drivers/media/usb/cx231xx/cx231xx-input.c

   1 /*
   2  *   cx231xx IR glue driver
   3  *
   4  *   Copyright (C) 2010 Mauro Carvalho Chehab
   5  *
   6  *   Polaris (cx231xx) has its support for IR's with a design close to MCE.
   7  *   however, a few designs are using an external I2C chip for IR, instead
   8  *   of using the one provided by the chip.
   9  *   This driver provides support for those extra devices
  10  *
  11  *   This program is free software; you can redistribute it and/or
  12  *   modify it under the terms of the GNU General Public License as
  13  *   published by the Free Software Foundation version 2.
  14  *
  15  *   This program is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *   General Public License for more details.
  19  */
  20
  21 #include "cx231xx.h"
  22 #include <linux/slab.h>
  23 #include <linux/bitrev.h>
  24
  25 #define MODULE_NAME "cx231xx-input"
  26
  27 static int get_key_isdbt(struct IR_i2c *ir, enum rc_type *protocol,
  28                          u32 *pscancode, u8 *toggle)
  29 {
  30         int     rc;
  31         u8      cmd, scancode;
  32
  33         dev_dbg(&ir->rc->input_dev->dev, "%s\n", __func__);
  34
  35                 /* poll IR chip */
  36         rc = i2c_master_recv(ir->c, &cmd, 1);
  37         if (rc < 0)
  38                 return rc;
  39         if (rc != 1)
  40                 return -EIO;
  41
  42         /* it seems that 0xFE indicates that a button is still hold
  43            down, while 0xff indicates that no button is hold
  44            down. 0xfe sequences are sometimes interrupted by 0xFF */
  45
  46         if (cmd == 0xff)
  47                 return 0;
  48
  49         scancode = bitrev8(cmd);
  50
  51         dev_dbg(&ir->rc->input_dev->dev, "cmd %02x, scan = %02x\n",
  52                 cmd, scancode);
  53
  54         *protocol = RC_TYPE_OTHER;
  55         *pscancode = scancode;
  56         *toggle = 0;
  57         return 1;
  58 }
  59
  60 int cx231xx_ir_init(struct cx231xx *dev)
  61 {
  62         struct i2c_board_info info;
  63         u8 ir_i2c_bus;
  64
  65         dev_dbg(dev->dev, "%s\n", __func__);
  66
  67         /* Only initialize if a rc keycode map is defined */
  68         if (!cx231xx_boards[dev->model].rc_map_name)
  69                 return -ENODEV;
  70
  71         request_module("ir-kbd-i2c");
  72
  73         memset(&info, 0, sizeof(struct i2c_board_info));
  74         memset(&dev->init_data, 0, sizeof(dev->init_data));
  75         dev->init_data.rc_dev = rc_allocate_device(RC_DRIVER_SCANCODE);
  76         if (!dev->init_data.rc_dev)
  77                 return -ENOMEM;
  78
  79         dev->init_data.name = cx231xx_boards[dev->model].name;
  80
  81         strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
  82         info.platform_data = &dev->init_data;
  83
  84         /*
  85          * Board-dependent values
  86          *
  87          * For now, there's just one type of hardware design using
  88          * an i2c device.
  89          */
  90         dev->init_data.get_key = get_key_isdbt;
  91         dev->init_data.ir_codes = cx231xx_boards[dev->model].rc_map_name;
  92         /* The i2c micro-controller only outputs the cmd part of NEC protocol */
  93         dev->init_data.rc_dev->scancode_mask = 0xff;
  94         dev->init_data.rc_dev->driver_name = "cx231xx";
  95         dev->init_data.type = RC_BIT_NEC;
  96         info.addr = 0x30;
  97
  98         /* Load and bind ir-kbd-i2c */
  99         ir_i2c_bus = cx231xx_boards[dev->model].ir_i2c_master;
 100         dev_dbg(dev->dev, "Trying to bind ir at bus %d, addr 0x%02x\n",
 101                 ir_i2c_bus, info.addr);
 102         dev->ir_i2c_client = i2c_new_device(
 103                 cx231xx_get_i2c_adap(dev, ir_i2c_bus), &info);
 104
 105         return 0;
 106 }
 107
 108 void cx231xx_ir_exit(struct cx231xx *dev)
 109 {
 110         if (dev->ir_i2c_client)
 111                 i2c_unregister_device(dev->ir_i2c_client);
 112         dev->ir_i2c_client = NULL;
 113 }