net: dsa: b53: Add support for Broadcom RoboSwitch

This patch adds support for Broadcom's BCM53xx switch family, also known
as RoboSwitch. Some of these switches are ubiquituous, found in home
routers, Wi-Fi routers, DSL and cable modem gateways and other
networking related products.

This drivers adds the library driver (b53_common.c) as well as a few bus
glue drivers for MDIO, SPI, Switch Register Access Block (SRAB) and
memory-mapped I/O into a SoC's address space (Broadcom BCM63xx/33xx).

Basic operations are supported to bring the Layer 1/2 up and running,
but not much more at this point, subsequent patches add the remaining
features.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/b53/b53_mdio.c b/drivers/net/dsa/b53/b53_mdio.c
new file mode 100644
index 0000000..c6cf7cf
--- /dev/null
+++ b/drivers/net/dsa/b53/b53_mdio.c
@@ -0,0 +1,381 @@
+/*
+ * B53 register access through MII registers
+ *
+ * Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/phy.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/brcmphy.h>
+#include <linux/rtnetlink.h>
+#include <net/dsa.h>
+
+#include "b53_priv.h"
+
+/* MII registers */
+#define REG_MII_PAGE    0x10    /* MII Page register */
+#define REG_MII_ADDR    0x11    /* MII Address register */
+#define REG_MII_DATA0   0x18    /* MII Data register 0 */
+#define REG_MII_DATA1   0x19    /* MII Data register 1 */
+#define REG_MII_DATA2   0x1a    /* MII Data register 2 */
+#define REG_MII_DATA3   0x1b    /* MII Data register 3 */
+
+#define REG_MII_PAGE_ENABLE     BIT(0)
+#define REG_MII_ADDR_WRITE      BIT(0)
+#define REG_MII_ADDR_READ       BIT(1)
+
+static int b53_mdio_op(struct b53_device *dev, u8 page, u8 reg, u16 op)
+{
+	int i;
+	u16 v;
+	int ret;
+	struct mii_bus *bus = dev->priv;
+
+	if (dev->current_page != page) {
+		/* set page number */
+		v = (page << 8) | REG_MII_PAGE_ENABLE;
+		ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					   REG_MII_PAGE, v);
+		if (ret)
+			return ret;
+		dev->current_page = page;
+	}
+
+	/* set register address */
+	v = (reg << 8) | op;
+	ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR, REG_MII_ADDR, v);
+	if (ret)
+		return ret;
+
+	/* check if operation completed */
+	for (i = 0; i < 5; ++i) {
+		v = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					REG_MII_ADDR);
+		if (!(v & (REG_MII_ADDR_WRITE | REG_MII_ADDR_READ)))
+			break;
+		usleep_range(10, 100);
+	}
+
+	if (WARN_ON(i == 5))
+		return -EIO;
+
+	return 0;
+}
+
+static int b53_mdio_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
+{
+	struct mii_bus *bus = dev->priv;
+	int ret;
+
+	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
+	if (ret)
+		return ret;
+
+	*val = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+				   REG_MII_DATA0) & 0xff;
+
+	return 0;
+}
+
+static int b53_mdio_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
+{
+	struct mii_bus *bus = dev->priv;
+	int ret;
+
+	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
+	if (ret)
+		return ret;
+
+	*val = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR, REG_MII_DATA0);
+
+	return 0;
+}
+
+static int b53_mdio_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
+{
+	struct mii_bus *bus = dev->priv;
