/*********************************************************************************
 *      Copyright:  (C) 2021 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  relay.c
 *    Description:  This file is used to control Relay
 *
 *
 * Pin connection:
 *                 Relay Module           Raspberry Pi Board
 *                  VCC       <----->      5V
 *                   I        <----->      #Pin16(BCM GPIO23)
 *                  GND       <----->      GND
 *
 * System install:
 *                  sudo apt install -y libgpiod-dev gpiod
 *
 *
 ********************************************************************************/

#ifndef  _RELAY_H_
#define  _RELAY_H_

#define ON        1
#define OFF       0

/* relay code */
enum
{
    RELAY1 = 0,
    RELAY_CNT,
};

/* Relay hardware information */
typedef struct relay_info_s
{
    const char         *name;  /* Relay name  */
    int                 gpio;  /* Relay BCM pin number */
    int                 active;/* Relay active GPIO level: 0->low 1->high */
    struct gpiod_line  *line;  /* libgpiod line */
} relay_info_t;

/* Relay API context */
typedef struct relay_ctx_s
{
    struct gpiod_chip   *chip;
    relay_info_t        *relay;
    int                  count;
} relay_ctx_t;

extern int init_relay(relay_ctx_t *ctx);
extern int term_relay(relay_ctx_t *ctx);
extern int turn_relay(int which, int cmd);

#endif   /* ----- #ifndef _RELAY_H_  ----- */