[PATCH v2 net-next 3/5] net/fsl: xgmac_mdio: Support preamble suppression

From: Tobias Waldekranz
Date: Wed Jan 26 2022 - 11:06:02 EST


Support the standard "suppress-preamble" attribute to disable preamble
generation.

Signed-off-by: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
---
drivers/net/ethernet/freescale/xgmac_mdio.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
index 40442d64a247..18bf2370d45a 100644
--- a/drivers/net/ethernet/freescale/xgmac_mdio.c
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -39,6 +39,7 @@ struct tgec_mdio_controller {
#define MDIO_STAT_CLKDIV(x) (((x>>1) & 0xff) << 8)
#define MDIO_STAT_BSY BIT(0)
#define MDIO_STAT_RD_ER BIT(1)
+#define MDIO_STAT_PRE_DIS BIT(5)
#define MDIO_CTL_DEV_ADDR(x) (x & 0x1f)
#define MDIO_CTL_PORT_ADDR(x) ((x & 0x1f) << 5)
#define MDIO_CTL_PRE_DIS BIT(10)
@@ -254,6 +255,21 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
return ret;
}

+static void xgmac_mdio_set_suppress_preamble(struct mii_bus *bus)
+{
+ struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
+ struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
+ struct device *dev = bus->parent;
+ u32 mdio_stat;
+
+ if (!device_property_read_bool(dev, "suppress-preamble"))
+ return;
+
+ mdio_stat = xgmac_read32(&regs->mdio_stat, priv->is_little_endian);
+ mdio_stat |= MDIO_STAT_PRE_DIS;
+ xgmac_write32(mdio_stat, &regs->mdio_stat, priv->is_little_endian);
+}
+
static int xgmac_mdio_probe(struct platform_device *pdev)
{
struct fwnode_handle *fwnode;
@@ -301,6 +317,8 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
priv->has_a011043 = device_property_read_bool(&pdev->dev,
"fsl,erratum-a011043");

+ xgmac_mdio_set_suppress_preamble(bus);
+
fwnode = pdev->dev.fwnode;
if (is_of_node(fwnode))
ret = of_mdiobus_register(bus, to_of_node(fwnode));
--
2.25.1