[linux-2.6-block.git] / net / nfc / nci / spi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013  Intel Corporation. All rights reserved.
 */

#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.value = nspi->xfer_udelay;
	t.delay.unit = SPI_DELAY_UNIT_USECS;
	t.speed_hz = nspi->xfer_speed_hz;

	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_u8(skb, crc >> 8);
		skb_put_u8(skb, 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;
	/* Use controller max SPI speed by default */
	nspi->xfer_speed_hz = 0;
	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_u8(skb, crc >> 8);
	skb_put_u8(skb, 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;
	tx.speed_hz = nspi->xfer_speed_hz;
	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;
	rx.speed_hz = nspi->xfer_speed_hz;
	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.value = nspi->xfer_udelay;
	rx.delay.unit = SPI_DELAY_UNIT_USECS;
	rx.speed_hz = nspi->xfer_speed_hz;
	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) {
		*(u8 *)skb_push(skb, 1) = resp_hdr[1];
		*(u8 *)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
a61127c2	1	// SPDX-License-Identifier: GPL-2.0-only
8a00a61b FD	2	/*
8a00a61b FD	3	* Copyright (C) 2013 Intel Corporation. All rights reserved.
8a00a61b FD	4	*/
	5
	6	#define pr_fmt(fmt) "nci_spi: %s: " fmt, __func__
	7
fcd9d046 VC	8	#include <linux/module.h>
fcd9d046 VC	9
8a00a61b FD	10	#include <linux/export.h>
8a00a61b FD	11	#include <linux/spi/spi.h>
ee9596d4	12	#include <linux/crc-ccitt.h>
8a00a61b FD	13	#include <net/nfc/nci_core.h>
8a00a61b FD	14
391d8a2d FD	15	#define NCI_SPI_ACK_SHIFT 6
391d8a2d FD	16	#define NCI_SPI_MSB_PAYLOAD_MASK 0x3F
8a00a61b	17
ee9596d4 FD	18	#define NCI_SPI_SEND_TIMEOUT (NCI_CMD_TIMEOUT > NCI_DATA_TIMEOUT ? \
	19	NCI_CMD_TIMEOUT : NCI_DATA_TIMEOUT)
	20
	21	#define NCI_SPI_DIRECT_WRITE 0x01
	22	#define NCI_SPI_DIRECT_READ 0x02
	23
	24	#define ACKNOWLEDGE_NONE 0
	25	#define ACKNOWLEDGE_ACK 1
	26	#define ACKNOWLEDGE_NACK 2
	27
	28	#define CRC_INIT 0xFFFF
	29
2bed2785 EL	30	static int __nci_spi_send(struct nci_spi nspi, struct sk_buff skb,
2bed2785 EL	31	int cs_change)
ee9596d4 FD	32	{
	33	struct spi_message m;
	34	struct spi_transfer t;
	35
a4ada6ca	36	memset(&t, 0, sizeof(struct spi_transfer));
2bed2785 EL	37	/* a NULL skb means we just want the SPI chip select line to raise */
	38	if (skb) {
	39	t.tx_buf = skb->data;
	40	t.len = skb->len;
	41	} else {
	42	/* still set tx_buf non NULL to make the driver happy */
	43	t.tx_buf = &t;
	44	t.len = 0;
	45	}
	46	t.cs_change = cs_change;
099ffd7e AA	47	t.delay.value = nspi->xfer_udelay;
099ffd7e AA	48	t.delay.unit = SPI_DELAY_UNIT_USECS;
2bd83245	49	t.speed_hz = nspi->xfer_speed_hz;
ee9596d4 FD	50
	51	spi_message_init(&m);
	52	spi_message_add_tail(&t, &m);
	53
