On Tue, Jul 21, 2015 at 03:07:14PM -0400, Stephen Chandler Paul wrote: > Debugging input devices, specifically laptop touchpads, can be tricky > without having the physical device handy. Here we try to remedy that > with ps2emu. This module allows an application to connect to a character > device provided by the kernel, and simulate any PS/2 device. In > combination with userspace programs that can record PS/2 devices and > replay them through the /dev/ps2emu device, this allows developers to > debug driver issues on the PS/2 level with devices simply by requesting > a recording from the user experiencing the issue without having to have > the physical hardware in front of them. > > Signed-off-by: Stephen Chandler Paul <[email protected]> > Reviewed-by: Benjamin Tissoires <[email protected]> > --- > Documentation/input/ps2emu.txt | 72 ++++++++++++ > MAINTAINERS | 6 + > drivers/input/serio/Kconfig | 10 ++ > drivers/input/serio/Makefile | 1 + > drivers/input/serio/ps2emu.c | 253 > +++++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/ps2emu.h | 42 +++++++ > 6 files changed, 384 insertions(+) > create mode 100644 Documentation/input/ps2emu.txt > create mode 100644 drivers/input/serio/ps2emu.c > create mode 100644 include/uapi/linux/ps2emu.h > > diff --git a/Documentation/input/ps2emu.txt b/Documentation/input/ps2emu.txt > new file mode 100644 > index 0000000..560298c > --- /dev/null > +++ b/Documentation/input/ps2emu.txt > @@ -0,0 +1,72 @@ > + The ps2emu Protocol > + (c) 2015 Stephen Chandler Paul <[email protected]> > + Sponsored by Red Hat > +-------------------------------------------------------------------------------- > + > +1. Introduction > +~~~~~~~~~~~~~~~ > + This module is intended to try to make the lives of input driver developers > +easier by allowing them to test various PS/2 devices (mainly the various > +touchpads found on laptops) without having to have the physical device in > front > +of them. ps2emu accomplishes this by allowing any privileged userspace > program > +to directly interact with the kernel's serio driver and pretend to be a PS/2 > +device. > + > +2. Usage overview > +~~~~~~~~~~~~~~~~~ > + In order to interact with the ps2emu kernel module, one simply opens the > +/dev/ps2emu character device in their applications. Commands are sent to the > +kernel module by writing to the device, and any data received from the serio > +driver is read as-is from the /dev/ps2emu device. All of the structures and > +macros you need to interact with the device are defined in <linux/ps2emu.h>. > + > +3. Command Structure > +~~~~~~~~~~~~~~~~~~~~ > + The struct used for sending commands to /dev/ps2emu is as follows: > + > + struct ps2emu_cmd { > + __u8 type; > + __u8 data; > + }; > + > + "type" describes the type of command that is being sent. This can be any > one > +of the PS2EMU_CMD macros defined in <linux/ps2emu.h>. "data" is the argument > +that goes along with the command. In the event that the command doesn't have > an > +argument, this field can be left untouched and will be ignored by the kernel. > +Each command should be sent by writing the struct directly to the character > +device. In the event that the command you send is invalid, an error will be > +returned by the character device and a more descriptive error will be printed > +to the kernel log. Only one command can be sent at a time, any additional > data > +written to the character device after the initial command will be ignored. > + To close the virtual PS/2 port, just close /dev/ps2emu. > + > +4. Commands > +~~~~~~~~~~~ > + > +4.1 PS2EMU_CMD_REGISTER > +~~~~~~~~~~~~~~~~~~~~~~~ > + Registers the port with the serio driver and begins transmitting data back > and > +forth. Registration can only be performed once a port type is set with > +PS2EMU_CMD_SET_PORT_TYPE. Has no argument. > + > +4.2 PS2EMU_CMD_SET_PORT_TYPE > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + Sets the type of port we're emulating, where "data" is the port type being > +set. Can be any of the following macros from <linux/serio.h>: > + > + SERIO_8042 > + SERIO_8042_XL > + SERIO_PS_PSTHRU > + > +4.3 PS2EMU_CMD_SEND_INTERRUPT > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + Sends an interrupt through the virtual PS/2 port to the serio driver, where > +"data" is the interrupt data being sent. > + > +5. Userspace tools > +~~~~~~~~~~~~~~~~~~ > + The ps2emu userspace tools are able to record PS/2 devices using some of > the > +debugging information from i8042, and play back the devices on /dev/ps2emu. > The > +latest version of these tools can be found at: > + > + https://github.com/Lyude/ps2emu > diff --git a/MAINTAINERS b/MAINTAINERS > index a226416..68a0977 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -10877,6 +10877,12 @@ S: Maintained > F: drivers/media/v4l2-core/videobuf2-* > F: include/media/videobuf2-* > > +VIRTUAL PS/2 DEVICE DRIVER > +M: Stephen Chandler Paul <[email protected]> > +S: Maintained > +F: drivers/input/serio/ps2emu.c > +F: include/uapi/linux/ps2emu.h > + > VIRTIO CONSOLE DRIVER > M: Amit Shah <[email protected]> > L: [email protected] > diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig > index 200841b..cc3563f 100644 > --- a/drivers/input/serio/Kconfig > +++ b/drivers/input/serio/Kconfig > @@ -292,4 +292,14 @@ config SERIO_SUN4I_PS2 > To compile this driver as a module, choose M here: the > module will be called sun4i-ps2. > > +config PS2EMU > + tristate "Virtual PS/2 device support" > + help > + Say Y here if you want to emulate PS/2 devices using the ps2emu tools. > + > + To compile this driver as a module, choose M here: the module will be > + called ps2emu. > + > + If you are unsure, say N. > + > endif > diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile > index c600089..7b20936 100644 > --- a/drivers/input/serio/Makefile > +++ b/drivers/input/serio/Makefile > @@ -30,3 +30,4 @@ obj-$(CONFIG_SERIO_APBPS2) += apbps2.o > obj-$(CONFIG_SERIO_OLPC_APSP) += olpc_apsp.o > obj-$(CONFIG_HYPERV_KEYBOARD) += hyperv-keyboard.o > obj-$(CONFIG_SERIO_SUN4I_PS2) += sun4i-ps2.o > +obj-$(CONFIG_PS2EMU) += ps2emu.o > diff --git a/drivers/input/serio/ps2emu.c b/drivers/input/serio/ps2emu.c > new file mode 100644 > index 0000000..77b5ca8 > --- /dev/null > +++ b/drivers/input/serio/ps2emu.c > @@ -0,0 +1,253 @@ > +/* > + * ps2emu kernel PS/2 device emulation module > + * Copyright (C) 2015 Red Hat > + * Copyright (C) 2015 Stephen Chandler Paul <[email protected]> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU Lesser General Public License as published by > the > + * Free Software Foundation; either version 2 of the License, or (at your > + * option) any later version. > + * > + * This program is distributed in the hope that it will be useful, but > WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > FITNESS > + * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for > more > + * details. > + */ > +#include <linux/circ_buf.h> > +#include <linux/mutex.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/serio.h> > +#include <linux/libps2.h> > +#include <linux/slab.h> > +#include <linux/fs.h> > +#include <linux/miscdevice.h> > +#include <linux/sched.h> > +#include <linux/poll.h> > +#include <uapi/linux/ps2emu.h> > + > +#define PS2EMU_NAME "ps2emu" > +#define PS2EMU_MINOR MISC_DYNAMIC_MINOR
Don't redefine existing values like this, it makes it hard to review, just use MISC_DYNAMIC_MINOR. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
