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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/driver-api/phy
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'Documentation/driver-api/phy')
-rw-r--r--Documentation/driver-api/phy/index.rst18
-rw-r--r--Documentation/driver-api/phy/phy.rst220
-rw-r--r--Documentation/driver-api/phy/samsung-usb2.rst137
3 files changed, 375 insertions, 0 deletions
diff --git a/Documentation/driver-api/phy/index.rst b/Documentation/driver-api/phy/index.rst
new file mode 100644
index 000000000..69ba1216d
--- /dev/null
+++ b/Documentation/driver-api/phy/index.rst
@@ -0,0 +1,18 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+Generic PHY Framework
+=====================
+
+.. toctree::
+
+ phy
+ samsung-usb2
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
+
diff --git a/Documentation/driver-api/phy/phy.rst b/Documentation/driver-api/phy/phy.rst
new file mode 100644
index 000000000..8e8b3e8f9
--- /dev/null
+++ b/Documentation/driver-api/phy/phy.rst
@@ -0,0 +1,220 @@
+=============
+PHY subsystem
+=============
+
+:Author: Kishon Vijay Abraham I <kishon@ti.com>
+
+This document explains the Generic PHY Framework along with the APIs provided,
+and how-to-use.
+
+Introduction
+============
+
+*PHY* is the abbreviation for physical layer. It is used to connect a device
+to the physical medium e.g., the USB controller has a PHY to provide functions
+such as serialization, de-serialization, encoding, decoding and is responsible
+for obtaining the required data transmission rate. Note that some USB
+controllers have PHY functionality embedded into it and others use an external
+PHY. Other peripherals that use PHY include Wireless LAN, Ethernet,
+SATA etc.
+
+The intention of creating this framework is to bring the PHY drivers spread
+all over the Linux kernel to drivers/phy to increase code re-use and for
+better code maintainability.
+
+This framework will be of use only to devices that use external PHY (PHY
+functionality is not embedded within the controller).
+
+Registering/Unregistering the PHY provider
+==========================================
+
+PHY provider refers to an entity that implements one or more PHY instances.
+For the simple case where the PHY provider implements only a single instance of
+the PHY, the framework provides its own implementation of of_xlate in
+of_phy_simple_xlate. If the PHY provider implements multiple instances, it
+should provide its own implementation of of_xlate. of_xlate is used only for
+dt boot case.
+
+::
+
+ #define of_phy_provider_register(dev, xlate) \
+ __of_phy_provider_register((dev), NULL, THIS_MODULE, (xlate))
+
+ #define devm_of_phy_provider_register(dev, xlate) \
+ __devm_of_phy_provider_register((dev), NULL, THIS_MODULE,
+ (xlate))
+
+of_phy_provider_register and devm_of_phy_provider_register macros can be used to
+register the phy_provider and it takes device and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the above
+2 macros to register the PHY provider.
+
+Often the device tree nodes associated with a PHY provider will contain a set
+of children that each represent a single PHY. Some bindings may nest the child
+nodes within extra levels for context and extensibility, in which case the low
+level of_phy_provider_register_full() and devm_of_phy_provider_register_full()
+macros can be used to override the node containing the children.
+
+::
+
+ #define of_phy_provider_register_full(dev, children, xlate) \
+ __of_phy_provider_register(dev, children, THIS_MODULE, xlate)
+
+ #define devm_of_phy_provider_register_full(dev, children, xlate) \
+ __devm_of_phy_provider_register_full(dev, children,
+ THIS_MODULE, xlate)
+
+ void devm_of_phy_provider_unregister(struct device *dev,
+ struct phy_provider *phy_provider);
+ void of_phy_provider_unregister(struct phy_provider *phy_provider);
+
+devm_of_phy_provider_unregister and of_phy_provider_unregister can be used to
+unregister the PHY.
+
+Creating the PHY
+================
+
+The PHY driver should create the PHY in order for other peripheral controllers
+to make use of it. The PHY framework provides 2 APIs to create the PHY.
+
+::
+
+ struct phy *phy_create(struct device *dev, struct device_node *node,
+ const struct phy_ops *ops);
+ struct phy *devm_phy_create(struct device *dev,
+ struct device_node *node,
+ const struct phy_ops *ops);
+
+The PHY drivers can use one of the above 2 APIs to create the PHY by passing
+the device pointer and phy ops.
+phy_ops is a set of function pointers for performing PHY operations such as
+init, exit, power_on and power_off.
+
+Inorder to dereference the private data (in phy_ops), the phy provider driver
+can use phy_set_drvdata() after creating the PHY and use phy_get_drvdata() in
+phy_ops to get back the private data.
+
+Getting a reference to the PHY
+==============================
+
+Before the controller can make use of the PHY, it has to get a reference to
+it. This framework provides the following APIs to get a reference to the PHY.
