[RFC ebeam PATCH 0/3] new USB eBeam input driver

[RFC ebeam PATCH 0/3] new USB eBeam input driver

[Yann Cantin]

Hi,

New USB input driver for eBeam devices.

Currently supported (tested) :
- Luidia eBeam classic projection and edge projection models
- Nec "interactive solution" NP01Wi1 & NP01Wi2 accessories.

Patch 1 to blacklist the devices for hid generic-usb.

Patch 2 is the actual driver.

Notable stuff :
- use div64_s64 for portable 64/64-bits divisions.
- 13 sysfs custom files : 9 values for the transformation matrix,
  4 for xy ranges and a calibration trigger.
- need userspace gui tool for calibration (ebeam.tuxfamily.org)

Side notes :
- The module run fine since 3.3.6, both x86_32 and 64.
- Already reviewed in 2012 and 2013, but i have'nt pushed for inclusion.
- The only recent change is switching to non world-writable sysfs files.
- There is a proprietary application suite based on libusb, hope it won't
  break with this driver.

Thanks for your help.

[RFC ebeam PATCH 1/2] hid: Blacklist eBeam devices

[Yann Cantin]

Signed-off-by: Yann Cantin <yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org>
---
 drivers/hid/hid-core.c | 6 ++++++
 drivers/hid/hid-ids.h  | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 157c627..db4c7ee 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2267,6 +2267,12 @@ static const struct hid_device_id hid_ignore_list[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DELORME, USB_DEVICE_ID_DELORME_EM_LT20) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, 0x0004) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, 0x000a) },
+#if defined(CONFIG_INPUT_EBEAM_USB)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB1) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB1) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB2) },
+#endif
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ESSENTIAL_REALITY, USB_DEVICE_ID_ESSENTIAL_REALITY_P5) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ETT, USB_DEVICE_ID_TC5UH) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ETT, USB_DEVICE_ID_TC4UM) },
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index b04b082..ca013c2 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -303,6 +303,12 @@
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_73F7	0x73f7
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001	0xa001
 
+#define USB_VENDOR_ID_EFI		0x2650
+#define USB_DEVICE_ID_EFI_EBEAM_USB1	0x1311
+#define USB_DEVICE_ID_EFI_EBEAM_USB2	0x1315
+#define USB_DEVICE_ID_EFI_EBEAM_BT_USB1	0x1313
+#define USB_DEVICE_ID_EFI_EBEAM_BT_USB2	0x1320
+
 #define USB_VENDOR_ID_ELAN		0x04f3
 #define USB_DEVICE_ID_ELAN_TOUCHSCREEN	0x0089
 #define USB_DEVICE_ID_ELAN_TOUCHSCREEN_009B	0x009b
-- 
2.3.8

[RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Yann Cantin]

Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
---
 Documentation/ABI/testing/sysfs-driver-ebeam |  53 ++
 drivers/input/misc/Kconfig                   |  22 +
 drivers/input/misc/Makefile                  |   1 +
 drivers/input/misc/ebeam.c                   | 777 +++++++++++++++++++++++++++
 4 files changed, 853 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-ebeam
 create mode 100644 drivers/input/misc/ebeam.c

diff --git a/Documentation/ABI/testing/sysfs-driver-ebeam b/Documentation/ABI/testing/sysfs-driver-ebeam
new file mode 100644
index 0000000..6873db5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-ebeam
@@ -0,0 +1,53 @@
+What:		/sys/class/input/inputXX/device/min_x
+		/sys/class/input/inputXX/device/min_y
+		/sys/class/input/inputXX/device/max_x
+		/sys/class/input/inputXX/device/max_y
+Date:		Jul 2015
+Kernel Version:	4.1
+Contact:	yann.cantin@laposte.net
+		linux-usb@vger.kernel.org
+Description:
+		Reading from these files return the actually used range values of
+		the reported coordinates.
+		Writing to these files preset these range values.
+		See below for the calibration procedure.
+
+What:		/sys/class/input/inputXX/device/h[1..9]
+Date:		Jul 2015
+Kernel Version:	4.1
+Contact:	yann.cantin@laposte.net
+		linux-usb@vger.kernel.org
+Description:
+		Reading from these files return the 3x3 transformation matrix elements
+		actually used, in row-major.
+		Writing to these files preset these elements values.
+		See below for the calibration procedure.
+
+What:		/sys/class/input/inputXX/device/calibrated
+Date:		Jul 2015
+Kernel Version:	4.1
+Contact:	yann.cantin@laposte.net
+		linux-usb@vger.kernel.org
+Description:
+		Reading from this file :
+		- Return 0 if the driver is in "un-calibrated" mode : it actually send
+		  raw coordinates in the device's internal coordinates system.
+		- Return 1 if the driver is in "calibrated" mode : it send computed coordinates
+		  that (hopefully) matches the screen's coordinates system.
+		Writing 1 to this file enable the "calibrated" mode, 0 reset the driver in
+		"un-calibrated" mode.
+
+Calibration procedure :
+
+When loaded, the driver is in "un-calibrated" mode : it send device's raw coordinates
+in the [0..65535]x[0..65535] range, the transformation matrix is the identity.
+
+A calibration program have to compute a homography transformation matrix that convert
+the device's raw coordinates to the matching screen's ones.
+It then write to the appropriate sysfs files the computed values, pre-setting the
+driver's parameters : xy range, and the matrix's elements.
+When all values are passed, it write 1 to the calibrated sysfs file to enable the "calibrated" mode.
+
+Warning : The parameters aren't used until 1 is writen to the calibrated sysfs file.
+
+Writing 0 to the calibrated sysfs file reset the driver in "un-calibrated" mode.
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index d4f0a81..22c46a4 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -103,6 +103,28 @@ config INPUT_E3X0_BUTTON
 	  To compile this driver as a module, choose M here: the
 	  module will be called e3x0_button.
 