fa544fff	54	return spi_sync(nspi->spi, &m);
ee9596d4 FD	55	}
ee9596d4 FD	56
2bed2785 EL	57	int nci_spi_send(struct nci_spi *nspi,
	58	struct completion *write_handshake_completion,
	59	struct sk_buff *skb)
8a00a61b	60	{
ee9596d4 FD	61	unsigned int payload_len = skb->len;
	62	unsigned char *hdr;
	63	int ret;
	64	long completion_rc;
	65
ee9596d4 FD	66	/* add the NCI SPI header to the start of the buffer */
	67	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	68	hdr[0] = NCI_SPI_DIRECT_WRITE;
fa544fff	69	hdr[1] = nspi->acknowledge_mode;
ee9596d4 FD	70	hdr[2] = payload_len >> 8;
	71	hdr[3] = payload_len & 0xFF;
	72
fa544fff	73	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
ee9596d4 FD	74	u16 crc;
	75
	76	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
634fef61 JB	77	skb_put_u8(skb, crc >> 8);
634fef61 JB	78	skb_put_u8(skb, crc & 0xFF);
ee9596d4 FD	79	}
ee9596d4 FD	80
2bed2785 EL	81	if (write_handshake_completion) {
	82	/* Trick SPI driver to raise chip select */
	83	ret = __nci_spi_send(nspi, NULL, 1);
	84	if (ret)
	85	goto done;
ee9596d4	86
2bed2785 EL	87	/* wait for NFC chip hardware handshake to complete */
	88	if (wait_for_completion_timeout(write_handshake_completion,
	89	msecs_to_jiffies(1000)) == 0) {
	90	ret = -ETIME;
	91	goto done;
	92	}
	93	}
ee9596d4	94
2bed2785	95	ret = __nci_spi_send(nspi, skb, 0);
fa544fff	96	if (ret != 0 \|\| nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)
ee9596d4 FD	97	goto done;
ee9596d4 FD	98
9bec44bf	99	reinit_completion(&nspi->req_completion);
d5937511	100	completion_rc = wait_for_completion_interruptible_timeout(
fa544fff	101	&nspi->req_completion,
d5937511	102	NCI_SPI_SEND_TIMEOUT);
ee9596d4	103
fa544fff	104	if (completion_rc <= 0 \|\| nspi->req_result == ACKNOWLEDGE_NACK)
ee9596d4 FD	105	ret = -EIO;
	106
	107	done:
2bed2785 EL	108	kfree_skb(skb);
2bed2785 EL	109
ee9596d4	110	return ret;
8a00a61b	111	}
fa544fff	112	EXPORT_SYMBOL_GPL(nci_spi_send);
8a00a61b FD	113
	114	/* ---- Interface to NCI SPI drivers ---- */
	115
	116	/**
fa544fff	117	* nci_spi_allocate_spi - allocate a new nci spi
8a00a61b FD	118	*
8a00a61b FD	119	* @spi: SPI device
fa544fff	120	* @acknowledge_mode: Acknowledge mode used by the NFC device
8a00a61b	121	* @delay: delay between transactions in us
fa544fff	122	* @ndev: nci dev to send incoming nci frames to
8a00a61b	123	*/
fa544fff	124	struct nci_spi nci_spi_allocate_spi(struct spi_device spi,
fa544fff EL	125	u8 acknowledge_mode, unsigned int delay,
fa544fff EL	126	struct nci_dev *ndev)
8a00a61b	127	{
fa544fff	128	struct nci_spi *nspi;
8a00a61b	129
fa544fff EL	130	nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
fa544fff EL	131	if (!nspi)
8a00a61b FD	132	return NULL;
8a00a61b FD	133
fa544fff EL	134	nspi->acknowledge_mode = acknowledge_mode;
