Merge branch 'for-next/mii'

5 files changed, 341 insertions, 0 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index ea2e062656..cda752b659 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -66,6 +66,24 @@ config MDIO_GPIO
 	---help---
 	  Supports GPIO lib-based MDIO busses.
 
+config MDIO_BUS_MUX
+	bool
+	help
+	  This module provides a driver framework for MDIO bus
+	  multiplexers which connect one of several child MDIO busses
+	  to a parent bus.  Switching between child busses is done by
+	  device specific drivers.
+
+config MDIO_BUS_MUX_GPIO
+	bool "GPIO controlled MDIO bus multiplexers"
+	depends on OF_GPIO
+	select MDIO_BUS_MUX
+	help
+	  This module provides a driver for MDIO bus multiplexers that
+	  are controlled via GPIO lines.  The multiplexer connects one of
+	  several child MDIO busses to a parent bus.  Child bus
+	  selection is under the control of GPIO lines.
+
 endif
 
 endmenu
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 13b8f6545d..30b20f8ee6 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -10,3 +10,6 @@ obj-$(CONFIG_SMSC_PHY)		+= smsc.o
 obj-$(CONFIG_MDIO_MVEBU)	+= mdio-mvebu.o
 obj-$(CONFIG_MDIO_BITBANG)	+= mdio-bitbang.o
 obj-$(CONFIG_MDIO_GPIO)		+= mdio-gpio.o
+obj-$(CONFIG_MDIO_BUS_MUX)	+= mdio-mux.o
+obj-$(CONFIG_MDIO_BUS_MUX_GPIO)	+= mdio-mux-gpio.o
+
diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c
new file mode 100644
index 0000000000..221353cbcb
--- /dev/null
+++ b/drivers/net/phy/mdio-mux-gpio.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2017 Zodiac Inflight Innovation
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * Based on analogous code from Linux kernel
+ *
+ * Copyright (C) 2011, 2012 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ */
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <linux/mdio-mux.h>
+#include <gpio.h>
+#include <of_gpio.h>
+
+
+struct mdio_mux_gpio_state {
+	struct gpio *gpios;
+	int gpios_num;
+};
+
+static void mdio_mux_gpio_set_active(struct mdio_mux_gpio_state *s,
+				     unsigned int mask, int value)
+{
+	while (mask) {
+		const int n = __ffs(mask);
+		mask >>= n + 1;
+
+		if (WARN_ON(n >= s->gpios_num))
+			break;
+
+		gpio_set_active(s->gpios[n].gpio, value);
+	}
+}
+
+static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
+				   void *data)
+{
+	if (current_child < 0)
+		current_child = 0;
+
+	if (current_child != desired_child) {
+		struct mdio_mux_gpio_state *s = data;
+		/*
+		 * GPIOs that are set in both current and desired
+		 * states can be left untouched. So we calculate them
+		 * and clear corresponding bits in both states.
+		 */
+		const int unchanged = current_child & desired_child;
+
+		current_child &= ~unchanged;
+		desired_child &= ~unchanged;
+
+		/*
+		 * First step: disable all of the currently selected
+		 * bits that are no loger needed
+		 */
+		mdio_mux_gpio_set_active(s, current_child, 0);
+		/*
+		 * Second step: enable all of the GPIOs that are
+		 * desired to be selected
+		 */
+		mdio_mux_gpio_set_active(s, desired_child, 1);
+	}
+
+	return 0;
+}
+
+static int mdio_mux_gpio_probe(struct device_d *dev)
+{
+	struct mdio_mux_gpio_state *s;
+	int i, r;
+
+	s = xzalloc(sizeof(*s));
+
+	s->gpios_num = of_gpio_count(dev->device_node);
+	if (s->gpios_num <= 0) {
+		dev_err(dev, "No GPIOs specified\n");
+		r = -EINVAL;
+		goto free_mem;
+	}
+
+	s->gpios = xzalloc(s->gpios_num * sizeof(s->gpios[0]));
+
+	for (i = 0; i < s->gpios_num; i++) {
+		enum of_gpio_flags flags;
+
+		r = of_get_gpio_flags(dev->device_node, i, &flags);
+		if (!gpio_is_valid(r)) {
+			r = (r < 0) ? r : -EINVAL;
+			goto free_mem;
+		}
+
+		s->gpios[i].gpio  = r;
+		s->gpios[i].label = dev_name(dev);
+		s->gpios[i].flags = GPIOF_OUT_INIT_INACTIVE;
+
+		if (flags & OF_GPIO_ACTIVE_LOW)
+			s->gpios[i].flags |= GPIOF_ACTIVE_LOW;
+	}
+
+	r = gpio_request_array(s->gpios, s->gpios_num);
+	if (r < 0)
+		goto free_gpios;
+
+
+	r = mdio_mux_init(dev, dev->device_node,
+			  mdio_mux_gpio_switch_fn, s, NULL);
+	if (r < 0)
+		goto free_gpios;
+
+	return 0;
+
+free_gpios:
+	gpio_free_array(s->gpios, s->gpios_num);
+free_mem:
+	free(s->gpios);
+	free(s);
+	return r;
+}
+
+static const struct of_device_id mdio_mux_gpio_match[] = {
+	{
+		.compatible = "mdio-mux-gpio",
+	},
+	{},
+};
+
+static struct driver_d mdio_mux_gpio_driver = {
+	.name	       = "mdio-mux-gpio",
+	.probe         = mdio_mux_gpio_probe,
+	.of_compatible = mdio_mux_gpio_match,
+};
+device_platform_driver(mdio_mux_gpio_driver);
diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
