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  1. 16 Aug, 2019 1 commit
  3. 15 Aug, 2019 11 commits
  5. 14 Aug, 2019 7 commits
  7. 13 Aug, 2019 1 commit
  9. 12 Aug, 2019 20 commits
    • Sudeep Holla's avatar
      reset: Add support for resets provided by SCMI · c8ae9c2d
      Sudeep Holla authored 
      On some ARM based systems, a separate Cortex-M based System Control
Processor(SCP) provides the overall power, clock, reset and system
control. System Control and Management Interface(SCMI) Message Protocol
is defined for the communication between the Application Cores(AP)
and the SCP.

Adds support for the resets provided using SCMI protocol for performing
reset management of various devices present on the SoC. Various reset
functionalities are achieved by the means of different ARM SCMI device
operations provided by the ARM SCMI framework.
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      c8ae9c2d
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add RESET protocol in SCMI v2.0 · 95a15d80
      Sudeep Holla authored 
      SCMIv2.0 adds a new Reset Management Protocol to manage various reset
states a given device or domain can enter. Device(s) that can be
collectively reset through a common reset signal constitute a reset
domain for the firmware.

A reset domain can be reset autonomously or explicitly through assertion
and de-assertion of the signal. When autonomous reset is chosen, the
firmware is responsible for taking the necessary steps to reset the
domain and to subsequently bring it out of reset. When explicit reset is
chosen, the caller has to specifically assert and then de-assert the
reset signal by issuing two separate RESET commands.

Add the basic SCMI reset infrastructure that can be used by Linux
reset controller driver.
Reviewed-by: default avatarPeng Fan <peng.fan@nxp.com>
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      95a15d80
    • Sudeep Holla's avatar
      dt-bindings: arm: Extend SCMI to support new reset protocol · ae39913c
      Sudeep Holla authored 
      SCMIv2.0 adds a new Reset Management Protocol to manage various reset
states a given device or domain can enter. Extend the existing SCMI
bindings to add reset protocol support by re-using the reset bindings
for both reset providers and consumers.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      ae39913c
    • Sudeep Holla's avatar
      firmware: arm_scmi: Make use SCMI v2.0 fastchannel for performance protocol · 82383957
      Sudeep Holla authored 
      SCMI v2.0 adds support for "FastChannel" which do not use a message
header as they are specialized for a single message.

Only PERFORMANCE_LIMITS_{SET,GET} and PERFORMANCE_LEVEL_{SET,GET}
commands are supported over fastchannels. As they are optional, they
need to be discovered by PERFORMANCE_DESCRIBE_FASTCHANNEL command.
Further {LIMIT,LEVEL}_SET commands can have optional doorbell support.

Add support for making use of these fastchannels.

Cc: Ionela Voinescu <Ionela.Voinescu@arm.com>
Cc: Chris Redpath <Chris.Redpath@arm.com>
Cc: Quentin Perret <Quentin.Perret@arm.com>
Reviewed-by: default avatarPeng Fan <peng.fan@nxp.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      82383957
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add discovery of SCMI v2.0 performance fastchannels · ac8aaf34
      Sudeep Holla authored 
      SCMI v2.0 adds support for "FastChannel", a lightweight unidirectional
channel that is dedicated to a single SCMI message type for controlling
a specific platform resource. They do not use a message header as they
are specialized for a single message.

Only PERFORMANCE_LIMITS_{SET,GET} and PERFORMANCE_LEVEL_{SET,GET}
commands are supported over fastchannels. As they are optional, they
need to be discovered by PERFORMANCE_DESCRIBE_FASTCHANNEL command.
Further {LIMIT,LEVEL}_SET commands can have optional doorbell support.

Add support for discovery of these fastchannels.

