The function visorutil_spar_detect had an if clause that returns from the
function, no need to do the rest of the code in an else clause.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The data field was being defined as a character array and then casted into
a visor_controlvm_parameters_header structure. This patch converts it to
just point to the visor_controlvm_parameters_header structure. The data
following the header is still behind the header_info.
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Visorbus_configure had a block of "else if" clauses at the beginning of the
function. Simplify this to just being "if" clauses since each code block
ended with a goto.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable parm_addr will never be null, so no need to check for it.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable ctx was allocated with kzalloc, so all the data inside is
zero, no need to reset it to 0.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently setting it in the right location, so no longer not sure.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The functions to create the controlvm channel were disjointed and ignoring
information that was available. This patch consolidates it so it clearer
what is happening.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Checkpatch reports an error that no comment was next to the mutex lock.
Add an appropriate message for the lock.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The macro to convert to the driver object was giving a checkpatch warning
when it ateempted to check for a null driver. It would return NULL if it
found it, but only one location was checking to see if it was NULL.

Remove the check in the MACRO and do it prior to calling the macro if
required.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The dev_err was using the hardcoded function name, as reported by
checkpatch, it should be using __func__.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Several macros in visorchannel.c were doing complex arithmetic, converted
them to functions so that valid type checking could be done.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed the following checkpatch warning:
visorchannel.c:443: CHECK: Alignment should match open parenthesis
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function vmcall address needed to be cleaned up. The structure
vmcall_controlvm_addr was not needed so it was removed and was replaced
with vmcall_io_controlvm_addr_params since it needs to be allocated on the
heap for DMA access.

With the structure removed and the fields as local variables, it helped
clean up the formatting of the function.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes miscellaneous formatting issues with several block comments
throughout visornic_main.c.
Signed-off-by: David Binder <david.binder@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Refactors existing static function comments to increase code readability.
Signed-off-by: David Binder <david.binder@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: unisys: visorbus: visorbus_main.c: Fix return values for checks in visorbus_register_visor_driver.

The error return values for the drv->probe, drv->remove, drv->pause
and drv->resume checks should be -EINVAL instead of -ENODEV.
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sameer Wadgaonkar <sameer.wadgaonkar@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes a bug in the function parser_init_byte_stream()
by removing the call to parser_done from goto err_finish_ctx.
The function parser_done() decrements
chipset_dev->controlvm_payload_bytes_buffered which is not
incremented before this gets called.
Signed-off-by: Sameer Wadgaonkar <sameer.wadgaonkar@unisys.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The kernel already provides a min function, we should be using that
instead of creating our own MINNUM.
Reviewed-by: Sameer Wadgaonkar <sameer.wadgaonkar@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Removed printk statements for debugging. The same information can be
acquired via ftrace, so these print statements are uneccessary.
Signed-off-by: Jonathan Whitaker <jon.b.whitaker@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch removes "WARNING: Prefer using '"%s...", __func__'
to using 'xxxxxxxx', this function's name, in a string" warnings
reported by checkpatch.pl script.
Signed-off-by: Simo Koskinen <koskisoft@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit fixes alignment styling as reported by checkpatch.pl.
Signed-off-by: Jonathan Whitaker <jon.b.whitaker@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

casting to void pointer from any pointer type and vice-versa is done
implicitly and therefore casting is not needed in such a case.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

casting to void pointer from any pointer type and vice-versa is done
implicitly and therefore casting is not needed in such a case.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

casting to void pointer from any pointer type and vice-versa is done
implicitly and therefore casting is not needed in such a case.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

call to memset to assign 0 value immediately after allocating
memory with kzalloc is unnecesaary as kzalloc allocates the memory
filled with 0 value.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

calling memcpy immediately after memset with the same region of memory
makes memset redundant.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When VBUS is not discovered within PD_T_PS_SOURCE_ON although Rp
is detected on CC, TCPM switches the port to SNK_UNATTACHED
state. SNK_UNATTACHED, however does not force TYPEC_CC_OPEN which
makes the partner(source) to think that it is connected.

To overcome this issue, force the port into PORT_RESET state
to make sure the CC lines are open.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PING messages are used to monitor the connect/disconnect.
However, when PD is carried over CC, so this is not required.

