[00/26] Add support for QMC HDLC, framer infrastruture and PEF2256 framer

Hi,

I have a system where I need to handle an HDLC interface and some audio
data.

The HDLC data are transferred using a TDM bus on which a PEF2256
(E1/T1 framer) is present. The PEF2256 transfers data from/to the TDM
bus to/from the E1 line. This PEF2256 is connected to a PowerQUICC SoC
for the control path and the TDM is connected to the SoC (QMC component)
for the data path.

>From the QMC HDLC driver, I need to handle HDLC data using the QMC,
carrier detection using the PEF2256 (E1 line carrier) and set/get some
PEF2256 configuration.

The QMC HDLC driver considers the PEF2256 as a generic framer.
It performs operations that involve the PEF2256 through the generic
framer API.

The audio data are exchanged with the PEF2256 using a CPU DAI connected
to the TDM bus through the QMC and the PEF2256 needs to be seen as a
codec in order to be linked to the CPU DAI.
The codec handles the carrier detection using the PEF2256 and reports
the carrier state to the ALSA subsystem using the ASoC jack detection.

The codec, even if instantiated by the PEF2256 driver, considers the
PEF2256 as a generic framer.

The generic framer has:
 - 2 consumers (QMC HDLC drv and codec)
 - 1 provider (PEF2256)

So, the design is the following:
                        +------------------+           +---------+
                        | QMC              | <- TDM -> | PEF2256 | <-> E1
     +---------+        |  +-------------+ |           |         |
     | CPU DAI | <-data--> | QMC channel | |           |         |
     +---------+        |  +-------------+ |           |         |
+--------------+        |  +-------------+ |           |         |
| QMC HDLC drv | <-data--> | QMC channel | |           |         |
+--------------+        |  +-------------+ |           |         |
     ^                  +------------------+           |         |
     |   +--------+     +-------------+                |         |
     +-> | framer | <-> | PEF2256 drv | <- local bus ->|         |
         |        |     |             |                +---------+
     +-> |        |     |             |
     |   +--------+     |  +-------+  |
     +-------------------> | codec |  |
                        |  +-------+  |
                        +-------------+

Further more, the TDM timeslots used by the QMC HDLC driver need to be
configured at runtime (QMC dynamic timeslots).

Several weeks ago, I sent two series related to this topic:
 - Add the Lantiq PEF2256 audio support [1]
 - RFC Add support for QMC HDLC and PHY [2]
This current series is a rework of these two series taking into account
feedbacks previously received.

In order to implement all of this, I do the following:
 1) Perform some fixes (patches 1, 2)
 2) Introduce the QMC HDLC driver (patches 3, 4, 5)
 3) Add QMC dynamic timeslot support (patches 6 - 16)
 4) Add timeslots change support in QMC HDLC (patch 17)
 5) Introduce framer infrastructure (patch 18)
 6) Add PEF2256 framer provider (patches 19, 20, 21, 22, 23)
 7) Add framer codec as a framer consumer (patch 24)
 8) Add framer support as a framer consumer in QMC HDLC (patch 25, 26)

The series contains the full story and detailed modifications.
If needed, the series can be split and/or commmits can be squashed.
Let me know.

Best regards,
Hervé

[1]: https://lore.kernel.org/all/20230417171601.74656-1-herve.codina@bootlin.com/
[2]: https://lore.kernel.org/all/20230323103154.264546-1-herve.codina@bootlin.com/

