[v2,0/5] memory: brcmstb_dpfe: support DPFE API v4

Message

Markus Mayer Jan. 19, 2024, 9:52 p.m. UTC

It has become necessary to distinguish between the various DPFE API
versions by version number. Having just chip-specific compatible strings
no longer meeting our needs. Furthermore, the generic compatible string
"brcm,dpfe-cpu" is being removed as it doesn't serve any actual purpose.
Finally, a new DPFE API version, v4, needs to be supported by the
driver.

To select between the different API versions, a new compatible string
format is being introduced: brcm,dpfe-cpu-v<N> where <N> represents the
API version number.

This approach is needed, because the API version has changed in the past
for some chip, which means it cannot be derived reliably just based on
the chip name.

We rely on the boot firmware to populate Device Tree with the proper
compatible string for the correct DPFE API version. The boot firmware
already has this information and can easily pass it to the kernel in
this manner.

Changes since v1:
  - remove compatible string brcm,dpfe-cpu
  - add compatible strings brcm,bcm7278-dpfe-cpu, brcm,bcm7211-dpfe-cpu
  - add "description" section to the binding
  - drop patch that contained API probing and detection code
  - tweak and clarify a few code comments

Markus Mayer (5):
  dt-bindings: memory: remove generic compatible string brcm,dpfe-cpu
  dt-bindings: memory: add two chip-specific compatible string
  dt-bindings: memory: additional compatible strings for Broadcom DPFE
  memory: brcmstb_dpfe: introduce version-specific compatible strings
  memory: brcmstb_dpfe: support DPFE API v4

 .../memory-controllers/brcm,dpfe-cpu.yaml     | 24 ++++++++++-
 drivers/memory/brcmstb_dpfe.c                 | 41 ++++++++++++++++++-
 2 files changed, 62 insertions(+), 3 deletions(-)