STRUCT PWRDM_OPS(9)

🦋 NAME 🦋

okay bestie, welcome to the Kernel API Manual ✨ this page is literally all about struct pwrdm_ops — the “Arch specific function implementations” situation 💅. It’s giving architecture-specific function pointers, and we’re gonna go through every single one, no skipping 🫶.

✨ SYNOPSIS ✨

Here’s the whole struct, bestie — look at all these function pointers being iconic 👑

struct pwrdm_ops {
    int (*pwrdm_set_next_pwrst)(struct powerdomain *pwrdm, u8 pwrst);
    int (*pwrdm_read_next_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_read_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_read_prev_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_set_logic_retst)(struct powerdomain *pwrdm, u8 pwrst);
    int (*pwrdm_set_mem_onst)(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
    int (*pwrdm_set_mem_retst)(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
    int (*pwrdm_read_logic_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_read_prev_logic_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_read_logic_retst)(struct powerdomain *pwrdm);
    int (*pwrdm_read_mem_pwrst)(struct powerdomain *pwrdm, u8 bank);
    int (*pwrdm_read_prev_mem_pwrst)(struct powerdomain *pwrdm, u8 bank);
    int (*pwrdm_read_mem_retst)(struct powerdomain *pwrdm, u8 bank);
    int (*pwrdm_clear_all_prev_pwrst)(struct powerdomain *pwrdm);
    int (*pwrdm_enable_hdwr_sar)(struct powerdomain *pwrdm);
    int (*pwrdm_disable_hdwr_sar)(struct powerdomain *pwrdm);
    int (*pwrdm_set_lowpwrstchange)(struct powerdomain *pwrdm);
    int (*pwrdm_wait_transition)(struct powerdomain *pwrdm);
    int (*pwrdm_has_voltdm)(void);
    void (*pwrdm_save_context)(struct powerdomain *pwrdm);
    void (*pwrdm_restore_context)(struct powerdomain *pwrdm);
};

🌸 Members 🌸

Each of these is a function pointer member, and here’s what the page says about it 💖:

• pwrdm_set_next_pwrst — set the target power state for a pd 🎯
• pwrdm_read_next_pwrst — read the target power state set for a pd 👀
• pwrdm_read_pwrst — read the current power state of a pd ✨
• pwrdm_read_prev_pwrst — read the prev power state entered by the pd 🕰️
• pwrdm_set_logic_retst — set the logic state in RET for a pd 🧠
• pwrdm_set_mem_onst — set the Memory state in ON for a pd 🔛
• pwrdm_set_mem_retst — set the Memory state in RET for a pd 💾
• pwrdm_read_logic_pwrst — read the current logic state of a pd 🧚
• pwrdm_read_prev_logic_pwrst — read the previous logic state entered by a pd 🌀
• pwrdm_read_logic_retst — read the logic state in RET for a pd 🌙
• pwrdm_read_mem_pwrst — read the current memory state of a pd 📖
• pwrdm_read_prev_mem_pwrst — read the previous memory state entered by a pd ⏪
• pwrdm_read_mem_retst — read the memory state in RET for a pd 💤
• pwrdm_clear_all_prev_pwrst — clear all previous power states logged for a pd 🧹
• pwrdm_enable_hdwr_sar — enable Hardware Save-Restore feature for the pd 🔥
• pwrdm_disable_hdwr_sar — disable Hardware Save-Restore feature for a pd 💀
• pwrdm_set_lowpwrstchange — enable pd transitions from a shallow to deep sleep 🛌
• pwrdm_wait_transition — wait for a pd state transition to complete ⏳
• pwrdm_has_voltdm — check if a voltdm association is needed 🔌

🔥 Description 🔥

Okay so here’s the tea about pwrdm_set_lowpwrstchange ☕: on the OMAP2 and 3-family chips, a powerdomain’s power state is not allowed to directly transition from one low-power state (e.g., CSWR) to another low-power state (e.g., OFF) without first waking up the powerdomain 😭. That literally wastes energy. So OMAP4 chips support the ability to transition a powerdomain power state directly from one low-power state to another ✨. The function pointed to by pwrdm_set_lowpwrstchange is intended to configure the OMAP4 hardware powerdomain state machine to enable this feature. Periodt 💅.

🌈 SEE ALSO 🌈

check out the kernel file ./arch/arm/mach-omap2/powerdomain.h and struct powerdomain(9) 🫶.

okay that’s the whole page, bestie 💖 this cutie comes from ./arch/arm/mach-omap2, and it’s the October 2026 edition of struct pwrdm_ops(9). go off, kernel queen 👑✨