Re: [PATCH net-next v3 1/9] net: phy: micrel: move phy reg offsets to common header

quoted

 	switch (reg) {
-	case PHY_REG_CTRL:
+	case MII_BMCR:
 		ksz_pread8(dev, p, regs[P_NEG_RESTART_CTRL], &restart);
 		ksz_pread8(dev, p, regs[P_SPEED_STATUS], &speed);
 		ksz_pread8(dev, p, regs[P_FORCE_CTRL], &ctrl);
 		if (restart & PORT_PHY_LOOPBACK)
-			data |= PHY_LOOPBACK;
+			data |= BMCR_LOOPBACK;
 		if (ctrl & PORT_FORCE_100_MBIT)
-			data |= PHY_SPEED_100MBIT;
+			data |= BMCR_SPEED100;
 		if (ksz_is_ksz88x3(dev)) {
 			if ((ctrl & PORT_AUTO_NEG_ENABLE))
-				data |= PHY_AUTO_NEG_ENABLE;
+				data |= BMCR_ANENABLE;
 		} else {
 			if (!(ctrl & PORT_AUTO_NEG_DISABLE))
-				data |= PHY_AUTO_NEG_ENABLE;
+				data |= BMCR_ANENABLE;
 		}
 		if (restart & PORT_POWER_DOWN)
-			data |= PHY_POWER_DOWN;
+			data |= BMCR_PDOWN;
 		if (restart & PORT_AUTO_NEG_RESTART)
-			data |= PHY_AUTO_NEG_RESTART;
+			data |= BMCR_ANRESTART;
 		if (ctrl & PORT_FORCE_FULL_DUPLEX)
-			data |= PHY_FULL_DUPLEX;
+			data |= BMCR_FULLDPLX;
 		if (speed & PORT_HP_MDIX)
-			data |= PHY_HP_MDIX;
+			data |= KSZ886X_BMCR_HP_MDIX;
 		if (restart & PORT_FORCE_MDIX)
-			data |= PHY_FORCE_MDIX;
+			data |= KSZ886X_BMCR_FORCE_MDI;
 		if (restart & PORT_AUTO_MDIX_DISABLE)
-			data |= PHY_AUTO_MDIX_DISABLE;
+			data |= KSZ886X_BMCR_DISABLE_AUTO_MDIX;
 		if (restart & PORT_TX_DISABLE)
-			data |= PHY_TRANSMIT_DISABLE;
+			data |= KSZ886X_BMCR_DISABLE_TRANSMIT;
 		if (restart & PORT_LED_OFF)
-			data |= PHY_LED_DISABLE;
+			data |= KSZ886X_BMCR_DISABLE_LED;
 		break;

I am deeply confused as to what this function is doing. It is reading
the 8-bit port registers P_NEG_RESTART_CTRL, P_SPEED_STATUS and
P_FORCE_CTRL and stitching them into a 16-bit "MII_BMCR"?

Sort of. Take a look at the datasheet for the ksz8841. It has clause
22 like registers which it exports to a PHY driver. It puts MDIX
control into the bottom of the BMCR. So this DSA driver is emulating
the ksz8841 so it can share the PHY driver.

    Andrew