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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2022 Intel Corporation.*/
#include <linux/err.h>
#include <linux/peci.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/i3c/device.h>
#include <linux/i3c/mctp/i3c-mctp.h>
#define MSG_TAG_MASK GENMASK(2, 0)
#define MCTP_SET_MSG_TAG(x, val) ((x)->flags_seq_tag |= ((val) & MSG_TAG_MASK))
#define MCTP_GET_MSG_TAG(x) ((x)->flags_seq_tag & MSG_TAG_MASK)
#define MCTP_HDR_VERSION 1
#define REQUEST_FLAGS 0xc8
#define RESPONSE_FLAGS 0xc0
#define PECI_REQUEST 0x80
#define PECI_RESPONSE 0
#define PECI_PAYLOAD_SIZE 59
#define I3C_PECI_MCTP_TIMEOUT_VALUE_MS 800
struct mctp_peci_vdm_hdr {
u8 type;
__be16 vendor_id;
u8 instance_req_d;
u8 vendor_code;
} __packed;
static const struct mctp_protocol_hdr mctp_protocol_hdr_template = {
.ver = MCTP_HDR_VERSION,
.flags_seq_tag = REQUEST_FLAGS
};
static const struct mctp_peci_vdm_hdr mctp_peci_vdm_hdr_template = {
.type = MCTP_MSG_TYPE_VDM_PCI,
.instance_req_d = PECI_REQUEST,
.vendor_code = MCTP_VDM_PCI_INTEL_PECI
};
struct i3c_peci {
struct peci_adapter *adapter;
struct device *dev;
struct i3c_device *i3cdev;
struct i3c_mctp_client *client;
u8 tag;
};
static void
prepare_tx_packet(struct i3c_mctp_packet *tx_packet,
u8 tx_len, u8 rx_len, u8 *tx_buf, u8 dest, u8 tag)
{
struct mctp_protocol_hdr *mctp_protocol_hdr;
struct mctp_peci_vdm_hdr *mctp_peci_vdm_hdr;
u8 *peci_payload;
mctp_protocol_hdr = (struct mctp_protocol_hdr *)&tx_packet->data.protocol_hdr;
*mctp_protocol_hdr = mctp_protocol_hdr_template;
mctp_protocol_hdr->dest = dest;
MCTP_SET_MSG_TAG(mctp_protocol_hdr, tag);
mctp_peci_vdm_hdr = (struct mctp_peci_vdm_hdr *)&tx_packet->data.payload;
*mctp_peci_vdm_hdr = mctp_peci_vdm_hdr_template;
mctp_peci_vdm_hdr->vendor_id = cpu_to_be16(MCTP_VDM_PCI_INTEL_VENDOR_ID);
peci_payload = (u8 *)(tx_packet->data.payload) + sizeof(struct mctp_peci_vdm_hdr);
peci_payload[0] = tx_len;
peci_payload[1] = rx_len;
memcpy(&peci_payload[2], tx_buf, tx_len);
tx_packet->size = I3C_MCTP_PACKET_SIZE;
}
static int
verify_rx_packet(struct peci_adapter *adapter, struct i3c_mctp_packet *rx_packet, u8 tag)
{
struct i3c_peci *priv = peci_get_adapdata(adapter);
bool invalid_packet = false;
struct mctp_protocol_hdr *mctp_protocol_hdr;
struct mctp_peci_vdm_hdr *mctp_message_hdr;
u8 expected_flags;
expected_flags = (RESPONSE_FLAGS | (tag & MSG_TAG_MASK));
mctp_protocol_hdr = (struct mctp_protocol_hdr *)&rx_packet->data.protocol_hdr;
mctp_message_hdr = (struct mctp_peci_vdm_hdr *)&rx_packet->data.payload;
if (mctp_protocol_hdr->flags_seq_tag != expected_flags) {
dev_dbg(priv->dev,
"mismatch in mctp flags: expected: 0x%.2x, got: 0x%.2x",
expected_flags, mctp_protocol_hdr->flags_seq_tag);
invalid_packet = true;
}
if (mctp_message_hdr->instance_req_d != PECI_RESPONSE) {
dev_dbg(priv->dev,
"mismatch in PECI response code: expected: 0x%.2x, got: 0x%.2x",
PECI_RESPONSE, mctp_message_hdr->instance_req_d);
invalid_packet = true;
}
if (invalid_packet) {
dev_warn_ratelimited(priv->dev, "unexpected peci response found\n");
return -EIO;
}
return 0;
}
static struct i3c_mctp_packet *i3c_peci_send_receive(struct peci_adapter *adapter,
