Commit fa544fff authored by Eric Lapuyade's avatar Eric Lapuyade Committed by Samuel Ortiz
Browse files

NFC: NCI: Simplify NCI SPI to become a simple framing/checking layer 



NCI SPI layer should not manage the nci dev, this is the job of the nci
chipset driver. This layer should be limited to frame/deframe nci
packets, and optionnaly check integrity (crc) and manage the ack/nak
protocol.

The NCI SPI must not be mixed up with an NCI dev. spi_[dev|device] are
therefore renamed to a simple spi for more clarity.
The header and crc sizes are moved to nci.h so that drivers can use
them to reserve space in outgoing skbs.
nci_spi_send() is exported to be accessible by drivers.

Signed-off-by: default avatarEric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 08f13acf

include/net/nfc/nci.h

+4 −0
Original line number Diff line number Diff line
@@ -166,6 +166,10 @@ 
#define NCI_GID_NFCEE_MGMT					0x2

#define NCI_GID_PROPRIETARY					0xf



/* ----- NCI over SPI head/crc(tail) room needed for outgoing frames ----- */

#define NCI_SPI_HDR_LEN						4

#define NCI_SPI_CRC_LEN						2



/* ---- NCI Packet structures ---- */

#define NCI_CTRL_HDR_SIZE					3

#define NCI_DATA_HDR_SIZE					3

include/net/nfc/nci_core.h

+11 −30
Original line number Diff line number Diff line
@@ -207,16 +207,14 @@ int nci_to_errno(__u8 code); 
#define NCI_SPI_CRC_ENABLED	0x01



/* ----- NCI SPI structures ----- */

struct nci_spi_dev;

struct nci_spi;



struct nci_spi_ops {

	int (*open)(struct nci_spi_dev *nsdev);

	int (*close)(struct nci_spi_dev *nsdev);

	void (*assert_int)(struct nci_spi_dev *nsdev);

	void (*deassert_int)(struct nci_spi_dev *nsdev);

	void (*assert_int)(struct nci_spi *nspi);

	void (*deassert_int)(struct nci_spi *nspi);

};



struct nci_spi_dev {

struct nci_spi {

	struct nci_dev		*ndev;

	struct spi_device	*spi;

	struct nci_spi_ops	*ops;
@@ -227,31 +225,14 @@ struct nci_spi_dev { 


	struct completion	req_completion;

	u8			req_result;



	void			*driver_data;

};



/* ----- NCI SPI Devices ----- */

struct nci_spi_dev *nci_spi_allocate_device(struct spi_device *spi,

/* ----- NCI SPI ----- */

struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,

				     struct nci_spi_ops *ops,

						u32 supported_protocols,

						u32 supported_se,

						u8 acknowledge_mode,

						unsigned int delay);

void nci_spi_free_device(struct nci_spi_dev *nsdev);

int nci_spi_register_device(struct nci_spi_dev *nsdev);

void nci_spi_unregister_device(struct nci_spi_dev *nsdev);

int nci_spi_recv_frame(struct nci_spi_dev *nsdev);



static inline void nci_spi_set_drvdata(struct nci_spi_dev *nsdev,

					    void *data)

{

	nsdev->driver_data = data;

}



static inline void *nci_spi_get_drvdata(struct nci_spi_dev *nsdev)

{

	return nsdev->driver_data;

}

				     u8 acknowledge_mode, unsigned int delay,

				     struct nci_dev *ndev);

int nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb);

int nci_spi_recv_frame(struct nci_spi *nspi);



#endif /* __NCI_CORE_H */

net/nfc/nci/spi.c

+55 −125
Original line number Diff line number Diff line
@@ -24,8 +24,6 @@ 
#include <linux/nfc.h>

#include <net/nfc/nci_core.h>



#define NCI_SPI_HDR_LEN			4

#define NCI_SPI_CRC_LEN			2

#define NCI_SPI_ACK_SHIFT		6

#define NCI_SPI_MSB_PAYLOAD_MASK	0x3F
@@ -41,21 +39,7 @@ 


#define CRC_INIT		0xFFFF



static int nci_spi_open(struct nci_dev *ndev)

{

	struct nci_spi_dev *nsdev = nci_get_drvdata(ndev);



	return nsdev->ops->open(nsdev);

}



static int nci_spi_close(struct nci_dev *ndev)

{

	struct nci_spi_dev *nsdev = nci_get_drvdata(ndev);



	return nsdev->ops->close(nsdev);

}



static int __nci_spi_send(struct nci_spi_dev *nsdev, struct sk_buff *skb)

static int __nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)

{

	struct spi_message m;

	struct spi_transfer t;
@@ -63,32 +47,31 @@ static int __nci_spi_send(struct nci_spi_dev *nsdev, struct sk_buff *skb) 
	t.tx_buf = skb->data;

	t.len = skb->len;

	t.cs_change = 0;

	t.delay_usecs = nsdev->xfer_udelay;

	t.delay_usecs = nspi->xfer_udelay;



	spi_message_init(&m);

	spi_message_add_tail(&t, &m);



	return spi_sync(nsdev->spi, &m);

