STRUCT DVB_CA_EN50221(9)

💖 struct dvb_ca_en50221(9) 💖

Okay so this is the struct dvb_ca_en50221(9) page from the Kernel API Manual, and it is literally the struct that describes a CA interface. Bestie, it’s giving “here is every function pointer you need” and I’m obsessed. 🫶

✨ NAME ✨

struct dvb_ca_en50221 — Structure describing a CA interface. That’s the whole name section, no cap. 💅

🦋 SYNOPSIS 🦋

       struct dvb_ca_en50221 {
           struct module *owner;
           int (*read_attribute_mem)(struct dvb_ca_en50221 *ca, int slot, int
       address);
           int (*write_attribute_mem)(struct dvb_ca_en50221 *ca, int slot, int
       address, u8 value);
           int (*read_cam_control)(struct dvb_ca_en50221 *ca, int slot, u8
       address);
           int (*write_cam_control)(struct dvb_ca_en50221 *ca, int slot, u8
       address, u8 value);
           int (*read_data)(struct dvb_ca_en50221 *ca, int slot, u8 *ebuf, int
       ecount);
           int (*write_data)(struct dvb_ca_en50221 *ca, int slot, u8 *ebuf, int
       ecount);
           int (*slot_reset)(struct dvb_ca_en50221 *ca, int slot);
           int (*slot_shutdown)(struct dvb_ca_en50221 *ca, int slot);
           int (*slot_ts_enable)(struct dvb_ca_en50221 *ca, int slot);
           int (*poll_slot_status)(struct dvb_ca_en50221 *ca, int slot, int
       open);
           void *data;
           void *private;
        };

🎀 Members 🎀

Okay, member-by-member, because every single one matters. No skipping, no summarising, periodt. 🌸

• owner — the module owning this structure. Slay, it owns it. 👑
• read_attribute_mem — function for reading attribute memory on the CAM.
• write_attribute_mem — function for writing attribute memory on the CAM.
• read_cam_control — function for reading the control interface on the CAM.
• write_cam_control — the page says “function for reading the control interface on the CAM”, exactly like read_cam_control. Not me double-checking, I’m keeping the original wording, bestie. 😭
• read_data — function for reading data (block mode).
• write_data — function for writing data (block mode).
• slot_reset — function to reset the CAM slot.
• slot_shutdown — function to shutdown a CAM slot.
• slot_ts_enable — function to enable the Transport Stream on a CAM slot. 🔥
• poll_slot_status — function to poll slot status. Only necessary if DVB_CA_FLAG_EN50221_IRQ_CAMCHANGE is not set. ⭐
• data — private data, used by caller.
• private — Opaque data used by the dvb_ca core. Do not modify! 💀

⚠️ NOTE ⚠️

Vibe check, and this part is highkey important: the read_*, write_* and poll_slot_status functions will be called for different slots concurrently and need to use locks where and if appropriate. There will be no concurrent access to one slot. So lock where it makes sense, okay? 🧚

🌈 SEE ALSO 🌈

Go click these, iykyk:

• Kernel file ./include/media/dvb_ca_en50221.h
• dvb_ca_en50221_camchange_irq(9)
• dvb_ca_en50221_camready_irq(9)
• dvb_ca_en50221_frda_irq(9)
• dvb_ca_en50221_init(9)
• dvb_ca_en50221_release(9)

Source/version: ./include/media · date: October 2026 · page: struct dvb_ca_en50221(9) — okay bye bestie, go build something iconic 💜🌈