+config INPUT_EBEAM_USB
+	tristate "USB eBeam driver"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you have a USB eBeam pointing device and want to
+	  use it without any proprietary user space tools.
+
+	  Have a look at <http://ebeam.tuxfamily.org/> for
+	  a usage description and the required user-space tools.
+
+	  Supported devices :
+	    - Luidia eBeam Classic Projection and eBeam Edge Projection
+	    - Nec NP01Wi1 & NP01Wi2 interactive solution
+
+	  Supposed working devices, need test, may lack functionality :
+	    - Luidia eBeam Edge Whiteboard and eBeam Engage
+	    - Hitachi Starboard FX-63, FX-77, FX-82, FX-77GII
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ebeam.
+
 config INPUT_PCSPKR
 	tristate "PC Speaker support"
 	depends on PCSPKR_PLATFORM
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 53df07d..125f8a9 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
 obj-$(CONFIG_INPUT_DA9063_ONKEY)	+= da9063_onkey.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
 obj-$(CONFIG_INPUT_E3X0_BUTTON)		+= e3x0-button.o
+obj-$(CONFIG_INPUT_EBEAM_USB)		+= ebeam.o
 obj-$(CONFIG_INPUT_DRV260X_HAPTICS)	+= drv260x.o
 obj-$(CONFIG_INPUT_DRV2665_HAPTICS)	+= drv2665.o
 obj-$(CONFIG_INPUT_DRV2667_HAPTICS)	+= drv2667.o
diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
new file mode 100644
index 0000000..79cac51
--- /dev/null
+++ b/drivers/input/misc/ebeam.c
@@ -0,0 +1,777 @@
+/******************************************************************************
+ *
+ * eBeam driver
+ *
+ * Copyright (C) 2012-2015 Yann Cantin (yann.cantin@laposte.net)
+ *
+ *	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.
+ *
+ *  based on
+ *
+ *	usbtouchscreen.c by Daniel Ritz <daniel.ritz@gmx.ch>
+ *	aiptek.c (sysfs/settings) by Chris Atenasio <chris@crud.net>
+ *				     Bryan W. Headley <bwheadley@earthlink.net>
+ *
+ *****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/math64.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+#include <asm/unaligned.h>
+
+#define DRIVER_AUTHOR	"Yann Cantin <yann.cantin@laposte.net>"
+#define DRIVER_DESC	"USB eBeam Driver"
+
+/* Common values for eBeam devices */
+#define REPT_SIZE	8	/* packet size            */
+#define MIN_RAW_X	0	/* raw coordinates ranges */
+#define MAX_RAW_X	0xFFFF
+#define MIN_RAW_Y	0
+#define MAX_RAW_Y	0xFFFF
+
+/* Electronics For Imaging, Inc */
+#define USB_VENDOR_ID_EFI	0x2650
+
+/* eBeam hardware :			*/
+/*	Luidia Classic and Edge		*/
+/*	Nec NP01Wi1 & NP01Wi2		*/
+#define USB_DEVICE_ID_EFI_EBEAM_USB1	0x1311
+/*	From https://github.com/dpiquet	*/
+/*	Need confirmation		*/
+#define USB_DEVICE_ID_EFI_EBEAM_USB2	0x1315
+#define USB_DEVICE_ID_EFI_EBEAM_BT_USB1	0x1313
+#define USB_DEVICE_ID_EFI_EBEAM_BT_USB2	0x1320
+
+#define EBEAM_BTN_TIP	0x1	/* tip    */
+#define EBEAM_BTN_LIT	0x2	/* little */
+#define EBEAM_BTN_BIG	0x4	/* big    */
+
+/* ebeam settings */
+struct ebeam_settings {
+	int min_x;	/* computed coordinates ranges for the input layer */
+	int max_x;
+	int min_y;
+	int max_y;
+
+	/* H matrix */
+	s64 h1;
+	s64 h2;
+	s64 h3;
+	s64 h4;
+	s64 h5;
+	s64 h6;
+	s64 h7;
+	s64 h8;
+	s64 h9;
+};
+
+/* ebeam device */
+struct ebeam_device {
+	unsigned char		*data;
+	dma_addr_t		data_dma;
+	unsigned char		*buffer;
+	int			buf_len;
+	struct urb		*irq;
+	struct usb_interface	*interface;
+	struct input_dev	*input;
+	char			name[128];
+	char			phys[64];
+	void			*priv;
+
+	struct ebeam_settings	cursetting;	/* device's current settings */
+	struct ebeam_settings	newsetting;	/* ... and new ones          */
+
+	bool			calibrated;	/* false : send raw          */
+						/* true  : send computed     */
+
+	u16			raw_x;		/* raw coordinates           */
+	u16			raw_y;
+	int			x;		/* computed coordinates      */
+	int			y;
+	int			btn_map;	/* internal buttons map      */
+};
+
+/* device types */
+enum {
+	DEVTYPE_EBEAM,
+};
+
+static const struct usb_device_id ebeam_devices[] = {
+	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB1),
+	 .driver_info = DEVTYPE_EBEAM},
+	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB2),
+	 .driver_info = DEVTYPE_EBEAM},
+	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB1),
+	 .driver_info = DEVTYPE_EBEAM},
+	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB2),
+	 .driver_info = DEVTYPE_EBEAM},
+	{}
+};
+
+static void ebeam_init_settings(struct ebeam_device *ebeam)
+{
+	ebeam->calibrated = false;
+
+	/* Init (x,y) min/max to raw ones */
+	ebeam->cursetting.min_x = ebeam->newsetting.min_x = MIN_RAW_X;
+	ebeam->cursetting.max_x = ebeam->newsetting.max_x = MAX_RAW_X;
+	ebeam->cursetting.min_y = ebeam->newsetting.min_y = MIN_RAW_Y;
+	ebeam->cursetting.max_y = ebeam->newsetting.max_y = MAX_RAW_Y;
+
+	/* Safe values for the H matrix (Identity) */
+	ebeam->cursetting.h1 = ebeam->newsetting.h1 = 1;
+	ebeam->cursetting.h2 = ebeam->newsetting.h2 = 0;
+	ebeam->cursetting.h3 = ebeam->newsetting.h3 = 0;
+
+	ebeam->cursetting.h4 = ebeam->newsetting.h4 = 0;
+	ebeam->cursetting.h5 = ebeam->newsetting.h5 = 1;
+	ebeam->cursetting.h6 = ebeam->newsetting.h6 = 0;
+
+	ebeam->cursetting.h7 = ebeam->newsetting.h7 = 0;
+	ebeam->cursetting.h8 = ebeam->newsetting.h8 = 0;
+	ebeam->cursetting.h9 = ebeam->newsetting.h9 = 1;
+}
+
+static void ebeam_setup_input(struct ebeam_device *ebeam,
+			      struct input_dev *input_dev)
+{
+	unsigned long flags;
+
+	/* Take event lock while modifying parameters */
+	spin_lock_irqsave(&input_dev->event_lock, flags);
+
+	/* Properties */
+	set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
+
+	/* Events generated */
+	set_bit(EV_KEY, input_dev->evbit);
+	set_bit(EV_ABS, input_dev->evbit);
+
+	/* Keys */
+	set_bit(BTN_LEFT,	input_dev->keybit);
+	set_bit(BTN_MIDDLE,	input_dev->keybit);
+	set_bit(BTN_RIGHT,	input_dev->keybit);
+
+	/* Axis */
+	if (!ebeam->calibrated) {
+		ebeam->cursetting.min_x = MIN_RAW_X;
+		ebeam->cursetting.max_x = MAX_RAW_X;
+		ebeam->cursetting.min_y = MIN_RAW_Y;
+		ebeam->cursetting.max_y = MAX_RAW_Y;
+	}
+
+	input_set_abs_params(input_dev, ABS_X,
+			     ebeam->cursetting.min_x, ebeam->cursetting.max_x,
+			     0, 0);
+	input_set_abs_params(input_dev, ABS_Y,
+			     ebeam->cursetting.min_y, ebeam->cursetting.max_y,
+			     0, 0);
+
+	spin_unlock_irqrestore(&input_dev->event_lock, flags);
+}
+
+/*******************************************************************************
+ * sysfs part
+ */
+
+/*
+ * screen min/max and H matrix coefs
+ * _get return *current* value
+ * _set set new value
+ */
+#define DEVICE_MINMAX_ATTR(MM)						       \
+static ssize_t ebeam_##MM##_get(struct device *dev,			       \
+				struct device_attribute *attr,		       \
+				char *buf)				       \
+{									       \
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
+									       \
+	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->cursetting.MM);	       \
+}									       \
+static ssize_t ebeam_##MM##_set(struct device *dev,			       \
+				struct device_attribute *attr,		       \
+				const char *buf,			       \
+				size_t count)				       \
+{									       \
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
+	int err, MM;							       \
+									       \
+	err = kstrtoint(buf, 10, &MM);					       \
+	if (err)							       \
+		return err;						       \
+									       \
+	ebeam->newsetting.MM = MM;					       \
+	return count;							       \
+}									       \
+static DEVICE_ATTR(MM, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,		       \
+		   ebeam_##MM##_get,					       \
+		   ebeam_##MM##_set)
+
+DEVICE_MINMAX_ATTR(min_x);
+DEVICE_MINMAX_ATTR(max_x);
+DEVICE_MINMAX_ATTR(min_y);
+DEVICE_MINMAX_ATTR(max_y);
+
+#define DEVICE_H_ATTR(SET_ID)						       \
+static ssize_t ebeam_h##SET_ID##_get(struct device *dev,		       \
+				     struct device_attribute *attr,	       \
+				     char *buf)				       \
+{									       \
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
+									       \
+	return snprintf(buf, PAGE_SIZE, "%lld\n", ebeam->cursetting.h##SET_ID);\
+}									       \
+static ssize_t ebeam_h##SET_ID##_set(struct device *dev,		       \
+				     struct device_attribute *attr,	       \
+				     const char *buf,			       \
+				     size_t count)			       \
+{									       \
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
+	int err;							       \
+	u64 h;								       \
+									       \
+	err = kstrtoll(buf, 10, &h);					       \
+	if (err)							       \
+		return err;						       \
+									       \
+	ebeam->newsetting.h##SET_ID = h;				       \
+	return count;							       \
+}									       \
+static DEVICE_ATTR(h##SET_ID, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,	       \
+		   ebeam_h##SET_ID##_get,				       \
+		   ebeam_h##SET_ID##_set)
+
+DEVICE_H_ATTR(1);
+DEVICE_H_ATTR(2);
+DEVICE_H_ATTR(3);
+DEVICE_H_ATTR(4);
+DEVICE_H_ATTR(5);
+DEVICE_H_ATTR(6);
+DEVICE_H_ATTR(7);
+DEVICE_H_ATTR(8);
+DEVICE_H_ATTR(9);
+
+/*
+ * sysfs calibrated
+ * Once H matrix coefs are set, writing 1 to this file triggers
+ * coordinates mapping.
+ * Anything else reset the device to un-calibrated mode,
+ * storing cursetting in newsetting.
+*/
+static ssize_t ebeam_calibrated_get(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->calibrated);
+}
+
+static ssize_t ebeam_calibrated_set(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf,
+				    size_t count)
+{
+	struct ebeam_device *ebeam = dev_get_drvdata(dev);
+	int err, c;
+
+	err = kstrtoint(buf, 10, &c);
+	if (err)
+		return err;
+
+	if (c == 1) {
+		memcpy(&ebeam->cursetting, &ebeam->newsetting,
+		       sizeof(struct ebeam_settings));
+		ebeam->calibrated = true;
+		ebeam_setup_input(ebeam, ebeam->input);
+	} else {
+		memcpy(&ebeam->newsetting, &ebeam->cursetting,
+		       sizeof(struct ebeam_settings));
+		ebeam->calibrated = false;
+		ebeam_setup_input(ebeam, ebeam->input);
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR(calibrated, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,
+		   ebeam_calibrated_get, ebeam_calibrated_set);
+
+static struct attribute *ebeam_attrs[] = {
+	&dev_attr_min_x.attr,
+	&dev_attr_min_y.attr,
+	&dev_attr_max_x.attr,
+	&dev_attr_max_y.attr,
+	&dev_attr_h1.attr,
+	&dev_attr_h2.attr,
+	&dev_attr_h3.attr,
+	&dev_attr_h4.attr,
+	&dev_attr_h5.attr,
+	&dev_attr_h6.attr,
+	&dev_attr_h7.attr,
+	&dev_attr_h8.attr,
+	&dev_attr_h9.attr,
+	&dev_attr_calibrated.attr,
+	NULL
+};
+
+static const struct attribute_group ebeam_attr_group = {
+	.attrs = ebeam_attrs,
+};
+
+/* IRQ */
+static int ebeam_read_data(struct ebeam_device *ebeam, unsigned char *pkt)
+{
+
+/*
+ * Packet description : 8 bytes
