[deliverable/linux.git] / net / nfc / nci / spi.c

/*
 * 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 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#define pr_fmt(fmt) "nci_spi: %s: " fmt, __func__

#include <linux/module.h>

#include <linux/export.h>
#include <linux/spi/spi.h>
#include <linux/crc-ccitt.h>
#include <net/nfc/nci_core.h>

#define NCI_SPI_ACK_SHIFT		6
#define NCI_SPI_MSB_PAYLOAD_MASK	0x3F

#define NCI_SPI_SEND_TIMEOUT	(NCI_CMD_TIMEOUT > NCI_DATA_TIMEOUT ? \
					NCI_CMD_TIMEOUT : NCI_DATA_TIMEOUT)

#define NCI_SPI_DIRECT_WRITE	0x01
#define NCI_SPI_DIRECT_READ	0x02

#define ACKNOWLEDGE_NONE	0
#define ACKNOWLEDGE_ACK		1
#define ACKNOWLEDGE_NACK	2

#define CRC_INIT		0xFFFF

static int __nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb,
			  int cs_change)
{
	struct spi_message m;
	struct spi_transfer t;

	memset(&t, 0, sizeof(struct spi_transfer));
	/* a NULL skb means we just want the SPI chip select line to raise */
	if (skb) {
		t.tx_buf = skb->data;
		t.len = skb->len;
	} else {
		/* still set tx_buf non NULL to make the driver happy */
		t.tx_buf = &t;
		t.len = 0;
	}
	t.cs_change = cs_change;
	t.delay_usecs = nspi->xfer_udelay;

	spi_message_init(&m);
	spi_message_add_tail(&t, &m);

	return spi_sync(nspi->spi, &m);
}

int nci_spi_send(struct nci_spi *nspi,
		 struct completion *write_handshake_completion,
		 struct sk_buff *skb)
{
	unsigned int payload_len = skb->len;
	unsigned char *hdr;
	int ret;
	long completion_rc;

	/* add the NCI SPI header to the start of the buffer */
	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	hdr[0] = NCI_SPI_DIRECT_WRITE;
	hdr[1] = nspi->acknowledge_mode;
	hdr[2] = payload_len >> 8;
	hdr[3] = payload_len & 0xFF;

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
		u16 crc;

		crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
		*skb_put(skb, 1) = crc >> 8;
		*skb_put(skb, 1) = crc & 0xFF;
	}

	if (write_handshake_completion)	{
		/* Trick SPI driver to raise chip select */
		ret = __nci_spi_send(nspi, NULL, 1);
		if (ret)
			goto done;

		/* wait for NFC chip hardware handshake to complete */
		if (wait_for_completion_timeout(write_handshake_completion,
						msecs_to_jiffies(1000)) == 0) {
			ret = -ETIME;
			goto done;
		}
	}

	ret = __nci_spi_send(nspi, skb, 0);
	if (ret != 0 || nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)
		goto done;

	reinit_completion(&nspi->req_completion);
	completion_rc =	wait_for_completion_interruptible_timeout(
							&nspi->req_completion,
							NCI_SPI_SEND_TIMEOUT);

	if (completion_rc <= 0 || nspi->req_result == ACKNOWLEDGE_NACK)
		ret = -EIO;

done:
	kfree_skb(skb);

	return ret;
}
EXPORT_SYMBOL_GPL(nci_spi_send);

/* ---- Interface to NCI SPI drivers ---- */

/**
 * nci_spi_allocate_spi - allocate a new nci spi
 *
 * @spi: SPI device
 * @acknowledge_mode: Acknowledge mode used by the NFC device
 * @delay: delay between transactions in us
 * @ndev: nci dev to send incoming nci frames to
 */
struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,
				     u8 acknowledge_mode, unsigned int delay,
				     struct nci_dev *ndev)
{
	struct nci_spi *nspi;

	nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
	if (!nspi)
		return NULL;

	nspi->acknowledge_mode = acknowledge_mode;
	nspi->xfer_udelay = delay;

	nspi->spi = spi;
	nspi->ndev = ndev;
	init_completion(&nspi->req_completion);

	return nspi;
}
EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);

static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
{
	struct sk_buff *skb;
	unsigned char *hdr;
	u16 crc;
	int ret;

	skb = nci_skb_alloc(nspi->ndev, 0, GFP_KERNEL);

	/* add the NCI SPI header to the start of the buffer */
	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	hdr[0] = NCI_SPI_DIRECT_WRITE;
	hdr[1] = NCI_SPI_CRC_ENABLED;
	hdr[2] = acknowledge << NCI_SPI_ACK_SHIFT;
	hdr[3] = 0;

