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scmi: Kernel instructions and changes for IIO added
Followup patches will allow connecting vhost-user-scmi to industrial I/O devices. On host without IIO devices, it’s possible to use emulated devices for testing. This patch documents how to use them and also provides a slightly customized IIO dummy kernel module. Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
This commit is contained in:
Milan Zamazal
Alex Bennée
parent
e0fdfa4c38
commit
4014a6366f
@ -65,9 +65,17 @@ The currently supported SCMI protocols are:
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Basically only the mandatory and necessary parts of the protocols are
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implemented.
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## Kernel support for testing
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`kernel` subdirectory contains
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[instructions](kernel/iio-dummy/README.md) how to create emulated
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industrial I/O devices for testing.
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## License
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This project is licensed under either of
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- [Apache License](http://www.apache.org/licenses/LICENSE-2.0), Version 2.0
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- [BSD-3-Clause License](https://opensource.org/licenses/BSD-3-Clause)
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unless specified in particular files otherwise.
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7
crates/scmi/kernel/iio-dummy/.gitignore
vendored
Normal file
7
crates/scmi/kernel/iio-dummy/.gitignore
vendored
Normal file
@ -0,0 +1,7 @@
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*.cmd
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*.ko
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*.mod
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*.mod.[co]
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*.o
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Module.symvers
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modules.order
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19
crates/scmi/kernel/iio-dummy/Makefile
Normal file
19
crates/scmi/kernel/iio-dummy/Makefile
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@ -0,0 +1,19 @@
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# SPDX-License-Identifier: GPL-2.0
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#
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# Makefile for the IIO Dummy Driver
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#
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# Modified by Milan Zamazal <mzamazal@redhat.com> in 2023 for out of
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# tree compilation.
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#
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obj-m += iio_modified_dummy.o
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on_nixos = $(wildcard /etc/NIXOS)
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ifeq ($(on_nixos), /etc/NIXOS)
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nix_prefix = $(shell nix-build -E '(import <nixpkgs> {}).linux.dev' --no-out-link)
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endif
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all:
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make -C $(nix_prefix)/lib/modules/$(shell uname -r)/build M=$(PWD) modules
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clean:
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make -C $(nix_prefix)/lib/modules/$(shell uname -r)/build M=$(PWD) clean
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184
crates/scmi/kernel/iio-dummy/README.md
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184
crates/scmi/kernel/iio-dummy/README.md
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@ -0,0 +1,184 @@
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# Using emulated industrial I/O devices
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This is a modified version of the Linux [industrial I/O dummy
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driver](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/iio/dummy).
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Both the original driver and this modification can provide emulated
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industrial I/O devices for testing vhost-device-scmi.
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## Modifications in this module
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If the stock industrial I/O dummy driver is enough for you, use it
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(but you may still want to read the instructions below).
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Otherwise, this alternative is provided with the following changes:
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- Simplified Makefile for out of tree compilation.
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- The accelerometer has three axes instead of just one.
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Of course, you can modified it further for your liking if needed.
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## How to create emulated industrial I/O devices
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Make sure your kernel supports software industrial I/O devices and
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industrial I/O with configfs. You can check this by running `modprobe
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industrialio_sw_device && modprobe industrialio_configfs`. If any of
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the modules is not present, follow the [instructions for recompiling
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kernel](#recompiling-kernel-with-industrial-io) below.
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Make sure you have the right kernel version. Since Linux 5.19, the
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dummy industrial I/O driver is broken. This will be probably fixed in
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Linux 6.6.
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If you have a broken kernel version, apply the
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[fix](./iio-dummy-fix.patch) and compile and install the modified
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kernel.
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If you want to use the modified module from here, compile it. In
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order to do this, you must have kernel development environment
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installed, for example:
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- Fedora or derivatives: `dnf install kernel-devel kernel-modules make`
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- Debian or derivatives: `apt install linux-headers-$(uname -r) make`
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- NixOS: `nix-shell '<nixpkgs>' -A linux.dev`
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Then you can compile the module, simply running `make` should work on
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most distributions.
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Insert a dummy industrial I/O kernel module. Either the stock one:
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```
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# modprobe iio-dummy
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```
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or the modified one from here:
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```
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# modprobe industrialio
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# modprobe industrialio_configfs
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# modprobe industrialio_sw_device
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# insmod ./iio-dummy-modified.ko
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```
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Find out where configfs is mounted: `mount | grep configfs`. It's
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typically `/sys/kernel/config`. If configfs is not mounted, mount it
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somewhere: `mount -t configfs none MOUNTPOINT`.
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Now you can create emulated industrial I/O devices with the stock driver:
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```
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# mkdir /sys/kernel/config/iio/devices/dummy/my-device
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```
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And/or with the modified driver from here:
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```
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# mkdir /sys/kernel/config/iio/devices/dummy-modified/my-device
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```
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If everything is OK then you can find the device in
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`/sys/bus/iio/devices/`.