+	int ret;
+
+	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
+	if (ret)
+		return ret;
+
+	*val = mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR, REG_MII_DATA0);
+	*val |= mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+				    REG_MII_DATA1) << 16;
+
+	return 0;
+}
+
+static int b53_mdio_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
+{
+	struct mii_bus *bus = dev->priv;
+	u64 temp = 0;
+	int i;
+	int ret;
+
+	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
+	if (ret)
+		return ret;
+
+	for (i = 2; i >= 0; i--) {
+		temp <<= 16;
+		temp |= mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+				     REG_MII_DATA0 + i);
+	}
+
+	*val = temp;
+
+	return 0;
+}
+
+static int b53_mdio_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
+{
+	struct mii_bus *bus = dev->priv;
+	u64 temp = 0;
+	int i;
+	int ret;
+
+	ret = b53_mdio_op(dev, page, reg, REG_MII_ADDR_READ);
+	if (ret)
+		return ret;
+
+	for (i = 3; i >= 0; i--) {
+		temp <<= 16;
+		temp |= mdiobus_read_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					    REG_MII_DATA0 + i);
+	}
+
+	*val = temp;
+
+	return 0;
+}
+
+static int b53_mdio_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
+{
+	struct mii_bus *bus = dev->priv;
+	int ret;
+
+	ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+				   REG_MII_DATA0, value);
+	if (ret)
+		return ret;
+
+	return b53_mdio_op(dev, page, reg, REG_MII_ADDR_WRITE);
+}
+
+static int b53_mdio_write16(struct b53_device *dev, u8 page, u8 reg,
+			    u16 value)
+{
+	struct mii_bus *bus = dev->priv;
+	int ret;
+
+	ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+				   REG_MII_DATA0, value);
+	if (ret)
+		return ret;
+
+	return b53_mdio_op(dev, page, reg, REG_MII_ADDR_WRITE);
+}
+
+static int b53_mdio_write32(struct b53_device *dev, u8 page, u8 reg,
+			    u32 value)
+{
+	struct mii_bus *bus = dev->priv;
+	unsigned int i;
+	u32 temp = value;
+
+	for (i = 0; i < 2; i++) {
+		int ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					       REG_MII_DATA0 + i,
+					       temp & 0xffff);
+		if (ret)
+			return ret;
+		temp >>= 16;
+	}
+
+	return b53_mdio_op(dev, page, reg, REG_MII_ADDR_WRITE);
+}
+
+static int b53_mdio_write48(struct b53_device *dev, u8 page, u8 reg,
+			    u64 value)
+{
+	struct mii_bus *bus = dev->priv;
+	unsigned int i;
+	u64 temp = value;
+
+	for (i = 0; i < 3; i++) {
+		int ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					       REG_MII_DATA0 + i,
+					       temp & 0xffff);
+		if (ret)
+			return ret;
+		temp >>= 16;
+	}
+
+	return b53_mdio_op(dev, page, reg, REG_MII_ADDR_WRITE);
+}
+
+static int b53_mdio_write64(struct b53_device *dev, u8 page, u8 reg,
+			    u64 value)
+{
+	struct mii_bus *bus = dev->priv;
+	unsigned int i;
+	u64 temp = value;
+
+	for (i = 0; i < 4; i++) {
+		int ret = mdiobus_write_nested(bus, BRCM_PSEUDO_PHY_ADDR,
+					       REG_MII_DATA0 + i,
+					       temp & 0xffff);
+		if (ret)
+			return ret;
+		temp >>= 16;
+	}
+
+	return b53_mdio_op(dev, page, reg, REG_MII_ADDR_WRITE);
+}
+
+static int b53_mdio_phy_read16(struct b53_device *dev, int addr, int reg,
+			       u16 *value)
+{
+	struct mii_bus *bus = dev->priv;
