[PATCH net-next v11 09/10] net: mdio: realtek-rtl9300: Add support for RTL838x

[Markus Stockhausen <markus.stockhausen@gmx.de>]

The MDIO driver has been prepared for multiple device support. Add all
required bits for the RTL838x (aka maple) series. This is straightforward
but some things are worth mentioning.

- The device has a lot in common with the RTL930x series. It has 28 ports,
  4096 (Realtek) pages and 4 MMIO registers. With this a lot of the
  existing RTL9300 defines could be reused. But to avoid confusion and
  for better readability duplicate the defines with a proper prefix.
- The MDIO engine has no fail bit. Thus the mask is set to zero.
- There is only one SMI bus for 1G PHYs. No bus_map_base register exists.
- The setup_controller() function needs no c45 setup but must activate
  the PHY access.

As per the SDK the PHYs on a RTl83xx bus are mainly c22 driven. The
polling unit works in c22 mode and the devicetree usually does not
make use of the ethernet-phy-ieee802.3-c45 flag. Nevertheless there are
some PHY MMD registers (e.g. EEE) that might be of interest for the
future development of the hardware. For completeness and extendability
the c45 read/write functions are already implemented with this commit.
Just like for the RTL93xx devices. But in contrast to them RTL83xx knows
no flag to switch the polling engine between the two modes.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
---
 drivers/net/mdio/mdio-realtek-rtl9300.c | 108 ++++++++++++++++++++++++
 1 file changed, 108 insertions(+)

diff --git a/drivers/net/mdio/mdio-realtek-rtl9300.c b/drivers/net/mdio/mdio-realtek-rtl9300.c
index dc30412a1af9..6a47f872a352 100644
--- a/drivers/net/mdio/mdio-realtek-rtl9300.c
+++ b/drivers/net/mdio/mdio-realtek-rtl9300.c
@@ -125,6 +125,28 @@
 #include <linux/property.h>
 #include <linux/regmap.h>
 
+#define RTL8380_NUM_BUSES			1
+#define RTL8380_NUM_PAGES			4096
+#define RTL8380_NUM_PORTS			28
+#define RTL8380_SMI_GLB_CTRL			0xa100
+#define   RTL8380_SMI_PHY_PATCH_DONE		BIT(15)
+#define RTL8380_SMI_ACCESS_PHY_CTRL_0		0xa1b8
+#define RTL8380_SMI_ACCESS_PHY_CTRL_1		0xa1bc
+#define   RTL8380_PHY_CTRL_REG_ADDR		GENMASK(24, 20)
+#define   RTL8380_PHY_CTRL_PARK_PAGE		GENMASK(19, 15)
+#define   RTL8380_PHY_CTRL_MAIN_PAGE		GENMASK(14, 3)
+#define   RTL8380_PHY_CTRL_WRITE		BIT(2)
+#define   RTL8380_PHY_CTRL_READ			0
+#define   RTL8380_PHY_CTRL_TYPE_C45		BIT(1)
+#define   RTL8380_PHY_CTRL_TYPE_C22		0
+#define   RTL8380_PHY_CTRL_FAIL			0 /* no fail indicator */
+#define RTL8380_SMI_ACCESS_PHY_CTRL_2		0xa1c0
+#define   RTL8380_PHY_CTRL_INDATA		GENMASK(31, 16)
+#define   RTL8380_PHY_CTRL_DATA			GENMASK(15, 0)
+#define RTL8380_SMI_ACCESS_PHY_CTRL_3		0xa1c4
+#define RTL8380_SMI_POLL_CTRL			0xa17c
+#define RTL8380_SMI_PORT0_5_ADDR_CTRL		0xa1c8
+
 #define RTL9300_NUM_BUSES			4
 #define RTL9300_NUM_PAGES			4096
 #define RTL9300_NUM_PORTS			28
@@ -352,6 +374,60 @@ static int otto_emdio_write_cmd(struct mii_bus *bus, u32 cmd,
 	return otto_emdio_run_cmd(bus, cmd | priv->info->cmd_write, cmd_data);
 }
 