Cc: Ionela Voinescu <Ionela.Voinescu@arm.com>
Cc: Chris Redpath <Chris.Redpath@arm.com>
Cc: Quentin Perret <Quentin.Perret@arm.com>
Reviewed-by: default avatarPeng Fan <peng.fan@nxp.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      ac8aaf34
    • Sudeep Holla's avatar
      firmware: arm_scmi: Use {get,put}_unaligned_le{32,64} accessors · aa90ac45
      Sudeep Holla authored 
      Instead of type-casting the {tx,rx}.buf all over the place while
accessing them to read/write __le{32,64} from/to the firmware, let's
use the existing {get,put}_unaligned_le{32,64} accessors to hide all
the type cast ugliness.
Suggested-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      aa90ac45
    • Sudeep Holla's avatar
      firmware: arm_scmi: Use asynchronous CLOCK_RATE_SET when possible · 2bc06ffa
      Sudeep Holla authored 
      CLOCK_PROTOCOL_ATTRIBUTES provides attributes to indicate the maximum
number of pending asynchronous clock rate changes supported by the
platform. If it's non-zero, then we should be able to use asynchronous
clock rate set for any clocks until the maximum limit is reached.

Tracking the current count of pending asynchronous clock set rate
requests, we can decide if the incoming/new request for clock set rate
can be handled asynchronously or not until the maximum limit is
reached.

Cc: linux-clk@vger.kernel.org
Reviewed-by: default avatarStephen Boyd <sboyd@kernel.org>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      2bc06ffa
    • Sudeep Holla's avatar
      firmware: arm_scmi: Drop config flag in clk_ops->rate_set · d0aba116
      Sudeep Holla authored 
      CLOCK_PROTOCOL_ATTRIBUTES provides attributes to indicate the maximum
number of pending asynchronous clock rate changes supported by the
platform. If it's non-zero, then we should be able to use asynchronous
clock rate set for any clocks until the maximum limit is reached.

In order to add that support, let's drop the config flag passed to
clk_ops->rate_set and handle the asynchronous requests dynamically.

Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Acked-by: default avatarStephen Boyd <sboyd@kernel.org>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      d0aba116
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add asynchronous sensor read if it supports · d09aac0e
      Sudeep Holla authored 
      SENSOR_DESCRIPTION_GET provides attributes to indicate if the sensor
supports asynchronous read. We can read that flag and use asynchronous
reads for any sensors with that attribute set.

Let's use the new scmi_do_xfer_with_response to support asynchronous
sensor reads.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      d09aac0e
    • Sudeep Holla's avatar
      firmware: arm_scmi: Drop async flag in sensor_ops->reading_get · 6a55331c
      Sudeep Holla authored 
      SENSOR_DESCRIPTION_GET provides attributes to indicate if the sensor
supports asynchronous read. Ideally we should be able to read that flag
and use asynchronous reads for any sensors with that attribute set.

In order to add that support, let's drop the async flag passed to
sensor_ops->reading_get and dynamically switch between sync and async
flags based on the attributes as provided by the firmware.

Cc: linux-hwmon@vger.kernel.org
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      6a55331c
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add support for asynchronous commands and delayed response · 58ecdf03
      Sudeep Holla authored 
      Messages that are sent to platform, also known as commands and can be:

1. Synchronous commands that block the channel until the requested work
has been completed. The platform responds to these commands over the
same channel and hence can't be used to send another command until the
previous command has completed.

2. Asynchronous commands on the other hand, the platform schedules the
requested work to complete later in time and returns almost immediately
freeing the channel for new commands. The response indicates the success
or failure in the ability to schedule the requested work. When the work
has completed, the platform sends an additional delayed response message.

Using the same transmit buffer used for sending the asynchronous command
even for the delayed response corresponding to it simplifies handling of
the delayed response. It's the caller of asynchronous command that is
responsible for allocating the completion flag that scmi driver can
complete to indicate the arrival of delayed response.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      58ecdf03
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add mechanism to unpack message headers · 22d1f761
      Sudeep Holla authored 
      In order to identify the message type when a response arrives, we need
a mechanism to unpack the message header similar to packing. Let's
add one.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      22d1f761
    • Sudeep Holla's avatar
      firmware: arm_scmi: Separate out tx buffer handling and prepare to add rx · 38c927fb
      Sudeep Holla authored 
      Currently we pre-allocate transmit buffers only and use the first free
slot in that pre-allocated buffer for transmitting any new message that
are generally originated from OS to the platform firmware.