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## Recompiling kernel with industrial I/O
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Making a custom kernel is different on each GNU/Linux distribution.
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The corresponding documentation can be found for example here:
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- Fedora: [https://fedoraproject.org/wiki/Building_a_custom_kernel](https://fedoraproject.org/wiki/Building_a_custom_kernel)
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- CentOS Stream: [https://wiki.centos.org/HowTos/BuildingKernelModules](https://wiki.centos.org/HowTos/BuildingKernelModules)
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(looks more useful for Fedora builds than CentOS)
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- Debian: [https://kernel-team.pages.debian.net/kernel-handbook/ch-common-tasks.html#s-common-official](https://kernel-team.pages.debian.net/kernel-handbook/ch-common-tasks.html#s-common-official)
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- NixOS: [https://nixos.wiki/wiki/Linux_kernel](https://nixos.wiki/wiki/Linux_kernel)
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Here are instructions for Fedora, similar steps can be used for other
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distributions, with distribution specifics as described in the links
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above. This is not necessarily the most official or the best way to
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do it but it's a way that *actually works* for me.
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Note on CentOS Stream 9: The kernel there doesn't contain the needed
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modules. Recompiling the kernel on CentOS Stream may be challenging
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due to missing build dependencies. If it doesn't work for you, you
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can try to use Fedora kernel and modules on CentOS Stream, including
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the dummy module compiled on Fedora.
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### Install kernel sources
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```
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# dnf install 'dnf-command(download)'
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$ dnf download --source kernel
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$ rpm -i kernel-*.src.rpm
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# dnf builddep ~/rpmbuild/SPECS/kernel.spec
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```
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### Change kernel configuration
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Not needed for current Fedora but may be needed for e.g. CentOS Stream.
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```
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# dnf install kernel-devel kernel-modules make rpm-build python3-devel ncurses-devel
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$ rpmbuild -bp ~/rpmbuild/SPECS/kernel.spec
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$ cd ~/rpmbuild/BUILD/kernel-*/linux-*/
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$ cp configs/kernel-VERSION-YOURARCH.config .config
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$ make nconfig
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```
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Configuration options that must be enabled:
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- Device Drivers -> Industrial I/O Support -> Enable IIO configuration via configfs
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- Device Drivers -> Industrial I/O Support -> Enable software IIO device support
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Optionally (you can use the alternative driver from here instead):
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- Device Drivers -> Industrial I/O Support -> IIO dummy drive -> An example driver with no hardware requirements
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Then copy `.config` back to its original file and don't forget to add
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the original architecture specification line there.
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### Apply the kernel fix
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If the kernel fix from here is needed, copy it to the sources:
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```
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cp .../iio-dummy-fix.patch ~/rpmbuild/SOURCES/
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```
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Edit `~/rpmbuild/SPECS/kernel.spec`:
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- Uncomment: `%define buildid .local`.
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- Add the patch file before: `Patch999999: linux-kernel-test.patch`.
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- Add the patch file before: `ApplyOptionalPatch linux-kernel-test.patch`.
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### Build the kernel
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You can use different options, if you don't need anything extra then
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the following builds the most important rpm's:
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```
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$ rpmbuild -bb --with baseonly --without debug --without debuginfo ~/rpmbuild/SPECS/kernel.spec
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```
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## Adding industrial I/O dummy module to your kernel
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If all you need is to add a missing stock I/O dummy module, you can
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try to compile just the module. Switch to kernel sources and run:
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```
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$ make oldconfig
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$ make prepare
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$ make modules_prepare
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$ make M=drivers/iio/dummy
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```
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And insert the module:
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```
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# modprobe industrialio
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# modprobe industrialio_configfs
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# modprobe industrialio_sw_device
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# insmod ./drivers/iio/dummy/iio-dummy.ko
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```
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If this fails, inspect `dmesg` output and try to figure out what's
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wrong. If this fails too, rebuild the whole kernel with the given
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module enabled.
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55
crates/scmi/kernel/iio-dummy/iio-dummy-fix.patch
Normal file
55
crates/scmi/kernel/iio-dummy/iio-dummy-fix.patch
Normal file
@ -0,0 +1,55 @@
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Commit 813665564b3d ("iio: core: Convert to use firmware node handle
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instead of OF node") switched the kind of nodes to use for label
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retrieval in device registration. Probably an unwanted change in that
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commit was that if the device has no parent then NULL pointer is
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accessed. This is what happens in the stock IIO dummy driver when a
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new entry is created in configfs:
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# mkdir /sys/kernel/config/iio/devices/dummy/foo
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BUG: kernel NULL pointer dereference, address: ...
