xref: /openbmc/linux/drivers/media/rc/rc-loopback.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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 <linux/slab.h>
30 #include <media/rc-core.h>
31 
32 #define DRIVER_NAME	"rc-loopback"
33 #define dprintk(x...)	if (debug) printk(KERN_INFO DRIVER_NAME ": " x)
34 #define RXMASK_REGULAR	0x1
35 #define RXMASK_LEARNING	0x2
36 
37 static bool debug;
38 
39 struct loopback_dev {
40 	struct rc_dev *dev;
41 	u32 txmask;
42 	u32 txcarrier;
43 	u32 txduty;
44 	bool idle;
45 	bool learning;
46 	bool carrierreport;
47 	u32 rxcarriermin;
48 	u32 rxcarriermax;
49 };
50 
51 static struct loopback_dev loopdev;
52 
53 static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
54 {
55 	struct loopback_dev *lodev = dev->priv;
56 
57 	if ((mask & (RXMASK_REGULAR | RXMASK_LEARNING)) != mask) {
58 		dprintk("invalid tx mask: %u\n", mask);
59 		return -EINVAL;
60 	}
61 
62 	dprintk("setting tx mask: %u\n", mask);
63 	lodev->txmask = mask;
64 	return 0;
65 }
66 
67 static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
68 {
69 	struct loopback_dev *lodev = dev->priv;
70 
71 	dprintk("setting tx carrier: %u\n", carrier);
72 	lodev->txcarrier = carrier;
73 	return 0;
74 }
75 
76 static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
77 {
78 	struct loopback_dev *lodev = dev->priv;
79 
80 	if (duty_cycle < 1 || duty_cycle > 99) {
81 		dprintk("invalid duty cycle: %u\n", duty_cycle);
82 		return -EINVAL;
83 	}
84 
85 	dprintk("setting duty cycle: %u\n", duty_cycle);
86 	lodev->txduty = duty_cycle;
87 	return 0;
88 }
89 
90 static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
91 {
92 	struct loopback_dev *lodev = dev->priv;
93 
94 	if (min < 1 || min > max) {
95 		dprintk("invalid rx carrier range %u to %u\n", min, max);
96 		return -EINVAL;
97 	}
98 
99 	dprintk("setting rx carrier range %u to %u\n", min, max);
100 	lodev->rxcarriermin = min;
101 	lodev->rxcarriermax = max;
102 	return 0;
103 }
104 
105 static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
106 {
107 	struct loopback_dev *lodev = dev->priv;
108 	u32 rxmask;
109 	unsigned i;
110 	DEFINE_IR_RAW_EVENT(rawir);
111 
112 	if (lodev->txcarrier < lodev->rxcarriermin ||
113 	    lodev->txcarrier > lodev->rxcarriermax) {
114 		dprintk("ignoring tx, carrier out of range\n");
115 		goto out;
116 	}
117 
118 	if (lodev->learning)
119 		rxmask = RXMASK_LEARNING;
120 	else
121 		rxmask = RXMASK_REGULAR;
122 
123 	if (!(rxmask & lodev->txmask)) {
124 		dprintk("ignoring tx, rx mask mismatch\n");
125 		goto out;
126 	}
127 
128 	for (i = 0; i < count; i++) {
129 		rawir.pulse = i % 2 ? false : true;
130 		rawir.duration = txbuf[i] * 1000;
131 		if (rawir.duration)
132 			ir_raw_event_store_with_filter(dev, &rawir);
133 	}
134 
135 	/* Fake a silence long enough to cause us to go idle */
136 	rawir.pulse = false;
137 	rawir.duration = dev->timeout;
138 	ir_raw_event_store_with_filter(dev, &rawir);
139 
140 	ir_raw_event_handle(dev);
141 
142 out:
143 	return count;
144 }
145 
146 static void loop_set_idle(struct rc_dev *dev, bool enable)
147 {
148 	struct loopback_dev *lodev = dev->priv;
149 
150 	if (lodev->idle != enable) {
151 		dprintk("%sing idle mode\n", enable ? "enter" : "exit");
152 		lodev->idle = enable;
153 	}
154 }
155 
156 static int loop_set_learning_mode(struct rc_dev *dev, int enable)
157 {
158 	struct loopback_dev *lodev = dev->priv;
159 
