Platform drivers need make a lot of resource state requests at the same
time, say, at the start or end of an usecase. It can be quite
inefficient to send each request separately. Instead they can give the
RPMH library a batch of requests to be sent and wait on the whole
transaction to be complete.

rpmh_write_batch() is a blocking call that can be used to send multiple
RPMH command sets. Each RPMH command set is set asynchronously and the
API blocks until all the command sets are complete and receive their
tx_done callbacks.
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
Signed-off-by: NRaju P.L.S.S.S.N <rplsssn@codeaurora.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>

Platform drivers that want to send a request but do not want to block
until the RPMH request completes have now a new API -
rpmh_write_async().

The API allocates memory and send the requests and returns the control
back to the platform driver. The tx_done callback from the controller is
handled in the context of the controller's thread and frees the
allocated memory. This API allows RPMH requests from atomic contexts as
well.
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
Signed-off-by: NRaju P.L.S.S.S.N <rplsssn@codeaurora.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>

Active state requests are sent immediately to the RSC controller, while
sleep and wake state requests are cached in this driver to avoid taxing
the RSC controller repeatedly. The cached values will be sent to the
controller when the rpmh_flush() is called.

Generally, flushing is a system PM activity and may be called from the
system PM drivers when the system is entering suspend or deeper sleep
modes during cpuidle.

Also allow invalidating the cached requests, so they may be re-populated
again.
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
[rplsssn: remove unneeded semicolon, address line over 80chars error]
Signed-off-by: NRaju P.L.S.S.S.N <rplsssn@codeaurora.org>
Reviewed-by: NEvan Green <evgreen@chromium.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>

Sending RPMH requests and waiting for response from the controller
through a callback is common functionality across all platform drivers.
To simplify drivers, add a library functions to create RPMH client and
send resource state requests.

rpmh_write() is a synchronous blocking call that can be used to send
active state requests.
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
Signed-off-by: NRaju P.L.S.S.S.N <rplsssn@codeaurora.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>

Add controller driver for QCOM SoCs that have hardware based shared
resource management. The hardware IP known as RSC (Resource State
Coordinator) houses multiple Direct Resource Voter (DRV) for different
execution levels. A DRV is a unique voter on the state of a shared
resource. A Trigger Control Set (TCS) is a bunch of slots that can house
multiple resource state requests, that when triggered will issue those
requests through an internal bus to the Resource Power Manager Hardened
(RPMH) blocks. These hardware blocks are capable of adjusting clocks,
voltages, etc. The resource state request from a DRV are aggregated
along with state requests from other processors in the SoC and the
aggregate value is applied on the resource.

Some important aspects of the RPMH communication -
- Requests are <addr, value> with some header information
- Multiple requests (upto 16) may be sent through a TCS, at a time
- Requests in a TCS are sent in sequence
- Requests may be fire-n-forget or completion (response expected)
- Multiple TCS from the same DRV may be triggered simultaneously
- Cannot send a request if another request for the same addr is in
  progress from the same DRV
- When all the requests from a TCS are complete, an IRQ is raised
- The IRQ handler needs to clear the TCS before it is available for
  reuse
- TCS configuration is specific to a DRV
- Platform drivers may use DRV from different RSCs to make requests

Resource state requests made when CPUs are active are called 'active'
state requests. Requests made when all the CPUs are powered down (idle
state) are called 'sleep' state requests. They are matched by a
corresponding 'wake' state requests which puts the resources back in to
previously requested active state before resuming any CPU. TCSes are
dedicated for each type of requests. Active mode TCSes (AMC) are used to
send requests immediately to the resource, while control TCS are used to
provide specific information to the controller. Sleep and Wake TCS send
sleep and wake requests, after and before the system halt respectively.
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
Signed-off-by: NRaju P.L.S.S.S.N <rplsssn@codeaurora.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>

Command DB is a simple database in the shared memory of QCOM SoCs, that
provides information regarding shared resources. Some shared resources
in the SoC have properties that are probed dynamically at boot by the
remote processor. The information pertaining to the SoC and the platform
are made available in the shared memory. Drivers can query this
information using predefined strings.
Signed-off-by: NMahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: NLina Iyer <ilina@codeaurora.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Signed-off-by: NAndy Gross <andy.gross@linaro.org>