[deliverable/linux.git] / drivers / nfc / mei_phy.c

/*
 * MEI Library for mei bus nfc device access
 *
 * Copyright (C) 2013  Intel Corporation. All rights reserved.
 *
 * 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 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 <http://www.gnu.org/licenses/>.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/nfc.h>

#include "mei_phy.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


#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)

#define MEI_DUMP_SKB_IN(info, skb)				\
do {								\
	pr_debug("%s:\n", info);				\
	print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET,	\
			16, 1, (skb)->data, (skb)->len, false);	\
} while (0)

#define MEI_DUMP_SKB_OUT(info, skb)				\
do {								\
	pr_debug("%s:\n", info);				\
	print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET,	\
			16, 1, (skb)->data, (skb)->len, false);	\
} while (0)


static int mei_nfc_if_version(struct nfc_mei_phy *phy)
{

	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, r;

	pr_info("%s\n", __func__);

	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;

	r = mei_cl_send(phy->device, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
	if (r < 0) {
		pr_err("Could not send IF version cmd\n");
		return r;
	}

	/* 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(phy->device, (u8 *)reply, if_version_length);
	if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
		pr_err("Could not read IF version\n");
		r = -EIO;
		goto err;
	}

	version = (struct mei_nfc_if_version *)reply->data;

	phy->fw_ivn = version->fw_ivn;
	phy->vendor_id = version->vendor_id;
	phy->radio_type = version->radio_type;

err:
	kfree(reply);
	return r;
}

static int mei_nfc_connect(struct nfc_mei_phy *phy)
{
	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, r;

	pr_info("%s\n", __func__);

	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 = phy->fw_ivn;
	connect->vendor_id = phy->vendor_id;

	r = mei_cl_send(phy->device, (u8 *)cmd, connect_length);
	if (r < 0) {
		pr_err("Could not send connect cmd %d\n", r);
		goto err;
	}

	bytes_recv = mei_cl_recv(phy->device, (u8 *)reply, connect_resp_length);
	if (bytes_recv < 0) {
		r = bytes_recv;
		pr_err("Could not read connect response %d\n", r);
		goto err;
	}

	pr_info("IVN 0x%x Vendor ID 0x%x\n",
		 connect_resp->fw_ivn, connect_resp->vendor_id);

	pr_info("ME FW %d.%d.%d.%d\n",
		connect_resp->me_major, connect_resp->me_minor,
		connect_resp->me_hotfix, connect_resp->me_build);

	r = 0;

err:
	kfree(reply);
	kfree(cmd);

	return r;
}

static int mei_nfc_send(struct nfc_mei_phy *phy, u8 *buf, size_t length)
{
	struct mei_nfc_hci_hdr *hdr;
	u8 *mei_buf;
	int err;

	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 = phy->req_id;
	hdr->reserved = 0;
	hdr->data_size = length;

	memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
	err = mei_cl_send(phy->device, mei_buf, length + MEI_NFC_HEADER_SIZE);
	if (err < 0)
		goto out;

	if (!wait_event_interruptible_timeout(phy->send_wq,
				phy->recv_req_id == phy->req_id, HZ)) {
		pr_err("NFC MEI command timeout\n");
		err = -ETIME;
	} else {
		phy->req_id++;
	}
out:
	kfree(mei_buf);
	return err;
}

/*
 * Writing a frame must not return the number of written bytes.
 * It must return either zero for success, or <0 for error.
 * In addition, it must not alter the skb
 */
static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
{
	struct nfc_mei_phy *phy = phy_id;
	int r;

	MEI_DUMP_SKB_OUT("mei frame sent", skb);

	r = mei_nfc_send(phy, skb->data, skb->len);
	if (r > 0)
		r = 0;

	return r;
}

static int mei_nfc_recv(struct nfc_mei_phy *phy, u8 *buf, size_t length)
{
	struct mei_nfc_hci_hdr *hci_hdr;
	int received_length;

	received_length = mei_cl_recv(phy->device, 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) {
		phy->recv_req_id = hci_hdr->req_id;
		wake_up(&phy->send_wq);

		return 0;
	}

	return received_length;
}


static void nfc_mei_event_cb(struct mei_cl_device *device, u32 events,
			     void *context)
{
	struct nfc_mei_phy *phy = context;

	if (phy->hard_fault != 0)
		return;

	if (events & BIT(MEI_CL_EVENT_RX)) {
		struct sk_buff *skb;
		int reply_size;

		skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
		if (!skb)
			return;

		reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
		if (reply_size < MEI_NFC_HEADER_SIZE) {
			kfree_skb(skb);
			return;
		}

		skb_put(skb, reply_size);
		skb_pull(skb, MEI_NFC_HEADER_SIZE);

