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 i;
109	DEFINE_IR_RAW_EVENT(rawir);
110
111	if (lodev->txcarrier < lodev->rxcarriermin ||
112	    lodev->txcarrier > lodev->rxcarriermax) {
113		dprintk("ignoring tx, carrier out of range\n");
114		goto out;
115	}
116
117	if (lodev->learning)
118		rxmask = RXMASK_LEARNING;
119	else
120		rxmask = RXMASK_REGULAR;
121
122	if (!(rxmask & lodev->txmask)) {
123		dprintk("ignoring tx, rx mask mismatch\n");
124		goto out;
125	}
126
127	for (i = 0; i < count; i++) {
128		rawir.pulse = i % 2 ? false : true;
129		rawir.duration = txbuf[i] * 1000;
130		if (rawir.duration)
131			ir_raw_event_store_with_filter(dev, &rawir);
132	}
133
134	/* Fake a silence long enough to cause us to go idle */
135	rawir.pulse = false;
136	rawir.duration = dev->timeout;
137	ir_raw_event_store_with_filter(dev, &rawir);
138
139	ir_raw_event_handle(dev);
140
141out:
142	return count;
143}
144
145static void loop_set_idle(struct rc_dev *dev, bool enable)
146{
147	struct loopback_dev *lodev = dev->priv;
148
149	if (lodev->idle != enable) {
150		dprintk("%sing idle mode\n", enable ? "enter" : "exit");
151		lodev->idle = enable;
152	}
153}
154
155static int loop_set_learning_mode(struct rc_dev *dev, int enable)
156{
157	struct loopback_dev *lodev = dev->priv;
158
159	if (lodev->learning != enable) {
160		dprintk("%sing learning mode\n", enable ? "enter" : "exit");
161		lodev->learning = !!enable;
162	}
163
164	return 0;
165}
166
167static int loop_set_carrier_report(struct rc_dev *dev, int enable)
168{
169	struct loopback_dev *lodev = dev->priv;
170
171	if (lodev->carrierreport != enable) {
172		dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
173		lodev->carrierreport = !!enable;
174	}
175
176	return 0;
177}
178
179static int __init loop_init(void)
180{
181	struct rc_dev *rc;
182	int ret;
183
184	rc = rc_allocate_device();
185	if (!rc) {
186		printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
187		return -ENOMEM;
188	}
189
190	rc->input_name		= "rc-core loopback device";
191	rc->input_phys		= "rc-core/virtual";
192	rc->input_id.bustype	= BUS_VIRTUAL;
193	rc->input_id.version	= 1;
194	rc->driver_name		= DRIVER_NAME;
195	rc->map_name		= RC_MAP_EMPTY;
196	rc->priv		= &loopdev;
197	rc->driver_type		= RC_DRIVER_IR_RAW;
198	rc->allowed_protocols	= RC_BIT_ALL;
199	rc->timeout		= 100 * 1000 * 1000; /* 100 ms */
200	rc->min_timeout		= 1;
201	rc->max_timeout		= UINT_MAX;
202	rc->rx_resolution	= 1000;
203	rc->tx_resolution	= 1000;
204	rc->s_tx_mask		= loop_set_tx_mask;
205	rc->s_tx_carrier	= loop_set_tx_carrier;
206	rc->s_tx_duty_cycle	= loop_set_tx_duty_cycle;
207	rc->s_rx_carrier_range	= loop_set_rx_carrier_range;
208	rc->tx_ir		= loop_tx_ir;
209	rc->s_idle		= loop_set_idle;
210	rc->s_learning_mode	= loop_set_learning_mode;
211	rc->s_carrier_report	= loop_set_carrier_report;
212
213	loopdev.txmask		= RXMASK_REGULAR;
214	loopdev.txcarrier	= 36000;
215	loopdev.txduty		= 50;
216	loopdev.rxcarriermin	= 1;
217	loopdev.rxcarriermax	= ~0;
218	loopdev.idle		= true;
219	loopdev.learning	= false;
220	loopdev.carrierreport	= false;
221
222	ret = rc_register_device(rc);
223	if (ret < 0) {
224		printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
225		rc_free_device(rc);
226		return ret;
227	}
228
229	loopdev.dev = rc;
230	return 0;
231}
232
233static void __exit loop_exit(void)
234{
235	rc_unregister_device(loopdev.dev);
236}
237
238module_init(loop_init);
239module_exit(loop_exit);
240
241module_param(debug, bool, S_IRUGO | S_IWUSR);
242MODULE_PARM_DESC(debug, "Enable debug messages");
243
244MODULE_DESCRIPTION("Loopback device for rc-core debugging");
245MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
246MODULE_LICENSE("GPL");
247