/* ESP8266 Xtensa interrupt management functions
 *
 * Some (w/ sdk_ prefix) are implemented in binary libs, rest are
 * inlines replacing functions in the binary libraries.
 *
 * Part of esp-open-rtos
 * Copyright (C) 2015 Superhouse Automation Pty Ltd
 * BSD Licensed as described in the file LICENSE
 */
#ifndef _XTENSA_INTERRUPTS_H
#define _XTENSA_INTERRUPTS_H
#include <stdint.h>
#include <stdbool.h>
#include <xtruntime.h>
#include <xtensa/hal.h>
#include <common_macros.h>

/* Interrupt numbers for level 1 exception handler. */
typedef enum {
    INUM_WDEV_FIQ = 0,
    INUM_SLC = 1,
    INUM_SPI = 2,
    INUM_RTC = 3,
    INUM_GPIO = 4,
    INUM_UART = 5,
    INUM_TICK = 6, /* RTOS timer tick, possibly xtensa CPU CCOMPARE0(?) */
    INUM_SOFT = 7,
    INUM_WDT = 8,
    INUM_TIMER_FRC1 = 9,

    /* FRC2 default handler. Configured by sdk_ets_timer_init, which
       runs as part of default libmain.a startup code, assigns
       interrupt handler to sdk_vApplicationTickHook+0x68
     */
    INUM_TIMER_FRC2 = 10,
} xt_isr_num_t;

void sdk__xt_int_exit(void);
void _xt_user_exit(void);
void sdk__xt_tick_timer_init(void);
void sdk__xt_timer_int(void *);
void sdk__xt_timer_int1(void);

/* The normal running level is 0.
 * The system tick isr, timer frc2_isr, sv_isr etc  run at level 1.
 * Debug exceptions run at level 2?
 * The wdev nmi runs at level 3.
 */
static inline uint32_t _xt_get_intlevel(void)
{
    uint32_t level;
    __asm__ volatile("rsr %0, ps" : "=a"(level));
    return level & 0xf;
}

/*
 * There are conflicting definitions for XCHAL_EXCM_LEVEL. Newlib
 * defines it to be 1 and xtensa_rtos.h defines it to be 3. Don't want
 * 3 as that is for the NMI and might want to check that the OS apis
 * are not entered in level 3. Setting the interrupt level to 3 does
 * not disable the NMI anyway. So set the level to 2.
 */

#ifdef XCHAL_EXCM_LEVEL
#undef XCHAL_EXCM_LEVEL
#define XCHAL_EXCM_LEVEL 2
#endif

/* Disable interrupts and return the old ps value, to pass into
   _xt_restore_interrupts later.

   This is desirable to use in place of
   portDISABLE_INTERRUPTS/portENABLE_INTERRUPTS for
   non-FreeRTOS & non-portable code.
*/
static inline uint32_t _xt_disable_interrupts(void)
{
    uint32_t old_level;
    __asm__ volatile ("rsil %0, " XTSTR(XCHAL_EXCM_LEVEL) : "=a" (old_level));
    return old_level;
}

/* Restore PS level. Intended to be used with _xt_disable_interrupts */
static inline void _xt_restore_interrupts(uint32_t new_ps)
{
    __asm__ volatile ("wsr %0, ps; rsync" :: "a" (new_ps));
}

static inline uint32_t _xt_isr_unmask(uint32_t unmask)
{
    uint32_t old_level = _xt_disable_interrupts();
    uint32_t intenable;
    asm volatile ("rsr %0, intenable" : "=a" (intenable));
    asm volatile ("wsr %0, intenable;" :: "a" (intenable | unmask));
    _xt_restore_interrupts(old_level);
    return intenable;
}

static inline uint32_t _xt_isr_mask(uint32_t mask)
{
    uint32_t old_level = _xt_disable_interrupts();
    uint32_t intenable;
    asm volatile ("rsr %0, intenable" : "=a" (intenable));
    asm volatile ("wsr %0, intenable;" :: "a" (intenable & ~mask));
    _xt_restore_interrupts(old_level);
    return intenable;
}

static inline uint32_t _xt_read_ints(void)
{
    uint32_t interrupt;
    asm volatile ("rsr %0, interrupt" : "=a" (interrupt));
    return interrupt;
}

static inline void _xt_clear_ints(uint32_t mask)
{
    asm volatile ("wsr %0, intclear; esync" :: "a" (mask));
}

typedef void (* _xt_isr)(void *arg);
void _xt_isr_attach (uint8_t i, _xt_isr func, void *arg);

#endif