		MEI_DUMP_SKB_IN("mei frame read", skb);

		nfc_hci_recv_frame(phy->hdev, skb);
	}
}

static int nfc_mei_phy_enable(void *phy_id)
{
	int r;
	struct nfc_mei_phy *phy = phy_id;

	pr_info("%s\n", __func__);

	if (phy->powered == 1)
		return 0;

	r = mei_cl_enable_device(phy->device);
	if (r < 0) {
		pr_err("Could not enable device %d\n", r);
		return r;
	}

	r = mei_nfc_if_version(phy);
	if (r < 0) {
		pr_err("Could not enable device %d\n", r);
		goto err;
	}

	r = mei_nfc_connect(phy);
	if (r < 0) {
		pr_err("Could not connect to device %d\n", r);
		goto err;
	}

	r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy);
	if (r) {
		pr_err("Event cb registration failed %d\n", r);
		goto err;
	}

	phy->powered = 1;

	return 0;

err:
	phy->powered = 0;
	mei_cl_disable_device(phy->device);
	return r;
}

static void nfc_mei_phy_disable(void *phy_id)
{
	struct nfc_mei_phy *phy = phy_id;

	pr_info("%s\n", __func__);

	mei_cl_disable_device(phy->device);

	phy->powered = 0;
}

struct nfc_phy_ops mei_phy_ops = {
	.write = nfc_mei_phy_write,
	.enable = nfc_mei_phy_enable,
	.disable = nfc_mei_phy_disable,
};
EXPORT_SYMBOL_GPL(mei_phy_ops);

struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device)
{
	struct nfc_mei_phy *phy;

	phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
	if (!phy)
		return NULL;

	phy->device = device;
	init_waitqueue_head(&phy->send_wq);
	mei_cl_set_drvdata(device, phy);

	return phy;
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);

