libexplain  1.4.D001
libexplain/iocontrol/vidioc_dbg_s_register.c
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00001 /*
00002  * libexplain - a library of system-call-specific strerror replacements
00003  * Copyright (C) 2011, 2013 Peter Miller
00004  * Written by Peter Miller <pmiller@opensource.org.au>
00005  *
00006  * This program is free software; you can redistribute it and/or modify it
00007  * under the terms of the GNU Lesser General Public License as published by
00008  * the Free Software Foundation; either version 3 of the License, or (at your
00009  * option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful, but WITHOUT
00012  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00013  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
00014  * License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public License
00017  * along with this program. If not, see <http://www.gnu.org/licenses/>.
00018  */
00019 
00020 #include <libexplain/ac/errno.h>
00021 #include <libexplain/ac/linux/videodev2.h>
00022 #include <libexplain/ac/string.h>
00023 #include <libexplain/ac/sys/ioctl.h>
00024 
00025 #include <libexplain/buffer/dac.h>
00026 #include <libexplain/buffer/einval.h>
00027 #include <libexplain/buffer/eperm.h>
00028 #include <libexplain/buffer/is_the_null_pointer.h>
00029 #include <libexplain/buffer/v4l2_dbg_register.h>
00030 #include <libexplain/buffer/v4l2_register.h>
00031 #include <libexplain/iocontrol/generic.h>
00032 #include <libexplain/iocontrol/vidioc_dbg_s_register.h>
00033 #include <libexplain/is_efault.h>
00034 
00035 #ifdef VIDIOC_DBG_S_REGISTER
00036 
00037 
00038 static void
00039 print_data(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00040     int errnum, int fildes, int request, const void *data)
00041 {
00042     (void)p;
00043     (void)errnum;
00044     (void)fildes;
00045     (void)request;
00046 #ifdef HAVE_V4L2_DBG_REGISTER
00047     explain_buffer_v4l2_dbg_register(sb, data, 1);
00048 #else
00049     explain_buffer_v4l2_register(sb, data, 1);
00050 #endif
00051 }
00052 
00053 
00054 static void
00055 print_explanation(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00056     int errnum, int fildes, int request, const void *data)
00057 {
00058     switch (errnum)
00059     {
00060     case EINVAL:
00061         if (!data)
00062         {
00063             explain_buffer_is_the_null_pointer(sb, "data");
00064             return;
00065         }
00066 
00067         {
00068 #ifdef HAVE_V4L2_DBG_REGISTER
00069             const struct v4l2_dbg_register *arg;
00070             struct v4l2_dbg_register try;
00071 #else
00072             const struct v4l2_register *arg;
00073             struct v4l2_register try;
00074 #endif
00075 
00076             arg = data;
00077             if (explain_is_efault_pointer(arg, sizeof(*arg)))
00078                 goto generic;
00079 
00080             /*
00081              * See if we can fetch the given register.
00082              * If we can, it means the value is broken.
00083              */
00084             try = *arg;
00085             if (ioctl(fildes, VIDIOC_DBG_G_REGISTER, &try) >= 0)
00086             {
00087                 explain_buffer_einval_vague(sb, "data->val");
00088                 return;
00089             }
00090         }
00091 
00092         /*
00093          * It could be the address is broken, or it could be this isn't
00094          * supported.  Let's guess it's the latter.
00095          */
00096         errnum = ENOTTY;
00097         goto generic;
00098 
00099     case EPERM:
00100         explain_buffer_eperm_vague(sb, "ioctl VIDIOC_DBG_S_REGISTER");
00101         explain_buffer_dac_sys_admin(sb);
00102         break;
00103 
00104     default:
00105         generic:
00106         explain_iocontrol_generic_print_explanation
00107         (
00108             p,
00109             sb,
00110             errnum,
00111             fildes,
00112             request,
00113             data
00114         );
00115         break;
00116     }
00117 }
00118 
00119 
00120 static void
00121 print_data_returned(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00122     int errnum, int fildes, int request, const void *data)
00123 {
00124     (void)p;
00125     (void)errnum;
00126     (void)fildes;
00127     (void)request;
00128 #ifdef HAVE_V4L2_DBG_REGISTER
00129     explain_buffer_v4l2_dbg_register(sb, data, 1);
00130 #else
00131     explain_buffer_v4l2_register(sb, data, 1);
00132 #endif
00133 }
00134 
00135 
00136 const explain_iocontrol_t explain_iocontrol_vidioc_dbg_s_register =
00137 {
00138     "VIDIOC_DBG_S_REGISTER", /* name */
00139     VIDIOC_DBG_S_REGISTER, /* value */
00140     0, /* disambiguate */
00141     0, /* print_name */
00142     print_data,
00143     print_explanation,
00144     print_data_returned,
00145 #ifdef HAVE_V4L2_DBG_REGISTER
00146     sizeof(struct v4l2_dbg_register), /* data_size */
00147     "struct v4l2_dbg_register *", /* data_type */
00148 #else
00149     sizeof(struct v4l2_register), /* data_size */
00150     "struct v4l2_register *", /* data_type */
00151 #endif
00152     IOCONTROL_FLAG_RW, /* flags */
00153     __FILE__,
00154     __LINE__,
00155 };
00156 
00157 #else /* ndef VIDIOC_DBG_S_REGISTER */
00158 
00159 const explain_iocontrol_t explain_iocontrol_vidioc_dbg_s_register =
00160 {
00161     0, /* name */
00162     0, /* value */
00163     0, /* disambiguate */
00164     0, /* print_name */
00165     0, /* print_data */
00166     0, /* print_explanation */
00167     0, /* print_data_returned */
00168     0, /* data_size */
00169     0, /* data_type */
00170     0, /* flags */
00171     __FILE__,
00172     __LINE__,
00173 };
00174 
00175 #endif /* VIDIOC_DBG_S_REGISTER */
00176 
00177 /* vim: set ts=8 sw=4 et : */