STRUCT PWM_CHIP(9)

💖 struct pwm_chip(9) — or, like, the whole vibe of a PWM controller in one struct 💖

okay so this is a page from the Kernel API Manual, bestie, and it's all about struct pwm_chip — the literal main character that abstracts a PWM controller. no cap, this is the blueprint. let's get into it 🎀

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✨ NAME ✨

struct pwm_chip — abstract a PWM controller

like… it is the PWM controller, conceptually. the abstracted truth of it. 💅

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🌸 SYNOPSIS 🌸

struct pwm_chip {
    struct device dev;
    struct cdev cdev;
    const struct pwm_ops *ops;
    struct module *owner;
    unsigned int id;
    unsigned int npwm;
    struct pwm_device * (*of_xlate)(struct pwm_chip *chip, const struct of_phandle_args *args);
    bool atomic;
    struct gpio_chip gpio;
    bool uses_pwmchip_alloc;
    bool operational;
    union {
      struct mutex nonatomic_lock;
      spinlock_t atomic_lock;
    };
    struct pwm_device pwms[];
 };

okay look at her. gorgeous. every field hand-picked. ✨

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🦋 Members 🦋

bestie, this is the field-by-field tour, and yes we're doing all of them, because every single one matters:

• dev — the device providing the PWMs. the actual hardware parent, basically. 👑
• cdev — the struct cdev for this device.
• ops — the callbacks for this PWM controller. this is where the driver's behaviour lives, iykyk.
• owner — the module providing this chip. gotta know who's responsible. 💀
• id — the unique number of this PWM chip. her little ID card. 🎀
• npwm — number of PWMs controlled by this chip. the headcount. 🔥
• of_xlate — request a PWM device given a device tree PWM specifier. device-tree translation duty, very demure, very mindful.
• atomic — can the driver's ->apply be called in atomic context. big question, answer carefully. ⚡
• gpio — struct gpio_chip to operate this PWM chip's lines as GPO.
• uses_pwmchip_alloc — signals if pwmchip_allow was used to allocate this chip.
• operational — signals if the chip can be used (or is already deregistered). vibe check: passed or deregistered, no in-between. 🌈
• {unnamed_union} — anonymous. yes, it's just vibes. no name. 🙈
  • nonatomic_lock — mutex for nonatomic chips.
  • atomic_lock — mutex for atomic chips.
• pwms — array of PWM devices allocated by the framework. the flexible array member, the icon, the finale. ⭐

heads up: nonatomic_lock and atomic_lock live in the same anonymous union, so they're two flavours of the same slot — one for nonatomic chips, one for atomic chips. pick your fighter. 💅

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🧚 SEE ALSO 🧚

literally the whole friend group, go read these next (Kernel file ./include/linux/pwm.h):

• enum pwm_polarity(9)
• struct pwm_args(9)
• struct pwm_waveform(9)
• struct pwm_device(9)
• pwm_get_state(9)
• pwm_init_state(9)
• pwm_get_relative_duty_cycle(9)
• pwm_set_relative_duty_cycle(9)
• struct pwm_capture(9)
• struct pwm_ops(9)
• pwmchip_supports_waveform(9)
• pwm_config(9)
• pwm_enable(9)
• pwm_disable(9)
• pwm_might_sleep(9)

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and that's the whole page, bestie — no skips, no cuts, every field accounted for. 💜

okay so this was brought to you by ./include/linux, dated October 2026, filed lovingly under struct pwm_chip(9). periodt. 🫶💖