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 v5: https://lkml.org/lkml/2021/7/13/868 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, 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() 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 Dan Carpenter (1): ipmi: ssif_bmc: Return -EFAULT if copy_from_user() fails 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 | 790 ++++++++++++++++++ drivers/char/ipmi/ssif_bmc.h | 102 +++ drivers/i2c/busses/i2c-aspeed.c | 5 +- 6 files changed, 946 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 drivers/char/ipmi/ssif_bmc.h -- 2.35.1