160 	if (lodev->learning != enable) {
161 		dprintk("%sing learning mode\n", enable ? "enter" : "exit");
162 		lodev->learning = !!enable;
163 	}
164 
165 	return 0;
166 }
167 
168 static int loop_set_carrier_report(struct rc_dev *dev, int enable)
169 {
170 	struct loopback_dev *lodev = dev->priv;
171 
172 	if (lodev->carrierreport != enable) {
173 		dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
174 		lodev->carrierreport = !!enable;
175 	}
176 
177 	return 0;
178 }
179 
180 static int loop_set_wakeup_filter(struct rc_dev *dev,
181 				  struct rc_scancode_filter *sc_filter)
182 {
183 	static const unsigned int max = 512;
184 	struct ir_raw_event *raw;
185 	int ret;
186 	int i;
187 
188 	/* fine to disable filter */
189 	if (!sc_filter->mask)
190 		return 0;
191 
192 	/* encode the specified filter and loop it back */
193 	raw = kmalloc_array(max, sizeof(*raw), GFP_KERNEL);
194 	ret = ir_raw_encode_scancode(dev->enabled_wakeup_protocols, sc_filter,
195 				     raw, max);
196 	/* still loop back the partial raw IR even if it's incomplete */
197 	if (ret == -ENOBUFS)
198 		ret = max;
199 	if (ret >= 0) {
200 		/* do the loopback */
201 		for (i = 0; i < ret; ++i)
202 			ir_raw_event_store(dev, &raw[i]);
203 		ir_raw_event_handle(dev);
204 
205 		ret = 0;
206 	}
207 
208 	kfree(raw);
209 
210 	return ret;
211 }
212 
213 static int __init loop_init(void)
214 {
215 	struct rc_dev *rc;
216 	int ret;
217 
218 	rc = rc_allocate_device();
219 	if (!rc) {
220 		printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
221 		return -ENOMEM;
222 	}
223 
224 	rc->input_name		= "rc-core loopback device";
225 	rc->input_phys		= "rc-core/virtual";
226 	rc->input_id.bustype	= BUS_VIRTUAL;
227 	rc->input_id.version	= 1;
228 	rc->driver_name		= DRIVER_NAME;
229 	rc->map_name		= RC_MAP_EMPTY;
230 	rc->priv		= &loopdev;
231 	rc->driver_type		= RC_DRIVER_IR_RAW;
232 	rc->encode_wakeup	= true;
233 	rc->allowed_protocols	= RC_BIT_ALL;
234 	rc->timeout		= 100 * 1000 * 1000; /* 100 ms */
235 	rc->min_timeout		= 1;
236 	rc->max_timeout		= UINT_MAX;
237 	rc->rx_resolution	= 1000;
238 	rc->tx_resolution	= 1000;
239 	rc->s_tx_mask		= loop_set_tx_mask;
240 	rc->s_tx_carrier	= loop_set_tx_carrier;
241 	rc->s_tx_duty_cycle	= loop_set_tx_duty_cycle;
242 	rc->s_rx_carrier_range	= loop_set_rx_carrier_range;
243 	rc->tx_ir		= loop_tx_ir;
244 	rc->s_idle		= loop_set_idle;
245 	rc->s_learning_mode	= loop_set_learning_mode;
246 	rc->s_carrier_report	= loop_set_carrier_report;
247 	rc->s_wakeup_filter	= loop_set_wakeup_filter;
248 
249 	loopdev.txmask		= RXMASK_REGULAR;
250 	loopdev.txcarrier	= 36000;
251 	loopdev.txduty		= 50;
252 	loopdev.rxcarriermin	= 1;
253 	loopdev.rxcarriermax	= ~0;
254 	loopdev.idle		= true;
255 	loopdev.learning	= false;
256 	loopdev.carrierreport	= false;
257 
258 	ret = rc_register_device(rc);
259 	if (ret < 0) {
260 		printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
261 		rc_free_device(rc);
262 		return ret;
263 	}
264 
265 	loopdev.dev = rc;
266 	return 0;
267 }
268 
269 static void __exit loop_exit(void)
270 {
271 	rc_unregister_device(loopdev.dev);
272 }
273 
274 module_init(loop_init);
275 module_exit(loop_exit);
276 
277 module_param(debug, bool, S_IRUGO | S_IWUSR);
278 MODULE_PARM_DESC(debug, "Enable debug messages");
279 
280 MODULE_DESCRIPTION("Loopback device for rc-core debugging");
281 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
282 MODULE_LICENSE("GPL");
283