+ *
+ *  nop packet : FF FF FF FF FF FF FF FF
+ *
+ *  pkt[0] : Sensors
+ *	bit 1 : ultrasound signal (guessed)
+ *	bit 2 : IR signal (tested with a remote...) ;
+ *	readings OK : 0x03 (anything else is a show-stopper)
+ *
+ *  pkt[1] : raw_x low
+ *  pkt[2] : raw_x high
+ *
+ *  pkt[3] : raw_y low
+ *  pkt[4] : raw_y high
+ *
+ *  pkt[5] : fiability ?
+ *	often 0xC0
+ *	> 0x80 : OK
+ *
+ *  pkt[6] :
+ *	buttons state (low 4 bits)
+ *		0x1 = no buttons
+ *		bit 0 : tip (WARNING inversed : 0=pressed)
+ *		bit 1 : ? (always 0 during tests)
+ *		bit 2 : little (1=pressed)
+ *		bit 3 : big (1=pressed)
+ *
+ *	pointer ID : (high 4 bits)
+ *		Tested  : 0x6=wand ;
+ *		Guessed : 0x1=red ; 0x2=blue ; 0x3=green ; 0x4=black ;
+ *			  0x5=eraser
+ *		bit 4 : pointer ID
+ *		bit 5 : pointer ID
+ *		bit 6 : pointer ID
+ *		bit 7 : pointer ID
+ *
+ *
+ *  pkt[7] : fiability ?
+ *	often 0xFF
+ *
+ */
+
+	/* Filtering bad/nop packet */
+	if (pkt[0] != 0x03)
+		return 0;
+
+	ebeam->raw_x = get_unaligned_le16(&pkt[1]);
+	ebeam->raw_y = get_unaligned_le16(&pkt[3]);
+
+	ebeam->btn_map = (!(pkt[6] & 0x1)) |
+			 ((pkt[6] & 0x4) >> 1) |
+			 ((pkt[6] & 0x8) >> 1);
+
+	return 1;
+}
+
+/*
+ * IRQ
+ * compute screen coordinates from raw
+ * Overflow and negative values are ignored
+ */
+static bool ebeam_calculate_xy(struct ebeam_device *ebeam)
+{
+	/* 64-bits divisions handled by div64_s64 */
+
+	s64 scale;
+
+	if (!ebeam->calibrated) {
+		ebeam->x = ebeam->raw_x;
+		ebeam->y = ebeam->raw_y;
+	} else {
+		scale = ebeam->cursetting.h7 * ebeam->raw_x +
+			ebeam->cursetting.h8 * ebeam->raw_y +
+			ebeam->cursetting.h9;
+
+		/* Who want a division by zero in kernel ? */
+		if (scale == 0) {
+			dev_err(&(ebeam->interface)->dev,
+				"%s - Division by zero, wrong calibration.\n",
+				__func__);
+			dev_err(&(ebeam->interface)->dev,
+				"%s - Resetting to un-calibrated mode.\n",
+				__func__);
+			ebeam->calibrated = false;
+			return 0;
+		}
+
+		/*
+		 * We *must* round the result, but can't do (int) (v1/v2 + 0.5)
+		 *
+		 * (int) (v1/v2 + 0.5) <=> (int) ( (2*v1 + v2)/(2*v2) )
+		 */
+		ebeam->x =
+		    (int)div64_s64((((ebeam->cursetting.h1 * ebeam->raw_x +
+				      ebeam->cursetting.h2 * ebeam->raw_y +
+				      ebeam->cursetting.h3) << 1) + scale),
+				   (scale << 1));
+		ebeam->y =
+		    (int)div64_s64((((ebeam->cursetting.h4 * ebeam->raw_x +
+				      ebeam->cursetting.h5 * ebeam->raw_y +
+				      ebeam->cursetting.h6) << 1) + scale),
+				   (scale << 1));
+
+		/* check range */
+		if ((ebeam->x < ebeam->cursetting.min_x) ||
+		    (ebeam->x > ebeam->cursetting.max_x) ||
+		    (ebeam->y < ebeam->cursetting.min_y) ||
+		    (ebeam->y > ebeam->cursetting.max_y))
+			return 0;
+	}
+
+	return 1;
+}
+
+/* IRQ */
+static void ebeam_report_input(struct ebeam_device *ebeam)
+{
+	input_report_key(ebeam->input, BTN_LEFT,
+			 (ebeam->btn_map & EBEAM_BTN_TIP));
+	input_report_key(ebeam->input, BTN_MIDDLE,
+			 (ebeam->btn_map & EBEAM_BTN_LIT));
+	input_report_key(ebeam->input, BTN_RIGHT,
+			 (ebeam->btn_map & EBEAM_BTN_BIG));
+
+	input_report_abs(ebeam->input, ABS_X, ebeam->x);
+	input_report_abs(ebeam->input, ABS_Y, ebeam->y);
+
+	input_sync(ebeam->input);
+}
+
+/* IRQ */
+static void ebeam_process_pkt(struct ebeam_device *ebeam,
+			      unsigned char *pkt, int len)
+{
+	if (!ebeam_read_data(ebeam, pkt))
+		return;
+
+	if (!ebeam_calculate_xy(ebeam))
+		return;
+
+	ebeam_report_input(ebeam);
+}
+
+/* IRQ
+ * handler */
+static void ebeam_irq(struct urb *urb)
+{
+	struct ebeam_device *ebeam = urb->context;
+	struct device *dev = &ebeam->interface->dev;
+	int retval;
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ETIME:
+		/* this urb is timing out */
+		dev_dbg(dev,
+			"%s - urb timed out - was the device unplugged?\n",
+			__func__);
+		return;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+	case -EPIPE:
+		/* this urb is terminated, clean up */
+		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
+			__func__, urb->status);
+		return;
+	default:
+		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
+			__func__, urb->status);
+		goto exit;
+	}
+
+	ebeam_process_pkt(ebeam, ebeam->data, urb->actual_length);
+
+exit:
+	usb_mark_last_busy(interface_to_usbdev(ebeam->interface));
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval)
+		dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
+			__func__, retval);
+}
+
+static int ebeam_open(struct input_dev *input)
+{
+	struct ebeam_device *ebeam = input_get_drvdata(input);
+	int r;
+
+	ebeam->irq->dev = interface_to_usbdev(ebeam->interface);
+
+	r = usb_autopm_get_interface(ebeam->interface) ? -EIO : 0;
+	if (r < 0)
+		goto out;
+
+	if (usb_submit_urb(ebeam->irq, GFP_KERNEL)) {
+		r = -EIO;
+		goto out_put;
+	}
+
+	ebeam->interface->needs_remote_wakeup = 1;
+out_put:
+	usb_autopm_put_interface(ebeam->interface);
+out:
+	return r;
+}
+
+static void ebeam_close(struct input_dev *input)
+{
+	struct ebeam_device *ebeam = input_get_drvdata(input);
+	int r;
+
+	r = usb_autopm_get_interface(ebeam->interface);
+
+	usb_kill_urb(ebeam->irq);
+	ebeam->interface->needs_remote_wakeup = 0;
+
+	if (!r)
+		usb_autopm_put_interface(ebeam->interface);
+}
+
+static int ebeam_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct ebeam_device *ebeam = usb_get_intfdata(intf);
+
+	usb_kill_urb(ebeam->irq);
+
+	return 0;
+}
+
+static int ebeam_resume(struct usb_interface *intf)
+{
+	struct ebeam_device *ebeam = usb_get_intfdata(intf);
+	struct input_dev *input = ebeam->input;
+	int result = 0;
+
+	mutex_lock(&input->mutex);
+	if (input->users)
+		result = usb_submit_urb(ebeam->irq, GFP_NOIO);
+	mutex_unlock(&input->mutex);
+
+	return result;
+}
+
+static void ebeam_free_buffers(struct usb_device *udev,
+			       struct ebeam_device *ebeam)
+{
+	usb_free_coherent(udev, REPT_SIZE, ebeam->data, ebeam->data_dma);
+	kfree(ebeam->buffer);
+}
+
+static struct usb_endpoint_descriptor
+*ebeam_get_input_endpoint(struct usb_host_interface *interface)
+{
+	int i;
+
+	for (i = 0; i < interface->desc.bNumEndpoints; i++)
+		if (usb_endpoint_dir_in(&interface->endpoint[i].desc))
+			return &interface->endpoint[i].desc;
+
+	return NULL;
+}
+
+static int ebeam_probe(struct usb_interface *intf,
+		       const struct usb_device_id *id)
+{
+	struct ebeam_device *ebeam;
+	struct input_dev *input_dev;
+	struct usb_endpoint_descriptor *endpoint;
+	struct usb_device *udev = interface_to_usbdev(intf);
+	int err = -ENOMEM;
+
+	endpoint = ebeam_get_input_endpoint(intf->cur_altsetting);
+	if (!endpoint)
+		return -ENXIO;
+
+	ebeam = kzalloc(sizeof(struct ebeam_device), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ebeam || !input_dev)
+		goto out_free;
+
+	ebeam_init_settings(ebeam);
+
+	ebeam->data = usb_alloc_coherent(udev, REPT_SIZE,
+					 GFP_KERNEL, &ebeam->data_dma);
+	if (!ebeam->data)
+		goto out_free;
+
+	ebeam->irq = usb_alloc_urb(0, GFP_KERNEL);
+	if (!ebeam->irq) {
+		dev_dbg(&intf->dev,
+			"%s - usb_alloc_urb failed: ebeam->irq\n", __func__);
+		goto out_free_buffers;
+	}
+
+	ebeam->interface = intf;
+	ebeam->input = input_dev;
+
+	/* setup name */
+	snprintf(ebeam->name, sizeof(ebeam->name),
+		 "USB eBeam %04x:%04x",
+		 le16_to_cpu(udev->descriptor.idVendor),
+		 le16_to_cpu(udev->descriptor.idProduct));
+
+	if (udev->manufacturer || udev->product) {
+		strlcat(ebeam->name, " (", sizeof(ebeam->name));
+
+		if (udev->manufacturer)
+			strlcat(ebeam->name,
+				udev->manufacturer,
+				sizeof(ebeam->name));
+
+		if (udev->product) {
+			if (udev->manufacturer)
+				strlcat(ebeam->name, " ", sizeof(ebeam->name));
+			strlcat(ebeam->name,
+				udev->product,
+				sizeof(ebeam->name));
+		}
+
+		if (strlcat(ebeam->name, ")", sizeof(ebeam->name))
+		    >= sizeof(ebeam->name)) {
+			/* overflowed, closing ) anyway */
+			ebeam->name[sizeof(ebeam->name) - 2] = ')';
+		}
+	}
+
+	/* usb tree */
+	usb_make_path(udev, ebeam->phys, sizeof(ebeam->phys));
+	strlcat(ebeam->phys, "/input0", sizeof(ebeam->phys));
+
+	/* input setup */
+	input_dev->name = ebeam->name;
+	input_dev->phys = ebeam->phys;
+	usb_to_input_id(udev, &input_dev->id);
+	input_dev->dev.parent = &intf->dev;
+
+	input_set_drvdata(input_dev, ebeam);
+
+	input_dev->open = ebeam_open;
+	input_dev->close = ebeam_close;
+
+	/* usb urb setup */
+	if (usb_endpoint_type(endpoint) == USB_ENDPOINT_XFER_INT)
+		usb_fill_int_urb(ebeam->irq,
+				 udev,
+				 usb_rcvintpipe(udev,
+						endpoint->bEndpointAddress),
+				 ebeam->data,
+				 REPT_SIZE,
+				 ebeam_irq,
+				 ebeam,
+				 endpoint->bInterval);
+	else
+		usb_fill_bulk_urb(ebeam->irq,
+				  udev,
+				  usb_rcvbulkpipe(udev,
+						  endpoint->bEndpointAddress),
+				  ebeam->data,
+				  REPT_SIZE,
+				  ebeam_irq,
+				  ebeam);
+
+	ebeam->irq->dev = udev;
+	ebeam->irq->transfer_dma = ebeam->data_dma;
+	ebeam->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	/* usb final setup */
+	usb_set_intfdata(intf, ebeam);
+
+	/* sysfs setup */
+	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
+	if (err) {
+		dev_dbg(&intf->dev,
+			"%s - cannot create sysfs group, err: %d\n",
+			__func__, err);
+		goto out_free_usb;
+	}
+
+	/* input final setup */
+	ebeam_setup_input(ebeam, input_dev);
+
+	err = input_register_device(ebeam->input);
+	if (err) {
+		dev_dbg(&intf->dev,
+			"%s - input_register_device failed, err: %d\n",
+			__func__, err);
+		goto out_remove_sysfs;
+	}
+
+	return 0;
+
+out_remove_sysfs:
+	sysfs_remove_group(&intf->dev.kobj, &ebeam_attr_group);
+out_free_usb:
+	usb_set_intfdata(intf, NULL);
+	usb_free_urb(ebeam->irq);
+out_free_buffers:
+	ebeam_free_buffers(udev, ebeam);
+out_free:
+	input_free_device(input_dev);
+	kfree(ebeam);
+	return err;
+}
+
+static void ebeam_disconnect(struct usb_interface *intf)
+{
+	struct ebeam_device *ebeam = usb_get_intfdata(intf);
+
+	if (!ebeam)
+		return;
+
+	dev_dbg(&intf->dev,
+		"%s - ebeam is initialized, cleaning up\n", __func__);
+
+	usb_set_intfdata(intf, NULL);
+	/* this will stop IO via close */
+	input_unregister_device(ebeam->input);
+	sysfs_remove_group(&intf->dev.kobj, &ebeam_attr_group);
+	usb_free_urb(ebeam->irq);
+	ebeam_free_buffers(interface_to_usbdev(intf), ebeam);
+	kfree(ebeam);
+}
+
+MODULE_DEVICE_TABLE(usb, ebeam_devices);
+
+static struct usb_driver ebeam_driver = {
+	.name =			"ebeam",
+	.probe =		ebeam_probe,
+	.disconnect =		ebeam_disconnect,
+	.suspend =		ebeam_suspend,
+	.resume =		ebeam_resume,
+	.reset_resume =		ebeam_resume,
+	.id_table =		ebeam_devices,
+	.supports_autosuspend =	1,
+};
+
+module_usb_driver(ebeam_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
-- 
2.3.8

