[v8,00/10] ACPI _CRS CSI-2 and MIPI DisCo for Imaging support

Hello all,

Here's an implementation of ACPI 6.4 _CRS CSI-2 resource descriptor and
MIPI DisCo for Imaging 1.0 [1]. What the two basically provide is an
officially sanctioned way to describe CSI-2 connected cameras to operating
system software, something DT based systems have enjoyed for quite some
time already.

The implementation digs the information from ACPI tables (_CRS descriptors
and data + property extensions) and constructs software nodes that are
compatible with Documentation/firmware-guide/acpi/dsd/graph.rst and
Documentation/devicetree/bindings/media/video-interface-devices.yaml . No
specific driver changes are needed.

The first patch of the set also removes the second namespace walk from DSDT
root.

[1] https://www.mipi.org/specifications/mipi-disco-imaging

since v7:

- Release _CRS CSI2 resource list directly from acpi_scan_bus(), calling
  acpi_bus_scan_crs_csi2_release(), instead of acpi_bus_scan_crs_csi2()
  doing it.

- Change first "for" to "because" in comment explaining node allocation.

- Move list heads to the beginning of the struct where possible.

- Use Andy's rework of the NEXT_PROPERTY() macro.

- Unwrap acpi_bus_device_postpone() definition.

- Define MIPI_IMG_PORT_PREFIX when the string is needed instead of changing
  the just added definition.

since v6:

- Avoid including an extra patch in the set. Otherwise the set is unchanged.

since v5:

- Add a high level description of the mipi.c file in the heading.

- Add a missing memory allocation check (thanks to Dan Carpenter).

- Prepend a patch to the set that removes the second ACPI namespace walk due
  _DEP. Instead, the devices that can't be initialised yet are collected to
  a linked list that is revisited after initialising the rest of the
  devices.

- Collect information on _CRS CSI2 records during the same, single namespace
  walk. Effectively since v5, two namespace walks from the namespace root
  are removed.

- The former requires passing state information between functions during the
  _DSD property initialisation, among other things, introducing additional
  function arguments in _DSD parsing functions.

- The order of the patches has changed somewhat, as the parsing process has
  changed. Also a patch has been added to collect ACPI devices for which
  software nodes need to be initialised for DisCo for Imaging.

- Elsewhere, acpi_bus_scan() becomes easier to grasp. Comments are also
  added in acpi_bus_scan() to explain what is being done.

- Change the wrong node type warning from acpi_parse_string_ref() to use
  debug level.

since v4:

- Add leading dots to comment sentences.

- Use UINT_MAX - 1 to denote an unallocated port instead of ~1U.

- Unwrap a line.

- Get ACPI handle into a local variable in acpi_init_swnodes() for easier
  use, use acpi_device_handle() to obtain it.

- Rework "rotation" property checking and _PLD object access.

- Also obtain return value of acpi_get_name() into a local variable before
  testing it.

- Use a local variable for the first element string pointer in
  acpi_properties_prepare_mipi().

since v3:

- Add comments to data structures and functions, code inside functions.

- Use ACPI_FAILURE() for testing ACPI framework function return values.

- Unwrap a few lines.

- Rename list heads as "head", some were called just "list".

- Count ACPI handles related to _CRS CSI2 resources during tree walk.

- Reshape testing for CSI-2 port allocation in next_csi2_port_index().

- Move allocation of software nodes into a new function,
  acpi_crs_csi2_alloc_fill_swnodes().

- Comments: acpi_bus_scan_crs_csi2() is to be called on the namespace
  root.

- Use size_t for this_count variable in acpi_bus_scan_crs_csi2().

- Revert the NEXT_PROPERTY() macro condition to original (the suggested
  one was different).

- Remove u union in init_port_csi2_common().

- Fix val array size in init_port_csi2_common(). This issue was masked by
  the presence of a u32 field in the union.

- Use "-" for copyright year range.

since v2:

- Unwrap a few lines.

- Copy CSI-2 resource source string using strscpy() instead of memcpy() in
  scan_check_crs_csi2_instance.

- Fix GRAPH_PORT_NAME() sanity check bug introduced in v2.

- Fix snprintf() return value check for port node name in
  get_mipi_port_handle().

- Fix mipi-img-lane-polarities reading.

- Cast bit value to bool instead of using ... ? 1U : 0U.

- Get primary fwnode using acpi_fwnode_handle().

- Don't use MIPI_IMG_PREFIX in the array of renamed properties.

- Use tabs for indenting drivers/acpi/property.c authors.

- Add a comment on assigning ACPI device's secondary fwnode and assign
  ACPI device's secondary fwnode straight to NULL when unassigning it.

since v1:

- Update copyright notices.

- Include linux/types.h instead of linux/kernel.h in drivers/acpi/mipi.c.

- Use SWNODE_GRAPH_PORT_NAME_FMT instead of plain "port@%u" in
  GRAPH_PORT_NAME macro.

- Make the condition in NEXT_PROPERTY() macro easier to read.

- Unwrap lines to make them moderately longer than 80 characters.

- Use * BITS_PER_TYPE(u8) instead of << 3 to convert bytes to bits in
  init_port_csi2_common().

- Test ACPI framework call success using ACPI_SUCCESS() instead of
  comparing with AE_OK. Likewise for ACPI_FAILURE and != AE_OK.

- Use newly added SOFTWARE_NODE() macro to construct the root software
  node.

- Use str_has_prefix() to test for a string prefix instead of memcmp().

- Add pr_fmt() macro to drivers/acpi/property.c.

- Move logical or operators to the end of the line in
  acpi_properties_prepare().

- Improve bad node type error in acpi_parse_string_ref().

Sakari Ailus (10):
  ACPI: scan: Remove the second DSDT traversal
  ACPI: property: Parse data node string references in properties
  ACPI: property: Parse _CRS CSI-2 descriptor
  device property: Add SOFTWARE_NODE() macro for defining software nodes
  ACPI: property: Prepare generating swnodes for ACPI and DisCo for
    Imaging
  ACPI: scan: Generate software nodes based on MIPI DisCo for Imaging
  ACPI: property: Dig "rotation" property for devices with CSI2 _CRS
  ACPI: property: Rename parsed MIPI DisCo for Imaging properties
  ACPI: property: Skip MIPI property table without "mipi-img" prefix
  ACPI: property: Document _CRS CSI-2 and DisCo for Imaging support

 drivers/acpi/Makefile    |   2 +-
 drivers/acpi/internal.h  |  41 +-
 drivers/acpi/mipi.c      | 796 +++++++++++++++++++++++++++++++++++++++
 drivers/acpi/power.c     |   2 +-
 drivers/acpi/property.c  | 180 +++++++--
 drivers/acpi/scan.c      | 227 +++++++++--
 include/acpi/acpi_bus.h  |  82 ++++
 include/linux/property.h |   7 +
 8 files changed, 1252 insertions(+), 85 deletions(-)
 create mode 100644 drivers/acpi/mipi.c

On Wed, Mar 29, 2023 at 01:09:46PM +0300, Sakari Ailus wrote:
> Prepare generating software nodes for information parsed from ACPI _CRS for
> CSI-2 as well as MIPI DisCo for Imaging spec. The software nodes are
> compliant with existing ACPI or DT definitions and are parsed by relevant
> drivers without changes.

There is discussion is ongoing in the previous version of the series for this
patch.