void nfc_mei_phy_free(struct nfc_mei_phy *phy)
{
	mei_cl_disable_device(phy->device);
	kfree(phy);
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_free);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("mei bus NFC device interface");
Commit	Line	Data
4912e2fe EL	1	/*
	2	* MEI Library for mei bus nfc device access
	3	*
	4	* Copyright (C) 2013 Intel Corporation. All rights reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
98b32dec	16	* along with this program; if not, see <http://www.gnu.org/licenses/>.
4912e2fe EL	17	*/
4912e2fe EL	18
17936b43 JP	19	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17936b43 JP	20
4912e2fe EL	21	#include <linux/module.h>
	22	#include <linux/slab.h>
	23	#include <linux/nfc.h>
	24
	25	#include "mei_phy.h"
	26
be9b720a TW	27	struct mei_nfc_cmd {
	28	u8 command;
	29	u8 status;
	30	u16 req_id;
	31	u32 reserved;
	32	u16 data_size;
	33	u8 sub_command;
	34	u8 data[];
	35	} __packed;
	36
	37	struct mei_nfc_reply {
	38	u8 command;
	39	u8 status;
	40	u16 req_id;
	41	u32 reserved;
	42	u16 data_size;
	43	u8 sub_command;
	44	u8 reply_status;
	45	u8 data[];
	46	} __packed;
	47
	48	struct mei_nfc_if_version {
	49	u8 radio_version_sw[3];
	50	u8 reserved[3];
	51	u8 radio_version_hw[3];
	52	u8 i2c_addr;
	53	u8 fw_ivn;
	54	u8 vendor_id;
	55	u8 radio_type;
	56	} __packed;
	57
	58	struct mei_nfc_connect {
	59	u8 fw_ivn;
	60	u8 vendor_id;
	61	} __packed;
	62
	63	struct mei_nfc_connect_resp {
	64	u8 fw_ivn;
	65	u8 vendor_id;
	66	u16 me_major;
	67	u16 me_minor;
	68	u16 me_hotfix;
	69	u16 me_build;
	70	} __packed;
	71
	72	struct mei_nfc_hci_hdr {
4912e2fe EL	73	u8 cmd;
	74	u8 status;
	75	u16 req_id;
	76	u32 reserved;
	77	u16 data_size;
bda7eb27	78	} __packed;
4912e2fe	79
be9b720a TW	80	#define MEI_NFC_CMD_MAINTENANCE 0x00
	81	#define MEI_NFC_CMD_HCI_SEND 0x01
	82	#define MEI_NFC_CMD_HCI_RECV 0x02
	83
	84	#define MEI_NFC_SUBCMD_CONNECT 0x00
	85	#define MEI_NFC_SUBCMD_IF_VERSION 0x01
	86
	87	#define MEI_NFC_HEADER_SIZE 10
	88
	89
4912e2fe EL	90	#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
	91
	92	#define MEI_DUMP_SKB_IN(info, skb) \
	93	do { \
	94	pr_debug("%s:\n", info); \
	95	print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET, \
	96	16, 1, (skb)->data, (skb)->len, false); \
	97	} while (0)
	98
	99	#define MEI_DUMP_SKB_OUT(info, skb) \
	100	do { \
	101	pr_debug("%s:\n", info); \
	102	print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET, \
be9b720a	103	16, 1, (skb)->data, (skb)->len, false); \
4912e2fe EL	104	} while (0)
4912e2fe EL	105
be9b720a TW	106
be9b720a TW	107	static int mei_nfc_if_version(struct nfc_mei_phy *phy)
4912e2fe	108	{
be9b720a TW	109
	110	struct mei_nfc_cmd cmd;
	111	struct mei_nfc_reply *reply = NULL;
	112	struct mei_nfc_if_version *version;
	113	size_t if_version_length;
	114	int bytes_recv, r;
4912e2fe EL	115
	116	pr_info("%s\n", __func__);
	117
be9b720a TW	118	memset(&cmd, 0, sizeof(struct mei_nfc_cmd));
	119	cmd.command = MEI_NFC_CMD_MAINTENANCE;
	120	cmd.data_size = 1;
	121	cmd.sub_command = MEI_NFC_SUBCMD_IF_VERSION;
4912e2fe	122
be9b720a	123	r = mei_cl_send(phy->device, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
4912e2fe	124	if (r < 0) {
be9b720a	125	pr_err("Could not send IF version cmd\n");
bda7eb27	126	return r;
4912e2fe EL	127	}
4912e2fe EL	128
be9b720a TW	129	/* to be sure on the stack we alloc memory */
	130	if_version_length = sizeof(struct mei_nfc_reply) +
	131	sizeof(struct mei_nfc_if_version);
73f3adb9	132
be9b720a TW	133	reply = kzalloc(if_version_length, GFP_KERNEL);
	134	if (!reply)
	135	return -ENOMEM;
	136
