Merge branch 'for-4.17/hid-elan' into for-linus

Pull new hid-elan driver, currently providing support for touchpad
found in certain HP Pavilion x2 laptops.

drivers/hid/Kconfig

@@ -274,6 +274,14 @@ config HID_EMS_FF
 	Currently the following devices are known to be supported:
 	 - Trio Linker Plus II
 
+config HID_ELAN
+	tristate "ELAN USB Touchpad Support"
+	depends on LEDS_CLASS && USB_HID
+	---help---
+	Say Y to enable support for the USB ELAN touchpad
+	Currently the following devices are known to be supported:
+	 - HP Pavilion X2 10-p0XX.
+
 config HID_ELECOM
 	tristate "ELECOM HID devices"
 	depends on HID

drivers/hid/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_HID_CP2112)	+= hid-cp2112.o
 obj-$(CONFIG_HID_CYPRESS)	+= hid-cypress.o
 obj-$(CONFIG_HID_DRAGONRISE)	+= hid-dr.o
 obj-$(CONFIG_HID_EMS_FF)	+= hid-emsff.o
+obj-$(CONFIG_HID_ELAN)		+= hid-elan.o
 obj-$(CONFIG_HID_ELECOM)	+= hid-elecom.o
 obj-$(CONFIG_HID_ELO)		+= hid-elo.o
 obj-$(CONFIG_HID_EZKEY)		+= hid-ezkey.o