fa544fff EL	135	nspi->xfer_udelay = delay;
2bd83245 VC	136	/* Use controller max SPI speed by default */
2bd83245 VC	137	nspi->xfer_speed_hz = 0;
645d5087	138	nspi->spi = spi;
fa544fff	139	nspi->ndev = ndev;
9bec44bf	140	init_completion(&nspi->req_completion);
8a00a61b	141
fa544fff	142	return nspi;
8a00a61b	143	}
fa544fff	144	EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);
391d8a2d	145
fa544fff	146	static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
391d8a2d FD	147	{
	148	struct sk_buff *skb;
	149	unsigned char *hdr;
	150	u16 crc;
	151	int ret;
	152
fa544fff	153	skb = nci_skb_alloc(nspi->ndev, 0, GFP_KERNEL);
391d8a2d FD	154
	155	/* add the NCI SPI header to the start of the buffer */
	156	hdr = skb_push(skb, NCI_SPI_HDR_LEN);
	157	hdr[0] = NCI_SPI_DIRECT_WRITE;
	158	hdr[1] = NCI_SPI_CRC_ENABLED;
	159	hdr[2] = acknowledge << NCI_SPI_ACK_SHIFT;
	160	hdr[3] = 0;
	161
	162	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
634fef61 JB	163	skb_put_u8(skb, crc >> 8);
634fef61 JB	164	skb_put_u8(skb, crc & 0xFF);
391d8a2d	165
2bed2785	166	ret = __nci_spi_send(nspi, skb, 0);
391d8a2d FD	167
	168	kfree_skb(skb);
	169
	170	return ret;
	171	}
	172
22d4aae5	173	static struct sk_buff __nci_spi_read(struct nci_spi nspi)
391d8a2d FD	174	{
	175	struct sk_buff *skb;
	176	struct spi_message m;
	177	unsigned char req[2], resp_hdr[2];
	178	struct spi_transfer tx, rx;
	179	unsigned short rx_len = 0;
	180	int ret;
	181
	182	spi_message_init(&m);
a4ada6ca EL	183
a4ada6ca EL	184	memset(&tx, 0, sizeof(struct spi_transfer));
391d8a2d	185	req[0] = NCI_SPI_DIRECT_READ;
fa544fff	186	req[1] = nspi->acknowledge_mode;
391d8a2d FD	187	tx.tx_buf = req;
	188	tx.len = 2;
	189	tx.cs_change = 0;
2bd83245	190	tx.speed_hz = nspi->xfer_speed_hz;
391d8a2d	191	spi_message_add_tail(&tx, &m);
a4ada6ca EL	192
a4ada6ca EL	193	memset(&rx, 0, sizeof(struct spi_transfer));
391d8a2d FD	194	rx.rx_buf = resp_hdr;
	195	rx.len = 2;
	196	rx.cs_change = 1;
2bd83245	197	rx.speed_hz = nspi->xfer_speed_hz;
391d8a2d	198	spi_message_add_tail(&rx, &m);
a4ada6ca	199
fa544fff	200	ret = spi_sync(nspi->spi, &m);
391d8a2d FD	201	if (ret)
	202	return NULL;
	203
fa544fff	204	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
391d8a2d FD	205	rx_len = ((resp_hdr[0] & NCI_SPI_MSB_PAYLOAD_MASK) << 8) +
	206	resp_hdr[1] + NCI_SPI_CRC_LEN;
	207	else
	208	rx_len = (resp_hdr[0] << 8) \| resp_hdr[1];
	209
fa544fff	210	skb = nci_skb_alloc(nspi->ndev, rx_len, GFP_KERNEL);
391d8a2d FD	211	if (!skb)
	212	return NULL;
	213
	214	spi_message_init(&m);
a4ada6ca EL	215
a4ada6ca EL	216	memset(&rx, 0, sizeof(struct spi_transfer));
391d8a2d FD	217	rx.rx_buf = skb_put(skb, rx_len);
	218	rx.len = rx_len;
	219	rx.cs_change = 0;
099ffd7e AA	220	rx.delay.value = nspi->xfer_udelay;
099ffd7e AA	221	rx.delay.unit = SPI_DELAY_UNIT_USECS;
