1/*
2 * Loopback driver for rc-core,
3 *
4 * Copyright (c) 2010 David Härdeman <david@hardeman.nu>
5 *
6 * This driver receives TX data and passes it back as RX data,
7 * which is useful for (scripted) debugging of rc-core without
8 * having to use actual hardware.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25
26#include <linux/device.h>
27#include <linux/module.h>
28#include <linux/sched.h>
29#include <media/rc-core.h>
30
31#define DRIVER_NAME	"rc-loopback"
32#define dprintk(x...)	if (debug) printk(KERN_INFO DRIVER_NAME ": " x)
33#define RXMASK_REGULAR	0x1
34#define RXMASK_LEARNING	0x2
35
36static bool debug;
37
38struct loopback_dev {
39	struct rc_dev *dev;
40	u32 txmask;
41	u32 txcarrier;
42	u32 txduty;
43	bool idle;
44	bool learning;
45	bool carrierreport;
46	u32 rxcarriermin;
47	u32 rxcarriermax;
48};
49
50static struct loopback_dev loopdev;
51
52static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
53{
54	struct loopback_dev *lodev = dev->priv;
55
56	if ((mask & (RXMASK_REGULAR | RXMASK_LEARNING)) != mask) {
57		dprintk("invalid tx mask: %u\n", mask);
58		return -EINVAL;
59	}
60
61	dprintk("setting tx mask: %u\n", mask);
62	lodev->txmask = mask;
63	return 0;
64}
65
66static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
67{
68	struct loopback_dev *lodev = dev->priv;
69
70	dprintk("setting tx carrier: %u\n", carrier);
71	lodev->txcarrier = carrier;
72	return 0;
73}
74
75static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
76{
77	struct loopback_dev *lodev = dev->priv;
78
79	if (duty_cycle < 1 || duty_cycle > 99) {
80		dprintk("invalid duty cycle: %u\n", duty_cycle);
81		return -EINVAL;
82	}
83
84	dprintk("setting duty cycle: %u\n", duty_cycle);
85	lodev->txduty = duty_cycle;
86	return 0;
87}
88
89static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
90{
91	struct loopback_dev *lodev = dev->priv;
92
93	if (min < 1 || min > max) {
94		dprintk("invalid rx carrier range %u to %u\n", min, max);
95		return -EINVAL;
96	}
97
98	dprintk("setting rx carrier range %u to %u\n", min, max);
99	lodev->rxcarriermin = min;
100	lodev->rxcarriermax = max;
101	return 0;
102}
103
104static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
105{
106	struct loopback_dev *lodev = dev->priv;
107	u32 rxmask;
108	unsigned total_duration = 0;
109	unsigned i;
110	DEFINE_IR_RAW_EVENT(rawir);
111
112	for (i = 0; i < count; i++)
113		total_duration += abs(txbuf[i]);
114
115	if (total_duration == 0) {
116		dprintk("invalid tx data, total duration zero\n");
117		return -EINVAL;
118	}
119
120	if (lodev->txcarrier < lodev->rxcarriermin ||
121	    lodev->txcarrier > lodev->rxcarriermax) {
122		dprintk("ignoring tx, carrier out of range\n");
123		goto out;
124	}
125
126	if (lodev->learning)
127		rxmask = RXMASK_LEARNING;
128	else
129		rxmask = RXMASK_REGULAR;
130
131	if (!(rxmask & lodev->txmask)) {
132		dprintk("ignoring tx, rx mask mismatch\n");
133		goto out;
134	}
135
136	for (i = 0; i < count; i++) {
137		rawir.pulse = i % 2 ? false : true;
138		rawir.duration = txbuf[i] * 1000;
139		if (rawir.duration)
140			ir_raw_event_store_with_filter(dev, &rawir);
141	}
142
143	/* Fake a silence long enough to cause us to go idle */
