aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/input/pid.c
blob: a00672c96644a06452cf513f3026697998be7dc2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 *  PID Force feedback support for hid devices.
 *
 *  Copyright (c) 2002 Rodrigo Damazio.
 *  Portions by Johann Deneux and Bjorn Augustson
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so by
 * e-mail - mail your message to <rdamazio@lsi.usp.br>
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/input.h>
#include <linux/usb.h>
#include "hid.h"
#include "pid.h"

#define DEBUG

#define CHECK_OWNERSHIP(i, hid_pid)	\
	((i) < FF_EFFECTS_MAX && i >= 0 && \
	test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \
	(current->pid == 0 || \
	(hid_pid)->effects[(i)].owner == current->pid))

/* Called when a transfer is completed */
static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs)
{
	dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n");
}

static void hid_pid_exit(struct hid_device *hid)
{
	struct hid_ff_pid *private = hid->ff_private;

	if (private->urbffout) {
		usb_kill_urb(private->urbffout);
		usb_free_urb(private->urbffout);
	}
}

static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
	dev_info(&pid->hid->dev->dev, "requested periodic force upload\n");
	return 0;
}

static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
	dev_info(&pid->hid->dev->dev, "requested constant force upload\n");
	return 0;
}

static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
	dev_info(&pid->hid->dev->dev, "requested Condition force upload\n");
	return 0;
}

static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update)
{
	dev_info(&pid->hid->dev->dev, "request ramp force upload\n");
	return 0;
}

static int hid_pid_event(struct hid_device *hid, struct input_dev *input,
			 unsigned int type, unsigned int code, int value)
{
	dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value);

	if (type != EV_FF)
		return -1;

	return 0;
}

/* Lock must be held by caller */
static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play)
{
	if (play)
		set_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
	else
		clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags);
}

static int hid_pid_erase(struct input_dev *dev, int id)
{
	struct hid_device *hid = dev->private;
	struct hid_ff_pid *pid = hid->ff_private;
	struct hid_field *field;
	unsigned long flags;
	int ret;

	if (!CHECK_OWNERSHIP(id, pid))
		return -EACCES;

	/* Find report */
	field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE,
					HID_OUTPUT_REPORT);
	if (!field) {
		dev_err(&hid->dev->dev, "couldn't find report\n");
		return -EIO;
	}

	ret = hid_set_field(field, 0, pid->effects[id].device_id);
	if (ret) {
		dev_err(&hid->dev->dev, "couldn't set field\n");
		return ret;
	}

	hid_submit_report(hid, field->report, USB_DIR_OUT);

	spin_lock_irqsave(&pid->lock, flags);
	hid_pid_ctrl_playback(hid, pid->effects + id, 0);
	pid->effects[id].flags = 0;
	spin_unlock_irqrestore(&pid->lock, flags);

	return 0;
}

/* Erase all effects this process owns */
static int hid_pid_flush(struct input_dev *dev, struct file *file)
{
	struct hid_device *hid = dev->private;
	struct hid_ff_pid *pid = hid->ff_private;
	int i;

	/*NOTE: no need to lock here. The only times EFFECT_USED is
	   modified is when effects are uploaded or when an effect is
	   erased. But a process cannot close its dev/input/eventX fd
	   and perform ioctls on the same fd all at the same time */
	/*FIXME: multiple threads, anyone? */
	for (i = 0; i < dev->ff_effects_max; ++i)
		if (current->pid == pid->effects[i].owner
		    && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags))
			if (hid_pid_erase(dev, i))
				dev_warn(&hid->dev->dev, "erase effect %d failed", i);

	return 0;
}

static int hid_pid_upload_effect(struct input_dev *dev,
				 struct ff_effect *effect)
{
	struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private);
	int ret;
	int is_update;
	unsigned long flags;

	dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type);
	/* Check this effect type is supported by this device */
	if (!test_bit(effect->type, dev->ffbit)) {
		dev_dbg(&pid_private->hid->dev->dev,
			"invalid kind of effect requested.\n");
		return -EINVAL;
	}

	/*
	 * If we want to create a new effect, get a free id
	 */
	if (effect->id == -1) {
		int id = 0;

		// Spinlock so we don`t get a race condition when choosing IDs
		spin_lock_irqsave(&pid_private->lock, flags);

		while (id < FF_EFFECTS_MAX)
			if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags))
				break;

		if (id == FF_EFFECTS_MAX) {
			spin_unlock_irqrestore(&pid_private->lock, flags);
// TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) {
			dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n");
			return -ENOMEM;
		}

		effect->id = id;
		dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d\n.", id);
		pid_private->effects[id].owner = current->pid;
		pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED);
		spin_unlock_irqrestore(&pid_private->lock, flags);

		is_update = FF_PID_FALSE;
	} else {
		/* We want to update an effect */
		if (!CHECK_OWNERSHIP(effect->id, pid_private))
			return -EACCES;

		/* Parameter type cannot be updated */
		if (effect->type != pid_private->effects[effect->id].effect.type)
			return -EINVAL;

		/* Check the effect is not already being updated */
		if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags))
			return -EAGAIN;

		is_update = FF_PID_TRUE;
	}

	/*
	 * Upload the effect
	 */
	switch (effect->type) {
	case FF_PERIODIC:
		ret = pid_upload_periodic(pid_private, effect, is_update);
		break;

	case FF_CONSTANT:
		ret = pid_upload_constant(pid_private, effect, is_update);
		break;

	case FF_SPRING:
	case FF_FRICTION:
	case FF_DAMPER:
	case FF_INERTIA:
		ret = pid_upload_condition(pid_private, effect, is_update);
		break;

	case FF_RAMP:
		ret = pid_upload_ramp(pid_private, effect, is_update);
		break;

	default:
		dev_dbg(&pid_private->hid->dev->dev,
			"invalid type of effect requested - %x.\n",
			effect->type);
		return -EINVAL;
	}
	/* If a packet was sent, forbid new updates until we are notified
	 * that the packet was updated
	 */
	if (ret == 0)
		set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags);
	pid_private->effects[effect->id].effect = *effect;
	return ret;
}

int hid_pid_init(struct hid_device *hid)
{
	struct hid_ff_pid *private;
	struct hid_input *hidinput = list_entry(&hid->inputs, struct hid_input, list);
	struct input_dev *input_dev = hidinput->input;

	private = hid->ff_private = kzalloc(sizeof(struct hid_ff_pid), GFP_KERNEL);
	if (!private)
		return -ENOMEM;

	private->hid = hid;

	hid->ff_exit = hid_pid_exit;
	hid->ff_event = hid_pid_event;

	/* Open output URB */
	if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) {
		kfree(private);
		return -1;
	}

	usb_fill_control_urb(private->urbffout, hid->dev, 0,
			     (void *)&private->ffcr, private->ctrl_buffer, 8,
			     hid_pid_ctrl_out, hid);

	input_dev->upload_effect = hid_pid_upload_effect;
	input_dev->flush = hid_pid_flush;
	input_dev->ff_effects_max = 8;	// A random default
	set_bit(EV_FF, input_dev->evbit);
	set_bit(EV_FF_STATUS, input_dev->evbit);

	spin_lock_init(&private->lock);

	printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n");

	return 0;
}