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
|
// SPDX-License-Identifier: GPL-2.0
/*
* FPGA to/from HPS Bridge Driver for Altera SoCFPGA Devices
*
* Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
*
* Includes this patch from the mailing list:
* fpga: altera-hps2fpga: fix HPS2FPGA bridge visibility to L3 masters
* Signed-off-by: Anatolij Gustschin <agust@denx.de>
*/
/*
* This driver manages bridges on a Altera SOCFPGA between the ARM host
* processor system (HPS) and the embedded FPGA.
*
* This driver supports enabling and disabling of the configured ports, which
* allows for safe reprogramming of the FPGA, assuming that the new FPGA image
* uses the same port configuration. Bridges must be disabled before
* reprogramming the FPGA and re-enabled after the FPGA has been programmed.
*/
#include <linux/clk.h>
#include <linux/fpga/fpga-bridge.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/spinlock.h>
#define ALT_L3_REMAP_OFST 0x0
#define ALT_L3_REMAP_MPUZERO_MSK 0x00000001
#define ALT_L3_REMAP_H2F_MSK 0x00000008
#define ALT_L3_REMAP_LWH2F_MSK 0x00000010
#define HPS2FPGA_BRIDGE_NAME "hps2fpga"
#define LWHPS2FPGA_BRIDGE_NAME "lwhps2fpga"
#define FPGA2HPS_BRIDGE_NAME "fpga2hps"
struct altera_hps2fpga_data {
const char *name;
struct reset_control *bridge_reset;
struct regmap *l3reg;
unsigned int remap_mask;
struct clk *clk;
};
static int alt_hps2fpga_enable_show(struct fpga_bridge *bridge)
{
struct altera_hps2fpga_data *priv = bridge->priv;
return reset_control_status(priv->bridge_reset);
}
/* The L3 REMAP register is write only, so keep a cached value. */
static unsigned int l3_remap_shadow;
static DEFINE_SPINLOCK(l3_remap_lock);
static int _alt_hps2fpga_enable_set(struct altera_hps2fpga_data *priv,
bool enable)
{
unsigned long flags;
int ret;
/* bring bridge out of reset */
if (enable)
ret = reset_control_deassert(priv->bridge_reset);
else
ret = reset_control_assert(priv->bridge_reset);
if (ret)
return ret;
/* Allow bridge to be visible to L3 masters or not */
if (priv->remap_mask) {
spin_lock_irqsave(&l3_remap_lock, flags);
l3_remap_shadow |= ALT_L3_REMAP_MPUZERO_MSK;
if (enable)
l3_remap_shadow |= priv->remap_mask;
else
l3_remap_shadow &= ~priv->remap_mask;
ret = regmap_write(priv->l3reg, ALT_L3_REMAP_OFST,
l3_remap_shadow);
spin_unlock_irqrestore(&l3_remap_lock, flags);
}
return ret;
}
static int alt_hps2fpga_enable_set(struct fpga_bridge *bridge, bool enable)
{
return _alt_hps2fpga_enable_set(bridge->priv, enable);
}
static const struct fpga_bridge_ops altera_hps2fpga_br_ops = {
.enable_set = alt_hps2fpga_enable_set,
.enable_show = alt_hps2fpga_enable_show,
};
static struct altera_hps2fpga_data hps2fpga_data = {
.name = HPS2FPGA_BRIDGE_NAME,
.remap_mask = ALT_L3_REMAP_H2F_MSK,
};
static struct altera_hps2fpga_data lwhps2fpga_data = {
.name = LWHPS2FPGA_BRIDGE_NAME,
.remap_mask = ALT_L3_REMAP_LWH2F_MSK,
};
static struct altera_hps2fpga_data fpga2hps_data = {
.name = FPGA2HPS_BRIDGE_NAME,
};
static const struct of_device_id altera_fpga_of_match[] = {
{ .compatible = "altr,socfpga-hps2fpga-bridge",
.data = &hps2fpga_data },
{ .compatible = "altr,socfpga-lwhps2fpga-bridge",
.data = &lwhps2fpga_data },
{ .compatible = "altr,socfpga-fpga2hps-bridge",
.data = &fpga2hps_data },
{},
};
static int alt_fpga_bridge_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct altera_hps2fpga_data *priv;
const struct of_device_id *of_id;
struct fpga_bridge *br;
u32 enable;
int ret;
of_id = of_match_device(altera_fpga_of_match, dev);
if (!of_id) {
dev_err(dev, "failed to match device\n");
return -ENODEV;
}
priv = (struct altera_hps2fpga_data *)of_id->data;
priv->bridge_reset = of_reset_control_get_exclusive_by_index(dev->of_node,
0);
if (IS_ERR(priv->bridge_reset)) {
dev_err(dev, "Could not get %s reset control\n", priv->name);
return PTR_ERR(priv->bridge_reset);
}
if (priv->remap_mask) {
priv->l3reg = syscon_regmap_lookup_by_compatible("altr,l3regs");
if (IS_ERR(priv->l3reg)) {
dev_err(dev, "regmap for altr,l3regs lookup failed\n");
return PTR_ERR(priv->l3reg);
}
}
priv->clk = devm_clk_get(dev, NULL);
if (IS_ERR(priv->clk)) {
dev_err(dev, "no clock specified\n");
return PTR_ERR(priv->clk);
}
ret = clk_prepare_enable(priv->clk);
if (ret) {
dev_err(dev, "could not enable clock\n");
return -EBUSY;
}
if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
if (enable > 1) {
dev_warn(dev, "invalid bridge-enable %u > 1\n", enable);
} else {
dev_info(dev, "%s bridge\n",
(enable ? "enabling" : "disabling"));
ret = _alt_hps2fpga_enable_set(priv, enable);
if (ret)
goto err;
}
}
br = fpga_bridge_create(dev, priv->name, &altera_hps2fpga_br_ops, priv);
if (!br) {
ret = -ENOMEM;
goto err;
}
platform_set_drvdata(pdev, br);
ret = fpga_bridge_register(br);
if (ret)
goto err_free;
return 0;
err_free:
fpga_bridge_free(br);
err:
clk_disable_unprepare(priv->clk);
return ret;
}
static int alt_fpga_bridge_remove(struct platform_device *pdev)
{
struct fpga_bridge *bridge = platform_get_drvdata(pdev);
struct altera_hps2fpga_data *priv = bridge->priv;
fpga_bridge_unregister(bridge);
clk_disable_unprepare(priv->clk);
return 0;
}
MODULE_DEVICE_TABLE(of, altera_fpga_of_match);
static struct platform_driver alt_fpga_bridge_driver = {
.probe = alt_fpga_bridge_probe,
.remove = alt_fpga_bridge_remove,
.driver = {
.name = "altera_hps2fpga_bridge",
.of_match_table = of_match_ptr(altera_fpga_of_match),
},
};
module_platform_driver(alt_fpga_bridge_driver);
MODULE_DESCRIPTION("Altera SoCFPGA HPS to FPGA Bridge");
MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
MODULE_LICENSE("GPL v2");
|
