summaryrefslogtreecommitdiffstats
path: root/drivers/fpga/fpga-region.c
blob: edab2a2e03ef883c9bb11b73c39fa9dc476b1329 (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
/*
 * FPGA Region - Device Tree support for FPGA programming under Linux
 *
 *  Copyright (C) 2013-2016 Altera Corporation
 *  Copyright (C) 2017 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/fpga/fpga-bridge.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/fpga/fpga-region.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

static DEFINE_IDA(fpga_region_ida);
static struct class *fpga_region_class;

struct fpga_region *fpga_region_class_find(
	struct device *start, const void *data,
	int (*match)(struct device *, const void *))
{
	struct device *dev;

	dev = class_find_device(fpga_region_class, start, data, match);
	if (!dev)
		return NULL;

	return to_fpga_region(dev);
}
EXPORT_SYMBOL_GPL(fpga_region_class_find);

/**
 * fpga_region_get - get an exclusive reference to a fpga region
 * @region: FPGA Region struct
 *
 * Caller should call fpga_region_put() when done with region.
 *
 * Return fpga_region struct if successful.
 * Return -EBUSY if someone already has a reference to the region.
 * Return -ENODEV if @np is not a FPGA Region.
 */
static struct fpga_region *fpga_region_get(struct fpga_region *region)
{
	struct device *dev = &region->dev;

	if (!mutex_trylock(&region->mutex)) {
		dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
		return ERR_PTR(-EBUSY);
	}

	get_device(dev);
	if (!try_module_get(dev->parent->driver->owner)) {
		put_device(dev);
		mutex_unlock(&region->mutex);
		return ERR_PTR(-ENODEV);
	}

	dev_dbg(dev, "get\n");

	return region;
}

/**
 * fpga_region_put - release a reference to a region
 *
 * @region: FPGA region
 */
static void fpga_region_put(struct fpga_region *region)
{
	struct device *dev = &region->dev;

	dev_dbg(dev, "put\n");

	module_put(dev->parent->driver->owner);
	put_device(dev);
	mutex_unlock(&region->mutex);
}

/**
 * fpga_region_program_fpga - program FPGA
 * @region: FPGA region
 * Program an FPGA using fpga image info (region->info).
 * Return 0 for success or negative error code.
 */
int fpga_region_program_fpga(struct fpga_region *region)
{
	struct device *dev = &region->dev;
	struct fpga_image_info *info = region->info;
	int ret;

	region = fpga_region_get(region);
	if (IS_ERR(region)) {
		dev_err(dev, "failed to get FPGA region\n");
		return PTR_ERR(region);
	}

	ret = fpga_mgr_lock(region->mgr);
	if (ret) {
		dev_err(dev, "FPGA manager is busy\n");
		goto err_put_region;
	}

	/*
	 * In some cases, we already have a list of bridges in the
	 * fpga region struct.  Or we don't have any bridges.
	 */
	if (region->get_bridges) {
		ret = region->get_bridges(region);
		if (ret) {
			dev_err(dev, "failed to get fpga region bridges\n");
			goto err_unlock_mgr;
		}
	}

	ret = fpga_bridges_disable(&region->bridge_list);
	if (ret) {
		dev_err(dev, "failed to disable bridges\n");
		goto err_put_br;
	}

	ret = fpga_mgr_load(region->mgr, info);
	if (ret) {
		dev_err(dev, "failed to load FPGA image\n");
		goto err_put_br;
	}

	ret = fpga_bridges_enable(&region->bridge_list);
	if (ret) {
		dev_err(dev, "failed to enable region bridges\n");
		goto err_put_br;
	}

	fpga_mgr_unlock(region->mgr);
	fpga_region_put(region);

	return 0;

err_put_br:
	if (region->get_bridges)
		fpga_bridges_put(&region->bridge_list);
err_unlock_mgr:
	fpga_mgr_unlock(region->mgr);
err_put_region:
	fpga_region_put(region);

	return ret;
}
EXPORT_SYMBOL_GPL(fpga_region_program_fpga);

int fpga_region_register(struct device *dev, struct fpga_region *region)
{
	int id, ret = 0;

	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
	if (id < 0)
		return id;

	mutex_init(&region->mutex);
	INIT_LIST_HEAD(&region->bridge_list);
	device_initialize(&region->dev);
	region->dev.groups = region->groups;
	region->dev.class = fpga_region_class;
	region->dev.parent = dev;
	region->dev.of_node = dev->of_node;
	region->dev.id = id;
	dev_set_drvdata(dev, region);

	ret = dev_set_name(&region->dev, "region%d", id);
	if (ret)
		goto err_remove;

	ret = device_add(&region->dev);
	if (ret)
		goto err_remove;

	return 0;

err_remove:
	ida_simple_remove(&fpga_region_ida, id);
	return ret;
}
EXPORT_SYMBOL_GPL(fpga_region_register);

int fpga_region_unregister(struct fpga_region *region)
{
	device_unregister(&region->dev);

	return 0;
}
EXPORT_SYMBOL_GPL(fpga_region_unregister);

static void fpga_region_dev_release(struct device *dev)
{
	struct fpga_region *region = to_fpga_region(dev);

	ida_simple_remove(&fpga_region_ida, region->dev.id);
}

/**
 * fpga_region_init - init function for fpga_region class
 * Creates the fpga_region class and registers a reconfig notifier.
 */
static int __init fpga_region_init(void)
{
	fpga_region_class = class_create(THIS_MODULE, "fpga_region");
	if (IS_ERR(fpga_region_class))
		return PTR_ERR(fpga_region_class);

	fpga_region_class->dev_release = fpga_region_dev_release;

	return 0;
}

static void __exit fpga_region_exit(void)
{
	class_destroy(fpga_region_class);
	ida_destroy(&fpga_region_ida);
}

subsys_initcall(fpga_region_init);
module_exit(fpga_region_exit);

MODULE_DESCRIPTION("FPGA Region");
MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
MODULE_LICENSE("GPL v2");