOUCH_HAPTIC) += hid-haptic.o
obj-$(CONFIG_HID_BPF) += bpf/
diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
index 0a34b0c6d706a985630962acc41f7a8eb73cd343..808cec0b4e51eba1f58b839f3e552493655b7899 100644
--- a/drivers/hid/hid-haptic.h
+++ b/drivers/hid/hid-haptic.h
@@ -58,6 +58,7 @@ struct hid_haptic_device {
struct hid_haptic_effect stop_effect;
};
+#ifdef CONFIG_MULTITOUCH_HAPTIC
void hid_haptic_feature_mapping(struct hid_device *hdev,
struct hid_haptic_device *haptic,
struct hid_field *field, struct hid_usage
@@ -77,3 +78,54 @@ void hid_haptic_handle_press_release(struct hid_haptic_device *haptic);
void hid_haptic_pressure_reset(struct hid_haptic_device *haptic);
void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
__s32 pressure);
+#else
+static inline
+void hid_haptic_feature_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_field *field, struct hid_usage
+ *usage)
+{}
+static inline
+bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+ struct hid_input *hi, struct hid_field *field)
+{
+ return false;
+}
+static inline
+int hid_haptic_input_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ return 0;
+}
+static inline
+int hid_haptic_input_configured(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi)
+{
+ return 0;
+}
+static inline
+void hid_haptic_reset(struct hid_device *hdev, struct hid_haptic_device *haptic)
+{}
+static inline
+int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device **haptic_ptr)
+{
+ return 0;
+}
+static inline
+void hid_haptic_handle_press_release(struct hid_haptic_device *haptic) {}
+static inline
+bool hid_haptic_handle_input(struct hid_haptic_device *haptic)
+{
+ return false;
+}
+static inline
+void hid_haptic_pressure_reset(struct hid_haptic_device *haptic) {}
+static inline
+void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
+ __s32 pressure)
+{}
+#endif
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index b41001e02da7e02d492bd85743b359ed7ec16e7f..4ff9ac5022b13a0739dbc7ae5f6ebd84f0114a73 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -49,6 +49,8 @@ MODULE_LICENSE("GPL");
#include "hid-ids.h"
+#include "hid-haptic.h"
+
/* quirks to control the device */
#define MT_QUIRK_NOT_SEEN_MEANS_UP BIT(0)
#define MT_QUIRK_SLOT_IS_CONTACTID BIT(1)
@@ -167,11 +169,13 @@ struct mt_report_data {
struct mt_device {
struct mt_class mtclass; /* our mt device class */
struct timer_list release_timer; /* to release sticky fingers */
+ struct hid_haptic_device *haptic; /* haptic related configuration */
struct hid_device *hdev; /* hid_device we're attached to */
unsigned long mt_io_flags; /* mt flags (MT_IO_FLAGS_*) */
__u8 inputmode_value; /* InputMode HID feature value */
__u8 maxcontacts;
bool is_buttonpad; /* is this device a button pad? */
+ bool is_haptic_touchpad; /* is this device a haptic touchpad? */
bool serial_maybe; /* need to check for serial protocol */
struct list_head applications;
@@ -490,6 +494,95 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
kfree(buf);
}
+#if defined(CONFIG_MULTITOUCH_HAPTIC)
+static int mt_haptic_init(struct hid_device *hdev,
+ struct hid_haptic_device **haptic_ptr)
+{
+ return hid_haptic_init(hdev, haptic_ptr);
+}
+
+static void mt_haptic_feature_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_field *field, struct hid_usage *usage)
+{
+ return hid_haptic_feature_mapping(hdev, haptic, field, usage);
+}
+
+static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+ struct hid_input *hi, struct hid_field *field)
+{
+ return hid_haptic_check_pressure_unit(haptic, hi, field);
+}
+
+static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
+{
+ return hid_haptic_pressure_reset(haptic);
+}
+
+static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
+ __s32 pressure)
+{
+ return hid_haptic_pressure_increase(haptic, pressure);
+}
+
+static int mt_haptic_input_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ return hid_haptic_input_mapping(hdev, haptic, hi, field, usage, bit, max);
+}
+
+static int mt_haptic_input_configured(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi)
+{
+ return hid_haptic_input_configured(hdev, haptic, hi);
+}
+#else
+static int mt_haptic_init(struct hid_device *hdev,
+ struct hid_haptic_device **haptic_ptr)
+{
+ return 0;
+}
+
+static void mt_haptic_feature_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_field *field, struct hid_usage *usage)
+{}
+
