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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Loopback driver for rc-core,
4 *
5 * Copyright (c) 2010 David Härdeman <[email protected]>
6 *
7 * This driver receives TX data and passes it back as RX data,
8 * which is useful for (scripted) debugging of rc-core without
9 * having to use actual hardware.
10 */
11
12#include <linux/device.h>
13#include <linux/module.h>
14#include <linux/sched.h>
15#include <linux/slab.h>
16#include <media/rc-core.h>
17
18#define DRIVER_NAME "rc-loopback"
19#define RXMASK_NARROWBAND 0x1
20#define RXMASK_WIDEBAND 0x2
21
22struct loopback_dev {
23 struct rc_dev *dev;
24 u32 txmask;
25 u32 txcarrier;
26 u32 txduty;
27 bool idle;
28 bool wideband;
29 bool carrierreport;
30 u32 rxcarriermin;
31 u32 rxcarriermax;
32};
33
34static struct loopback_dev loopdev;
35
36static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
37{
38 struct loopback_dev *lodev = dev->priv;
39
40 if ((mask & (RXMASK_NARROWBAND | RXMASK_WIDEBAND)) != mask) {
41 dev_dbg(&dev->dev, "invalid tx mask: %u\n", mask);
42 return 2;
43 }
44
45 dev_dbg(&dev->dev, "setting tx mask: %u\n", mask);
46 lodev->txmask = mask;
47 return 0;
48}
49
50static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
51{
52 struct loopback_dev *lodev = dev->priv;
53
54 dev_dbg(&dev->dev, "setting tx carrier: %u\n", carrier);
55 lodev->txcarrier = carrier;
56 return 0;
57}
58
59static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
60{
61 struct loopback_dev *lodev = dev->priv;
62
63 if (duty_cycle < 1 || duty_cycle > 99) {
64 dev_dbg(&dev->dev, "invalid duty cycle: %u\n", duty_cycle);
65 return -EINVAL;
66 }
67
68 dev_dbg(&dev->dev, "setting duty cycle: %u\n", duty_cycle);
69 lodev->txduty = duty_cycle;
70 return 0;
71}
72
73static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
74{
75 struct loopback_dev *lodev = dev->priv;
76
77 if (min < 1 || min > max) {
78 dev_dbg(&dev->dev, "invalid rx carrier range %u to %u\n", min, max);
79 return -EINVAL;
80 }
81
82 dev_dbg(&dev->dev, "setting rx carrier range %u to %u\n", min, max);
83 lodev->rxcarriermin = min;
84 lodev->rxcarriermax = max;
85 return 0;
86}
87
88static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
89{
90 struct loopback_dev *lodev = dev->priv;
91 u32 rxmask;
92 unsigned i;
93 struct ir_raw_event rawir = {};
94
95 if (lodev->txcarrier < lodev->rxcarriermin ||
96 lodev->txcarrier > lodev->rxcarriermax) {
97 dev_dbg(&dev->dev, "ignoring tx, carrier out of range\n");
98 goto out;
99 }
100
101 if (lodev->wideband)
102 rxmask = RXMASK_WIDEBAND;
103 else
104 rxmask = RXMASK_NARROWBAND;
105
106 if (!(rxmask & lodev->txmask)) {
107 dev_dbg(&dev->dev, "ignoring tx, rx mask mismatch\n");
108 goto out;
109 }
110
111 for (i = 0; i < count; i++) {
112 rawir.pulse = i % 2 ? false : true;
113 rawir.duration = txbuf[i];
114
115 /* simulate overflow if ridiculously long pulse was sent */
116 if (rawir.pulse && rawir.duration > MS_TO_US(50))
117 ir_raw_event_overflow(dev);
118 else
119 ir_raw_event_store_with_filter(dev, &rawir);
120 }
121
122 if (lodev->carrierreport) {
123 rawir.pulse = false;
124 rawir.carrier_report = true;
125 rawir.carrier = lodev->txcarrier;
126
127 ir_raw_event_store(dev, &rawir);
128 }
129
130 /* Fake a silence long enough to cause us to go idle */
131 rawir.pulse = false;
132 rawir.duration = dev->timeout;
133 ir_raw_event_store_with_filter(dev, &rawir);
134
135 ir_raw_event_handle(dev);
136
137out:
138 return count;
139}
140
