/*********************************************************************************
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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: led.c
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* Description: This file is used to control RGB 3-colors LED
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* compatible with libgpiod-1.x.x, not compatible with 2.x.x
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*
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*
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* Pin connection:
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* RGB Led Module Raspberry Pi Board
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* R <-----> #Pin33(BCM GPIO13)
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* G <-----> #Pin35(BCM GPIO19)
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* B <-----> #Pin37(BCM GPIO26)
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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 <gpiod.h>
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#include "logger.h"
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#include "leds.h"
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#define DELAY 500
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static led_info_t leds_info[LED_CNT] =
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{
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{"red", 13, 1, NULL },
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{"green", 19, 1, NULL },
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{"blue", 26, 1, NULL },
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};
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int init_led(led_ctx_t *ctx, int which)
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{
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int i, rv;
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led_info_t *led;
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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->leds = leds_info;
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ctx->count = LED_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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if( which == i )
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{
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led = &ctx->leds[i];
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led->line = gpiod_chip_get_line(ctx->chip, led->gpio);
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if( !led->line )
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{
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log_error("open gpioline for %s[%d] failed\n", led->name, led->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(led->line, led->name, !led->active);
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if( rv )
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{
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log_error("request gpio output for %5s[%d] failed: %s\n", led->name, led->gpio, strerror(errno));
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rv = -4;
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goto failed;
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}
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log_debug("request %5s led[%d] for gpio output okay\n", led->name, led->gpio);
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}
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}
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return 0;
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failed:
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term_led(ctx, which);
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return rv;
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}
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int term_led(led_ctx_t *ctx, int which)
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{
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int i;
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led_info_t *led;
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log_warn("terminate RGB Led gpios\n");
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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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if( which == i )
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{
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led = &ctx->leds[i];
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if( led->line )
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gpiod_line_release(led->line);
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}
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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_led(int which, int cmd)
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{
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int rv = 0;
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led_ctx_t ctx;
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led_info_t *led;
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if( which<0 || which>=LED_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_led(&ctx, which)) < 0 )
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{
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log_error("Initial RGB leds failure, rv=%d\n", rv);
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return -2;
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}
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led = &ctx.leds[which];
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if( OFF == cmd )
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{
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gpiod_line_set_value(led->line, !led->active);
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}
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else
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{
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gpiod_line_set_value(led->line, led->active);
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}
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term_led(&ctx, which);
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return 0;
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}
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