drivers/net/ethernet/freescale/fec_mpc52xx_phy.c

Source file repositories/reference/linux-study-clean/drivers/net/ethernet/freescale/fec_mpc52xx_phy.c

File Facts

System
Linux kernel
Corpus path
drivers/net/ethernet/freescale/fec_mpc52xx_phy.c
Extension
.c
Size
3804 bytes
Lines
155
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 mpc52xx_fec_mdio_priv {
	struct mpc52xx_fec __iomem *regs;
};

static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
		int reg, u32 value)
{
	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
	struct mpc52xx_fec __iomem *fec = priv->regs;
	int tries = 3;

	value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
	value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;

	out_be32(&fec->ievent, FEC_IEVENT_MII);
	out_be32(&fec->mii_data, value);

	/* wait for it to finish, this takes about 23 us on lite5200b */
	while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
		msleep(1);

	if (!tries)
		return -ETIMEDOUT;

	return value & FEC_MII_DATA_OP_RD ?
		in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
}

static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
}

static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
		u16 data)
{
	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
		data | FEC_MII_WRITE_FRAME);
}

static int mpc52xx_fec_mdio_probe(struct platform_device *of)
{
	struct device *dev = &of->dev;
	struct device_node *np = of->dev.of_node;
	struct mii_bus *bus;
	struct mpc52xx_fec_mdio_priv *priv;
	struct resource res;
	int err;

	bus = mdiobus_alloc();
	if (bus == NULL)
		return -ENOMEM;
	priv = kzalloc_obj(*priv);
	if (priv == NULL) {
		err = -ENOMEM;
		goto out_free;
	}

	bus->name = "mpc52xx MII bus";
	bus->read = mpc52xx_fec_mdio_read;
	bus->write = mpc52xx_fec_mdio_write;

	/* setup registers */
	err = of_address_to_resource(np, 0, &res);
	if (err)
		goto out_free;
	priv->regs = ioremap(res.start, resource_size(&res));
	if (priv->regs == NULL) {
		err = -ENOMEM;
		goto out_free;
	}

	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res.start);
	bus->priv = priv;

	bus->parent = dev;
	dev_set_drvdata(dev, bus);

	/* set MII speed */
	out_be32(&priv->regs->mii_speed, ((mpc5xxx_get_bus_frequency(dev) >> 20) / 5) << 1);

	err = of_mdiobus_register(bus, np);
	if (err)
		goto out_unmap;

	return 0;

 out_unmap:
	iounmap(priv->regs);
 out_free:

Annotation

Implementation Notes