+
+	*value = mdiobus_read_nested(bus, addr, reg);
+
+	return 0;
+}
+
+static int b53_mdio_phy_write16(struct b53_device *dev, int addr, int reg,
+				u16 value)
+{
+	struct mii_bus *bus = dev->bus;
+
+	return mdiobus_write_nested(bus, addr, reg, value);
+}
+
+static struct b53_io_ops b53_mdio_ops = {
+	.read8 = b53_mdio_read8,
+	.read16 = b53_mdio_read16,
+	.read32 = b53_mdio_read32,
+	.read48 = b53_mdio_read48,
+	.read64 = b53_mdio_read64,
+	.write8 = b53_mdio_write8,
+	.write16 = b53_mdio_write16,
+	.write32 = b53_mdio_write32,
+	.write48 = b53_mdio_write48,
+	.write64 = b53_mdio_write64,
+	.phy_read16 = b53_mdio_phy_read16,
+	.phy_write16 = b53_mdio_phy_write16,
+};
+
+#define B53_BRCM_OUI_1	0x0143bc00
+#define B53_BRCM_OUI_2	0x03625c00
+#define B53_BRCM_OUI_3	0x00406000
+
+static int b53_mdio_probe(struct mdio_device *mdiodev)
+{
+	struct b53_device *dev;
+	u32 phy_id;
+	int ret;
+
+	/* allow the generic PHY driver to take over the non-management MDIO
+	 * addresses
+	 */
+	if (mdiodev->addr != BRCM_PSEUDO_PHY_ADDR && mdiodev->addr != 0) {
+		dev_err(&mdiodev->dev, "leaving address %d to PHY\n",
+			mdiodev->addr);
+		return -ENODEV;
+	}
+
+	/* read the first port's id */
+	phy_id = mdiobus_read(mdiodev->bus, 0, 2) << 16;
+	phy_id |= mdiobus_read(mdiodev->bus, 0, 3);
+
+	/* BCM5325, BCM539x (OUI_1)
+	 * BCM53125, BCM53128 (OUI_2)
+	 * BCM5365 (OUI_3)
+	 */
+	if ((phy_id & 0xfffffc00) != B53_BRCM_OUI_1 &&
+	    (phy_id & 0xfffffc00) != B53_BRCM_OUI_2 &&
+	    (phy_id & 0xfffffc00) != B53_BRCM_OUI_3) {
+		dev_err(&mdiodev->dev, "Unsupported device: 0x%08x\n", phy_id);
+		return -ENODEV;
+	}
+
+	dev = b53_switch_alloc(&mdiodev->dev, &b53_mdio_ops, mdiodev->bus);
+	if (!dev)
+		return -ENOMEM;
+
+	/* we don't use page 0xff, so force a page set */
+	dev->current_page = 0xff;
+	dev->bus = mdiodev->bus;
+
+	dev_set_drvdata(&mdiodev->dev, dev);
+
+	ret = b53_switch_register(dev);
+	if (ret) {
+		dev_err(&mdiodev->dev, "failed to register switch: %i\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void b53_mdio_remove(struct mdio_device *mdiodev)
+{
+	struct b53_device *dev = dev_get_drvdata(&mdiodev->dev);
+	struct dsa_switch *ds = dev->ds;
+
+	dsa_unregister_switch(ds);
+}
+
+static const struct of_device_id b53_of_match[] = {
+	{ .compatible = "brcm,bcm5325" },
+	{ .compatible = "brcm,bcm53115" },
+	{ .compatible = "brcm,bcm53125" },
+	{ .compatible = "brcm,bcm53128" },
+	{ .compatible = "brcm,bcm5365" },
+	{ .compatible = "brcm,bcm5395" },
+	{ .compatible = "brcm,bcm5397" },
+	{ .compatible = "brcm,bcm5398" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, b53_of_match);
+
+static struct mdio_driver b53_mdio_driver = {
+	.probe	= b53_mdio_probe,
+	.remove	= b53_mdio_remove,
+	.mdiodrv.driver = {
+		.name = "bcm53xx",
+		.of_match_table = b53_of_match,
+	},
+};
+
+static int __init b53_mdio_driver_register(void)
+{
+	return mdio_driver_register(&b53_mdio_driver);
+}
+module_init(b53_mdio_driver_register);
+
+static void __exit b53_mdio_driver_unregister(void)
+{
+	mdio_driver_unregister(&b53_mdio_driver);
+}
+module_exit(b53_mdio_driver_unregister);
+
+MODULE_DESCRIPTION("B53 MDIO access driver");
+MODULE_LICENSE("Dual BSD/GPL");