psc_i2s_set_sysclk(9)

💖 psc_i2s_set_sysclk — like, the whole kernel API manual vibe 💖

okay so bestie, you're reading the psc_i2s_set_sysclk(9) page from the Kernel API Manual and honestly? it's short, it's sweet, and it's giving "one job, done right" energy. let's get into it 🎀

---

✨ NAME ✨

psc_i2s_set_sysclk — set the clock frequency and direction. that's it. that's the whole thing. slay 💅

---

✨ SYNOPSIS ✨

int psc_i2s_set_sysclk (struct snd_soc_dai *cpu_dai , int clk_id ,
unsigned int freq , int dir );

so it's an int-returning function, four args, all listed above — screenshot that, it's iconic 📸

---

✨ ARGUMENTS ✨

• cpu_dai — the DAI runtime data pointer. it's the whole context for what you're poking at, so like… give it the respect it deserves 💖
• clk_id — reserved, should be zero. that means be a good citizen and pass 0, no cap 🙏
• freq — the frequency of the given clock ID… and currently it's ignored. yes bestie, it's a decorative argument rn, she's just standing there being pretty 🌸
• dir — either SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master). those are the two vibes ⭐

---

✨ DESCRIPTION ✨

so this function is called by the machine driver to tell us what the clock frequency and direction are. that's the whole point of her existence ✨

but here's the tea 🍓: currently we only support operating as a clock slave — that's SND_SOC_CLOCK_IN. and we genuinely don't care about the frequency, like at all, lowkey irrelevant. so if you roll up with a dir that is not SND_SOC_CLOCK_IN, she's gonna return an error at you. respectfully. 🫶

ngl the vibe check here is strict: SND_SOC_CLOCK_IN or nothing. clock master energy is not accepted in this house 💀

---

✨ RETURN ✨

• 0 on success 🎉
• -EINVAL on failure 😭

that's the whole menu, bestie, two options only.

---

✨ SEE ALSO ✨

• the kernel file ./sound/soc/fsl/mpc5200_psc_i2s.c — that's where she lives 🏠
• PSC_I2S_RATES(9)
• PSC_I2S_FORMATS(9)
• psc_i2s_set_fmt(9)
• var psc_i2s_dai_ops(9)

go read them, they're all part of the same friend group 💜

---

and that's the page, bestie!! no cap, you're now fully caught up 🦋 — this one's from ./sound/soc/fsl, dated October 2026, and the page itself is psc_i2s_set_sysclk(9). periodt 💅✨👑