	137	bytes_recv = mei_cl_recv(phy->device, (u8 *)reply, if_version_length);
	138	if (bytes_recv < 0 \|\| bytes_recv < sizeof(struct mei_nfc_reply)) {
	139	pr_err("Could not read IF version\n");
	140	r = -EIO;
	141	goto err;
73f3adb9 SO	142	}
73f3adb9 SO	143
be9b720a	144	version = (struct mei_nfc_if_version *)reply->data;
4912e2fe	145
be9b720a TW	146	phy->fw_ivn = version->fw_ivn;
	147	phy->vendor_id = version->vendor_id;
	148	phy->radio_type = version->radio_type;
	149
	150	err:
	151	kfree(reply);
	152	return r;
4912e2fe	153	}
4912e2fe	154
be9b720a	155	static int mei_nfc_connect(struct nfc_mei_phy *phy)
4912e2fe	156	{
be9b720a TW	157	struct mei_nfc_cmd cmd, reply;
	158	struct mei_nfc_connect *connect;
	159	struct mei_nfc_connect_resp *connect_resp;
	160	size_t connect_length, connect_resp_length;
	161	int bytes_recv, r;
4912e2fe EL	162
	163	pr_info("%s\n", __func__);
	164
be9b720a TW	165	connect_length = sizeof(struct mei_nfc_cmd) +
be9b720a TW	166	sizeof(struct mei_nfc_connect);
4912e2fe	167
be9b720a TW	168	connect_resp_length = sizeof(struct mei_nfc_cmd) +
	169	sizeof(struct mei_nfc_connect_resp);
	170
	171	cmd = kzalloc(connect_length, GFP_KERNEL);
	172	if (!cmd)
	173	return -ENOMEM;
	174	connect = (struct mei_nfc_connect *)cmd->data;
	175
	176	reply = kzalloc(connect_resp_length, GFP_KERNEL);
	177	if (!reply) {
	178	kfree(cmd);
	179	return -ENOMEM;
	180	}
	181
	182	connect_resp = (struct mei_nfc_connect_resp *)reply->data;
	183
	184	cmd->command = MEI_NFC_CMD_MAINTENANCE;
	185	cmd->data_size = 3;
	186	cmd->sub_command = MEI_NFC_SUBCMD_CONNECT;
	187	connect->fw_ivn = phy->fw_ivn;
	188	connect->vendor_id = phy->vendor_id;
	189
	190	r = mei_cl_send(phy->device, (u8 *)cmd, connect_length);
	191	if (r < 0) {
	192	pr_err("Could not send connect cmd %d\n", r);
	193	goto err;
	194	}
	195
	196	bytes_recv = mei_cl_recv(phy->device, (u8 *)reply, connect_resp_length);
	197	if (bytes_recv < 0) {
	198	r = bytes_recv;
	199	pr_err("Could not read connect response %d\n", r);
	200	goto err;
	201	}
	202
	203	pr_info("IVN 0x%x Vendor ID 0x%x\n",
	204	connect_resp->fw_ivn, connect_resp->vendor_id);
	205
	206	pr_info("ME FW %d.%d.%d.%d\n",
	207	connect_resp->me_major, connect_resp->me_minor,
	208	connect_resp->me_hotfix, connect_resp->me_build);
	209
	210	r = 0;
	211
	212	err:
	213	kfree(reply);
	214	kfree(cmd);
	215
	216	return r;
	217	}
	218
	219	static int mei_nfc_send(struct nfc_mei_phy phy, u8 buf, size_t length)
	220	{
	221	struct mei_nfc_hci_hdr *hdr;
	222	u8 *mei_buf;
	223	int err;
	224
	225	err = -ENOMEM;
	226	mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
	227	if (!mei_buf)
	228	goto out;
	229
	230	hdr = (struct mei_nfc_hci_hdr *) mei_buf;
	231	hdr->cmd = MEI_NFC_CMD_HCI_SEND;
232	hdr->status = 0;
233	hdr->req_id = phy->req_id;
234	hdr->reserved = 0;
235	hdr->data_size = length;
236
237	memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
238	err = mei_cl_send(phy->device, mei_buf, length + MEI_NFC_HEADER_SIZE);
239	if (err < 0)
240	goto out;
241
242	if (!wait_event_interruptible_timeout(phy->send_wq,
243	phy->recv_req_id == phy->req_id, HZ)) {
244	pr_err("NFC MEI command timeout\n");
245	err = -ETIME;
246	} else {
247	phy->req_id++;
248	}
249	out:
250	kfree(mei_buf);
251	return err;
4912e2fe	252	}
4912e2fe EL	253
	254	/*
	255	* Writing a frame must not return the number of written bytes.
	256	* It must return either zero for success, or <0 for error.
	257	* In addition, it must not alter the skb
	258	*/
	259	static int nfc_mei_phy_write(void phy_id, struct sk_buff skb)
	260	{
	261	struct nfc_mei_phy *phy = phy_id;
