[v2,2/3] netdev/of/phy: Add MDIO bus multiplexer support.

Message ID	1317166015-20714-3-git-send-email-david.daney@cavium.com
State	Changes Requested, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: David Daney <david.daney@cavium.com> To: devicetree-discuss@lists.ozlabs.org, grant.likely@secretlab.ca, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net Cc: David Daney <david.daney@cavium.com> Subject: [PATCH v2 2/3] netdev/of/phy: Add MDIO bus multiplexer support. Date: Tue, 27 Sep 2011 16:26:54 -0700 Message-Id: <1317166015-20714-3-git-send-email-david.daney@cavium.com> In-Reply-To: <1317166015-20714-1-git-send-email-david.daney@cavium.com> References: <1317166015-20714-1-git-send-email-david.daney@cavium.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk

On Tue, Sep 27, 2011 at 04:26:54PM -0700, David Daney wrote: > This patch adds a somewhat generic framework for MDIO bus > multiplexers. It is modeled on the I2C multiplexer. > > The multiplexer is needed if there are multiple PHYs with the same > address connected to the same MDIO bus adepter, or if there is > insufficient electrical drive capability for all the connected PHY > devices. > > Conceptually it could look something like this: > > ------------------ > | Control Signal | > --------+--------- > | > --------------- --------+------ > | MDIO MASTER |---| Multiplexer | > --------------- --+-------+---- > | | > C C > h h > i i > l l > d d > | | > --------- A B --------- > | | | | | | > | PHY@1 +-------+ +---+ PHY@1 | > | | | | | | > --------- | | --------- > --------- | | --------- > | | | | | | > | PHY@2 +-------+ +---+ PHY@2 | > | | | | > --------- --------- > > This framework configures the bus topology from device tree data. The > mechanics of switching the multiplexer is left to device specific > drivers. > > The follow-on patch contains a multiplexer driven by GPIO lines. > > Signed-off-by: David Daney <david.daney@cavium.com> > Acked-by: Andy Fleming <afleming@freescale.com> > Cc: Grant Likely <grant.likely@secretlab.ca> > Cc: "David S. Miller" <davem@davemloft.net> > --- > Documentation/devicetree/bindings/net/mdio-mux.txt | 136 +++++++++++++++ > drivers/net/phy/Kconfig | 8 + > drivers/net/phy/Makefile | 1 + > drivers/net/phy/mdio-mux.c | 182 ++++++++++++++++++++ > include/linux/mdio-mux.h | 18 ++ > 5 files changed, 345 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/net/mdio-mux.txt > create mode 100644 drivers/net/phy/mdio-mux.c > create mode 100644 include/linux/mdio-mux.h > > diff --git a/Documentation/devicetree/bindings/net/mdio-mux.txt b/Documentation/devicetree/bindings/net/mdio-mux.txt > new file mode 100644 > index 0000000..5acba65 > --- /dev/null > +++ b/Documentation/devicetree/bindings/net/mdio-mux.txt > @@ -0,0 +1,136 @@ > +Common MDIO bus multiplexer/switch properties. > + > +An MDIO bus multiplexer/switch will have several child busses that are > +numbered uniquely in a device dependent manner. The nodes for an MDIO > +bus multiplexer/switch will have one child node for each child bus. > + > +Required properties: > +- mdio-parent-bus : phandle to the parent MDIO bus. > +- #address-cells = <1>; > +- #size-cells = <0>; > + > +Optional properties: > +- Other properties specific to the multiplexer/switch hardware. > + > +Required properties for child nodes: > +- #address-cells = <1>; > +- #size-cells = <0>; > +- reg : The sub-bus number. > + > + > +Example : > + > + /* The parent MDIO bus. */ > + smi1: mdio@1180000001900 { > + compatible = "cavium,octeon-3860-mdio"; > + #address-cells = <1>; > + #size-cells = <0>; > + reg = <0x11800 0x00001900 0x0 0x40>; > + }; > + > + /* > + An NXP sn74cbtlv3253 dual 1-of-4 switch controlled by a > + pair of GPIO lines. Child busses 2 and 3 populated with 4 > + PHYs each. > + */ > + mdio-mux { > + compatible = "cavium,mdio-mux-sn74cbtlv3253", "cavium,mdio-mux"; > + gpios = <&gpio1 3 0>, <&gpio1 4 0>; > + mdio-parent-bus = <&smi1>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + mdio@2 { > + reg = <2>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + phy11: ethernet-phy@1 { > + reg = <1>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <10 8>; /* Pin 10, active low */ > + }; > + phy12: ethernet-phy@2 { > + reg = <2>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <10 8>; /* Pin 10, active low */ > + }; > + phy13: ethernet-phy@3 { > + reg = <3>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <10 8>; /* Pin 10, active low */ > + }; > + phy14: ethernet-phy@4 { > + reg = <4>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <10 8>; /* Pin 10, active low */ > + }; > + }; > + > + mdio@3 { > + reg = <3>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + phy21: ethernet-phy@1 { > + reg = <1>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <12 8>; /* Pin 12, active low */ > + }; > + phy22: ethernet-phy@2 { > + reg = <2>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <12 8>; /* Pin 12, active low */ > + }; > + phy23: ethernet-phy@3 { > + reg = <3>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <12 8>; /* Pin 12, active low */ > + }; > + phy24: ethernet-phy@4 { > + reg = <4>; > + compatible = "marvell,88e1149r"; > + marvell,reg-init = <3 0x10 0 0x5777>, > + <3 0x11 0 0x00aa>, > + <3 0x12 0 0x4105>, > + <3 0x13 0 0x0a60>; > + interrupt-parent = <&gpio>; > + interrupts = <12 8>; /* Pin 12, active low */ > + }; > + }; > + }; > diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig > index a702443..59848bc 100644 > --- a/drivers/net/phy/Kconfig > +++ b/drivers/net/phy/Kconfig > @@ -119,6 +119,14 @@ config MDIO_GPIO > To compile this driver as a module, choose M here: the module > will be called mdio-gpio. > > +config MDIO_BUS_MUX > + tristate "Support for MDIO bus multiplexers" > + 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. > + Don't make this a user visible option. Make the bus driver select it. > config MDIO_OCTEON > tristate "Support for MDIO buses on Octeon SOCs" > depends on CPU_CAVIUM_OCTEON > diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile > index 2333215..0c081d5 100644 > --- a/drivers/net/phy/Makefile > +++ b/drivers/net/phy/Makefile > @@ -23,3 +23,4 @@ obj-$(CONFIG_DP83640_PHY) += dp83640.o > obj-$(CONFIG_STE10XP) += ste10Xp.o > obj-$(CONFIG_MICREL_PHY) += micrel.o > obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o > +obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o > diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c > new file mode 100644 > index 0000000..a940296 > --- /dev/null > +++ b/drivers/net/phy/mdio-mux.c > @@ -0,0 +1,182 @@ > +/* > + * 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. > + * > + * Copyright (C) 2011 Cavium Networks > + */ > + > +#include <linux/platform_device.h> > +#include <linux/of_mdio.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/gfp.h> > +#include <linux/phy.h> > +#include <linux/mdio-mux.h> > + > +#define DRV_VERSION "1.0" > +#define DRV_DESCRIPTION "MDIO bus multiplexer driver" > + > +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; > + int bus_number; > + int phy_irq[PHY_MAX_ADDR]; > +}; > + > +/* > + * The parent bus' lock is used to order access to the switch_fn. > + */ > +static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum) > +{ > + struct mdio_mux_child_bus *cb = bus->priv; > + struct mdio_mux_parent_bus *pb = cb->parent; > + int r; > + > + mutex_lock(&pb->mii_bus->mdio_lock); > + r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data); > + if (r) > + goto out; > + > + pb->current_child = cb->bus_number; > + > + r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum); > +out: > + mutex_unlock(&pb->mii_bus->mdio_lock); > + > + return r; > +} > + > +/* > + * The parent bus' lock is used to order access to the switch_fn. > + */ > +static int mdio_mux_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; > + > + mutex_lock(&pb->mii_bus->mdio_lock); > + r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data); > + if (r) > + goto out; > + > + pb->current_child = cb->bus_number; > + > + r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val); > +out: > + mutex_unlock(&pb->mii_bus->mdio_lock); > + > + return r; > +} > + > +static int parent_count; > + > +int mdio_mux_probe(struct platform_device *pdev, > + int (*switch_fn)(int cur, int desired, void *data), > + void *data) > +{ Don't call this probe. Probe typically means top level driver, but this module is a library used by MDIO mux drivers. Call this functions something like init. Also, passing it a platform_device looks wrong since it might be a platform_device, but it might be an i2c_client or an spi_device. Pass in struct device instead. Also, this function should return the pointer to the allocated mdio_mux_parent_bus so that the calling driver has a reference to it. > + struct device_node *parent_bus_node; > + struct device_node *child_bus_node; > + int r, n, ret_val; > + struct mii_bus *parent_bus; > + struct mdio_mux_parent_bus *pb; > + struct mdio_mux_child_bus *cb; > + > + if (!pdev->dev.of_node) > + return -ENODEV; > + > + parent_bus_node = of_parse_phandle(pdev->dev.of_node, "mdio-parent-bus", 0); > + > + if (!parent_bus_node) > + return -ENODEV; > + > + parent_bus = of_mdio_find_bus(parent_bus_node); What if of_mdio_find_bus() fails? > + > + pb = devm_kzalloc(&pdev->dev, sizeof(*pb), GFP_KERNEL); > + if (pb == NULL) { > + ret_val = -ENOMEM; > + goto err_parent_bus; > + } > + > + pb->switch_data = data; > + pb->switch_fn = switch_fn; > + pb->current_child = -1; > + pb->parent_id = parent_count++; > + pb->mii_bus = parent_bus; > + > + n = 0; > + for_each_child_of_node(pdev->dev.of_node, child_bus_node) { > + u32 v; > + > + r = of_property_read_u32(child_bus_node, "reg", &v); > + if (r == 0) { > + cb = devm_kzalloc(&pdev->dev, sizeof(*cb), GFP_KERNEL); > + if (cb == NULL) > + break; > + cb->bus_number = v; > + cb->parent = pb; > + cb->mii_bus = mdiobus_alloc(); > + cb->mii_bus->priv = cb; > + > + cb->mii_bus->irq = cb->phy_irq; > + cb->mii_bus->name = "mdio_mux"; > + snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x", > + pb->parent_id, v); > + cb->mii_bus->parent = &pdev->dev; > + cb->mii_bus->read = mdio_mux_read; > + cb->mii_bus->write = mdio_mux_write; The parent bus should probably maintain a list of all child busses so that a shutdown function can tear it all down again. > + r = of_mdiobus_register(cb->mii_bus, child_bus_node); > + if (r) { > + of_node_put(child_bus_node); > + devm_kfree(&pdev->dev, cb); > + } else { > + n++; > + } > + > + } else { > + of_node_put(child_bus_node); > + } > + } > + if (n) { > + dev_info(&pdev->dev, "Version " DRV_VERSION "\n"); > + return 0; > + } > + ret_val = -ENOMEM; > + devm_kfree(&pdev->dev, pb); > +err_parent_bus: > + of_node_put(parent_bus_node); > + return ret_val; > +} > +EXPORT_SYMBOL(mdio_mux_probe); > + > +static int __devexit mdio_mux_remove(struct platform_device *pdev) > +{ > + return 0; > +} > + > +static int __init mdio_mux_mod_init(void) > +{ > + return 0; > +} > +module_init(mdio_mux_mod_init); > + > +static void __exit mdio_mux_mod_exit(void) > +{ > +} > +module_exit(mdio_mux_mod_exit); I don't believe that you need module empty module init/exit/remove routines. Just drop them. > + > +MODULE_DESCRIPTION(DRV_DESCRIPTION); > +MODULE_VERSION(DRV_VERSION); > +MODULE_AUTHOR("David Daney"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/mdio-mux.h b/include/linux/mdio-mux.h > new file mode 100644 > index 0000000..522992a > --- /dev/null > +++ b/include/linux/mdio-mux.h > @@ -0,0 +1,18 @@ > +/* > + * MDIO bus multiplexer framwork. > + * > + * 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. > + * > + * Copyright (C) 2011 Cavium Networks > + */ > +#ifndef __LINUX_MDIO_MUX_H > +#define __LINUX_MDIO_MUX_H > +#include <linux/platform_device.h> > + > +int mdio_mux_probe(struct platform_device *pdev, > + int (*switch_fn) (int cur, int desired, void *data), > + void *data); > + > +#endif /* __LINUX_MDIO_MUX_H */ > -- > 1.7.2.3 > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

