The SMBus system interface (SSIF) IPMI BMC driver can be used to perform in-band IPMI communication with their host in management (BMC) side. This commits adds support specifically for Aspeed AST2500 which commonly used as Board Management Controllers. Signed-off-by: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx> --- drivers/char/ipmi/Kconfig | 22 + drivers/char/ipmi/Makefile | 2 + drivers/char/ipmi/ssif_bmc.c | 645 ++++++++++++++++++++++++++++ drivers/char/ipmi/ssif_bmc.h | 92 ++++ drivers/char/ipmi/ssif_bmc_aspeed.c | 132 ++++++ 5 files changed, 893 insertions(+) create mode 100644 drivers/char/ipmi/ssif_bmc.c create mode 100644 drivers/char/ipmi/ssif_bmc.h create mode 100644 drivers/char/ipmi/ssif_bmc_aspeed.c diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig index 07847d9a459a..d67fd204409a 100644 --- a/drivers/char/ipmi/Kconfig +++ b/drivers/char/ipmi/Kconfig @@ -133,6 +133,28 @@ 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" + 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 ASPEED_SSIF_IPMI_BMC + depends on ARCH_ASPEED || COMPILE_TEST + depends on I2C + select SSIF_IPMI_BMC + select I2C_SLAVE + tristate "Aspeed SSIF IPMI BMC driver" + help + Provides a driver for the SSIF IPMI interface found on + Aspeed AST2500 SoC. + + The driver implements the BMC side of the SMBus system + interface (SSIF), specific for Aspeed AST2500 SoC. + config IPMB_DEVICE_INTERFACE tristate 'IPMB Interface handler' depends on I2C diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile index 0822adc2ec41..05b993f7335b 100644 --- a/drivers/char/ipmi/Makefile +++ b/drivers/char/ipmi/Makefile @@ -27,3 +27,5 @@ 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-$(CONFIG_SSIF_IPMI_BMC) += ssif_bmc.o +obj-$(CONFIG_ASPEED_SSIF_IPMI_BMC) += ssif_bmc_aspeed.o diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c new file mode 100644 index 000000000000..ae6e8750c795 --- /dev/null +++ b/drivers/char/ipmi/ssif_bmc.c @@ -0,0 +1,645 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * The driver for BMC side of SSIF interface + * + * Copyright (c) 2021, Ampere Computing LLC + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <linux/i2c.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> + +#include "ssif_bmc.h" + +/* + * Call in WRITE context + */ +static int send_ssif_bmc_response(struct ssif_bmc_ctx *ssif_bmc, bool non_blocking) +{ + unsigned long flags; + int ret; + + if (!non_blocking) { +retry: + ret = wait_event_interruptible(ssif_bmc->wait_queue, + !ssif_bmc->response_in_progress); + if (ret) + return ret; + } + + spin_lock_irqsave(&ssif_bmc->lock, flags); + if (ssif_bmc->response_in_progress) { + spin_unlock_irqrestore(&ssif_bmc->lock, flags); + if (non_blocking) + return -EAGAIN; + + goto retry; + } + + /* + * Check the response data length from userspace to determine the type + * of the response message whether it is single-part or multi-part. + */ + ssif_bmc->is_singlepart_read = + (ssif_msg_len(&ssif_bmc->response) <= (MAX_PAYLOAD_PER_TRANSACTION + 1)) ? + true : false; /* 1: byte of length */ + + ssif_bmc->response_in_progress = true; + spin_unlock_irqrestore(&ssif_bmc->lock, flags); + + return 0; +} + +/* + * Call in READ context + */ +static int receive_ssif_bmc_request(struct ssif_bmc_ctx *ssif_bmc, bool non_blocking) +{ + unsigned long flags; + int ret; + + if (!non_blocking) { +retry: + ret = wait_event_interruptible(ssif_bmc->wait_queue, + ssif_bmc->request_available); + if (ret) + return ret; + } + + spin_lock_irqsave(&ssif_bmc->lock, flags); + if (!ssif_bmc->request_available) { + spin_unlock_irqrestore(&ssif_bmc->lock, flags); + if (non_blocking) + return -EAGAIN; + goto retry; + } + spin_unlock_irqrestore(&ssif_bmc->lock, flags); + + return 0; +} + +/* 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 ssif_msg msg; + unsigned long flags; + ssize_t ret; + + mutex_lock(&ssif_bmc->file_mutex); + + ret = receive_ssif_bmc_request(ssif_bmc, file->f_flags & O_NONBLOCK); + if (ret < 0) + goto out; + + spin_lock_irqsave(&ssif_bmc->lock, flags); + count = min_t(ssize_t, count, ssif_msg_len(&ssif_bmc->request)); + 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); +out: + mutex_unlock(&ssif_bmc->file_mutex); + + 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 ssif_msg msg; + unsigned long flags; + ssize_t ret; + + if (count > sizeof(struct ssif_msg)) + return -EINVAL; + + mutex_lock(&ssif_bmc->file_mutex); + + ret = copy_from_user(&msg, buf, count); + if (ret) + goto out; + + spin_lock_irqsave(&ssif_bmc->lock, flags); + if (count >= ssif_msg_len(&ssif_bmc->response)) + memcpy(&ssif_bmc->response, &msg, count); + else + ret = -EINVAL; + spin_unlock_irqrestore(&ssif_bmc->lock, flags); + + if (ret) + goto out; + + ret = send_ssif_bmc_response(ssif_bmc, file->f_flags & O_NONBLOCK); + if (!ret && ssif_bmc->set_ssif_bmc_status) + ssif_bmc->set_ssif_bmc_status(ssif_bmc, SSIF_BMC_READY); +out: + mutex_unlock(&ssif_bmc->file_mutex); + + return (ret < 0) ? ret : count; +} + +static long ssif_bmc_ioctl(struct file *file, unsigned int cmd, unsigned long param) +{ + return 0; +} + +static unsigned int ssif_bmc_poll(struct file *file, poll_table *wait) +{ + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); + unsigned int mask = 0; + + mutex_lock(&ssif_bmc->file_mutex); + poll_wait(file, &ssif_bmc->wait_queue, wait); + + /* + * The request message is now available so userspace application can + * get the request + */ + if (ssif_bmc->request_available) + mask |= POLLIN; + + mutex_unlock(&ssif_bmc->file_mutex); + return mask; +} + +/* + * System calls to device interface for user apps + */ +static const struct file_operations ssif_bmc_fops = { + .owner = THIS_MODULE, + .read = ssif_bmc_read, + .write = ssif_bmc_write, + .poll = ssif_bmc_poll, + .unlocked_ioctl = ssif_bmc_ioctl, +}; + +/* Called with ssif_bmc->lock held. */ +static int handle_request(struct ssif_bmc_ctx *ssif_bmc) +{ + if (ssif_bmc->set_ssif_bmc_status) + ssif_bmc->set_ssif_bmc_status(ssif_bmc, SSIF_BMC_BUSY); + + /* Request message is available to process */ + ssif_bmc->request_available = true; + /* + * This is the new READ request. + * Clear the response buffer of the previous transaction + */ + memset(&ssif_bmc->response, 0, sizeof(struct ssif_msg)); + wake_up_all(&ssif_bmc->wait_queue); + return 0; +} + +/* Called with ssif_bmc->lock held. */ +static int 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; + memset(&ssif_bmc->response_buf, 0, MAX_PAYLOAD_PER_TRANSACTION); + wake_up_all(&ssif_bmc->wait_queue); + return 0; +} + +static void set_multipart_response_buffer(struct ssif_bmc_ctx *ssif_bmc, u8 *val) +{ + u8 response_len = 0; + int idx = 0; + u8 data_len; + + data_len = ssif_bmc->response.len; + switch (ssif_bmc->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. + */ + *val = MAX_PAYLOAD_PER_TRANSACTION; + ssif_bmc->remain_len = data_len - MAX_IPMI_DATA_PER_START_TRANSACTION; + ssif_bmc->block_num = 0; + + ssif_bmc->response_buf[idx++] = 0x00; /* Start Flag */ + ssif_bmc->response_buf[idx++] = 0x01; /* Start Flag */ + ssif_bmc->response_buf[idx++] = ssif_bmc->response.netfn_lun; + ssif_bmc->response_buf[idx++] = ssif_bmc->response.cmd; + ssif_bmc->response_buf[idx++] = ssif_bmc->response.payload[0]; + + response_len = MAX_PAYLOAD_PER_TRANSACTION - idx; + + memcpy(&ssif_bmc->response_buf[idx], &ssif_bmc->response.payload[1], + response_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 + * + * Return length is: remain response plus block number + */ + *val = ssif_bmc->remain_len + 1; + ssif_bmc->block_num = 0xFF; + ssif_bmc->response_buf[idx++] = ssif_bmc->block_num; + response_len = ssif_bmc->remain_len; + } 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 + */ + *val = MAX_PAYLOAD_PER_TRANSACTION; + ssif_bmc->remain_len -= MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION; + response_len = MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION; + ssif_bmc->response_buf[idx++] = ssif_bmc->block_num; + ssif_bmc->block_num++; + } + + memcpy(&ssif_bmc->response_buf[idx], + ssif_bmc->response.payload + 1 + ssif_bmc->nbytes_processed, + response_len); + break; + + default: + /* Do not expect to go to this case */ + pr_err("Error: Unexpected SMBus command received 0x%x\n", ssif_bmc->smbus_cmd); + break; + } + + ssif_bmc->nbytes_processed += response_len; +} + +static void set_singlepart_response_buffer(struct ssif_bmc_ctx *ssif_bmc, u8 *val) +{ + u8 *buf = (u8 *)&ssif_bmc->response; + + /* + * Do not expect the IPMI response has data length 0. + * With some I2C SMBus controllers (Aspeed I2C), return 0 for + * the SMBus Read Request callback might cause bad state for + * the bus. So return 1 byte length so that master will + * resend the Read Request because the length of response is + * less than a normal IPMI response. + * + * Otherwise, return the length of IPMI response + */ + *val = (buf[ssif_bmc->msg_idx]) ? buf[ssif_bmc->msg_idx] : 0x1; +} + +/* Process the IPMI response that will be read by master */ +static void handle_read_processed(struct ssif_bmc_ctx *ssif_bmc, u8 *val) +{ + u8 *buf; + u8 pec_len, addr, len; + u8 pec = 0; + + pec_len = ssif_bmc->pec_support ? 1 : 0; + /* PEC - Start Read Address */ + addr = GET_8BIT_ADDR(ssif_bmc->client->addr); + pec = i2c_smbus_pec(pec, &addr, 1); + /* PEC - SSIF Command */ + pec = i2c_smbus_pec(pec, &ssif_bmc->smbus_cmd, 1); + /* PEC - Restart Write Address */ + addr = addr | 0x01; + pec = i2c_smbus_pec(pec, &addr, 1); + + if (ssif_bmc->is_singlepart_read) { + /* Single-part Read processing */ + buf = (u8 *)&ssif_bmc->response; + + if (ssif_bmc->response.len && ssif_bmc->msg_idx < ssif_bmc->response.len) { + ssif_bmc->msg_idx++; + *val = buf[ssif_bmc->msg_idx]; + } else if (ssif_bmc->response.len && + (ssif_bmc->msg_idx == ssif_bmc->response.len)) { + ssif_bmc->msg_idx++; + *val = i2c_smbus_pec(pec, buf, ssif_msg_len(&ssif_bmc->response)); + } else { + *val = 0; + } + /* Invalidate response buffer to denote it is sent */ + if (ssif_bmc->msg_idx + 1 >= (ssif_msg_len(&ssif_bmc->response) + pec_len)) + complete_response(ssif_bmc); + } else { + /* Multi-part Read processing */ + switch (ssif_bmc->smbus_cmd) { + case SSIF_IPMI_MULTIPART_READ_START: + case SSIF_IPMI_MULTIPART_READ_MIDDLE: + buf = (u8 *)&ssif_bmc->response_buf; + *val = buf[ssif_bmc->msg_idx]; + ssif_bmc->msg_idx++; + break; + default: + /* Do not expect to go to this case */ + pr_err("Error: Unexpected SMBus command received 0x%x\n", + ssif_bmc->smbus_cmd); + break; + } + len = (ssif_bmc->block_num == 0xFF) ? + ssif_bmc->remain_len + 1 : MAX_PAYLOAD_PER_TRANSACTION; + if (ssif_bmc->msg_idx == (len + 1)) { + pec = i2c_smbus_pec(pec, &len, 1); + *val = i2c_smbus_pec(pec, ssif_bmc->response_buf, len); + } + /* Invalidate response buffer to denote last response is sent */ + if (ssif_bmc->block_num == 0xFF && + ssif_bmc->msg_idx > (ssif_bmc->remain_len + pec_len)) { + complete_response(ssif_bmc); + } + } +} + +static