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

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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: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Eric Lapuyade 2013-09-05 11:02:21 +02:00 committed by Samuel Ortiz
parent 08f13acff9
commit fa544fff62
3 changed files with 70 additions and 155 deletions
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4
include/net/nfc/nci.h
View File

@ -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

41
include/net/nfc/nci_core.h
View File

@ -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,
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;
}
/* ----- NCI SPI ----- */
struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,
struct nci_spi_ops *ops,
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 */

180
net/nfc/nci/spi.c
View File

@ -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_ops *ops,
u32 supported_protocols,
u32 supported_se,
u8 acknowledge_mode,
unsigned int delay)
struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,
struct nci_spi_ops *ops,
u8 acknowledge_mode, unsigned int delay,
struct nci_dev *ndev)
{
struct nci_spi_dev *nsdev;
int tailroom = 0;
struct nci_spi *nspi;
if (!ops->open || !ops->close || !ops->assert_int || !ops->deassert_int)
if (!ops->assert_int || !ops->deassert_int)
return NULL;
if (!supported_protocols)
nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
if (!nspi)
return NULL;
nsdev = devm_kzalloc(&spi->dev, sizeof(struct nci_spi_dev), GFP_KERNEL);
if (!nsdev)
return NULL;
nspi->ops = ops;
nspi->acknowledge_mode = acknowledge_mode;
nspi->xfer_udelay = delay;
nsdev->ops = ops;
nsdev->acknowledge_mode = acknowledge_mode;
nsdev->xfer_udelay = delay;
nspi->ndev = ndev;
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)
return NULL;
nci_set_drvdata(nsdev->ndev, nsdev);
return nsdev;
return nspi;
}
EXPORT_SYMBOL_GPL(nci_spi_allocate_device);
EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);
/**
* 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);
/**
* 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);
/**
* 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);
}
EXPORT_SYMBOL_GPL(nci_spi_unregister_device);
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;
}