i2c: robotfuzz-osif: fix control-request directions

The direction of the pipe argument must match the request-type direction
bit or control requests may fail depending on the host-controller-driver
implementation.

Control transfers without a data stage are treated as OUT requests by
the USB stack and should be using usb_sndctrlpipe(). Failing to do so
will now trigger a warning.

Fix the OSIFI2C_SET_BIT_RATE and OSIFI2C_STOP requests which erroneously
used the osif_usb_read() helper and set the IN direction bit.

Reported-by: syzbot+9d7dadd15b8819d73f41@syzkaller.appspotmail.com
Fixes: 83e53a8f120f ("i2c: Add bus driver for for OSIF USB i2c device.")
Cc: stable@vger.kernel.org # 3.14
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372

Based on 1 normalized pattern(s):

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 version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: robotfuzz-osif: drop pointless test

In the for-loop test, ret will be either 0 or 1. So, the
comparison is pointless. Drop it, and drop the initializer
which is then also pointless.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: robotfuzz-osif: remove pointless local variable

Just use the value directly instead of assigning it to a
variable first. And then drop the unused variable.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: busses: constify i2c_algorithm structures

Declare i2c_algorithm structures as const as they are only stored in the
algo field of an i2c_adapter structure. This field is of type const, so
i2c_algorithm structures having this property can be made const too.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> for
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: robotfuzz-osif: Constify osif_table

osif_table is never modified, so declare it as const.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i2c: Add bus driver for for OSIF USB i2c device.

OSIF, Open Source InterFace, is a USB based i2c bus master. The
origional design was based on i2c-tiny-usb, but more modern versions
of the firmware running on the MegaAVR microcontroller use a different
protocol over the USB. This code is based on Barry Carter
<barry.carter@gmail.com> driver.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>