spmi.c

#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/UefiBootServicesTableLib.h>

#define CORE   0x0c440000
#define OBSRVR 0x0e600000

#define PMIC_USID 4 // PM6150L GPIO USID
#define PMIC_GPIO_BASE 0xC000 // PM6150L GPIO address
#define VOL_UP_GPIO 2

UINT32 channel_map[16][256];

EFI_STATUS
EFIAPI
Entry (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE *SystemTable)
{
    EFI_STATUS Status = EFI_SUCCESS;

    UINT32 Version = MmioRead32(CORE);

    DEBUG((EFI_D_ERROR, "PMIC ARB Version: 0x%X\n", Version));

    gBS->SetMem(channel_map, 16 * 256, 0);

    for(UINT16 i = 0; i < 512; i++) {
        UINT32 periph = MmioRead32(CORE + 0x900 + (0x4 * i));
        UINT8 slave_id = (periph & 0xf0000) >> 16;
        UINT8 pid = (periph & 0xff00) >> 8;
        channel_map[slave_id][pid] = i;
    }

    UINT32 pid = GPIO_BASE + (VOL_UP_GPIO - 1) * 0x100 + 0x8;
    UINT32 channel = channel_map[PMIC_USID][(pid & (0xFF << 8)) >> 8] & 0xffff;
    DEBUG((EFI_D_ERROR, "Channel: 0x%X\n", OBSRVR + channel * 0x80));
    DEBUG((EFI_D_ERROR, "Command: 0x%X\n", (0x8000001 | ((pid & 0xFF) << 4))));

    while(1) {}
    return Status;
}