	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
	*skb_put(skb, 1) = crc >> 8;
	*skb_put(skb, 1) = crc & 0xFF;

	ret = __nci_spi_send(nspi, skb, 0);

	kfree_skb(skb);

	return ret;
}

static struct sk_buff *__nci_spi_read(struct nci_spi *nspi)
{
	struct sk_buff *skb;
	struct spi_message m;
	unsigned char req[2], resp_hdr[2];
	struct spi_transfer tx, rx;
	unsigned short rx_len = 0;
	int ret;

	spi_message_init(&m);

	memset(&tx, 0, sizeof(struct spi_transfer));
	req[0] = NCI_SPI_DIRECT_READ;
	req[1] = nspi->acknowledge_mode;
	tx.tx_buf = req;
	tx.len = 2;
	tx.cs_change = 0;
	spi_message_add_tail(&tx, &m);

	memset(&rx, 0, sizeof(struct spi_transfer));
	rx.rx_buf = resp_hdr;
	rx.len = 2;
	rx.cs_change = 1;
	spi_message_add_tail(&rx, &m);

	ret = spi_sync(nspi->spi, &m);
	if (ret)
		return NULL;

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
		rx_len = ((resp_hdr[0] & NCI_SPI_MSB_PAYLOAD_MASK) << 8) +
				resp_hdr[1] + NCI_SPI_CRC_LEN;
	else
		rx_len = (resp_hdr[0] << 8) | resp_hdr[1];

	skb = nci_skb_alloc(nspi->ndev, rx_len, GFP_KERNEL);
	if (!skb)
		return NULL;

	spi_message_init(&m);

	memset(&rx, 0, sizeof(struct spi_transfer));
	rx.rx_buf = skb_put(skb, rx_len);
	rx.len = rx_len;
	rx.cs_change = 0;
	rx.delay_usecs = nspi->xfer_udelay;
	spi_message_add_tail(&rx, &m);

	ret = spi_sync(nspi->spi, &m);
	if (ret)
		goto receive_error;

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
		*skb_push(skb, 1) = resp_hdr[1];
		*skb_push(skb, 1) = resp_hdr[0];
	}

	return skb;

receive_error:
	kfree_skb(skb);

	return NULL;
}

static int nci_spi_check_crc(struct sk_buff *skb)
{
	u16 crc_data = (skb->data[skb->len - 2] << 8) |
			skb->data[skb->len - 1];
	int ret;

	ret = (crc_ccitt(CRC_INIT, skb->data, skb->len - NCI_SPI_CRC_LEN)
			== crc_data);

	skb_trim(skb, skb->len - NCI_SPI_CRC_LEN);

	return ret;
}

static u8 nci_spi_get_ack(struct sk_buff *skb)
{
	u8 ret;

	ret = skb->data[0] >> NCI_SPI_ACK_SHIFT;

	/* Remove NFCC part of the header: ACK, NACK and MSB payload len */
	skb_pull(skb, 2);

	return ret;
}

/**
 * nci_spi_read - read frame from NCI SPI drivers
 *
 * @nspi: The nci spi
 * Context: can sleep
 *
 * This call may only be used from a context that may sleep.  The sleep
 * is non-interruptible, and has no timeout.
 *
 * It returns an allocated skb containing the frame on success, or NULL.
 */
struct sk_buff *nci_spi_read(struct nci_spi *nspi)
{
	struct sk_buff *skb;

	/* Retrieve frame from SPI */
	skb = __nci_spi_read(nspi);
	if (!skb)
		goto done;

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
		if (!nci_spi_check_crc(skb)) {
			send_acknowledge(nspi, ACKNOWLEDGE_NACK);
			goto done;
		}

		/* In case of acknowledged mode: if ACK or NACK received,
		 * unblock completion of latest frame sent.
		 */
		nspi->req_result = nci_spi_get_ack(skb);
		if (nspi->req_result)
			complete(&nspi->req_completion);
	}

	/* If there is no payload (ACK/NACK only frame),
	 * free the socket buffer
	 */
	if (!skb->len) {
		kfree_skb(skb);
		skb = NULL;
		goto done;
	}

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
		send_acknowledge(nspi, ACKNOWLEDGE_ACK);

done:

	return skb;
}
EXPORT_SYMBOL_GPL(nci_spi_read);