+static int otto_emdio_8380_read_c22(struct mii_bus *bus, int port, int regnum, u32 *value)
+{
+	struct otto_emdio_priv *priv = otto_emdio_bus_to_priv(bus);
+	struct otto_emdio_cmd_regs cmd_data = {
+		.c22_data	= FIELD_PREP(RTL8380_PHY_CTRL_REG_ADDR, regnum) |
+				  FIELD_PREP(RTL8380_PHY_CTRL_PARK_PAGE, 0x1f) |
+				  FIELD_PREP(RTL8380_PHY_CTRL_MAIN_PAGE, priv->page[port]),
+		.io_data	= FIELD_PREP(RTL8380_PHY_CTRL_INDATA, port),
+	};
+
+	return otto_emdio_read_cmd(bus, RTL8380_PHY_CTRL_TYPE_C22, &cmd_data,
+				   RTL8380_PHY_CTRL_DATA, value);
+}
+
+static int otto_emdio_8380_write_c22(struct mii_bus *bus, int port, int regnum, u16 value)
+{
+	struct otto_emdio_priv *priv = otto_emdio_bus_to_priv(bus);
+	struct otto_emdio_cmd_regs cmd_data = {
+		.c22_data	= FIELD_PREP(RTL8380_PHY_CTRL_REG_ADDR, regnum) |
+				  FIELD_PREP(RTL8380_PHY_CTRL_PARK_PAGE, 0x1f) |
+				  FIELD_PREP(RTL8380_PHY_CTRL_MAIN_PAGE, priv->page[port]),
+		.io_data	= FIELD_PREP(RTL8380_PHY_CTRL_INDATA, value),
+		.port_mask_low	= BIT(port),
+	};
+
+	return otto_emdio_write_cmd(bus, RTL8380_PHY_CTRL_TYPE_C22, &cmd_data);
+}
+
+static int otto_emdio_8380_read_c45(struct mii_bus *bus, int port,
+				    int dev_addr, int regnum, u32 *value)
+{
+	struct otto_emdio_cmd_regs cmd_data = {
+		.c45_data	= FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) |
+				  FIELD_PREP(PHY_CTRL_MMD_REG, regnum),
+		.io_data	= FIELD_PREP(RTL8380_PHY_CTRL_INDATA, port),
+	};
+
+	return otto_emdio_read_cmd(bus, RTL8380_PHY_CTRL_TYPE_C45, &cmd_data,
+				   RTL8380_PHY_CTRL_DATA, value);
+}
+
+static int otto_emdio_8380_write_c45(struct mii_bus *bus, int port,
+				     int dev_addr, int regnum, u16 value)
+{
+	struct otto_emdio_cmd_regs cmd_data = {
+		.c45_data	= FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) |
+				  FIELD_PREP(PHY_CTRL_MMD_REG, regnum),
+		.io_data	= FIELD_PREP(RTL8380_PHY_CTRL_INDATA, value),
+		.port_mask_low	= BIT(port),
+	};
+
+	return otto_emdio_write_cmd(bus, RTL8380_PHY_CTRL_TYPE_C45, &cmd_data);
+}
+
 static int otto_emdio_9300_read_c22(struct mii_bus *bus, int port, int regnum, u32 *value)
 {
 	struct otto_emdio_priv *priv = otto_emdio_bus_to_priv(bus);
@@ -572,6 +648,15 @@ static int otto_emdio_setup_topology(struct otto_emdio_priv *priv)
 	return 0;
 }
 
+static int otto_emdio_8380_setup_controller(struct otto_emdio_priv *priv)
+{
+	/*
+	 * PHY_PATCH_DONE enables PHY control via SoC. This is required for PHY access, including
+	 * patching and must be set before the PHYs are probed.
+	 */
+	return regmap_set_bits(priv->regmap, RTL8380_SMI_GLB_CTRL, RTL8380_SMI_PHY_PATCH_DONE);
+}
+
 static int otto_emdio_9300_setup_controller(struct otto_emdio_priv *priv)
 {
 	u32 glb_ctrl_mask = 0, glb_ctrl_val = 0;
@@ -863,6 +948,28 @@ static int otto_emdio_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct otto_emdio_info otto_emdio_8380_info = {
+	.addr_map_base = RTL8380_SMI_PORT0_5_ADDR_CTRL,
+	.cmd_fail = RTL8380_PHY_CTRL_FAIL,
+	.cmd_read = RTL8380_PHY_CTRL_READ,
+	.cmd_write = RTL8380_PHY_CTRL_WRITE,
+	.cmd_regs = {
+		.c22_data = RTL8380_SMI_ACCESS_PHY_CTRL_1,
+		.c45_data = RTL8380_SMI_ACCESS_PHY_CTRL_3,
+		.io_data = RTL8380_SMI_ACCESS_PHY_CTRL_2,
+		.port_mask_low = RTL8380_SMI_ACCESS_PHY_CTRL_0,
+	},
+	.num_buses = RTL8380_NUM_BUSES,
+	.num_pages = RTL8380_NUM_PAGES,
+	.num_ports = RTL8380_NUM_PORTS,
+	.poll_ctrl = RTL8380_SMI_POLL_CTRL,
+	.setup_controller = otto_emdio_8380_setup_controller,
+	.read_c22 = otto_emdio_8380_read_c22,
+	.read_c45 = otto_emdio_8380_read_c45,
+	.write_c22 = otto_emdio_8380_write_c22,
+	.write_c45 = otto_emdio_8380_write_c45,
+};
+
 static const struct otto_emdio_info otto_emdio_9300_info = {
 	.addr_map_base = RTL9300_SMI_PORT0_5_ADDR_CTRL,
 	.bus_map_base = RTL9300_SMI_PORT0_15_POLLING_SEL,
@@ -913,6 +1020,7 @@ static const struct otto_emdio_info otto_emdio_9310_info = {
 };
 
 static const struct of_device_id otto_emdio_ids[] = {
+	{ .compatible = "realtek,rtl8380-mdio", .data = &otto_emdio_8380_info },
 	{ .compatible = "realtek,rtl9301-mdio", .data = &otto_emdio_9300_info },
 	{ .compatible = "realtek,rtl9311-mdio", .data = &otto_emdio_9310_info },
 	{}
-- 
2.55.0