void handle_write_received(struct ssif_bmc_ctx *ssif_bmc, u8 *val) +{ + u8 *buf; + u8 smbus_cmd; + + buf = (u8 *)&ssif_bmc->request; + if (ssif_bmc->msg_idx >= sizeof(struct ssif_msg)) + return; + + smbus_cmd = ssif_bmc->smbus_cmd; + switch (smbus_cmd) { + case SSIF_IPMI_SINGLEPART_WRITE: + /* Single-part write */ + buf[ssif_bmc->msg_idx - 1] = *val; + ssif_bmc->msg_idx++; + + break; + case SSIF_IPMI_MULTIPART_WRITE_START: + /* Reset length to zero */ + if (ssif_bmc->msg_idx == 1) + ssif_bmc->request.len = 0; + + fallthrough; + case SSIF_IPMI_MULTIPART_WRITE_MIDDLE: + case SSIF_IPMI_MULTIPART_WRITE_END: + /* Multi-part write, 2nd byte received is length */ + if (ssif_bmc->msg_idx == 1) { + ssif_bmc->request.len += *val; + ssif_bmc->recv_len = *val; + } else { + buf[ssif_bmc->msg_idx - 1 + + ssif_bmc->request.len - ssif_bmc->recv_len] = *val; + } + + ssif_bmc->msg_idx++; + + break; + default: + /* Do not expect to go to this case */ + pr_err("Error: Unexpected SMBus command received 0x%x\n", ssif_bmc->smbus_cmd); + break; + } +} + +static bool validate_pec(struct ssif_bmc_ctx *ssif_bmc) +{ + u8 rpec = 0, cpec = 0; + bool ret = true; + u8 addr, index; + u8 *buf; + + buf = (u8 *)&ssif_bmc->request; + switch (ssif_bmc->smbus_cmd) { + case SSIF_IPMI_SINGLEPART_WRITE: + if ((ssif_bmc->msg_idx - 1) == ssif_msg_len(&ssif_bmc->request)) { + /* PEC is not included */ + ssif_bmc->pec_support = false; + return true; + } + + if ((ssif_bmc->msg_idx - 1) != (ssif_msg_len(&ssif_bmc->request) + 1)) + goto error; + + /* PEC is included */ + ssif_bmc->pec_support = true; + rpec = buf[ssif_bmc->msg_idx - 2]; + addr = GET_8BIT_ADDR(ssif_bmc->client->addr); + cpec = i2c_smbus_pec(cpec, &addr, 1); + cpec = i2c_smbus_pec(cpec, &ssif_bmc->smbus_cmd, 1); + cpec = i2c_smbus_pec(cpec, buf, ssif_msg_len(&ssif_bmc->request)); + if (rpec != cpec) { + pr_err("Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec); + ret = false; + } + + break; + case SSIF_IPMI_MULTIPART_WRITE_START: + case SSIF_IPMI_MULTIPART_WRITE_MIDDLE: + case SSIF_IPMI_MULTIPART_WRITE_END: + index = ssif_bmc->request.len - ssif_bmc->recv_len; + if ((ssif_bmc->msg_idx - 1 + index) == ssif_msg_len(&ssif_bmc->request)) { + /* PEC is not included */ + ssif_bmc->pec_support = false; + return true; + } + + if ((ssif_bmc->msg_idx - 1 + index) != (ssif_msg_len(&ssif_bmc->request) + 1)) + goto error; + + /* PEC is included */ + ssif_bmc->pec_support = true; + rpec = buf[ssif_bmc->msg_idx - 2 + index]; + addr = GET_8BIT_ADDR(ssif_bmc->client->addr); + cpec = i2c_smbus_pec(cpec, &addr, 1); + cpec = i2c_smbus_pec(cpec, &ssif_bmc->smbus_cmd, 1); + cpec = i2c_smbus_pec(cpec, &ssif_bmc->recv_len, 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-bytes 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 (ssif_bmc->recv_len != 0) + cpec = i2c_smbus_pec(cpec, buf + 1 + index, ssif_bmc->recv_len); + + if (rpec != cpec) { + pr_err("Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec); + ret = false; + } + + break; + default: + break; + } + + return ret; +error: + /* Do not expect to go to this case */ + pr_err("Error: Unexpected length received %d\n", ssif_msg_len(&ssif_bmc->request)); + + return false; +} + +static void complete_write_received(struct ssif_bmc_ctx *ssif_bmc) +{ + u8 cmd = ssif_bmc->smbus_cmd; + + /* A BMC that receives an invalid PEC shall 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 + */ + if (!validate_pec(ssif_bmc)) { + pr_err("Received invalid PEC\n"); + return; + } + + if (cmd == SSIF_IPMI_SINGLEPART_WRITE || cmd == SSIF_IPMI_MULTIPART_WRITE_END) + handle_request(ssif_bmc); +} + +/* + * Callback