drivers/nfc/nfcmrvl/i2c.c

Source file repositories/reference/linux-study-clean/drivers/nfc/nfcmrvl/i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/nfc/nfcmrvl/i2c.c
Extension
.c
Size
6248 bytes
Lines
275
Domain
Driver Families
Bucket
drivers/nfc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct nfcmrvl_i2c_drv_data {
	unsigned long flags;
	struct device *dev;
	struct i2c_client *i2c;
	struct nfcmrvl_private *priv;
};

static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
			    struct sk_buff **skb)
{
	int ret;
	struct nci_ctrl_hdr nci_hdr;

	/* Read NCI header to know the payload size */
	ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
	if (ret != NCI_CTRL_HDR_SIZE) {
		nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
		return -EBADMSG;
	}

	*skb = nci_skb_alloc(drv_data->priv->ndev,
			     nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
	if (!*skb)
		return -ENOMEM;

	/* Copy NCI header into the SKB */
	skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);

	if (nci_hdr.plen) {
		/* Read the NCI payload */
		ret = i2c_master_recv(drv_data->i2c,
				      skb_put(*skb, nci_hdr.plen),
				      nci_hdr.plen);

		if (ret != nci_hdr.plen) {
			nfc_err(&drv_data->i2c->dev,
				"Invalid frame payload length: %u (expected %u)\n",
				ret, nci_hdr.plen);
			kfree_skb(*skb);
			return -EBADMSG;
		}
	}

	return 0;
}

static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
{
	struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
	struct sk_buff *skb = NULL;
	int ret;

	if (!drv_data->priv)
		return IRQ_HANDLED;

	if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
		return IRQ_HANDLED;

	ret = nfcmrvl_i2c_read(drv_data, &skb);

	switch (ret) {
	case -EREMOTEIO:
		set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
		break;
	case -ENOMEM:
	case -EBADMSG:
		nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
		break;
	default:
		if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
			nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
		break;
	}
	return IRQ_HANDLED;
}

static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
{
	struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;

	if (!drv_data)
		return -ENODEV;

	return 0;
}

static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
{
	return 0;
}

Annotation

Implementation Notes