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-rw-r--r--net/nfc/nci/spi.c53
1 files changed, 31 insertions, 22 deletions
diff --git a/net/nfc/nci/spi.c b/net/nfc/nci/spi.c
index 734c6dde7751..f1d426f10cce 100644
--- a/net/nfc/nci/spi.c
+++ b/net/nfc/nci/spi.c
@@ -38,15 +38,23 @@
#define CRC_INIT 0xFFFF
-static int __nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)
+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));
- t.tx_buf = skb->data;
- t.len = skb->len;
- t.cs_change = 0;
+ /* 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);
@@ -55,15 +63,15 @@ static int __nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)
return spi_sync(nspi->spi, &m);
}
-int nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)
+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;
- 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;
@@ -79,11 +87,21 @@ int nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)
*skb_put(skb, 1) = crc & 0xFF;
}
- ret = __nci_spi_send(nspi, skb);
+ if (write_handshake_completion) {
+ /* Trick SPI driver to raise chip select */
+ ret = __nci_spi_send(nspi, NULL, 1);
+ if (ret)
+ goto done;
- kfree_skb(skb);
- nspi->ops->assert_int(nspi);
+ /* 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;
@@ -96,6 +114,8 @@ int nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb)
ret = -EIO;
done:
+ kfree_skb(skb);
+
return ret;
}
EXPORT_SYMBOL_GPL(nci_spi_send);
@@ -106,26 +126,20 @@ EXPORT_SYMBOL_GPL(nci_spi_send);
* nci_spi_allocate_spi - allocate a new nci spi
*
* @spi: SPI device
- * @ops: device operations
* @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,
- struct nci_spi_ops *ops,
u8 acknowledge_mode, unsigned int delay,
struct nci_dev *ndev)
{
struct nci_spi *nspi;
- if (!ops->assert_int || !ops->deassert_int)
- return NULL;
-
nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
if (!nspi)
return NULL;
- nspi->ops = ops;
nspi->acknowledge_mode = acknowledge_mode;
nspi->xfer_udelay = delay;
@@ -156,7 +170,7 @@ static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
*skb_put(skb, 1) = crc >> 8;
*skb_put(skb, 1) = crc & 0xFF;
- ret = __nci_spi_send(nspi, skb);
+ ret = __nci_spi_send(nspi, skb, 0);
kfree_skb(skb);
@@ -189,7 +203,6 @@ static struct sk_buff *__nci_spi_read(struct nci_spi *nspi)
spi_message_add_tail(&rx, &m);
ret = spi_sync(nspi->spi, &m);
-
if (ret)
return NULL;
@@ -213,7 +226,6 @@ static struct sk_buff *__nci_spi_read(struct nci_spi *nspi)
spi_message_add_tail(&rx, &m);
ret = spi_sync(nspi->spi, &m);
-
if (ret)
goto receive_error;
@@ -271,8 +283,6 @@ struct sk_buff *nci_spi_read(struct nci_spi *nspi)
{
struct sk_buff *skb;
- nspi->ops->deassert_int(nspi);
-
/* Retrieve frame from SPI */
skb = __nci_spi_read(nspi);
if (!skb)
@@ -305,7 +315,6 @@ struct sk_buff *nci_spi_read(struct nci_spi *nspi)
send_acknowledge(nspi, ACKNOWLEDGE_ACK);
done:
- nspi->ops->assert_int(nspi);
return skb;
}

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