function to handle I2C slave events + */ +static int ssif_bmc_cb(struct i2c_client *client, enum i2c_slave_event event, u8 *val) +{ + struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client); + + spin_lock(&ssif_bmc->lock); + + /* I2C Event Handler: + * I2C_SLAVE_READ_REQUESTED 0x0 + * I2C_SLAVE_WRITE_REQUESTED 0x1 + * I2C_SLAVE_READ_PROCESSED 0x2 + * I2C_SLAVE_WRITE_RECEIVED 0x3 + * I2C_SLAVE_STOP 0x4 + */ + switch (event) { + case I2C_SLAVE_READ_REQUESTED: + ssif_bmc->msg_idx = 0; + if (ssif_bmc->is_singlepart_read) + set_singlepart_response_buffer(ssif_bmc, val); + else + set_multipart_response_buffer(ssif_bmc, val); + break; + + case I2C_SLAVE_WRITE_REQUESTED: + ssif_bmc->msg_idx = 0; + break; + + case I2C_SLAVE_READ_PROCESSED: + handle_read_processed(ssif_bmc, val); + break; + + case I2C_SLAVE_WRITE_RECEIVED: + /* + * First byte is SMBUS command, not a part of SSIF message. + * SSIF request buffer starts with msg_idx 1 for the first + * buffer byte. + */ + if (ssif_bmc->msg_idx == 0) { + /* SMBUS command can vary (single or multi-part) */ + ssif_bmc->smbus_cmd = *val; + ssif_bmc->msg_idx++; + } else { + handle_write_received(ssif_bmc, val); + } + + break; + + case I2C_SLAVE_STOP: + /* + * PEC byte is appended at the end of each transaction. + * Detect PEC is support or not after receiving write request + * completely. + */ + if (ssif_bmc->last_event == I2C_SLAVE_WRITE_RECEIVED) + complete_write_received(ssif_bmc); + /* Reset message index */ + ssif_bmc->msg_idx = 0; + break; + + default: + break; + } + ssif_bmc->last_event = event; + spin_unlock(&ssif_bmc->lock); + + return 0; +} + +struct ssif_bmc_ctx *ssif_bmc_alloc(struct i2c_client *client, int sizeof_priv) +{ + struct ssif_bmc_ctx *ssif_bmc; + int ret; + + ssif_bmc = devm_kzalloc(&client->dev, sizeof(*ssif_bmc) + sizeof_priv, GFP_KERNEL); + if (!ssif_bmc) + return ERR_PTR(-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; + + mutex_init(&ssif_bmc->file_mutex); + + /* 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) + goto out; + + 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); + goto out; + } + + return ssif_bmc; + +out: + devm_kfree(&client->dev, ssif_bmc); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(ssif_bmc_alloc); + +MODULE_AUTHOR("Chuong Tran <chuong@xxxxxxxxxxxxxxxxxxxxxx>"); +MODULE_AUTHOR("Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF interface."); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/char/ipmi/ssif_bmc.h b/drivers/char/ipmi/ssif_bmc.h new file mode 100644 index 000000000000..a2ee090572db --- /dev/null +++ b/drivers/char/ipmi/ssif_bmc.h @@ -0,0 +1,92 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * The driver for BMC side of SSIF interface + * + * Copyright (c) 2021, Ampere Computing LLC + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ +#ifndef __SSIF_BMC_H__ +#define __SSIF_BMC_H__ + +#define DEVICE_NAME "ipmi-ssif-host" + +#define GET_8BIT_ADDR(addr_7bit) (((addr_7bit) << 1) & 0xff) + +#define MSG_PAYLOAD_LEN_MAX 252 + +/* A standard SMBus Transaction is limited to 32 data bytes */ +#define MAX_PAYLOAD_PER_TRANSACTION 32 + +#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 + +struct ssif_msg { + u8 len; + u8 netfn_lun; + u8 cmd; + u8 payload[MSG_PAYLOAD_LEN_MAX]; +} __packed; + +static inline u32 ssif_msg_len(struct ssif_msg *ssif_msg) +{ + return ssif_msg->len + 1; +} + +#define SSIF_BMC_BUSY 0x01 +#define SSIF_BMC_READY 0x02 + +struct ssif_bmc_ctx { + struct i2c_client *client; + struct miscdevice miscdev; + u8 smbus_cmd; + struct ssif_msg request; + bool request_available; + struct ssif_msg response; + bool