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Greg KH]

On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
> Signed-off-by: Yann Cantin <yann.cantin@laposte.net>

You need some kind of text in the changelog here...

> ---
>  Documentation/ABI/testing/sysfs-driver-ebeam |  53 ++
>  drivers/input/misc/Kconfig                   |  22 +
>  drivers/input/misc/Makefile                  |   1 +
>  drivers/input/misc/ebeam.c                   | 777 +++++++++++++++++++++++++++
>  4 files changed, 853 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-driver-ebeam
>  create mode 100644 drivers/input/misc/ebeam.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ebeam b/Documentation/ABI/testing/sysfs-driver-ebeam
> new file mode 100644
> index 0000000..6873db5
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-driver-ebeam
> @@ -0,0 +1,53 @@
> +What:		/sys/class/input/inputXX/device/min_x
> +		/sys/class/input/inputXX/device/min_y
> +		/sys/class/input/inputXX/device/max_x
> +		/sys/class/input/inputXX/device/max_y
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin@laposte.net
> +		linux-usb@vger.kernel.org
> +Description:
> +		Reading from these files return the actually used range values of
> +		the reported coordinates.
> +		Writing to these files preset these range values.
> +		See below for the calibration procedure.
> +
> +What:		/sys/class/input/inputXX/device/h[1..9]
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin@laposte.net
> +		linux-usb@vger.kernel.org
> +Description:
> +		Reading from these files return the 3x3 transformation matrix elements
> +		actually used, in row-major.
> +		Writing to these files preset these elements values.
> +		See below for the calibration procedure.
> +
> +What:		/sys/class/input/inputXX/device/calibrated
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin@laposte.net
> +		linux-usb@vger.kernel.org
> +Description:
> +		Reading from this file :
> +		- Return 0 if the driver is in "un-calibrated" mode : it actually send
> +		  raw coordinates in the device's internal coordinates system.
> +		- Return 1 if the driver is in "calibrated" mode : it send computed coordinates
> +		  that (hopefully) matches the screen's coordinates system.
> +		Writing 1 to this file enable the "calibrated" mode, 0 reset the driver in
> +		"un-calibrated" mode.
> +
> +Calibration procedure :
> +
> +When loaded, the driver is in "un-calibrated" mode : it send device's raw coordinates
> +in the [0..65535]x[0..65535] range, the transformation matrix is the identity.
> +
> +A calibration program have to compute a homography transformation matrix that convert
> +the device's raw coordinates to the matching screen's ones.
> +It then write to the appropriate sysfs files the computed values, pre-setting the
> +driver's parameters : xy range, and the matrix's elements.
> +When all values are passed, it write 1 to the calibrated sysfs file to enable the "calibrated" mode.
> +
> +Warning : The parameters aren't used until 1 is writen to the calibrated sysfs file.
> +
> +Writing 0 to the calibrated sysfs file reset the driver in "un-calibrated" mode.


What tool(s) use these sysfs files?  Don't we already have "normal"
events for these types of things such that we don't have to make up new
sysfs files for these?

> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index d4f0a81..22c46a4 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -103,6 +103,28 @@ config INPUT_E3X0_BUTTON
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called e3x0_button.
>  
> +config INPUT_EBEAM_USB
> +	tristate "USB eBeam driver"
> +	depends on USB_ARCH_HAS_HCD
> +	select USB
> +	help
> +	  Say Y here if you have a USB eBeam pointing device and want to
> +	  use it without any proprietary user space tools.
> +
> +	  Have a look at <http://ebeam.tuxfamily.org/> for
> +	  a usage description and the required user-space tools.
> +
> +	  Supported devices :
> +	    - Luidia eBeam Classic Projection and eBeam Edge Projection
> +	    - Nec NP01Wi1 & NP01Wi2 interactive solution
> +
> +	  Supposed working devices, need test, may lack functionality :
> +	    - Luidia eBeam Edge Whiteboard and eBeam Engage
> +	    - Hitachi Starboard FX-63, FX-77, FX-82, FX-77GII
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ebeam.
> +
>  config INPUT_PCSPKR
>  	tristate "PC Speaker support"
>  	depends on PCSPKR_PLATFORM
> diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
> index 53df07d..125f8a9 100644
> --- a/drivers/input/misc/Makefile
> +++ b/drivers/input/misc/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
>  obj-$(CONFIG_INPUT_DA9063_ONKEY)	+= da9063_onkey.o
>  obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
>  obj-$(CONFIG_INPUT_E3X0_BUTTON)		+= e3x0-button.o
> +obj-$(CONFIG_INPUT_EBEAM_USB)		+= ebeam.o
>  obj-$(CONFIG_INPUT_DRV260X_HAPTICS)	+= drv260x.o
>  obj-$(CONFIG_INPUT_DRV2665_HAPTICS)	+= drv2665.o
>  obj-$(CONFIG_INPUT_DRV2667_HAPTICS)	+= drv2667.o
> diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
> new file mode 100644
> index 0000000..79cac51
> --- /dev/null
> +++ b/drivers/input/misc/ebeam.c
> @@ -0,0 +1,777 @@
> +/******************************************************************************
> + *
> + * eBeam driver
> + *
> + * Copyright (C) 2012-2015 Yann Cantin (yann.cantin@laposte.net)
> + *
> + *	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.
> + *
> + *  based on
> + *
> + *	usbtouchscreen.c by Daniel Ritz <daniel.ritz@gmx.ch>
> + *	aiptek.c (sysfs/settings) by Chris Atenasio <chris@crud.net>
> + *				     Bryan W. Headley <bwheadley@earthlink.net>
> + *
> + *****************************************************************************/
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/math64.h>
> +#include <linux/input.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/usb.h>
> +#include <linux/usb/input.h>
> +#include <asm/unaligned.h>
> +
> +#define DRIVER_AUTHOR	"Yann Cantin <yann.cantin@laposte.net>"
> +#define DRIVER_DESC	"USB eBeam Driver"
> +
> +/* Common values for eBeam devices */
> +#define REPT_SIZE	8	/* packet size            */
> +#define MIN_RAW_X	0	/* raw coordinates ranges */
> +#define MAX_RAW_X	0xFFFF
> +#define MIN_RAW_Y	0
> +#define MAX_RAW_Y	0xFFFF
> +
> +/* Electronics For Imaging, Inc */
> +#define USB_VENDOR_ID_EFI	0x2650
> +
> +/* eBeam hardware :			*/
> +/*	Luidia Classic and Edge		*/
> +/*	Nec NP01Wi1 & NP01Wi2		*/
> +#define USB_DEVICE_ID_EFI_EBEAM_USB1	0x1311
> +/*	From https://github.com/dpiquet	*/
> +/*	Need confirmation		*/
> +#define USB_DEVICE_ID_EFI_EBEAM_USB2	0x1315
> +#define USB_DEVICE_ID_EFI_EBEAM_BT_USB1	0x1313
> +#define USB_DEVICE_ID_EFI_EBEAM_BT_USB2	0x1320
> +
> +#define EBEAM_BTN_TIP	0x1	/* tip    */
> +#define EBEAM_BTN_LIT	0x2	/* little */
> +#define EBEAM_BTN_BIG	0x4	/* big    */
> +
> +/* ebeam settings */
> +struct ebeam_settings {
> +	int min_x;	/* computed coordinates ranges for the input layer */
> +	int max_x;
> +	int min_y;
> +	int max_y;
> +
> +	/* H matrix */
> +	s64 h1;
> +	s64 h2;
> +	s64 h3;
> +	s64 h4;
> +	s64 h5;
> +	s64 h6;
> +	s64 h7;
> +	s64 h8;
> +	s64 h9;
> +};
> +
> +/* ebeam device */
> +struct ebeam_device {
> +	unsigned char		*data;
> +	dma_addr_t		data_dma;
> +	unsigned char		*buffer;
> +	int			buf_len;
> +	struct urb		*irq;
> +	struct usb_interface	*interface;
> +	struct input_dev	*input;
> +	char			name[128];
> +	char			phys[64];
> +	void			*priv;
> +
> +	struct ebeam_settings	cursetting;	/* device's current settings */
> +	struct ebeam_settings	newsetting;	/* ... and new ones          */
> +
> +	bool			calibrated;	/* false : send raw          */
> +						/* true  : send computed     */
> +
> +	u16			raw_x;		/* raw coordinates           */
> +	u16			raw_y;
> +	int			x;		/* computed coordinates      */
> +	int			y;
> +	int			btn_map;	/* internal buttons map      */
> +};
> +
> +/* device types */
> +enum {
> +	DEVTYPE_EBEAM,
> +};
> +
> +static const struct usb_device_id ebeam_devices[] = {
> +	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB1),
> +	 .driver_info = DEVTYPE_EBEAM},
> +	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB2),
> +	 .driver_info = DEVTYPE_EBEAM},
> +	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB1),
> +	 .driver_info = DEVTYPE_EBEAM},
> +	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB2),
> +	 .driver_info = DEVTYPE_EBEAM},
> +	{}
> +};
> +
> +static void ebeam_init_settings(struct ebeam_device *ebeam)
> +{
> +	ebeam->calibrated = false;
> +
> +	/* Init (x,y) min/max to raw ones */
> +	ebeam->cursetting.min_x = ebeam->newsetting.min_x = MIN_RAW_X;
> +	ebeam->cursetting.max_x = ebeam->newsetting.max_x = MAX_RAW_X;
> +	ebeam->cursetting.min_y = ebeam->newsetting.min_y = MIN_RAW_Y;
> +	ebeam->cursetting.max_y = ebeam->newsetting.max_y = MAX_RAW_Y;
> +
> +	/* Safe values for the H matrix (Identity) */
> +	ebeam->cursetting.h1 = ebeam->newsetting.h1 = 1;
> +	ebeam->cursetting.h2 = ebeam->newsetting.h2 = 0;
> +	ebeam->cursetting.h3 = ebeam->newsetting.h3 = 0;
> +
> +	ebeam->cursetting.h4 = ebeam->newsetting.h4 = 0;
> +	ebeam->cursetting.h5 = ebeam->newsetting.h5 = 1;
> +	ebeam->cursetting.h6 = ebeam->newsetting.h6 = 0;
> +
> +	ebeam->cursetting.h7 = ebeam->newsetting.h7 = 0;
> +	ebeam->cursetting.h8 = ebeam->newsetting.h8 = 0;
> +	ebeam->cursetting.h9 = ebeam->newsetting.h9 = 1;
> +}
> +
> +static void ebeam_setup_input(struct ebeam_device *ebeam,
> +			      struct input_dev *input_dev)
> +{
> +	unsigned long flags;
> +
> +	/* Take event lock while modifying parameters */
> +	spin_lock_irqsave(&input_dev->event_lock, flags);
> +
> +	/* Properties */
> +	set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
> +
> +	/* Events generated */
> +	set_bit(EV_KEY, input_dev->evbit);
> +	set_bit(EV_ABS, input_dev->evbit);
> +
> +	/* Keys */
> +	set_bit(BTN_LEFT,	input_dev->keybit);
> +	set_bit(BTN_MIDDLE,	input_dev->keybit);
> +	set_bit(BTN_RIGHT,	input_dev->keybit);
> +
> +	/* Axis */
> +	if (!ebeam->calibrated) {
> +		ebeam->cursetting.min_x = MIN_RAW_X;
> +		ebeam->cursetting.max_x = MAX_RAW_X;
> +		ebeam->cursetting.min_y = MIN_RAW_Y;
> +		ebeam->cursetting.max_y = MAX_RAW_Y;
> +	}
> +
> +	input_set_abs_params(input_dev, ABS_X,
> +			     ebeam->cursetting.min_x, ebeam->cursetting.max_x,
> +			     0, 0);
> +	input_set_abs_params(input_dev, ABS_Y,
> +			     ebeam->cursetting.min_y, ebeam->cursetting.max_y,
> +			     0, 0);
> +
> +	spin_unlock_irqrestore(&input_dev->event_lock, flags);
> +}
> +
> +/*******************************************************************************
> + * sysfs part
> + */
> +
> +/*
> + * screen min/max and H matrix coefs
> + * _get return *current* value
> + * _set set new value
> + */
> +#define DEVICE_MINMAX_ATTR(MM)						       \
> +static ssize_t ebeam_##MM##_get(struct device *dev,			       \
> +				struct device_attribute *attr,		       \
> +				char *buf)				       \
> +{									       \
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
> +									       \
> +	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->cursetting.MM);	       \
> +}									       \
> +static ssize_t ebeam_##MM##_set(struct device *dev,			       \
> +				struct device_attribute *attr,		       \
> +				const char *buf,			       \
> +				size_t count)				       \
> +{									       \
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
> +	int err, MM;							       \
> +									       \
> +	err = kstrtoint(buf, 10, &MM);					       \
> +	if (err)							       \
> +		return err;						       \
> +									       \
> +	ebeam->newsetting.MM = MM;					       \
> +	return count;							       \
> +}									       \
> +static DEVICE_ATTR(MM, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,		       \
> +		   ebeam_##MM##_get,					       \
> +		   ebeam_##MM##_set)

DEVICE_ATTR_RW()?



> +
> +DEVICE_MINMAX_ATTR(min_x);
> +DEVICE_MINMAX_ATTR(max_x);
> +DEVICE_MINMAX_ATTR(min_y);
> +DEVICE_MINMAX_ATTR(max_y);
> +
> +#define DEVICE_H_ATTR(SET_ID)						       \
> +static ssize_t ebeam_h##SET_ID##_get(struct device *dev,		       \
> +				     struct device_attribute *attr,	       \
> +				     char *buf)				       \
> +{									       \
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
> +									       \
> +	return snprintf(buf, PAGE_SIZE, "%lld\n", ebeam->cursetting.h##SET_ID);\
> +}									       \
> +static ssize_t ebeam_h##SET_ID##_set(struct device *dev,		       \
> +				     struct device_attribute *attr,	       \
> +				     const char *buf,			       \
> +				     size_t count)			       \
> +{									       \
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
> +	int err;							       \
> +	u64 h;								       \
> +									       \
> +	err = kstrtoll(buf, 10, &h);					       \
> +	if (err)							       \
> +		return err;						       \
> +									       \
> +	ebeam->newsetting.h##SET_ID = h;				       \
> +	return count;							       \
> +}									       \
> +static DEVICE_ATTR(h##SET_ID, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,	       \
> +		   ebeam_h##SET_ID##_get,				       \
> +		   ebeam_h##SET_ID##_set)

DEVICE_ATTR_RW()?

> +
> +DEVICE_H_ATTR(1);
> +DEVICE_H_ATTR(2);
> +DEVICE_H_ATTR(3);
> +DEVICE_H_ATTR(4);
> +DEVICE_H_ATTR(5);
> +DEVICE_H_ATTR(6);
> +DEVICE_H_ATTR(7);
> +DEVICE_H_ATTR(8);
> +DEVICE_H_ATTR(9);
> +
> +/*
> + * sysfs calibrated
> + * Once H matrix coefs are set, writing 1 to this file triggers
> + * coordinates mapping.
> + * Anything else reset the device to un-calibrated mode,
> + * storing cursetting in newsetting.
> +*/
> +static ssize_t ebeam_calibrated_get(struct device *dev,
> +				    struct device_attribute *attr,
> +				    char *buf)
> +{
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);
> +
> +	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->calibrated);
> +}
> +
> +static ssize_t ebeam_calibrated_set(struct device *dev,
> +				    struct device_attribute *attr,
> +				    const char *buf,
> +				    size_t count)
> +{
> +	struct ebeam_device *ebeam = dev_get_drvdata(dev);
> +	int err, c;
> +
> +	err = kstrtoint(buf, 10, &c);
> +	if (err)
> +		return err;
> +
> +	if (c == 1) {
> +		memcpy(&ebeam->cursetting, &ebeam->newsetting,
> +		       sizeof(struct ebeam_settings));
> +		ebeam->calibrated = true;
> +		ebeam_setup_input(ebeam, ebeam->input);
> +	} else {
> +		memcpy(&ebeam->newsetting, &ebeam->cursetting,
> +		       sizeof(struct ebeam_settings));
> +		ebeam->calibrated = false;
> +		ebeam_setup_input(ebeam, ebeam->input);
> +	}
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR(calibrated, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,
> +		   ebeam_calibrated_get, ebeam_calibrated_set);

DEVICE_ATTR_RW()?

