linux/drivers/misc/mei/bus-fixup.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/uuid.h>

#include <linux/mei_cl_bus.h>

#include "mei_dev.h"
#include "client.h"

#define MEI_UUID_NFC_INFO UUID_LE(0xd2de1625, 0x382d, 0x417d, \
			0x48, 0xa4, 0xef, 0xab, 0xba, 0x8a, 0x12, 0x06)

#define MEI_UUID_ANY NULL_UUID_LE

/**
 * number_of_connections - determine whether an client be on the bus
 *    according number of connections
 *    We support only clients:
 *       1. with single connection
 *       2. and fixed clients (max_number_of_connections == 0)
 *
 * @cldev: me clients device
 */
static void number_of_connections(struct mei_cl_device *cldev)
{
	dev_dbg(&cldev->dev, "running hook %s on %pUl\n",
			__func__, mei_me_cl_uuid(cldev->me_cl));

	if (cldev->me_cl->props.max_number_of_connections > 1)
		cldev->do_match = 0;
}

/**
 * blacklist - blacklist a client from the bus
 *
 * @cldev: me clients device
 */
static void blacklist(struct mei_cl_device *cldev)
{
	dev_dbg(&cldev->dev, "running hook %s on %pUl\n",
			__func__, mei_me_cl_uuid(cldev->me_cl));
	cldev->do_match = 0;
}

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
 *
 * @me_cl: NFC me client
 * @cl: NFC host client
 * @cl_info: NFC info host client
 * @init_work: perform connection to the info client
 * @fw_ivn: NFC Interface Version Number
 * @vendor_id: NFC manufacturer ID
 * @radio_type: NFC radio type
 * @bus_name: bus name
 *
 */
struct mei_nfc_dev {
	struct mei_me_client *me_cl;
	struct mei_cl *cl;
	struct mei_cl *cl_info;
	struct work_struct init_work;
	u8 fw_ivn;
	u8 vendor_id;
	u8 radio_type;
	const char *bus_name;
};

/* 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 = MEI_UUID_NFC_INFO;

/* 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);
	}

	mei_me_cl_put(ndev->me_cl);
	kfree(ndev);
}

/**
 * mei_nfc_if_version - get NFC interface version
 *
 * @cl: host client (nfc info)
 * @ver: NFC interface version to be filled in
 *
 * Return: 0 on success; < 0 otherwise
 */
static int mei_nfc_if_version(struct mei_cl *cl,
			      struct mei_nfc_if_version *ver)
{
	struct mei_device *bus;
	struct mei_nfc_cmd cmd = {
		.command = MEI_NFC_CMD_MAINTENANCE,
		.data_size = 1,
		.sub_command = MEI_NFC_SUBCMD_IF_VERSION,
	};
	struct mei_nfc_reply *reply = NULL;
	size_t if_version_length;
	int bytes_recv, ret;

	bus = cl->dev;

	WARN_ON(mutex_is_locked(&bus->device_lock));

	ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(struct mei_nfc_cmd), 1);
	if (ret < 0) {
		dev_err(bus->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;

	ret = 0;
	bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length);
	if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
		dev_err(bus->dev, "Could not read IF version\n");
		ret = -EIO;
		goto err;
	}

	memcpy(ver, reply->data, sizeof(struct mei_nfc_if_version));

	dev_info(bus->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
		ver->fw_ivn, ver->vendor_id, ver->radio_type);

err:
	kfree(reply);
	return ret;
}

/**
 * mei_nfc_radio_name - derive nfc radio name from the interface version
 *
 * @ver: NFC radio version
 *
 * Return: radio name string
 */
static const char *mei_nfc_radio_name(struct mei_nfc_if_version *ver)
{

	if (ver->vendor_id == MEI_NFC_VENDOR_INSIDE) {
		if (ver->radio_type == MEI_NFC_VENDOR_INSIDE_UREAD)
			return "microread";
	}

	if (ver->vendor_id == MEI_NFC_VENDOR_NXP) {
		if (ver->radio_type == MEI_NFC_VENDOR_NXP_PN544)
			return "pn544";
	}

	return NULL;
}

static void mei_nfc_init(struct work_struct *work)
{
	struct mei_device *bus;
	struct mei_cl_device *cldev;
	struct mei_nfc_dev *ndev;
	struct mei_cl *cl_info;
	struct mei_me_client *me_cl_info;
	struct mei_nfc_if_version version;

	ndev = container_of(work, struct mei_nfc_dev, init_work);

	cl_info = ndev->cl_info;
	bus = cl_info->dev;

	mutex_lock(&bus->device_lock);

