// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once

// ACPI, in two layers.
//
// kernel/arch/x86_64/acpi.c reads the static tables at boot, before anything
// else can run: the MADT for the processors and the I/O APIC and its
// interrupt source overrides, the FADT for the PM timer.
//
// kernel/acpi/ is everything that needs AML, which is the firmware's own code
// and has to be interpreted: uACPI (ports/uacpi) runs it, and aml.c uses it
// for PCI interrupt routing, the power button, power-off and reset. Every
// function below that depends on it does nothing, and says so by returning
// -1, on a machine whose AML could not be loaded.

// The RSDP's physical address, or 0 if there is none.
uint64 acpi_rsdp_phys(void);

// The GSI an ISA IRQ is wired to, after the MADT's interrupt source
// overrides, and its trigger mode (an IRQ_* from irq.h) in *mode. `dflt` is
// the mode when the override says "conforms to the bus" or there is none:
// edge/high for an ISA device, level/low for the SCI.
int    acpi_isa_gsi(int isa, int dflt, int *mode);

// Load and initialize the namespace. After kinit, before pci_init.
void   acpi_aml_init(void);
// The worker thread that runs AML on behalf of interrupts. After sinit.
void   acpi_thread_start(void);
// Route every PCI device's INTx through _PRT. From pci_init, before binding.
void   acpi_pci_route(void);

int    acpi_poweroff(void);     // S5; returns only on failure
void   acpi_poweroff_now(void); // S5 from a panic, no AML; returns only on failure
int    acpi_reboot(void);       // the FADT reset register; ditto

// Batteries and AC adapters, for /sys/class/power_supply. Units are the
// battery's own: unit 0 is mW/mWh, 1 is mA/mAh; ACPI_UNKNOWN where the
// firmware does not say.
#define ACPI_UNKNOWN 0xFFFFFFFFu
struct acpi_psu {
  int    battery;           // else an AC adapter
  int    present;           // battery: in the bay
  int    online;            // adapter: plugged in
  int    unit;
  uint32 state;             // _BST: 1 discharging, 2 charging, 4 critical
  uint32 rate, remaining, voltage;          // _BST, voltage in mV
  uint32 design, full, design_voltage, cycles;
  int    technology;        // 0 primary, 1 rechargeable
  char   model[32], serial[32], kind[16], oem[32];
};
int    acpi_psu_count(void);
int    acpi_psu_get(int i, struct acpi_psu *out);

// How an idle CPU sleeps: kernel/acpi/aml.c reads it from _CST, and the
// scheduler's idle path in kernel/proc/proc.c acts on it.
#define ACPI_IDLE_HLT   0
#define ACPI_IDLE_IO    1       // read a port
#define ACPI_IDLE_MWAIT 2       // MWAIT with a hint
struct acpi_idle {
  int    kind;
  uint64 addr;                  // the port, or the MWAIT hint
  uint   latency;               // microseconds
};
extern struct acpi_idle acpi_idle;