> +
> +static struct attribute *ebeam_attrs[] = {
> +	&dev_attr_min_x.attr,
> +	&dev_attr_min_y.attr,
> +	&dev_attr_max_x.attr,
> +	&dev_attr_max_y.attr,
> +	&dev_attr_h1.attr,
> +	&dev_attr_h2.attr,
> +	&dev_attr_h3.attr,
> +	&dev_attr_h4.attr,
> +	&dev_attr_h5.attr,
> +	&dev_attr_h6.attr,
> +	&dev_attr_h7.attr,
> +	&dev_attr_h8.attr,
> +	&dev_attr_h9.attr,
> +	&dev_attr_calibrated.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group ebeam_attr_group = {
> +	.attrs = ebeam_attrs,
> +};
> +
> +/* IRQ */
> +static int ebeam_read_data(struct ebeam_device *ebeam, unsigned char *pkt)
> +{
> +
> +/*
> + * Packet description : 8 bytes
> + *
> + *  nop packet : FF FF FF FF FF FF FF FF
> + *
> + *  pkt[0] : Sensors
> + *	bit 1 : ultrasound signal (guessed)
> + *	bit 2 : IR signal (tested with a remote...) ;
> + *	readings OK : 0x03 (anything else is a show-stopper)
> + *
> + *  pkt[1] : raw_x low
> + *  pkt[2] : raw_x high
> + *
> + *  pkt[3] : raw_y low
> + *  pkt[4] : raw_y high
> + *
> + *  pkt[5] : fiability ?
> + *	often 0xC0
> + *	> 0x80 : OK
> + *
> + *  pkt[6] :
> + *	buttons state (low 4 bits)
> + *		0x1 = no buttons
> + *		bit 0 : tip (WARNING inversed : 0=pressed)
> + *		bit 1 : ? (always 0 during tests)
> + *		bit 2 : little (1=pressed)
> + *		bit 3 : big (1=pressed)
> + *
> + *	pointer ID : (high 4 bits)
> + *		Tested  : 0x6=wand ;
> + *		Guessed : 0x1=red ; 0x2=blue ; 0x3=green ; 0x4=black ;
> + *			  0x5=eraser
> + *		bit 4 : pointer ID
> + *		bit 5 : pointer ID
> + *		bit 6 : pointer ID
> + *		bit 7 : pointer ID
> + *
> + *
> + *  pkt[7] : fiability ?
> + *	often 0xFF
> + *
> + */
> +
> +	/* Filtering bad/nop packet */
> +	if (pkt[0] != 0x03)
> +		return 0;
> +
> +	ebeam->raw_x = get_unaligned_le16(&pkt[1]);
> +	ebeam->raw_y = get_unaligned_le16(&pkt[3]);
> +
> +	ebeam->btn_map = (!(pkt[6] & 0x1)) |
> +			 ((pkt[6] & 0x4) >> 1) |
> +			 ((pkt[6] & 0x8) >> 1);
> +
> +	return 1;
> +}
> +
> +/*
> + * IRQ
> + * compute screen coordinates from raw
> + * Overflow and negative values are ignored
> + */
> +static bool ebeam_calculate_xy(struct ebeam_device *ebeam)
> +{
> +	/* 64-bits divisions handled by div64_s64 */
> +
> +	s64 scale;
> +
> +	if (!ebeam->calibrated) {
> +		ebeam->x = ebeam->raw_x;
> +		ebeam->y = ebeam->raw_y;
> +	} else {
> +		scale = ebeam->cursetting.h7 * ebeam->raw_x +
> +			ebeam->cursetting.h8 * ebeam->raw_y +
> +			ebeam->cursetting.h9;
> +
> +		/* Who want a division by zero in kernel ? */
> +		if (scale == 0) {
> +			dev_err(&(ebeam->interface)->dev,
> +				"%s - Division by zero, wrong calibration.\n",
> +				__func__);
> +			dev_err(&(ebeam->interface)->dev,
> +				"%s - Resetting to un-calibrated mode.\n",
> +				__func__);
> +			ebeam->calibrated = false;
> +			return 0;
> +		}
> +
> +		/*
> +		 * We *must* round the result, but can't do (int) (v1/v2 + 0.5)
> +		 *
> +		 * (int) (v1/v2 + 0.5) <=> (int) ( (2*v1 + v2)/(2*v2) )
> +		 */
> +		ebeam->x =
> +		    (int)div64_s64((((ebeam->cursetting.h1 * ebeam->raw_x +
> +				      ebeam->cursetting.h2 * ebeam->raw_y +
> +				      ebeam->cursetting.h3) << 1) + scale),
> +				   (scale << 1));
> +		ebeam->y =
> +		    (int)div64_s64((((ebeam->cursetting.h4 * ebeam->raw_x +
> +				      ebeam->cursetting.h5 * ebeam->raw_y +
> +				      ebeam->cursetting.h6) << 1) + scale),
> +				   (scale << 1));
> +
> +		/* check range */
> +		if ((ebeam->x < ebeam->cursetting.min_x) ||
> +		    (ebeam->x > ebeam->cursetting.max_x) ||
> +		    (ebeam->y < ebeam->cursetting.min_y) ||
> +		    (ebeam->y > ebeam->cursetting.max_y))
> +			return 0;
> +	}
> +
> +	return 1;
> +}
> +
> +/* IRQ */
> +static void ebeam_report_input(struct ebeam_device *ebeam)
> +{
> +	input_report_key(ebeam->input, BTN_LEFT,
> +			 (ebeam->btn_map & EBEAM_BTN_TIP));
> +	input_report_key(ebeam->input, BTN_MIDDLE,
> +			 (ebeam->btn_map & EBEAM_BTN_LIT));
> +	input_report_key(ebeam->input, BTN_RIGHT,
> +			 (ebeam->btn_map & EBEAM_BTN_BIG));
> +
> +	input_report_abs(ebeam->input, ABS_X, ebeam->x);
> +	input_report_abs(ebeam->input, ABS_Y, ebeam->y);
> +
> +	input_sync(ebeam->input);
> +}
> +
> +/* IRQ */
> +static void ebeam_process_pkt(struct ebeam_device *ebeam,
> +			      unsigned char *pkt, int len)
> +{
> +	if (!ebeam_read_data(ebeam, pkt))
> +		return;
> +
> +	if (!ebeam_calculate_xy(ebeam))
> +		return;
> +
> +	ebeam_report_input(ebeam);
> +}
> +
> +/* IRQ
> + * handler */
> +static void ebeam_irq(struct urb *urb)
> +{
> +	struct ebeam_device *ebeam = urb->context;
> +	struct device *dev = &ebeam->interface->dev;
> +	int retval;
> +
> +	switch (urb->status) {
> +	case 0:
> +		/* success */
> +		break;
> +	case -ETIME:
> +		/* this urb is timing out */
> +		dev_dbg(dev,
> +			"%s - urb timed out - was the device unplugged?\n",
> +			__func__);
> +		return;
> +	case -ECONNRESET:
> +	case -ENOENT:
> +	case -ESHUTDOWN:
> +	case -EPIPE:
> +		/* this urb is terminated, clean up */
> +		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
> +			__func__, urb->status);
> +		return;
> +	default:
> +		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
> +			__func__, urb->status);
> +		goto exit;
> +	}
> +
> +	ebeam_process_pkt(ebeam, ebeam->data, urb->actual_length);
> +
> +exit:
> +	usb_mark_last_busy(interface_to_usbdev(ebeam->interface));
> +	retval = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (retval)
> +		dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
> +			__func__, retval);
> +}
> +
> +static int ebeam_open(struct input_dev *input)
> +{
> +	struct ebeam_device *ebeam = input_get_drvdata(input);
> +	int r;
> +
> +	ebeam->irq->dev = interface_to_usbdev(ebeam->interface);
> +
> +	r = usb_autopm_get_interface(ebeam->interface) ? -EIO : 0;
> +	if (r < 0)
> +		goto out;
> +
> +	if (usb_submit_urb(ebeam->irq, GFP_KERNEL)) {
> +		r = -EIO;
> +		goto out_put;
> +	}
> +
> +	ebeam->interface->needs_remote_wakeup = 1;
> +out_put:
> +	usb_autopm_put_interface(ebeam->interface);
> +out:
> +	return r;
> +}
> +
> +static void ebeam_close(struct input_dev *input)
> +{
> +	struct ebeam_device *ebeam = input_get_drvdata(input);
> +	int r;
> +
> +	r = usb_autopm_get_interface(ebeam->interface);
> +
> +	usb_kill_urb(ebeam->irq);
> +	ebeam->interface->needs_remote_wakeup = 0;
> +
> +	if (!r)
> +		usb_autopm_put_interface(ebeam->interface);
> +}
> +
> +static int ebeam_suspend(struct usb_interface *intf, pm_message_t message)
> +{
> +	struct ebeam_device *ebeam = usb_get_intfdata(intf);
> +
> +	usb_kill_urb(ebeam->irq);
> +
> +	return 0;
> +}
> +
> +static int ebeam_resume(struct usb_interface *intf)
> +{
> +	struct ebeam_device *ebeam = usb_get_intfdata(intf);
> +	struct input_dev *input = ebeam->input;
> +	int result = 0;
> +
> +	mutex_lock(&input->mutex);
> +	if (input->users)
> +		result = usb_submit_urb(ebeam->irq, GFP_NOIO);
> +	mutex_unlock(&input->mutex);
> +
> +	return result;
> +}
> +
> +static void ebeam_free_buffers(struct usb_device *udev,
> +			       struct ebeam_device *ebeam)
> +{
> +	usb_free_coherent(udev, REPT_SIZE, ebeam->data, ebeam->data_dma);
> +	kfree(ebeam->buffer);
> +}
> +
> +static struct usb_endpoint_descriptor
> +*ebeam_get_input_endpoint(struct usb_host_interface *interface)
> +{
> +	int i;
> +
> +	for (i = 0; i < interface->desc.bNumEndpoints; i++)
> +		if (usb_endpoint_dir_in(&interface->endpoint[i].desc))
> +			return &interface->endpoint[i].desc;
> +
> +	return NULL;
> +}
> +
> +static int ebeam_probe(struct usb_interface *intf,
> +		       const struct usb_device_id *id)
> +{
> +	struct ebeam_device *ebeam;
> +	struct input_dev *input_dev;
> +	struct usb_endpoint_descriptor *endpoint;
> +	struct usb_device *udev = interface_to_usbdev(intf);
> +	int err = -ENOMEM;
> +
> +	endpoint = ebeam_get_input_endpoint(intf->cur_altsetting);
> +	if (!endpoint)
> +		return -ENXIO;
> +
> +	ebeam = kzalloc(sizeof(struct ebeam_device), GFP_KERNEL);
> +	input_dev = input_allocate_device();
> +	if (!ebeam || !input_dev)
> +		goto out_free;
> +
> +	ebeam_init_settings(ebeam);
> +
> +	ebeam->data = usb_alloc_coherent(udev, REPT_SIZE,
> +					 GFP_KERNEL, &ebeam->data_dma);
> +	if (!ebeam->data)
> +		goto out_free;
> +
> +	ebeam->irq = usb_alloc_urb(0, GFP_KERNEL);
> +	if (!ebeam->irq) {
> +		dev_dbg(&intf->dev,
> +			"%s - usb_alloc_urb failed: ebeam->irq\n", __func__);
> +		goto out_free_buffers;
> +	}
> +
> +	ebeam->interface = intf;
> +	ebeam->input = input_dev;
> +
> +	/* setup name */
> +	snprintf(ebeam->name, sizeof(ebeam->name),
> +		 "USB eBeam %04x:%04x",
> +		 le16_to_cpu(udev->descriptor.idVendor),
> +		 le16_to_cpu(udev->descriptor.idProduct));
> +
> +	if (udev->manufacturer || udev->product) {
> +		strlcat(ebeam->name, " (", sizeof(ebeam->name));
> +
> +		if (udev->manufacturer)
> +			strlcat(ebeam->name,
> +				udev->manufacturer,
> +				sizeof(ebeam->name));
> +
> +		if (udev->product) {
> +			if (udev->manufacturer)
> +				strlcat(ebeam->name, " ", sizeof(ebeam->name));
> +			strlcat(ebeam->name,
> +				udev->product,
> +				sizeof(ebeam->name));
> +		}
> +
> +		if (strlcat(ebeam->name, ")", sizeof(ebeam->name))
> +		    >= sizeof(ebeam->name)) {
> +			/* overflowed, closing ) anyway */
> +			ebeam->name[sizeof(ebeam->name) - 2] = ')';
> +		}
> +	}
> +
> +	/* usb tree */
> +	usb_make_path(udev, ebeam->phys, sizeof(ebeam->phys));
> +	strlcat(ebeam->phys, "/input0", sizeof(ebeam->phys));
> +
> +	/* input setup */
> +	input_dev->name = ebeam->name;
> +	input_dev->phys = ebeam->phys;
> +	usb_to_input_id(udev, &input_dev->id);
> +	input_dev->dev.parent = &intf->dev;
> +
> +	input_set_drvdata(input_dev, ebeam);
> +
> +	input_dev->open = ebeam_open;
> +	input_dev->close = ebeam_close;
> +
> +	/* usb urb setup */
> +	if (usb_endpoint_type(endpoint) == USB_ENDPOINT_XFER_INT)
> +		usb_fill_int_urb(ebeam->irq,
> +				 udev,
> +				 usb_rcvintpipe(udev,
> +						endpoint->bEndpointAddress),
> +				 ebeam->data,
> +				 REPT_SIZE,
> +				 ebeam_irq,
> +				 ebeam,
> +				 endpoint->bInterval);
> +	else
> +		usb_fill_bulk_urb(ebeam->irq,
> +				  udev,
> +				  usb_rcvbulkpipe(udev,
> +						  endpoint->bEndpointAddress),
> +				  ebeam->data,
> +				  REPT_SIZE,
> +				  ebeam_irq,
> +				  ebeam);
> +
> +	ebeam->irq->dev = udev;
> +	ebeam->irq->transfer_dma = ebeam->data_dma;
> +	ebeam->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +
> +	/* usb final setup */
> +	usb_set_intfdata(intf, ebeam);
> +
> +	/* sysfs setup */
> +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);