	/* check for valid client id */
	me_cl_info = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
	if (!me_cl_info) {
		mutex_unlock(&bus->device_lock);
		dev_info(bus->dev, "nfc: failed to find the info client\n");
		goto err;
	}

	if (mei_cl_connect(cl_info, me_cl_info, NULL) < 0) {
		mei_me_cl_put(me_cl_info);
		mutex_unlock(&bus->device_lock);
		dev_err(bus->dev, "Could not connect to the NFC INFO ME client");

		goto err;
	}
	mei_me_cl_put(me_cl_info);
	mutex_unlock(&bus->device_lock);

	if (mei_nfc_if_version(cl_info, &version) < 0) {
		dev_err(bus->dev, "Could not get the NFC interface version");

		goto err;
	}

	ndev->fw_ivn = version.fw_ivn;
	ndev->vendor_id = version.vendor_id;
	ndev->radio_type = version.radio_type;

	dev_info(bus->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(&bus->device_lock);

	if (mei_cl_disconnect(cl_info) < 0) {
		mutex_unlock(&bus->device_lock);
		dev_err(bus->dev, "Could not disconnect the NFC INFO ME client");

		goto err;
	}

	mutex_unlock(&bus->device_lock);

	ndev->bus_name = mei_nfc_radio_name(&version);

	if (!ndev->bus_name) {
		dev_err(bus->dev, "Could not build the bus ID name\n");
		return;
	}

	cldev = mei_cl_add_device(bus, ndev->me_cl, ndev->cl,
				  ndev->bus_name);
	if (!cldev) {
		dev_err(bus->dev, "Could not add the NFC device to the MEI bus\n");

		goto err;
	}

	cldev->priv_data = ndev;


	return;

err:
	mutex_lock(&bus->device_lock);
	mei_nfc_free(ndev);
	mutex_unlock(&bus->device_lock);

}


int mei_nfc_host_init(struct mei_device *bus, struct mei_me_client *me_cl)
{
	struct mei_nfc_dev *ndev;
	struct mei_cl *cl_info, *cl;
	int ret;


	/* in case of internal reset bail out
	 * as the device is already setup
	 */
	cl = mei_cl_bus_find_cl_by_uuid(bus, mei_nfc_guid);
	if (cl)
		return 0;

	ndev = kzalloc(sizeof(struct mei_nfc_dev), GFP_KERNEL);
	if (!ndev) {
		ret = -ENOMEM;
		goto err;
	}

	ndev->me_cl = mei_me_cl_get(me_cl);
	if (!ndev->me_cl) {
		ret = -ENODEV;
		goto err;
	}

	cl_info = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
	if (IS_ERR(cl_info)) {
		ret = PTR_ERR(cl_info);
		goto err;
	}

	list_add_tail(&cl_info->device_link, &bus->device_list);

	ndev->cl_info = cl_info;

	cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
	if (IS_ERR(cl)) {
		ret = PTR_ERR(cl);
		goto err;
	}

	list_add_tail(&cl->device_link, &bus->device_list);

	ndev->cl = cl;

	INIT_WORK(&ndev->init_work, mei_nfc_init);
	schedule_work(&ndev->init_work);

	return 0;

err:
	mei_nfc_free(ndev);

	return ret;
}

void mei_nfc_host_exit(struct mei_device *bus)
{
	struct mei_nfc_dev *ndev;
	struct mei_cl *cl;
	struct mei_cl_device *cldev;

	cl = mei_cl_bus_find_cl_by_uuid(bus, mei_nfc_guid);
	if (!cl)
		return;

	cldev = cl->cldev;
	if (!cldev)
		return;

	ndev = (struct mei_nfc_dev *)cldev->priv_data;
	if (ndev)
		cancel_work_sync(&ndev->init_work);

	cldev->priv_data = NULL;

	/* Need to remove the device here
	 * since mei_nfc_free will unlink the clients
	 */
	mei_cl_remove_device(cldev);

	mutex_lock(&bus->device_lock);
	mei_nfc_free(ndev);
	mutex_unlock(&bus->device_lock);
}

#define MEI_FIXUP(_uuid, _hook) { _uuid, _hook }

static struct mei_fixup {

	const uuid_le uuid;
	void (*hook)(struct mei_cl_device *cldev);
} mei_fixups[] = {
	MEI_FIXUP(MEI_UUID_ANY, number_of_connections),
	MEI_FIXUP(MEI_UUID_NFC_INFO, blacklist),
};

/**
 * mei_cl_dev_fixup - run fixup handlers
 *
 * @cldev: me client device
 */
void mei_cl_dev_fixup(struct mei_cl_device *cldev)
{
	struct mei_fixup *f;
	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
	int i;

	for (i = 0; i < ARRAY_SIZE(mei_fixups); i++) {

		f = &mei_fixups[i];
		if (uuid_le_cmp(f->uuid, MEI_UUID_ANY) == 0 ||
		    uuid_le_cmp(f->uuid, *uuid) == 0)
			f->hook(cldev);
	}
}