net: ti: am65-cpsw-nuss: Enforce pinctrl state on the MDIO child node

The binding represents the MDIO controller as a child device tree
node of the MAC device tree node.

The U-Boot driver mostly ignores that child device tree node and just
hardcodes the resources it uses to support both the MAC and MDIO in a
single driver.

However, some resources like pinctrl muxing states are thus ignored.
This has been a problem with some device trees that will put some
pinctrl states on the MDIO device tree node, like the SK-AM62 Device
Tree does.

Let's rework the driver a bit to create a dummy MDIO driver that we will
then get during our initialization to force the core to select the right
muxing.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Acked-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Nishanth Menon <nm@ti.com>

diff --git a/drivers/net/ti/Kconfig b/drivers/net/ti/Kconfig
index e13dbc9401825c7a5d6a97611a496dc616e851f0..08c81f79adf91ca3a1d09f35f24e6d3df26eeef9 100644 (file)
--- a/drivers/net/ti/Kconfig
+++ b/drivers/net/ti/Kconfig
@@ -41,6 +41,7 @@ endchoice
 config TI_AM65_CPSW_NUSS
        bool "TI K3 AM65x MCU CPSW Nuss Ethernet controller driver"
        depends on ARCH_K3
+       imply DM_MDIO
        imply MISC_INIT_R
        imply MISC
        select PHYLIB

diff --git a/drivers/net/ti/am65-cpsw-nuss.c b/drivers/net/ti/am65-cpsw-nuss.c
index 523a4c9f919ef4bb67558641a5d0bea87fbc98d1..b0dd1b9bd35952efef98f7bb6feccccb210a2e8c 100644 (file)
--- a/drivers/net/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ti/am65-cpsw-nuss.c
@@ -15,6 +15,7 @@
 #include <dm.h>
 #include <dm/device_compat.h>
 #include <dm/lists.h>
+#include <dm/pinctrl.h>
 #include <dma-uclass.h>
 #include <dm/of_access.h>
 #include <miiphy.h>
@@ -561,14 +562,62 @@ static const struct soc_attr k3_mdio_soc_data[] = {
        { /* sentinel */ },
 };
 
+static ofnode am65_cpsw_find_mdio(ofnode parent)
+{
+       ofnode node;
+
+       ofnode_for_each_subnode(node, parent)
+               if (ofnode_device_is_compatible(node, "ti,cpsw-mdio"))
+                       return node;
+
+       return ofnode_null();
+}
+
+static int am65_cpsw_mdio_setup(struct udevice *dev)
+{
+       struct am65_cpsw_priv *priv = dev_get_priv(dev);
+       struct am65_cpsw_common *cpsw_common = priv->cpsw_common;
+       struct udevice *mdio_dev;
+       ofnode mdio;
+       int ret;
+
+       mdio = am65_cpsw_find_mdio(dev_ofnode(cpsw_common->dev));
+       if (!ofnode_valid(mdio))
+               return 0;
+
+       /*
+        * The MDIO controller is represented in the DT binding by a
+        * subnode of the MAC controller.
+        *
+        * We don't have a DM driver for the MDIO device yet, and thus any
+        * pinctrl setting on its node will be ignored.
+        *
+        * However, we do need to make sure the pins states tied to the
+        * MDIO node are configured properly. Fortunately, the core DM
+        * does that for use when we get a device, so we can work around
+        * that whole issue by just requesting a dummy MDIO driver to
+        * probe, and our pins will get muxed.
+        */
+       ret = uclass_get_device_by_ofnode(UCLASS_MDIO, mdio, &mdio_dev);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
 static int am65_cpsw_mdio_init(struct udevice *dev)
 {
        struct am65_cpsw_priv *priv = dev_get_priv(dev);
        struct am65_cpsw_common *cpsw_common = priv->cpsw_common;
+       int ret;
 
        if (!priv->has_phy || cpsw_common->bus)
                return 0;
 
+       ret = am65_cpsw_mdio_setup(dev);
+       if (ret)
+               return ret;
+
        cpsw_common->bus = cpsw_mdio_init(dev->name,
                                          cpsw_common->mdio_base,
                                          cpsw_common->bus_freq,
@@ -837,3 +886,14 @@ U_BOOT_DRIVER(am65_cpsw_nuss_port) = {
        .plat_auto      = sizeof(struct eth_pdata),
        .flags = DM_FLAG_ALLOC_PRIV_DMA | DM_FLAG_OS_PREPARE,
 };
+
+static const struct udevice_id am65_cpsw_mdio_ids[] = {
+       { .compatible = "ti,cpsw-mdio" },
+       { }
+};
+
+U_BOOT_DRIVER(am65_cpsw_mdio) = {
+       .name           = "am65_cpsw_mdio",
+       .id             = UCLASS_MDIO,
+       .of_match       = am65_cpsw_mdio_ids,
+};