new file mode 100644
index 0000000000..1f57d86c6f
--- /dev/null
+++ b/drivers/net/phy/mdio-mux.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2017 Zodiac Inflight Innovation
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * Based on analogous code from Linux kernel
+ *
+ * Copyright (C) 2011, 2012 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <common.h>
+#include <linux/mdio-mux.h>
+#include <linux/phy.h>
+
+struct mdio_mux_parent_bus {
+	struct mii_bus *mii_bus;
+	int current_child;
+	int parent_id;
+	void *switch_data;
+	int (*switch_fn)(int current_child, int desired_child, void *data);
+};
+
+struct mdio_mux_child_bus {
+	struct mii_bus mii_bus;
+	struct mdio_mux_parent_bus *parent;
+	struct mdio_mux_child_bus *next;
+	int bus_number;
+};
+
+static int mdio_mux_read_or_write(struct mii_bus *bus, int phy_id,
+		       int regnum, u16 *val)
+{
+	struct mdio_mux_child_bus *cb = bus->priv;
+	struct mdio_mux_parent_bus *pb = cb->parent;
+	int r;
+
+	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
+	if (!r) {
+		pb->current_child = cb->bus_number;
+		if (val)
+			r = pb->mii_bus->write(pb->mii_bus, phy_id,
+					       regnum, *val);
+		else
+			r = pb->mii_bus->read(pb->mii_bus, phy_id,
+					      regnum);
+	}
+	return r;
+}
+
+static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)
+{
+	return mdio_mux_read_or_write(bus, phy_id, regnum, NULL);
+}
+
+static int mdio_mux_write(struct mii_bus *bus, int phy_id,
+			  int regnum, u16 val)
+{
+	return mdio_mux_read_or_write(bus, phy_id, regnum, &val);
+}
+
+int mdio_mux_init(struct device_d *dev,
+		  struct device_node *mux_node,
+		  int (*switch_fn)(int cur, int desired, void *data),
+		  void *data,
+		  struct mii_bus *mux_bus)
+{
+	static int parent_count = 0;
+
+	struct device_node *parent_bus_node;
+	struct device_node *child_bus_node;
+	struct mdio_mux_parent_bus *pb;
+	struct mdio_mux_child_bus *cb;
+	struct mii_bus *parent_bus;
+	int r;
+
+	if (!mux_node)
+		return -ENODEV;
+
+	if (!mux_bus) {
+		parent_bus_node = of_parse_phandle(mux_node,
+						   "mdio-parent-bus", 0);
+
+		if (!parent_bus_node)
+			return -ENODEV;
+
+		parent_bus = of_mdio_find_bus(parent_bus_node);
+
+		if (!parent_bus)
+			return -EPROBE_DEFER;
+	} else {
+		parent_bus_node = NULL;
+		parent_bus = mux_bus;
+	}
+
+	pb = xzalloc(sizeof(*pb));
+
+	pb->switch_data   = data;
+	pb->switch_fn     = switch_fn;
+	pb->current_child = -1;
+	pb->parent_id     = parent_count++;
+	pb->mii_bus       = parent_bus;
+
+	for_each_available_child_of_node(mux_node, child_bus_node) {
+		int v;
+
+		r = of_property_read_u32(child_bus_node, "reg", &v);
+		if (r) {
+			dev_err(dev,
+				"Error: Failed to find reg for child %pOF\n",
+				child_bus_node);
+			continue;
+		}
+
+		cb = xzalloc(sizeof(*cb));
+		cb->bus_number = v;
+		cb->parent     = pb;
+
+		cb->mii_bus.priv   = cb;
+		cb->mii_bus.parent = dev;
+		cb->mii_bus.read   = mdio_mux_read;
+		cb->mii_bus.write  = mdio_mux_write;
+		cb->mii_bus.dev.device_node = child_bus_node;
+
+		r = mdiobus_register(&cb->mii_bus);
+		if (r) {
+			dev_err(dev,
+				"Error: Failed to register MDIO bus for child %pOF\n",
+				child_bus_node);
+		}
+	}
+
+	parent_bus->is_multiplexed = true;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mdio_mux_init);
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 012b90e834..d209716a14 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -32,6 +32,9 @@ int mdiobus_detect(struct device_d *dev)
 	struct mii_bus *mii = to_mii_bus(dev);
 	int i, ret;
 
+	if (mii->is_multiplexed)
+		return 0;
+
 	for (i = 0; i < PHY_MAX_ADDR; i++) {
 		struct phy_device *phydev;
 
@@ -207,6 +210,33 @@ struct mii_bus *mdiobus_get_bus(int busnum)
 }
 
 /**
+ * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
+ * @mdio_bus_np: Pointer to the mii_bus.
+ *
+ * Returns a reference to the mii_bus, or NULL if none found.
+ *
+ * Because the association of a device_node and mii_bus is made via
+ * mdiobus_register(), the mii_bus cannot be found before it is
+ * registered with mdiobus_register().
+ *
+ */
+struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
+{
+	struct mii_bus *mii;
+
+	if (!mdio_bus_np)
+		return NULL;
+
+	for_each_mii_bus(mii)
+		if (mii->dev.device_node == mdio_bus_np)
+			return mii;
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_mdio_find_bus);
+
+
+/**
  * mdio_bus_match - determine if given PHY driver supports the given PHY device
  * @dev: target PHY device
  * @drv: given PHY driver