144	rawir.pulse = false;
145	rawir.duration = dev->timeout;
146	ir_raw_event_store_with_filter(dev, &rawir);
147
148	ir_raw_event_handle(dev);
149
150out:
151	/* Lirc expects this function to take as long as the total duration */
152	set_current_state(TASK_INTERRUPTIBLE);
153	schedule_timeout(usecs_to_jiffies(total_duration));
154	return count;
155}
156
157static void loop_set_idle(struct rc_dev *dev, bool enable)
158{
159	struct loopback_dev *lodev = dev->priv;
160
161	if (lodev->idle != enable) {
162		dprintk("%sing idle mode\n", enable ? "enter" : "exit");
163		lodev->idle = enable;
164	}
165}
166
167static int loop_set_learning_mode(struct rc_dev *dev, int enable)
168{
169	struct loopback_dev *lodev = dev->priv;
170
171	if (lodev->learning != enable) {
172		dprintk("%sing learning mode\n", enable ? "enter" : "exit");
173		lodev->learning = !!enable;
174	}
175
176	return 0;
177}
178
179static int loop_set_carrier_report(struct rc_dev *dev, int enable)
180{
181	struct loopback_dev *lodev = dev->priv;
182
183	if (lodev->carrierreport != enable) {
184		dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
185		lodev->carrierreport = !!enable;
186	}
187
188	return 0;
189}
190
191static int __init loop_init(void)
192{
193	struct rc_dev *rc;
194	int ret;
195
196	rc = rc_allocate_device();
197	if (!rc) {
198		printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
199		return -ENOMEM;
200	}
201
202	rc->input_name		= "rc-core loopback device";
203	rc->input_phys		= "rc-core/virtual";
204	rc->input_id.bustype	= BUS_VIRTUAL;
205	rc->input_id.version	= 1;
206	rc->driver_name		= DRIVER_NAME;
207	rc->map_name		= RC_MAP_EMPTY;
208	rc->priv		= &loopdev;
209	rc->driver_type		= RC_DRIVER_IR_RAW;
210	rc->allowed_protos	= RC_TYPE_ALL;
211	rc->timeout		= 100 * 1000 * 1000; /* 100 ms */
212	rc->min_timeout		= 1;
213	rc->max_timeout		= UINT_MAX;
214	rc->rx_resolution	= 1000;
215	rc->tx_resolution	= 1000;
216	rc->s_tx_mask		= loop_set_tx_mask;
217	rc->s_tx_carrier	= loop_set_tx_carrier;
218	rc->s_tx_duty_cycle	= loop_set_tx_duty_cycle;
219	rc->s_rx_carrier_range	= loop_set_rx_carrier_range;
220	rc->tx_ir		= loop_tx_ir;
221	rc->s_idle		= loop_set_idle;
222	rc->s_learning_mode	= loop_set_learning_mode;
223	rc->s_carrier_report	= loop_set_carrier_report;
224	rc->priv		= &loopdev;
225
226	loopdev.txmask		= RXMASK_REGULAR;
227	loopdev.txcarrier	= 36000;
228	loopdev.txduty		= 50;
229	loopdev.rxcarriermin	= 1;
230	loopdev.rxcarriermax	= ~0;
231	loopdev.idle		= true;
232	loopdev.learning	= false;
233	loopdev.carrierreport	= false;
234
235	ret = rc_register_device(rc);
236	if (ret < 0) {
237		printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
238		rc_free_device(rc);
239		return ret;
240	}
241
242	loopdev.dev = rc;
243	return 0;
244}
245
246static void __exit loop_exit(void)
247{
248	rc_unregister_device(loopdev.dev);
249}
250
251module_init(loop_init);
252module_exit(loop_exit);
253
254module_param(debug, bool, S_IRUGO | S_IWUSR);
255MODULE_PARM_DESC(debug, "Enable debug messages");
256
257MODULE_DESCRIPTION("Loopback device for rc-core debugging");
258MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
259MODULE_LICENSE("GPL");
260