Ick, you just added the sysfs files to the USB device, not your input
device, are you sure you tested this?

And there should be a race-free way to add an attribute group to an
input device, as this is, you are adding them to the device _after_ it
is created, so userspace will not see them at creation time, causing a
race.

thanks,

greg k-h

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Dmitry Torokhov]

On Mon, Jul 20, 2015 at 02:59:56PM -0700, Greg KH wrote:
> On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
> > Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
> 
> > +
> > +	/* sysfs setup */
> > +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
> 
> Ick, you just added the sysfs files to the USB device, not your input
> device, are you sure you tested this?
> 
> And there should be a race-free way to add an attribute group to an
> input device, as this is, you are adding them to the device _after_ it
> is created, so userspace will not see them at creation time, causing a
> race.

No, there are no driver-specific attributed on input devices themselves,
they belong to the actual hardware devices. The input devices only
export standard attributes applicable to every and all input devices
in the system.

Thanks.

-- 
Dmitry

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Greg KH]

On Mon, Jul 20, 2015 at 03:26:40PM -0700, Dmitry Torokhov wrote:
> On Mon, Jul 20, 2015 at 02:59:56PM -0700, Greg KH wrote:
> > On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
> > > Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
> > 
> > > +
> > > +	/* sysfs setup */
> > > +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
> > 
> > Ick, you just added the sysfs files to the USB device, not your input
> > device, are you sure you tested this?
> > 
> > And there should be a race-free way to add an attribute group to an
> > input device, as this is, you are adding them to the device _after_ it
> > is created, so userspace will not see them at creation time, causing a
> > race.
> 
> No, there are no driver-specific attributed on input devices themselves,
> they belong to the actual hardware devices. The input devices only
> export standard attributes applicable to every and all input devices
> in the system.

Then the Documentation in this patch better be fixed up, as it points to
the input device as having these sysfs files :)

But as these are input device attributes, and not USB device interface
attributes, putting them on the USB interface doesn't make much sense,
and as I pointed out, is racy.  Why can't input devices have
driver-specific attributes?  Why does input devices add their own
attributes sometimes (like in psmouse, which does so in a racy way) yet
this driver shouldn't do that?

Hm, nevermind about psmouse, that happens on the parent device too it
seems (a serio device), not the input device, so it is "consistent", but
not something I really like...

thanks,

greg k-h

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Dmitry Torokhov]

On Mon, Jul 20, 2015 at 03:40:33PM -0700, Greg KH wrote:
> On Mon, Jul 20, 2015 at 03:26:40PM -0700, Dmitry Torokhov wrote:
> > On Mon, Jul 20, 2015 at 02:59:56PM -0700, Greg KH wrote:
> > > On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
> > > > Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
> > > 
> > > > +
> > > > +	/* sysfs setup */
> > > > +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
> > > 
> > > Ick, you just added the sysfs files to the USB device, not your input
> > > device, are you sure you tested this?
> > > 
> > > And there should be a race-free way to add an attribute group to an
> > > input device, as this is, you are adding them to the device _after_ it
> > > is created, so userspace will not see them at creation time, causing a
> > > race.
> > 
> > No, there are no driver-specific attributed on input devices themselves,
> > they belong to the actual hardware devices. The input devices only
> > export standard attributes applicable to every and all input devices
> > in the system.
> 
> Then the Documentation in this patch better be fixed up, as it points to
> the input device as having these sysfs files :)
> 
> But as these are input device attributes, and not USB device interface
> attributes, putting them on the USB interface doesn't make much sense,
> and as I pointed out, is racy.  Why can't input devices have
> driver-specific attributes?  Why does input devices add their own
> attributes sometimes (like in psmouse, which does so in a racy way) yet
> this driver shouldn't do that?
> 
> Hm, nevermind about psmouse, that happens on the parent device too it
> seems (a serio device), not the input device, so it is "consistent", but
> not something I really like...

I think it is historical as quite often they (attributes) affect the
hardware itself, not behavior of input interface. And so they were
always placed on hardware level, not input device level.

Anyway, I do not think you are going to win your war on sysfs attributes
created post-device creation. We just need to recognize that there are
attributes that are created by the driver when it is bound to the
device. Maybe we need to revisit the idea about emitting special uevent
when driver is fully bound to a device and interested userspace can
start using it.

Thanks.