struct i3c_device *i3cdev,
u8 tx_len, u8 rx_len, u8 *tx_buf, u8 dest_eid)
{
unsigned long timeout = msecs_to_jiffies(I3C_PECI_MCTP_TIMEOUT_VALUE_MS);
struct i3c_peci *priv = peci_get_adapdata(adapter);
struct i3c_mctp_packet *tx_packet;
struct i3c_mctp_packet *rx_packet;
u8 tag = priv->tag;
int ret;
tx_packet = i3c_mctp_packet_alloc(GFP_KERNEL);
if (!tx_packet)
return ERR_PTR(-ENOMEM);
prepare_tx_packet(tx_packet, tx_len, rx_len, tx_buf, dest_eid, tag);
print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, &tx_packet->data, tx_packet->size);
ret = i3c_mctp_send_packet(i3cdev, tx_packet);
if (ret) {
i3c_mctp_packet_free(tx_packet);
return ERR_PTR(ret);
}
i3c_mctp_packet_free(tx_packet);
priv->tag++;
rx_packet = i3c_mctp_receive_packet(priv->client, timeout);
if (IS_ERR(rx_packet))
return rx_packet;
ret = verify_rx_packet(adapter, rx_packet, tag);
if (ret) {
i3c_mctp_packet_free(rx_packet);
return ERR_PTR(ret);
}
print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, &rx_packet->data, rx_packet->size);
return rx_packet;
}
static int
i3c_peci_xfer(struct peci_adapter *adapter, struct peci_xfer_msg *msg)
{
struct i3c_peci *priv = peci_get_adapdata(adapter);
struct i3c_mctp_packet *rx_packet;
u8 domain_id = 0;
u8 dest_eid;
int ret;
if (msg->tx_len > PECI_PAYLOAD_SIZE || msg->rx_len > PECI_PAYLOAD_SIZE)
return -EINVAL;
if (msg->tx_len > 2)
domain_id = msg->tx_buf[1] >> 1;
ret = i3c_mctp_get_eid(priv->client, domain_id, &dest_eid);
if (ret)
return -ENODEV;
rx_packet = i3c_peci_send_receive(adapter, priv->i3cdev,
msg->tx_len, msg->rx_len, msg->tx_buf, dest_eid);
if (IS_ERR(rx_packet))
return PTR_ERR(rx_packet);
memcpy(msg->rx_buf, (u8 *)(rx_packet->data.payload) + sizeof(struct mctp_peci_vdm_hdr),
msg->rx_len);
i3c_mctp_packet_free(rx_packet);
return 0;
}
static int i3c_peci_probe(struct platform_device *pdev)
{
struct peci_adapter *adapter;
struct i3c_peci *priv;
int ret;
adapter = peci_alloc_adapter(&pdev->dev, sizeof(*priv));
if (!adapter)
return -ENOMEM;
priv = peci_get_adapdata(adapter);
platform_set_drvdata(pdev, priv);
priv->i3cdev = dev_to_i3cdev(pdev->dev.parent);
priv->dev = &pdev->dev;
adapter->owner = THIS_MODULE;
strscpy(adapter->name, pdev->name, sizeof(adapter->name));
adapter->xfer = i3c_peci_xfer;
adapter->peci_revision = 0x41;
priv->adapter = adapter;
priv->client = i3c_mctp_add_peci_client(priv->i3cdev);
if (IS_ERR(priv->client)) {
ret = -ENOMEM;
goto out_put_device;
}
ret = peci_add_adapter(adapter);
if (ret)
goto out_del_client;
return 0;
out_del_client:
i3c_mctp_remove_peci_client(priv->client);
out_put_device:
put_device(&adapter->dev);
return ret;
}
static int i3c_peci_remove(struct platform_device *pdev)
{
struct i3c_peci *priv = platform_get_drvdata(pdev);
peci_del_adapter(priv->adapter);
i3c_mctp_remove_peci_client(priv->client);
return 0;
}
static struct platform_driver i3c_peci_driver = {
.probe = i3c_peci_probe,
.remove = i3c_peci_remove,
.driver = {
.name = "peci-i3c",
},
};
module_platform_driver(i3c_peci_driver);
MODULE_AUTHOR("Oleksandr Shulzhenko <oleksandr.shulzhenko.viktorovych@intel.com>");
MODULE_DESCRIPTION("I3C PECI driver");
MODULE_LICENSE("GPL");
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