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

}



static int nci_spi_send(struct nci_dev *ndev, struct sk_buff *skb)

int nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)

{

	struct nci_spi_dev *nsdev = nci_get_drvdata(ndev);

	unsigned int payload_len = skb->len;

	unsigned char *hdr;

	int ret;

	long completion_rc;



	nsdev->ops->deassert_int(nsdev);

	nspi->ops->deassert_int(nspi);



	/* 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] = nsdev->acknowledge_mode;

	hdr[1] = nspi->acknowledge_mode;

	hdr[2] = payload_len >> 8;

	hdr[3] = payload_len & 0xFF;



	if (nsdev->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

		u16 crc;



		crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
@@ -96,123 +79,70 @@ static int nci_spi_send(struct nci_dev *ndev, struct sk_buff *skb) 
		*skb_put(skb, 1) = crc & 0xFF;

	}



	ret = __nci_spi_send(nsdev, skb);

	ret = __nci_spi_send(nspi, skb);



	kfree_skb(skb);

	nsdev->ops->assert_int(nsdev);

	nspi->ops->assert_int(nspi);



	if (ret != 0 || nsdev->acknowledge_mode == NCI_SPI_CRC_DISABLED)

	if (ret != 0 || nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)

		goto done;



	init_completion(&nsdev->req_completion);

	init_completion(&nspi->req_completion);

	completion_rc =	wait_for_completion_interruptible_timeout(

							&nsdev->req_completion,

							&nspi->req_completion,

							NCI_SPI_SEND_TIMEOUT);



	if (completion_rc <= 0 || nsdev->req_result == ACKNOWLEDGE_NACK)

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

		ret = -EIO;



done:

	return ret;

}



static struct nci_ops nci_spi_ops = {

	.open = nci_spi_open,

	.close = nci_spi_close,

	.send = nci_spi_send,

};

EXPORT_SYMBOL_GPL(nci_spi_send);



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



/**

 * nci_spi_allocate_device - allocate a new nci spi device

 * nci_spi_allocate_spi - allocate a new nci spi

 *

 * @spi: SPI device

 * @ops: device operations

 * @supported_protocols: NFC protocols supported by the device

 * @supported_se: NFC Secure Elements supported by the device

 * @acknowledge_mode: Acknowledge mode used by the 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_dev *nci_spi_allocate_device(struct spi_device *spi,

struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,

				     struct nci_spi_ops *ops,

						u32 supported_protocols,

						u32 supported_se,

						u8 acknowledge_mode,

						unsigned int delay)

				     u8 acknowledge_mode, unsigned int delay,

				     struct nci_dev *ndev)

{

	struct nci_spi_dev *nsdev;

	int tailroom = 0;



	if (!ops->open || !ops->close || !ops->assert_int || !ops->deassert_int)

		return NULL;



	if (!supported_protocols)

		return NULL;

	struct nci_spi *nspi;



	nsdev = devm_kzalloc(&spi->dev, sizeof(struct nci_spi_dev), GFP_KERNEL);

	if (!nsdev)

	if (!ops->assert_int || !ops->deassert_int)

		return NULL;



	nsdev->ops = ops;

	nsdev->acknowledge_mode = acknowledge_mode;

	nsdev->xfer_udelay = delay;



	if (acknowledge_mode == NCI_SPI_CRC_ENABLED)

		tailroom += NCI_SPI_CRC_LEN;



	nsdev->ndev = nci_allocate_device(&nci_spi_ops, supported_protocols,

					  NCI_SPI_HDR_LEN, tailroom);

	if (!nsdev->ndev)

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

	if (!nspi)

		return NULL;



	nci_set_drvdata(nsdev->ndev, nsdev);



	return nsdev;

}

EXPORT_SYMBOL_GPL(nci_spi_allocate_device);



/**

 * nci_spi_free_device - deallocate nci spi device

 *

 * @nsdev: The nci spi device to deallocate

 */

void nci_spi_free_device(struct nci_spi_dev *nsdev)

{

	nci_free_device(nsdev->ndev);

}

EXPORT_SYMBOL_GPL(nci_spi_free_device);

	nspi->ops = ops;

	nspi->acknowledge_mode = acknowledge_mode;

	nspi->xfer_udelay = delay;



/**

 * nci_spi_register_device - register a nci spi device in the nfc subsystem

 *

 * @pdev: The nci spi device to register

 */

int nci_spi_register_device(struct nci_spi_dev *nsdev)

{

	return nci_register_device(nsdev->ndev);

}

EXPORT_SYMBOL_GPL(nci_spi_register_device);

	nspi->ndev = ndev;



/**

 * nci_spi_unregister_device - unregister a nci spi device in the nfc subsystem

 *

 * @dev: The nci spi device to unregister

 */

void nci_spi_unregister_device(struct nci_spi_dev *nsdev)

