#!perl
use strict;
use warnings;
use Data::Dumper;

my $id = '1C8962EB';
myfunction($id, { max => 90, cval => 89 });
sub myfunction {
    my %p = %{$_[1]};
    print Dumper(\%p);
    my %newp = map { $_ => { value => $p{$_}, key => $_, id => $_[0] } } keys %p;
    print Dumper(\%newp);
}
__END__
$VAR1 = {
          'max' => 90,
          'cval' => 89
        };
$VAR1 = {
          'cval' => {
                      'value' => 89,
                      'id' => '1C8962EB',
                      'key' => 'cval'
                    },
          'max' => {
                     'value' => 90,
                     'id' => '1C8962EB',
                     'key' => 'max'
                   }
        };