Commit 5c2d0a6a authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Jakub Kicinski
Browse files

net: phy: dp83867: implement support for io_impedance_ctrl nvmem cell 



We have a board where measurements indicate that the current three
options - leaving IO_IMPEDANCE_CTRL at the (factory calibrated) reset
value or using one of the two boolean properties to set it to the
min/max value - are too coarse.

Implement support for the newly added binding allowing device tree to
specify an nvmem cell containing an appropriate value for this
specific board.

Signed-off-by: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a7936798

drivers/net/phy/dp83867.c

+49 −6
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/bitfield.h>

#include <linux/nvmem-consumer.h>



#include <dt-bindings/net/ti-dp83867.h>
@@ -522,6 +523,51 @@ static int dp83867_verify_rgmii_cfg(struct phy_device *phydev) 
}



#if IS_ENABLED(CONFIG_OF_MDIO)

static int dp83867_of_init_io_impedance(struct phy_device *phydev)

{

	struct dp83867_private *dp83867 = phydev->priv;

	struct device *dev = &phydev->mdio.dev;

	struct device_node *of_node = dev->of_node;

	struct nvmem_cell *cell;

	u8 *buf, val;

	int ret;



	cell = of_nvmem_cell_get(of_node, "io_impedance_ctrl");

	if (IS_ERR(cell)) {

		ret = PTR_ERR(cell);

		if (ret != -ENOENT)

			return phydev_err_probe(phydev, ret,

						"failed to get nvmem cell io_impedance_ctrl\n");



		/* If no nvmem cell, check for the boolean properties. */

		if (of_property_read_bool(of_node, "ti,max-output-impedance"))

			dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX;

		else if (of_property_read_bool(of_node, "ti,min-output-impedance"))

			dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN;

		else

			dp83867->io_impedance = -1; /* leave at default */



		return 0;

	}



	buf = nvmem_cell_read(cell, NULL);

	nvmem_cell_put(cell);



	if (IS_ERR(buf))

		return PTR_ERR(buf);



	val = *buf;

	kfree(buf);



	if ((val & DP83867_IO_MUX_CFG_IO_IMPEDANCE_MASK) != val) {

		phydev_err(phydev, "nvmem cell 'io_impedance_ctrl' contents out of range\n");

		return -ERANGE;

	}

	dp83867->io_impedance = val;



	return 0;

}



static int dp83867_of_init(struct phy_device *phydev)

{

	struct dp83867_private *dp83867 = phydev->priv;
@@ -549,12 +595,9 @@ static int dp83867_of_init(struct phy_device *phydev) 
		}

	}



	if (of_property_read_bool(of_node, "ti,max-output-impedance"))

		dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX;

	else if (of_property_read_bool(of_node, "ti,min-output-impedance"))

		dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN;

	else

		dp83867->io_impedance = -1; /* leave at default */

	ret = dp83867_of_init_io_impedance(phydev);

	if (ret)

		return ret;



	dp83867->rxctrl_strap_quirk = of_property_read_bool(of_node,

							    "ti,dp83867-rxctrl-strap-quirk");