STRUCT FSL_ESAI(9)

💜 struct fsl_esai(9) — like, the whole vibe

okay so bestie, this is a page straight out of the Kernel API Manual — it's the manpage for struct fsl_esai(9), and no cap, it's just the private data blob for the ESAI driver. think of it as the driver's little purse where it keeps literally everything it needs 👜✨

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🌸 NAME 🌸

struct fsl_esai — ESAI private data. that's it, that's the whole name. it's the driver's personal stash of state, and we're about to open it up 🎀

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✨ SYNOPSIS ✨

here's the whole struct, character for character, don't touch it, she's perfect:

struct fsl_esai {
    struct snd_dmaengine_dai_dma_data dma_params_rx;
    struct snd_dmaengine_dai_dma_data dma_params_tx;
    struct platform_device *pdev;
    struct regmap *regmap;
    struct clk *coreclk;
    struct clk *extalclk;
    struct clk *fsysclk;
    struct clk *spbaclk;
    struct work_struct work;
    const struct fsl_esai_soc_data *soc;
    spinlock_t lock;
    u32 fifo_depth;
    u32 slot_width;
    u32 slots;
    u32 tx_mask;
    u32 rx_mask;
    u32 channels[2];
    u32 hck_rate[2];
    u32 sck_rate[2];
    bool hck_dir[2];
    bool sck_div[2];
    bool consumer_mode;
    bool synchronous;
    char name[32];
 };

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🦋 MEMBERS 🦋

okay, member-by-member tour, let's go — each one gets its moment 💅

• dma_params_rx — DMA parameters for the receive channel 📥
• dma_params_tx — DMA parameters for the transmit channel 📤
• pdev — platform device pointer, the classic
• regmap — the regmap handler, aka how we poke registers
• coreclk — clock source to access the register 🔑
• extalclk — esai clock source, used to derive HCK, SCK and FS
• fsysclk — system clock source, also used to derive HCK, SCK and FS
• spbaclk — SPBA clock (optional, depending on SoC design — so, like, sometimes she shows up) 🙈
• work — work to handle the reset operation 🔁
• soc — soc specific data, the per-SoC lore
• lock — spin lock between hw_reset and trigger 🔒
• fifo_depth — depth of tx/rx FIFO
• slot_width — width of each DAI slot 📏
• slots — number of slots
• tx_mask — slot mask for TX
• rx_mask — slot mask for RX
• channels — channel num for tx or rx
• hck_rate — clock rate of desired HCKx clock ⏱️
• sck_rate — clock rate of desired SCKx clock ⏱️
• hck_dir — the direction of HCKx pads ➡️
• sck_div — if using PSR/PM dividers for SCKx clock
• consumer_mode — if fully using DAI clock consumer mode 👑
• synchronous — if using tx/rx synchronous mode
• name — driver name, the last of the bunch 🏷️

heads up bestie: quite a few of these are arrays with a [2] — channels, hck_rate, sck_rate, hck_dir, sck_div — so it's giving "one for tx, one for rx" energy. that's exactly how the original wrote them, so keep the brackets exactly as-is 💖

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🌈 SEE ALSO 🌈

go read these next, they're the supporting cast and they ate:

• Kernel file ./sound/soc/fsl/fsl_esai.c
• struct fsl_esai_soc_data(9)
• fsl_esai_divisor_cal(9)
• fsl_esai_set_dai_sysclk(9)
• fsl_esai_set_bclk(9)

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and that's the whole page, bestie, you understood it, periodt 💅✨

this little love letter lives in ./sound/soc/fsl, dated October 2026, and it's filed under struct fsl_esai(9) in the Kernel API Manual — mwah, go forth and derive those clocks 🎀🫶💜