+static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+ struct hid_input *hi, struct hid_field *field)
+{
+ return 0;
+}
+
+static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
+{}
+
+static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
+ __s32 pressure)
+{}
+
+static int mt_haptic_input_mapping(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ return 0;
+}
+
+static int mt_haptic_input_configured(struct hid_device *hdev,
+ struct hid_haptic_device *haptic,
+ struct hid_input *hi)
+{
+ return 0;
+}
+#endif
+
+
static void mt_feature_mapping(struct hid_device *hdev,
struct hid_field *field, struct hid_usage *usage)
{
@@ -525,6 +618,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
mt_get_feature(hdev, field->report);
break;
}
+
+ mt_haptic_feature_mapping(hdev, td->haptic, field, usage);
}
static void set_abs(struct input_dev *input, unsigned int code,
@@ -856,6 +951,9 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
case HID_DG_TIPPRESSURE:
set_abs(hi->input, ABS_MT_PRESSURE, field,
cls->sn_pressure);
+ td->is_haptic_touchpad =
+ mt_haptic_check_pressure_unit(td->haptic,
+ hi, field);
MT_STORE_FIELD(p);
return 1;
case HID_DG_SCANTIME:
@@ -980,6 +1078,8 @@ static void mt_sync_frame(struct mt_device *td, struct mt_application *app,
app->num_received = 0;
app->left_button_state = 0;
+ if (td->is_haptic_touchpad)
+ mt_haptic_pressure_reset(td->haptic);
if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags))
set_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags);
@@ -1137,6 +1237,9 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
minor = minor >> 1;
}
+ if (td->is_haptic_touchpad)
+ mt_haptic_pressure_increase(td->haptic, *slot->p);
+
x = hdev->quirks & HID_QUIRK_X_INVERT ?
input_abs_get_max(input, ABS_MT_POSITION_X) - *slot->x :
*slot->x;
@@ -1324,6 +1427,9 @@ static int mt_touch_input_configured(struct hid_device *hdev,
if (cls->is_indirect)
app->mt_flags |= INPUT_MT_POINTER;
+ if (td->is_haptic_touchpad)
+ app->mt_flags |= INPUT_MT_TOTAL_FORCE;
+
if (app->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
app->mt_flags |= INPUT_MT_DROP_UNUSED;
@@ -1359,6 +1465,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
struct mt_device *td = hid_get_drvdata(hdev);
struct mt_application *application;
struct mt_report_data *rdata;
+ int ret;
rdata = mt_find_report_data(td, field->report);
if (!rdata) {
@@ -1421,6 +1528,11 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
if (field->physical == HID_DG_STYLUS)
hi->application = HID_DG_STYLUS;
+ ret = mt_haptic_input_mapping(hdev, td->haptic, hi, field, usage, bit,
+ max);
+ if (ret != 0)
+ return ret;
+
/* let hid-core decide for the others */
return 0;
}
@@ -1635,6 +1747,14 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
struct hid_report *report;
int ret;
+ if (td->is_haptic_touchpad && (td->mtclass.name == MT_CLS_WIN_8 ||
+ td->mtclass.name == MT_CLS_WIN_8_FORCE_MULTI_INPUT)) {
+ if (mt_haptic_input_configured(hdev, td->haptic, hi) == 0)
+ td->is_haptic_touchpad = false;
+ } else {
+ td->is_haptic_touchpad = false;
+ }
+
list_for_each_entry(report, &hi->reports, hidinput_list) {
rdata = mt_find_report_data(td, report);
if (!rdata) {
@@ -1764,7 +1884,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
int ret, i;
struct mt_device *td;
const struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
-
for (i = 0; mt_classes[i].name ; i++) {
if (id->driver_data == mt_classes[i].name) {
mtclass = &(mt_classes[i]);
@@ -1777,6 +1896,10 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
dev_err(&hdev->dev, "cannot allocate multitouch data\n");
return -ENOMEM;
}
+ td->haptic = kzalloc(sizeof(*(td->haptic)), GFP_KERNEL);
+ if (!td->haptic)
+ return -ENOMEM;
+ td->haptic->hdev = hdev;
td->hdev = hdev;
td->mtclass = *mtclass;
td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
@@ -1840,6 +1963,17 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
+ if (td->is_haptic_touchpad) {
+ if (mt_haptic_init(hdev, &td->haptic)) {
+ dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
+ hdev->name);
+ td->is_haptic_touchpad = false;
+ kfree(td->haptic);
+ }
+ } else {
+ kfree(td->haptic);
+ }
+
return 0;
}
--
2.50.1.565.gc32cd1483b-googOn Aug 04 2025, Jonathan Denose wrote:
> From: Angela Czubak <aczubak@google.com>
>
> Add new option (MULTITOUCH_HAPTIC) to mark whether hid-multitouch
> should try and configure simple haptic device.
