HID: haptic: introduce hid_haptic_device

Define a new structure that contains simple haptic device configuration
as well as current state.
Add functions that recognize auto trigger and manual trigger reports
as well as save their addresses.
Verify that the pressure unit is either grams or newtons.
Mark the input device as a haptic touchpad if the unit is correct and
the reports are found.

Signed-off-by: Angela Czubak <aczubak@google.com>
Co-developed-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 79997553d8f9871c6f0402c9199b453e6fea8828..8b7a2b9e800cf835feea4a9ab690a681ffd50037 100644 (file)
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -92,6 +92,17 @@ config HID_GENERIC
 
        If unsure, say Y.
 
+config HID_HAPTIC
+       tristate "Haptic touchpad support"
+       default n
+       help
+       Support for touchpads with force sensors and haptic actuators instead of a
+       traditional button.
+       Adds extra parsing and FF device for the hid multitouch driver.
+       It can be used for Elan 2703 haptic touchpad.
+
+       If unsure, say N.
+
 menu "Special HID drivers"
 
 config HID_A4TECH

diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 10ae5dedbd84708d988ea1f594d409ccebd85ebb..361a7daedeb85454114def8afb5f58caeab58a00 100644 (file)
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -4,6 +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
 
 obj-$(CONFIG_HID_BPF)          += bpf/
 

diff --git a/drivers/hid/hid-haptic.c b/drivers/hid/hid-haptic.c
new file mode 100644 (file)
index 0000000..d659a43
--- /dev/null
+++ b/drivers/hid/hid-haptic.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID Haptic support for Linux
+ *
+ *  Copyright (c) 2021 Angela Czubak <acz@semihalf.com>
+ */
+
+#include "hid-haptic.h"
+
+void hid_haptic_feature_mapping(struct hid_device *hdev,
+                               struct hid_haptic_device *haptic,
+                               struct hid_field *field, struct hid_usage *usage)
+{
+       if (usage->hid == HID_HP_AUTOTRIGGER) {
+               if (usage->usage_index >= field->report_count) {
+                       dev_err(&hdev->dev,
+                               "HID_HP_AUTOTRIGGER out of range\n");
+                       return;
+               }
+
+               hid_device_io_start(hdev);
+               hid_hw_request(hdev, field->report, HID_REQ_GET_REPORT);
+               hid_hw_wait(hdev);
+               hid_device_io_stop(hdev);
+               haptic->default_auto_trigger =
+                       field->value[usage->usage_index];
+               haptic->auto_trigger_report = field->report;
+       }
+}
+EXPORT_SYMBOL_GPL(hid_haptic_feature_mapping);
+
+bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+                                   struct hid_input *hi, struct hid_field *field)
+{
+       if (field->unit == HID_UNIT_GRAM || field->unit == HID_UNIT_NEWTON)
+               return true;
+       return false;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_check_pressure_unit);
+
+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)
+{
+       if (usage->hid == HID_HP_MANUALTRIGGER) {
+               haptic->manual_trigger_report = field->report;
+               /* we don't really want to map these fields */
+               return -1;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_mapping);
+
+int hid_haptic_input_configured(struct hid_device *hdev,
+                               struct hid_haptic_device *haptic,
+                               struct hid_input *hi)
+{
+
+       if (hi->application == HID_DG_TOUCHPAD) {
+               if (haptic->auto_trigger_report &&
+                   haptic->manual_trigger_report) {
+                       __set_bit(INPUT_PROP_HAPTIC_TOUCHPAD, hi->input->propbit);
+                       return 1;
+               }
+               return 0;
+       }
+       return -1;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_configured);

diff --git a/drivers/hid/hid-haptic.h b/drivers/hid/hid-haptic.h
new file mode 100644 (file)
index 0000000..2e89add
--- /dev/null
+++ b/drivers/hid/hid-haptic.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  HID Haptic support for Linux
+ *
+ *  Copyright (c) 2021 Angela Czubak <acz@semihalf.com>
+ */
+
+#include <linux/hid.h>
+
+#define HID_HAPTIC_ORDINAL_WAVEFORMNONE 1
+#define HID_HAPTIC_ORDINAL_WAVEFORMSTOP 2
+
+#define HID_HAPTIC_MODE_DEVICE 0
+#define HID_HAPTIC_MODE_HOST 1
+
+struct hid_haptic_effect {
+       u8 *report_buf;
+       struct input_dev *input_dev;
+       struct work_struct work;
+       struct list_head control;
+       struct mutex control_mutex;
+};
+
+struct hid_haptic_effect_node {
+       struct list_head node;
+       struct file *file;
+};
+
+struct hid_haptic_device {
+       struct input_dev *input_dev;
+       struct hid_device *hdev;
+       struct hid_report *auto_trigger_report;
+       struct mutex auto_trigger_mutex;
+       struct workqueue_struct *wq;
+       struct hid_report *manual_trigger_report;
+       struct mutex manual_trigger_mutex;
+       size_t manual_trigger_report_len;
+       int pressed_state;
+       s32 pressure_sum;
+       s32 force_logical_minimum;
+       s32 force_physical_minimum;
+       s32 force_resolution;
+       u32 mode;
+       u32 default_auto_trigger;
+       u32 vendor_page;
+       u32 vendor_id;
+       u32 max_waveform_id;
+       u32 max_duration_id;
+       u16 *hid_usage_map;
+       u32 *duration_map;
+       u16 press_ordinal;
+       u16 release_ordinal;
+       struct hid_haptic_effect *effect;
+       struct hid_haptic_effect stop_effect;
+};
+
+#if IS_ENABLED(CONFIG_HID_HAPTIC)
+void hid_haptic_feature_mapping(struct hid_device *hdev,
+                               struct hid_haptic_device *haptic,
+                               struct hid_field *field, struct hid_usage
+                               *usage);
+bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+                                   struct hid_input *hi, struct hid_field *field);
+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);
+int hid_haptic_input_configured(struct hid_device *hdev,
+                               struct hid_haptic_device *haptic,
+                               struct hid_input *hi);
+#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;
+}
+#endif