Commit 800fcab8 authored by Andrew Lunn's avatar Andrew Lunn Committed by David S. Miller
Browse files

net: phy: Add support for microchip SMI0 MDIO bus 



SMI0 is a mangled version of MDIO. The main low level difference is
the MDIO C22 OP code is always 0, not 0x2 or 0x1 for Read/Write. The
read/write information is instead encoded in the PHY address.

Extend the bit-bang code to allow the op code to be overridden, but
default to normal C22 values. Add an extra compatible to the mdio-gpio
driver, and when this compatible is present, set the op codes to 0.

A higher level driver, sitting on top of the basic MDIO bus driver can
then implement the rest of the microchip SMI0 odderties.

Signed-off-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 61df0e7b

drivers/net/mdio/mdio-bitbang.c

+6 −2
Original line number Diff line number Diff line
@@ -158,7 +158,7 @@ int mdiobb_read(struct mii_bus *bus, int phy, int reg) 
		reg = mdiobb_cmd_addr(ctrl, phy, reg);

		mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg);

	} else

		mdiobb_cmd(ctrl, MDIO_READ, phy, reg);

		mdiobb_cmd(ctrl, ctrl->op_c22_read, phy, reg);



	ctrl->ops->set_mdio_dir(ctrl, 0);
@@ -190,7 +190,7 @@ int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val) 
		reg = mdiobb_cmd_addr(ctrl, phy, reg);

		mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg);

	} else

		mdiobb_cmd(ctrl, MDIO_WRITE, phy, reg);

		mdiobb_cmd(ctrl, ctrl->op_c22_write, phy, reg);



	/* send the turnaround (10) */

	mdiobb_send_bit(ctrl, 1);
@@ -217,6 +217,10 @@ struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl) 
	bus->read = mdiobb_read;

	bus->write = mdiobb_write;

	bus->priv = ctrl;

	if (!ctrl->override_op_c22) {

		ctrl->op_c22_read = MDIO_READ;

		ctrl->op_c22_write = MDIO_WRITE;

	}



	return bus;

}

drivers/net/mdio/mdio-gpio.c

+8 −0
Original line number Diff line number Diff line
@@ -132,6 +132,13 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev, 
		new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;

	}



	if (dev->of_node &&

	    of_device_is_compatible(dev->of_node, "microchip,mdio-smi0")) {

		bitbang->ctrl.op_c22_read = 0;

		bitbang->ctrl.op_c22_write = 0;

		bitbang->ctrl.override_op_c22 = 1;

	}



	dev_set_drvdata(dev, new_bus);



	return new_bus;
@@ -196,6 +203,7 @@ static int mdio_gpio_remove(struct platform_device *pdev) 


static const struct of_device_id mdio_gpio_of_match[] = {

	{ .compatible = "virtual,mdio-gpio", },

	{ .compatible = "microchip,mdio-smi0" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mdio_gpio_of_match);

include/linux/mdio-bitbang.h

+3 −0
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ struct mdiobb_ops { 


struct mdiobb_ctrl {

	const struct mdiobb_ops *ops;

	unsigned int override_op_c22;

	u8 op_c22_read;

	u8 op_c22_write;

};



int mdiobb_read(struct mii_bus *bus, int phy, int reg);