linux/drivers/misc/mei/nfc.c
Tomas Winkler 79563db9dd mei: add reference counting for me clients
To support dynamic addition and removal of
me clients we add reference counter.

Update kdoc with locking requirements.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-25 09:17:56 -08:00

595 lines
12 KiB
C

/*
*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2003-2013, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/mei_cl_bus.h>
#include "mei_dev.h"
#include "client.h"
struct mei_nfc_cmd {
u8 command;
u8 status;
u16 req_id;
u32 reserved;
u16 data_size;
u8 sub_command;
u8 data[];
} __packed;
struct mei_nfc_reply {
u8 command;
u8 status;
u16 req_id;
u32 reserved;
u16 data_size;
u8 sub_command;
u8 reply_status;
u8 data[];
} __packed;
struct mei_nfc_if_version {
u8 radio_version_sw[3];
u8 reserved[3];
u8 radio_version_hw[3];
u8 i2c_addr;
u8 fw_ivn;
u8 vendor_id;
u8 radio_type;
} __packed;
struct mei_nfc_connect {
u8 fw_ivn;
u8 vendor_id;
} __packed;
struct mei_nfc_connect_resp {
u8 fw_ivn;
u8 vendor_id;
u16 me_major;
u16 me_minor;
u16 me_hotfix;
u16 me_build;
} __packed;
struct mei_nfc_hci_hdr {
u8 cmd;
u8 status;
u16 req_id;
u32 reserved;
u16 data_size;
} __packed;
#define MEI_NFC_CMD_MAINTENANCE 0x00
#define MEI_NFC_CMD_HCI_SEND 0x01
#define MEI_NFC_CMD_HCI_RECV 0x02
#define MEI_NFC_SUBCMD_CONNECT 0x00
#define MEI_NFC_SUBCMD_IF_VERSION 0x01
#define MEI_NFC_HEADER_SIZE 10
/**
* struct mei_nfc_dev - NFC mei device
*
* @cl: NFC host client
* @cl_info: NFC info host client
* @init_work: perform connection to the info client
* @send_wq: send completion wait queue
* @fw_ivn: NFC Interface Version Number
* @vendor_id: NFC manufacturer ID
* @radio_type: NFC radio type
* @bus_name: bus name
*
* @req_id: message counter
* @recv_req_id: reception message counter
*/
struct mei_nfc_dev {
struct mei_cl *cl;
struct mei_cl *cl_info;
struct work_struct init_work;
wait_queue_head_t send_wq;
u8 fw_ivn;
u8 vendor_id;
u8 radio_type;
char *bus_name;
u16 req_id;
u16 recv_req_id;
};
/* UUIDs for NFC F/W clients */
const uuid_le mei_nfc_guid = UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50,
0x94, 0xd4, 0x50, 0x26,
0x67, 0x23, 0x77, 0x5c);
static const uuid_le mei_nfc_info_guid = UUID_LE(0xd2de1625, 0x382d, 0x417d,
0x48, 0xa4, 0xef, 0xab,
0xba, 0x8a, 0x12, 0x06);
/* Vendors */
#define MEI_NFC_VENDOR_INSIDE 0x00
#define MEI_NFC_VENDOR_NXP 0x01
/* Radio types */
#define MEI_NFC_VENDOR_INSIDE_UREAD 0x00
#define MEI_NFC_VENDOR_NXP_PN544 0x01
static void mei_nfc_free(struct mei_nfc_dev *ndev)
{
if (!ndev)
return;
if (ndev->cl) {
list_del(&ndev->cl->device_link);
mei_cl_unlink(ndev->cl);
kfree(ndev->cl);
}
if (ndev->cl_info) {
list_del(&ndev->cl_info->device_link);
mei_cl_unlink(ndev->cl_info);
kfree(ndev->cl_info);
}
kfree(ndev);
}
static int mei_nfc_build_bus_name(struct mei_nfc_dev *ndev)
{
struct mei_device *dev;
if (!ndev->cl)
return -ENODEV;
dev = ndev->cl->dev;
switch (ndev->vendor_id) {
case MEI_NFC_VENDOR_INSIDE:
switch (ndev->radio_type) {
case MEI_NFC_VENDOR_INSIDE_UREAD:
ndev->bus_name = "microread";
return 0;
default:
dev_err(dev->dev, "Unknown radio type 0x%x\n",
ndev->radio_type);
return -EINVAL;
}
case MEI_NFC_VENDOR_NXP:
switch (ndev->radio_type) {
case MEI_NFC_VENDOR_NXP_PN544:
ndev->bus_name = "pn544";
return 0;
default:
dev_err(dev->dev, "Unknown radio type 0x%x\n",
ndev->radio_type);
return -EINVAL;
}
default:
dev_err(dev->dev, "Unknown vendor ID 0x%x\n",
ndev->vendor_id);
return -EINVAL;
}
return 0;
}
static int mei_nfc_connect(struct mei_nfc_dev *ndev)
{
struct mei_device *dev;
struct mei_cl *cl;
struct mei_nfc_cmd *cmd, *reply;
struct mei_nfc_connect *connect;
struct mei_nfc_connect_resp *connect_resp;
size_t connect_length, connect_resp_length;
int bytes_recv, ret;
cl = ndev->cl;
dev = cl->dev;
connect_length = sizeof(struct mei_nfc_cmd) +