	262	int r;
	263
	264	MEI_DUMP_SKB_OUT("mei frame sent", skb);
	265
be9b720a	266	r = mei_nfc_send(phy, skb->data, skb->len);
4912e2fe EL	267	if (r > 0)
	268	r = 0;
	269
	270	return r;
	271	}
	272
be9b720a TW	273	static int mei_nfc_recv(struct nfc_mei_phy phy, u8 buf, size_t length)
	274	{
	275	struct mei_nfc_hci_hdr *hci_hdr;
	276	int received_length;
	277
	278	received_length = mei_cl_recv(phy->device, buf, length);
	279	if (received_length < 0)
	280	return received_length;
	281
	282	hci_hdr = (struct mei_nfc_hci_hdr *) buf;
	283
	284	if (hci_hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
	285	phy->recv_req_id = hci_hdr->req_id;
	286	wake_up(&phy->send_wq);
	287
	288	return 0;
	289	}
	290
	291	return received_length;
	292	}
	293
	294
	295	static void nfc_mei_event_cb(struct mei_cl_device *device, u32 events,
	296	void *context)
4912e2fe EL	297	{
	298	struct nfc_mei_phy *phy = context;
	299
	300	if (phy->hard_fault != 0)
	301	return;
	302
	303	if (events & BIT(MEI_CL_EVENT_RX)) {
	304	struct sk_buff *skb;
	305	int reply_size;
	306
	307	skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
	308	if (!skb)
	309	return;
	310
be9b720a	311	reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
4912e2fe	312	if (reply_size < MEI_NFC_HEADER_SIZE) {
fe0219cc	313	kfree_skb(skb);
4912e2fe EL	314	return;
	315	}
	316
	317	skb_put(skb, reply_size);
	318	skb_pull(skb, MEI_NFC_HEADER_SIZE);
	319
	320	MEI_DUMP_SKB_IN("mei frame read", skb);
	321
	322	nfc_hci_recv_frame(phy->hdev, skb);
	323	}
	324	}
be9b720a TW	325
	326	static int nfc_mei_phy_enable(void *phy_id)
	327	{
	328	int r;
	329	struct nfc_mei_phy *phy = phy_id;
	330
	331	pr_info("%s\n", __func__);
	332
	333	if (phy->powered == 1)
	334	return 0;
	335
	336	r = mei_cl_enable_device(phy->device);
	337	if (r < 0) {
	338	pr_err("Could not enable device %d\n", r);
	339	return r;
	340	}
	341
	342	r = mei_nfc_if_version(phy);
	343	if (r < 0) {
	344	pr_err("Could not enable device %d\n", r);
	345	goto err;
	346	}
	347
	348	r = mei_nfc_connect(phy);
	349	if (r < 0) {
	350	pr_err("Could not connect to device %d\n", r);
	351	goto err;
	352	}
	353
	354	r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy);
	355	if (r) {
	356	pr_err("Event cb registration failed %d\n", r);
	357	goto err;
	358	}
	359
	360	phy->powered = 1;
	361
	362	return 0;
	363
	364	err:
	365	phy->powered = 0;
	366	mei_cl_disable_device(phy->device);
	367	return r;
	368	}
	369
	370	static void nfc_mei_phy_disable(void *phy_id)
	371	{
	372	struct nfc_mei_phy *phy = phy_id;
	373
	374	pr_info("%s\n", __func__);
	375
	376	mei_cl_disable_device(phy->device);
	377
	378	phy->powered = 0;
	379	}
4912e2fe EL	380
	381	struct nfc_phy_ops mei_phy_ops = {
	382	.write = nfc_mei_phy_write,
	383	.enable = nfc_mei_phy_enable,
	384	.disable = nfc_mei_phy_disable,
	385	};
	386	EXPORT_SYMBOL_GPL(mei_phy_ops);
	387
	388	struct nfc_mei_phy nfc_mei_phy_alloc(struct mei_cl_device device)
	389	{
	390	struct nfc_mei_phy *phy;
	391
	392	phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
	393	if (!phy)
	394	return NULL;
	395
	396	phy->device = device;
be9b720a	397	init_waitqueue_head(&phy->send_wq);
4912e2fe EL	398	mei_cl_set_drvdata(device, phy);
	399
	400	return phy;
	401	}
	402	EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
	403
	404	void nfc_mei_phy_free(struct nfc_mei_phy *phy)
	405	{
be9b720a	406	mei_cl_disable_device(phy->device);
4912e2fe EL	407	kfree(phy);
	408	}
	409	EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
	410
	411	MODULE_LICENSE("GPL");
	412	MODULE_DESCRIPTION("mei bus NFC device interface");