Also, the spec does not clearly say if PD is possible when
Type-c is connected to Type-A/B. So, removing sending
PING messages altogether.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Once, Rp or Rd is switched, wait for PD_T_CC_DEBOUNCE. If not the
PS_RDY message transmitted might result in failure.
Also, Only wait for PD_T_SRCSWAPSTDBY while in
PR_SWAP_SRC_SNK_TRANSITION_OFF. PD_T_PS_SOURCE_OFF is the overall
time after which the initial sink would issue hard reset.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the case that the lower layer driver reports a cc change directly
from SINK state to SOURCE state, TCPM doesn't handle these cc change
in SRC_SEND_CAPABILITIES, SRC_READY states. And with SRC_ATTACHED
state, the change is not handled as the port is still considered
connected.

[49606.131672] state change DRP_TOGGLING -> SRC_ATTACH_WAIT
[49606.131701] pending state change SRC_ATTACH_WAIT -> SRC_ATTACHED @
200 ms
[49606.329952] state change SRC_ATTACH_WAIT -> SRC_ATTACHED [delayed 200
ms]
[49606.329978] polarity 0
[49606.329989] Requesting mux mode 1, config 0, polarity 0
[49606.349416] vbus:=1 charge=0
[49606.372274] pending state change SRC_ATTACHED -> SRC_UNATTACHED @ 480
ms
[49606.372431] VBUS on
[49606.372488] state change SRC_ATTACHED -> SRC_STARTUP
...
(the lower layer driver reports a direct change from source to sink)
[49606.536927] pending state change SRC_SEND_CAPABILITIES ->
SRC_SEND_CAPABILITIES @ 150 ms
[49606.547244] CC1: 2 -> 5, CC2: 0 -> 0 [state SRC_SEND_CAPABILITIES,
polarity 0, connected]

This can happen when the lower layer driver and/or the hardware
handles a portion of the Type-C state machine work, and quietly goes
through the unattached state.

Originally-from: Yueyao Zhu <yueyao@google.com>
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

While performing PORT_RESET, upon receiving the cc disconnect
signal from the underlaying tcpc device, TCPM transitions into
unattached state. Consider the current type of port while determining
the unattached state.

In the below logs, although the port_type was set to sink, TCPM
transitioned into SRC_UNATTACHED.

[  762.290654] state change SRC_READY -> PORT_RESET
[  762.324531] Setting voltage/current limit 0 mV 0 mA
[  762.327912] polarity 0
[  762.334864] cc:=0
[  762.347193] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms
[  762.347200] VBUS off
[  762.347203] CC1: 2 -> 0, CC2: 0 -> 0 [state PORT_RESET, polarity 0, disconnected]
[  762.347206] state change PORT_RESET -> SRC_UNATTACHED
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the spec:
"4.5.2.2.10.2 Exiting from TryWait.SNK State
The port shall transition to Attached.SNK after tCCDebounce if or when VBUS
is detected. Note the Source may initiate USB PD communications which will
cause brief periods of the SNK.Open state on both the CC1 and CC2 pins,
but this event will not exceed tPDDebounce. The port shall transition to
Unattached.SNK when the state of both of the CC1 and CC2 pins is SNK.Open
for at least tPDDebounce."
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to spec:
" 4.5.2.2.9.2 Exiting from Try.SRC State:
The port shall transition to Attached.SRC when the SRC.Rd
state is detected on exactly one of the CC1 or CC2 pins for
at least tPDDebounce. The port shall transition to
TryWait.SNK after tDRPTry and the SRC.Rd state has not been
detected."
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According the spec, the following is the conditions for exiting Try.SNK
state:
"The port shall wait for tDRPTry and only then begin monitoring the CC1 and
CC2 pins for the SNK.Rp state. The port shall then transition to
Attached.SNK when the SNK.Rp state is detected on exactly one of the CC1
or CC2 pins for at least tPDDebounce and V BUS is detected. Alternatively,
the port shall transition to TryWait.SRC if SNK.Rp state is not detected
for tPDDebounce."
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the spec the following is the condition
for exiting TryWait.SRC:

"The port shall transition to Attached.SRC when V BUS is at vSafe0V
and the SRC.Rd state is detected on exactly one of the CC pins for at
least tCCDebounce. The port shall transition to Unattached.SNK after
tDRPTry if neither of the CC1 or CC2 pins are in the SRC.Rd state"

TCPM at present keeps re-entering the SRC_TRYWAIT and keeps restarting
tDRPTry if the CC presents Rp and disconnects within tCCDebounce.

