[RFC ebeam PATCH v2 0/3] new USB eBeam input driver

[RFC ebeam PATCH v2 0/3] new USB eBeam input driver

[Yann Cantin]

Hi,

Second test-drive for a new USB input driver for eBeam
devices.

Following Dmitry's advice, i've remove device specific infrastructure.

Currently, only the Luidia eBeam classic projection model is supported.

Patch 1 and 2 are here to let the ebeam driver be choose to handle
the device instead of the generic-usb hid one (totally useless).

Patch 3 is the actual driver.
Some things to consider :
- I'm not familiar with kernel coding (i've based my work on
  usbtouchscreen.c) so the code certainly contain flaws.
- There's 2 64/64-bits divisions needed, don't know how to handle that the
  right way to be efficient and portable.
- There's 14 custom sysfs files. Yes.

The module run fine with a 3.3.6 and a 3.5.0 kernel.

Thanks for your help.

[RFC ebeam PATCH v2 1/3] hid: hid-ids.h: Add vendor and device ID for eBeam classic device.

[Yann Cantin]

Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
---
 drivers/hid/hid-ids.h |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 1dcb76f..b985059 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -271,6 +271,9 @@
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7349	0x7349
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001	0xa001
 
+#define USB_VENDOR_ID_EFI		0x2650
+#define USB_DEVICE_ID_EFI_CLASSIC	0x1311
+
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061
 
-- 
1.7.10

[RFC ebeam PATCH v2 2/3] hid: hid-core.c: Blackist eBeam classic device.

[Yann Cantin]

Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
---
 drivers/hid/hid-core.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 60ea284..b1ed8ee 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1908,6 +1908,9 @@ 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_CLASSIC) },
+#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) },
-- 
1.7.10

[RFC ebeam PATCH v2 3/3] input: misc: New USB eBeam input driver.

[Yann Cantin]

Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
---
 drivers/input/misc/Kconfig  |   16 +
 drivers/input/misc/Makefile |    1 +
 drivers/input/misc/ebeam.c  |  760 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 777 insertions(+)
 create mode 100644 drivers/input/misc/ebeam.c

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 7c0f1ec..1e575e4 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -83,6 +83,22 @@ config INPUT_BMA150
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma150.
 