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...
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Call Trace:
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__iio_device_register
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iio_dummy_probe
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Since there seems to be no reason to make a parent device of an IIO
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dummy device mandatory, let’s prevent the invalid memory access in
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__iio_device_register when the parent device is NULL. With this
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change, the IIO dummy driver works fine with configfs.
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Fixes: 813665564b3d ("iio: core: Convert to use firmware node handle instead of OF node")
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Reviewed-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
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Signed-off-by: Milan Zamazal <mzamazal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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---
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drivers/iio/industrialio-core.c | 5 +++--
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1 file changed, 3 insertions(+), 2 deletions(-)
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diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
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index c117f50d0cf3..adcba832e6fa 100644
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--- a/drivers/iio/industrialio-core.c
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+++ b/drivers/iio/industrialio-core.c
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@@ -1888,7 +1888,7 @@ static const struct iio_buffer_setup_ops noop_ring_setup_ops;
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int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
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{
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struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
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- struct fwnode_handle *fwnode;
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+ struct fwnode_handle *fwnode = NULL;
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int ret;
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if (!indio_dev->info)
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@@ -1899,7 +1899,8 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
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/* If the calling driver did not initialize firmware node, do it here */
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if (dev_fwnode(&indio_dev->dev))
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fwnode = dev_fwnode(&indio_dev->dev);
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- else
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+ /* The default dummy IIO device has no parent */
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+ else if (indio_dev->dev.parent)
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fwnode = dev_fwnode(indio_dev->dev.parent);
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device_set_node(&indio_dev->dev, fwnode);
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--
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2.40.1
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693
crates/scmi/kernel/iio-dummy/iio_modified_dummy.c
Normal file
693
crates/scmi/kernel/iio-dummy/iio_modified_dummy.c
Normal file
@ -0,0 +1,693 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2011 Jonathan Cameron
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*
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* A reference industrial I/O driver to illustrate the functionality available.
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*
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* There are numerous real drivers to illustrate the finer points.
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* The purpose of this driver is to provide a driver with far more comments
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* and explanatory notes than any 'real' driver would have.
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* Anyone starting out writing an IIO driver should first make sure they
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* understand all of this driver except those bits specifically marked
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* as being present to allow us to 'fake' the presence of hardware.
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*
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* Changes by Milan Zamazal <mzamazal@redhat.com> 2023, for testing
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* with vhost-device-scmi:
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*
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* - Dropped conditional parts.
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* - Use 3 axes in the accelerometer device.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/events.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/sw_device.h>
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#include "iio_modified_dummy.h"
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static const struct config_item_type iio_dummy_type = {
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.ct_owner = THIS_MODULE,
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};
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/**
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* struct iio_dummy_accel_calibscale - realworld to register mapping
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* @val: first value in read_raw - here integer part.
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* @val2: second value in read_raw etc - here micro part.
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* @regval: register value - magic device specific numbers.
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*/
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struct iio_dummy_accel_calibscale {
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int val;
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int val2;
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int regval; /* what would be written to hardware */
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};
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static const struct iio_dummy_accel_calibscale dummy_scales[] = {
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{ 0, 100, 0x8 }, /* 0.000100 */
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{ 0, 133, 0x7 }, /* 0.000133 */
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{ 733, 13, 0x9 }, /* 733.000013 */
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};
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/*
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* iio_dummy_channels - Description of available channels
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*
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* This array of structures tells the IIO core about what the device
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* actually provides for a given channel.
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*/
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static const struct iio_chan_spec iio_dummy_channels[] = {
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/* indexed ADC channel in_voltage0_raw etc */
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{
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.type = IIO_VOLTAGE,
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/* Channel has a numeric index of 0 */
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.indexed = 1,
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.channel = 0,
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/* What other information is available? */
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.info_mask_separate =
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/*
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* in_voltage0_raw
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* Raw (unscaled no bias removal etc) measurement
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* from the device.
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*/
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BIT(IIO_CHAN_INFO_RAW) |
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/*
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* in_voltage0_offset
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* Offset for userspace to apply prior to scale
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* when converting to standard units (microvolts)
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*/
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BIT(IIO_CHAN_INFO_OFFSET) |
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/*
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* in_voltage0_scale
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* Multipler for userspace to apply post offset
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* when converting to standard units (microvolts)
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*/
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BIT(IIO_CHAN_INFO_SCALE),
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/*
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* sampling_frequency
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* The frequency in Hz at which the channels are sampled
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*/
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.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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/* The ordering of elements in the buffer via an enum */
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.scan_index = DUMMY_INDEX_VOLTAGE_0,
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.scan_type = { /* Description of storage in buffer */
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.sign = 'u', /* unsigned */
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.realbits = 13, /* 13 bits */
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.storagebits = 16, /* 16 bits used for storage */
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.shift = 0, /* zero shift */
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},
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},
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/* Differential ADC channel in_voltage1-voltage2_raw etc*/
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{
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.type = IIO_VOLTAGE,
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.differential = 1,
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/*
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* Indexing for differential channels uses channel
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* for the positive part, channel2 for the negative.
