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. Discussion for v7: https://lkml.org/lkml/2022/4/22/4 v8: + Dropped ssif_bmc.h file and move its content to ssif_bmc.c [Corey] + Add struct ipmi_ssif_msg to include/uapi/linux/ipmi_ssif_bmc.h header file [Corey] + Use unsigned int for len field in struct ipmi_ssif_msg [Corey] + Avoid using packed structure [Corey] + Add comment to clarify the logic flow [Corey] + Fix multipart read end with len=0 issue [Corey] + Refactor code handle the too big request message [Corey] + Fix code indentation issue [Corey] + Clean buffer before receiving request to avoid garbage [Quan] + Fix the license to SPDX-License-Identifier: GPL-2.0-only [Quan] v7: + Remove unnecessary del_timer() in response_timeout() [Corey] + Change compatible string from "ampere,ssif-bmc" to "ssif-bmc" [Jae] + Dropped the use of ssif_msg_len() macro, use the len directly [Quan] + Solve possible issue if both response timer and ssif_bmc_write() occurred at the same time [Corey] + Fix wrong return type of ssif_bmc_poll() [kernel robot test] + Refactor and introduce ssif_part_buffer struct to replace the response_buf to manage each send/receive part of ssif [Quan] + Change SSIF_BAD_SMBUS state to SSIF_ABORTING state [Corey] + Support abort feature to skip the current bad request/response and wait until next new request [Corey] + Refactor the PEC calculation to avoid the re-calculate the PEC on each I2C_SLAVE_WRITE_RECEIVED event [Quan] + Fix the use of error-proned idx [Corey] + Defer the test for valid SMBus command until the read/write part is determined [Quan] + Change/split unsupported_smbus_cmd() to supported_[write|read]_cmd() [Corey] + Abort the request if somehow its size exceeded 255 bytes [Quan] v6: + Drop the use of slave_enable() [Wolfram] + Make i2c-aspeed to issue RxCmdLast command on all I2C_SLAVE_WRITE_REQUESTED event to assert NAK when slave busy [Quan] + Make i2c slave to return -EBUSY when it's busy [Quan] + Drop the aborting feature as return Completion Code 0xFF may stop host to retry and make ipmi_ssif.so fails to load [Quan] + Add timer to recover slave from busy state when no response [Quan] + Clean request/response buffer appropriately [Quan] + Add some minor change on error and warning messages [Quan] 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, don't 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() and 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): ipmi: ssif_bmc: Add SSIF BMC driver bindings: ipmi: Add binding for SSIF BMC driver i2c: aspeed: Assert NAK when slave is busy .../devicetree/bindings/ipmi/ssif-bmc.yaml | 38 + drivers/char/ipmi/Kconfig | 11 + drivers/char/ipmi/Makefile | 1 + drivers/char/ipmi/ssif_bmc.c | 880 ++++++++++++++++++ drivers/i2c/busses/i2c-aspeed.c | 5 +- include/uapi/linux/ipmi_ssif_bmc.h | 16 + 6 files changed, 950 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml create mode 100644 drivers/char/ipmi/ssif_bmc.c create mode 100644 include/uapi/linux/ipmi_ssif_bmc.h -- 2.35.1
