Add MDIO driver model support

From: Ken Ma <[email protected]>

This patch adds a separate driver for the MDIO interface of the Marvell Ethernet controllers based on driver model. There are two reasons to have a separate driver rather than including it inside the MAC driver itself:
*) The MDIO interface is shared by all Ethernet ports, so a driver
must guarantee non-concurrent accesses to this MDIO interface. The most logical way is to have a separate driver that handles this single MDIO interface, used by all Ethernet ports.
*) The MDIO interface is the same between the existing mv643xx_eth
driver and the new mvneta/mvpp2 driver. Even though it is for now only used by the mvneta/mvpp2 driver, it will in the future be used by the mv643xx_eth driver as well.

This driver supports SMI IEEE for 802.3 Clause 22 and XSMI for IEEE 802.3 Clause 45.

This patch also adds device tree binding for marvell MDIO driver.

Signed-off-by Ken Ma <[email protected]>

Reviewed-by Chris Packham <[email protected]>

---

Changes in v3:
- Move marvell mdio driver to driver/net/mdio folder;
- Update codes according to mdio uclass implementation updates.

Changes in v2:
- Fix error printing:
- Change some debug to pr_err;
- mii bus has no parent member and it is not a udevice, so dev_err is changed to pr_err for mii bus error printings.

  MAINTAINERS                                   |   1 +
  arch/arm/Kconfig                              |   1 +
  doc/device-tree-bindings/net/marvell-mdio.txt |  18 ++
  drivers/net/mdio/Kconfig                      |  10 ++
  drivers/net/mdio/Makefile                     |   1 +
  drivers/net/mdio/mvmdio.c                     | 234 ++++++++++++++++++++++++++
  6 files changed, 265 insertions(+)

create mode 100644 doc/device-tree-bindings/net/marvell-mdio.txt create mode 100644 drivers/net/mdio/mvmdio.c

MAINTAINERS +1 -0

index 9e1fc83..d8584f9 100644
@@ -137,6 +137,7 @@ T:	git git://git.denx.de/u-boot-marvell.git
  F:	arch/arm/mach-kirkwood/
  F:	arch/arm/mach-mvebu/
  F:	drivers/ata/ahci_mvebu.c
+F:	drivers/net/mdio/mvmdio.c
 
  ARM MARVELL PXA
  M:	Marek Vasut <[email protected]>

arch/arm/Kconfig +1 -0

index dde422b..e52b164 100644
@@ -432,6 +432,7 @@ config ARCH_MVEBU
  	select DM_SPI
  	select DM_SPI_FLASH
  	select SPI
+	select MDIO
 
  config TARGET_DEVKIT3250
  	bool "Support devkit3250"

doc/device-tree-bindings/net/marvell-mdio.txt new file +18 -0

new file mode 100644
index 0000000..55db435
@@ -0,0 +1,18 @@
+* Marvell MDIO Ethernet Controller interface
+
+The Ethernet controllers of the Marvel Armada 3700 and Armada 7k/8k
+have an identical unit that provides an interface with the MDIO bus.
+This driver handles this MDIO interface.
+
+Mandatory properties:
+SoC specific:
+	- #address-cells: Must be <1>.
+	- #size-cells: Must be <0>.
+	- compatible: Should be "marvell,orion-mdio" (for SMI)
+				"marvell,xmdio"	     (for XSMI)
+	- reg: Base address and size SMI/XMSI bus.
+
+Optional properties:
+	- mdio-name       - MDIO bus name
+
+For example, please refer to "mdio-bus.txt".

drivers/net/mdio/Kconfig +10 -0

index 533cc4a..d1a31e6 100644
@@ -15,4 +15,14 @@ config MDIO
  	  udevice or mii bus from its child phy node or
  	  an ethernet udevice which the phy belongs to.
 