response_in_progress; + /* Response buffer for Multi-part Read Transaction */ + u8 response_buf[MAX_PAYLOAD_PER_TRANSACTION]; + /* 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; + size_t msg_idx; + enum i2c_slave_event last_event; + bool pec_support; + spinlock_t lock; + wait_queue_head_t wait_queue; + struct mutex file_mutex; + void (*set_ssif_bmc_status)(struct ssif_bmc_ctx *ssif_bmc, unsigned int flags); + void *priv; +}; + +static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file) +{ + return container_of(file->private_data, struct ssif_bmc_ctx, miscdev); +} + +struct ssif_bmc_ctx *ssif_bmc_alloc(struct i2c_client *client, int sizeof_priv); + +#endif /* __SSIF_BMC_H__ */ diff --git a/drivers/char/ipmi/ssif_bmc_aspeed.c b/drivers/char/ipmi/ssif_bmc_aspeed.c new file mode 100644 index 000000000000..02abfca90986 --- /dev/null +++ b/drivers/char/ipmi/ssif_bmc_aspeed.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * The driver for BMC side of Aspeed SSIF interface + * + * Copyright (c) 2021, Ampere Computing LLC + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <linux/i2c.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/poll.h> +#include <linux/iopoll.h> + +#include "ssif_bmc.h" + +struct aspeed_i2c_bus { + struct i2c_adapter adap; + struct device *dev; + void __iomem *base; + struct reset_control *rst; + /* Synchronizes I/O mem access to base. */ + spinlock_t lock; +}; + +#define ASPEED_I2C_INTR_CTRL_REG 0x0c +#define ASPEED_I2CD_INTR_SLAVE_MATCH BIT(7) +#define ASPEED_I2CD_INTR_RX_DONE BIT(2) +void aspeed_i2c_enable_interrupt(struct aspeed_i2c_bus *bus, unsigned long mask) +{ + unsigned long current_mask; + + current_mask = readl(bus->base + ASPEED_I2C_INTR_CTRL_REG); + writel(current_mask | mask, bus->base + ASPEED_I2C_INTR_CTRL_REG); +} + +void aspeed_i2c_disable_interrupt(struct aspeed_i2c_bus *bus, unsigned long mask) +{ + unsigned long current_mask; + + current_mask = readl(bus->base + ASPEED_I2C_INTR_CTRL_REG); + writel(current_mask & ~mask, bus->base + ASPEED_I2C_INTR_CTRL_REG); +} + +void aspeed_set_ssif_bmc_status(struct ssif_bmc_ctx *ssif_bmc, unsigned int status) +{ + struct aspeed_i2c_bus *bus; + unsigned long flags; + + bus = (struct aspeed_i2c_bus *)ssif_bmc->priv; + if (!bus) + return; + + spin_lock_irqsave(&bus->lock, flags); + + if (status & SSIF_BMC_BUSY) { + /* Ignore RX_DONE and SLAVE_MATCH when slave busy processing */ + aspeed_i2c_disable_interrupt(bus, ASPEED_I2CD_INTR_RX_DONE); + aspeed_i2c_disable_interrupt(bus, ASPEED_I2CD_INTR_SLAVE_MATCH); + } else if (status & SSIF_BMC_READY) { + /* Enable RX_DONE and SLAVE_MATCH when slave ready */ + aspeed_i2c_enable_interrupt(bus, ASPEED_I2CD_INTR_RX_DONE); + aspeed_i2c_enable_interrupt(bus, ASPEED_I2CD_INTR_SLAVE_MATCH); + } + + spin_unlock_irqrestore(&bus->lock, flags); +} + +static int ssif_bmc_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct ssif_bmc_ctx *ssif_bmc; + + ssif_bmc = ssif_bmc_alloc(client, sizeof(struct aspeed_i2c_bus)); + if (IS_ERR(ssif_bmc)) + return PTR_ERR(ssif_bmc); + + ssif_bmc->priv = i2c_get_adapdata(client->adapter); + ssif_bmc->set_ssif_bmc_status = aspeed_set_ssif_bmc_status; + + return 0; +} + +static int 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); + + return 0; +} + +static const struct of_device_id ssif_bmc_match[] = { + { .compatible = "aspeed,ast2500-ssif-bmc" }, + { }, +}; + +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("Chuong Tran <chuong@xxxxxxxxxxxxxxxxxxxxxx>"); +MODULE_AUTHOR("Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Linux device driver of Aspeed BMC IPMI SSIF interface."); +MODULE_LICENSE("GPL v2"); -- 2.28.0
