[U-Boot] [PATCH v2 2/2] mdio: add marvell MDIO driver

[make at marvell.com <make@marvell.com>]

From: Ken Ma <make@marvell.com>

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 <make@marvell.com>
---

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/mdio/marvell-mdio.txt |  18 ++
 drivers/mdio/Kconfig                           |  10 ++
 drivers/mdio/Makefile                          |   1 +
 drivers/mdio/mvmdio.c                          | 237 +++++++++++++++++++++++++
 6 files changed, 268 insertions(+)
 create mode 100644 doc/device-tree-bindings/mdio/marvell-mdio.txt
 create mode 100644 drivers/mdio/mvmdio.c

diff --git a/MAINTAINERS b/MAINTAINERS
index f66a904..fb58f17 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -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/mdio/mvmdio.c
 
 ARM MARVELL PXA
 M:	Marek Vasut <marex@denx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dde422b..aae4570 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -432,6 +432,7 @@ config ARCH_MVEBU
 	select DM_SPI
 	select DM_SPI_FLASH
 	select SPI
+	select DM_MDIO
 
 config TARGET_DEVKIT3250
 	bool "Support devkit3250"
diff --git a/doc/device-tree-bindings/mdio/marvell-mdio.txt b/doc/device-tree-bindings/mdio/marvell-mdio.txt
new file mode 100644
index 0000000..55db435
--- /dev/null
+++ b/doc/device-tree-bindings/mdio/marvell-mdio.txt
@@ -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".
diff --git a/drivers/mdio/Kconfig b/drivers/mdio/Kconfig
index 76e3758..ce251c5 100644
--- a/drivers/mdio/Kconfig
+++ b/drivers/mdio/Kconfig
@@ -15,4 +15,14 @@ config DM_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 DM_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
diff --git a/drivers/mdio/Makefile b/drivers/mdio/Makefile
index 9b290c0..9f571aa 100644
--- a/drivers/mdio/Makefile
+++ b/drivers/mdio/Makefile
@@ -4,3 +4,4 @@
 # Author: Ken Ma<make@marvell.com>
 
 obj-$(CONFIG_DM_MDIO) += mdio-uclass.o
+obj-$(CONFIG_MVMDIO) += mvmdio.o
diff --git a/drivers/mdio/mvmdio.c b/drivers/mdio/mvmdio.c
new file mode 100644
index 0000000..2771d32
--- /dev/null
+++ b/drivers/mdio/mvmdio.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Marvell International Ltd.
+ * Author: Ken Ma<make@marvell.com>
+ */
+
+#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>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#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 {
+		/* Read smi register */
+		smi_reg = readl(priv->mdio_base);
+		if (timeout-- == 0) {
+			pr_err("Error: SMI busy timeout\n");
+			return -ETIME;
+		}
+	} while (smi_reg & MVMDIO_SMI_BUSY);
+
+	return 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 {
+		/* Read xSMI register */
+		xsmi_reg = readl(priv->mdio_base);
+		if (timeout-- == 0) {
+			pr_err("xSMI busy time-out\n");
+			return -ETIME;
+		}
+	} while (xsmi_reg & MVMDIO_XSMI_BUSY);
+
+	return 0;
+}
+
+static int mvmdio_xsmi_read(struct mii_dev *bus, int addr,
+			    int devad, int reg)
+{
+	struct mvmdio_priv *priv = bus->priv;
+	int ret;
+
+	if (devad == MDIO_DEVAD_NONE)
+		return -EOPNOTSUPP;
+
+	ret = mvmdio_xsmi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	writel(reg & GENMASK(15, 0), priv->mdio_base + MVMDIO_XSMI_ADDR_REG);
+	writel(((addr << MVMDIO_XSMI_PHYADDR_SHIFT) |
+		(devad << MVMDIO_XSMI_DEVADDR_SHIFT) |
+		MVMDIO_XSMI_READ_OPERATION),
+	       priv->mdio_base + MVMDIO_XSMI_MGNT_REG);
+
+	ret = mvmdio_xsmi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	if (!(readl(priv->mdio_base + MVMDIO_XSMI_MGNT_REG) &
+	      MVMDIO_XSMI_READ_VALID)) {
+		pr_err("XSMI bus read not valid\n");
+		return -ENODEV;
+	}
+
+	return readl(priv->mdio_base + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
+}
+
+static int mvmdio_xsmi_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_xsmi_wait_ready(bus);
+	if (ret < 0)
+		return ret;
+
+	writel(reg & GENMASK(15, 0), priv->mdio_base + MVMDIO_XSMI_ADDR_REG);
+	writel(((addr << MVMDIO_XSMI_PHYADDR_SHIFT) |
+		(devad << MVMDIO_XSMI_DEVADDR_SHIFT) |
+		MVMDIO_XSMI_WRITE_OPERATION | value),
+	       priv->mdio_base + MVMDIO_XSMI_MGNT_REG);
+
+	return 0;
+}
+
+static int mvmdio_probe(struct udevice *dev)
+{
+	struct mii_dev **pbus = dev_get_uclass_platdata(dev);
+	struct mii_dev *bus = *pbus;
+	struct mvmdio_priv *priv;
+	enum mvmdio_bus_type type;
+
+	priv = dev_get_priv(dev);
+	priv->mdio_base = (void *)devfdt_get_addr(dev);
+	bus->priv = priv;
+
+	type = (enum mvmdio_bus_type)dev_get_driver_data(dev);
+	switch (type) {
+	case BUS_TYPE_SMI:
+		bus->read = mvmdio_smi_read;
+		bus->write = mvmdio_smi_write;
+		if (!bus->name)
+			snprintf(bus->name, MDIO_NAME_LEN,
+				 "orion-mdio.%p", priv->mdio_base);
+		break;
+	case BUS_TYPE_XSMI:
+		bus->read = mvmdio_xsmi_read;
+		bus->write = mvmdio_xsmi_write;
+		if (!bus->name)
+			snprintf(bus->name, MDIO_NAME_LEN,
+				 "xmdio.%p", priv->mdio_base);
+		break;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id mvmdio_ids[] = {
+	{ .compatible = "marvell,orion-mdio", .data = BUS_TYPE_SMI },
+	{ .compatible = "marvell,xmdio", .data = BUS_TYPE_XSMI },
+	{ }
+};
+
+U_BOOT_DRIVER(mvmdio) = {
+	.name			= "mvmdio",
+	.id			= UCLASS_MDIO,
+	.of_match		= mvmdio_ids,
+	.probe			= mvmdio_probe,
+	.priv_auto_alloc_size	= sizeof(struct mvmdio_priv),
+};
+
-- 
1.9.1