> Once this option is configured, and the device is recognized to have simple
> haptic capabilities, check input frames for pressure and handle it using
> hid_haptic_* API.
Why creating a new option? It seems it'll add unwanted work from
distributions when we should have something that "just works" no?
It makes sense to depend on FF, but adding a new option is probably
useless IMO.
>
> Signed-off-by: Angela Czubak <aczubak@google.com>
> Co-developed-by: Jonathan Denose <jdenose@google.com>
> Signed-off-by: Jonathan Denose <jdenose@google.com>
> ---
> drivers/hid/Kconfig | 11 ++++
> drivers/hid/Makefile | 2 +-
> drivers/hid/hid-haptic.h | 52 +++++++++++++++++
> drivers/hid/hid-multitouch.c | 136 ++++++++++++++++++++++++++++++++++++++++++-
> 4 files changed, 199 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index ad6bcc4248cc111705d7cfde2b1481b46353e2d7..b7452f11a4f914f92af582ed054d42ecbcd6cb9e 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -817,6 +817,17 @@ config HID_MULTITOUCH
> To compile this driver as a module, choose M here: the
> module will be called hid-multitouch.
>
> +config MULTITOUCH_HAPTIC
> + bool "Simple haptic multitouch support"
> + depends on HID_MULTITOUCH
> + select HID_HAPTIC
> + default n
> + help
> + Support for simple multitouch haptic devices.
> + Adds extra parsing and FF device for the hid multitouch driver.
> + It can be used for Elan 2703 haptic touchpad.
> + To enable, say Y.
> +
> config HID_NINTENDO
> tristate "Nintendo Joy-Con, NSO, and Pro Controller support"
> depends on NEW_LEDS
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index 361a7daedeb85454114def8afb5f58caeab58a00..be09b4f13b2058a0a1d7eab79f35def758120fc4 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -4,7 +4,7 @@
> #
> hid-y := hid-core.o hid-input.o hid-quirks.o
> hid-$(CONFIG_DEBUG_FS) += hid-debug.o
> -hid-$(CONFIG_HID_HAPTIC) += hid-haptic.o
> +hid-$(CONFIG_MULTITOUCH_HAPTIC) += hid-haptic.o
>
> obj-$(CONFIG_HID_BPF) += bpf/
>
> diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
> index 0a34b0c6d706a985630962acc41f7a8eb73cd343..808cec0b4e51eba1f58b839f3e552493655b7899 100644
> --- a/drivers/hid/hid-haptic.h
> +++ b/drivers/hid/hid-haptic.h
> @@ -58,6 +58,7 @@ struct hid_haptic_device {
> struct hid_haptic_effect stop_effect;
> };
>
> +#ifdef CONFIG_MULTITOUCH_HAPTIC
There is something wrong with your ifdef usages:
- here, you define the functions below conditionally to
CONFIG_MULTITOUCH_HAPTIC, which is fine
- but in hid-multitouch, you also check for CONFIG_MULTITOUCH_HAPTIC
before calling the same set of functions.
Either only define the haptic functions when CONFIG_MULTITOUCH_HAPTIC is
set, and in multitouch check for that define, or define it conditionally
and remove the checks in hid-multitouch (but probably add a comment).
