From 5c2d0a6a0701ba86a4bb0bf1876266c751e328bd Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Tue, 14 Jun 2022 10:46:12 +0200 Subject: 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: Rasmus Villemoes Signed-off-by: Jakub Kicinski --- drivers/net/phy/dp83867.c | 55 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 49 insertions(+), 6 deletions(-) (limited to 'drivers/net/phy/dp83867.c') diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index 13dafe7a29bd..1e38039c5c56 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -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"); -- cgit