STRUCT QMP(9)

struct qmp(9) 💅

okay so this is from the Kernel API Manual, and we're about to get into the driver-state of it all. no cap, this struct is lowkey the main character. 🎀

🌸 NAME 🌸

struct qmp — driver state for QMP implementation. it's giving "everything the driver needs to keep its little life together," and honestly? obsessed. ✨

✨ SYNOPSIS ✨

struct qmp {
    void __iomem *msgram;
    struct device *dev;
    struct mbox_client mbox_client;
    struct mbox_chan *mbox_chan;
    size_t offset;
    size_t size;
    wait_queue_head_t event;
    struct mutex tx_lock;
    struct clk_hw qdss_clk;
    struct qmp_cooling_device *cooling_devs;
    struct dentry *debugfs_root;
    struct dentry *debugfs_files[QMP_DEBUGFS_FILES];
};

🫶 Members 🫶

• msgram — iomem referencing the message RAM used for communication. the message RAM is literally right there, bestie. 🫶
• dev — reference to QMP device. it's the device link-up, periodt. 💖
• mbox_client — mailbox client used to ring the doorbell on transmit. yes, we're ringing the doorbell, slay. 🔔
• mbox_chan — mailbox channel used to ring the doorbell on transmit. same doorbell energy, different field. 💅
• offset — offset within msgram where messages should be written. so this is where the writing goes down. ✍️
• size — maximum size of the messages to be transmitted. the literal size limit, no cap. 📏
• event — wait_queue for synchronization with the IRQ. IRQ sync moment, iconic. ⏳
• tx_lock — provides synchronization between multiple callers of qmp_send. multiple callers? not on this lock's watch. 🔒
• qdss_clk — QDSS clock hw struct. clock hardware representation, we love to see it. ⏰
• cooling_devs — thermal cooling devices. thermal cooling besties, assembled. 🧊
• debugfs_root — directory for the developer/tester interface. the developer/tester girlies have a home. 🏠
• debugfs_files — array of individual debugfs entries under debugfs_root. every entry is a little debugfs star. ⭐

👑 SEE ALSO 👑

Kernel file ./drivers/soc/qcom/qcom_aoss.c — meet qmp_send(9), qmp_get(9), and qmp_put(9). go read the friends, bestie, iykyk. 🦋🌈

source/version + date sign-off: this page comes from ./drivers/soc/qcom, dated October 2026, under the title struct qmp(9). that's the footer situation, and it ate. 💖🎀