> void hid_haptic_feature_mapping(struct hid_device *hdev,
> struct hid_haptic_device *haptic,
> struct hid_field *field, struct hid_usage
> @@ -77,3 +78,54 @@ void hid_haptic_handle_press_release(struct hid_haptic_device *haptic);
> void hid_haptic_pressure_reset(struct hid_haptic_device *haptic);
> void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
> __s32 pressure);
> +#else
> +static inline
> +void hid_haptic_feature_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_field *field, struct hid_usage
> + *usage)
> +{}
> +static inline
> +bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> + struct hid_input *hi, struct hid_field *field)
> +{
> + return false;
> +}
> +static inline
> +int hid_haptic_input_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi,
> + struct hid_field *field, struct hid_usage *usage,
> + unsigned long **bit, int *max)
> +{
> + return 0;
> +}
> +static inline
> +int hid_haptic_input_configured(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi)
> +{
> + return 0;
> +}
> +static inline
> +void hid_haptic_reset(struct hid_device *hdev, struct hid_haptic_device *haptic)
> +{}
> +static inline
> +int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device **haptic_ptr)
> +{
> + return 0;
> +}
> +static inline
> +void hid_haptic_handle_press_release(struct hid_haptic_device *haptic) {}
> +static inline
> +bool hid_haptic_handle_input(struct hid_haptic_device *haptic)
> +{
> + return false;
> +}
> +static inline
> +void hid_haptic_pressure_reset(struct hid_haptic_device *haptic) {}
> +static inline
> +void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
> + __s32 pressure)
> +{}
> +#endif
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index b41001e02da7e02d492bd85743b359ed7ec16e7f..4ff9ac5022b13a0739dbc7ae5f6ebd84f0114a73 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -49,6 +49,8 @@ MODULE_LICENSE("GPL");
>
> #include "hid-ids.h"
>
> +#include "hid-haptic.h"
> +
> /* quirks to control the device */
> #define MT_QUIRK_NOT_SEEN_MEANS_UP BIT(0)
> #define MT_QUIRK_SLOT_IS_CONTACTID BIT(1)
> @@ -167,11 +169,13 @@ struct mt_report_data {
> struct mt_device {
> struct mt_class mtclass; /* our mt device class */
> struct timer_list release_timer; /* to release sticky fingers */
> + struct hid_haptic_device *haptic; /* haptic related configuration */
> struct hid_device *hdev; /* hid_device we're attached to */
> unsigned long mt_io_flags; /* mt flags (MT_IO_FLAGS_*) */
> __u8 inputmode_value; /* InputMode HID feature value */
> __u8 maxcontacts;
> bool is_buttonpad; /* is this device a button pad? */
> + bool is_haptic_touchpad; /* is this device a haptic touchpad? */
> bool serial_maybe; /* need to check for serial protocol */
>
> struct list_head applications;
> @@ -490,6 +494,95 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
> kfree(buf);
> }
>
> +#if defined(CONFIG_MULTITOUCH_HAPTIC)
> +static int mt_haptic_init(struct hid_device *hdev,
> + struct hid_haptic_device **haptic_ptr)
> +{
> + return hid_haptic_init(hdev, haptic_ptr);
> +}
> +
> +static void mt_haptic_feature_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_field *field, struct hid_usage *usage)
> +{
> + return hid_haptic_feature_mapping(hdev, haptic, field, usage);
> +}
> +
> +static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> + struct hid_input *hi, struct hid_field *field)
> +{
> + return hid_haptic_check_pressure_unit(haptic, hi, field);
> +}
> +
> +static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
> +{
> + return hid_haptic_pressure_reset(haptic);
> +}
> +
> +static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
> + __s32 pressure)
> +{
> + return hid_haptic_pressure_increase(haptic, pressure);
> +}
> +
> +static int mt_haptic_input_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi,
> + struct hid_field *field, struct hid_usage *usage,
> + unsigned long **bit, int *max)
> +{
> + return hid_haptic_input_mapping(hdev, haptic, hi, field, usage, bit, max);
> +}
> +
> +static int mt_haptic_input_configured(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi)
> +{
> + return hid_haptic_input_configured(hdev, haptic, hi);
> +}
> +#else
> +static int mt_haptic_init(struct hid_device *hdev,
> + struct hid_haptic_device **haptic_ptr)
> +{
> + return 0;
> +}
> +
> +static void mt_haptic_feature_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_field *field, struct hid_usage *usage)
> +{}
> +
> +static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> + struct hid_input *hi, struct hid_field *field)
> +{
> + return 0;
> +}
> +
> +static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
> +{}
> +
> +static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
> + __s32 pressure)
> +{}
> +
> +static int mt_haptic_input_mapping(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi,
> + struct hid_field *field, struct hid_usage *usage,
> + unsigned long **bit, int *max)
> +{
> + return 0;
> +}
> +
> +static int mt_haptic_input_configured(struct hid_device *hdev,
> + struct hid_haptic_device *haptic,
> + struct hid_input *hi)
> +{
> + return 0;
> +}
> +#endif
> +
> +
> static void mt_feature_mapping(struct hid_device *hdev,
> struct hid_field *field, struct hid_usage *usage)
> {
> @@ -525,6 +618,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
> mt_get_feature(hdev, field->report);
> break;
> }
> +
> + mt_haptic_feature_mapping(hdev, td->haptic, field, usage);
> }
>
> static void set_abs(struct input_dev *input, unsigned int code,
> @@ -856,6 +951,9 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> case HID_DG_TIPPRESSURE:
> set_abs(hi->input, ABS_MT_PRESSURE, field,
> cls->sn_pressure);
> + td->is_haptic_touchpad =
> + mt_haptic_check_pressure_unit(td->haptic,
> + hi, field);
> MT_STORE_FIELD(p);
> return 1;
> case HID_DG_SCANTIME:
> @@ -980,6 +1078,8 @@ static void mt_sync_frame(struct mt_device *td, struct mt_application *app,
>
> app->num_received = 0;
> app->left_button_state = 0;
> + if (td->is_haptic_touchpad)
> + mt_haptic_pressure_reset(td->haptic);
>
> if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags))
> set_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags);
> @@ -1137,6 +1237,9 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
> minor = minor >> 1;
> }
>
> + if (td->is_haptic_touchpad)
> + mt_haptic_pressure_increase(td->haptic, *slot->p);
> +
> x = hdev->quirks & HID_QUIRK_X_INVERT ?