For example:
[  447.164308] pending state change SRC_TRYWAIT -> SRC_ATTACHED @ 200 ms
[  447.164386] CC1: 2 -> 0, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, disconnected]
[  447.164406] state change SRC_TRYWAIT -> SRC_TRYWAIT
[  447.164573] cc:=3
[  447.191408] pending state change SRC_TRYWAIT -> SRC_TRYWAIT_UNATTACHED @ 100 ms
[  447.191478] CC1: 0 -> 0, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, disconnected]
[  447.207261] CC1: 0 -> 2, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, connected]
[  447.207306] state change SRC_TRYWAIT -> SRC_TRYWAIT
[  447.207485] cc:=3
[  447.237283] pending state change SRC_TRYWAIT -> SRC_ATTACHED @ 200 ms
[  447.237357] CC1: 2 -> 0, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, disconnected]
[  447.237379] state change SRC_TRYWAIT -> SRC_TRYWAIT
[  447.237532] cc:=3
[  447.263219] pending state change SRC_TRYWAIT -> SRC_TRYWAIT_UNATTACHED @ 100 ms
[  447.263289] CC1: 0 -> 0, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, disconnected]
[  447.280926] CC1: 0 -> 2, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, connected]
[  447.280970] state change SRC_TRYWAIT -> SRC_TRYWAIT
[  447.281158] cc:=3
[  447.307767] pending state change SRC_TRYWAIT -> SRC_ATTACHED @ 200 ms
[  447.307838] CC1: 2 -> 0, CC2: 0 -> 0 [state SRC_TRYWAIT, polarity 0, disconnected]
[  447.307858] state change SRC_TRYWAIT -> SRC_TRYWAIT

In TCPM, tDRPTry is set tp 100ms (min 75ms and max 150ms)
and tCCdebounce is set to 200ms (min 100ms and max 200ms).
To overcome the issue, record the time at which the port
enters TryWait.SRC(SRC_TRYWAIT) and re-enter SRC_TRYWAIT
only when CC keeps debouncing within tDRPTry.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable Try.SRC or Try.SNK only when port_type is
DRP. Try.SRC or Try.SNK state machines are not
valid for SRC only or SNK only ports.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The port type callback call enquires the tcpc_dev if
the requested port type is supported. If supported, then
performs a tcpm reset if required after setting the tcpm
internal port_type variable.

Check against the tcpm port_type instead of checking
against caps.type as port_type reflects the current
configuration.
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since we have tty_kopen, we no longer need to export tty_open_by_driver.
This patch makes this function static.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch replaces call to tty_open_by_driver with a tty_kopen and
uses tty_kclose instead of tty_release_struct to close it.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit 12e84c71 ("tty: export tty_open_by_driver") exports
tty_open_by_device to allow tty to be opened from inside kernel which
works fine except that it doesn't handle contention with user space or
another kernel-space open of the same tty. For example, opening a tty
from user space while it is kernel opened results in failure and a
kernel log message about mismatch between tty->count and tty's file
open count.

This patch makes kernel access to tty exclusive, so that if a user
process or kernel opens a kernel opened tty, it gets -EBUSY. It does
this by adding TTY_KOPENED flag to tty->flags. When this flag is set,
tty_open_by_driver returns -EBUSY. Instead of overloading
tty_open_by_driver for both kernel and user space, this
patch creates a separate function tty_kopen which closely follows
tty_open_by_driver. tty_kclose closes the tty opened by tty_kopen.

To address the mismatch between tty->count and #fd's, this patch adds
#kopen's to the count before comparing it with tty->count. That way
check_tty_count reflects correct usage count.

Returning -EBUSY on tty open is a change in the interface. I have
tested this with minicom, picocom and commands like "echo foo >
/dev/ttyS0". They all correctly report "Device or resource busy" when
the tty is already kernel opened.
Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>