+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://sourceforge.net/projects/ebeam/> for
+	  a usage description and the required user-space tools.
+
+	  Currently, only the Classic Projection model is supported.
+
+	  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 83fe6f5..2aa9813 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_INPUT_CMA3000_I2C)		+= cma3000_d0x_i2c.o
 obj-$(CONFIG_INPUT_COBALT_BTNS)		+= cobalt_btns.o
 obj-$(CONFIG_INPUT_DA9052_ONKEY)	+= da9052_onkey.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
+obj-$(CONFIG_INPUT_EBEAM_USB)		+= ebeam.o
 obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o
 obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
new file mode 100644
index 0000000..9c698a3
--- /dev/null
+++ b/drivers/input/misc/ebeam.c
@@ -0,0 +1,760 @@
+/******************************************************************************
+ *
+ * eBeam driver
+ *
+ * Copyright (C) 2012 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/input.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+#include <linux/hid.h>
+
+#define DRIVER_VERSION	"v0.7"
+#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_X	0		/* raw coordinates ranges */
+#define MAX_X	0xFFFF
+#define MIN_Y	0
+#define MAX_Y	0xFFFF
+
+
+#define USB_VENDOR_ID_EFI	   0x2650   /* Electronics For Imaging, Inc   */
+#define USB_DEVICE_ID_EFI_CLASSIC  0x1311   /* Classic projection "La banane" */
+
+#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;
+	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			 X, Y;		/* raw coordinates	     */
+	int			 x, y;		/* computed coordinates      */
+	int			 btn_map;	/* internal buttons map      */
+};
+
+
+/* device types */
+enum {
+	DEVTYPE_CLASSIC,
+};
+
+static const struct usb_device_id ebeam_devices[] = {
+	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_CLASSIC),
+			.driver_info = DEVTYPE_CLASSIC},
+	{}
+};
+
+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_X;
+	ebeam->cursetting.max_x = ebeam->newsetting.max_x = MAX_X;
+	ebeam->cursetting.min_y = ebeam->newsetting.min_y = MIN_Y;
+	ebeam->cursetting.max_y = ebeam->newsetting.max_y = MAX_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_X;
+		ebeam->cursetting.max_x = MAX_X;
+		ebeam->cursetting.min_y = MIN_Y;
+		ebeam->cursetting.max_y = MAX_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_IRUGO | S_IWUGO,				       \
+		   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_IRUGO | S_IWUGO,			       \
+		   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_IRUGO | S_IWUGO,
+		   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] : X low
+ *  pkt[2] : X high
+ *
+ *  pkt[3] : Y low
+ *  pkt[4] : 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 : (hight 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->X = (pkt[2] << 8) | pkt[1];
+	ebeam->Y = (pkt[4] << 8) | pkt[3];
+
+	ebeam->btn_map = (!(pkt[6] & 0x1))	|
+			 ((pkt[6] & 0x4) >> 1)	|
+			 ((pkt[6] & 0x8) >> 1);
+
+	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
+ * compute screen coordinates from raw
+ * Overflow and negative values are user space's problem
+ */
+static bool ebeam_calculate_xy(struct ebeam_device *ebeam)
+{
+	/* TODO : check if u64 division is available on all plateform */
+
+	s64 scale;
+
+	if (!ebeam->calibrated) {
+		ebeam->x = ebeam->X;
+		ebeam->y = ebeam->Y;
+	} else {
+		scale = ebeam->cursetting.h7 * ebeam->X +
+			ebeam->cursetting.h8 * ebeam->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 not with (int) (v1/v2 + 0.5)
+		 *
+		 * (int) (v1/v2 + 0.5) <=> (int) ( (2*v1 + v2)/(2*v2) )
+		 */
+		ebeam->x = (int) ((((ebeam->cursetting.h1 * ebeam->X +
+				     ebeam->cursetting.h2 * ebeam->Y +
+				     ebeam->cursetting.h3) << 1) + scale) /
+				     (scale << 1));
+		ebeam->y = (int) ((((ebeam->cursetting.h4 * ebeam->X +
+				     ebeam->cursetting.h5 * ebeam->Y +
+				     ebeam->cursetting.h6) << 1) + scale) /
+				     (scale << 1));
+	}
+
+	return 1;
+}
+
+/* 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;
+
+	usb_kill_urb(ebeam->irq);
+
+	r = usb_autopm_get_interface(ebeam->interface);
+	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 int ebeam_reset_resume(struct usb_interface *intf)
+{
+	struct ebeam_device *ebeam = usb_get_intfdata(intf);
+	struct input_dev *input = ebeam->input;
+	int err = 0;
+
+	/* restart IO if needed */
+	mutex_lock(&input->mutex);
+	if (input->users)
+		err = usb_submit_urb(ebeam->irq, GFP_NOIO);
+	mutex_unlock(&input->mutex);
+
+	return err;
+}
+
+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));
+		}
+
+		strlcat(ebeam->name, ")", sizeof(ebeam->name));
+	}
+
+	/* 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;
+
+	/* input final setup */
+	err = input_register_device(ebeam->input);
+	if (err) {
+		dev_dbg(&intf->dev,
+			"%s - input_register_device failed, err: %d\n",
+			__func__, err);
+		goto out_free_urb;
+	}
+
+	ebeam_setup_input(ebeam, input_dev);
+
+	/* 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_unregister_input;
+	}
+
+	return 0;
+
+out_unregister_input:
+	input_unregister_device(input_dev);
+	input_dev = NULL;
+out_free_urb:
+	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_reset_resume,
+	.id_table		= ebeam_devices,
+	.supports_autosuspend	= 1,
+};
+
+module_usb_driver(ebeam_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
-- 
1.7.10

Re: [RFC ebeam PATCH v2 3/3] input: misc: New USB eBeam input driver.