> input_abs_get_max(input, ABS_MT_POSITION_X) - *slot->x :
> *slot->x;
> @@ -1324,6 +1427,9 @@ static int mt_touch_input_configured(struct hid_device *hdev,
> if (cls->is_indirect)
> app->mt_flags |= INPUT_MT_POINTER;
>
> + if (td->is_haptic_touchpad)
> + app->mt_flags |= INPUT_MT_TOTAL_FORCE;
> +
> if (app->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
> app->mt_flags |= INPUT_MT_DROP_UNUSED;
>
> @@ -1359,6 +1465,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> struct mt_device *td = hid_get_drvdata(hdev);
> struct mt_application *application;
> struct mt_report_data *rdata;
> + int ret;
>
> rdata = mt_find_report_data(td, field->report);
> if (!rdata) {
> @@ -1421,6 +1528,11 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> if (field->physical == HID_DG_STYLUS)
> hi->application = HID_DG_STYLUS;
>
> + ret = mt_haptic_input_mapping(hdev, td->haptic, hi, field, usage, bit,
> + max);
> + if (ret != 0)
> + return ret;
> +
> /* let hid-core decide for the others */
> return 0;
> }
> @@ -1635,6 +1747,14 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
> struct hid_report *report;
> int ret;
>
> + if (td->is_haptic_touchpad && (td->mtclass.name == MT_CLS_WIN_8 ||
> + td->mtclass.name == MT_CLS_WIN_8_FORCE_MULTI_INPUT)) {
> + if (mt_haptic_input_configured(hdev, td->haptic, hi) == 0)
> + td->is_haptic_touchpad = false;
> + } else {
> + td->is_haptic_touchpad = false;
> + }
> +
> list_for_each_entry(report, &hi->reports, hidinput_list) {
> rdata = mt_find_report_data(td, report);
> if (!rdata) {
> @@ -1764,7 +1884,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> int ret, i;
> struct mt_device *td;
> const struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
> -
unrelated change (line removed).
> for (i = 0; mt_classes[i].name ; i++) {
> if (id->driver_data == mt_classes[i].name) {
> mtclass = &(mt_classes[i]);
> @@ -1777,6 +1896,10 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> dev_err(&hdev->dev, "cannot allocate multitouch data\n");
> return -ENOMEM;
> }
> + td->haptic = kzalloc(sizeof(*(td->haptic)), GFP_KERNEL);
Please make use of the devm api, you are leaking the allocated memory in
the regular case (AFAICT).
> + if (!td->haptic)
> + return -ENOMEM;
One extra blank line wouldn't hurt here :)
> + td->haptic->hdev = hdev;
> td->hdev = hdev;
> td->mtclass = *mtclass;
> td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
> @@ -1840,6 +1963,17 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>
> mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
>
> + if (td->is_haptic_touchpad) {
> + if (mt_haptic_init(hdev, &td->haptic)) {
> + dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
> + hdev->name);
> + td->is_haptic_touchpad = false;
> + kfree(td->haptic);
> + }
> + } else {
> + kfree(td->haptic);
> + }
> +
> return 0;
> }
>
>
> --
> 2.50.1.565.gc32cd1483b-goog
>
Cheers,
Benjamin
On Wed, Aug 13, 2025 at 4:22 AM Benjamin Tissoires <bentiss@kernel.org> wrote:
>
> On Aug 04 2025, Jonathan Denose wrote:
> > From: Angela Czubak <aczubak@google.com>
> >
> > Add new option (MULTITOUCH_HAPTIC) to mark whether hid-multitouch
> > should try and configure simple haptic device.
> > Once this option is configured, and the device is recognized to have simple
> > haptic capabilities, check input frames for pressure and handle it using
> > hid_haptic_* API.
>
> Why creating a new option? It seems it'll add unwanted work from
> distributions when we should have something that "just works" no?
>
> It makes sense to depend on FF, but adding a new option is probably
> useless IMO.