sizeof(struct mei_nfc_connect);
connect_resp_length = sizeof(struct mei_nfc_cmd) +
sizeof(struct mei_nfc_connect_resp);
cmd = kzalloc(connect_length, GFP_KERNEL);
if (!cmd)
return -ENOMEM;
connect = (struct mei_nfc_connect *)cmd->data;
reply = kzalloc(connect_resp_length, GFP_KERNEL);
if (!reply) {
kfree(cmd);
return -ENOMEM;
}
connect_resp = (struct mei_nfc_connect_resp *)reply->data;
cmd->command = MEI_NFC_CMD_MAINTENANCE;
cmd->data_size = 3;
cmd->sub_command = MEI_NFC_SUBCMD_CONNECT;
connect->fw_ivn = ndev->fw_ivn;
connect->vendor_id = ndev->vendor_id;
ret = __mei_cl_send(cl, (u8 *)cmd, connect_length);
if (ret < 0) {
dev_err(dev->dev, "Could not send connect cmd\n");
goto err;
}
bytes_recv = __mei_cl_recv(cl, (u8 *)reply, connect_resp_length);
if (bytes_recv < 0) {
dev_err(dev->dev, "Could not read connect response\n");
ret = bytes_recv;
goto err;
}
dev_info(dev->dev, "IVN 0x%x Vendor ID 0x%x\n",
connect_resp->fw_ivn, connect_resp->vendor_id);
dev_info(dev->dev, "ME FW %d.%d.%d.%d\n",
connect_resp->me_major, connect_resp->me_minor,
connect_resp->me_hotfix, connect_resp->me_build);
ret = 0;
err:
kfree(reply);
kfree(cmd);
return ret;
}
static int mei_nfc_if_version(struct mei_nfc_dev *ndev)
{
struct mei_device *dev;
struct mei_cl *cl;
struct mei_nfc_cmd cmd;
struct mei_nfc_reply *reply = NULL;
struct mei_nfc_if_version *version;
size_t if_version_length;
int bytes_recv, ret;
cl = ndev->cl_info;
dev = cl->dev;
memset(&cmd, 0, sizeof(struct mei_nfc_cmd));
cmd.command = MEI_NFC_CMD_MAINTENANCE;
cmd.data_size = 1;
cmd.sub_command = MEI_NFC_SUBCMD_IF_VERSION;
ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
if (ret < 0) {
dev_err(dev->dev, "Could not send IF version cmd\n");
return ret;
}
/* to be sure on the stack we alloc memory */
if_version_length = sizeof(struct mei_nfc_reply) +
sizeof(struct mei_nfc_if_version);
reply = kzalloc(if_version_length, GFP_KERNEL);
if (!reply)
return -ENOMEM;
bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length);
if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
dev_err(dev->dev, "Could not read IF version\n");
ret = -EIO;
goto err;
}
version = (struct mei_nfc_if_version *)reply->data;
ndev->fw_ivn = version->fw_ivn;
ndev->vendor_id = version->vendor_id;
ndev->radio_type = version->radio_type;
err:
kfree(reply);
return ret;
}
static int mei_nfc_enable(struct mei_cl_device *cldev)
{
struct mei_device *dev;
struct mei_nfc_dev *ndev;
int ret;
ndev = (struct mei_nfc_dev *)cldev->priv_data;
dev = ndev->cl->dev;
ret = mei_nfc_connect(ndev);
if (ret < 0) {
dev_err(dev->dev, "Could not connect to NFC");
return ret;
}
return 0;
}
static int mei_nfc_disable(struct mei_cl_device *cldev)
{
return 0;
}
static int mei_nfc_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_device *dev;
struct mei_nfc_dev *ndev;
struct mei_nfc_hci_hdr *hdr;
u8 *mei_buf;
int err;
ndev = (struct mei_nfc_dev *) cldev->priv_data;
dev = ndev->cl->dev;
err = -ENOMEM;
mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
if (!mei_buf)
goto out;
hdr = (struct mei_nfc_hci_hdr *) mei_buf;
hdr->cmd = MEI_NFC_CMD_HCI_SEND;
hdr->status = 0;
hdr->req_id = ndev->req_id;
hdr->reserved = 0;
hdr->data_size = length;
memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
err = __mei_cl_send(ndev->cl, mei_buf, length + MEI_NFC_HEADER_SIZE);
if (err < 0)
goto out;
if (!wait_event_interruptible_timeout(ndev->send_wq,
ndev->recv_req_id == ndev->req_id, HZ)) {
dev_err(dev->dev, "NFC MEI command timeout\n");
err = -ETIME;
} else {
ndev->req_id++;
}
out:
kfree(mei_buf);
return err;
}
static int mei_nfc_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_nfc_dev *ndev;
struct mei_nfc_hci_hdr *hci_hdr;
int received_length;
ndev = (struct mei_nfc_dev *)cldev->priv_data;
received_length = __mei_cl_recv(ndev->cl, buf, length);
