sppctl_gmx_set(9)

hey bestie 💖 welcome to sppctl_gmx_set(9) from the Kernel API Manual — aka the little kernel function whose whole job is setting a pin of a group-pinmux. It’s giving “small function, very specific task” energy and we respect it 💅

✨ NAME ✨

sppctl_gmx_set — Set pin of group-pinmux. That’s literally the name, no cap 🎀

🌸 SYNOPSIS 🌸

void sppctl_gmx_set (struct sppctl_pdata *pctl , u8 reg_off , u8 bit_off
, u8 bit_sz , u8 val );

It returns void, so there’s no return value to obsess over — it just does the thing 😌

🎀 ARGUMENTS 🎀

The manpage is so real for this: every single argument is marked -- undescribed --. No lore, no extra details, just vibes 🙈

• pctl — -- undescribed --
• reg_off — -- undescribed --
• bit_off — -- undescribed --
• bit_sz — -- undescribed --
• val — -- undescribed --

🦋 DESCRIPTION 🦋

okay so the mask-fields and control-fields of the group-pinmux function of SP7021 are arranged as shown below. The columns are register, mask-fields, and control-fields:

• base[0] → mask-fields (31 : 16), control-fields (15 : 0)
• base[1] → mask-fields (31 : 24), control-fields (15 : 0)
• base[2] → mask-fields (31 : 24), control-fields (15 : 0)
• : → mask-fields :, control-fields :

where mask-fields are used to protect control-fields from write-in accidentally 🛡️ — yes, that’s the page’s words, and honestly it ate. Set the corresponding bits in the mask-field before you write a value into a control-field. No skipping the shield step, bestie 💅

Control-fields are used to set where the function pin is going to be routed to 📍. A control-field consists of one or more bits — tiny field, big routing decisions, periodt.

💜 SEE ALSO 💜

• Kernel file ./drivers/pinctrl/sunplus/sppctl.c
• sppctl_func_set(9)
• sppctl_first_get(9)
• sppctl_master_get(9)
• sppctl_fully_pinmux_conv(9)

mwah 💖 this cutie lives in the Kernel API Manual, source/version path ./drivers/pinctrl/sunplus, dated October 2026, and the page is literally sppctl_gmx_set(9) — periodt 🎀✨