MODULE_LICENSE("GPL");
Commit	Line	Data
8a00a61b FD	1	/*
	2	* Copyright (C) 2013 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms and conditions of the GNU General Public License,
	6	* version 2, as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	16	*
	17	*/
	18
	19	#define pr_fmt(fmt) "nci_spi: %s: " fmt, __func__
	20
fcd9d046 VC	21	#include <linux/module.h>
fcd9d046 VC	22
8a00a61b FD	23	#include <linux/export.h>
8a00a61b FD	24	#include <linux/spi/spi.h>
ee9596d4	25	#include <linux/crc-ccitt.h>
8a00a61b FD	26	#include <net/nfc/nci_core.h>
8a00a61b FD	27
391d8a2d FD	28	#define NCI_SPI_ACK_SHIFT 6
391d8a2d FD	29	#define NCI_SPI_MSB_PAYLOAD_MASK 0x3F
8a00a61b	30
ee9596d4 FD	31	#define NCI_SPI_SEND_TIMEOUT (NCI_CMD_TIMEOUT > NCI_DATA_TIMEOUT ? \
	32	NCI_CMD_TIMEOUT : NCI_DATA_TIMEOUT)
	33
	34	#define NCI_SPI_DIRECT_WRITE 0x01
	35	#define NCI_SPI_DIRECT_READ 0x02
	36
	37	#define ACKNOWLEDGE_NONE 0
	38	#define ACKNOWLEDGE_ACK 1
	39	#define ACKNOWLEDGE_NACK 2
	40
	41	#define CRC_INIT 0xFFFF
	42
2bed2785 EL	43	static int __nci_spi_send(struct nci_spi nspi, struct sk_buff skb,
2bed2785 EL	44	int cs_change)
ee9596d4 FD	45	{
	46	struct spi_message m;
	47	struct spi_transfer t;
	48
a4ada6ca	49	memset(&t, 0, sizeof(struct spi_transfer));
2bed2785 EL	50	/* a NULL skb means we just want the SPI chip select line to raise */
	51	if (skb) {
	52	t.tx_buf = skb->data;
	53	t.len = skb->len;
	54	} else {
	55	/* still set tx_buf non NULL to make the driver happy */
	56	t.tx_buf = &t;
	57	t.len = 0;
	58	}
	59	t.cs_change = cs_change;
fa544fff	60	t.delay_usecs = nspi->xfer_udelay;
ee9596d4 FD	61
	62	spi_message_init(&m);
	63	spi_message_add_tail(&t, &m);
	64
fa544fff	65	return spi_sync(nspi->spi, &m);
ee9596d4 FD	66	}
ee9596d4 FD	67
2bed2785 EL	68	int nci_spi_send(struct nci_spi *nspi,
	69	struct completion *write_handshake_completion,
	70	struct sk_buff *skb)
8a00a61b	71	{
ee9596d4 FD	72	unsigned int payload_len = skb->len;
	73	unsigned char *hdr;
	74	int ret;
	75	long completion_rc;
	76
ee9596d4 FD	77	/* add the NCI SPI header to the start of the buffer */
	78	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	79	hdr[0] = NCI_SPI_DIRECT_WRITE;
fa544fff	80	hdr[1] = nspi->acknowledge_mode;
ee9596d4 FD	81	hdr[2] = payload_len >> 8;
	82	hdr[3] = payload_len & 0xFF;
	83
fa544fff	84	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
ee9596d4 FD	85	u16 crc;
	86
	87	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
	88	*skb_put(skb, 1) = crc >> 8;
	89	*skb_put(skb, 1) = crc & 0xFF;
	90	}
	91
2bed2785 EL	92	if (write_handshake_completion) {
	93	/* Trick SPI driver to raise chip select */
	94	ret = __nci_spi_send(nspi, NULL, 1);
	95	if (ret)
	96	goto done;
ee9596d4	97
2bed2785 EL	98	/* wait for NFC chip hardware handshake to complete */
	99	if (wait_for_completion_timeout(write_handshake_completion,
	100	msecs_to_jiffies(1000)) == 0) {
	101	ret = -ETIME;
	102	goto done;
	103	}
	104	}
ee9596d4	105
2bed2785	106	ret = __nci_spi_send(nspi, skb, 0);
fa544fff	107	if (ret != 0 \|\| nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)
ee9596d4 FD	108	goto done;
ee9596d4 FD	109
9bec44bf	110	reinit_completion(&nspi->req_completion);
d5937511	111	completion_rc = wait_for_completion_interruptible_timeout(