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*/
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.indexed = 1,
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.channel = 1,
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.channel2 = 2,
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/*
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* in_voltage1-voltage2_raw
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* Raw (unscaled no bias removal etc) measurement
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* from the device.
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*/
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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/*
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* in_voltage-voltage_scale
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* Shared version of scale - shared by differential
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* input channels of type IIO_VOLTAGE.
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*/
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
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/*
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* sampling_frequency
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* The frequency in Hz at which the channels are sampled
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*/
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.scan_index = DUMMY_INDEX_DIFFVOLTAGE_1M2,
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.scan_type = { /* Description of storage in buffer */
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.sign = 's', /* signed */
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.realbits = 12, /* 12 bits */
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.storagebits = 16, /* 16 bits used for storage */
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.shift = 0, /* zero shift */
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},
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},
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/* Differential ADC channel in_voltage3-voltage4_raw etc*/
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{
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.type = IIO_VOLTAGE,
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.differential = 1,
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.indexed = 1,
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.channel = 3,
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.channel2 = 4,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
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.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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.scan_index = DUMMY_INDEX_DIFFVOLTAGE_3M4,
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.scan_type = {
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.sign = 's',
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.realbits = 11,
|
||||
.storagebits = 16,
|
||||
.shift = 0,
|
||||
},
|
||||
},
|
||||
/*
|
||||
* 'modified' (i.e. axis specified) acceleration channel
|
||||
* in_accel_[xyz]_raw
|
||||
*/
|
||||
{
|
||||
.type = IIO_ACCEL,
|
||||
.modified = 1,
|
||||
/* Channel 2 is use for modifiers */
|
||||
.channel2 = IIO_MOD_X,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
||||
/*
|
||||
* Internal bias and gain correction values. Applied
|
||||
* by the hardware or driver prior to userspace
|
||||
* seeing the readings. Typically part of hardware
|
||||
* calibration.
|
||||
*/
|
||||
BIT(IIO_CHAN_INFO_CALIBSCALE) |
|
||||
BIT(IIO_CHAN_INFO_CALIBBIAS),
|
||||
.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
|
||||
.scan_index = DUMMY_INDEX_ACCEL_X,
|
||||
.scan_type = { /* Description of storage in buffer */
|
||||
.sign = 's', /* signed */
|
||||
.realbits = 16, /* 16 bits */
|
||||
.storagebits = 16, /* 16 bits used for storage */
|
||||
.shift = 0, /* zero shift */
|
||||
},
|
||||
},
|
||||
{
|
||||
.type = IIO_ACCEL,
|
||||
.modified = 1,
|
||||
/* Channel 2 is use for modifiers */
|
||||
.channel2 = IIO_MOD_Y,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
||||
BIT(IIO_CHAN_INFO_CALIBSCALE) |
|
||||
BIT(IIO_CHAN_INFO_CALIBBIAS),
|
||||
.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
|
||||
.scan_index = DUMMY_INDEX_ACCEL_Y,
|
||||
.scan_type = { /* Description of storage in buffer */
|
||||
.sign = 's', /* signed */
|
||||
.realbits = 16, /* 16 bits */
|
||||
.storagebits = 16, /* 16 bits used for storage */
|
||||
.shift = 0, /* zero shift */
|
||||
},
|
||||
},
|
||||
{
|
||||
.type = IIO_ACCEL,
|
||||
.modified = 1,
|
||||
/* Channel 2 is use for modifiers */
|
||||
.channel2 = IIO_MOD_Z,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
||||
BIT(IIO_CHAN_INFO_CALIBSCALE) |
|
||||
BIT(IIO_CHAN_INFO_CALIBBIAS),
|
||||
.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
|
||||
.scan_index = DUMMY_INDEX_ACCEL_Z,
|
||||
.scan_type = { /* Description of storage in buffer */
|
||||
.sign = 's', /* signed */
|
||||
.realbits = 16, /* 16 bits */
|
||||
.storagebits = 16, /* 16 bits used for storage */
|
||||
.shift = 0, /* zero shift */
|
||||
},
|
||||
},
|
||||
/*
|
||||
* Convenience macro for timestamps. 4 is the index in
|
||||
* the buffer.