[Jiri Kosina]

On Thu, 2 Aug 2012, Yann Cantin wrote:

> Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
> ---
>  drivers/input/misc/Kconfig  |   16 +
>  drivers/input/misc/Makefile |    1 +
>  drivers/input/misc/ebeam.c  |  760 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 777 insertions(+)
>  create mode 100644 drivers/input/misc/ebeam.c
> 
> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index 7c0f1ec..1e575e4 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -83,6 +83,22 @@ config INPUT_BMA150
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called bma150.
>  
> +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://sourceforge.net/projects/ebeam/> for
> +	  a usage description and the required user-space tools.
> +
> +	  Currently, only the Classic Projection model is supported.
> +
> +	  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 83fe6f5..2aa9813 100644
> --- a/drivers/input/misc/Makefile
> +++ b/drivers/input/misc/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_INPUT_CMA3000_I2C)		+= cma3000_d0x_i2c.o
>  obj-$(CONFIG_INPUT_COBALT_BTNS)		+= cobalt_btns.o
>  obj-$(CONFIG_INPUT_DA9052_ONKEY)	+= da9052_onkey.o
>  obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
> +obj-$(CONFIG_INPUT_EBEAM_USB)		+= ebeam.o
>  obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o
>  obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
>  obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
> diff --git a/drivers/input/misc/ebeam.c b/drivers/input/misc/ebeam.c
> new file mode 100644
> index 0000000..9c698a3
> --- /dev/null
> +++ b/drivers/input/misc/ebeam.c
> @@ -0,0 +1,760 @@
> +/******************************************************************************
> + *
> + * eBeam driver
> + *
> + * Copyright (C) 2012 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/input.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/usb.h>
> +#include <linux/usb/input.h>
> +#include <linux/hid.h>

As this driver is not a HID bus driver, why do you need this include?

> +
> +#define DRIVER_VERSION	"v0.7"

I don't think we need to be tracking driver versions for newly submitted 
drivers, git is much better at tracking changes.

> +#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_X	0		/* raw coordinates ranges */
> +#define MAX_X	0xFFFF
> +#define MIN_Y	0
> +#define MAX_Y	0xFFFF
> +
> +
> +#define USB_VENDOR_ID_EFI	   0x2650   /* Electronics For Imaging, Inc   */
> +#define USB_DEVICE_ID_EFI_CLASSIC  0x1311   /* Classic projection "La banane" */
> +
> +#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;
> +	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			 X, Y;		/* raw coordinates	     */
> +	int			 x, y;		/* computed coordinates      */

X,x being different fields seems confusing to me. How about, let's say, x, 
raw_x?

> +	int			 btn_map;	/* internal buttons map      */
> +};
> +
> +
> +/* device types */
> +enum {
> +	DEVTYPE_CLASSIC,
> +};
> +
> +static const struct usb_device_id ebeam_devices[] = {
> +	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_CLASSIC),
> +			.driver_info = DEVTYPE_CLASSIC},
> +	{}
> +};
> +
> +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_X;
> +	ebeam->cursetting.max_x = ebeam->newsetting.max_x = MAX_X;
> +	ebeam->cursetting.min_y = ebeam->newsetting.min_y = MIN_Y;
> +	ebeam->cursetting.max_y = ebeam->newsetting.max_y = MAX_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_X;
> +		ebeam->cursetting.max_x = MAX_X;
> +		ebeam->cursetting.min_y = MIN_Y;
> +		ebeam->cursetting.max_y = MAX_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_IRUGO | S_IWUGO,				       \
> +		   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_IRUGO | S_IWUGO,			       \
> +		   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);

You are adding a number of sysfs files. If they are really necessary, 
you'll probably need to document those in Documentation/ABI.

