rpmsg: glink: Fix spelling of peek

The code is peeking into the buffers, not peaking. Fix this throughout
the glink drivers.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230214224746.1996130-1-quic_bjorande@quicinc.com

rpmsg: glink: Move irq and mbox handling to transports

Not all GLINK transports uses an interrupt and a mailbox instance. The
interrupt for RPM needs to be IRQF_NOSUSPEND, while it seems reasonable
for the SMEM interrupt to use irq_set_wake. The glink struct device is
constructed in the SMEM and RPM drivers but torn down in the core
driver.

Move the interrupt and kick handling into the SMEM and RPM driver, to
improve this and facilitate further improvements.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-5-quic_bjorande@quicinc.com

rpmsg: glink: Include types in qcom_glink_native.h

Ensure that the used data types are available in qcom_glink_native.h, to
silence LSP warnings.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109223745.1706152-1-quic_bjorande@quicinc.com

rpmsg: glink: Switch to SPDX license identifier

Use the appropriate SPDX license identifier in various rpmsg
glink driver source files and drop the previous boilerplate
license text.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Make RX FIFO peak accessor to take an offset

To fully read the received rx data from FIFO both the command and data
has to be read. Currently we read command, data separately and process
them. By adding an offset parameter to RX FIFO peak accessor, command
and data can be read together, simplifying things. So introduce this.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support for TX intents

Intents are nothing but pre-allocated buffers of appropriate size that
are allocated on the local side and communicated to the remote side and
the remote stores the list of intent ids that it is informed.

Later when remote side is intenting to send data, it picks up a right
intent (based on the size) and sends the data buffer and the intent id.
Local side receives the data and copies it to the local intent buffer.

The whole idea is to avoid stalls on the transport for allocating
memory, used for copy based transports.

When the remote request to allocate buffers using CMD_RX_INTENT_REQ, we
allocate buffers of requested size, store the buffer id locally and also
communicate the intent id to the remote.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support for transport version negotiation

G-link supports a version number and feature flags for each transport.
A combination of the version number and feature flags enable/disable:

(*) G-Link software updates for each edge
(*) Individual features for each edge

Endpoints negotiate both the version and the supported flags when
the transport is opened and they cannot be changed after negotiation has
been completed.

Each full implementation of G-Link must support a minimum of the current
version, the previous version, and the base negotiation version called v0.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Introduce glink smem based transport

The glink protocol supports different types of transports (shared
memory). With the core protocol remaining the same, the way the
transport's memory is probed and accessed is different. So add support
for glink's smem based transports.

Adding a new smem transport register function and the fifo accessors for
the same.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Move the common glink protocol implementation to glink_native.c

Move the common part of glink core protocol implementation to
glink_native.c that can be shared with the smem based glink
transport in the later patches.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>