-- 
Dmitry

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Yann Cantin]

Hi,

Le 21/07/2015 00:40, Greg KH a écrit :
> On Mon, Jul 20, 2015 at 03:26:40PM -0700, Dmitry Torokhov wrote:
>> On Mon, Jul 20, 2015 at 02:59:56PM -0700, Greg KH wrote:
>>> On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
>>>> Signed-off-by: Yann Cantin <yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org>
>>>
>>>> +
>>>> +	/* sysfs setup */
>>>> +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
>>>
>>> Ick, you just added the sysfs files to the USB device, not your input
>>> device, are you sure you tested this?
>>>
>>> And there should be a race-free way to add an attribute group to an
>>> input device, as this is, you are adding them to the device _after_ it
>>> is created, so userspace will not see them at creation time, causing a
>>> race.
>>
>> No, there are no driver-specific attributed on input devices themselves,
>> they belong to the actual hardware devices. The input devices only
>> export standard attributes applicable to every and all input devices
>> in the system.
>
> Then the Documentation in this patch better be fixed up, as it points to
> the input device as having these sysfs files :)
>
> But as these are input device attributes, and not USB device interface
> attributes, putting them on the USB interface doesn't make much sense,

To sum up : these attributes are USB device's not input's, only indirectly
accessed via inputXX/device/, and they only modify the driver's behavior.
So, it make sense to correct the documentation to point at
/sys/bus/usb/drivers/ebeam/X-X:1.0/. Right ?

thanks,

-- 
Yann Cantin
A4FEB47F
--

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Yann Cantin]

Hi,

Le 20/07/2015 23:59, Greg KH a écrit :
> On Mon, Jul 20, 2015 at 11:03:19PM +0200, Yann Cantin wrote:
>> diff --git a/Documentation/ABI/testing/sysfs-driver-ebeam b/Documentation/ABI/testing/sysfs-driver-ebeam
>> +++ b/Documentation/ABI/testing/sysfs-driver-ebeam
>> @@ -0,0 +1,53 @@
>> +What:		/sys/class/input/inputXX/device/min_x
>> +		/sys/class/input/inputXX/device/min_y
>> +		/sys/class/input/inputXX/device/max_x
>> +		/sys/class/input/inputXX/device/max_y
>> +What:		/sys/class/input/inputXX/device/h[1..9]
>> +What:		/sys/class/input/inputXX/device/calibrated
>
>
> What tool(s) use these sysfs files?  Don't we already have "normal"
> events for these types of things such that we don't have to make up new
> sysfs files for these?

The ebeam_calibrator tool is there : http://ebeam.tuxfamily.org.

I agree this can be a problem : this driver is totally useless without a
userspace dedicated calibration tool.

By nature these device's coordinate system can't be mapped to screen via
trivial transformations, such as scaling, flipping and rotating, hence the
special calibration and mapping procedures. I choose to use an homography
transformation as it is more robust and faster than linear interpolation
in this case. And anyway, it requires 9 calibration data and xy range
parameters.

I haven't found any existing tools performing that : xinput_calibrator
(witch ebeam_calibrator is based on) and other touchscreen calibration
tools can't do much more than trivial transformations.


>> +static DEVICE_ATTR(MM, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,		       \
>> +		   ebeam_##MM##_get,					       \
>> +		   ebeam_##MM##_set)
>
> DEVICE_ATTR_RW()?

Ok, will do.


>> +	/* sysfs setup */
>> +	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
>
> Ick, you just added the sysfs files to the USB device, not your input
> device, are you sure you tested this?

Yes, "run fine since 3.3.6, both x86_32 and 64.".

thanks,

-- 
Yann Cantin
A4FEB47F
--

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Oliver Neukum]

On Mon, 2015-07-20 at 23:03 +0200, Yann Cantin wrote:
> Signed-off-by: Yann Cantin <yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org>
> ---
>  Documentation/ABI/testing/sysfs-driver-ebeam |  53 ++
>  drivers/input/misc/Kconfig                   |  22 +
>  drivers/input/misc/Makefile                  |   1 +
>  drivers/input/misc/ebeam.c                   | 777 +++++++++++++++++++++++++++
>  4 files changed, 853 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-driver-ebeam
>  create mode 100644 drivers/input/misc/ebeam.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ebeam b/Documentation/ABI/testing/sysfs-driver-ebeam
> new file mode 100644
> index 0000000..6873db5
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-driver-ebeam
> @@ -0,0 +1,53 @@
> +What:		/sys/class/input/inputXX/device/min_x
> +		/sys/class/input/inputXX/device/min_y
> +		/sys/class/input/inputXX/device/max_x
> +		/sys/class/input/inputXX/device/max_y
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org
> +		linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Reading from these files return the actually used range values of
> +		the reported coordinates.
> +		Writing to these files preset these range values.
> +		See below for the calibration procedure.
> +
> +What:		/sys/class/input/inputXX/device/h[1..9]
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org
> +		linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Reading from these files return the 3x3 transformation matrix elements
> +		actually used, in row-major.
> +		Writing to these files preset these elements values.
> +		See below for the calibration procedure.
> +
> +What:		/sys/class/input/inputXX/device/calibrated
> +Date:		Jul 2015
> +Kernel Version:	4.1
> +Contact:	yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org
> +		linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +Description:
> +		Reading from this file :
> +		- Return 0 if the driver is in "un-calibrated" mode : it actually send
> +		  raw coordinates in the device's internal coordinates system.
> +		- Return 1 if the driver is in "calibrated" mode : it send computed coordinates
> +		  that (hopefully) matches the screen's coordinates system.
> +		Writing 1 to this file enable the "calibrated" mode, 0 reset the driver in
> +		"un-calibrated" mode.
> +
> +Calibration procedure :
> +
> +When loaded, the driver is in "un-calibrated" mode : it send device's raw coordinates
> +in the [0..65535]x[0..65535] range, the transformation matrix is the identity.
> +
> +A calibration program have to compute a homography transformation matrix that convert
> +the device's raw coordinates to the matching screen's ones.
> +It then write to the appropriate sysfs files the computed values, pre-setting the
> +driver's parameters : xy range, and the matrix's elements.
> +When all values are passed, it write 1 to the calibrated sysfs file to enable the "calibrated" mode.
> +
> +Warning : The parameters aren't used until 1 is writen to the calibrated sysfs file.
> +
> +Writing 0 to the calibrated sysfs file reset the driver in "un-calibrated" mode.
> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index d4f0a81..22c46a4 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -103,6 +103,28 @@ config INPUT_E3X0_BUTTON
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called e3x0_button.
>  
> +config INPUT_EBEAM_USB
> +	tristate "USB eBeam driver"
> +	depends on USB_ARCH_HAS_HCD
> +	select USB
> +	help
> +	  Say Y here if you have a USB eBeam pointing device and want to
> +	  use it without any proprietary user space tools.
> +
> +	  Have a look at <http://ebeam.tuxfamily.org/> for
> +	  a usage description and the required user-space tools.
> +
> +	  Supported devices :
> +	    - Luidia eBeam Classic Projection and eBeam Edge Projection
> +	    - Nec NP01Wi1 & NP01Wi2 interactive solution
> +
> +	  Supposed working devices, need test, may lack functionality :
> +	    - Luidia eBeam Edge Whiteboard and eBeam Engage
> +	    - Hitachi Starboard FX-63, FX-77, FX-82, FX-77GII
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ebeam.
> +
>  config INPUT_PCSPKR
>  	tristate "PC Speaker support"
>  	depends on PCSPKR_PLATFORM
> diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
> index 53df07d..125f8a9 100644
> --- a/drivers/input/misc/Makefile
> +++ b/drivers/input/misc/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
>  obj-$(CONFIG_INPUT_DA9063_ONKEY)	+= da9063_onkey.o
>  obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
>  obj-$(CONFIG_INPUT_E3X0_BUTTON)		+= e3x0-button.o
> +obj-$(CONFIG_INPUT_EBEAM_USB)		+= ebeam.o
>  obj-$(CONFIG_INPUT_DRV260X_HAPTICS)	+= drv260x.o
>  obj-$(CONFIG_INPUT_DRV2665_HAPTICS)	+= drv2665.o
>  obj-$(CONFIG_INPUT_DRV2667_HAPTICS)	+= drv2667.o
> diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
> new file mode 100644
> index 0000000..79cac51
> --- /dev/null
> +++ b/drivers/input/misc/ebeam.c
> @@ -0,0 +1,777 @@
> +/******************************************************************************
> + *
> + * eBeam driver
> + *
> + * Copyright (C) 2012-2015 Yann Cantin (yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org)
> + *
> + *	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.
> + *
> + *  based on
> + *
> + *	usbtouchscreen.c by Daniel Ritz <daniel.ritz-OI3hZJvNYWs@public.gmane.org>
> + *	aiptek.c (sysfs/settings) by Chris Atenasio <chris-v4AJ0sPprEc@public.gmane.org>
> + *				     Bryan W. Headley <bwheadley-ihVZJaRskl1bRRN4PJnoQQ@public.gmane.org>
> + *
> + *****************************************************************************/
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/math64.h>
> +#include <linux/input.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/usb.h>
> +#include <linux/usb/input.h>
> +#include <asm/unaligned.h>
> +
> +#define DRIVER_AUTHOR	"Yann Cantin <yann.cantin-QFKgK+z4sOrR7s880joybQ@public.gmane.org>"
> +#define DRIVER_DESC	"USB eBeam Driver"
> +
> +/* Common values for eBeam devices */
> +#define REPT_SIZE	8	/* packet size            */
> +#define MIN_RAW_X	0	/* raw coordinates ranges */
> +#define MAX_RAW_X	0xFFFF
> +#define MIN_RAW_Y	0
> +#define MAX_RAW_Y	0xFFFF
> +
> +/* Electronics For Imaging, Inc */
> +#define USB_VENDOR_ID_EFI	0x2650

You are defining these IDs twice. That is not good.

	Regards
		Oliver

Re: [RFC ebeam PATCH 2/2] input: misc: New USB eBeam input driver

[Yann Cantin]

Hi,

Le 21/07/2015 10:19, Oliver Neukum a écrit :
> On Mon, 2015-07-20 at 23:03 +0200, Yann Cantin wrote:

>> diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
>> new file mode 100644
>> index 0000000..79cac51
>> --- /dev/null
>> +++ b/drivers/input/misc/ebeam.c

>> +/* Electronics For Imaging, Inc */
>> +#define USB_VENDOR_ID_EFI	0x2650
>
> You are defining these IDs twice. That is not good.

Is it okay to do this :

#if !defined(CONFIG_INPUT_EBEAM_USB)
#define USB_VENDOR_ID_EFI	0x2650
#...
#endif

so that the driver can also be build outside the kernel tree ?

thanks,

-- 
Yann Cantin
A4FEB47F
--