diff --git a/Documentation/devicetree/bindings/net/mdio-mux.txt b/Documentation/devicetree/bindings/net/mdio-mux.txt new file mode 100644 index 0000000..5acba65 --- /dev/null +++ b/Documentation/devicetree/bindings/net/mdio-mux.txt @@ -0,0 +1,136 @@ +Common MDIO bus multiplexer/switch properties. + +An MDIO bus multiplexer/switch will have several child busses that are +numbered uniquely in a device dependent manner. The nodes for an MDIO +bus multiplexer/switch will have one child node for each child bus. + +Required properties: +- mdio-parent-bus : phandle to the parent MDIO bus. +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties: +- Other properties specific to the multiplexer/switch hardware. + +Required properties for child nodes: +- #address-cells = <1>; +- #size-cells = <0>; +- reg : The sub-bus number. + + +Example : + + /* The parent MDIO bus. */ + smi1: mdio@1180000001900 { + compatible = "cavium,octeon-3860-mdio"; + #address-cells = <1>; + #size-cells = <0>; + reg = <0x11800 0x00001900 0x0 0x40>; + }; + + /* + An NXP sn74cbtlv3253 dual 1-of-4 switch controlled by a + pair of GPIO lines. Child busses 2 and 3 populated with 4 + PHYs each. + */ + mdio-mux { + compatible = "cavium,mdio-mux-sn74cbtlv3253", "cavium,mdio-mux"; + gpios = <&gpio1 3 0>, <&gpio1 4 0>; + mdio-parent-bus = <&smi1>; + #address-cells = <1>; + #size-cells = <0>; + + mdio@2 { + reg = <2>; + #address-cells = <1>; + #size-cells = <0>; + + phy11: ethernet-phy@1 { + reg = <1>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <10 8>; /* Pin 10, active low */ + }; + phy12: ethernet-phy@2 { + reg = <2>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <10 8>; /* Pin 10, active low */ + }; + phy13: ethernet-phy@3 { + reg = <3>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <10 8>; /* Pin 10, active low */ + }; + phy14: ethernet-phy@4 { + reg = <4>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <10 8>; /* Pin 10, active low */ + }; + }; + + mdio@3 { + reg = <3>; + #address-cells = <1>; + #size-cells = <0>; + + phy21: ethernet-phy@1 { + reg = <1>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <12 8>; /* Pin 12, active low */ + }; + phy22: ethernet-phy@2 { + reg = <2>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <12 8>; /* Pin 12, active low */ + }; + phy23: ethernet-phy@3 { + reg = <3>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <12 8>; /* Pin 12, active low */ + }; + phy24: ethernet-phy@4 { + reg = <4>; + compatible = "marvell,88e1149r"; + marvell,reg-init = <3 0x10 0 0x5777>, + <3 0x11 0 0x00aa>, + <3 0x12 0 0x4105>, + <3 0x13 0 0x0a60>; + interrupt-parent = <&gpio>; + interrupts = <12 8>; /* Pin 12, active low */ + }; + }; + }; diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index a702443..59848bc 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -119,6 +119,14 @@ config MDIO_GPIO To compile this driver as a module, choose M here: the module will be called mdio-gpio. +config MDIO_BUS_MUX + tristate "Support for MDIO bus multiplexers" + 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_OCTEON tristate "Support for MDIO buses on Octeon SOCs" depends on CPU_CAVIUM_OCTEON diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile index 2333215..0c081d5 100644 --- a/drivers/net/phy/Makefile +++ b/drivers/net/phy/Makefile @@ -23,3 +23,4 @@ obj-$(CONFIG_DP83640_PHY) += dp83640.o obj-$(CONFIG_STE10XP) += ste10Xp.o obj-$(CONFIG_MICREL_PHY) += micrel.o obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o +obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c new file mode 100644 index 0000000..a940296 --- /dev/null +++ b/drivers/net/phy/mdio-mux.c @@ -0,0 +1,182 @@ +/* + * 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. + * + * Copyright (C) 2011 Cavium Networks + */ + +#include <linux/platform_device.h> +#include <linux/of_mdio.