Herve Codina (26):
  soc: fsl: cpm1: qmc: Fix rx channel reset
  soc: fsl: cpm1: qmc: Extend the API to provide Rx status
  dt-bindings: net: Add support for QMC HDLC
  net: wan: Add support for QMC HDLC
  MAINTAINERS: Add the Freescale QMC HDLC driver entry
  soc: fsl: cpm1: qmc: Introduce available timeslots masks
  soc: fsl: cpm1: qmc: Rename qmc_setup_tsa* to qmc_init_tsa*
  soc: fsl: cpm1: qmc: Introduce qmc_chan_setup_tsa*
  soc: fsl: cpm1: qmc: Remove no more needed checks from
    qmc_check_chans()
  soc: fsl: cpm1: qmc: Check available timeslots in qmc_check_chans()
  soc: fsl: cpm1: qmc: Add support for disabling channel TSA entries
  soc: fsl: cpm1: qmc: Split Tx and Rx TSA entries setup
  soc: fsl: cpm1: qmc: Introduce is_tsa_64rxtx flag
  soc: fsl: cpm1: qmc: Handle timeslot entries at channel start() and
    stop()
  soc: fsl: cpm1: qmc: Remove timeslots handling from setup_chan()
  soc: fsl: cpm1: qmc: Introduce functions to change timeslots at
    runtime
  wan: qmc_hdlc: Add runtime timeslots changes support
  net: wan: Add framer framework support
  dt-bindings: net: Add the Lantiq PEF2256 E1/T1/J1 framer
  mfd: core: Ensure disabled devices are skiped without aborting
  net: wan: framer: Add support for the Lantiq PEF2256 framer
  pinctrl: Add support for the Lantic PEF2256 pinmux
  MAINTAINERS: Add the Lantiq PEF2256 driver entry
  ASoC: codecs: Add support for the framer codec
  dt-bindings: net: fsl,qmc-hdlc: Add framer support
  net: wan: fsl_qmc_hdlc: Add framer support

 .../devicetree/bindings/net/fsl,qmc-hdlc.yaml |  46 +
 .../bindings/net/lantiq,pef2256.yaml          | 226 +++++
 MAINTAINERS                                   |  17 +
 drivers/mfd/mfd-core.c                        |  18 +-
 drivers/net/wan/Kconfig                       |  14 +
 drivers/net/wan/Makefile                      |   3 +
 drivers/net/wan/framer/Kconfig                |  35 +
 drivers/net/wan/framer/Makefile               |   7 +
 drivers/net/wan/framer/framer-core.c          | 935 ++++++++++++++++++
 drivers/net/wan/framer/pef2256/Makefile       |   8 +
 drivers/net/wan/framer/pef2256/pef2256-regs.h | 250 +++++
 drivers/net/wan/framer/pef2256/pef2256.c      | 880 +++++++++++++++++
 drivers/net/wan/fsl_qmc_hdlc.c                | 820 +++++++++++++++
 drivers/pinctrl/Kconfig                       |  14 +
 drivers/pinctrl/Makefile                      |   1 +
 drivers/pinctrl/pinctrl-pef2256-regs.h        |  65 ++
 drivers/pinctrl/pinctrl-pef2256.c             | 310 ++++++
 drivers/soc/fsl/qe/qmc.c                      | 467 +++++++--
 include/linux/framer/framer-provider.h        | 194 ++++
 include/linux/framer/framer.h                 | 215 ++++
 include/linux/framer/pef2256.h                |  31 +
 include/soc/fsl/qe/qmc.h                      |  25 +-
 sound/soc/codecs/Kconfig                      |  15 +
 sound/soc/codecs/Makefile                     |   2 +
 sound/soc/codecs/framer-codec.c               | 423 ++++++++
 sound/soc/fsl/fsl_qmc_audio.c                 |   2 +-
 26 files changed, 4929 insertions(+), 94 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml
 create mode 100644 Documentation/devicetree/bindings/net/lantiq,pef2256.yaml
 create mode 100644 drivers/net/wan/framer/Kconfig
 create mode 100644 drivers/net/wan/framer/Makefile
 create mode 100644 drivers/net/wan/framer/framer-core.c
 create mode 100644 drivers/net/wan/framer/pef2256/Makefile
 create mode 100644 drivers/net/wan/framer/pef2256/pef2256-regs.h
 create mode 100644 drivers/net/wan/framer/pef2256/pef2256.c
 create mode 100644 drivers/net/wan/fsl_qmc_hdlc.c
 create mode 100644 drivers/pinctrl/pinctrl-pef2256-regs.h
 create mode 100644 drivers/pinctrl/pinctrl-pef2256.c
 create mode 100644 include/linux/framer/framer-provider.h
 create mode 100644 include/linux/framer/framer.h
 create mode 100644 include/linux/framer/pef2256.h
 create mode 100644 sound/soc/codecs/framer-codec.c

On Tue, 25 Jul 2023 11:23:36 +0200 Herve Codina wrote:
> I have a system where I need to handle an HDLC interface and some audio
> data.

The new code must build cleanly with C=1 W=1, after every individual
patch.