Clock request disabled when PMU enabled

Currently clock request is enabled, which means NPU will
only request clock when working. When NPU is going into idle it will no
longer request clock and thus PMU won't be clocked either, and thus
affect the cycle counter.

Added: enum for request clients (PMU or INFERENCE).

Added: clock_request added to driver struct (bit 0: PMU, bit 1:
INFERENCE) which keeps track of which client requests clock.

Added: power_request added to driver struct (bit 0: PMU, bit 1:
INFERENCE) which keeps track of which client requests power.

Added set_clock_and_power_request(...) updates clock_request and
power_request depending on which client calls it. Sets clock and power
if both PMU and INFERENCE requests it.

Added: Call set_clock_and_power_request(...) from PMU.

Changed: replace ethosu_set_clock_and_power(...) with
set_clock_and_power_request(...) in ethosu_init and ethosu_invoke

Change-Id: Ie7d8aee639d4abbf879b05e9a82035d7c0d40d40
3 files changed
tree: 19a72b883f5c765528d853bb515fecb514c75d50
  1. .clang-format
  2. CMakeLists.txt
  3. LICENSE.txt
  4. README.md
  5. SECURITY.md
  6. include/
  7. src/
README.md

Arm(R) Ethos(TM)-U core driver

This repository contains a device driver for the Arm(R) Ethos(TM)-U NPU.

Building

The source code comes with a CMake based build system. The driver is expeced to be cross compiled for any of the supported Arm Cortex(R)-M CPUs, which will require the user to setup a custom toolchain file.

The user is also required to define CMAKE_SYSTEM_PROCESSOR for the target CPU, for example cortex-m55+nodsp+nofp. This can be done either in the toolchain file or on the command line.

$ mkdir build
$ cd build
$ cmake .. -DCMAKE_TOOLCHAIN_FILE=<toolchain> -DCMAKE_SYSTEM_PROCESSOR=cortex-m<nr><features>
$ make

For running the driver on Arm CPUs which are configured with datacache, the cache maintenance functions in the driver are exported with weakly linked symbols that should be overriden. An example implementation using the CMSIS primitives found in cachel1_armv7.h could be as below:

extern "C" {
void ethosu_flush_dcache(uint32_t *p, size_t bytes) {
    if (p)
        SCB_CleanDCache_by_Addr(p, bytes);
    else
        SCB_CleanDCache();
}

void ethosu_invalidate_dcache(uint32_t *p, size_t bytes) {
    if (p)
        SCB_InvalidateDCache_by_Addr(p, bytes);
    else
        SCB_InvalidateDCache();
}
}

License

The Arm Ethos-U core driver is provided under an Apache-2.0 license. Please see LICENSE.txt for more information.

Contributions

The Arm Ethos-U project welcomes contributions under the Apache-2.0 license.

Before we can accept your contribution, you need to certify its origin and give us your permission. For this process we use the Developer Certificate of Origin (DCO) V1.1 (https://developercertificate.org).

To indicate that you agree to the terms of the DCO, you "sign off" your contribution by adding a line with your name and e-mail address to every git commit message. You must use your real name, no pseudonyms or anonymous contributions are accepted. If there are more than one contributor, everyone adds their name and e-mail to the commit message.

Author: John Doe \<john.doe@example.org\>
Date:   Mon Feb 29 12:12:12 2016 +0000

Title of the commit

Short description of the change.
   
Signed-off-by: John Doe john.doe@example.org
Signed-off-by: Foo Bar foo.bar@example.org

The contributions will be code reviewed by Arm before they can be accepted into the repository.

Security

Please see Security.

Trademark notice

Arm, Cortex and Ethos are registered trademarks of Arm Limited (or its subsidiaries) in the US and/or elsewhere.