drivers/net/dsa/b53/b53_mdio.c

Source file repositories/reference/linux-study-clean/drivers/net/dsa/b53/b53_mdio.c

File Facts

System
Linux kernel
Corpus path
drivers/net/dsa/b53/b53_mdio.c
Extension
.c
Size
9895 bytes
Lines
404
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

#include <linux/kernel.h>
#include <linux/phy.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/brcmphy.h>
#include <linux/rtnetlink.h>
#include <net/dsa.h>

#include "b53_priv.h"

/* MII registers */
#define REG_MII_PAGE    0x10    /* MII Page register */
#define REG_MII_ADDR    0x11    /* MII Address register */
#define REG_MII_DATA0   0x18    /* MII Data register 0 */
#define REG_MII_DATA1   0x19    /* MII Data register 1 */
#define REG_MII_DATA2   0x1a    /* MII Data register 2 */
#define REG_MII_DATA3   0x1b    /* MII Data register 3 */

#define REG_MII_PAGE_ENABLE     BIT(0)
#define REG_MII_ADDR_WRITE      BIT(0)
#define REG_MII_ADDR_READ       BIT(1)

static int b53_mdio_op(struct b53_device *dev, u8 page, u8 reg, u16 op)
{
	int i;
	u16 v;
	int ret;
	struct mii_bus *bus = dev->priv;

	if (dev->current_page != page) {
		/* set page number */
		v = (page << 8) | REG_MII_PAGE_ENABLE;
		ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
					   REG_MII_PAGE, v);
		if (ret)
			return ret;
		dev->current_page = page;
	}

	/* set register address */
	v = (reg << 8) | op;
	ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR, REG_MII_ADDR, v);
	if (ret)
		return ret;

	/* check if operation completed */
	for (i = 0; i < 5; ++i) {
		v = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
					REG_MII_ADDR);
		if (!(v & (REG_MII_ADDR_WRITE | REG_MII_ADDR_READ)))
			break;
		usleep_range(10, 100);
	}

	if (WARN_ON(i == 5))
		return -EIO;

	return 0;
}

static int b53_mdio_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
{
	struct mii_bus *bus = dev->priv;
	int ret;

	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
	if (ret)
		return ret;

	*val = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
				   REG_MII_DATA0) & 0xff;

	return 0;
}

static int b53_mdio_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
{
	struct mii_bus *bus = dev->priv;
	int ret;

	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
	if (ret)
		return ret;

	*val = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR, REG_MII_DATA0);

	return 0;
}

Annotation

Implementation Notes