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/gfp.h> +#include <linux/phy.h> +#include <linux/mdio-mux.h> + +#define DRV_VERSION "1.0" +#define DRV_DESCRIPTION "MDIO bus multiplexer driver" + +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; + int bus_number; + int phy_irq[PHY_MAX_ADDR]; +}; + +/* + * The parent bus' lock is used to order access to the switch_fn. + */ +static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum) +{ + struct mdio_mux_child_bus *cb = bus->priv; + struct mdio_mux_parent_bus *pb = cb->parent; + int r; + + mutex_lock(&pb->mii_bus->mdio_lock); + r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data); + if (r) + goto out; + + pb->current_child = cb->bus_number; + + r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum); +out: + mutex_unlock(&pb->mii_bus->mdio_lock); + + return r; +} + +/* + * The parent bus' lock is used to order access to the switch_fn. + */ +static int mdio_mux_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; + + mutex_lock(&pb->mii_bus->mdio_lock); + r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data); + if (r) + goto out; + + pb->current_child = cb->bus_number; + + r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val); +out: + mutex_unlock(&pb->mii_bus->mdio_lock); + + return r; +} + +static int parent_count; + +int mdio_mux_probe(struct platform_device *pdev, + int (*switch_fn)(int cur, int desired, void *data), + void *data) +{ + struct device_node *parent_bus_node; + struct device_node *child_bus_node; + int r, n, ret_val; + struct mii_bus *parent_bus; + struct mdio_mux_parent_bus *pb; + struct mdio_mux_child_bus *cb; + + if (!pdev->dev.of_node) + return -ENODEV; + + parent_bus_node = of_parse_phandle(pdev->dev.of_node, "mdio-parent-bus", 0); + + if (!parent_bus_node) + return -ENODEV; + + parent_bus = of_mdio_find_bus(parent_bus_node); + + pb = devm_kzalloc(&pdev->dev, sizeof(*pb), GFP_KERNEL); + if (pb == NULL) { + ret_val = -ENOMEM; + goto err_parent_bus; + } + + pb->switch_data = data; + pb->switch_fn = switch_fn; + pb->current_child = -1; + pb->parent_id = parent_count++; + pb->mii_bus = parent_bus; + + n = 0; + for_each_child_of_node(pdev->dev.of_node, child_bus_node) { + u32 v; + + r = of_property_read_u32(child_bus_node, "reg", &v); + if (r == 0) { + cb = devm_kzalloc(&pdev->dev, sizeof(*cb), GFP_KERNEL); + if (cb == NULL) + break; + cb->bus_number = v; + cb->parent = pb; + cb->mii_bus = mdiobus_alloc(); + cb->mii_bus->priv = cb; + + cb->mii_bus->irq = cb->phy_irq; + cb->mii_bus->name = "mdio_mux"; + snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x", + pb->parent_id, v); + cb->mii_bus->parent = &pdev->dev; + cb->mii_bus->read = mdio_mux_read; + cb->mii_bus->write = mdio_mux_write; + r = of_mdiobus_register(cb->mii_bus, child_bus_node); + if (r) { + of_node_put(child_bus_node); + devm_kfree(&pdev->dev, cb); + } else { + n++; + } + + } else { + of_node_put(child_bus_node); + } + } + if (n) { + dev_info(&pdev->dev, "Version " DRV_VERSION "\n"); + return 0; + } + ret_val = -ENOMEM; + devm_kfree(&pdev->dev, pb); +err_parent_bus: + of_node_put(parent_bus_node); + return ret_val; +} +EXPORT_SYMBOL(mdio_mux_probe); + +static int __devexit mdio_mux_remove(struct platform_device *pdev) +{ + return 0; +} + +static int __init mdio_mux_mod_init(void) +{ + return 0; +} +module_init(mdio_mux_mod_init); + +static void __exit mdio_mux_mod_exit(void) +{ +} +module_exit(mdio_mux_mod_exit); + +MODULE_DESCRIPTION(DRV_DESCRIPTION); +MODULE_VERSION(DRV_VERSION); +MODULE_AUTHOR("David Daney"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mdio-mux.h b/include/linux/mdio-mux.h new file mode 100644 index 0000000..522992a --- /dev/null +++ b/include/linux/mdio-mux.h @@ -0,0 +1,18 @@ +/* + * MDIO bus multiplexer framwork. + * + * 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. + * + * Copyright (C) 2011 Cavium Networks + */ +#ifndef __LINUX_MDIO_MUX_H +#define __LINUX_MDIO_MUX_H +#include <linux/platform_device.h> + +int mdio_mux_probe(struct platform_device *pdev, + int (*switch_fn) (int cur, int desired, void *data), + void *data); + +#endif /* __LINUX_MDIO_MUX_H */

[v2,2/3] netdev/of/phy: Add MDIO bus multiplexer support.

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