2bd83245	222	rx.speed_hz = nspi->xfer_speed_hz;
391d8a2d	223	spi_message_add_tail(&rx, &m);
a4ada6ca	224
fa544fff	225	ret = spi_sync(nspi->spi, &m);
391d8a2d FD	226	if (ret)
	227	goto receive_error;
	228
fa544fff	229	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
d58ff351 JB	230	(u8 )skb_push(skb, 1) = resp_hdr[1];
d58ff351 JB	231	(u8 )skb_push(skb, 1) = resp_hdr[0];
391d8a2d FD	232	}
	233
	234	return skb;
	235
	236	receive_error:
	237	kfree_skb(skb);
	238
	239	return NULL;
	240	}
	241
	242	static int nci_spi_check_crc(struct sk_buff *skb)
	243	{
	244	u16 crc_data = (skb->data[skb->len - 2] << 8) \|
	245	skb->data[skb->len - 1];
	246	int ret;
	247
	248	ret = (crc_ccitt(CRC_INIT, skb->data, skb->len - NCI_SPI_CRC_LEN)
	249	== crc_data);
	250
	251	skb_trim(skb, skb->len - NCI_SPI_CRC_LEN);
	252
	253	return ret;
	254	}
	255
	256	static u8 nci_spi_get_ack(struct sk_buff *skb)
	257	{
	258	u8 ret;
	259
	260	ret = skb->data[0] >> NCI_SPI_ACK_SHIFT;
	261
	262	/* Remove NFCC part of the header: ACK, NACK and MSB payload len */
	263	skb_pull(skb, 2);
	264
	265	return ret;
	266	}
	267
	268	/**
22d4aae5	269	* nci_spi_read - read frame from NCI SPI drivers
391d8a2d	270	*
fa544fff	271	* @nspi: The nci spi
391d8a2d FD	272	* Context: can sleep
	273	*
	274	* This call may only be used from a context that may sleep. The sleep
	275	* is non-interruptible, and has no timeout.
	276	*
22d4aae5	277	* It returns an allocated skb containing the frame on success, or NULL.
391d8a2d	278	*/
22d4aae5	279	struct sk_buff nci_spi_read(struct nci_spi nspi)
391d8a2d FD	280	{
391d8a2d FD	281	struct sk_buff *skb;
391d8a2d	282
391d8a2d	283	/* Retrieve frame from SPI */
22d4aae5 EL	284	skb = __nci_spi_read(nspi);
22d4aae5 EL	285	if (!skb)
391d8a2d	286	goto done;
391d8a2d	287
fa544fff	288	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
391d8a2d	289	if (!nci_spi_check_crc(skb)) {
fa544fff	290	send_acknowledge(nspi, ACKNOWLEDGE_NACK);
391d8a2d FD	291	goto done;
	292	}
	293
	294	/* In case of acknowledged mode: if ACK or NACK received,
	295	* unblock completion of latest frame sent.
	296	*/
fa544fff EL	297	nspi->req_result = nci_spi_get_ack(skb);
	298	if (nspi->req_result)
	299	complete(&nspi->req_completion);
391d8a2d FD	300	}
	301
	302	/* If there is no payload (ACK/NACK only frame),
	303	* free the socket buffer
	304	*/
22d4aae5	305	if (!skb->len) {
391d8a2d	306	kfree_skb(skb);
22d4aae5	307	skb = NULL;
391d8a2d FD	308	goto done;
	309	}
	310
fa544fff EL	311	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
fa544fff EL	312	send_acknowledge(nspi, ACKNOWLEDGE_ACK);
391d8a2d	313
391d8a2d	314	done:
391d8a2d	315
22d4aae5	316	return skb;
391d8a2d	317	}
22d4aae5	318	EXPORT_SYMBOL_GPL(nci_spi_read);
fcd9d046 VC	319
fcd9d046 VC	320	MODULE_LICENSE("GPL");