+
+::
+
+ struct phy *phy_get(struct device *dev, const char *string);
+ struct phy *phy_optional_get(struct device *dev, const char *string);
+ struct phy *devm_phy_get(struct device *dev, const char *string);
+ struct phy *devm_phy_optional_get(struct device *dev,
+ const char *string);
+ struct phy *devm_of_phy_get_by_index(struct device *dev,
+ struct device_node *np,
+ int index);
+
+phy_get, phy_optional_get, devm_phy_get and devm_phy_optional_get can
+be used to get the PHY. In the case of dt boot, the string arguments
+should contain the phy name as given in the dt data and in the case of
+non-dt boot, it should contain the label of the PHY. The two
+devm_phy_get associates the device with the PHY using devres on
+successful PHY get. On driver detach, release function is invoked on
+the devres data and devres data is freed. phy_optional_get and
+devm_phy_optional_get should be used when the phy is optional. These
+two functions will never return -ENODEV, but instead returns NULL when
+the phy cannot be found.Some generic drivers, such as ehci, may use multiple
+phys and for such drivers referencing phy(s) by name(s) does not make sense. In
+this case, devm_of_phy_get_by_index can be used to get a phy reference based on
+the index.
+
+It should be noted that NULL is a valid phy reference. All phy
+consumer calls on the NULL phy become NOPs. That is the release calls,
+the phy_init() and phy_exit() calls, and phy_power_on() and
+phy_power_off() calls are all NOP when applied to a NULL phy. The NULL
+phy is useful in devices for handling optional phy devices.
+
+Order of API calls
+==================
+
+The general order of calls should be::
+
+ [devm_][of_]phy_get()
+ phy_init()
+ phy_power_on()
+ [phy_set_mode[_ext]()]
+ ...
+ phy_power_off()
+ phy_exit()
+ [[of_]phy_put()]
+
+Some PHY drivers may not implement :c:func:`phy_init` or :c:func:`phy_power_on`,
+but controllers should always call these functions to be compatible with other
+PHYs. Some PHYs may require :c:func:`phy_set_mode <phy_set_mode_ext>`, while
+others may use a default mode (typically configured via devicetree or other
+firmware). For compatibility, you should always call this function if you know
+what mode you will be using. Generally, this function should be called after
+:c:func:`phy_power_on`, although some PHY drivers may allow it at any time.
+
+Releasing a reference to the PHY
+================================
+
+When the controller no longer needs the PHY, it has to release the reference
+to the PHY it has obtained using the APIs mentioned in the above section. The
+PHY framework provides 2 APIs to release a reference to the PHY.
+
+::
+
+ void phy_put(struct phy *phy);
+ void devm_phy_put(struct device *dev, struct phy *phy);
+
+Both these APIs are used to release a reference to the PHY and devm_phy_put
+destroys the devres associated with this PHY.
+
+Destroying the PHY
+==================
+
+When the driver that created the PHY is unloaded, it should destroy the PHY it
+created using one of the following 2 APIs::
+
+ void phy_destroy(struct phy *phy);
+ void devm_phy_destroy(struct device *dev, struct phy *phy);
+
+Both these APIs destroy the PHY and devm_phy_destroy destroys the devres
+associated with this PHY.
+
+PM Runtime
+==========
+
+This subsystem is pm runtime enabled. So while creating the PHY,
+pm_runtime_enable of the phy device created by this subsystem is called and
+while destroying the PHY, pm_runtime_disable is called. Note that the phy
+device created by this subsystem will be a child of the device that calls
+phy_create (PHY provider device).
+
+So pm_runtime_get_sync of the phy_device created by this subsystem will invoke
+pm_runtime_get_sync of PHY provider device because of parent-child relationship.
+It should also be noted that phy_power_on and phy_power_off performs
+phy_pm_runtime_get_sync and phy_pm_runtime_put respectively.
+There are exported APIs like phy_pm_runtime_get, phy_pm_runtime_get_sync,
+phy_pm_runtime_put, phy_pm_runtime_put_sync, phy_pm_runtime_allow and
+phy_pm_runtime_forbid for performing PM operations.
+
+PHY Mappings
+============
+
+In order to get reference to a PHY without help from DeviceTree, the framework
+offers lookups which can be compared to clkdev that allow clk structures to be
+bound to devices. A lookup can be made during runtime when a handle to the
+struct phy already exists.
+
+The framework offers the following API for registering and unregistering the
+lookups::
+
+ int phy_create_lookup(struct phy *phy, const char *con_id,
+ const char *dev_id);
+ void phy_remove_lookup(struct phy *phy, const char *con_id,
+ const char *dev_id);
+
+DeviceTree Binding
+==================
+
+The documentation for PHY dt binding can be found @
+Documentation/devicetree/bindings/phy/phy-bindings.txt
diff --git a/Documentation/driver-api/phy/samsung-usb2.rst b/Documentation/driver-api/phy/samsung-usb2.rst
new file mode 100644
index 000000000..c48c8b979
--- /dev/null
+++ b/Documentation/driver-api/phy/samsung-usb2.rst
@@ -0,0 +1,137 @@
+====================================
+Samsung USB 2.0 PHY adaptation layer
+====================================
+
+1. Description
+--------------
+
+The architecture of the USB 2.0 PHY module in Samsung SoCs is similar
+among many SoCs. In spite of the similarities it proved difficult to
+create a one driver that would fit all these PHY controllers. Often
+the differences were minor and were found in particular bits of the
+registers of the PHY. In some rare cases the order of register writes or
+the PHY powering up process had to be altered. This adaptation layer is
+a compromise between having separate drivers and having a single driver
+with added support for many special cases.
