drivers/misc/mei/bus-fixup.c - kernel/bruno - Git at Google

 /*
  *
  * 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)

 static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;

 #define MEI_UUID_NFC_HCI UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50, \
 			0x94, 0xd4, 0x50, 0x26, 0x67, 0x23, 0x77, 0x5c)

 #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;


 #define MEI_NFC_CMD_MAINTENANCE 0x00
 #define MEI_NFC_SUBCMD_IF_VERSION 0x01

 /* 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

 /**
  * 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 < if_version_length) {
 		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;
 }

 /**
  * mei_nfc - The nfc fixup function. The function retrieves nfc radio
  *    name and set is as device attribute so we can load
  *    the proper device driver for it
  *
  * @cldev: me client device (nfc)
  */
 static void mei_nfc(struct mei_cl_device *cldev)
 {
 	struct mei_device *bus;
 	struct mei_cl *cl;
 	struct mei_me_client *me_cl = NULL;
 	struct mei_nfc_if_version ver;
 	const char *radio_name = NULL;
 	int ret;

 	bus = cldev->bus;

 	dev_dbg(bus->dev, "running hook %s: %pUl match=%d\n",
 		__func__, mei_me_cl_uuid(cldev->me_cl), cldev->do_match);

 	mutex_lock(&bus->device_lock);
 	/* we need to connect to INFO GUID */
 	cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
 	if (IS_ERR(cl)) {
 		ret = PTR_ERR(cl);
 		cl = NULL;
 		dev_err(bus->dev, "nfc hook alloc failed %d\n", ret);
 		goto out;
 	}

 	me_cl = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
 	if (!me_cl) {
 		ret = -ENOTTY;
 		dev_err(bus->dev, "Cannot find nfc info %d\n", ret);
 		goto out;
 	}

 	ret = mei_cl_connect(cl, me_cl, NULL);
 	if (ret < 0) {
 		dev_err(&cldev->dev, "Can't connect to the NFC INFO ME ret = %d\n",
 			ret);
 		goto out;
 	}

 	mutex_unlock(&bus->device_lock);

 	ret = mei_nfc_if_version(cl, &ver);
 	if (ret)
 		goto disconnect;

 	radio_name = mei_nfc_radio_name(&ver);

 	if (!radio_name) {
 		ret = -ENOENT;
 		dev_err(&cldev->dev, "Can't get the NFC interface version ret = %d\n",
 			ret);
 		goto disconnect;
 	}

 	dev_dbg(bus->dev, "nfc radio %s\n", radio_name);
 	strlcpy(cldev->name, radio_name, sizeof(cldev->name));

 disconnect:
 	mutex_lock(&bus->device_lock);
 	if (mei_cl_disconnect(cl) < 0)
 		dev_err(bus->dev, "Can't disconnect the NFC INFO ME\n");

 	mei_cl_flush_queues(cl, NULL);

 out:
 	mei_cl_unlink(cl);
 	mutex_unlock(&bus->device_lock);
 	mei_me_cl_put(me_cl);
 	kfree(cl);

 	if (ret)
 		cldev->do_match = 0;

 	dev_dbg(bus->dev, "end of fixup match = %d\n", cldev->do_match);
 }

 #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_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
 };

 /**
  * mei_cldev_fixup - run fixup handlers
  *
  * @cldev: me client device
  */
 void mei_cl_bus_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);
 	}
 }
	/*
	*
	* 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)

	static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;

	#define MEI_UUID_NFC_HCI UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50, \
	0x94, 0xd4, 0x50, 0x26, 0x67, 0x23, 0x77, 0x5c)

	#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;


	#define MEI_NFC_CMD_MAINTENANCE 0x00
	#define MEI_NFC_SUBCMD_IF_VERSION 0x01

	/* 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

	/**
	* 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 < if_version_length) {
	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;
	}

	/**
	* mei_nfc - The nfc fixup function. The function retrieves nfc radio
	* name and set is as device attribute so we can load
	* the proper device driver for it
	*
	* @cldev: me client device (nfc)
	*/
	static void mei_nfc(struct mei_cl_device *cldev)
	{
	struct mei_device *bus;
	struct mei_cl *cl;
	struct mei_me_client *me_cl = NULL;
	struct mei_nfc_if_version ver;
	const char *radio_name = NULL;
	int ret;

	bus = cldev->bus;

	dev_dbg(bus->dev, "running hook %s: %pUl match=%d\n",
	__func__, mei_me_cl_uuid(cldev->me_cl), cldev->do_match);

	mutex_lock(&bus->device_lock);
	/* we need to connect to INFO GUID */
	cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
	if (IS_ERR(cl)) {
	ret = PTR_ERR(cl);
	cl = NULL;
	dev_err(bus->dev, "nfc hook alloc failed %d\n", ret);
	goto out;
	}

	me_cl = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
	if (!me_cl) {
	ret = -ENOTTY;
	dev_err(bus->dev, "Cannot find nfc info %d\n", ret);
	goto out;
	}

	ret = mei_cl_connect(cl, me_cl, NULL);
	if (ret < 0) {
	dev_err(&cldev->dev, "Can't connect to the NFC INFO ME ret = %d\n",
	ret);
	goto out;
	}

	mutex_unlock(&bus->device_lock);

	ret = mei_nfc_if_version(cl, &ver);
	if (ret)
	goto disconnect;

	radio_name = mei_nfc_radio_name(&ver);

	if (!radio_name) {
	ret = -ENOENT;
	dev_err(&cldev->dev, "Can't get the NFC interface version ret = %d\n",
	ret);
	goto disconnect;
	}

	dev_dbg(bus->dev, "nfc radio %s\n", radio_name);
	strlcpy(cldev->name, radio_name, sizeof(cldev->name));

	disconnect:
	mutex_lock(&bus->device_lock);
	if (mei_cl_disconnect(cl) < 0)
	dev_err(bus->dev, "Can't disconnect the NFC INFO ME\n");

	mei_cl_flush_queues(cl, NULL);

	out:
	mei_cl_unlink(cl);
	mutex_unlock(&bus->device_lock);
	mei_me_cl_put(me_cl);
	kfree(cl);

	if (ret)
	cldev->do_match = 0;

	dev_dbg(bus->dev, "end of fixup match = %d\n", cldev->do_match);
	}

	#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_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
	};

	/**
	* mei_cldev_fixup - run fixup handlers
	*
	* @cldev: me client device
	*/
	void mei_cl_bus_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);
	}
	}