>
> >
> > Signed-off-by: Angela Czubak <aczubak@google.com>
> > Co-developed-by: Jonathan Denose <jdenose@google.com>
> > Signed-off-by: Jonathan Denose <jdenose@google.com>
> > ---
> > drivers/hid/Kconfig | 11 ++++
> > drivers/hid/Makefile | 2 +-
> > drivers/hid/hid-haptic.h | 52 +++++++++++++++++
> > drivers/hid/hid-multitouch.c | 136 ++++++++++++++++++++++++++++++++++++++++++-
> > 4 files changed, 199 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> > index ad6bcc4248cc111705d7cfde2b1481b46353e2d7..b7452f11a4f914f92af582ed054d42ecbcd6cb9e 100644
> > --- a/drivers/hid/Kconfig
> > +++ b/drivers/hid/Kconfig
> > @@ -817,6 +817,17 @@ config HID_MULTITOUCH
> > To compile this driver as a module, choose M here: the
> > module will be called hid-multitouch.
> >
> > +config MULTITOUCH_HAPTIC
> > + bool "Simple haptic multitouch support"
> > + depends on HID_MULTITOUCH
> > + select HID_HAPTIC
> > + default n
> > + help
> > + Support for simple multitouch haptic devices.
> > + Adds extra parsing and FF device for the hid multitouch driver.
> > + It can be used for Elan 2703 haptic touchpad.
> > + To enable, say Y.
> > +
> > config HID_NINTENDO
> > tristate "Nintendo Joy-Con, NSO, and Pro Controller support"
> > depends on NEW_LEDS
> > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> > index 361a7daedeb85454114def8afb5f58caeab58a00..be09b4f13b2058a0a1d7eab79f35def758120fc4 100644
> > --- a/drivers/hid/Makefile
> > +++ b/drivers/hid/Makefile
> > @@ -4,7 +4,7 @@
> > #
> > hid-y := hid-core.o hid-input.o hid-quirks.o
> > hid-$(CONFIG_DEBUG_FS) += hid-debug.o
> > -hid-$(CONFIG_HID_HAPTIC) += hid-haptic.o
> > +hid-$(CONFIG_MULTITOUCH_HAPTIC) += hid-haptic.o
> >
> > obj-$(CONFIG_HID_BPF) += bpf/
> >
> > diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
> > index 0a34b0c6d706a985630962acc41f7a8eb73cd343..808cec0b4e51eba1f58b839f3e552493655b7899 100644
> > --- a/drivers/hid/hid-haptic.h
> > +++ b/drivers/hid/hid-haptic.h
> > @@ -58,6 +58,7 @@ struct hid_haptic_device {
> > struct hid_haptic_effect stop_effect;
> > };
> >
> > +#ifdef CONFIG_MULTITOUCH_HAPTIC
>
> There is something wrong with your ifdef usages:
> - here, you define the functions below conditionally to
> CONFIG_MULTITOUCH_HAPTIC, which is fine
> - but in hid-multitouch, you also check for CONFIG_MULTITOUCH_HAPTIC
> before calling the same set of functions.
>
> Either only define the haptic functions when CONFIG_MULTITOUCH_HAPTIC is
> set, and in multitouch check for that define, or define it conditionally
> and remove the checks in hid-multitouch (but probably add a comment).
> > void hid_haptic_feature_mapping(struct hid_device *hdev,
> > struct hid_haptic_device *haptic,
> > struct hid_field *field, struct hid_usage
> > @@ -77,3 +78,54 @@ void hid_haptic_handle_press_release(struct hid_haptic_device *haptic);
> > void hid_haptic_pressure_reset(struct hid_haptic_device *haptic);
> > void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
> > __s32 pressure);
> > +#else
> > +static inline
> > +void hid_haptic_feature_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_field *field, struct hid_usage
> > + *usage)
> > +{}
> > +static inline
> > +bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> > + struct hid_input *hi, struct hid_field *field)
> > +{
> > + return false;
> > +}
> > +static inline
> > +int hid_haptic_input_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi,
> > + struct hid_field *field, struct hid_usage *usage,
> > + unsigned long **bit, int *max)
> > +{
> > + return 0;
> > +}
> > +static inline
> > +int hid_haptic_input_configured(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi)
> > +{
> > + return 0;
> > +}
> > +static inline
> > +void hid_haptic_reset(struct hid_device *hdev, struct hid_haptic_device *haptic)
> > +{}
> > +static inline
> > +int hid_haptic_init(struct hid_device *hdev, struct hid_haptic_device **haptic_ptr)
> > +{
> > + return 0;
> > +}
> > +static inline
> > +void hid_haptic_handle_press_release(struct hid_haptic_device *haptic) {}
> > +static inline
> > +bool hid_haptic_handle_input(struct hid_haptic_device *haptic)
> > +{
> > + return false;
> > +}
> > +static inline
> > +void hid_haptic_pressure_reset(struct hid_haptic_device *haptic) {}
> > +static inline
> > +void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
> > + __s32 pressure)
> > +{}
> > +#endif
> > diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> > index b41001e02da7e02d492bd85743b359ed7ec16e7f..4ff9ac5022b13a0739dbc7ae5f6ebd84f0114a73 100644
> > --- a/drivers/hid/hid-multitouch.c
> > +++ b/drivers/hid/hid-multitouch.c
> > @@ -49,6 +49,8 @@ MODULE_LICENSE("GPL");
> >
> > #include "hid-ids.h"
> >
> > +#include "hid-haptic.h"
> > +
> > /* quirks to control the device */
