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

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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: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Rasmus Villemoes 2022-06-14 10:46:12 +02:00 committed by Jakub Kicinski
parent a793679827
commit 5c2d0a6a07
1 changed files with 49 additions and 6 deletions
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55
drivers/net/phy/dp83867.c
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@ -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");