141static void loop_set_idle(struct rc_dev *dev, bool enable)
142{
143 struct loopback_dev *lodev = dev->priv;
144
145 if (lodev->idle != enable) {
146 dev_dbg(&dev->dev, "%sing idle mode\n", enable ? "enter" : "exit");
147 lodev->idle = enable;
148 }
149}
150
151static int loop_set_wideband_receiver(struct rc_dev *dev, int enable)
152{
153 struct loopback_dev *lodev = dev->priv;
154
155 if (lodev->wideband != enable) {
156 dev_dbg(&dev->dev, "using %sband receiver\n", enable ? "wide" : "narrow");
157 lodev->wideband = !!enable;
158 }
159
160 return 0;
161}
162
163static int loop_set_carrier_report(struct rc_dev *dev, int enable)
164{
165 struct loopback_dev *lodev = dev->priv;
166
167 if (lodev->carrierreport != enable) {
168 dev_dbg(&dev->dev, "%sabling carrier reports\n", enable ? "en" : "dis");
169 lodev->carrierreport = !!enable;
170 }
171
172 return 0;
173}
174
175static int loop_set_wakeup_filter(struct rc_dev *dev,
176 struct rc_scancode_filter *sc)
177{
178 static const unsigned int max = 512;
179 struct ir_raw_event *raw;
180 int ret;
181 int i;
182
183 /* fine to disable filter */
184 if (!sc->mask)
185 return 0;
186
187 /* encode the specified filter and loop it back */
188 raw = kmalloc_objs(*raw, max);
189 if (!raw)
190 return -ENOMEM;
191
192 ret = ir_raw_encode_scancode(dev->wakeup_protocol, sc->data, raw, max);
193 /* still loop back the partial raw IR even if it's incomplete */
194 if (ret == -ENOBUFS)
195 ret = max;
196 if (ret >= 0) {
197 /* do the loopback */
198 for (i = 0; i < ret; ++i)
199 ir_raw_event_store(dev, &raw[i]);
200 ir_raw_event_handle(dev);
201
202 ret = 0;
203 }
204
205 kfree(raw);
206
207 return ret;
208}
209
210static int __init loop_init(void)
211{
212 struct rc_dev *rc;
213 int ret;
214
215 rc = rc_allocate_device(RC_DRIVER_IR_RAW);
216 if (!rc)
217 return -ENOMEM;
218
219 rc->device_name = "rc-core loopback device";
220 rc->input_phys = "rc-core/virtual";
221 rc->input_id.bustype = BUS_VIRTUAL;
222 rc->input_id.version = 1;
223 rc->driver_name = DRIVER_NAME;
224 rc->map_name = RC_MAP_EMPTY;
225 rc->priv = &loopdev;
226 rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
227 rc->allowed_wakeup_protocols = RC_PROTO_BIT_ALL_IR_ENCODER;
228 rc->encode_wakeup = true;
229 rc->timeout = IR_DEFAULT_TIMEOUT;
230 rc->min_timeout = 1;
231 rc->max_timeout = IR_MAX_TIMEOUT;
232 rc->rx_resolution = 1;
233 rc->s_tx_mask = loop_set_tx_mask;
234 rc->s_tx_carrier = loop_set_tx_carrier;
235 rc->s_tx_duty_cycle = loop_set_tx_duty_cycle;
236 rc->s_rx_carrier_range = loop_set_rx_carrier_range;
237 rc->tx_ir = loop_tx_ir;
238 rc->s_idle = loop_set_idle;
239 rc->s_wideband_receiver = loop_set_wideband_receiver;
240 rc->s_carrier_report = loop_set_carrier_report;
241 rc->s_wakeup_filter = loop_set_wakeup_filter;
242
243 loopdev.txmask = RXMASK_NARROWBAND;
244 loopdev.txcarrier = 36000;
245 loopdev.txduty = 50;
246 loopdev.rxcarriermin = 1;
247 loopdev.rxcarriermax = ~0;
248 loopdev.idle = true;
249 loopdev.wideband = false;
250 loopdev.carrierreport = false;
251
252 ret = rc_register_device(rc);
253 if (ret < 0) {
254 dev_err(&rc->dev, "rc_dev registration failed\n");
255 rc_free_device(rc);
256 return ret;
257 }
258
259 loopdev.dev = rc;
260 return 0;
261}
262
263static void __exit loop_exit(void)
264{
265 rc_unregister_device(loopdev.dev);
266 rc_free_device(loopdev.dev);
267}
268
269module_init(loop_init);
270module_exit(loop_exit);
271
272MODULE_DESCRIPTION("Loopback device for rc-core debugging");
273MODULE_AUTHOR("David Härdeman <[email protected]>");
274MODULE_LICENSE("GPL");