> > #define MT_QUIRK_NOT_SEEN_MEANS_UP BIT(0)
> > #define MT_QUIRK_SLOT_IS_CONTACTID BIT(1)
> > @@ -167,11 +169,13 @@ struct mt_report_data {
> > struct mt_device {
> > struct mt_class mtclass; /* our mt device class */
> > struct timer_list release_timer; /* to release sticky fingers */
> > + struct hid_haptic_device *haptic; /* haptic related configuration */
> > struct hid_device *hdev; /* hid_device we're attached to */
> > unsigned long mt_io_flags; /* mt flags (MT_IO_FLAGS_*) */
> > __u8 inputmode_value; /* InputMode HID feature value */
> > __u8 maxcontacts;
> > bool is_buttonpad; /* is this device a button pad? */
> > + bool is_haptic_touchpad; /* is this device a haptic touchpad? */
> > bool serial_maybe; /* need to check for serial protocol */
> >
> > struct list_head applications;
> > @@ -490,6 +494,95 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
> > kfree(buf);
> > }
> >
> > +#if defined(CONFIG_MULTITOUCH_HAPTIC)
> > +static int mt_haptic_init(struct hid_device *hdev,
> > + struct hid_haptic_device **haptic_ptr)
> > +{
> > + return hid_haptic_init(hdev, haptic_ptr);
> > +}
> > +
> > +static void mt_haptic_feature_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_field *field, struct hid_usage *usage)
> > +{
> > + return hid_haptic_feature_mapping(hdev, haptic, field, usage);
> > +}
> > +
> > +static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> > + struct hid_input *hi, struct hid_field *field)
> > +{
> > + return hid_haptic_check_pressure_unit(haptic, hi, field);
> > +}
> > +
> > +static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
> > +{
> > + return hid_haptic_pressure_reset(haptic);
> > +}
> > +
> > +static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
> > + __s32 pressure)
> > +{
> > + return hid_haptic_pressure_increase(haptic, pressure);
> > +}
> > +
> > +static int mt_haptic_input_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi,
> > + struct hid_field *field, struct hid_usage *usage,
> > + unsigned long **bit, int *max)
> > +{
> > + return hid_haptic_input_mapping(hdev, haptic, hi, field, usage, bit, max);
> > +}
> > +
> > +static int mt_haptic_input_configured(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi)
> > +{
> > + return hid_haptic_input_configured(hdev, haptic, hi);
> > +}
> > +#else
> > +static int mt_haptic_init(struct hid_device *hdev,
> > + struct hid_haptic_device **haptic_ptr)
> > +{
> > + return 0;
> > +}
> > +
> > +static void mt_haptic_feature_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_field *field, struct hid_usage *usage)
> > +{}
> > +
> > +static bool mt_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
> > + struct hid_input *hi, struct hid_field *field)
> > +{
> > + return 0;
> > +}
> > +
> > +static void mt_haptic_pressure_reset(struct hid_haptic_device *haptic)
> > +{}
> > +
> > +static void mt_haptic_pressure_increase(struct hid_haptic_device *haptic,
> > + __s32 pressure)
> > +{}
> > +
> > +static int mt_haptic_input_mapping(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi,
> > + struct hid_field *field, struct hid_usage *usage,
> > + unsigned long **bit, int *max)
> > +{
> > + return 0;
> > +}
> > +
> > +static int mt_haptic_input_configured(struct hid_device *hdev,
> > + struct hid_haptic_device *haptic,
> > + struct hid_input *hi)
> > +{
> > + return 0;
> > +}
> > +#endif
> > +
> > +
> > static void mt_feature_mapping(struct hid_device *hdev,
> > struct hid_field *field, struct hid_usage *usage)
> > {
> > @@ -525,6 +618,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
> > mt_get_feature(hdev, field->report);
> > break;
> > }
> > +
> > + mt_haptic_feature_mapping(hdev, td->haptic, field, usage);
> > }
> >
> > static void set_abs(struct input_dev *input, unsigned int code,
> > @@ -856,6 +951,9 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> > case HID_DG_TIPPRESSURE:
> > set_abs(hi->input, ABS_MT_PRESSURE, field,
> > cls->sn_pressure);
> > + td->is_haptic_touchpad =
> > + mt_haptic_check_pressure_unit(td->haptic,
> > + hi, field);
> > MT_STORE_FIELD(p);
> > return 1;
> > case HID_DG_SCANTIME:
> > @@ -980,6 +1078,8 @@ static void mt_sync_frame(struct mt_device *td, struct mt_application *app,
> >
> > app->num_received = 0;
> > app->left_button_state = 0;
> > + if (td->is_haptic_touchpad)
> > + mt_haptic_pressure_reset(td->haptic);
> >
> > if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags))
> > set_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags);
> > @@ -1137,6 +1237,9 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
> > minor = minor >> 1;
> > }
> >
> > + if (td->is_haptic_touchpad)
> > + mt_haptic_pressure_increase(td->haptic, *slot->p);
> > +
> > x = hdev->quirks & HID_QUIRK_X_INVERT ?
