1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Loopback driver for rc-core,
4 *
5 * Copyright (c) 2010 David Härdeman <david@hardeman.nu>
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
22 struct 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
34 static struct loopback_dev loopdev;
35
loop_set_tx_mask(struct rc_dev * dev,u32 mask)36 static 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
loop_set_tx_carrier(struct rc_dev * dev,u32 carrier)50 static 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
loop_set_tx_duty_cycle(struct rc_dev * dev,u32 duty_cycle)59 static 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
loop_set_rx_carrier_range(struct rc_dev * dev,u32 min,u32 max)73 static 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
loop_tx_ir(struct rc_dev * dev,unsigned * txbuf,unsigned count)88 static 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
137 out:
138 return count;
139 }
140
loop_set_idle(struct rc_dev * dev,bool enable)141 static 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
loop_set_wideband_receiver(struct rc_dev * dev,int enable)151 static 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
loop_set_carrier_report(struct rc_dev * dev,int enable)163 static 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
loop_set_wakeup_filter(struct rc_dev * dev,struct rc_scancode_filter * sc)175 static 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_array(max, sizeof(*raw), GFP_KERNEL);
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
loop_init(void)210 static 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->tx_resolution = 1;
234 rc->s_tx_mask = loop_set_tx_mask;
235 rc->s_tx_carrier = loop_set_tx_carrier;
236 rc->s_tx_duty_cycle = loop_set_tx_duty_cycle;
237 rc->s_rx_carrier_range = loop_set_rx_carrier_range;
238 rc->tx_ir = loop_tx_ir;
239 rc->s_idle = loop_set_idle;
240 rc->s_wideband_receiver = loop_set_wideband_receiver;
241 rc->s_carrier_report = loop_set_carrier_report;
242 rc->s_wakeup_filter = loop_set_wakeup_filter;
243
244 loopdev.txmask = RXMASK_NARROWBAND;
245 loopdev.txcarrier = 36000;
246 loopdev.txduty = 50;
247 loopdev.rxcarriermin = 1;
248 loopdev.rxcarriermax = ~0;
249 loopdev.idle = true;
250 loopdev.wideband = false;
251 loopdev.carrierreport = false;
252
253 ret = rc_register_device(rc);
254 if (ret < 0) {
255 dev_err(&rc->dev, "rc_dev registration failed\n");
256 rc_free_device(rc);
257 return ret;
258 }
259
260 loopdev.dev = rc;
261 return 0;
262 }
263
loop_exit(void)264 static void __exit loop_exit(void)
265 {
266 rc_unregister_device(loopdev.dev);
267 }
268
269 module_init(loop_init);
270 module_exit(loop_exit);
271
272 MODULE_DESCRIPTION("Loopback device for rc-core debugging");
273 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
274 MODULE_LICENSE("GPL");
275