net: ipa: pass a platform device to ipa_smp2p_init()

Rather than using the platform device pointer field in the IPA
pointer, pass a platform device pointer to ipa_smp2p_init(). Use
that pointer throughout that function.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipa: update copyrights

Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ipa: separate disabling setup from modem stop

The IPA setup_complete flag is set at the end of ipa_setup(), when
the setup phase of initialization has completed successfully. This
occurs as part of driver probe processing, or (if "modem-init" is
specified in the DTS file) it is triggered by the "ipa-setup-ready"
SMP2P interrupt generated by the modem.

In the latter case, it's possible for driver shutdown (or remove) to
begin while setup processing is underway, and this can't be allowed.
The problem is that the setup_complete flag is not adequate to signal
that setup is underway.

If setup_complete is set, it will never be un-set, so that case is
not a problem. But if setup_complete is false, there's a chance
setup is underway.

Because setup is triggered by an interrupt on a "modem-init" system,
there is a simple way to ensure the value of setup_complete is safe
to read. The threaded handler--if it is executing--will complete as
part of a request to disable the "ipa-modem-ready" interrupt. This
means that ipa_setup() (which is called from the handler) will run
to completion if it was underway, or will never be called otherwise.

The request to disable the "ipa-setup-ready" interrupt is currently
made within ipa_modem_stop(). Instead, disable the interrupt
outside that function in the two places it's called. In the case of
ipa_remove(), this ensures the setup_complete flag is safe to read
before we read it.

Rename ipa_smp2p_disable() to be ipa_smp2p_irq_disable_setup(), to be
more specific about its effect.

Fixes: 530f9216a953 ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipa: rename ipa_clock_* symbols

Rename a number of functions to clarify that there is no longer a
notion of an "IPA clock," but rather that the functions are more
generally related to IPA power management.

ipa_clock_enable() -> ipa_power_enable()
ipa_clock_disable() -> ipa_power_disable()
ipa_clock_rate() -> ipa_core_clock_rate()
ipa_clock_init() -> ipa_power_init()
ipa_clock_exit() -> ipa_power_exit()

Rename the ipa_clock structure to be ipa_power. Rename all
variables and fields using that structure type "power" rather
than "clock".

Rename the ipa_clock_data structure to be ipa_power_data, and more
broadly, just substitute "power" for "clock" in places that
previously represented things related to the "IPA clock".

Update comments throughout.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipa: fix all kernel-doc warnings

Fix all warnings produced when running:
scripts/kernel-doc -none drivers/net/ipa/*.[ch]

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipa: fix kerneldoc comments

This commit affects comments (and in one case, whitespace) only.

Throughout the IPA code, return statements are documented using
"@Return:", whereas they should use "Return:" instead. Fix these
mistakes.

In function definitions, some parameters are missing their comment
to describe them. And in structure definitions, some fields are
missing their comment to describe them. Add these missing
descriptions.

Some arguments changed name and type along the way, but their
descriptions were not updated (an endpoint pointer is now used in
many places that previously used an endpoint ID). Fix these
incorrect parameter descriptions.

In the description for the ipa_clock structure, one field had a
semicolon instead of a colon in its description. Fix this.

Add a missing function description for ipa_gsi_endpoint_data_empty().

All of these issues were identified when building with "W=1".

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

soc: qcom: ipa: AP/modem communications

This patch implements two forms of out-of-band communication between
the AP and modem.

- QMI is a mechanism that allows clients running on the AP
interact with services running on the modem (and vice-versa).
The AP IPA driver uses QMI to communicate with the corresponding
IPA driver resident on the modem, to agree on parameters used
with the IPA hardware and to ensure both sides are ready before
entering operational mode.

- SMP2P is a more primitive mechanism available for the modem and
AP to communicate with each other. It provides a means for either
the AP or modem to interrupt the other, and furthermore, to provide
32 bits worth of information. The IPA driver uses SMP2P to tell
the modem what the state of the IPA clock was in the event of a
crash. This allows the modem to safely access the IPA hardware
(or avoid doing so) when a crash occurs, for example, to access
information within the IPA hardware.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>