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

   1 // SPDX-License-Identifier: GPL-2.0
   2 // cx231xx IR glue driver
   3 //
   4 // Copyright (c) 2010 Mauro Carvalho Chehab <mchehab@kernel.org>
   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 #include "cx231xx.h"
  12 #include <linux/slab.h>
  13 #include <linux/bitrev.h>
  14
  15 #define MODULE_NAME "cx231xx-input"
  16
  17 static int get_key_isdbt(struct IR_i2c *ir, enum rc_proto *protocol,
  18                          u32 *pscancode, u8 *toggle)
  19 {
  20         int     rc;
  21         u8      cmd, scancode;
  22
  23         dev_dbg(&ir->rc->dev, "%s\n", __func__);
  24
  25                 /* poll IR chip */
  26         rc = i2c_master_recv(ir->c, &cmd, 1);
  27         if (rc < 0)
  28                 return rc;
  29         if (rc != 1)
  30                 return -EIO;
  31
  32         /* it seems that 0xFE indicates that a button is still hold
  33            down, while 0xff indicates that no button is hold
  34            down. 0xfe sequences are sometimes interrupted by 0xFF */
  35
  36         if (cmd == 0xff)
  37                 return 0;
  38
  39         scancode = bitrev8(cmd);
  40
  41         dev_dbg(&ir->rc->dev, "cmd %02x, scan = %02x\n", cmd, scancode);
  42
  43         *protocol = RC_PROTO_OTHER;
  44         *pscancode = scancode;
  45         *toggle = 0;
  46         return 1;
  47 }
  48
  49 int cx231xx_ir_init(struct cx231xx *dev)
  50 {
  51         struct i2c_board_info info;
  52         u8 ir_i2c_bus;
  53
  54         dev_dbg(dev->dev, "%s\n", __func__);
  55
  56         /* Only initialize if a rc keycode map is defined */
  57         if (!cx231xx_boards[dev->model].rc_map_name)
  58                 return -ENODEV;
  59
  60         request_module("ir-kbd-i2c");
  61
  62         memset(&info, 0, sizeof(struct i2c_board_info));
  63         memset(&dev->init_data, 0, sizeof(dev->init_data));
  64         dev->init_data.rc_dev = rc_allocate_device(RC_DRIVER_SCANCODE);
  65         if (!dev->init_data.rc_dev)
  66                 return -ENOMEM;
  67
  68         dev->init_data.name = cx231xx_boards[dev->model].name;
  69
  70         strscpy(info.type, "ir_video", I2C_NAME_SIZE);
  71         info.platform_data = &dev->init_data;
  72
  73         /*
  74          * Board-dependent values
  75          *
  76          * For now, there's just one type of hardware design using
  77          * an i2c device.
  78          */
  79         dev->init_data.get_key = get_key_isdbt;
  80         dev->init_data.ir_codes = cx231xx_boards[dev->model].rc_map_name;
  81         /* The i2c micro-controller only outputs the cmd part of NEC protocol */
  82         dev->init_data.rc_dev->scancode_mask = 0xff;
  83         dev->init_data.rc_dev->driver_name = "cx231xx";
  84         dev->init_data.type = RC_PROTO_BIT_NEC;
  85         info.addr = 0x30;
  86
  87         /* Load and bind ir-kbd-i2c */
  88         ir_i2c_bus = cx231xx_boards[dev->model].ir_i2c_master;
  89         dev_dbg(dev->dev, "Trying to bind ir at bus %d, addr 0x%02x\n",
  90                 ir_i2c_bus, info.addr);
  91         dev->ir_i2c_client = i2c_new_device(
  92                 cx231xx_get_i2c_adap(dev, ir_i2c_bus), &info);
  93
  94         return 0;
  95 }
  96
  97 void cx231xx_ir_exit(struct cx231xx *dev)
  98 {
  99         if (dev->ir_i2c_client)
 100                 i2c_unregister_device(dev->ir_i2c_client);
 101         dev->ir_i2c_client = NULL;
 102 }