misc: ti-st: make st_recv() conforming to tty_ldisc_ops::receive_buf()

That is change data type to u8 and count to unsigned int. And propagate
to both hooks (st_kim_recv() and kim_int_recv()).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230810091510.13006-19-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ti_wilink_st.h: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333

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 version 2 as
published by the free software foundation 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 general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 136 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: misc: ti-st: Use int instead of fuzzy char for callback status

On mips and parisc:

drivers/bluetooth/btwilink.c: In function 'ti_st_open':
drivers/bluetooth/btwilink.c:174:21: warning: overflow in implicit constant conversion [-Woverflow]
hst->reg_status = -EINPROGRESS;

drivers/nfc/nfcwilink.c: In function 'nfcwilink_open':
drivers/nfc/nfcwilink.c:396:31: warning: overflow in implicit constant conversion [-Woverflow]
drv->st_register_cb_status = -EINPROGRESS;

There are actually two issues:
1. Whether "char" is signed or unsigned depends on the architecture.
As the completion callback data is used to pass a (negative) error
code, it should always be signed.
2. EINPROGRESS is 150 on mips, 245 on parisc.
Hence -EINPROGRESS doesn't fit in a signed 8-bit number.

Change the callback status from "char" to "int" to fix these.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ti-st: use worker instead of calling st_int_write in wake up

The wake up method is called with the port lock held. The st_int_write
method calls port->ops->write with tries to acquire the lock again,
causing CPU to wait infinitely. Right way to do is to write data to port
in worker thread.

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Jacob Siverskog <jacob@teenage.engineering>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "ti-st: add device tree support"

This reverts commit 46d0d33350e9b32642d745a8b46a954910196b4d.

This binding is horrible and never should have been merged. It is not
documented nor are there any in tree users, so reverting it will not
break anything we care about. Lets revert it before we do have users.

The problems with it are:

- It is not documented.

- The GPIO connection is described with a custom property and uses Linux
GPIO numbering.

- The UART connection is described using the Linux tty device name.

Cc: Gigi Joseph <gigi.joseph@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ti-st: clean up data types (fix harmless memory corruption)

The big issue here is:

of_property_read_u32(np, "flow_cntrl", (u32 *)&dt_pdata->flow_cntrl);

"->flow_cntrl" is a char so when we write a 32 bit number to it then it
corrupts past the end of the char. It's probably hard to notice because
the struct has padding so the code works on little endian systems. But
on a big endian system the code would fail and on a 64 bit, big endian
systems then "nshutdown_gpio" and "baud_rate" would be buggy as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ti-st: add device tree support

When using device tree, driver configuration data need to be read from
device node.
Add support for getting the platform data information from the device
tree information stored in the .dtb file in case it exists.

Signed-off-by: Eyal Reizer <eyalr@ti.com>
Signed-off-by: bvijay <bvijay@ti.com>
Diff rendering mode:inlineside by side

Signed-off-by: Gigi Joseph <gigi.joseph@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: st_kim: Increase size of dev_name buffer to incorporate termination

Calling strncpy with a maximum size argument of 32 bytes on destination
array kim_gdata->dev_name of size 32 bytes might leave the destination
string unterminated.

Cc: gregkh@linuxfoundation.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

misc: st_kim: Increase size of dev_name buffer to incorporate termination

Calling strncpy with a maximum size argument of 32 bytes on destination
array kim_gdata->dev_name of size 32 bytes might leave the destination
string unterminated.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/ti-st: remove sparse warnings

remove sparse warnings by assigning right storage specifiers to functions and
also clean-up the declarations in the include/linux/ti_wilink_st.h

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: OMAP: WiLink platform data for the PandaBoard

The "uim" deamon requires sysfs entries that are filled in using
this platform data.

Signed-off-by: Mircea Gherzan <mgherzan@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers:misc:ti-st: platform hooks for chip states

Certain platform specific or Host-WiLink Interface specific actions would be
required to be taken when the chip is being enabled and after the chip is
disabled such as configuration of the mux modes for the GPIO of host connected
to the nshutdown of the chip or relinquishing UART after the chip is disabled.

Similar actions can also be taken when the chip is in deep sleep or when the
chip is awake. Performance enhancements such as configuring the host to run
faster when chip is awake and slower when chip is asleep can also be made
here.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers:misc:ti-st: handle delayed tty receive

When certain technologies shutdown their interface without waiting for
the acknowledgement from the chip. The receive_buf from the TTY would be
invoked a while after the relevant technology is unregistered.

This patch introduces a new flag "is_registered" which maintains the
state of protocols BT, FM or GPS and thereby removes the need to clear
the protocol data from ST when protocols gets unregistered.

This fixes corner cases when HCI RESET is sent down from bluetooth stack
and the receive_buf is called from tty after 250ms before which
bluetooth would have unregistered from the system.
OR - when FM application decides to close down the device without
sending a power-off FM command resulting in some RDS data or interrupt
data coming in after the driver is unregistered.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers:misc: ti-st: remove multiple gpio handling

TI shared transport driver previously intended to expose rfkill
entries for each of the protocol gpio that the chip would have.
However now in case such gpios exist, which requires to be enabled
for a specific protocol, the responsibility lay on protocol driver.
This patch removes the request/free of multiple gpios, rfkill struct
references and also removes the chip_toggle function.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers:misc: ti-st: firmware download optimization

To fasten the process of firmware download, the chip allows
disabling of the command complete event generation from host.
In these cases, only few very essential commands would have
the command complete events and hence the wait associated with
them.

So now the driver would wait for a command complete event, only
when it comes across a wait event during firmware parsing.
This would also mean we need to skip not just the change baud
rate command but also the wait for it.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers:misc: ti-st: move from rfkill to sysfs

The communication between ST KIM and UIM was interfaced
over the /dev/rfkill device node.
Move the interface to a simpler less abusive sysfs entry
mechanism and document it in Documentation/ABI/testing/
under sysfs-platform-kim.

Shared transport driver would now read the UART details
originally received by bootloader or firmware as platform
data.
The data read will be shared over sysfs entries for the user-space
UIM or other n/w manager/plugins to be read, and assist the driver
by opening up the UART, setting the baud-rate and installing the
line discipline.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers:misc: ti-st: register with channel IDs

The architecture of shared transport had begun with individual
protocols like bluetooth, fm and gps telling the shared transport
what sort of protocol they are and then expecting the ST driver
to parse the incoming data from chip and forward data only
relevant to the protocol drivers.

This change would mean each protocol drivers would also send
information to ST driver as to how to intrepret their protocol
data coming out of the chip.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers: misc: ti-st: fix review comments

Based on comments from Jiri Slaby, drop the register
storage specifier, remove the unused code, cleanup
the const to non-const type casting.
Also make the line discipline ops structure static, since
its a singleton, unmodified structure which need not be
in heap.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: ti-st: mv ti_wilink_st header

Move the header to a standard linux device driver location.
This should pave the way for other drivers to be moved into the relevant
directories.

ti_wilink_st.h is a common header file used by the TI's shared transport device
driver for WiLink chipsets. Each individual protocol drivers like bluetooth
driver, FM V4L2 driver and GPS drivers will make use of this header.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>