/*
* 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 st21nfcb_nci_i2c_write(void *phy_id, struct sk_buff *skb)
{
int r = -1;
struct st21nfcb_i2c_phy *phy = phy_id;
struct i2c_client *client = phy->i2c_dev;
I2C_DUMP_SKB("st21nfcb_nci_i2c_write", skb);
if (phy->hard_fault != 0)
return phy->hard_fault;
r = i2c_master_send(client, skb->data, skb->len);
if (r == -EREMOTEIO) { /* Retry, chip was in standby */
usleep_range(1000, 4000);
r = i2c_master_send(client, skb->data, skb->len);
}
if (r >= 0) {
if (r != skb->len)
r = -EREMOTEIO;
else
r = 0;
}
st21nfcb_nci_remove_header(skb);
return r;
}
static int microread_i2c_write(void *phy_id, struct sk_buff *skb)
{
int r;
struct microread_i2c_phy *phy = phy_id;
struct i2c_client *client = phy->i2c_dev;
if (phy->hard_fault != 0)
return phy->hard_fault;
usleep_range(3000, 6000);
microread_i2c_add_len_crc(skb);
I2C_DUMP_SKB("i2c frame written", skb);
r = i2c_master_send(client, skb->data, skb->len);
if (r == -EREMOTEIO) { /* Retry, chip was in standby */
usleep_range(6000, 10000);
r = i2c_master_send(client, skb->data, skb->len);
}
if (r >= 0) {
if (r != skb->len)
r = -EREMOTEIO;
else
r = 0;
}
microread_i2c_remove_len_crc(skb);
return r;
}
static int microread_i2c_read(struct microread_i2c_phy *phy,
struct sk_buff **skb)
{
int r;
u8 len;
u8 tmp[MICROREAD_I2C_LLC_MAX_SIZE - 1];
struct i2c_client *client = phy->i2c_dev;
r = i2c_master_recv(client, &len, 1);
if (r != 1) {
nfc_err(&client->dev, "cannot read len byte\n");
return -EREMOTEIO;
}
if ((len < MICROREAD_I2C_LLC_MIN_SIZE) ||
(len > MICROREAD_I2C_LLC_MAX_SIZE)) {
nfc_err(&client->dev, "invalid len byte\n");
r = -EBADMSG;
goto flush;
}
*skb = alloc_skb(1 + len, GFP_KERNEL);
if (*skb == NULL) {
r = -ENOMEM;
goto flush;
}
*skb_put(*skb, 1) = len;
r = i2c_master_recv(client, skb_put(*skb, len), len);
if (r != len) {
kfree_skb(*skb);
return -EREMOTEIO;
}
I2C_DUMP_SKB("cc frame read", *skb);
r = check_crc(*skb);
if (r != 0) {
kfree_skb(*skb);
r = -EBADMSG;
goto flush;
}
skb_pull(*skb, 1);
skb_trim(*skb, (*skb)->len - MICROREAD_I2C_FRAME_TAILROOM);
usleep_range(3000, 6000);
return 0;
flush:
if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
r = -EREMOTEIO;
usleep_range(3000, 6000);
return r;
}
/*
* Reads an ndlc frame and returns it in a newly allocated sk_buff.
* returns:
* frame size : if received frame is complete (find ST21NFCB_SOF_EOF at
* end of read)
* -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF
* at end of read)
* -EREMOTEIO : i2c read error (fatal)
* -EBADMSG : frame was incorrect and discarded
* (value returned from st21nfcb_nci_i2c_repack)
* -EIO : if no ST21NFCB_SOF_EOF is found after reaching
* the read length end sequence
*/
static int st21nfcb_nci_i2c_read(struct st21nfcb_i2c_phy *phy,
struct sk_buff **skb)
{
int r;
u8 len;
u8 buf[ST21NFCB_NCI_I2C_MAX_SIZE];
struct i2c_client *client = phy->i2c_dev;
r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
if (r == -EREMOTEIO) { /* Retry, chip was in standby */
usleep_range(1000, 4000);
r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
} else if (r != ST21NFCB_NCI_I2C_MIN_SIZE) {
nfc_err(&client->dev, "cannot read ndlc & nci header\n");
return -EREMOTEIO;
}
len = be16_to_cpu(*(__be16 *) (buf + 2));
if (len > ST21NFCB_NCI_I2C_MAX_SIZE) {
nfc_err(&client->dev, "invalid frame len\n");
return -EBADMSG;
}
*skb = alloc_skb(ST21NFCB_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
if (*skb == NULL)
return -ENOMEM;
skb_reserve(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
skb_put(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
memcpy((*skb)->data, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
if (!len)
return 0;
r = i2c_master_recv(client, buf, len);
if (r != len) {
kfree_skb(*skb);
return -EREMOTEIO;
}
skb_put(*skb, len);
memcpy((*skb)->data + ST21NFCB_NCI_I2C_MIN_SIZE, buf, len);
I2C_DUMP_SKB("i2c frame read", *skb);
return 0;
}