Notifications or the delayed responses on the other hand are originated
from the platform firmware and consumes by the OS. It's better to have
separate and dedicated pre-allocated buffers to handle the notifications.
We can still use the transmit buffers for the delayed responses.

In addition, let's prepare existing scmi_xfer_{get,put} for acquiring
and releasing a slot to identify the right(tx/rx) buffers.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      38c927fb
    • Sudeep Holla's avatar
      firmware: arm_scmi: Add receive channel support for notifications · 46cc7c28
      Sudeep Holla authored 
      With scmi_mbox_chan_setup enabled to identify and setup both Tx and Rx,
let's consolidate setting up of both the channels under the function
scmi_mbox_txrx_setup.

Since some platforms may opt not to support notifications or delayed
response, they may not need support for Rx. Hence Rx is optional and
failure of setting one up is not considered fatal.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      46cc7c28
    • Sudeep Holla's avatar
      firmware: arm_scmi: Segregate tx channel handling and prepare to add rx · 3748daf7
      Sudeep Holla authored 
      The transmit(Tx) channels are specified as the first entry and the
receive(Rx) channels are the second entry as per the device tree
bindings. Since we currently just support Tx, index 0 is hardcoded at
all required callsites.

In order to prepare for adding Rx support, let's remove those hardcoded
index and add boolean parameter to identify Tx/Rx channels when setting
them up.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      3748daf7
    • Sudeep Holla's avatar
      firmware: arm_scmi: Reorder some functions to avoid forward declarations · 2747a967
      Sudeep Holla authored 
      Re-shuffling few functions to keep definitions and their usages close.
This is also needed to avoid too many unnecessary forward declarations
while adding new features(delayed response and notifications).

Keeping this separate to avoid mixing up of these trivial change that
doesn't affect functionality into the ones that does.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      2747a967
    • Sudeep Holla's avatar
      firmware: arm_scmi: Check if platform has released shmem before using · 9dc34d63
      Sudeep Holla authored 
      Sometimes platfom may take too long to respond to the command and OS
might timeout before platform transfer the ownership of the shared
memory region to the OS with the response.

Since the mailbox channel associated with the channel is freed and new
commands are dispatch on the same channel, OS needs to wait until it
gets back the ownership. If not, either OS may end up overwriting the
platform response for the last command(which is fine as OS timed out
that command) or platform might overwrite the payload for the next
command with the response for the old.

The latter is problematic as platform may end up interpretting the
response as the payload. In order to avoid such race, let's wait until
the OS gets back the ownership before we prepare the shared memory with
the payload for the next command.
Reported-by: default avatarJim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      9dc34d63
    • Sudeep Holla's avatar
      firmware: arm_scmi: Use the term 'message' instead of 'command' · 5b65af8f
      Sudeep Holla authored 
      In preparation to adding support for other two types of messages that
SCMI specification mentions, let's replace the term 'command' with the
correct term 'message'.

As per the specification the messages are of 3 types:
commands(synchronous or asynchronous), delayed responses and notifications.
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      5b65af8f
    • Sudeep Holla's avatar
      firmware: arm_scmi: Fix few trivial typos in comments · c29a6289
      Sudeep Holla authored 
      While adding new comments found couple of typos that are better fixed.

s/informfation/information/
s/statues/status/
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      c29a6289
    • Sudeep Holla's avatar
      firmware: arm_scmi: Remove extra check for invalid length message responses · 37bbffcb
      Sudeep Holla authored 
      scmi_xfer_get_init ensures both transmit and receive buffer lengths are
within the maximum limits. If receive buffer length is not supplied by
the caller, it's set to the maximum limit value. Receive buffer length
is never modified after that. So there's no need for the extra check
when receive transmit completion for a command essage.

Further, if the response header length is greater than the prescribed
receive buffer length, the response buffer is truncated to the latter.
Reported-by: default avatarJim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
      37bbffcb
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