[PATCH v9 6/8] net: fec: add support for DM_MDIO

Tim Harvey
2022-11-30T17:44:26Z

Add support for DM_MDIO by registering a UCLASS_MDIO driver and
attempting to use it. This is necessary if wanting to use a DSA
driver for example hanging off of the FEC MAC.

Care is taken to fallback to non DM_MDIO mii bus as several boards define
DM_MDIO without having the proper device-tree configuration necessary
such as an mdio subnode, a phy-mode prop, and either a valid phy-handle
prop or fixed-phy subnode which will cause dm_eth_phy_connect() to fail.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
---
v9:
- no changes
v8:
- no changes
v7:
- no changes
v6:
- no changes
v5:
- added Fabio's rb tag
v4:
- no changes
v3:
- no changes
v2:
- fix fallback mechanism for legacy dt's that do not have phy-handle
and mdio subnode
---
drivers/net/fec_mxc.c | 90 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 88 insertions(+), 2 deletions(-)

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index bbc4434ddb9e..7057472710fa 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -30,6 +30,8 @@
#include <asm/arch/imx-regs.h>
#include <asm/mach-imx/sys_proto.h>
#include <asm-generic/gpio.h>
+#include <dm/device_compat.h>
+#include <dm/lists.h>

#include "fec_mxc.h"
#include <eth_phy.h>
@@ -1026,6 +1028,81 @@ struct mii_dev *fec_get_miibus(ulong base_addr, int dev_id)
return bus;
}

+#ifdef CONFIG_DM_MDIO
+struct dm_fec_mdio_priv {
+ struct ethernet_regs *regs;
+};
+
+static int dm_fec_mdio_read(struct udevice *dev, int addr, int devad, int reg)
+{
+ struct dm_fec_mdio_priv *priv = dev_get_priv(dev);
+
+ return fec_mdio_read(priv->regs, addr, reg);
+}
+
+static int dm_fec_mdio_write(struct udevice *dev, int addr, int devad, int reg, u16 data)
+{
+ struct dm_fec_mdio_priv *priv = dev_get_priv(dev);
+
+ return fec_mdio_write(priv->regs, addr, reg, data);
+}
+
+static const struct mdio_ops dm_fec_mdio_ops = {
+ .read = dm_fec_mdio_read,
+ .write = dm_fec_mdio_write,
+};
+
+static int dm_fec_mdio_probe(struct udevice *dev)
+{
+ struct dm_fec_mdio_priv *priv = dev_get_priv(dev);
+
+ priv->regs = (struct ethernet_regs *)ofnode_get_addr(dev_ofnode(dev->parent));
+
+ return 0;
+}
+
+U_BOOT_DRIVER(fec_mdio) = {
+ .name = "fec_mdio",
+ .id = UCLASS_MDIO,
+ .probe = dm_fec_mdio_probe,
+ .ops = &dm_fec_mdio_ops,
+ .priv_auto = sizeof(struct dm_fec_mdio_priv),
+};
+
+static int dm_fec_bind_mdio(struct udevice *dev)
+{
+ struct udevice *mdiodev;
+ const char *name;
+ ofnode mdio;
+ int ret = -ENODEV;
+
+ /* for a UCLASS_MDIO driver we need to bind and probe manually
+ * for an internal MDIO bus that has no dt compatible of its own
+ */
+ ofnode_for_each_subnode(mdio, dev_ofnode(dev)) {
+ name = ofnode_get_name(mdio);
+
+ if (strcmp(name, "mdio"))
+ continue;
+
+ ret = device_bind_driver_to_node(dev, "fec_mdio",
+ name, mdio, &mdiodev);
+ if (ret) {
+ printf("%s bind %s failed: %d\n", __func__, name, ret);
+ break;
+ }
+
+ /* need to probe it as there is no compatible to do so */
+ ret = uclass_get_device_by_ofnode(UCLASS_MDIO, mdio, &mdiodev);
+ if (!ret)
+ return 0;
+ printf("%s probe %s failed: %d\n", __func__, name, ret);
+ }
+
+ return ret;
+}
+#endif
+
static int fecmxc_read_rom_hwaddr(struct udevice *dev)
{
struct fec_priv *priv = dev_get_priv(dev);
@@ -1089,7 +1166,7 @@ static int device_get_phy_addr(struct fec_priv *priv, struct udevice *dev)

static int fec_phy_init(struct fec_priv *priv, struct udevice *dev)
{
- struct phy_device *phydev;
+ struct phy_device *phydev = NULL;
int addr;

addr = device_get_phy_addr(priv, dev);
@@ -1097,7 +1174,10 @@ static int fec_phy_init(struct fec_priv *priv, struct udevice *dev)
addr = CONFIG_FEC_MXC_PHYADDR;
#endif

- phydev = phy_connect(priv->bus, addr, dev, priv->interface);
+ if (IS_ENABLED(CONFIG_DM_MDIO))
+ phydev = dm_eth_phy_connect(dev);
+ if (!phydev)
+ phydev = phy_connect(priv->bus, addr, dev, priv->interface);
if (!phydev)
return -ENODEV;

@@ -1228,6 +1308,12 @@ static int fecmxc_probe(struct udevice *dev)

priv->dev_id = dev_seq(dev);

+ if (IS_ENABLED(CONFIG_DM_MDIO)) {
+ ret = dm_fec_bind_mdio(dev);
+ if (ret && ret != -ENODEV)
+ return ret;
+ }
+
#ifdef CONFIG_DM_ETH_PHY
bus = eth_phy_get_mdio_bus(dev);
#endif
--
2.25.1