fa544fff	112	&nspi->req_completion,
d5937511	113	NCI_SPI_SEND_TIMEOUT);
ee9596d4	114
fa544fff	115	if (completion_rc <= 0 \|\| nspi->req_result == ACKNOWLEDGE_NACK)
ee9596d4 FD	116	ret = -EIO;
	117
	118	done:
2bed2785 EL	119	kfree_skb(skb);
2bed2785 EL	120
ee9596d4	121	return ret;
8a00a61b	122	}
fa544fff	123	EXPORT_SYMBOL_GPL(nci_spi_send);
8a00a61b FD	124
	125	/* ---- Interface to NCI SPI drivers ---- */
	126
	127	/**
fa544fff	128	* nci_spi_allocate_spi - allocate a new nci spi
8a00a61b FD	129	*
8a00a61b FD	130	* @spi: SPI device
fa544fff	131	* @acknowledge_mode: Acknowledge mode used by the NFC device
8a00a61b	132	* @delay: delay between transactions in us
fa544fff	133	* @ndev: nci dev to send incoming nci frames to
8a00a61b	134	*/
fa544fff	135	struct nci_spi nci_spi_allocate_spi(struct spi_device spi,
fa544fff EL	136	u8 acknowledge_mode, unsigned int delay,
fa544fff EL	137	struct nci_dev *ndev)
8a00a61b	138	{
fa544fff	139	struct nci_spi *nspi;
8a00a61b	140
fa544fff EL	141	nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
fa544fff EL	142	if (!nspi)
8a00a61b FD	143	return NULL;
8a00a61b FD	144
fa544fff EL	145	nspi->acknowledge_mode = acknowledge_mode;
fa544fff EL	146	nspi->xfer_udelay = delay;
8a00a61b	147
645d5087	148	nspi->spi = spi;
fa544fff	149	nspi->ndev = ndev;
9bec44bf	150	init_completion(&nspi->req_completion);
8a00a61b	151
fa544fff	152	return nspi;
8a00a61b	153	}
fa544fff	154	EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);
391d8a2d	155
fa544fff	156	static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
391d8a2d FD	157	{
	158	struct sk_buff *skb;
	159	unsigned char *hdr;
	160	u16 crc;
	161	int ret;
	162
fa544fff	163	skb = nci_skb_alloc(nspi->ndev, 0, GFP_KERNEL);
391d8a2d FD	164
	165	/* add the NCI SPI header to the start of the buffer */
	166	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	167	hdr[0] = NCI_SPI_DIRECT_WRITE;
	168	hdr[1] = NCI_SPI_CRC_ENABLED;
	169	hdr[2] = acknowledge << NCI_SPI_ACK_SHIFT;
	170	hdr[3] = 0;
	171
	172	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
	173	*skb_put(skb, 1) = crc >> 8;
	174	*skb_put(skb, 1) = crc & 0xFF;
	175
2bed2785	176	ret = __nci_spi_send(nspi, skb, 0);
391d8a2d FD	177
	178	kfree_skb(skb);
	179
	180	return ret;
	181	}
	182
22d4aae5	183	static struct sk_buff __nci_spi_read(struct nci_spi nspi)
391d8a2d FD	184	{
	185	struct sk_buff *skb;
	186	struct spi_message m;
	187	unsigned char req[2], resp_hdr[2];
	188	struct spi_transfer tx, rx;
	189	unsigned short rx_len = 0;
	190	int ret;
	191
	192	spi_message_init(&m);
a4ada6ca EL	193
a4ada6ca EL	194	memset(&tx, 0, sizeof(struct spi_transfer));
391d8a2d	195	req[0] = NCI_SPI_DIRECT_READ;
fa544fff	196	req[1] = nspi->acknowledge_mode;
391d8a2d FD	197	tx.tx_buf = req;
	198	tx.len = 2;
	199	tx.cs_change = 0;
	200	spi_message_add_tail(&tx, &m);
a4ada6ca EL	201
a4ada6ca EL	202	memset(&rx, 0, sizeof(struct spi_transfer));
391d8a2d FD	203	rx.rx_buf = resp_hdr;
	204	rx.len = 2;
	205	rx.cs_change = 1;
	206	spi_message_add_tail(&rx, &m);
a4ada6ca	207
fa544fff	208	ret = spi_sync(nspi->spi, &m);
391d8a2d FD	209	if (ret)
	210	return NULL;
	211
fa544fff	212	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
