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 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 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 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 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 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 } 140 141 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 } 150 151 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 } 162 163 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 } 174 175 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 } 209 210 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 } 263 264 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