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_client_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 	i2c_unregister_device(dev->ir_i2c_client);
100 	dev->ir_i2c_client = NULL;
101 }
102