if (received_length < 0)
return received_length;
hci_hdr = (struct mei_nfc_hci_hdr *) buf;
if (hci_hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
ndev->recv_req_id = hci_hdr->req_id;
wake_up(&ndev->send_wq);
return 0;
}
return received_length;
}
static struct mei_cl_ops nfc_ops = {
.enable = mei_nfc_enable,
.disable = mei_nfc_disable,
.send = mei_nfc_send,
.recv = mei_nfc_recv,
};
static void mei_nfc_init(struct work_struct *work)
{
struct mei_device *dev;
struct mei_cl_device *cldev;
struct mei_nfc_dev *ndev;
struct mei_cl *cl_info;
ndev = container_of(work, struct mei_nfc_dev, init_work);
cl_info = ndev->cl_info;
dev = cl_info->dev;
mutex_lock(&dev->device_lock);
if (mei_cl_connect(cl_info, NULL) < 0) {
mutex_unlock(&dev->device_lock);
dev_err(dev->dev, "Could not connect to the NFC INFO ME client");
goto err;
}
mutex_unlock(&dev->device_lock);
if (mei_nfc_if_version(ndev) < 0) {
dev_err(dev->dev, "Could not get the NFC interface version");
goto err;
}
dev_info(dev->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
ndev->fw_ivn, ndev->vendor_id, ndev->radio_type);
mutex_lock(&dev->device_lock);
if (mei_cl_disconnect(cl_info) < 0) {
mutex_unlock(&dev->device_lock);
dev_err(dev->dev, "Could not disconnect the NFC INFO ME client");
goto err;
}
mutex_unlock(&dev->device_lock);
if (mei_nfc_build_bus_name(ndev) < 0) {
dev_err(dev->dev, "Could not build the bus ID name\n");
return;
}
cldev = mei_cl_add_device(dev, mei_nfc_guid, ndev->bus_name, &nfc_ops);
if (!cldev) {
dev_err(dev->dev, "Could not add the NFC device to the MEI bus\n");
goto err;
}
cldev->priv_data = ndev;
return;
err:
mutex_lock(&dev->device_lock);
mei_nfc_free(ndev);
mutex_unlock(&dev->device_lock);
}
int mei_nfc_host_init(struct mei_device *dev)
{
struct mei_nfc_dev *ndev;
struct mei_cl *cl_info, *cl = NULL;
struct mei_me_client *me_cl;
int ret;
/* in case of internal reset bail out
* as the device is already setup
*/
cl = mei_cl_bus_find_cl_by_uuid(dev, mei_nfc_guid);
if (cl)
return 0;
ndev = kzalloc(sizeof(struct mei_nfc_dev), GFP_KERNEL);
if (!ndev) {
ret = -ENOMEM;
goto err;
}
ndev->cl_info = mei_cl_allocate(dev);
ndev->cl = mei_cl_allocate(dev);
cl = ndev->cl;
cl_info = ndev->cl_info;
if (!cl || !cl_info) {
ret = -ENOMEM;
goto err;
}
/* check for valid client id */
me_cl = mei_me_cl_by_uuid(dev, &mei_nfc_info_guid);
if (!me_cl) {
dev_info(dev->dev, "nfc: failed to find the client\n");
ret = -ENOTTY;
goto err;
}
cl_info->me_client_id = me_cl->client_id;
cl_info->cl_uuid = me_cl->props.protocol_name;
mei_me_cl_put(me_cl);
ret = mei_cl_link(cl_info, MEI_HOST_CLIENT_ID_ANY);
if (ret)
goto err;
list_add_tail(&cl_info->device_link, &dev->device_list);
/* check for valid client id */
me_cl = mei_me_cl_by_uuid(dev, &mei_nfc_guid);
if (!me_cl) {
dev_info(dev->dev, "nfc: failed to find the client\n");
ret = -ENOTTY;
goto err;
}
cl->me_client_id = me_cl->client_id;
cl->cl_uuid = me_cl->props.protocol_name;
mei_me_cl_put(me_cl);
ret = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
if (ret)
goto err;
list_add_tail(&cl->device_link, &dev->device_list);
ndev->req_id = 1;
INIT_WORK(&ndev->init_work, mei_nfc_init);
init_waitqueue_head(&ndev->send_wq);
schedule_work(&ndev->init_work);
return 0;
err:
mei_nfc_free(ndev);
return ret;
}
void mei_nfc_host_exit(struct mei_device *dev)
{
struct mei_nfc_dev *ndev;
struct mei_cl *cl;
struct mei_cl_device *cldev;
cl = mei_cl_bus_find_cl_by_uuid(dev, mei_nfc_guid);
if (!cl)
return;
cldev = cl->device;
if (!cldev)
return;
ndev = (struct mei_nfc_dev *)cldev->priv_data;
if (ndev)
cancel_work_sync(&ndev->init_work);
cldev->priv_data = NULL;
mutex_lock(&dev->device_lock);
/* Need to remove the device here
* since mei_nfc_free will unlink the clients
*/
mei_cl_remove_device(cldev);
mei_nfc_free(ndev);
mutex_unlock(&dev->device_lock);
}