drivers/hid/hid-elan.c

+/*
+ * HID Driver for ELAN Touchpad
+ *
+ * Currently only supports touchpad found on HP Pavilion X2 10
+ *
+ * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
+ *
+ * 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/hid.h>
+#include <linux/input/mt.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+
+#define ELAN_SINGLE_FINGER	0x81
+#define ELAN_MT_FIRST_FINGER	0x82
+#define ELAN_MT_SECOND_FINGER	0x83
+#define ELAN_INPUT_REPORT_SIZE	8
+
+#define ELAN_MUTE_LED_REPORT	0xBC
+#define ELAN_LED_REPORT_SIZE	8
+
+struct elan_touchpad_settings {
+	u8 max_fingers;
+	u16 max_x;
+	u16 max_y;
+	u8 max_area_x;
+	u8 max_area_y;
+	u8 max_w;
+	int usb_bInterfaceNumber;
+};
+
+struct elan_drvdata {
+	struct input_dev *input;
+	u8 prev_report[ELAN_INPUT_REPORT_SIZE];
+	struct led_classdev mute_led;
+	u8 mute_led_state;
+	struct elan_touchpad_settings *settings;
+};
+
+static int is_not_elan_touchpad(struct hid_device *hdev)
+{
+	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+
+	return (intf->altsetting->desc.bInterfaceNumber != drvdata->settings->usb_bInterfaceNumber);
+}
+
+static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+			      struct hid_field *field, struct hid_usage *usage,
+			      unsigned long **bit, int *max)
+{
+	if (is_not_elan_touchpad(hdev))
+		return 0;
+
+	if (field->report->id == ELAN_SINGLE_FINGER ||
+	    field->report->id == ELAN_MT_FIRST_FINGER ||
+	    field->report->id == ELAN_MT_SECOND_FINGER)
+		return -1;
+
+	return 0;
+}
+
+static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
+{
+	int ret;
+	struct input_dev *input;
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+
+	if (is_not_elan_touchpad(hdev))
+		return 0;
+
+	input = devm_input_allocate_device(&hdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "Elan Touchpad";
+	input->phys = hdev->phys;
+	input->uniq = hdev->uniq;
+	input->id.bustype = hdev->bus;
+	input->id.vendor  = hdev->vendor;
+	input->id.product = hdev->product;
+	input->id.version = hdev->version;
+	input->dev.parent = &hdev->dev;
+
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+			     drvdata->settings->max_x, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+			     drvdata->settings->max_y, 0, 0);
+	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
+			     drvdata->settings->max_fingers, 0, 0);
+	input_set_abs_params(input, ABS_TOOL_WIDTH, 0,
+			     drvdata->settings->max_w, 0, 0);
+
+	__set_bit(BTN_LEFT, input->keybit);
+	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+
+	ret = input_mt_init_slots(input, drvdata->settings->max_fingers,
+				  INPUT_MT_POINTER);
+	if (ret) {
+		hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
+		return ret;
+	}
+
+	ret = input_register_device(input);
+	if (ret) {
+		hid_err(hdev, "Failed to register elan input device: %d\n",
+			ret);
+		input_free_device(input);
+		return ret;
+	}
+
+	drvdata->input = input;
+
+	return 0;
+}
+
+static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
+				unsigned int slot_num)
+{
+	struct input_dev *input = drvdata->input;
+	int x, y, w;
+
+	bool active = !!data;
+
+	input_mt_slot(input, slot_num);
+	input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
+	if (active) {
+		x = ((data[0] & 0xF0) << 4) | data[1];
+		y = drvdata->settings->max_y -
+		    (((data[0] & 0x07) << 8) | data[2]);
+		w = data[4];
+
+		input_report_abs(input, ABS_MT_POSITION_X, x);
+		input_report_abs(input, ABS_MT_POSITION_Y, y);
+		input_report_abs(input, ABS_TOOL_WIDTH, w);
+	}
+}
+
+static void elan_report_input(struct elan_drvdata *drvdata, u8 *data)
+{
+	int i;
+	struct input_dev *input = drvdata->input;
+
+	/*
+	 * There is 3 types of reports: for single touch,
+	 * for multitouch - first finger and for multitouch - second finger
+	 *
+	 * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
+	 *
+	 * byte 1: 1   0   0   0   0   0   0   1  // 0x81 or 0x82
+	 * byte 2: 0   0   0   0   0   0   0   0  // looks like unused
+	 * byte 3: f5  f4  f3  f2  f1  0   0   L
+	 * byte 4: x12 x11 x10 x9  0?  y11 y10 y9
+	 * byte 5: x8  x7  x6  x5  x4  x3  x2  x1
+	 * byte 6: y8  y7  y6  y5  y4  y3  y2  y1
+	 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
+	 * byte 8: w8  w7  w6  w5  w4  w3  w2  w1
+	 *
+	 * packet structure for ELAN_MT_SECOND_FINGER:
+	 *
+	 * byte 1: 1   0   0   0   0   0   1   1  // 0x83
+	 * byte 2: x12 x11 x10 x9  0   y11 y10 y9
+	 * byte 3: x8  x7  x6  x5  x4  x3  x2  x1
+	 * byte 4: y8  y7  y6  y5  y4  y3  y2  y1
+	 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
+	 * byte 6: w8  w7  w6  w5  w4  w3  w2  w1
+	 * byte 7: 0   0   0   0   0   0   0   0
+	 * byte 8: 0   0   0   0   0   0   0   0
+	 *
+	 * f5-f1: finger touch bits
+	 * L: clickpad button
+	 * sy / sx: not sure yet, but this looks like rectangular
+	 * area for finger
+	 * w: looks like finger width
+	 */
+
+	if (data[0] == ELAN_SINGLE_FINGER) {
+		for (i = 0; i < drvdata->settings->max_fingers; i++) {
+			if (data[2] & BIT(i + 3))
+				elan_report_mt_slot(drvdata, data + 3, i);
+			else
+				elan_report_mt_slot(drvdata, NULL, i);
+		}
+		input_report_key(input, BTN_LEFT, data[2] & 0x01);
+	}
+	/*
+	 * When touched with two fingers Elan touchpad will emit two HID reports
+	 * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
+	 * we will save ELAN_MT_FIRST_FINGER report and wait for
+	 * ELAN_MT_SECOND_FINGER to finish multitouch
+	 */
+	if (data[0] == ELAN_MT_FIRST_FINGER) {
+		memcpy(drvdata->prev_report, data,