391d8a2d FD	213	rx_len = ((resp_hdr[0] & NCI_SPI_MSB_PAYLOAD_MASK) << 8) +
	214	resp_hdr[1] + NCI_SPI_CRC_LEN;
	215	else
	216	rx_len = (resp_hdr[0] << 8) \| resp_hdr[1];
	217
fa544fff	218	skb = nci_skb_alloc(nspi->ndev, rx_len, GFP_KERNEL);
391d8a2d FD	219	if (!skb)
	220	return NULL;
	221
	222	spi_message_init(&m);
a4ada6ca EL	223
a4ada6ca EL	224	memset(&rx, 0, sizeof(struct spi_transfer));
391d8a2d FD	225	rx.rx_buf = skb_put(skb, rx_len);
	226	rx.len = rx_len;
	227	rx.cs_change = 0;
fa544fff	228	rx.delay_usecs = nspi->xfer_udelay;
391d8a2d	229	spi_message_add_tail(&rx, &m);
a4ada6ca	230
fa544fff	231	ret = spi_sync(nspi->spi, &m);
391d8a2d FD	232	if (ret)
	233	goto receive_error;
	234
fa544fff	235	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
391d8a2d FD	236	*skb_push(skb, 1) = resp_hdr[1];
	237	*skb_push(skb, 1) = resp_hdr[0];
	238	}
	239
	240	return skb;
	241
	242	receive_error:
	243	kfree_skb(skb);
	244
	245	return NULL;
	246	}
	247
	248	static int nci_spi_check_crc(struct sk_buff *skb)
	249	{
	250	u16 crc_data = (skb->data[skb->len - 2] << 8) \|
	251	skb->data[skb->len - 1];
	252	int ret;
	253
	254	ret = (crc_ccitt(CRC_INIT, skb->data, skb->len - NCI_SPI_CRC_LEN)
	255	== crc_data);
	256
	257	skb_trim(skb, skb->len - NCI_SPI_CRC_LEN);
	258
	259	return ret;
	260	}
	261
	262	static u8 nci_spi_get_ack(struct sk_buff *skb)
	263	{
	264	u8 ret;
	265
	266	ret = skb->data[0] >> NCI_SPI_ACK_SHIFT;
	267
	268	/* Remove NFCC part of the header: ACK, NACK and MSB payload len */
	269	skb_pull(skb, 2);
	270
	271	return ret;
	272	}
	273
	274	/**
22d4aae5	275	* nci_spi_read - read frame from NCI SPI drivers
391d8a2d	276	*
fa544fff	277	* @nspi: The nci spi
391d8a2d FD	278	* Context: can sleep
	279	*
	280	* This call may only be used from a context that may sleep. The sleep
	281	* is non-interruptible, and has no timeout.
	282	*
22d4aae5	283	* It returns an allocated skb containing the frame on success, or NULL.
391d8a2d	284	*/
22d4aae5	285	struct sk_buff nci_spi_read(struct nci_spi nspi)
391d8a2d FD	286	{
391d8a2d FD	287	struct sk_buff *skb;
391d8a2d	288
391d8a2d	289	/* Retrieve frame from SPI */
22d4aae5 EL	290	skb = __nci_spi_read(nspi);
22d4aae5 EL	291	if (!skb)
391d8a2d	292	goto done;
391d8a2d	293
fa544fff	294	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
391d8a2d	295	if (!nci_spi_check_crc(skb)) {
fa544fff	296	send_acknowledge(nspi, ACKNOWLEDGE_NACK);
391d8a2d FD	297	goto done;
	298	}
	299
	300	/* In case of acknowledged mode: if ACK or NACK received,
	301	* unblock completion of latest frame sent.
	302	*/
fa544fff EL	303	nspi->req_result = nci_spi_get_ack(skb);
	304	if (nspi->req_result)
	305	complete(&nspi->req_completion);
391d8a2d FD	306	}
	307
	308	/* If there is no payload (ACK/NACK only frame),
	309	* free the socket buffer
	310	*/
22d4aae5	311	if (!skb->len) {
391d8a2d	312	kfree_skb(skb);
22d4aae5	313	skb = NULL;
391d8a2d FD	314	goto done;
	315	}
	316
fa544fff EL	317	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
fa544fff EL	318	send_acknowledge(nspi, ACKNOWLEDGE_ACK);
391d8a2d	319
391d8a2d	320	done:
391d8a2d	321
22d4aae5	322	return skb;
391d8a2d	323	}
22d4aae5	324	EXPORT_SYMBOL_GPL(nci_spi_read);
fcd9d046 VC	325
fcd9d046 VC	326	MODULE_LICENSE("GPL");