+
+2. Files description
+--------------------
+
+- phy-samsung-usb2.c
+ This is the main file of the adaptation layer. This file contains
+ the probe function and provides two callbacks to the Generic PHY
+ Framework. This two callbacks are used to power on and power off the
+ phy. They carry out the common work that has to be done on all version
+ of the PHY module. Depending on which SoC was chosen they execute SoC
+ specific callbacks. The specific SoC version is selected by choosing
+ the appropriate compatible string. In addition, this file contains
+ struct of_device_id definitions for particular SoCs.
+
+- phy-samsung-usb2.h
+ This is the include file. It declares the structures used by this
+ driver. In addition it should contain extern declarations for
+ structures that describe particular SoCs.
+
+3. Supporting SoCs
+------------------
+
+To support a new SoC a new file should be added to the drivers/phy
+directory. Each SoC's configuration is stored in an instance of the
+struct samsung_usb2_phy_config::
+
+ struct samsung_usb2_phy_config {
+ const struct samsung_usb2_common_phy *phys;
+ int (*rate_to_clk)(unsigned long, u32 *);
+ unsigned int num_phys;
+ bool has_mode_switch;
+ };
+
+The num_phys is the number of phys handled by the driver. `*phys` is an
+array that contains the configuration for each phy. The has_mode_switch
+property is a boolean flag that determines whether the SoC has USB host
+and device on a single pair of pins. If so, a special register has to
+be modified to change the internal routing of these pins between a USB
+device or host module.
+
+For example the configuration for Exynos 4210 is following::
+
+ const struct samsung_usb2_phy_config exynos4210_usb2_phy_config = {
+ .has_mode_switch = 0,
+ .num_phys = EXYNOS4210_NUM_PHYS,
+ .phys = exynos4210_phys,
+ .rate_to_clk = exynos4210_rate_to_clk,
+ }
+
+- `int (*rate_to_clk)(unsigned long, u32 *)`
+
+ The rate_to_clk callback is to convert the rate of the clock
+ used as the reference clock for the PHY module to the value
+ that should be written in the hardware register.
+
+The exynos4210_phys configuration array is as follows::
+
+ static const struct samsung_usb2_common_phy exynos4210_phys[] = {
+ {
+ .label = "device",
+ .id = EXYNOS4210_DEVICE,
+ .power_on = exynos4210_power_on,
+ .power_off = exynos4210_power_off,
+ },
+ {
+ .label = "host",
+ .id = EXYNOS4210_HOST,
+ .power_on = exynos4210_power_on,
+ .power_off = exynos4210_power_off,
+ },
+ {
+ .label = "hsic0",
+ .id = EXYNOS4210_HSIC0,
+ .power_on = exynos4210_power_on,
+ .power_off = exynos4210_power_off,
+ },
+ {
+ .label = "hsic1",
+ .id = EXYNOS4210_HSIC1,
+ .power_on = exynos4210_power_on,
+ .power_off = exynos4210_power_off,
+ },
+ {},
+ };
+
+- `int (*power_on)(struct samsung_usb2_phy_instance *);`
+ `int (*power_off)(struct samsung_usb2_phy_instance *);`
+
+ These two callbacks are used to power on and power off the phy
+ by modifying appropriate registers.
+
+Final change to the driver is adding appropriate compatible value to the
+phy-samsung-usb2.c file. In case of Exynos 4210 the following lines were
+added to the struct of_device_id samsung_usb2_phy_of_match[] array::
+
+ #ifdef CONFIG_PHY_EXYNOS4210_USB2
+ {
+ .compatible = "samsung,exynos4210-usb2-phy",
+ .data = &exynos4210_usb2_phy_config,
+ },
+ #endif
+
+To add further flexibility to the driver the Kconfig file enables to
+include support for selected SoCs in the compiled driver. The Kconfig
+entry for Exynos 4210 is following::
+
+ config PHY_EXYNOS4210_USB2
+ bool "Support for Exynos 4210"
+ depends on PHY_SAMSUNG_USB2
+ depends on CPU_EXYNOS4210
+ help
+ Enable USB PHY support for Exynos 4210. This option requires that
+ Samsung USB 2.0 PHY driver is enabled and means that support for this
+ particular SoC is compiled in the driver. In case of Exynos 4210 four
+ phys are available - device, host, HSCI0 and HSCI1.
+
+The newly created file that supports the new SoC has to be also added to the
+Makefile. In case of Exynos 4210 the added line is following::
+
+ obj-$(CONFIG_PHY_EXYNOS4210_USB2) += phy-exynos4210-usb2.o
+
+After completing these steps the support for the new SoC should be ready.