{

	nci_unregister_device(nsdev->ndev);

	return nspi;

}

EXPORT_SYMBOL_GPL(nci_spi_unregister_device);

EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);



static int send_acknowledge(struct nci_spi_dev *nsdev, u8 acknowledge)

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(nsdev->ndev, 0, GFP_KERNEL);

	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);
@@ -225,14 +155,14 @@ static int send_acknowledge(struct nci_spi_dev *nsdev, u8 acknowledge) 
	*skb_put(skb, 1) = crc >> 8;

	*skb_put(skb, 1) = crc & 0xFF;



	ret = __nci_spi_send(nsdev, skb);

	ret = __nci_spi_send(nspi, skb);



	kfree_skb(skb);



	return ret;

}



static struct sk_buff *__nci_spi_recv_frame(struct nci_spi_dev *nsdev)

static struct sk_buff *__nci_spi_recv_frame(struct nci_spi *nspi)

{

	struct sk_buff *skb;

	struct spi_message m;
@@ -243,7 +173,7 @@ static struct sk_buff *__nci_spi_recv_frame(struct nci_spi_dev *nsdev) 


	spi_message_init(&m);

	req[0] = NCI_SPI_DIRECT_READ;

	req[1] = nsdev->acknowledge_mode;

	req[1] = nspi->acknowledge_mode;

	tx.tx_buf = req;

	tx.len = 2;

	tx.cs_change = 0;
@@ -252,18 +182,18 @@ static struct sk_buff *__nci_spi_recv_frame(struct nci_spi_dev *nsdev) 
	rx.len = 2;

	rx.cs_change = 1;

	spi_message_add_tail(&rx, &m);

	ret = spi_sync(nsdev->spi, &m);

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



	if (ret)

		return NULL;



	if (nsdev->acknowledge_mode == NCI_SPI_CRC_ENABLED)

	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(nsdev->ndev, rx_len, GFP_KERNEL);

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

	if (!skb)

		return NULL;
@@ -271,14 +201,14 @@ static struct sk_buff *__nci_spi_recv_frame(struct nci_spi_dev *nsdev) 
	rx.rx_buf = skb_put(skb, rx_len);

	rx.len = rx_len;

	rx.cs_change = 0;

	rx.delay_usecs = nsdev->xfer_udelay;

	rx.delay_usecs = nspi->xfer_udelay;

	spi_message_add_tail(&rx, &m);

	ret = spi_sync(nsdev->spi, &m);

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



	if (ret)

		goto receive_error;



	if (nsdev->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

		*skb_push(skb, 1) = resp_hdr[1];

		*skb_push(skb, 1) = resp_hdr[0];

	}
@@ -320,7 +250,7 @@ static u8 nci_spi_get_ack(struct sk_buff *skb) 
/**

 * nci_spi_recv_frame - receive frame from NCI SPI drivers

 *

 * @nsdev: The nci spi device

 * @nspi: The nci spi

 * Context: can sleep

 *

 * This call may only be used from a context that may sleep.  The sleep
@@ -328,32 +258,32 @@ static u8 nci_spi_get_ack(struct sk_buff *skb) 
 *

 * It returns zero on success, else a negative error code.

 */

int nci_spi_recv_frame(struct nci_spi_dev *nsdev)

int nci_spi_recv_frame(struct nci_spi *nspi)

{

	struct sk_buff *skb;

	int ret = 0;



	nsdev->ops->deassert_int(nsdev);

	nspi->ops->deassert_int(nspi);



	/* Retrieve frame from SPI */

	skb = __nci_spi_recv_frame(nsdev);

	skb = __nci_spi_recv_frame(nspi);

	if (!skb) {

		ret = -EIO;

		goto done;

	}



	if (nsdev->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {

		if (!nci_spi_check_crc(skb)) {

			send_acknowledge(nsdev, ACKNOWLEDGE_NACK);

			send_acknowledge(nspi, ACKNOWLEDGE_NACK);

			goto done;

		}



		/* In case of acknowledged mode: if ACK or NACK received,

		 * unblock completion of latest frame sent.

		 */

		nsdev->req_result = nci_spi_get_ack(skb);

		if (nsdev->req_result)

			complete(&nsdev->req_completion);

		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),
@@ -364,14 +294,14 @@ int nci_spi_recv_frame(struct nci_spi_dev *nsdev) 
		goto done;

	}



	if (nsdev->acknowledge_mode == NCI_SPI_CRC_ENABLED)

		send_acknowledge(nsdev, ACKNOWLEDGE_ACK);

	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)

		send_acknowledge(nspi, ACKNOWLEDGE_ACK);



	/* Forward skb to NCI core layer */

	ret = nci_recv_frame(nsdev->ndev, skb);

	ret = nci_recv_frame(nspi->ndev, skb);



done:

	nsdev->ops->assert_int(nsdev);

	nspi->ops->assert_int(nspi);



	return ret;

}

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