--- /dev/null
+/*
+ * HID driver for Cando dual-touch panels
+ *
+ * Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
+ *
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
+MODULE_DESCRIPTION("Cando dual-touch panel");
+MODULE_LICENSE("GPL");
+
+#include "hid-ids.h"
+
+struct cando_data {
+ __u16 x, y;
+ __u8 id;
+ __s8 oldest; /* id of the oldest finger in previous frame */
+ bool valid; /* valid finger data, or just placeholder? */
+ bool first; /* is this the first finger in this frame? */
+ __s8 firstid; /* id of the first finger in the frame */
+ __u16 firstx, firsty; /* (x, y) of the first finger in the frame */
+};
+
+static int cando_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ switch (usage->hid & HID_USAGE_PAGE) {
+
+ case HID_UP_GENDESK:
+ switch (usage->hid) {
+ case HID_GD_X:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_POSITION_X);
+ /* touchscreen emulation */
+ input_set_abs_params(hi->input, ABS_X,
+ field->logical_minimum,
+ field->logical_maximum, 0, 0);
+ return 1;
+ case HID_GD_Y:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_POSITION_Y);
+ /* touchscreen emulation */
+ input_set_abs_params(hi->input, ABS_Y,
+ field->logical_minimum,
+ field->logical_maximum, 0, 0);
+ return 1;
+ }
+ return 0;
+
+ case HID_UP_DIGITIZER:
+ switch (usage->hid) {
+ case HID_DG_TIPSWITCH:
+ case HID_DG_CONTACTMAX:
+ return -1;
+ case HID_DG_INRANGE:
+ /* touchscreen emulation */
+ hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
+ return 1;
+ case HID_DG_CONTACTID:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_TRACKING_ID);
+ return 1;
+ }
+ return 0;
+ }
+
+ return 0;
+}
+
+static int cando_input_mapped(struct hid_device *hdev, struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ if (usage->type == EV_KEY || usage->type == EV_ABS)
+ clear_bit(usage->code, *bit);
+
+ return 0;
+}
+
+/*
+ * this function is called when a whole finger has been parsed,
+ * so that it can decide what to send to the input layer.
+ */
+static void cando_filter_event(struct cando_data *td, struct input_dev *input)
+{
+ td->first = !td->first; /* touchscreen emulation */
+
+ if (!td->valid) {
+ /*
+ * touchscreen emulation: if this is the second finger and
+ * the first was valid, the first was the oldest; if the
+ * first was not valid and there was a valid finger in the
+ * previous frame, this is a release.
+ */
+ if (td->first) {
+ td->firstid = -1;
+ } else if (td->firstid >= 0) {
+ input_event(input, EV_ABS, ABS_X, td->firstx);
+ input_event(input, EV_ABS, ABS_Y, td->firsty);
+ td->oldest = td->firstid;
+ } else if (td->oldest >= 0) {
+ input_event(input, EV_KEY, BTN_TOUCH, 0);
+ td->oldest = -1;
+ }
+
+ return;
+ }
+
+ input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
+ input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
+ input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
+
+ input_mt_sync(input);
+
+ /*
+ * touchscreen emulation: if there was no touching finger previously,
+ * emit touch event
+ */
+ if (td->oldest < 0) {
+ input_event(input, EV_KEY, BTN_TOUCH, 1);
+ td->oldest = td->id;
+ }
+
+ /*
+ * touchscreen emulation: if this is the first finger, wait for the
+ * second; the oldest is then the second if it was the oldest already
+ * or if there was no first, the first otherwise.
+ */
+ if (td->first) {
+ td->firstx = td->x;
+ td->firsty = td->y;
+ td->firstid = td->id;
+ } else {
+ int x, y, oldest;
+ if (td->id == td->oldest || td->firstid < 0) {
+ x = td->x;
+ y = td->y;
+ oldest = td->id;
+ } else {
+ x = td->firstx;
+ y = td->firsty;
+ oldest = td->firstid;
+ }
+ input_event(input, EV_ABS, ABS_X, x);
+ input_event(input, EV_ABS, ABS_Y, y);
+ td->oldest = oldest;
+ }
+}
+
+
+static int cando_event(struct hid_device *hid, struct hid_field *field,
+ struct hid_usage *usage, __s32 value)
+{
+ struct cando_data *td = hid_get_drvdata(hid);
+
+ if (hid->claimed & HID_CLAIMED_INPUT) {
+ struct input_dev *input = field->hidinput->input;
+
+ switch (usage->hid) {
+ case HID_DG_INRANGE:
+ td->valid = value;
+ break;
+ case HID_DG_CONTACTID:
+ td->id = value;
+ break;
+ case HID_GD_X:
+ td->x = value;
+ break;
+ case HID_GD_Y:
+ td->y = value;
+ cando_filter_event(td, input);
+ break;
+ case HID_DG_TIPSWITCH:
+ /* avoid interference from generic hidinput handling */
+ break;
+
+ default:
+ /* fallback to the generic hidinput handling */
+ return 0;
+ }
+ }
+
+ /* we have handled the hidinput part, now remains hiddev */
+ if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
+ hid->hiddev_hid_event(hid, field, usage, value);
+
+ return 1;
+}
+
+static int cando_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+ int ret;
+ struct cando_data *td;
+
+ td = kmalloc(sizeof(struct cando_data), GFP_KERNEL);
+ if (!td) {
+ dev_err(&hdev->dev, "cannot allocate Cando Touch data\n");
+ return -ENOMEM;
+ }
+ hid_set_drvdata(hdev, td);
+
+ ret = hid_parse(hdev);
+ if (!ret)
+ ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+
+ if (ret)
+ kfree(td);
+
+ return ret;
+}
+
+static void cando_remove(struct hid_device *hdev)
+{
+ hid_hw_stop(hdev);
+ kfree(hid_get_drvdata(hdev));
+ hid_set_drvdata(hdev, NULL);
+}
+
+static const struct hid_device_id cando_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
+ USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
+ { }
+};
+MODULE_DEVICE_TABLE(hid, cando_devices);
+
+static const struct hid_usage_id cando_grabbed_usages[] = {
+ { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
+ { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
+};
+
+static struct hid_driver cando_driver = {
+ .name = "cando-touch",
+ .id_table = cando_devices,
+ .probe = cando_probe,
+ .remove = cando_remove,
+ .input_mapping = cando_input_mapping,
+ .input_mapped = cando_input_mapped,
+ .usage_table = cando_grabbed_usages,
+ .event = cando_event,
+};
+
+static int __init cando_init(void)
+{
+ return hid_register_driver(&cando_driver);
+}
+
+static void __exit cando_exit(void)
+{
+ hid_unregister_driver(&cando_driver);
+}
+
+module_init(cando_init);
+module_exit(cando_exit);
+
projects / firefly-linux-kernel-4.4.55.git / commitdiff