|
||||
*/
|
||||
IIO_CHAN_SOFT_TIMESTAMP(4),
|
||||
/* DAC channel out_voltage0_raw */
|
||||
{
|
||||
.type = IIO_VOLTAGE,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
||||
.scan_index = -1, /* No buffer support */
|
||||
.output = 1,
|
||||
.indexed = 1,
|
||||
.channel = 0,
|
||||
},
|
||||
{
|
||||
.type = IIO_STEPS,
|
||||
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_ENABLE) |
|
||||
BIT(IIO_CHAN_INFO_CALIBHEIGHT),
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
|
||||
.scan_index = -1, /* No buffer support */
|
||||
},
|
||||
{
|
||||
.type = IIO_ACTIVITY,
|
||||
.modified = 1,
|
||||
.channel2 = IIO_MOD_RUNNING,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
|
||||
.scan_index = -1, /* No buffer support */
|
||||
},
|
||||
{
|
||||
.type = IIO_ACTIVITY,
|
||||
.modified = 1,
|
||||
.channel2 = IIO_MOD_WALKING,
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
|
||||
.scan_index = -1, /* No buffer support */
|
||||
},
|
||||
};
|
||||
|
||||
/**
|
||||
* iio_dummy_read_raw() - data read function.
|
||||
* @indio_dev: the struct iio_dev associated with this device instance
|
||||
* @chan: the channel whose data is to be read
|
||||
* @val: first element of returned value (typically INT)
|
||||
* @val2: second element of returned value (typically MICRO)
|
||||
* @mask: what we actually want to read as per the info_mask_*
|
||||
* in iio_chan_spec.
|
||||
*/
|
||||
static int iio_dummy_read_raw(struct iio_dev *indio_dev,
|
||||
struct iio_chan_spec const *chan,
|
||||
int *val,
|
||||
int *val2,
|
||||
long mask)
|
||||
{
|
||||
struct iio_dummy_state *st = iio_priv(indio_dev);
|
||||
int ret = -EINVAL;
|
||||
|
||||
mutex_lock(&st->lock);
|
||||
switch (mask) {
|
||||
case IIO_CHAN_INFO_RAW: /* magic value - channel value read */
|
||||
switch (chan->type) {
|
||||
case IIO_VOLTAGE:
|
||||
if (chan->output) {
|
||||
/* Set integer part to cached value */
|
||||
*val = st->dac_val;
|
||||
ret = IIO_VAL_INT;
|
||||
} else if (chan->differential) {
|
||||
if (chan->channel == 1)
|
||||
*val = st->differential_adc_val[0];
|
||||
else
|
||||
*val = st->differential_adc_val[1];
|
||||
ret = IIO_VAL_INT;
|
||||
} else {
|
||||
*val = st->single_ended_adc_val;
|
||||
ret = IIO_VAL_INT;
|
||||
}
|
||||
break;
|
||||
case IIO_ACCEL:
|
||||
switch(chan->scan_index) {
|
||||
case DUMMY_INDEX_ACCEL_X:
|
||||
*val = st->accel_val[0];
|
||||
break;
|
||||
case DUMMY_INDEX_ACCEL_Y:
|
||||
*val = st->accel_val[1];
|
||||
break;
|
||||
case DUMMY_INDEX_ACCEL_Z:
|
||||
*val = st->accel_val[2];
|
||||
break;
|
||||
default:
|
||||
*val = 0;
|
||||
}
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
case IIO_CHAN_INFO_PROCESSED:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
*val = st->steps;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
case IIO_ACTIVITY:
|
||||
switch (chan->channel2) {
|
||||
case IIO_MOD_RUNNING:
|
||||
*val = st->activity_running;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
case IIO_MOD_WALKING:
|
||||
*val = st->activity_walking;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
case IIO_CHAN_INFO_OFFSET:
|
||||
/* only single ended adc -> 7 */
|
||||
*val = 7;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
case IIO_CHAN_INFO_SCALE:
|
||||
switch (chan->type) {
|
||||
case IIO_VOLTAGE:
|
||||
switch (chan->differential) {
|
||||
case 0:
|
||||
/* only single ended adc -> 0.001333 */
|
||||
*val = 0;
|
||||
*val2 = 1333;
|
||||
ret = IIO_VAL_INT_PLUS_MICRO;
|
||||
break;
|
||||
case 1:
|
||||
/* all differential adc -> 0.000001344 */
|
||||
*val = 0;
|
||||
*val2 = 1344;
|
||||
ret = IIO_VAL_INT_PLUS_NANO;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
case IIO_CHAN_INFO_CALIBBIAS:
|
||||
/* only the acceleration axis - read from cache */
|
||||
*val = st->accel_calibbias;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
case IIO_CHAN_INFO_CALIBSCALE:
|
||||
*val = st->accel_calibscale->val;
|
||||
*val2 = st->accel_calibscale->val2;
|
||||
ret = IIO_VAL_INT_PLUS_MICRO;
|
||||
break;
|
||||
case IIO_CHAN_INFO_SAMP_FREQ:
|
||||
*val = 3;
|
||||
*val2 = 33;
|
||||
ret = IIO_VAL_INT_PLUS_NANO;
|
||||
break;
|
||||
case IIO_CHAN_INFO_ENABLE:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
*val = st->steps_enabled;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
case IIO_CHAN_INFO_CALIBHEIGHT:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
*val = st->height;
|
||||
ret = IIO_VAL_INT;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
break;
|
||||
|
||||
default:
|
||||
break;
|
||||
}
|
||||
mutex_unlock(&st->lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* iio_dummy_write_raw() - data write function.
