pinctrl: aspeed: Add AST2700 SoC1 pinctrl driver

Add the pinctrl driver for the AST2700 SoC1 (I/O) die.

Unlike previous Aspeed generations, the SoC1 SCU assigns every pin a
4-bit multi-function selector field in a contiguous register range
starting at SCU 0x400, eight pins per register. Only bits [2:0] of
each field select the function; bit 3 is reserved read-only and must
not be written. The driver therefore keeps per-pin group tables and
per-function mux values, mirroring the Linux
aspeed,ast2700-soc1-pinctrl driver, and shares the same device tree
bindings: 220 pins, 238 groups and 217 functions with identical names,
so pin states written for the Linux driver work unmodified.

A few controls live outside the pin-indexed range and are handled as
virtual pins: PCIERC2_PERST (SCU 0x908), the USB2 port C/D mode fields
(SCU 0x3B0) and SGMII0 (SCU 0x47C).

The gpio_request_enable hook restores a pin to GPIO by writing mux
value 0, except for the ADC-capable balls W17..AB19 where function 1
selects GPIO and 0 selects the ADC input.

Signed-off-by: Billy Tsai <[email protected]>

0 files changed, 0 insertions, 0 deletions