[PATCH v5 0/3] Add SSIF BMC driver

[Quan Nguyen <quan@os.amperecomputing.com>]

This series add support the SSIF BMC driver which is to perform in-band
IPMI communication with their host in management (BMC) side.

SSIF BMC driver in this series is tested with Aspeed AST2500.

v5:
  + Correct the patches order to fix the bisect issue found by
  kernel build robot

v4:
  + Fix recursive spinlock                                      [Graeme]
  + Send response with Completion code 0xFF when aborting         [Quan]
  + Fix warning with dt_binding_check                              [Rob]
  + Change aspeed-ssif-bmc.yaml to ssif-bmc.yaml                  [Quan]
  + Added bounding check on SMBus writes and the whole request     [Dan]
  + Moved buffer to end of struct ssif_bmc_ctx to avoid context
    corruption if somehow buffer is written past the end           [Dan]
  + Return -EINVAL if userspace buffer too small, dont
    silence truncate                                       [Corey, Joel]
  + Not necessary to check NONBLOCK in lock                      [Corey]
  + Enforce one user at a time                                    [Joel]
  + Reject write with invalid response length from userspace     [Corey]
  + Add state machines for better ssif bmc state handling         [Quan]
  + Drop ssif_bmc_aspeed.c and make ssif_bmc.c is generic
    SSIF BMC driver                                               [Quan]
  + Change compatible string "aspeed,ast2500-ssif-bmc" to
    "ampere,ssif-bmc"                                             [Quan]
  + Toggle Slave enable in i2c-aspeed to turn on/off slave mode   [Ryan]
  + Added slave_enable() to struct i2c_algorithm to control
    slave mode and to address the recursive spinlock      [Graeme, Ryan]
  + Abort current request with invalid SMBus write or
    invalid command                                               [Quan]
  + Abort all request if there is pending response                [Quan]
  + Changed validate_pec() to validate_request()                  [Quan]
  + Add unsupported_smbus_cmd() to handle unknown SMBus command   [Quan]
  + Print internal state string for ease investigating issue      [Quan]
  + Move to READY state on SLAVE_STOP event                       [Quan]
  + Change initilize_transfer() to process_smbus_cmd()            [Quan]
  + Introduce functions for each slave event                      [Quan]

v3:
  + Switched binding doc to use DT schema format [Rob]
  + Splited into generic ssif_bmc and aspeed-specific [Corey, Joel]
  + Removed redundant license info [Joel]
  + Switched to use traditional if-else [Joel]
  + Removed unused ssif_bmc_ioctl() [Joel]
  + Made handle_request()/complete_response() to return void [Joel]
  + Refactored send_ssif_bmc_response()/receive_ssif_bmc_request()
  [Corey]
  + Remove mutex [Corey]
  + Use spin_lock/unlock_irqsave/restore in callback [Corey]
  + Removed the unnecessary memset [Corey]
  + Switch to use dev_err() [Corey]
  + Combine mask/unmask two interrupts together [Corey]
  + Fixed unhandled Tx done with NAK [Quan]
  + Late ack'ed Tx done w/wo Ack irq [Quan]
  + Use aspeed-specific exported aspeed_set_slave_busy() when slave busy
  to fix the deadlock [Graeme, Philipp, Quan]
  + Clean buffer for last multipart read [Quan]
  + Handle unknown incoming command [Quan]

v2:
  + Fixed compiling error with COMPILE_TEST for arc

Quan Nguyen (3):
  i2c: aspeed: Add slave_enable() to toggle slave mode
  ipmi: ssif_bmc: Add SSIF BMC driver
  bindings: ipmi: Add binding for SSIF BMC driver

 .../devicetree/bindings/ipmi/ssif-bmc.yaml    |  38 +
 drivers/char/ipmi/Kconfig                     |  11 +
 drivers/char/ipmi/Makefile                    |   1 +
 drivers/char/ipmi/ssif_bmc.c                  | 781 ++++++++++++++++++
 drivers/char/ipmi/ssif_bmc.h                  | 106 +++
 drivers/i2c/busses/i2c-aspeed.c               |  20 +
 include/linux/i2c.h                           |   2 +
 7 files changed, 959 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
 create mode 100644 drivers/char/ipmi/ssif_bmc.c
 create mode 100644 drivers/char/ipmi/ssif_bmc.h

-- 
2.28.0