From mboxrd@z Thu Jan 1 00:00:00 1970 From: Quan Nguyen Date: Mon, 10 Oct 2022 08:28:24 +0700 Subject: [PATCH v10 1/3] ipmi: ssif_bmc: Add SSIF BMC driver In-Reply-To: <5fbc5a54-60f2-fc0d-a4a1-839f28a4d8ba@quicinc.com> References: <20221004093106.1653317-1-quan@os.amperecomputing.com> <20221004093106.1653317-2-quan@os.amperecomputing.com> <5fbc5a54-60f2-fc0d-a4a1-839f28a4d8ba@quicinc.com> Message-ID: <48a5e252-9a1e-65e6-e8bf-add3d39a0286@os.amperecomputing.com> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 07/10/2022 20:26, Graeme Gregory wrote: > > On 04/10/2022 10:31, Quan Nguyen wrote: >> The SMBus system interface (SSIF) IPMI BMC driver can be used to perform >> in-band IPMI communication with their host in management (BMC) side. >> >> Thanks Dan for the copy_from_user() fix in the link below. >> >> Link: >> https://lore.kernel.org/linux-arm-kernel/20220310114119.13736-4-quan at os.amperecomputing.com/ >> Signed-off-by: Quan Nguyen > > I have been testing this on our hardware and I don't seem to be able to > get this driver working. I was using an older version. > > I have hacked ssifbridged to deal with the change in len from u8 to > unsigned int. > > It works as long as I only ever send SSIF commands, any attempt to read > a response crashes the state machine and the driver never recovers. No > further SSIF comms is possible! (slave doesnt even ACK writes). > > A couple of comments below on possible state machine errors. > > Its possible I am doing something wrong! > Thanks Graeme for the test and the comments. What's your testing hardware? This was tested with Aspeed ast2500 and ast2600 with the patch series [1] below applied. If you use the same hw, could you pick the series and see if any thing improve ? [1] https://lore.kernel.org/all/20210616031046.2317-1-quan at os.amperecomputing.com/ >> --- >> v10: >> ?? + None >> >> v9: >> ?? + Fix dependence with I2C subsystem??????????????????????????? [Randy] >> ?? + Remove useless error handling path????????????????????????????? [CJ] >> ?? + Update comment for SSIF_ABORTING state????????????????????????? [CJ] >> ?? + Fix "unknown type name --u8"???????????????????? [kernel test robot] >> ?? + Fix ssif_bmc_remove() to return void to align with recent kernel >> ???? change??????????????????????????????????????????????????????? [Quan] >> >> 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 unneccessary del_timer() in response_timeout()??????? [Corey] >> ?? + Change compatible string from "ampere,ssif-bmc" to "ssif-bmc"? [Jae] >> ?? + Add MODULE_DEVICE_TABLE(of, ssif_bmc_match), fix blank line??? [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: >> ?? + None >> >> v4: >> ?? + Send response with Completion code 0xFF when aborting???????? [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] >> ?? + 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: >> ?? + 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] >> ?? + Removed mutex??????????????????????????????????????????????? [Corey] >> ?? + Use spin_lock/unlock_irqsave/restore in callback???????????? [Corey] >> ?? + Removed the unnecessary memset?????????????????????????????? [Corey] >> ?? + Switch to use dev_err()????????????????????????????????????? [Corey] >> >> v2: >> ?? + Fixed compiling error with COMPILE_TEST for arc >> --- >> ? drivers/char/ipmi/Kconfig????????? |? 10 + >> ? drivers/char/ipmi/Makefile???????? |?? 1 + >> ? drivers/char/ipmi/ssif_bmc.c?????? | 873 +++++++++++++++++++++++++++++ >> ? include/uapi/linux/ipmi_ssif_bmc.h |? 18 + >> ? 4 files changed, 902 insertions(+) >> ? create mode 100644 drivers/char/ipmi/ssif_bmc.c >> ? create mode 100644 include/uapi/linux/ipmi_ssif_bmc.h >> >> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig >> index 39565cf74b2c..b6c0d35fc1a5 100644 >> --- a/drivers/char/ipmi/Kconfig >> +++ b/drivers/char/ipmi/Kconfig >> @@ -169,6 +169,16 @@ config ASPEED_BT_IPMI_BMC >> ??????? found on Aspeed SOCs (AST2400 and AST2500). The driver >> ??????? implements the BMC side of the BT interface. >> +config SSIF_IPMI_BMC >> +??? tristate "SSIF IPMI BMC driver" >> +??? depends on I2C && I2C_SLAVE >> +??? help >> +????? This enables the IPMI SMBus system interface (SSIF) at the >> +????? management (BMC) side. >> + >> +????? The driver implements the BMC side of the SMBus system >> +????? interface (SSIF). >> + >> ? config IPMB_DEVICE_INTERFACE >> ????? tristate 'IPMB Interface handler' >> ????? depends on I2C >> diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile >> index 7ce790efad92..cb6138b8ded9 100644 >> --- a/drivers/char/ipmi/Makefile >> +++ b/drivers/char/ipmi/Makefile >> @@ -30,3 +30,4 @@ obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o >> ? obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o >> ? obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o >> ? obj-$(CONFIG_IPMB_DEVICE_INTERFACE) += ipmb_dev_int.o >> +obj-$(CONFIG_SSIF_IPMI_BMC) += ssif_bmc.o >> diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c >> new file mode 100644 >> index 000000000000..a7bb4b99000e >> --- /dev/null >> +++ b/drivers/char/ipmi/ssif_bmc.c >> @@ -0,0 +1,873 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * The driver for BMC side of SSIF interface >> + * >> + * Copyright (c) 2022, Ampere Computing LLC >> + * >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define DEVICE_NAME???????????????????????????? "ipmi-ssif-host" >> + >> +#define GET_8BIT_ADDR(addr_7bit)??????????????? (((addr_7bit) << 1) & >> 0xff) >> + >> +/* A standard SMBus Transaction is limited to 32 data bytes */ >> +#define MAX_PAYLOAD_PER_TRANSACTION???????????? 32 >> +/* Transaction includes the address, the command, the length and the >> PEC byte */ >> +#define MAX_TRANSACTION >> (MAX_PAYLOAD_PER_TRANSACTION + 4) >> + >> +#define MAX_IPMI_DATA_PER_START_TRANSACTION???? 30 >> +#define MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION??? 31 >> + >> +#define SSIF_IPMI_SINGLEPART_WRITE????????????? 0x2 >> +#define SSIF_IPMI_SINGLEPART_READ?????????????? 0x3 >> +#define SSIF_IPMI_MULTIPART_WRITE_START???????? 0x6 >> +#define SSIF_IPMI_MULTIPART_WRITE_MIDDLE??????? 0x7 >> +#define SSIF_IPMI_MULTIPART_WRITE_END?????????? 0x8 >> +#define SSIF_IPMI_MULTIPART_READ_START????????? 0x3 >> +#define SSIF_IPMI_MULTIPART_READ_MIDDLE???????? 0x9 >> + >> +/* >> + * IPMI 2.0 Spec, section 12.7 SSIF Timing, >> + * Request-to-Response Time is T6max(250ms) - T1max(20ms) - 3ms = 227ms >> + * Recover ssif_bmc from busy state if it takes up to 500ms >> + */ >> +#define RESPONSE_TIMEOUT??????????????????????? 500 /* ms */ >> + >> +struct ssif_part_buffer { >> +??? u8 address; >> +??? u8 smbus_cmd; >> +??? u8 length; >> +??? u8 payload[MAX_PAYLOAD_PER_TRANSACTION]; >> +??? u8 pec; >> +??? u8 index; >> +}; >> + >> +/* >> + * SSIF internal states: >> + *?? SSIF_READY???????? 0x00 : Ready state >> + *?? SSIF_START???????? 0x01 : Start smbus transaction >> + *?? SSIF_SMBUS_CMD???? 0x02 : Received SMBus command >> + *?? SSIF_REQ_RECVING?? 0x03 : Receiving request >> + *?? SSIF_RES_SENDING?? 0x04 : Sending response >> + *?? SSIF_ABORTING????? 0x05 : Aborting state >> + */ >> +enum ssif_state { >> +??? SSIF_READY, >> +??? SSIF_START, >> +??? SSIF_SMBUS_CMD, >> +??? SSIF_REQ_RECVING, >> +??? SSIF_RES_SENDING, >> +??? SSIF_ABORTING, >> +??? SSIF_STATE_MAX >> +}; >> + >> +struct ssif_bmc_ctx { >> +??? struct i2c_client?????? *client; >> +??? struct miscdevice?????? miscdev; >> +??? int???????????????????? msg_idx; >> +??? bool??????????????????? pec_support; >> +??? /* ssif bmc spinlock */ >> +??? spinlock_t????????????? lock; >> +??? wait_queue_head_t?????? wait_queue; >> +??? u8????????????????????? running; >> +??? enum ssif_state???????? state; >> +??? /* Timeout waiting for response */ >> +??? struct timer_list?????? response_timer; >> +??? bool??????????????????? response_timer_inited; >> +??? /* Flag to identify a Multi-part Read Transaction */ >> +??? bool??????????????????? is_singlepart_read; >> +??? u8????????????????????? nbytes_processed; >> +??? u8????????????????????? remain_len; >> +??? u8????????????????????? recv_len; >> +??? /* Block Number of a Multi-part Read Transaction */ >> +??? u8????????????????????? block_num; >> +??? bool??????????????????? request_available; >> +??? bool??????????????????? response_in_progress; >> +??? bool??????????????????? busy; >> +??? bool??????????????????? aborting; >> +??? /* Buffer for SSIF Transaction part*/ >> +??? struct ssif_part_buffer part_buf; >> +??? struct ipmi_ssif_msg??? response; >> +??? struct ipmi_ssif_msg??? request; >> +}; >> + >> +static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file) >> +{ >> +??? return container_of(file->private_data, struct ssif_bmc_ctx, >> miscdev); >> +} >> + >> +static const char *state_to_string(enum ssif_state state) >> +{ >> +??? switch (state) { >> +??? case SSIF_READY: >> +??????? return "SSIF_READY"; >> +??? case SSIF_START: >> +??????? return "SSIF_START"; >> +??? case SSIF_SMBUS_CMD: >> +??????? return "SSIF_SMBUS_CMD"; >> +??? case SSIF_REQ_RECVING: >> +??????? return "SSIF_REQ_RECVING"; >> +??? case SSIF_RES_SENDING: >> +??????? return "SSIF_RES_SENDING"; >> +??? case SSIF_ABORTING: >> +??????? return "SSIF_ABORTING"; >> +??? default: >> +??????? return "SSIF_STATE_UNKNOWN"; >> +??? } >> +} >> + >> +/* Handle SSIF message that will be sent to user */ >> +static ssize_t ssif_bmc_read(struct file *file, char __user *buf, >> size_t count, loff_t *ppos) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >> +??? struct ipmi_ssif_msg msg; >> +??? unsigned long flags; >> +??? ssize_t ret; >> + >> +??? spin_lock_irqsave(&ssif_bmc->lock, flags); >> +??? while (!ssif_bmc->request_available) { >> +??????? