/*********************************************************************************
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* Copyright: (C) 2021 LingYun IoT System Studio
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* All rights reserved.
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*
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* Filename: relay.c
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* Description: This file is used to control Relay
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*
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*
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* Pin connection:
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* Relay Module Raspberry Pi Board
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* VCC <-----> 5V
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* I <-----> #Pin16(BCM GPIO23)
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* GND <-----> GND
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*
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* System install:
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* sudo apt install -y libgpiod-dev gpiod
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*
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*
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********************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <dirent.h>
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#include <string.h>
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#include <time.h>
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#include <errno.h>
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#include <signal.h>
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#include <getopt.h>
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#include <libgen.h>
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#include <gpiod.h>
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#include "logger.h"
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#include "relay.h"
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#define DELAY 500
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static relay_info_t relay_info[RELAY_CNT] =
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{
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{"relay1", 23, 1, NULL },
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};
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int init_relay(relay_ctx_t *ctx)
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{
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int i, rv;
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relay_info_t *relay;
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if( !ctx )
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{
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log_error("Invalid input arguments\n");
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return -1;
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}
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ctx->relay = relay_info;
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ctx->count = RELAY_CNT;
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ctx->chip = gpiod_chip_open_by_name("gpiochip0");
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if( !ctx->chip )
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{
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log_error("open gpiochip failure, maybe you need running as root\n");
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return -2;
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}
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for(i=0; i<ctx->count; i++)
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{
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relay = &ctx->relay[i];
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relay->line = gpiod_chip_get_line(ctx->chip, relay->gpio);
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if( !relay->line )
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{
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log_error("open gpioline for %s[%d] failed\n", relay->name, relay->gpio);
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rv = -3;
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goto failed;
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}
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rv = gpiod_line_request_output(relay->line, relay->name, !relay->active);
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if( rv )
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{
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log_error("request gpio output for %5s[%d] failed\n", relay->name, relay->gpio);
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rv = -4;
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goto failed;
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}
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log_debug("request %s[%d] for gpio output okay\n", relay->name, relay->gpio);
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}
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return 0;
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failed:
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term_relay(ctx);
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return rv;
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}
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int term_relay(relay_ctx_t *ctx)
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{
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int i;
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relay_info_t *relay;
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if( !ctx )
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{
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log_error("Invalid input arguments\n");
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return -1;
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}
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if( !ctx->chip )
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return 0;
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for(i=0; i<ctx->count; i++)
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{
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relay = &ctx->relay[i];
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if( relay->line )
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gpiod_line_release(relay->line);
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}
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gpiod_chip_close(ctx->chip);
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return 0;
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}
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int turn_relay(int which, int cmd)
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{
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int rv = 0;
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relay_info_t *relay;
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relay_ctx_t ctx;
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if( which<0 || which>=RELAY_CNT )
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{
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log_error("Invalid input arguments\n");
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return -1;
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}
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if( (rv=init_relay(&ctx)) < 0 )
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{
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log_error("Initial relay failure, rv=%d\n", rv);
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return -2;
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}
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relay = &ctx.relay[which];
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if( OFF == cmd )
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{
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gpiod_line_set_value(relay->line, !relay->active);
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}
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else
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{
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gpiod_line_set_value(relay->line, relay->active);
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}
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term_relay(&ctx);
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return 0;
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}
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