+		       sizeof(drvdata->prev_report));
+		return;
+	}
+
+	if (data[0] == ELAN_MT_SECOND_FINGER) {
+		int first = 0;
+		u8 *prev_report = drvdata->prev_report;
+
+		if (prev_report[0] != ELAN_MT_FIRST_FINGER)
+			return;
+
+		for (i = 0; i < drvdata->settings->max_fingers; i++) {
+			if (prev_report[2] & BIT(i + 3)) {
+				if (!first) {
+					first = 1;
+					elan_report_mt_slot(drvdata, prev_report + 3, i);
+				} else {
+					elan_report_mt_slot(drvdata, data + 1, i);
+				}
+			} else {
+				elan_report_mt_slot(drvdata, NULL, i);
+			}
+		}
+		input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
+	}
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+}
+
+static int elan_raw_event(struct hid_device *hdev,
+			  struct hid_report *report, u8 *data, int size)
+{
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+
+	if (is_not_elan_touchpad(hdev))
+		return 0;
+
+	if (data[0] == ELAN_SINGLE_FINGER ||
+	    data[0] == ELAN_MT_FIRST_FINGER ||
+	    data[0] == ELAN_MT_SECOND_FINGER) {
+		if (size == ELAN_INPUT_REPORT_SIZE) {
+			elan_report_input(drvdata, data);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static int elan_start_multitouch(struct hid_device *hdev)
+{
+	int ret;
+
+	/*
+	 * This byte sequence will enable multitouch mode and disable
+	 * mouse emulation
+	 */
+	const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
+	unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);
+
+	if (!dmabuf)
+		return -ENOMEM;
+
+	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
+				 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+
+	kfree(dmabuf);
+
+	if (ret != sizeof(buf)) {
+		hid_err(hdev, "Failed to start multitouch: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
+{
+	struct device *dev = led_cdev->dev->parent;
+	struct hid_device *hdev = to_hid_device(dev);
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+
+	return drvdata->mute_led_state;
+}
+
+static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
+				       enum led_brightness value)
+{
+	int ret;
+	u8 led_state;
+	struct device *dev = led_cdev->dev->parent;
+	struct hid_device *hdev = to_hid_device(dev);
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+
+	unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);
+
+	if (!dmabuf)
+		return -ENOMEM;
+
+	led_state = !!value;
+
+	dmabuf[0] = ELAN_MUTE_LED_REPORT;
+	dmabuf[1] = 0x02;
+	dmabuf[2] = led_state;
+
+	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
+				 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+
+	kfree(dmabuf);
+
+	if (ret != ELAN_LED_REPORT_SIZE) {
+		hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
+		return ret;
+	}
+
+	drvdata->mute_led_state = led_state;
+	return 0;
+}
+
+static int elan_init_mute_led(struct hid_device *hdev)
+{
+	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
+	struct led_classdev *mute_led = &drvdata->mute_led;
+
+	mute_led->name = "elan:red:mute";
+	mute_led->brightness_get = elan_mute_led_get_brigtness;
+	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
+	mute_led->max_brightness = LED_ON;
+	mute_led->dev = &hdev->dev;
+
+	return devm_led_classdev_register(&hdev->dev, mute_led);
+}
+
+static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+	struct elan_drvdata *drvdata;
+
+	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
+
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->settings = (struct elan_touchpad_settings *)id->driver_data;
+	hid_set_drvdata(hdev, drvdata);
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "Hid Parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "Hid hw start failed\n");
+		return ret;
+	}
+
+	if (is_not_elan_touchpad(hdev))
+		return 0;
+
+	if (!drvdata->input) {
+		hid_err(hdev, "Input device is not registred\n");
+		ret = -ENAVAIL;
+		goto err;
+	}
+
+	ret = elan_start_multitouch(hdev);
+	if (ret)
+		goto err;
+
+	ret = elan_init_mute_led(hdev);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void elan_remove(struct hid_device *hdev)
+{
+	hid_hw_stop(hdev);
+}
+
+static const struct elan_touchpad_settings hp_x2_10_touchpad_data = {
+	.max_fingers = 5,
+	.max_x = 2930,
+	.max_y = 1250,
+	.max_area_x = 15,
+	.max_area_y = 15,
+	.max_w = 255,
+	.usb_bInterfaceNumber = 1,
+};
+
+static const struct hid_device_id elan_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
+		(kernel_ulong_t)&hp_x2_10_touchpad_data},
+	{ }
+};
+
+MODULE_DEVICE_TABLE(hid, elan_devices);
+
+static struct hid_driver elan_driver = {
+	.name = "elan",
+	.id_table = elan_devices,
+	.input_mapping = elan_input_mapping,
+	.input_configured = elan_input_configured,
+	.raw_event = elan_raw_event,
+	.probe = elan_probe,
+	.remove = elan_remove,
+};
+
+module_hid_driver(elan_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexandrov Stanislav");
+MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");

drivers/hid/hid-ids.h

@@ -369,6 +369,7 @@
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001	0xa001
 
 #define USB_VENDOR_ID_ELAN		0x04f3
+#define USB_DEVICE_ID_HP_X2_10_COVER	0x0755
 
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061

drivers/hid/hid-quirks.c

@@ -335,6 +335,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0006) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0011) },
 #endif
+#if IS_ENABLED(CONFIG_HID_ELAN)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER) },
+#endif
 #if IS_ENABLED(CONFIG_HID_ELECOM)
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },