xref: /openbmc/linux/drivers/media/rc/ir-sanyo-decoder.c (revision 812f77b749a8ae11f58dacf0d3ed65e7ede47458)
1 /* ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
2  *
3  * Copyright (C) 2011 by Mauro Carvalho Chehab
4  *
5  * This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation version 2 of the License.
8  *
9  *  This program is distributed in the hope that it will be useful,
10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *  GNU General Public License for more details.
13  *
14  * This protocol uses the NEC protocol timings. However, data is formatted as:
15  *	13 bits Custom Code
16  *	13 bits NOT(Custom Code)
17  *	8 bits Key data
18  *	8 bits NOT(Key data)
19  *
20  * According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon
21  * Information for this protocol is available at the Sanyo LC7461 datasheet.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/bitrev.h>
26 #include "rc-core-priv.h"
27 
28 #define SANYO_NBITS		(13+13+8+8)
29 #define SANYO_UNIT		562500  /* ns */
30 #define SANYO_HEADER_PULSE	(16  * SANYO_UNIT)
31 #define SANYO_HEADER_SPACE	(8   * SANYO_UNIT)
32 #define SANYO_BIT_PULSE		(1   * SANYO_UNIT)
33 #define SANYO_BIT_0_SPACE	(1   * SANYO_UNIT)
34 #define SANYO_BIT_1_SPACE	(3   * SANYO_UNIT)
35 #define SANYO_REPEAT_SPACE	(150 * SANYO_UNIT)
36 #define	SANYO_TRAILER_PULSE	(1   * SANYO_UNIT)
37 #define	SANYO_TRAILER_SPACE	(10  * SANYO_UNIT)	/* in fact, 42 */
38 
39 enum sanyo_state {
40 	STATE_INACTIVE,
41 	STATE_HEADER_SPACE,
42 	STATE_BIT_PULSE,
43 	STATE_BIT_SPACE,
44 	STATE_TRAILER_PULSE,
45 	STATE_TRAILER_SPACE,
46 };
47 
48 /**
49  * ir_sanyo_decode() - Decode one SANYO pulse or space
50  * @dev:	the struct rc_dev descriptor of the device
51  * @duration:	the struct ir_raw_event descriptor of the pulse/space
52  *
53  * This function returns -EINVAL if the pulse violates the state machine
54  */
55 static int ir_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev)
56 {
57 	struct sanyo_dec *data = &dev->raw->sanyo;
58 	u32 scancode;
59 	u16 address;
60 	u8 command, not_command;
61 
62 	if (!is_timing_event(ev)) {
63 		if (ev.reset) {
64 			IR_dprintk(1, "SANYO event reset received. reset to state 0\n");
65 			data->state = STATE_INACTIVE;
66 		}
67 		return 0;
68 	}
69 
70 	IR_dprintk(2, "SANYO decode started at state %d (%uus %s)\n",
71 		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
72 
73 	switch (data->state) {
74 
75 	case STATE_INACTIVE:
76 		if (!ev.pulse)
77 			break;
78 
79 		if (eq_margin(ev.duration, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) {
80 			data->count = 0;
81 			data->state = STATE_HEADER_SPACE;
82 			return 0;
83 		}
84 		break;
85 
86 
87 	case STATE_HEADER_SPACE:
88 		if (ev.pulse)
89 			break;
90 
91 		if (eq_margin(ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) {
92 			data->state = STATE_BIT_PULSE;
93 			return 0;
94 		}
95 
96 		break;
97 
98 	case STATE_BIT_PULSE:
99 		if (!ev.pulse)
100 			break;
101 
102 		if (!eq_margin(ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2))
103 			break;
104 
105 		data->state = STATE_BIT_SPACE;
106 		return 0;
107 
108 	case STATE_BIT_SPACE:
109 		if (ev.pulse)
110 			break;
111 
112 		if (!data->count && geq_margin(ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) {
113 			rc_repeat(dev);
114 			IR_dprintk(1, "SANYO repeat last key\n");
115 			data->state = STATE_INACTIVE;
116 			return 0;
117 		}
118 
119 		data->bits <<= 1;
120 		if (eq_margin(ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2))
121 			data->bits |= 1;
122 		else if (!eq_margin(ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2))
123 			break;
124 		data->count++;
125 
126 		if (data->count == SANYO_NBITS)
127 			data->state = STATE_TRAILER_PULSE;
128 		else
129 			data->state = STATE_BIT_PULSE;
130 
131 		return 0;
132 
133 	case STATE_TRAILER_PULSE:
134 		if (!ev.pulse)
135 			break;
136 
137 		if (!eq_margin(ev.duration, SANYO_TRAILER_PULSE, SANYO_UNIT / 2))
138 			break;
139 
140 		data->state = STATE_TRAILER_SPACE;
141 		return 0;
142 
143 	case STATE_TRAILER_SPACE:
144 		if (ev.pulse)
145 			break;
146 
147 		if (!geq_margin(ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2))
148 			break;
149 
150 		address     = bitrev16((data->bits >> 29) & 0x1fff) >> 3;
151 		/* not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3; */
152 		command	    = bitrev8((data->bits >>  8) & 0xff);
153 		not_command = bitrev8((data->bits >>  0) & 0xff);
154 
155 		if ((command ^ not_command) != 0xff) {
156 			IR_dprintk(1, "SANYO checksum error: received 0x%08Lx\n",
157 				   data->bits);
158 			data->state = STATE_INACTIVE;
159 			return 0;
160 		}
161 
162 		scancode = address << 8 | command;
163 		IR_dprintk(1, "SANYO scancode: 0x%06x\n", scancode);
164 		rc_keydown(dev, RC_PROTO_SANYO, scancode, 0);
165 		data->state = STATE_INACTIVE;
166 		return 0;
167 	}
168 
169 	IR_dprintk(1, "SANYO decode failed at count %d state %d (%uus %s)\n",
170 		   data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
171 	data->state = STATE_INACTIVE;
172 	return -EINVAL;
173 }
174 
175 static const struct ir_raw_timings_pd ir_sanyo_timings = {
176 	.header_pulse  = SANYO_HEADER_PULSE,
177 	.header_space  = SANYO_HEADER_SPACE,
178 	.bit_pulse     = SANYO_BIT_PULSE,
179 	.bit_space[0]  = SANYO_BIT_0_SPACE,
180 	.bit_space[1]  = SANYO_BIT_1_SPACE,
181 	.trailer_pulse = SANYO_TRAILER_PULSE,
182 	.trailer_space = SANYO_TRAILER_SPACE,
183 	.msb_first     = 1,
184 };
185 
186 /**
187  * ir_sanyo_encode() - Encode a scancode as a stream of raw events
188  *
189  * @protocol:	protocol to encode
190  * @scancode:	scancode to encode
191  * @events:	array of raw ir events to write into
192  * @max:	maximum size of @events
193  *
194  * Returns:	The number of events written.
195  *		-ENOBUFS if there isn't enough space in the array to fit the
196  *		encoding. In this case all @max events will have been written.
197  */
198 static int ir_sanyo_encode(enum rc_proto protocol, u32 scancode,
199 			   struct ir_raw_event *events, unsigned int max)
200 {
201 	struct ir_raw_event *e = events;
202 	int ret;
203 	u64 raw;
204 
205 	raw = ((u64)(bitrev16(scancode >> 8) & 0xfff8) << (8 + 8 + 13 - 3)) |
206 	      ((u64)(bitrev16(~scancode >> 8) & 0xfff8) << (8 + 8 +  0 - 3)) |
207 	      ((bitrev8(scancode) & 0xff) << 8) |
208 	      (bitrev8(~scancode) & 0xff);
209 
210 	ret = ir_raw_gen_pd(&e, max, &ir_sanyo_timings, SANYO_NBITS, raw);
211 	if (ret < 0)
212 		return ret;
213 
214 	return e - events;
215 }
216 
217 static struct ir_raw_handler sanyo_handler = {
218 	.protocols	= RC_PROTO_BIT_SANYO,
219 	.decode		= ir_sanyo_decode,
220 	.encode		= ir_sanyo_encode,
221 };
222 
223 static int __init ir_sanyo_decode_init(void)
224 {
225 	ir_raw_handler_register(&sanyo_handler);
226 
227 	printk(KERN_INFO "IR SANYO protocol handler initialized\n");
228 	return 0;
229 }
230 
231 static void __exit ir_sanyo_decode_exit(void)
232 {
233 	ir_raw_handler_unregister(&sanyo_handler);
234 }
235 
236 module_init(ir_sanyo_decode_init);
237 module_exit(ir_sanyo_decode_exit);
238 
239 MODULE_LICENSE("GPL");
240 MODULE_AUTHOR("Mauro Carvalho Chehab");
241 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
242 MODULE_DESCRIPTION("SANYO IR protocol decoder");
243