[PATCH v21 0/4] Add support for mt8183 SCP.

[Pi-Hsun Shih <pihsun@chromium.org>]

Add support for controlling and communicating with mt8183's system
control processor (SCP), using the remoteproc & rpmsg framework.
And also add a cros_ec driver for CrOS EC host command over rpmsg.

The overall structure of the series is:
* remoteproc/mtk_scp.c: Control the start / stop of SCP (Patch 2).
* remoteproc/mtk_scp_ipi.c: Communicates to SCP using inter-processor
  interrupt (IPI) and shared memory (Patch 2).
* rpmsg/mtk_rpmsg.c: Wrapper to wrap the IPI communication into a rpmsg
  device. Supports name service for SCP firmware to
  announce channels (Patch 3).
* add scp dts node to mt8183 platform (Patch 4).

Changes from v20:
 - Change all public API usage of (struct platform_device *) to (struct
   mtk_scp *).
 - Rename some variables and functions to be more specific.
 - Move docs to implementation, and improve docs.
 - Address review comments.

Changes from v19:
 - Fix an incorrect include in mtk_rpmsg.h (linux/device.h ->
   linux/platform_device.h)

Changes from v18:
 - Change the way shared memory is handled, and drop patch 3.

Changes from v17:
 - Fix mixture use of __iomem found by sparse.
 - Change the ipi handler to take a u32 instead of enum scp_ipi_id.
 - Mark mtk_rpmsg_{prepare,unprepare,stop} as static.

Changes from v16:
 - Change the desc_lock mutex to be a per-id lock.
 - Put the execution of handler inside the per-id lock, to prevent race
   between scp_ipi_unregister and handler being run.
 - Move the initialization of mutex to before scp_ipi_register.

Changes from v15:
 - Fix a bug on incorrect usage of wait_event_timeout return value.

Changes from v14:
 - Fix a typo on variable in DEBUG section.

Changes from v13:
 - Move include/linux/platform_data/mtk_scp.h to
   include/linux/remoteproc/mtk_scp.h.
 - Rename scp_get_reserve_* to scp_get_reserved_*.
 - Add lock for access of scp->ipi_desc.
 - Lock the whole ipi_send function.
 - Move more setting of cache size from SCP firmware to kernel driver,
   to prevent problem while loading firmware onto DRAM.
 - Minor fixes addressing comment.

Changes from v12:
 - Initialize cache before firmware load, to avoid problem while loading
   large firmware.
 - Disable watchdog before stopping SCP, to avoid extra warning message.
 - Fix new warnings by checkpatch.

Changes from v11:
 - Fixed a bug that mtk_rpmsg_endpoint is not properly cleaned up if
   rproc_boot fails.
 - Add missing documentation in comment.

Changes from v10:
 - Drop applied cros_ec_rpmsg patches.
 - Add clock reset before loading SCP firmware.
 - Fix some type mismatch warnings when printing debug messages.

Changes from v9:
 - Remove reserve-memory-vpu_share node.
 - Remove change to cros_ec_commands.h (That is already in
   https://lore.kernel.org/lkml/20190518063949.GY4319@dell/T/)

Changes from v8:
 - Rebased onto https://patchwork.kernel.org/cover/10962385/.
 - Drop merged cros_ec_rpmsg patch, and add scp dts node patch.
 - Add more reserved memory region.

Changes from v7:
 - Rebase onto https://lore.kernel.org/patchwork/patch/1059196/.
 - Fix clock enable/disable timing for SCP driver.
 - Add more SCP IPI ID.

Changes from v6:
 - Decouple mtk_rpmsg from mtk_scp.
 - Change data of EC response to be aligned to 4 bytes.

Changes from v5:
 - Add device tree binding document for cros_ec_rpmsg.
 - Better document in comments for cros_ec_rpmsg.
 - Remove dependency on CONFIG_ in binding tree document.

Changes from v4:
 - Merge patch 6 (Load ELF firmware) into patch 2, so the driver loads
   ELF firmware by default, and no longer accept plain binary.
 - rpmsg_device listed in device tree (as a child of the SCP node) would
   have it's device tree node mapped to the rpmsg_device, so the rpmsg
   driver can use the properties on device tree.

Changes from v3:
 - Make writing to SCP SRAM aligned.
 - Add a new patch (Patch 6) to load ELF instead of bin firmware.
 - Add host event support for EC driver.
 - Fix some bugs found in testing (missing spin_lock_init,
   rproc_subdev_unprepare to rproc_subdev_stop).
 - Fix some coding style issue found by checkpatch.pl.

Changes from v2:
 - Fold patch 3 into patch 2 in v2.
 - Move IPI id around to support cross-testing for old and new firmware.
 - Finish more TODO items.

Changes from v1:
 - Extract functions and rename variables in mtk_scp.c.
 - Do cleanup properly in mtk_rpmsg.c, which also removes the problem of
   short-lived work items.
 - Code format fix based on feedback for cros_ec_rpmsg.c.
 - Extract feature detection for SCP into separate patch (Patch 6).

Eddie Huang (1):
  arm64: dts: mt8183: add scp node

Erin Lo (2):
  dt-bindings: Add a binding for Mediatek SCP
  remoteproc/mediatek: add SCP support for mt8183

Pi-Hsun Shih (1):
  rpmsg: add rpmsg support for mt8183 SCP.

 .../bindings/remoteproc/mtk,scp.txt           |  36 +
 arch/arm64/boot/dts/mediatek/mt8183-evb.dts   |  11 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      |  12 +
 drivers/remoteproc/Kconfig                    |  10 +
 drivers/remoteproc/Makefile                   |   1 +
 drivers/remoteproc/mtk_common.h               |  94 +++
 drivers/remoteproc/mtk_scp.c                  | 663 ++++++++++++++++++
 drivers/remoteproc/mtk_scp_ipi.c              | 219 ++++++
 drivers/rpmsg/Kconfig                         |   9 +
 drivers/rpmsg/Makefile                        |   1 +
 drivers/rpmsg/mtk_rpmsg.c                     | 414 +++++++++++
 include/linux/remoteproc/mtk_scp.h            |  66 ++
 include/linux/rpmsg/mtk_rpmsg.h               |  38 +
 13 files changed, 1574 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
 create mode 100644 drivers/remoteproc/mtk_common.h
 create mode 100644 drivers/remoteproc/mtk_scp.c
 create mode 100644 drivers/remoteproc/mtk_scp_ipi.c
 create mode 100644 drivers/rpmsg/mtk_rpmsg.c
 create mode 100644 include/linux/remoteproc/mtk_scp.h
 create mode 100644 include/linux/rpmsg/mtk_rpmsg.h


base-commit: fc6d6db1df2cb11bbecc542d67885742e75b4b07
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog