* [PATCH net-next v8 1/2] net: mdio: Add RTL9300 MDIO driver
2025-02-27 21:32 [PATCH net-next v8 0/2] RTL9300 MDIO driver Chris Packham
@ 2025-02-27 21:32 ` Chris Packham
2025-02-27 21:32 ` [PATCH net-next v8 2/2] mips: dts: realtek: Add MDIO controller Chris Packham
2025-03-04 1:32 ` [PATCH net-next v8 0/2] RTL9300 MDIO driver Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Chris Packham @ 2025-02-27 21:32 UTC (permalink / raw)
To: robh, krzk+dt, conor+dt, tsbogend, andrew, hkallweit1, linux,
davem, edumazet, kuba, pabeni, sander, markus.stockhausen
Cc: devicetree, linux-mips, linux-kernel, netdev, Chris Packham
Add a driver for the MDIO controller on the RTL9300 family of Ethernet
switches with integrated SoC. There are 4 physical SMI interfaces on the
RTL9300 however access is done using the switch ports. The driver takes
the MDIO bus hierarchy from the DTS and uses this to configure the
switch ports so they are associated with the correct PHY. This mapping
is also used when dealing with software requests from phylib.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
Notes:
Changes in v8:
- Fix typo in user visible string
Changes in v7:
- Update out of date comment
- Use for_each_set_bit() instead of open-coded iteration
- Use FIELD_PREP() in a few more places
- Add #defines for register field masks
Changes in v6:
- Parse port->phy mapping from devicetree removing the need for the
realtek,port property
- Remove erroneous code dealing with SMI_POLL_CTRL. When actually
implemented this stops the LED unit from updating correctly.
Changes in v5:
- Reword out of date comment
- Use GENMASK/FIELD_PREP where appropriate
- Introduce port validity bitmap.
- Use more obvious names for PHY_CTRL_READ/WRITE and
PHY_CTRL_TYPE_C45/C22
Changes in v4:
- rename to realtek-rtl9300
- s/realtek_/rtl9300_/
- add locking to support concurrent access
- The dtbinding now represents the MDIO bus hierarchy so we consume this
information and use it to configure the switch port to MDIO bus+addr.
Changes in v3:
- Fix (another) off-by-one error
Changes in v2:
- Add clause 22 support
- Remove commented out code
- Formatting cleanup
- Set MAX_PORTS correctly for MDIO interface
- Fix off-by-one error in pn check
drivers/net/mdio/Kconfig | 7 +
drivers/net/mdio/Makefile | 1 +
drivers/net/mdio/mdio-realtek-rtl9300.c | 475 ++++++++++++++++++++++++
3 files changed, 483 insertions(+)
create mode 100644 drivers/net/mdio/mdio-realtek-rtl9300.c
diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
index 4a7a303be2f7..058fcdaf6c18 100644
--- a/drivers/net/mdio/Kconfig
+++ b/drivers/net/mdio/Kconfig
@@ -185,6 +185,13 @@ config MDIO_IPQ8064
This driver supports the MDIO interface found in the network
interface units of the IPQ8064 SoC
+config MDIO_REALTEK_RTL9300
+ tristate "Realtek RTL9300 MDIO interface support"
+ depends on MACH_REALTEK_RTL || COMPILE_TEST
+ help
+ This driver supports the MDIO interface found in the Realtek
+ RTL9300 family of Ethernet switches with integrated SoC.
+
config MDIO_REGMAP
tristate
help
diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
index 1015f0db4531..c23778e73890 100644
--- a/drivers/net/mdio/Makefile
+++ b/drivers/net/mdio/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o
obj-$(CONFIG_MDIO_MSCC_MIIM) += mdio-mscc-miim.o
obj-$(CONFIG_MDIO_MVUSB) += mdio-mvusb.o
obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o
+obj-$(CONFIG_MDIO_REALTEK_RTL9300) += mdio-realtek-rtl9300.o
obj-$(CONFIG_MDIO_REGMAP) += mdio-regmap.o
obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o
obj-$(CONFIG_MDIO_THUNDER) += mdio-thunder.o
diff --git a/drivers/net/mdio/mdio-realtek-rtl9300.c b/drivers/net/mdio/mdio-realtek-rtl9300.c
new file mode 100644
index 000000000000..0a97c2a9c46d
--- /dev/null
+++ b/drivers/net/mdio/mdio-realtek-rtl9300.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MDIO controller for RTL9300 switches with integrated SoC.
+ *
+ * The MDIO communication is abstracted by the switch. At the software level
+ * communication uses the switch port to address the PHY. We work out the
+ * mapping based on the MDIO bus described in device tree and phandles on the
+ * ethernet-ports property.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/find.h>
+#include <linux/mdio.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define SMI_GLB_CTRL 0xca00
+#define GLB_CTRL_INTF_SEL(intf) BIT(16 + (intf))
+#define SMI_PORT0_15_POLLING_SEL 0xca08
+#define SMI_ACCESS_PHY_CTRL_0 0xcb70
+#define SMI_ACCESS_PHY_CTRL_1 0xcb74
+#define PHY_CTRL_REG_ADDR GENMASK(24, 20)
+#define PHY_CTRL_PARK_PAGE GENMASK(19, 15)
+#define PHY_CTRL_MAIN_PAGE GENMASK(14, 3)
+#define PHY_CTRL_WRITE BIT(2)
+#define PHY_CTRL_READ 0
+#define PHY_CTRL_TYPE_C45 BIT(1)
+#define PHY_CTRL_TYPE_C22 0
+#define PHY_CTRL_CMD BIT(0)
+#define PHY_CTRL_FAIL BIT(25)
+#define SMI_ACCESS_PHY_CTRL_2 0xcb78
+#define PHY_CTRL_INDATA GENMASK(31, 16)
+#define PHY_CTRL_DATA GENMASK(15, 0)
+#define SMI_ACCESS_PHY_CTRL_3 0xcb7c
+#define PHY_CTRL_MMD_DEVAD GENMASK(20, 16)
+#define PHY_CTRL_MMD_REG GENMASK(15, 0)
+#define SMI_PORT0_5_ADDR_CTRL 0xcb80
+
+#define MAX_PORTS 28
+#define MAX_SMI_BUSSES 4
+#define MAX_SMI_ADDR 0x1f
+
+struct rtl9300_mdio_priv {
+ struct regmap *regmap;
+ struct mutex lock; /* protect HW access */
+ DECLARE_BITMAP(valid_ports, MAX_PORTS);
+ u8 smi_bus[MAX_PORTS];
+ u8 smi_addr[MAX_PORTS];
+ bool smi_bus_is_c45[MAX_SMI_BUSSES];
+ struct mii_bus *bus[MAX_SMI_BUSSES];
+};
+
+struct rtl9300_mdio_chan {
+ struct rtl9300_mdio_priv *priv;
+ u8 mdio_bus;
+};
+
+static int rtl9300_mdio_phy_to_port(struct mii_bus *bus, int phy_id)
+{
+ struct rtl9300_mdio_chan *chan = bus->priv;
+ struct rtl9300_mdio_priv *priv = chan->priv;
+ int i;
+
+ for_each_set_bit(i, priv->valid_ports, MAX_PORTS)
+ if (priv->smi_bus[i] == chan->mdio_bus &&
+ priv->smi_addr[i] == phy_id)
+ return i;
+
+ return -ENOENT;
+}
+
+static int rtl9300_mdio_wait_ready(struct rtl9300_mdio_priv *priv)
+{
+ struct regmap *regmap = priv->regmap;
+ u32 val;
+
+ lockdep_assert_held(&priv->lock);
+
+ return regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1,
+ val, !(val & PHY_CTRL_CMD), 10, 1000);
+}
+
+static int rtl9300_mdio_read_c22(struct mii_bus *bus, int phy_id, int regnum)
+{
+ struct rtl9300_mdio_chan *chan = bus->priv;
+ struct rtl9300_mdio_priv *priv = chan->priv;
+ struct regmap *regmap = priv->regmap;
+ int port;
+ u32 val;
+ int err;
+
+ guard(mutex)(&priv->lock);
+
+ port = rtl9300_mdio_phy_to_port(bus, phy_id);
+ if (port < 0)
+ return port;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, FIELD_PREP(PHY_CTRL_INDATA, port));
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_REG_ADDR, regnum) |
+ FIELD_PREP(PHY_CTRL_PARK_PAGE, 0x1f) |
+ FIELD_PREP(PHY_CTRL_MAIN_PAGE, 0xfff) |
+ PHY_CTRL_READ | PHY_CTRL_TYPE_C22 | PHY_CTRL_CMD;
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, val);
+ if (err)
+ return err;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ err = regmap_read(regmap, SMI_ACCESS_PHY_CTRL_2, &val);
+ if (err)
+ return err;
+
+ return FIELD_GET(PHY_CTRL_DATA, val);
+}
+
+static int rtl9300_mdio_write_c22(struct mii_bus *bus, int phy_id, int regnum, u16 value)
+{
+ struct rtl9300_mdio_chan *chan = bus->priv;
+ struct rtl9300_mdio_priv *priv = chan->priv;
+ struct regmap *regmap = priv->regmap;
+ int port;
+ u32 val;
+ int err;
+
+ guard(mutex)(&priv->lock);
+
+ port = rtl9300_mdio_phy_to_port(bus, phy_id);
+ if (port < 0)
+ return port;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_0, BIT(port));
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, FIELD_PREP(PHY_CTRL_INDATA, value));
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_REG_ADDR, regnum) |
+ FIELD_PREP(PHY_CTRL_PARK_PAGE, 0x1f) |
+ FIELD_PREP(PHY_CTRL_MAIN_PAGE, 0xfff) |
+ PHY_CTRL_WRITE | PHY_CTRL_TYPE_C22 | PHY_CTRL_CMD;
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, val);
+ if (err)
+ return err;
+
+ err = regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1,
+ val, !(val & PHY_CTRL_CMD), 10, 100);
+ if (err)
+ return err;
+
+ if (val & PHY_CTRL_FAIL)
+ return -ENXIO;
+
+ return 0;
+}
+
+static int rtl9300_mdio_read_c45(struct mii_bus *bus, int phy_id, int dev_addr, int regnum)
+{
+ struct rtl9300_mdio_chan *chan = bus->priv;
+ struct rtl9300_mdio_priv *priv = chan->priv;
+ struct regmap *regmap = priv->regmap;
+ int port;
+ u32 val;
+ int err;
+
+ guard(mutex)(&priv->lock);
+
+ port = rtl9300_mdio_phy_to_port(bus, phy_id);
+ if (port < 0)
+ return port;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_INDATA, port);
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, val);
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) |
+ FIELD_PREP(PHY_CTRL_MMD_REG, regnum);
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_3, val);
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1,
+ PHY_CTRL_READ | PHY_CTRL_TYPE_C45 | PHY_CTRL_CMD);
+ if (err)
+ return err;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ err = regmap_read(regmap, SMI_ACCESS_PHY_CTRL_2, &val);
+ if (err)
+ return err;
+
+ return FIELD_GET(PHY_CTRL_DATA, val);
+}
+
+static int rtl9300_mdio_write_c45(struct mii_bus *bus, int phy_id, int dev_addr,
+ int regnum, u16 value)
+{
+ struct rtl9300_mdio_chan *chan = bus->priv;
+ struct rtl9300_mdio_priv *priv = chan->priv;
+ struct regmap *regmap = priv->regmap;
+ int port;
+ u32 val;
+ int err;
+
+ guard(mutex)(&priv->lock);
+
+ port = rtl9300_mdio_phy_to_port(bus, phy_id);
+ if (port < 0)
+ return port;
+
+ err = rtl9300_mdio_wait_ready(priv);
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_0, BIT(port));
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_INDATA, value);
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, val);
+ if (err)
+ return err;
+
+ val = FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) |
+ FIELD_PREP(PHY_CTRL_MMD_REG, regnum);
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_3, val);
+ if (err)
+ return err;
+
+ err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1,
+ PHY_CTRL_TYPE_C45 | PHY_CTRL_WRITE | PHY_CTRL_CMD);
+ if (err)
+ return err;
+
+ err = regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1,
+ val, !(val & PHY_CTRL_CMD), 10, 100);
+ if (err)
+ return err;
+
+ if (val & PHY_CTRL_FAIL)
+ return -ENXIO;
+
+ return 0;
+}
+
+static int rtl9300_mdiobus_init(struct rtl9300_mdio_priv *priv)
+{
+ u32 glb_ctrl_mask = 0, glb_ctrl_val = 0;
+ struct regmap *regmap = priv->regmap;
+ u32 port_addr[5] = { 0 };
+ u32 poll_sel[2] = { 0 };
+ int i, err;
+
+ /* Associate the port with the SMI interface and PHY */
+ for_each_set_bit(i, priv->valid_ports, MAX_PORTS) {
+ int pos;
+
+ pos = (i % 6) * 5;
+ port_addr[i / 6] |= (priv->smi_addr[i] & 0x1f) << pos;
+
+ pos = (i % 16) * 2;
+ poll_sel[i / 16] |= (priv->smi_bus[i] & 0x3) << pos;
+ }
+
+ /* Put the interfaces into C45 mode if required */
+ glb_ctrl_mask = GENMASK(19, 16);
+ for (i = 0; i < MAX_SMI_BUSSES; i++)
+ if (priv->smi_bus_is_c45[i])
+ glb_ctrl_val |= GLB_CTRL_INTF_SEL(i);
+
+ err = regmap_bulk_write(regmap, SMI_PORT0_5_ADDR_CTRL,
+ port_addr, 5);
+ if (err)
+ return err;
+
+ err = regmap_bulk_write(regmap, SMI_PORT0_15_POLLING_SEL,
+ poll_sel, 2);
+ if (err)
+ return err;
+
+ err = regmap_update_bits(regmap, SMI_GLB_CTRL,
+ glb_ctrl_mask, glb_ctrl_val);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static int rtl9300_mdiobus_probe_one(struct device *dev, struct rtl9300_mdio_priv *priv,
+ struct fwnode_handle *node)
+{
+ struct rtl9300_mdio_chan *chan;
+ struct fwnode_handle *child;
+ struct mii_bus *bus;
+ u32 mdio_bus;
+ int err;
+
+ err = fwnode_property_read_u32(node, "reg", &mdio_bus);
+ if (err)
+ return err;
+
+ fwnode_for_each_child_node(node, child)
+ if (fwnode_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
+ priv->smi_bus_is_c45[mdio_bus] = true;
+
+ bus = devm_mdiobus_alloc_size(dev, sizeof(*chan));
+ if (!bus)
+ return -ENOMEM;
+
+ bus->name = "Realtek Switch MDIO Bus";
+ bus->read = rtl9300_mdio_read_c22;
+ bus->write = rtl9300_mdio_write_c22;
+ bus->read_c45 = rtl9300_mdio_read_c45;
+ bus->write_c45 = rtl9300_mdio_write_c45;
+ bus->parent = dev;
+ chan = bus->priv;
+ chan->mdio_bus = mdio_bus;
+ chan->priv = priv;
+
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", dev_name(dev), mdio_bus);
+
+ err = devm_of_mdiobus_register(dev, bus, to_of_node(node));
+ if (err)
+ return dev_err_probe(dev, err, "cannot register MDIO bus\n");
+
+ return 0;
+}
+
+/* The mdio-controller is part of a switch block so we parse the sibling
+ * ethernet-ports node and build a mapping of the switch port to MDIO bus/addr
+ * based on the phy-handle.
+ */
+static int rtl9300_mdiobus_map_ports(struct device *dev)
+{
+ struct rtl9300_mdio_priv *priv = dev_get_drvdata(dev);
+ struct device *parent = dev->parent;
+ struct fwnode_handle *port;
+ int err;
+
+ struct fwnode_handle *ports __free(fwnode_handle) =
+ device_get_named_child_node(parent, "ethernet-ports");
+ if (!ports)
+ return dev_err_probe(dev, -EINVAL, "%pfwP missing ethernet-ports\n",
+ dev_fwnode(parent));
+
+ fwnode_for_each_child_node(ports, port) {
+ struct device_node *mdio_dn;
+ u32 addr;
+ u32 bus;
+ u32 pn;
+
+ struct device_node *phy_dn __free(device_node) =
+ of_parse_phandle(to_of_node(port), "phy-handle", 0);
+ /* skip ports without phys */
+ if (!phy_dn)
+ continue;
+
+ mdio_dn = phy_dn->parent;
+ /* only map ports that are connected to this mdio-controller */
+ if (mdio_dn->parent != dev->of_node)
+ continue;
+
+ err = fwnode_property_read_u32(port, "reg", &pn);
+ if (err)
+ return err;
+
+ if (pn >= MAX_PORTS)
+ return dev_err_probe(dev, -EINVAL, "illegal port number %d\n", pn);
+
+ err = of_property_read_u32(mdio_dn, "reg", &bus);
+ if (err)
+ return err;
+
+ if (bus >= MAX_SMI_BUSSES)
+ return dev_err_probe(dev, -EINVAL, "illegal smi bus number %d\n", bus);
+
+ err = of_property_read_u32(phy_dn, "reg", &addr);
+ if (err)
+ return err;
+
+ bitmap_set(priv->valid_ports, pn, 1);
+ priv->smi_bus[pn] = bus;
+ priv->smi_addr[pn] = addr;
+ }
+
+ return 0;
+}
+
+static int rtl9300_mdiobus_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rtl9300_mdio_priv *priv;
+ struct fwnode_handle *child;
+ int err;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ err = devm_mutex_init(dev, &priv->lock);
+ if (err)
+ return err;
+
+ priv->regmap = syscon_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ platform_set_drvdata(pdev, priv);
+
+ err = rtl9300_mdiobus_map_ports(dev);
+ if (err)
+ return err;
+
+ device_for_each_child_node(dev, child) {
+ err = rtl9300_mdiobus_probe_one(dev, priv, child);
+ if (err)
+ return err;
+ }
+
+ err = rtl9300_mdiobus_init(priv);
+ if (err)
+ return dev_err_probe(dev, err, "failed to initialise MDIO bus controller\n");
+
+ return 0;
+}
+
+static const struct of_device_id rtl9300_mdio_ids[] = {
+ { .compatible = "realtek,rtl9301-mdio" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, rtl9300_mdio_ids);
+
+static struct platform_driver rtl9300_mdio_driver = {
+ .probe = rtl9300_mdiobus_probe,
+ .driver = {
+ .name = "mdio-rtl9300",
+ .of_match_table = rtl9300_mdio_ids,
+ },
+};
+
+module_platform_driver(rtl9300_mdio_driver);
+
+MODULE_DESCRIPTION("RTL9300 MDIO driver");
+MODULE_LICENSE("GPL");
--
2.48.1
^ permalink raw reply related [flat|nested] 4+ messages in thread