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> +??????? if (file->f_flags & O_NONBLOCK) >> +??????????? return -EAGAIN; >> +??????? ret = wait_event_interruptible(ssif_bmc->wait_queue, >> +?????????????????????????? ssif_bmc->request_available); >> +??????? if (ret) >> +??????????? return ret; >> +??????? spin_lock_irqsave(&ssif_bmc->lock, flags); >> +??? } >> + >> +??? if (count < min_t(ssize_t, >> +????????????? sizeof_field(struct ipmi_ssif_msg, len) + >> ssif_bmc->request.len, >> +????????????? sizeof(struct ipmi_ssif_msg))) { >> +??????? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> +??????? ret = -EINVAL; >> +??? } else { >> +??????? count = min_t(ssize_t, >> +????????????????? sizeof_field(struct ipmi_ssif_msg, len) + >> ssif_bmc->request.len, >> +????????????????? sizeof(struct ipmi_ssif_msg)); >> +??????? memcpy(&msg, &ssif_bmc->request, count); >> +??????? ssif_bmc->request_available = false; >> +??????? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> + >> +??????? ret = copy_to_user(buf, &msg, count); >> +??? } >> + >> +??? return (ret < 0) ? ret : count; >> +} >> + >> +/* Handle SSIF message that is written by user */ >> +static ssize_t ssif_bmc_write(struct file *file, const char __user >> *buf, size_t count, >> +????????????????? loff_t *ppos) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >> +??? struct ipmi_ssif_msg msg; >> +??? unsigned long flags; >> +??? ssize_t ret; >> + >> +??? if (count > sizeof(struct ipmi_ssif_msg)) >> +??????? return -EINVAL; >> + >> +??? if (copy_from_user(&msg, buf, count)) >> +??????? return -EFAULT; >> + >> +??? if (!msg.len || count < sizeof_field(struct ipmi_ssif_msg, len) + >> msg.len) >> +??????? return -EINVAL; >> + >> +??? spin_lock_irqsave(&ssif_bmc->lock, flags); >> +??? while (ssif_bmc->response_in_progress) { >> +??????? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> +??????? if (file->f_flags & O_NONBLOCK) >> +??????????? return -EAGAIN; >> +??????? ret = wait_event_interruptible(ssif_bmc->wait_queue, >> +?????????????????????????? !ssif_bmc->response_in_progress); >> +??????? if (ret) >> +??????????? return ret; >> +??????? spin_lock_irqsave(&ssif_bmc->lock, flags); >> +??? } >> + >> +??? /* >> +???? * The write must complete before the response timeout fired, >> otherwise >> +???? * the response is aborted and wait for next request >> +???? * Return -EINVAL if the response is aborted >> +???? */ >> +??? ret = (ssif_bmc->response_timer_inited) ? 0 : -EINVAL; >> +??? if (ret) >> +??????? goto exit; >> + >> +??? del_timer(&ssif_bmc->response_timer); >> +??? ssif_bmc->response_timer_inited = false; >> + >> +??? memcpy(&ssif_bmc->response, &msg, count); >> +??? ssif_bmc->is_singlepart_read = (msg.len <= >> MAX_PAYLOAD_PER_TRANSACTION); >> + >> +??? ssif_bmc->response_in_progress = true; >> + >> +??? /* ssif_bmc not busy */ >> +??? ssif_bmc->busy = false; >> + >> +??? /* Clean old request buffer */ >> +??? memset(&ssif_bmc->request, 0, sizeof(struct ipmi_ssif_msg)); >> +exit: >> +??? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> + >> +??? return (ret < 0) ? ret : count; >> +} >> + >> +static int ssif_bmc_open(struct inode *inode, struct file *file) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >> +??? int ret = 0; >> + >> +??? spin_lock_irq(&ssif_bmc->lock); >> +??? if (!ssif_bmc->running) >> +??????? ssif_bmc->running = 1; >> +??? else >> +??????? ret = -EBUSY; >> +??? spin_unlock_irq(&ssif_bmc->lock); >> + >> +??? return ret; >> +} >> + >> +static __poll_t ssif_bmc_poll(struct file *file, poll_table *wait) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >> +??? __poll_t mask = 0; >> + >> +??? poll_wait(file, &ssif_bmc->wait_queue, wait); >> + >> +??? spin_lock_irq(&ssif_bmc->lock); >> +??? /* The request is available, userspace application can get the >> request */ >> +??? if (ssif_bmc->request_available) >> +??????? mask |= POLLIN; >> + >> +??? spin_unlock_irq(&ssif_bmc->lock); >> + >> +??? return mask; >> +} >> + >> +static int ssif_bmc_release(struct inode *inode, struct file *file) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >> + >> +??? spin_lock_irq(&ssif_bmc->lock); >> +??? ssif_bmc->running = 0; >> +??? spin_unlock_irq(&ssif_bmc->lock); >> + >> +??? return 0; >> +} >> + >> +/* >> + * System calls to device interface for user apps >> + */ >> +static const struct file_operations ssif_bmc_fops = { >> +??? .owner??????? = THIS_MODULE, >> +??? .open??????? = ssif_bmc_open, >> +??? .read??????? = ssif_bmc_read, >> +??? .write??????? = ssif_bmc_write, >> +??? .release??? = ssif_bmc_release, >> +??? .poll??????? = ssif_bmc_poll, >> +}; >> + >> +/* Called with ssif_bmc->lock held. */ >> +static void complete_response(struct ssif_bmc_ctx *ssif_bmc) >> +{ >> +??? /* Invalidate response in buffer to denote it having been sent. */ >> +??? ssif_bmc->response.len = 0; >> +??? ssif_bmc->response_in_progress = false; >> +??? ssif_bmc->nbytes_processed = 0; >> +??? ssif_bmc->remain_len = 0; >> +??? ssif_bmc->busy = false; >> +??? memset(&ssif_bmc->part_buf, 0, sizeof(struct ssif_part_buffer)); >> +??? wake_up_all(&ssif_bmc->wait_queue); >> +} >> + >> +static void response_timeout(struct timer_list *t) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = from_timer(ssif_bmc, t, >> response_timer); >> +??? unsigned long flags; >> + >> +??? spin_lock_irqsave(&ssif_bmc->lock, flags); >> + >> +??? /* Do nothing if the response is in progress */ >> +??? if (!ssif_bmc->response_in_progress) { >> +??????? /* Recover ssif_bmc from busy */ >> +??????? ssif_bmc->busy = false; >> +??????? ssif_bmc->response_timer_inited = false; >> +??????? /* Set aborting flag */ >> +??????? ssif_bmc->aborting = true; >> +??? } >> + >> +??? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> +} >> + >> +/* Called with ssif_bmc->lock held. */ >> +static void handle_request(struct ssif_bmc_ctx *ssif_bmc) >> +{ >> +??? /* set ssif_bmc to busy waiting for response */ >> +??? ssif_bmc->busy = true; >> +??? /* Request message is available to process */ >> +??? ssif_bmc->request_available = true; >> +??? /* Clean old response buffer */ >> +??? memset(&ssif_bmc->response, 0, sizeof(struct ipmi_ssif_msg)); >> +??? /* This is the new READ request.*/ >> +??? wake_up_all(&ssif_bmc->wait_queue); >> + >> +??? /* Armed timer to recover slave from busy state in case of no >> response */ >> +??? if (!ssif_bmc->response_timer_inited) { >> +??????? timer_setup(&ssif_bmc->response_timer, response_timeout, 0); >> +??????? ssif_bmc->response_timer_inited = true; >> +??? } >> +??? mod_timer(&ssif_bmc->response_timer, jiffies + >> msecs_to_jiffies(RESPONSE_TIMEOUT)); >> +} >> + >> +static void calculate_response_part_pec(struct ssif_part_buffer *part) >> +{ >> +??? u8 addr = part->address; >> + >> +??? /* PEC - Start Read Address */ >> +??? part->pec = i2c_smbus_pec(0, &addr, 1); >> +??? /* PEC - SSIF Command */ >> +??? part->pec = i2c_smbus_pec(part->pec, &part->smbus_cmd, 1); >> +??? /* PEC - Restart Write Address */ >> +??? addr = addr | 0x01; >> +??? part->pec = i2c_smbus_pec(part->pec, &addr, 1); >> +??? part->pec = i2c_smbus_pec(part->pec, &part->length, 1); >> +??? if (part->length) >> +??????? part->pec = i2c_smbus_pec(part->pec, part->payload, >> part->length); >> +} >> + >> +static void set_singlepart_response_buffer(struct ssif_bmc_ctx >> *ssif_bmc) >> +{ >> +??? struct ssif_part_buffer *part = &ssif_bmc->part_buf; >> + >> +??? part->address = GET_8BIT_ADDR(ssif_bmc->client->addr); >> +??? part->length = (u8)ssif_bmc->response.len; >> + >> +??? /* Clear the rest to 0 */ >> +??? memset(part->payload + part->length, 0, >> MAX_PAYLOAD_PER_TRANSACTION - part->length); >> +??? memcpy(&part->payload[0], &ssif_bmc->response.payload[0], >> part->length); >> +} >> + >> +static void set_multipart_response_buffer(struct ssif_bmc_ctx *ssif_bmc) >> +{ >> +??? struct ssif_part_buffer *part = &ssif_bmc->part_buf; >> +??? u8 part_len = 0; >> + >> +??? part->address = GET_8BIT_ADDR(ssif_bmc->client->addr); >> +??? switch (part->smbus_cmd) { >> +??? case SSIF_IPMI_MULTIPART_READ_START: >> +??????? /* >> +???????? * Read Start length is 32 bytes. >> +???????? * Read Start transfer first 30 bytes of IPMI response >> +???????? * and 2 special code 0x00, 0x01. >> +???????? */ >> +??????? ssif_bmc->nbytes_processed = 0; >> +??????? ssif_bmc->block_num = 0; >> +??????? part->length = MAX_PAYLOAD_PER_TRANSACTION; >> +??????? part_len = MAX_IPMI_DATA_PER_START_TRANSACTION; >> +??????? ssif_bmc->remain_len = ssif_bmc->response.len - part_len; >> + >> +??????? part->payload[0] = 0x00; /* Start Flag */ >> +??????? part->payload[1] = 0x01; /* Start Flag */ >> + >> +??????? memcpy(&part->payload[2], &ssif_bmc->response.payload[0], >> part_len); >> +??????? break; >> + >> +??? case SSIF_IPMI_MULTIPART_READ_MIDDLE: >> +??????? /* >> +???????? * IPMI READ Middle or READ End messages can carry up to 31 >> bytes >> +???????? * IPMI data plus block number byte. >> +???????? */ >> +??????? if (ssif_bmc->remain_len <= >> MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION) { >> +??????????? /* >> +???????????? * This is READ End message >> +???????????? *? Return length is the remaining response data length >> +???????????? *? plus block number >> +???????????? *? Block number 0xFF is to indicate this is last message >> +???????????? * >> +???????????? */ >> +??????????? /* Clean the buffer */ >> +??????????? memset(&part->payload[0], 0, MAX_PAYLOAD_PER_TRANSACTION); >> +??????????? part->length = ssif_bmc->remain_len + 1; >> +??????????? part_len = ssif_bmc->remain_len; >> +??????????? ssif_bmc->block_num = 0xFF; >> +??????????? part->payload[0] = ssif_bmc->block_num; >> +??????? } else { >> +??????????? /* >> +???????????? * This is READ Middle message >> +???????????? *? Response length is the maximum SMBUS transfer length >> +???????????? *? Block number byte is incremented >> +???????????? * Return length is maximum SMBUS transfer length >> +???????????? */ >> +??????????? part->length = MAX_PAYLOAD_PER_TRANSACTION; >> +??????????? part_len = MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION; >> +??????????? part->payload[0] = ssif_bmc->block_num; >> +??????????? ssif_bmc->block_num++; >> +??????? } >> + >> +??????? ssif_bmc->remain_len -= part_len; >> +??????? memcpy(&part->payload[1], ssif_bmc->response.payload + >> ssif_bmc->nbytes_processed, >> +?????????????? part_len); >> +??????? break; >> + >> +??? default: >> +??????? /* Do not expect to go to this case */ >> +??????? dev_err(&ssif_bmc->client->dev, "%s: Unexpected SMBus command >> 0x%x\n", >> +??????????? __func__, part->smbus_cmd); >> +??????? break; >> +??? } >> + >> +??? ssif_bmc->nbytes_processed += part_len; >> +} >> + >> +static bool supported_read_cmd(u8 cmd) >> +{ >> +??? if (cmd == SSIF_IPMI_SINGLEPART_READ || >> +??????? cmd == SSIF_IPMI_MULTIPART_READ_START || >> +??????? cmd == SSIF_IPMI_MULTIPART_READ_MIDDLE) >> +??????? return true; >> + >> +??? return false; >> +} >> + >> +static bool supported_write_cmd(u8 cmd) >> +{ >> +??? if (cmd == SSIF_IPMI_SINGLEPART_WRITE || >> +??????? cmd == SSIF_IPMI_MULTIPART_WRITE_START || >> +??????? cmd == SSIF_IPMI_MULTIPART_WRITE_MIDDLE || >> +??????? cmd == SSIF_IPMI_MULTIPART_WRITE_END) >> +??????? return true; >> + >> +??? return false; >> +} >> + >> +/* Process the IPMI response that will be read by master */ >> +static void handle_read_processed(struct ssif_bmc_ctx *ssif_bmc, u8 >> *val) >> +{ >> +??? struct ssif_part_buffer *part = &ssif_bmc->part_buf; >> + >> +??? /* msg_idx start from 0 */ >> +??? if (part->index < part->length) >> +??????? *val = part->payload[part->index]; >> +??? else if (part->index == part->length && ssif_bmc->pec_support) >> +??????? *val = part->pec; >> +??? else >> +??????? *val = 0; >> + >> +??? part->index++; >> +} >> + >> +static void handle_write_received(struct ssif_bmc_ctx *ssif_bmc, u8 >> *val) >> +{ >> +??? /* >> +???? * The msg_idx must be 1 when first enter SSIF_REQ_RECVING state >> +???? * And it would never exceeded 36 bytes included the 32 bytes max >> payload + >> +???? * the address + the command + the len and the PEC. >> +???? */ >> +??? if (ssif_bmc->msg_idx < 1? || ssif_bmc->msg_idx > MAX_TRANSACTION) >> +??????? return; >> + >> +??? if (ssif_bmc->msg_idx == 1) { >> +??????? ssif_bmc->part_buf.length = *val; >> +??????? ssif_bmc->part_buf.index = 0; >> +??? } else { >> +??????? ssif_bmc->part_buf.payload[ssif_bmc->part_buf.index++] = *val; >> +??? } >> + >> +??? ssif_bmc->msg_idx++; >> +} >> + >> +static bool validate_request_part(struct ssif_bmc_ctx *ssif_bmc) >> +{ >> +??? struct ssif_part_buffer *part = &ssif_bmc->part_buf; >> +??? bool ret = true; >> +??? u8 cpec; >> +??? u8 addr; >> + >> +??? if (part->index == part->length) { >> +??????? /* PEC is not included */ >> +??????? ssif_bmc->pec_support = false; >> +??????? ret = true; >> +??????? goto exit; >> +??? } >> + >> +??? if (part->index != part->length + 1) { >> +??????? ret = false; >> +??????? goto exit; >> +??? } >> + >> +??? /* PEC is included */ >> +??? ssif_bmc->pec_support = true; >> +??? part->pec = part->payload[part->length]; >> +??? addr = GET_8BIT_ADDR(ssif_bmc->client->addr); >> +??? cpec = i2c_smbus_pec(0, &addr, 1); >> +??? cpec = i2c_smbus_pec(cpec, &part->smbus_cmd, 1); >> +??? cpec = i2c_smbus_pec(cpec, &part->length, 1); >> +??? /* >> +???? * As SMBus specification does not allow the length >> +???? * (byte count) in the Write-Block protocol to be zero. >> +???? * Therefore, it is illegal to have the last Middle >> +???? * transaction in the sequence carry 32-byte and have >> +???? * a length of ?0? in the End transaction. >> +???? * But some users may try to use this way and we should >> +???? * prevent ssif_bmc driver broken in this case. >> +???? */ >> +??? if (part->length) >> +??????? cpec = i2c_smbus_pec(cpec, part->payload, part->length); >> + >> +??? if (cpec != part->pec) >> +??????? ret = false; >> + >> +exit: >> +??? return ret; >> +} >> + >> +static void process_request_part(struct ssif_bmc_ctx *ssif_bmc) >> +{ >> +??? struct ssif_part_buffer *part = &ssif_bmc->part_buf; >> +??? unsigned int len; >> + >> +??? switch (part->smbus_cmd) { >> +??? case SSIF_IPMI_SINGLEPART_WRITE: >> +??????? /* save the whole part to request*/ >> +??????? ssif_bmc->request.len = part->length; >> +??????? memcpy(ssif_bmc->request.payload, part->payload, part->length); >> + >> +??????? break; >> +??? case SSIF_IPMI_MULTIPART_WRITE_START: >> +??????? ssif_bmc->request.len = 0; >> + >> +??????? fallthrough; >> +??? case SSIF_IPMI_MULTIPART_WRITE_MIDDLE: >> +??? case SSIF_IPMI_MULTIPART_WRITE_END: >> +??????? len = ssif_bmc->request.len + part->length; >> +??????? /* Do the bound check here, not allow the request len exceed >> 254 bytes */ >> +??????? if (len > IPMI_SSIF_PAYLOAD_MAX) { >> +??????????? dev_warn(&ssif_bmc->client->dev, >> +???????????????? "Warn: Request exceeded 254 bytes, aborting"); >> +??????????? /* Request too long, aborting */ >> +??????????? ssif_bmc->aborting =? true; >> +??????? } else { >> +??????????? memcpy(ssif_bmc->request.payload + ssif_bmc->request.len, >> +?????????????????? part->payload, part->length); >> +??????????? ssif_bmc->request.len += part->length; >> +??????? } >> +??????? break; >> +??? default: >> +??????? /* Do not expect to go to this case */ >> +??????? dev_err(&ssif_bmc->client->dev, "%s: Unexpected SMBus command >> 0x%x\n", >> +??????????? __func__, part->smbus_cmd); >> +??????? break; >> +??? } >> +} >> + >> +static void process_smbus_cmd(struct ssif_bmc_ctx *ssif_bmc, u8 *val) >> +{ >> +??? /* SMBUS command can vary (single or multi-part) */ >> +??? ssif_bmc->part_buf.smbus_cmd = *val; >> +??? ssif_bmc->msg_idx = 1; >> +??? memset(&ssif_bmc->part_buf.payload[0], 0, >> MAX_PAYLOAD_PER_TRANSACTION); >> + >> +??? if (*val == SSIF_IPMI_SINGLEPART_WRITE || *val == >> SSIF_IPMI_MULTIPART_WRITE_START) { >> +??????? /* >> +???????? * The response maybe not come in-time, causing host SSIF driver >> +???????? * to timeout and resend a new request. In such case check for >> +???????? * pending response and clear it >> +???????? */ >> +??????? if (ssif_bmc->response_in_progress) >> +??????????? complete_response(ssif_bmc); >> + >> +??????? /* This is new request, flip aborting flag if set */ >> +??????? if (ssif_bmc->aborting) >> +??????????? ssif_bmc->aborting = false; >> +??? } >> +} >> + >> +static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 >> *val) >> +{ >> +??? if (ssif_bmc->state == SSIF_READY || > Is this actually correct? The state machine seems to set this as the > default state and in my testing we seem to always reach here with the > state == SSIF_READY? The I2C_SLAVE_READ_REQUESTED event is expected to come on SSIF_SMBUS_CMD state where Slave has already received and validated the SMBus command, in this case is the I2C_SLAVE_READ_REQUESTED event if the SMBus command indeed is the READ command. You can see the check supported_read_cmd() below. If Slave see the I2C_SLAVE_READ_REQUESTED event on other states, it will transition to SSIF_ABORTING state that discard everything until there is a new transaction come. On READ, the sequence of Slave event should be as below: I2C_SLAVE_WRITE_REQUESTED (addr) => I2C_SLAVE_WRITE_RECEIVED (SMBus cmd) => I2C_SLAVE_READ_REQUESTED (Slave feed the first byte) => I2C_SLAVE_READ_PROCESSED (Slave 2nd byte) => .... => I2C_SLAVE_STOP >> +??????? ssif_bmc->state == SSIF_START || >> +??????? ssif_bmc->state == SSIF_REQ_RECVING || >> +??????? ssif_bmc->state == SSIF_RES_SENDING) { >> +??????? dev_warn(&ssif_bmc->client->dev, >> +???????????? "Warn: %s unexpected READ REQUESTED in state=%s\n", >> +???????????? __func__, state_to_string(ssif_bmc->state)); >> +??????? ssif_bmc->state = SSIF_ABORTING; >> +??????? *val = 0; >> +??????? return; >> + >> +??? } else if (ssif_bmc->state == SSIF_SMBUS_CMD) { >> +??????? if (!supported_read_cmd(ssif_bmc->part_buf.smbus_cmd)) { >> +??????????? dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus >> read command=0x%x", >> +???????????????? ssif_bmc->part_buf.smbus_cmd); >> +??????????? ssif_bmc->aborting = true; >> +??????? } >> + >> +??????? if (ssif_bmc->aborting) >> +??????????? ssif_bmc->state = SSIF_ABORTING; >> +??????? else >> +??????????? ssif_bmc->state = SSIF_RES_SENDING; >> +??? } >> + >> +??? ssif_bmc->msg_idx = 0; >> + >> +??? /* Send 0 if there is nothing to send */ >> +??? if (!ssif_bmc->response_in_progress || ssif_bmc->state == >> SSIF_ABORTING) { >> +??????? *val = 0; >> +??????? return; >> +??? } >> + >> +??? if (ssif_bmc->is_singlepart_read) >> +??????? set_singlepart_response_buffer(ssif_bmc); >> +??? else >> +??????? set_multipart_response_buffer(ssif_bmc); >> + >> +??? calculate_response_part_pec(&ssif_bmc->part_buf); >> +??? ssif_bmc->part_buf.index = 0; >> +??? *val = ssif_bmc->part_buf.length; >> +} >> + >> +static void on_read_processed_event(struct ssif_bmc_ctx *ssif_bmc, u8 >> *val) >> +{ >> +??? if (ssif_bmc->state == SSIF_READY || > Same comment as above? Same here, I2C_SLAVE_READ_PROCESSED is expected to come after the I2C_SLAVE_READ_REQUESTED or other I2C_SLAVE_READ_PROCESSED. ie: when the state is SSIF_RES_SENDING. If it comes when Slave in states other than SSIF_RES_SENDING, the Slave will transition to SSIF_ABORTING state. >> +??????? ssif_bmc->state == SSIF_START || >> +??????? ssif_bmc->state == SSIF_REQ_RECVING || >> +??????? ssif_bmc->state == SSIF_SMBUS_CMD) { >> +??????? dev_warn(&ssif_bmc->client->dev, >> +???????????? "Warn: %s unexpected READ PROCESSED in state=%s\n", >> +???????????? __func__, state_to_string(ssif_bmc->state)); >> +??????? ssif_bmc->state = SSIF_ABORTING; >> +??????? *val = 0; >> +??????? return; >> +??? } >> + >> +??? /* Send 0 if there is nothing to send */ >> +??? if (!ssif_bmc->response_in_progress || ssif_bmc->state == >> SSIF_ABORTING) { >> +??????? *val = 0; >> +??????? return; >> +??? } >> + >> +??? handle_read_processed(ssif_bmc, val); >> +} >> + >> +static void on_write_requested_event(struct ssif_bmc_ctx *ssif_bmc, >> u8 *val) >> +{ >> +??? if (ssif_bmc->state == SSIF_READY || ssif_bmc->state == >> SSIF_SMBUS_CMD) { >> +??????? ssif_bmc->state = SSIF_START; >> + >> +??? } else if (ssif_bmc->state == SSIF_START || >> +?????????? ssif_bmc->state == SSIF_REQ_RECVING || >> +?????????? ssif_bmc->state == SSIF_RES_SENDING) { >> +??????? dev_warn(&ssif_bmc->client->dev, >> +???????????? "Warn: %s unexpected WRITE REQUEST in state=%s\n", >> +???????????? __func__, state_to_string(ssif_bmc->state)); >> +??????? ssif_bmc->state = SSIF_ABORTING; >> +??????? return; >> +??? } >> + >> +??? ssif_bmc->msg_idx = 0; >> +??? ssif_bmc->part_buf.address = *val; >> +} >> + >> +static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, u8 >> *val) >> +{ >> +??? if (ssif_bmc->state == SSIF_READY || >> +??????? ssif_bmc->state == SSIF_RES_SENDING) { >> +??????? dev_warn(&ssif_bmc->client->dev, >> +???????????? "Warn: %s unexpected WRITE RECEIVED in state=%s\n", >> +???????????? __func__, state_to_string(ssif_bmc->state)); >> +??????? ssif_bmc->state = SSIF_ABORTING; >> + >> +??? } else if (ssif_bmc->state == SSIF_START) { >> +??????? ssif_bmc->state = SSIF_SMBUS_CMD; >> + >> +??? } else if (ssif_bmc->state == SSIF_SMBUS_CMD) { >> +??????? if (!supported_write_cmd(ssif_bmc->part_buf.smbus_cmd)) { >> +??????????? dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus >> write command=0x%x", >> +???????????????? ssif_bmc->part_buf.smbus_cmd); >> +??????????? ssif_bmc->aborting = true; >> +??????? } >> + >> +??????? if (ssif_bmc->aborting) >> +??????????? ssif_bmc->state = SSIF_ABORTING; >> +??????? else >> +??????????? ssif_bmc->state = SSIF_REQ_RECVING; >> +??? } >> + >> +??? /* This is response sending state */ >> +??? if (ssif_bmc->state == SSIF_REQ_RECVING) >> +??????? handle_write_received(ssif_bmc, val); >> +??? else if (ssif_bmc->state == SSIF_SMBUS_CMD) >> +??????? process_smbus_cmd(ssif_bmc, val); >> +} >> + >> +static void on_stop_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val) >> +{ >> +??? if (ssif_bmc->state == SSIF_READY || >> +??????? ssif_bmc->state == SSIF_START || >> +??????? ssif_bmc->state == SSIF_SMBUS_CMD || >> +??????? ssif_bmc->state == SSIF_ABORTING) { >> +??????? dev_warn(&ssif_bmc->client->dev, >> +???????????? "Warn: %s unexpected SLAVE STOP in state=%s\n", >> +???????????? __func__, state_to_string(ssif_bmc->state)); >> +??????? ssif_bmc->state = SSIF_READY; >> + >> +??? } else if (ssif_bmc->state == SSIF_REQ_RECVING) { >> +??????? if (validate_request_part(ssif_bmc)) { >> +??????????? process_request_part(ssif_bmc); >> +??????????? if (ssif_bmc->part_buf.smbus_cmd == >> SSIF_IPMI_SINGLEPART_WRITE || >> +??????????????? ssif_bmc->part_buf.smbus_cmd == >> SSIF_IPMI_MULTIPART_WRITE_END) >> +??????????????? handle_request(ssif_bmc); >> +??????????? ssif_bmc->state = SSIF_READY; >> +??????? } else { >> +??????????? /* >> +???????????? * A BMC that receives an invalid request drop the data >> for the write >> +???????????? * transaction and any further transactions (read or >> write) until >> +???????????? * the next valid read or write Start transaction is >> received >> +???????????? */ >> +??????????? dev_err(&ssif_bmc->client->dev, "Error: invalid pec\n"); >> +??????????? ssif_bmc->aborting = true; >> +??????? } >> +??? } else if (ssif_bmc->state == SSIF_RES_SENDING) { >> +??????? if (ssif_bmc->is_singlepart_read || ssif_bmc->block_num == 0xFF) >> +??????????? /* Invalidate response buffer to denote it is sent */ >> +??????????? complete_response(ssif_bmc); >> +??????? ssif_bmc->state = SSIF_READY; >> +??? } >> + >> +??? /* Reset message index */ >> +??? ssif_bmc->msg_idx = 0; >> +} >> + >> +/* >> + * Callback function to handle I2C slave events >> + */ >> +static int ssif_bmc_cb(struct i2c_client *client, enum >> i2c_slave_event event, u8 *val) >> +{ >> +??? unsigned long flags; >> +??? struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client); >> +??? int ret = 0; >> + >> +??? spin_lock_irqsave(&ssif_bmc->lock, flags); >> + >> +??? switch (event) { >> +??? case I2C_SLAVE_READ_REQUESTED: >> +??????? on_read_requested_event(ssif_bmc, val); >> +??????? break; >> + >> +??? case : >> +??????? on_write_requested_event(ssif_bmc, val); >> +??????? break; >> + >> +??? case I2C_SLAVE_READ_PROCESSED: >> +??????? on_read_processed_event(ssif_bmc, val); >> +??????? break; >> + >> +??? case I2C_SLAVE_WRITE_RECEIVED: >> +??????? on_write_received_event(ssif_bmc, val); >> +??????? break; >> + >> +??? case I2C_SLAVE_STOP: >> +??????? on_stop_event(ssif_bmc, val); >> +??????? break; >> + >> +??? default: >> +??????? dev_warn(&ssif_bmc->client->dev, "Warn: Unknown i2c slave >> event\n"); >> +??????? break; >> +??? } >> + >> +??? if (!ssif_bmc->aborting && ssif_bmc->busy) >> +??????? ret = -EBUSY; >> + >> +??? spin_unlock_irqrestore(&ssif_bmc->lock, flags); >> + >> +??? return ret; >> +} >> + >> +static int ssif_bmc_probe(struct i2c_client *client, const struct >> i2c_device_id *id) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc; >> +??? int ret; >> + >> +??? ssif_bmc = devm_kzalloc(&client->dev, sizeof(*ssif_bmc), >> GFP_KERNEL); >> +??? if (!ssif_bmc) >> +??????? return -ENOMEM; >> + >> +??? spin_lock_init(&ssif_bmc->lock); >> + >> +??? init_waitqueue_head(&ssif_bmc->wait_queue); >> +??? ssif_bmc->request_available = false; >> +??? ssif_bmc->response_in_progress = false; >> +??? ssif_bmc->busy = false; >> +??? ssif_bmc->response_timer_inited = false; >> + >> +??? /* Register misc device interface */ >> +??? ssif_bmc->miscdev.minor = MISC_DYNAMIC_MINOR; >> +??? ssif_bmc->miscdev.name = DEVICE_NAME; >> +??? ssif_bmc->miscdev.fops = &ssif_bmc_fops; >> +??? ssif_bmc->miscdev.parent = &client->dev; >> +??? ret = misc_register(&ssif_bmc->miscdev); >> +??? if (ret) >> +??????? return ret; >> + >> +??? ssif_bmc->client = client; >> +??? ssif_bmc->client->flags |= I2C_CLIENT_SLAVE; >> + >> +??? /* Register I2C slave */ >> +??? i2c_set_clientdata(client, ssif_bmc); >> +??? ret = i2c_slave_register(client, ssif_bmc_cb); >> +??? if (ret) >> +??????? misc_deregister(&ssif_bmc->miscdev); >> + >> +??? return ret; >> +} >> + >> +static void ssif_bmc_remove(struct i2c_client *client) >> +{ >> +??? struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client); >> + >> +??? i2c_slave_unregister(client); >> +??? misc_deregister(&ssif_bmc->miscdev); >> +} >> + >> +static const struct of_device_id ssif_bmc_match[] = { >> +??? { .compatible = "ssif-bmc" }, >> +??? { }, >> +}; >> +MODULE_DEVICE_TABLE(of, ssif_bmc_match); >> + >> +static const struct i2c_device_id ssif_bmc_id[] = { >> +??? { DEVICE_NAME, 0 }, >> +??? { }, >> +}; >> +MODULE_DEVICE_TABLE(i2c, ssif_bmc_id); >> + >> +static struct i2c_driver ssif_bmc_driver = { >> +??? .driver???????? = { >> +??????? .name?????????? = DEVICE_NAME, >> +??????? .of_match_table = ssif_bmc_match, >> +??? }, >> +??? .probe????????? = ssif_bmc_probe, >> +??? .remove???????? = ssif_bmc_remove, >> +??? .id_table?????? = ssif_bmc_id, >> +}; >> + >> +module_i2c_driver(ssif_bmc_driver); >> + >> +MODULE_AUTHOR("Quan Nguyen "); >> +MODULE_AUTHOR("Chuong Tran "); >> +MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF >> interface."); >> +MODULE_LICENSE("GPL"); >> diff --git a/include/uapi/linux/ipmi_ssif_bmc.h >> b/include/uapi/linux/ipmi_ssif_bmc.h >> new file mode 100644 >> index 000000000000..1c6a753dad08 >> --- /dev/null >> +++ b/include/uapi/linux/ipmi_ssif_bmc.h >> @@ -0,0 +1,18 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note*/ >> +/* >> + * Copyright (c) 2022, Ampere Computing LLC. >> + */ >> + >> +#ifndef _UAPI_LINUX_IPMI_SSIF_BMC_H >> +#define _UAPI_LINUX_IPMI_SSIF_BMC_H >> + >> +#include >> + >> +/* Max length of ipmi ssif message included netfn and cmd field */ >> +#define IPMI_SSIF_PAYLOAD_MAX???????? 254 >> +struct ipmi_ssif_msg { >> +??? unsigned int len; >> +??? __u8??? payload[IPMI_SSIF_PAYLOAD_MAX]; >> +}; >> + >> +#endif /* _UAPI_LINUX_IPMI_SSIF_BMC_H */