STRUCT APPLE_ATCPHY(9)

💅 struct apple_atcphy(9)

okay so this is a page from the Kernel API Manual and it's literally all about struct apple_atcphy — the Apple Type-C PHY device struct. yes bestie, the whole page is one struct. and she's a big one. let's get into it 🫶

---

✨ NAME ✨

struct apple_atcphy — the Apple Type-C PHY device struct. that's it, that's the vibe. iconic behavior tbh 👑

---

🌸 SYNOPSIS 🌸

struct apple_atcphy {
    struct device_node *np;
    struct device *dev;
    struct {
      struct apple_tunable *axi2af;
      struct apple_tunable *common[2];
      struct apple_tunable *lane_usb3[2];
      struct apple_tunable *lane_dp[2];
      struct apple_tunable *lane_usb4[2];
    } tunables;
    enum atcphy_mode mode;
    bool swap_lanes;
    int dp_link_rate;
    bool pipehandler_up;
    struct {
      void __iomem *core;
      void __iomem *axi2af;
      void __iomem *usb2phy;
      void __iomem *pipehandler;
      void __iomem *lpdptx;
    } regs;
    struct {
      struct resource *core;
      struct resource *axi2af;
    } res;
    struct {
      struct phy *usb2;
      struct phy *usb3;
      struct phy *dp;
    } phys;
    struct phy_provider *phy_provider;
    struct reset_controller_dev rcdev;
    struct mutex lock;
 };

like. look at her. nested structs for days. we love a structured queen 💖

---

🎀 Members 🎀

time for the member-by-member vibe check, no skips, no cuts, fr fr:

• np — Device node pointer
• dev — Device pointer
• tunables — Firmware-provided tunable parameters
• tunables.axi2af — AXI to AF interface tunables
• tunables.common — Common tunables for all lanes
• tunables.lane_usb3 — USB3 lane-specific tunables
• tunables.lane_dp — DisplayPort lane-specific tunables
• tunables.lane_usb4 — USB4 lane-specific tunables
• mode — Current PHY operating mode
• swap_lanes — True if lanes must be swapped due to cable orientation
• dp_link_rate — DisplayPort link rate
• pipehandler_up — True if the PIPE mux ("pipehandler") is set to USB3 or USB4 mode
• regs — Memory-mapped registers
• regs.core — Core registers
• regs.axi2af — AXI to Apple Fabric interface registers
• regs.usb2phy — USB2 PHY registers
• regs.pipehandler — USB3 PIPE interface ("pipehandler") registers
• regs.lpdptx — DisplayPort registers
• res — Resources for memory-mapped registers, used to verify that tunables aren't out of bounds
• res.core — Core register resource
• res.axi2af — AXI to Apple Fabric interface resource
• phys — PHY instances
• phys.usb2 — USB2 PHY instance
• phys.usb3 — USB3 PHY instance
• phys.dp — DisplayPort PHY instance
• phy_provider — PHY provider instance
• rcdev — Reset controller device
• lock — Mutex for synchronizing register access across PHY, Type-C switch/mux and reset controller

bestie note: that lock mutex is doing the Lord's work — it keeps register access in sync across the PHY, the Type-C switch/mux and the reset controller. three whole worlds, one mutex. main character energy for real 😭

---

🔥 SEE ALSO 🔥

go touch grass in the kernel source, iykyk:

• Kernel file ./drivers/phy/apple/atc.c
• enum atcphy_pipehandler_state(9)
• enum atcphy_mode(9)

---

and that's the page!! 💜 this lovely little manual lives at ./drivers/phy/apple, dated October 2026, and it's from the Kernel API Manual. bye bestie, go read atc.c 🦋✨🎀