> +
> +/*
> + * 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_IRUGO | S_IWUGO,
> +		   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] : X low
> + *  pkt[2] : X high
> + *
> + *  pkt[3] : Y low
> + *  pkt[4] : 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 : (hight 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->X = (pkt[2] << 8) | pkt[1];
> +	ebeam->Y = (pkt[4] << 8) | pkt[3];
> +
> +	ebeam->btn_map = (!(pkt[6] & 0x1))	|
> +			 ((pkt[6] & 0x4) >> 1)	|
> +			 ((pkt[6] & 0x8) >> 1);
> +
> +	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
> + * compute screen coordinates from raw
> + * Overflow and negative values are user space's problem
> + */
> +static bool ebeam_calculate_xy(struct ebeam_device *ebeam)
> +{
> +	/* TODO : check if u64 division is available on all plateform */
> +
> +	s64 scale;
> +
> +	if (!ebeam->calibrated) {
> +		ebeam->x = ebeam->X;
> +		ebeam->y = ebeam->Y;
> +	} else {
> +		scale = ebeam->cursetting.h7 * ebeam->X +
> +			ebeam->cursetting.h8 * ebeam->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 not with (int) (v1/v2 + 0.5)
> +		 *
> +		 * (int) (v1/v2 + 0.5) <=> (int) ( (2*v1 + v2)/(2*v2) )
> +		 */
> +		ebeam->x = (int) ((((ebeam->cursetting.h1 * ebeam->X +
> +				     ebeam->cursetting.h2 * ebeam->Y +
> +				     ebeam->cursetting.h3) << 1) + scale) /
> +				     (scale << 1));
> +		ebeam->y = (int) ((((ebeam->cursetting.h4 * ebeam->X +
> +				     ebeam->cursetting.h5 * ebeam->Y +
> +				     ebeam->cursetting.h6) << 1) + scale) /
> +				     (scale << 1));
> +	}
> +
> +	return 1;
> +}
> +
> +/* 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;
> +
> +	usb_kill_urb(ebeam->irq);
> +
> +	r = usb_autopm_get_interface(ebeam->interface);
> +	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 int ebeam_reset_resume(struct usb_interface *intf)
> +{
> +	struct ebeam_device *ebeam = usb_get_intfdata(intf);
> +	struct input_dev *input = ebeam->input;
> +	int err = 0;
> +
> +	/* restart IO if needed */
> +	mutex_lock(&input->mutex);
> +	if (input->users)
> +		err = usb_submit_urb(ebeam->irq, GFP_NOIO);
> +	mutex_unlock(&input->mutex);
> +
> +	return err;
> +}
> +
> +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));
> +		}
> +
> +		strlcat(ebeam->name, ")", sizeof(ebeam->name));
> +	}

I'd suggest checking the length, making sure that you don't overflow the 
->name buffer.

> +
> +	/* 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;
> +
> +	/* input final setup */
> +	err = input_register_device(ebeam->input);
> +	if (err) {
> +		dev_dbg(&intf->dev,
> +			"%s - input_register_device failed, err: %d\n",
> +			__func__, err);
> +		goto out_free_urb;
> +	}
> +
> +	ebeam_setup_input(ebeam, input_dev);
> +
> +	/* 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_unregister_input;
> +	}
> +
> +	return 0;
> +
> +out_unregister_input:
> +	input_unregister_device(input_dev);
> +	input_dev = NULL;
> +out_free_urb:
> +	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_reset_resume,
> +	.id_table		= ebeam_devices,
> +	.supports_autosuspend	= 1,
> +};
> +
> +module_usb_driver(ebeam_driver);
> +
> +MODULE_AUTHOR(DRIVER_AUTHOR);
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL");
> +
> 

-- 
Jiri Kosina
SUSE Labs

Re: [RFC ebeam PATCH v2 3/3] input: misc: New USB eBeam input driver.

[Yann Cantin]

Hi,

>> +#include <linux/hid.h>
> 
> As this driver is not a HID bus driver, why do you need this include?

Cinder, removed

>> +#define DRIVER_VERSION	"v0.7"
> 
> I don't think we need to be tracking driver versions for newly submitted 
> drivers, git is much better at tracking changes.

Old habit, removed.