+config MVMDIO
+	bool "Marvell MDIO interface support"
+	depends on MDIO
+	select PHYLIB
+	help
+	  This driver supports the MDIO interface found in the network
+	  interface units of the Marvell EBU SoCs (Kirkwood, Orion5x,
+	  Dove, Armada 370, Armada XP, Armada 37xx and Armada7K/8K/8KP).
+
+	  This driver is used by the MVPP2 and MVNETA drivers.
  endmenu

drivers/net/mdio/Makefile +1 -0

index 45ae502..8b2e5a4 100644
@@ -4,3 +4,4 @@
  # Author: Ken Ma<[email protected]>
 
  obj-$(CONFIG_MDIO) += mdio-uclass.o
+obj-$(CONFIG_MVMDIO) += mvmdio.o

drivers/net/mdio/mvmdio.c new file +51 -0

new file mode 100644
index 0000000..0fb45ce
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Marvell International Ltd.
+ * Author: Ken Ma<[email protected]>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <miiphy.h>
+#include <phy.h>
+#include <asm/io.h>
+
+#define MVMDIO_SMI_DATA_SHIFT		0
+#define MVMDIO_SMI_PHY_ADDR_SHIFT	16
+#define MVMDIO_SMI_PHY_REG_SHIFT	21
+#define MVMDIO_SMI_READ_OPERATION	BIT(26)
+#define MVMDIO_SMI_WRITE_OPERATION	0
+#define MVMDIO_SMI_READ_VALID		BIT(27)
+#define MVMDIO_SMI_BUSY			BIT(28)
+
+#define MVMDIO_XSMI_MGNT_REG		0x0
+#define MVMDIO_XSMI_PHYADDR_SHIFT	16
+#define MVMDIO_XSMI_DEVADDR_SHIFT	21
+#define MVMDIO_XSMI_WRITE_OPERATION	(0x5 << 26)
+#define MVMDIO_XSMI_READ_OPERATION	(0x7 << 26)
+#define MVMDIO_XSMI_READ_VALID		BIT(29)
+#define MVMDIO_XSMI_BUSY		BIT(30)
+#define MVMDIO_XSMI_ADDR_REG		0x8
+
+#define MVMDIO_TIMEOUT			10000
+
+struct mvmdio_priv {
+	void *mdio_base;
+};
+
+enum mvmdio_bus_type {
+	BUS_TYPE_SMI,
+	BUS_TYPE_XSMI
+};
+
+/* Wait for the SMI unit to be ready for another operation */
+static int mvmdio_smi_wait_ready(struct mii_dev *bus)
+{
+	u32 timeout = MVMDIO_TIMEOUT;
+	struct mvmdio_priv *priv = bus->priv;
+	u32 smi_reg;
+
+	/* Wait till the SMI is not busy */
+	do {

drivers/net/mdio/mvmdio.c new file +63 -0

+
+static int mvmdio_smi_read(struct mii_dev *bus, int addr,
+			   int devad, int reg)
+{
+	struct mvmdio_priv *priv = bus->priv;
+	u32 val;
+	int ret;
+
+	if (devad != MDIO_DEVAD_NONE)
+		return -EOPNOTSUPP;
+
+	ret = mvmdio_smi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	writel(((addr << MVMDIO_SMI_PHY_ADDR_SHIFT) |
+		(reg << MVMDIO_SMI_PHY_REG_SHIFT)  |
+		MVMDIO_SMI_READ_OPERATION),
+	       priv->mdio_base);
+
+	ret = mvmdio_smi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	val = readl(priv->mdio_base);
+	if (!(val & MVMDIO_SMI_READ_VALID)) {
+		pr_err("SMI bus read not valid\n");
+		return -ENODEV;
+	}
+
+	return val & GENMASK(15, 0);
+}
+
+static int mvmdio_smi_write(struct mii_dev *bus, int addr, int devad,
+			    int reg, u16 value)
+{
+	struct mvmdio_priv *priv = bus->priv;
+	int ret;
+
+	if (devad != MDIO_DEVAD_NONE)
+		return -EOPNOTSUPP;
+
+	ret = mvmdio_smi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	writel(((addr << MVMDIO_SMI_PHY_ADDR_SHIFT) |
+		(reg << MVMDIO_SMI_PHY_REG_SHIFT)  |
+		MVMDIO_SMI_WRITE_OPERATION            |
+		(value << MVMDIO_SMI_DATA_SHIFT)),
+	       priv->mdio_base);
+
+	return 0;
+}
+
+static int mvmdio_xsmi_wait_ready(struct mii_dev *bus)
+{
+	u32 timeout = MVMDIO_TIMEOUT;
+	struct mvmdio_priv *priv = bus->priv;
+	u32 xsmi_reg;
+
+	/* Wait till the xSMI is not busy */
+	do {