/*
* Reads an ndlc frame from the chip.
*
* On ST21NFCB, IRQ goes in idle state when read starts.
*/
static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
{
struct st_nci_spi_phy *phy = phy_id;
struct spi_device *dev;
struct sk_buff *skb = NULL;
int r;
if (!phy || !phy->ndlc || irq != phy->spi_dev->irq) {
WARN_ON_ONCE(1);
return IRQ_NONE;
}
dev = phy->spi_dev;
dev_dbg(&dev->dev, "IRQ\n");
if (phy->ndlc->hard_fault)
return IRQ_HANDLED;
if (!phy->ndlc->powered) {
st_nci_spi_disable(phy);
return IRQ_HANDLED;
}
r = st_nci_spi_read(phy, &skb);
if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
return IRQ_HANDLED;
ndlc_recv(phy->ndlc, skb);
return IRQ_HANDLED;
}
/*
* Reads an ndlc frame from the chip.
*
* On ST21NFCB, IRQ goes in idle state when read starts.
*/
static irqreturn_t st21nfcb_nci_irq_thread_fn(int irq, void *phy_id)
{
struct st21nfcb_i2c_phy *phy = phy_id;
struct i2c_client *client;
struct sk_buff *skb = NULL;
int r;
if (!phy || irq != phy->i2c_dev->irq) {
WARN_ON_ONCE(1);
return IRQ_NONE;
}
client = phy->i2c_dev;
dev_dbg(&client->dev, "IRQ\n");
if (phy->hard_fault)
return IRQ_HANDLED;
if (!phy->powered) {
st21nfcb_nci_i2c_disable(phy);
return IRQ_HANDLED;
}
r = st21nfcb_nci_i2c_read(phy, &skb);
if (r == -EREMOTEIO) {
phy->hard_fault = r;
ndlc_recv(phy->ndlc, NULL);
return IRQ_HANDLED;
} else if (r == -ENOMEM || r == -EBADMSG) {
return IRQ_HANDLED;
}
ndlc_recv(phy->ndlc, skb);
return IRQ_HANDLED;
}
/*
* Writing a frame must not return the number of written bytes.
* It must return either zero for success, or <0 for error.
* In addition, it must not alter the skb
*/
static int st_nci_spi_write(void *phy_id, struct sk_buff *skb)
{
int r;
struct st_nci_spi_phy *phy = phy_id;
struct spi_device *dev = phy->spi_dev;
struct sk_buff *skb_rx;
u8 buf[ST_NCI_SPI_MAX_SIZE + NCI_DATA_HDR_SIZE +
ST_NCI_FRAME_HEADROOM + ST_NCI_FRAME_TAILROOM];
struct spi_transfer spi_xfer = {
.tx_buf = skb->data,
.rx_buf = buf,
.len = skb->len,
};
if (phy->ndlc->hard_fault != 0)
return phy->ndlc->hard_fault;
r = spi_sync_transfer(dev, &spi_xfer, 1);
/*
* We may have received some valuable data on miso line.
* Send them back in the ndlc state machine.
*/
if (!r) {
skb_rx = alloc_skb(skb->len, GFP_KERNEL);
if (!skb_rx) {
r = -ENOMEM;
goto exit;
}
skb_put(skb_rx, skb->len);
memcpy(skb_rx->data, buf, skb->len);
ndlc_recv(phy->ndlc, skb_rx);
}
exit:
return r;
}
/*
* Reads an ndlc frame and returns it in a newly allocated sk_buff.
* returns:
* 0 : if received frame is complete
* -EREMOTEIO : i2c read error (fatal)
* -EBADMSG : frame was incorrect and discarded
* -ENOMEM : cannot allocate skb, frame dropped
*/
static int st_nci_spi_read(struct st_nci_spi_phy *phy,
struct sk_buff **skb)
{
int r;
u8 len;
u8 buf[ST_NCI_SPI_MAX_SIZE];
struct spi_device *dev = phy->spi_dev;
struct spi_transfer spi_xfer = {
.rx_buf = buf,
.len = ST_NCI_SPI_MIN_SIZE,
};
r = spi_sync_transfer(dev, &spi_xfer, 1);
if (r < 0)
return -EREMOTEIO;
len = be16_to_cpu(*(__be16 *) (buf + 2));
if (len > ST_NCI_SPI_MAX_SIZE) {
nfc_err(&dev->dev, "invalid frame len\n");
phy->ndlc->hard_fault = 1;
return -EBADMSG;
}
*skb = alloc_skb(ST_NCI_SPI_MIN_SIZE + len, GFP_KERNEL);
if (*skb == NULL)
return -ENOMEM;
skb_reserve(*skb, ST_NCI_SPI_MIN_SIZE);
skb_put(*skb, ST_NCI_SPI_MIN_SIZE);
memcpy((*skb)->data, buf, ST_NCI_SPI_MIN_SIZE);
if (!len)
return 0;
spi_xfer.len = len;
r = spi_sync_transfer(dev, &spi_xfer, 1);
if (r < 0) {
kfree_skb(*skb);
return -EREMOTEIO;
}
skb_put(*skb, len);
memcpy((*skb)->data + ST_NCI_SPI_MIN_SIZE, buf, len);
return 0;
}