>> +	u16			 X, Y;		/* raw coordinates	     */
>> +	int			 x, y;		/* computed coordinates      */
> 
> X,x being different fields seems confusing to me. How about, let's say, x, 
> raw_x?

Done.
 
>> +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);
> 
> You are adding a number of sysfs files. If they are really necessary, 
> you'll probably need to document those in Documentation/ABI.

Will do, in testing i suppose.

BTW : The driver need lot of parameters to be passed from user-space calibration
tool. The best way to do it isn't decided yet : one sysfs file per parameter, or
one sysfs file for all, with a big sscanf parsing. Any idea ?

>> +		strlcat(ebeam->name, ")", sizeof(ebeam->name));
> 
> I'd suggest checking the length, making sure that you don't overflow the 
> ->name buffer.

Something like this ? :

if (strlcat(ebeam->name, ")", sizeof(ebeam->name))>=sizeof(ebeam->name)) {
	// overflowed, closing ) anyway
	ebeam->name[sizeof(ebeam->name)-2] = ')';

Thanks.
-- 
Yann Cantin
A4FEB47F
--

Re: [RFC ebeam PATCH v2 3/3] input: misc: New USB eBeam input driver.

[Jiri Kosina]

On Fri, 3 Aug 2012, Yann Cantin wrote:

> >> +#include <linux/hid.h>
> > 
> > As this driver is not a HID bus driver, why do you need this include?
> 
> Cinder, removed
> 
> >> +#define DRIVER_VERSION	"v0.7"
> > 
> > I don't think we need to be tracking driver versions for newly submitted 
> > drivers, git is much better at tracking changes.
> 
> Old habit, removed.
> 
> >> +	u16			 X, Y;		/* raw coordinates	     */
> >> +	int			 x, y;		/* computed coordinates      */
> > 
> > X,x being different fields seems confusing to me. How about, let's say, x, 
> > raw_x?
> 
> Done.
>  
> >> +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);
> > 
> > You are adding a number of sysfs files. If they are really necessary, 
> > you'll probably need to document those in Documentation/ABI.
> 
> Will do, in testing i suppose.
> 
> BTW : The driver need lot of parameters to be passed from user-space calibration
> tool. The best way to do it isn't decided yet : one sysfs file per parameter, or
> one sysfs file for all, with a big sscanf parsing. Any idea ?

Sysfs always had a rule one value per file, so please stick to that.

> >> +		strlcat(ebeam->name, ")", sizeof(ebeam->name));
> > 
> > I'd suggest checking the length, making sure that you don't overflow the 
> > ->name buffer.
> 
> Something like this ? :
> 
> if (strlcat(ebeam->name, ")", sizeof(ebeam->name))>=sizeof(ebeam->name)) {
> 	// overflowed, closing ) anyway
> 	ebeam->name[sizeof(ebeam->name)-2] = ')';

Some variation on that, yes.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [RFC ebeam PATCH v2 0/3] new USB eBeam input driver

[Jiri Kosina]

On Thu, 2 Aug 2012, Yann Cantin wrote:

> Second test-drive for a new USB input driver for eBeam
> devices.
> 
> Following Dmitry's advice, i've remove device specific infrastructure.
> 
> Currently, only the Luidia eBeam classic projection model is supported.
> 
> Patch 1 and 2 are here to let the ebeam driver be choose to handle
> the device instead of the generic-usb hid one (totally useless).

Just merge 1 and 2 together, not necessary to have two commits because of 
that.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [RFC ebeam PATCH v2 0/3] new USB eBeam input driver

[Yann Cantin]

Hi,

Le 02/08/2012 16:16, Jiri Kosina a écrit :
>> Patch 1 and 2 are here to let the ebeam driver be choose to handle
>> the device instead of the generic-usb hid one (totally useless).
> 
> Just merge 1 and 2 together, not necessary to have two commits because of 
> that.

Ok, will do that for the next iteration of the patchset (i don't think
i need to resubmit now with this change only, no?)

Thanks.
-- 
Yann Cantin
A4FEB47F
--