/* 
 * File:   dellAlsCtl.c
 * Author: yelo3
 *
 * Created on 2 marzo 2009, 9.51
 */

/*
 SMI Interface:

    cbClass:  17
    cbSelect: 10
    Name:     Ambient Light Sensor Status and Control

    On entry:
    cbARG1, byte 0: Function to perform:
        0   Get ALS Status
        1   Control ALS
        2   Get Brightness Table

    If cbARG1, byte 0 is 1 (Control ALS):
    cbARG2, byte 0: Command
        0   Disable ALS
        1   Enable ALS
    cbARG2, byte 1: ALS low limit to set
    cbARG2, byte 2: ALS high limit to set

    On return:
    cbRES1: Return code
        0   Completed successfully
        -1  Completed with error
        -2  Function not supported

    If cbARG1 byte 0 was 0 (Get ALS Status):
    cbRES2, byte 0: Current ALS Status
        0   Disabled
        1   Enabled
    cbRES3, byte 0: Current ALS low limit
    cbRES3, byte 1: Current ALS high limit
    cbRES3, byte 2: Absolute ALS low limit
    cbRES3, byte 3: Absolute ALS high limit

    If cbARG1 byte 0 was 2 (Get Brightness Table):
    cbRES2: Bytes 3..0 of the brightness table
    cbRES3: Bytes 7..4 of the brightness table

 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#include <smi.h>

#define ALS_CB_CLASS  17
#define ALS_CB_SELECT 10

int parse_result(int r, u32 res_0)
{
    if (r == -1)
    {
        perror("You need root access");
    }
    else if (r != 0)
    {
        perror("Error");
    }

    else if (res_0 == -1)
    {
        fprintf(stderr, "Completed with error\n");
        exit(-1);
    }

    else if (res_0 == -2)
    {
        fprintf(stderr, "Function not supported\n");
        exit(-2);
    }

    if (r != 0)
        exit(EXIT_FAILURE);
}

void print_current_status()
{
    u32 args[1] = {0};
    u32 res[4];

    int r = dell_simple_ci_smi(ALS_CB_CLASS, ALS_CB_SELECT, args, res);

    parse_result(r, res[0]);

    printf("ALS enabled: %d\n", res[1] % 256);
        
    /*
     * commented because it's always 0
    printf("Current ALS low limit: %d\n", res[2] % 256);
    printf("Current ALS high limit: %d\n", ( res[2] >> 1*8 ) % 256);
    printf("Absolute ALS low limit: %d\n", ( res[2] >> 2*8 ) % 256);
    printf("Absolute ALS high limit: %d\n", ( res[2] >> 3*8 ) % 256);
    */
}

void set_current_status(bool enabled)
{
    u32 args[2] = {1, 0};
    u32 res[4];

    printf("Changing status to %d\n", enabled);

    if (enabled == true)
    {
        args[1] = 1;
    }

    int r = dell_simple_ci_smi(ALS_CB_CLASS, ALS_CB_SELECT, args, res);

    parse_result(r, res[0]);
}

/*
 * 
 */
int main(int argc, char** argv) {

    if (argc != 2)
    {
        printf("usage options:\n"
                "--status\t\tPrints current ambient light sensor status\n"
                "--enable\t\tEnable the ambient light sensor\n"
                "--disable\t\tDisable the ambient light sensor\n"
                );

        exit(EXIT_FAILURE);
    }

    int enable;

    if (strcmp(argv[1], "--status") == 0)
        enable = -1;
    if (strcmp(argv[1], "--enable") == 0)
        enable = 1;
    else if (strcmp(argv[1], "--disable") == 0)
        enable = 0;

    if (enable == -1)
    {
        print_current_status();
    }

    else if (enable == 1)
    {
        set_current_status(true);
        print_current_status();
    }
    else if (enable == 0)
    {
        set_current_status(false);
        print_current_status();
    }

    return (EXIT_SUCCESS);
}