|
||||
* @indio_dev: the struct iio_dev associated with this device instance
|
||||
* @chan: the channel whose data is to be written
|
||||
* @val: first element of value to set (typically INT)
|
||||
* @val2: second element of value to set (typically MICRO)
|
||||
* @mask: what we actually want to write as per the info_mask_*
|
||||
* in iio_chan_spec.
|
||||
*
|
||||
* Note that all raw writes are assumed IIO_VAL_INT and info mask elements
|
||||
* are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt
|
||||
* in struct iio_info is provided by the driver.
|
||||
*/
|
||||
static int iio_dummy_write_raw(struct iio_dev *indio_dev,
|
||||
struct iio_chan_spec const *chan,
|
||||
int val,
|
||||
int val2,
|
||||
long mask)
|
||||
{
|
||||
int i;
|
||||
int ret = 0;
|
||||
struct iio_dummy_state *st = iio_priv(indio_dev);
|
||||
|
||||
switch (mask) {
|
||||
case IIO_CHAN_INFO_RAW:
|
||||
switch (chan->type) {
|
||||
case IIO_VOLTAGE:
|
||||
if (chan->output == 0)
|
||||
return -EINVAL;
|
||||
|
||||
/* Locking not required as writing single value */
|
||||
mutex_lock(&st->lock);
|
||||
st->dac_val = val;
|
||||
mutex_unlock(&st->lock);
|
||||
return 0;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
case IIO_CHAN_INFO_PROCESSED:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
mutex_lock(&st->lock);
|
||||
st->steps = val;
|
||||
mutex_unlock(&st->lock);
|
||||
return 0;
|
||||
case IIO_ACTIVITY:
|
||||
if (val < 0)
|
||||
val = 0;
|
||||
if (val > 100)
|
||||
val = 100;
|
||||
switch (chan->channel2) {
|
||||
case IIO_MOD_RUNNING:
|
||||
st->activity_running = val;
|
||||
return 0;
|
||||
case IIO_MOD_WALKING:
|
||||
st->activity_walking = val;
|
||||
return 0;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
case IIO_CHAN_INFO_CALIBSCALE:
|
||||
mutex_lock(&st->lock);
|
||||
/* Compare against table - hard matching here */
|
||||
for (i = 0; i < ARRAY_SIZE(dummy_scales); i++)
|
||||
if (val == dummy_scales[i].val &&
|
||||
val2 == dummy_scales[i].val2)
|
||||
break;
|
||||
if (i == ARRAY_SIZE(dummy_scales))
|
||||
ret = -EINVAL;
|
||||
else
|
||||
st->accel_calibscale = &dummy_scales[i];
|
||||
mutex_unlock(&st->lock);
|
||||
return ret;
|
||||
case IIO_CHAN_INFO_CALIBBIAS:
|
||||
mutex_lock(&st->lock);
|
||||
st->accel_calibbias = val;
|
||||
mutex_unlock(&st->lock);
|
||||
return 0;
|
||||
case IIO_CHAN_INFO_ENABLE:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
mutex_lock(&st->lock);
|
||||
st->steps_enabled = val;
|
||||
mutex_unlock(&st->lock);
|
||||
return 0;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
case IIO_CHAN_INFO_CALIBHEIGHT:
|
||||
switch (chan->type) {
|
||||
case IIO_STEPS:
|
||||
st->height = val;
|
||||
return 0;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Device type specific information.
|
||||
*/
|
||||
static const struct iio_info iio_dummy_info = {
|
||||
.read_raw = &iio_dummy_read_raw,
|
||||
.write_raw = &iio_dummy_write_raw,
|
||||
};
|
||||
|
||||
/**
|
||||
* iio_dummy_init_device() - device instance specific init
|
||||
* @indio_dev: the iio device structure
|
||||
*
|
||||
* Most drivers have one of these to set up default values,
|
||||
* reset the device to known state etc.