> > input_abs_get_max(input, ABS_MT_POSITION_X) - *slot->x :
> > *slot->x;
> > @@ -1324,6 +1427,9 @@ static int mt_touch_input_configured(struct hid_device *hdev,
> > if (cls->is_indirect)
> > app->mt_flags |= INPUT_MT_POINTER;
> >
> > + if (td->is_haptic_touchpad)
> > + app->mt_flags |= INPUT_MT_TOTAL_FORCE;
> > +
> > if (app->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
> > app->mt_flags |= INPUT_MT_DROP_UNUSED;
> >
> > @@ -1359,6 +1465,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> > struct mt_device *td = hid_get_drvdata(hdev);
> > struct mt_application *application;
> > struct mt_report_data *rdata;
> > + int ret;
> >
> > rdata = mt_find_report_data(td, field->report);
> > if (!rdata) {
> > @@ -1421,6 +1528,11 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> > if (field->physical == HID_DG_STYLUS)
> > hi->application = HID_DG_STYLUS;
> >
> > + ret = mt_haptic_input_mapping(hdev, td->haptic, hi, field, usage, bit,
> > + max);
> > + if (ret != 0)
> > + return ret;
> > +
> > /* let hid-core decide for the others */
> > return 0;
> > }
> > @@ -1635,6 +1747,14 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
> > struct hid_report *report;
> > int ret;
> >
> > + if (td->is_haptic_touchpad && (td->mtclass.name == MT_CLS_WIN_8 ||
> > + td->mtclass.name == MT_CLS_WIN_8_FORCE_MULTI_INPUT)) {
> > + if (mt_haptic_input_configured(hdev, td->haptic, hi) == 0)
> > + td->is_haptic_touchpad = false;
> > + } else {
> > + td->is_haptic_touchpad = false;
> > + }
> > +
> > list_for_each_entry(report, &hi->reports, hidinput_list) {
> > rdata = mt_find_report_data(td, report);
> > if (!rdata) {
> > @@ -1764,7 +1884,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> > int ret, i;
> > struct mt_device *td;
> > const struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
> > -
>
> unrelated change (line removed).
>
> > for (i = 0; mt_classes[i].name ; i++) {
> > if (id->driver_data == mt_classes[i].name) {
> > mtclass = &(mt_classes[i]);
> > @@ -1777,6 +1896,10 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> > dev_err(&hdev->dev, "cannot allocate multitouch data\n");
> > return -ENOMEM;
> > }
> > + td->haptic = kzalloc(sizeof(*(td->haptic)), GFP_KERNEL);
>
> Please make use of the devm api, you are leaking the allocated memory in
> the regular case (AFAICT).
>
> > + if (!td->haptic)
> > + return -ENOMEM;
>
> One extra blank line wouldn't hurt here :)
>
> > + td->haptic->hdev = hdev;
> > td->hdev = hdev;
> > td->mtclass = *mtclass;
> > td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
> > @@ -1840,6 +1963,17 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> >
> > mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
> >
> > + if (td->is_haptic_touchpad) {
> > + if (mt_haptic_init(hdev, &td->haptic)) {
> > + dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
> > + hdev->name);
> > + td->is_haptic_touchpad = false;
> > + kfree(td->haptic);
> > + }
> > + } else {
> > + kfree(td->haptic);
> > + }
> > +
> > return 0;
> > }
> >
> >
> > --
> > 2.50.1.565.gc32cd1483b-goog
> >
>
> Cheers,
> Benjamin
I'll make the changes and send out a new version.
Thanks for your review!
--
Jonathan
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