drivers/media/video/m52790.c

   1 /*
   2  * m52790 i2c ivtv driver.
   3  * Copyright (C) 2007  Hans Verkuil
   4  *
   5  * A/V source switching Mitsubishi M52790SP/FP
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22
  23 #include <linux/module.h>
  24 #include <linux/types.h>
  25 #include <linux/ioctl.h>
  26 #include <asm/uaccess.h>
  27 #include <linux/i2c.h>
  28 #include <linux/i2c-id.h>
  29 #include <linux/videodev.h>
  30 #include <media/m52790.h>
  31 #include <media/v4l2-common.h>
  32 #include <media/v4l2-chip-ident.h>
  33 #include <media/v4l2-i2c-drv.h>
  34
  35 MODULE_DESCRIPTION("i2c device driver for m52790 A/V switch");
  36 MODULE_AUTHOR("Hans Verkuil");
  37 MODULE_LICENSE("GPL");
  38
  39
  40 struct m52790_state {
  41         u16 input;
  42         u16 output;
  43 };
  44
  45 /* ----------------------------------------------------------------------- */
  46
  47 static int m52790_write(struct i2c_client *client)
  48 {
  49         struct m52790_state *state = i2c_get_clientdata(client);
  50         u8 sw1 = (state->input | state->output) & 0xff;
  51         u8 sw2 = (state->input | state->output) >> 8;
  52
  53         return i2c_smbus_write_byte_data(client, sw1, sw2);
  54 }
  55
  56 static int m52790_command(struct i2c_client *client, unsigned int cmd,
  57                             void *arg)
  58 {
  59         struct m52790_state *state = i2c_get_clientdata(client);
  60         struct v4l2_routing *route = arg;
  61
  62         /* Note: audio and video are linked and cannot be switched separately.
  63            So audio and video routing commands are identical for this chip.
  64            In theory the video amplifier and audio modes could be handled
  65            separately for the output, but that seems to be overkill right now.
  66            The same holds for implementing an audio mute control, this is now
  67            part of the audio output routing. The normal case is that another
  68            chip takes care of the actual muting so making it part of the
  69            output routing seems to be the right thing to do for now. */
  70         switch (cmd) {
  71         case VIDIOC_INT_G_AUDIO_ROUTING:
  72         case VIDIOC_INT_G_VIDEO_ROUTING:
  73                 route->input = state->input;
  74                 route->output = state->output;
  75                 break;
  76
  77         case VIDIOC_INT_S_AUDIO_ROUTING:
  78         case VIDIOC_INT_S_VIDEO_ROUTING:
  79                 state->input = route->input;
  80                 state->output = route->output;
  81                 m52790_write(client);
  82                 break;
  83
  84 #ifdef CONFIG_VIDEO_ADV_DEBUG
  85         case VIDIOC_DBG_G_REGISTER:
  86         case VIDIOC_DBG_S_REGISTER:
  87         {
  88                 struct v4l2_register *reg = arg;
  89
  90                 if (!v4l2_chip_match_i2c_client(client,
  91                                         reg->match_type, reg->match_chip))
  92                         return -EINVAL;
  93                 if (!capable(CAP_SYS_ADMIN))
  94                         return -EPERM;
  95                 if (reg->reg != 0)
  96                         return -EINVAL;
  97                 if (cmd == VIDIOC_DBG_G_REGISTER)
  98                         reg->val = state->input | state->output;
  99                 else {
 100                         state->input = reg->val & 0x0303;
 101                         state->output = reg->val & ~0x0303;
 102                         m52790_write(client);
 103                 }
 104                 break;
 105         }
 106 #endif
 107
 108         case VIDIOC_G_CHIP_IDENT:
 109                 return v4l2_chip_ident_i2c_client(client, arg,
 110                                 V4L2_IDENT_M52790, 0);
 111
 112         case VIDIOC_LOG_STATUS:
 113                 v4l_info(client, "Switch 1: %02x\n",
 114                                 (state->input | state->output) & 0xff);
 115                 v4l_info(client, "Switch 2: %02x\n",
 116                                 (state->input | state->output) >> 8);
 117                 break;
 118
 119         default:
 120                 return -EINVAL;
 121         }
 122         return 0;
 123 }
 124
 125 /* ----------------------------------------------------------------------- */
 126
 127 /* i2c implementation */
 128
 129 static int m52790_probe(struct i2c_client *client)
 130 {
 131         struct m52790_state *state;
 132
 133         /* Check if the adapter supports the needed features */
 134         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 135                 return -EIO;
 136
 137         snprintf(client->name, sizeof(client->name) - 1, "m52790");
 138
 139         v4l_info(client, "chip found @ 0x%x (%s)\n",
 140                         client->addr << 1, client->adapter->name);
 141
 142         state = kmalloc(sizeof(struct m52790_state), GFP_KERNEL);
 143         if (state == NULL)
 144                 return -ENOMEM;
 145
 146         state->input = M52790_IN_TUNER;
 147         state->output = M52790_OUT_STEREO;
 148         i2c_set_clientdata(client, state);
 149         m52790_write(client);
 150         return 0;
 151 }
 152
 153 static int m52790_remove(struct i2c_client *client)
 154 {
 155         kfree(i2c_get_clientdata(client));
 156         return 0;
 157 }
 158
 159 /* ----------------------------------------------------------------------- */
 160
 161 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
 162         .name = "m52790",
 163         .driverid = I2C_DRIVERID_M52790,
 164         .command = m52790_command,
 165         .probe = m52790_probe,
 166         .remove = m52790_remove,
 167 };
 168