|
||||
*/
|
||||
static int iio_dummy_init_device(struct iio_dev *indio_dev)
|
||||
{
|
||||
struct iio_dummy_state *st = iio_priv(indio_dev);
|
||||
|
||||
st->dac_val = 0;
|
||||
st->single_ended_adc_val = 73;
|
||||
st->differential_adc_val[0] = 33;
|
||||
st->differential_adc_val[1] = -34;
|
||||
st->accel_val[0] = 34;
|
||||
st->accel_val[1] = 37;
|
||||
st->accel_val[2] = 40;
|
||||
st->accel_calibbias = -7;
|
||||
st->accel_calibscale = &dummy_scales[0];
|
||||
st->steps = 47;
|
||||
st->activity_running = 98;
|
||||
st->activity_walking = 4;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* iio_dummy_probe() - device instance probe
|
||||
* @name: name of this instance.
|
||||
*
|
||||
* Arguments are bus type specific.
|
||||
* I2C: iio_dummy_probe(struct i2c_client *client,
|
||||
* const struct i2c_device_id *id)
|
||||
* SPI: iio_dummy_probe(struct spi_device *spi)
|
||||
*/
|
||||
static struct iio_sw_device *iio_dummy_probe(const char *name)
|
||||
{
|
||||
int ret;
|
||||
struct iio_dev *indio_dev;
|
||||
struct iio_dummy_state *st;
|
||||
struct iio_sw_device *swd;
|
||||
struct device *parent;
|
||||
|
||||
/*
|
||||
* With hardware: Set the parent device.
|
||||
* parent = &spi->dev;
|
||||
* parent = &client->dev;
|
||||
*/
|
||||
|
||||
swd = kzalloc(sizeof(*swd), GFP_KERNEL);
|
||||
if (!swd)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
/*
|
||||
* Allocate an IIO device.
|
||||
*
|
||||
* This structure contains all generic state
|
||||
* information about the device instance.
|
||||
* It also has a region (accessed by iio_priv()
|
||||
* for chip specific state information.
|
||||
*/
|
||||
indio_dev = iio_device_alloc(parent, sizeof(*st));
|
||||
if (!indio_dev) {
|
||||
ret = -ENOMEM;
|
||||
goto error_free_swd;
|
||||
}
|
||||
|
||||
st = iio_priv(indio_dev);
|
||||
mutex_init(&st->lock);
|
||||
|
||||
iio_dummy_init_device(indio_dev);
|
||||
|
||||
/*
|
||||
* Make the iio_dev struct available to remove function.
|
||||
* Bus equivalents
|
||||
* i2c_set_clientdata(client, indio_dev);
|
||||
* spi_set_drvdata(spi, indio_dev);
|
||||
*/
|
||||
swd->device = indio_dev;
|
||||
|
||||
/*
|
||||
* Set the device name.
|
||||
*
|
||||
* This is typically a part number and obtained from the module
|
||||
* id table.
|
||||
* e.g. for i2c and spi:
|
||||
* indio_dev->name = id->name;
|
||||
* indio_dev->name = spi_get_device_id(spi)->name;
|
||||
*/
|
||||
indio_dev->name = kstrdup(name, GFP_KERNEL);
|
||||
if (!indio_dev->name) {
|
||||
ret = -ENOMEM;
|
||||
goto error_free_device;
|
||||
}
|
||||
|
||||
/* Provide description of available channels */
|
||||
indio_dev->channels = iio_dummy_channels;
|
||||
indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels);
|
||||
|
||||
/*
|
||||
* Provide device type specific interface functions and
|
||||
* constant data.
|
||||
*/
|
||||
indio_dev->info = &iio_dummy_info;
|
||||
|
||||
/* Specify that device provides sysfs type interfaces */
|
||||
indio_dev->modes = INDIO_DIRECT_MODE;
|
||||
|
||||
ret = iio_device_register(indio_dev);
|
||||
if (ret < 0)
|
||||
goto error_free_name;
|
||||
|
||||
iio_swd_group_init_type_name(swd, name, &iio_dummy_type);
|
||||
|
||||
return swd;
|
||||
error_free_name:
|
||||
kfree(indio_dev->name);
|
||||
error_free_device:
|
||||
iio_device_free(indio_dev);
|
||||
error_free_swd:
|
||||
kfree(swd);
|
||||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
/**
|
||||
* iio_dummy_remove() - device instance removal function
|
||||
* @swd: pointer to software IIO device abstraction
|
||||
*
|
||||
* Parameters follow those of iio_dummy_probe for buses.
|
||||
*/
|
||||
static int iio_dummy_remove(struct iio_sw_device *swd)
|
||||
{
|
||||
/*
|
||||
* Get a pointer to the device instance iio_dev structure
|
||||
* from the bus subsystem. E.g.
