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1// SPDX-License-Identifier: GPL-2.0-or-later2/*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 without9 * 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 0x120#define RXMASK_WIDEBAND 0x221 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 else104 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 else119 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_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 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}267 268module_init(loop_init);269module_exit(loop_exit);270 271MODULE_DESCRIPTION("Loopback device for rc-core debugging");272MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");273MODULE_LICENSE("GPL");274