drivers/net/mdio/mdio-pic64hpsc.c

Source file repositories/reference/linux-study-clean/drivers/net/mdio/mdio-pic64hpsc.c

File Facts

System
Linux kernel
Corpus path
drivers/net/mdio/mdio-pic64hpsc.c
Extension
.c
Size
5196 bytes
Lines
191
Domain
Driver Families
Bucket
drivers/net
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 pic64hpsc_mdio_dev {
	void __iomem *regs;
};

static int pic64hpsc_mdio_wait_trigger(struct mii_bus *bus)
{
	struct pic64hpsc_mdio_dev *priv = bus->priv;
	u32 val;
	int ret;

	/* The MDIO_TRIGGER bit returns 0 when a transaction has completed. */
	ret = readl_poll_timeout(priv->regs + MDIO_REG_FRAME_CFG_2, val,
				 !(val & MDIO_TRIGGER_BIT), 50, 10000);

	if (ret < 0)
		dev_dbg(&bus->dev, "TRIGGER bit timeout: %x\n", val);

	return ret;
}

static int pic64hpsc_mdio_c22_read(struct mii_bus *bus, int mii_id, int regnum)
{
	struct pic64hpsc_mdio_dev *priv = bus->priv;
	u32 val;
	int ret;

	ret = pic64hpsc_mdio_wait_trigger(bus);
	if (ret)
		return ret;

	writel(MDIO_TRIGGER_BIT | FIELD_PREP(MDIO_REG_DEV_ADDR_MASK, regnum) |
		       FIELD_PREP(MDIO_PHY_PRT_ADDR_MASK, mii_id) |
		       FIELD_PREP(MDIO_OPERATION_MASK, MDIO_OPERATION_READ) |
		       FIELD_PREP(MDIO_START_OF_FRAME_MASK, 1),
	       priv->regs + MDIO_REG_FRAME_CFG_2);

	ret = pic64hpsc_mdio_wait_trigger(bus);
	if (ret)
		return ret;

	val = readl(priv->regs + MDIO_REG_FRAME_STATUS);

	/* The MDIO_READOK is a 1-bit value reflecting the inverse of the MDIO
	 * bus value captured during the 2nd TA cycle. A PHY/Port should drive
	 * the MDIO bus with a logic 0 on the 2nd TA cycle, however, the
	 * PHY/Port could optionally drive a logic 1, to communicate a read
	 * failure. This feature is optional, not defined by the 802.3 standard
	 * and not supported in standard external PHYs.
	 */
	if (!(bus->phy_ignore_ta_mask & 1 << mii_id) &&
	    !FIELD_GET(MDIO_READOK_BIT, val)) {
		dev_dbg(&bus->dev, "READOK bit cleared\n");
		return -EIO;
	}

	return FIELD_GET(MDIO_RDATA_MASK, val);
}

static int pic64hpsc_mdio_c22_write(struct mii_bus *bus, int mii_id, int regnum,
				    u16 value)
{
	struct pic64hpsc_mdio_dev *priv = bus->priv;
	int ret;

	ret = pic64hpsc_mdio_wait_trigger(bus);
	if (ret < 0)
		return ret;

	writel(FIELD_PREP(MDIO_WDATA_MASK, value),
	       priv->regs + MDIO_REG_FRAME_CFG_1);

	writel(MDIO_TRIGGER_BIT | FIELD_PREP(MDIO_REG_DEV_ADDR_MASK, regnum) |
		       FIELD_PREP(MDIO_PHY_PRT_ADDR_MASK, mii_id) |
		       FIELD_PREP(MDIO_OPERATION_MASK, MDIO_OPERATION_WRITE) |
		       FIELD_PREP(MDIO_START_OF_FRAME_MASK, 1),
	       priv->regs + MDIO_REG_FRAME_CFG_2);

	return 0;
}

static int pic64hpsc_mdio_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct device *dev = &pdev->dev;
	struct pic64hpsc_mdio_dev *priv;
	struct mii_bus *bus;
	unsigned long rate;
	struct clk *clk;
	u32 bus_freq;
	u32 div;

Annotation

Implementation Notes