|
||||
* struct iio_dev *indio_dev = i2c_get_clientdata(client);
|
||||
* struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
||||
*/
|
||||
struct iio_dev *indio_dev = swd->device;
|
||||
|
||||
/* Unregister the device */
|
||||
iio_device_unregister(indio_dev);
|
||||
|
||||
/* Free all structures */
|
||||
kfree(indio_dev->name);
|
||||
iio_device_free(indio_dev);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* module_iio_sw_device_driver() - device driver registration
|
||||
*
|
||||
* Varies depending on bus type of the device. As there is no device
|
||||
* here, call probe directly. For information on device registration
|
||||
* i2c:
|
||||
* Documentation/i2c/writing-clients.rst
|
||||
* spi:
|
||||
* Documentation/spi/spi-summary.rst
|
||||
*/
|
||||
static const struct iio_sw_device_ops iio_dummy_device_ops = {
|
||||
.probe = iio_dummy_probe,
|
||||
.remove = iio_dummy_remove,
|
||||
};
|
||||
|
||||
static struct iio_sw_device_type iio_dummy_device = {
|
||||
.name = "dummy-modified",
|
||||
.owner = THIS_MODULE,
|
||||
.ops = &iio_dummy_device_ops,
|
||||
};
|
||||
|
||||
module_iio_sw_device_driver(iio_dummy_device);
|
||||
|
||||
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
|
||||
MODULE_DESCRIPTION("IIO dummy driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
68
crates/scmi/kernel/iio-dummy/iio_modified_dummy.h
Normal file
68
crates/scmi/kernel/iio-dummy/iio_modified_dummy.h
Normal file
@ -0,0 +1,68 @@
|
||||
/* SPDX-License-Identifier: GPL-2.0-only */
|
||||
/**
|
||||
* Copyright (c) 2011 Jonathan Cameron
|
||||
*
|
||||
* Join together the various functionality of iio_modified_dummy driver
|
||||
*
|
||||
* Changes by Milan Zamazal <mzamazal@redhat.com> 2023, for testing
|
||||
* with vhost-device-scmi:
|
||||
*
|
||||
* - Dropped conditional parts.
|
||||
* - Use 3 axes in the accelerometer device.
|
||||
*/
|
||||
|
||||
#ifndef _IIO_MODIFIED_DUMMY_H_
|
||||
#define _IIO_MODIFIED_DUMMY_H_
|
||||
#include <linux/kernel.h>
|
||||
|
||||
struct iio_dummy_accel_calibscale;
|
||||
struct iio_dummy_regs;
|
||||
|
||||
/**
|
||||
* struct iio_dummy_state - device instance specific state.
|
||||
* @dac_val: cache for dac value
|
||||
* @single_ended_adc_val: cache for single ended adc value
|
||||
* @differential_adc_val: cache for differential adc value
|
||||
* @accel_val: cache for acceleration value
|
||||
* @accel_calibbias: cache for acceleration calibbias
|
||||
* @accel_calibscale: cache for acceleration calibscale
|
||||
* @lock: lock to ensure state is consistent
|
||||
* @event_irq: irq number for event line (faked)
|
||||
* @event_val: cache for event threshold value
|
||||
* @event_en: cache of whether event is enabled
|
||||
*/
|
||||
struct iio_dummy_state {
|
||||
int dac_val;
|
||||
int single_ended_adc_val;
|
||||
int differential_adc_val[2];
|
||||
int accel_val[3];
|
||||
int accel_calibbias;
|
||||
int activity_running;
|
||||
int activity_walking;
|
||||
const struct iio_dummy_accel_calibscale *accel_calibscale;
|
||||
struct mutex lock;
|
||||
struct iio_dummy_regs *regs;
|
||||
int steps_enabled;
|
||||
int steps;
|
||||
int height;
|
||||
};
|
||||
|
||||
/**
|
||||
* enum iio_modified_dummy_scan_elements - scan index enum
|
||||
* @DUMMY_INDEX_VOLTAGE_0: the single ended voltage channel
|
||||
* @DUMMY_INDEX_DIFFVOLTAGE_1M2: first differential channel
|
||||
* @DUMMY_INDEX_DIFFVOLTAGE_3M4: second differential channel
|
||||
* @DUMMY_INDEX_ACCELX: acceleration channel
|
||||
*
|
||||
* Enum provides convenient numbering for the scan index.
|
||||
*/
|
||||
enum iio_modified_dummy_scan_elements {
|
||||
DUMMY_INDEX_VOLTAGE_0,
|
||||
DUMMY_INDEX_DIFFVOLTAGE_1M2,
|
||||
DUMMY_INDEX_DIFFVOLTAGE_3M4,
|
||||
DUMMY_INDEX_ACCEL_X,
|
||||
DUMMY_INDEX_ACCEL_Y,
|
||||
DUMMY_INDEX_ACCEL_Z,
|
||||
};
|
||||
|
||||
#endif /* _IIO_MODIFIED_DUMMY_H_ */
|
||||
Loading…
Reference in New Issue
Block a user