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
|
// SPDX-License-Identifier: GPL-2.0
/*
* FPGA to SDRAM Bridge Driver for Altera SoCFPGA Devices
*
* Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
*/
/*
* This driver manages a bridge between an FPGA and the SDRAM used by the ARM
* host processor system (HPS).
*
* The bridge contains 4 read ports, 4 write ports, and 6 command ports.
* Reconfiguring these ports requires that no SDRAM transactions occur during
* reconfiguration. The code reconfiguring the ports cannot run out of SDRAM
* nor can the FPGA access the SDRAM during reconfiguration. This driver does
* not support reconfiguring the ports. The ports are configured by code
* running out of on chip ram before Linux is started and the configuration
* is passed in a handoff register in the system manager.
*
* 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/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>
#define ALT_SDR_CTL_FPGAPORTRST_OFST 0x80
#define ALT_SDR_CTL_FPGAPORTRST_PORTRSTN_MSK 0x00003fff
#define ALT_SDR_CTL_FPGAPORTRST_RD_SHIFT 0
#define ALT_SDR_CTL_FPGAPORTRST_WR_SHIFT 4
#define ALT_SDR_CTL_FPGAPORTRST_CTRL_SHIFT 8
/*
* From the Cyclone V HPS Memory Map document:
* These registers are used to store handoff information between the
* preloader and the OS. These 8 registers can be used to store any
* information. The contents of these registers have no impact on
* the state of the HPS hardware.
*/
#define SYSMGR_ISWGRP_HANDOFF3 (0x8C)
#define F2S_BRIDGE_NAME "fpga2sdram"
struct alt_fpga2sdram_data {
struct device *dev;
struct regmap *sdrctl;
int mask;
};
static int alt_fpga2sdram_enable_show(struct fpga_bridge *bridge)
{
struct alt_fpga2sdram_data *priv = bridge->priv;
int value;
regmap_read(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST, &value);
return (value & priv->mask) == priv->mask;
}
static inline int _alt_fpga2sdram_enable_set(struct alt_fpga2sdram_data *priv,
bool enable)
{
return regmap_update_bits(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST,
priv->mask, enable ? priv->mask : 0);
}
static int alt_fpga2sdram_enable_set(struct fpga_bridge *bridge, bool enable)
{
return _alt_fpga2sdram_enable_set(bridge->priv, enable);
}
struct prop_map {
char *prop_name;
u32 *prop_value;
u32 prop_max;
};
static const struct fpga_bridge_ops altera_fpga2sdram_br_ops = {
.enable_set = alt_fpga2sdram_enable_set,
.enable_show = alt_fpga2sdram_enable_show,
};
static const struct of_device_id altera_fpga_of_match[] = {
{ .compatible = "altr,socfpga-fpga2sdram-bridge" },
{},
};
static int alt_fpga_bridge_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct alt_fpga2sdram_data *priv;
struct fpga_bridge *br;
u32 enable;
struct regmap *sysmgr;
int ret = 0;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
priv->sdrctl = syscon_regmap_lookup_by_compatible("altr,sdr-ctl");
if (IS_ERR(priv->sdrctl)) {
dev_err(dev, "regmap for altr,sdr-ctl lookup failed.\n");
return PTR_ERR(priv->sdrctl);
}
sysmgr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
if (IS_ERR(sysmgr)) {
dev_err(dev, "regmap for altr,sys-mgr lookup failed.\n");
return PTR_ERR(sysmgr);
}
/* Get f2s bridge configuration saved in handoff register */
regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
&altera_fpga2sdram_br_ops, priv);
if (IS_ERR(br))
return PTR_ERR(br);
platform_set_drvdata(pdev, br);
dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
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_fpga2sdram_enable_set(priv, enable);
if (ret) {
fpga_bridge_unregister(br);
return ret;
}
}
}
return ret;
}
static int alt_fpga_bridge_remove(struct platform_device *pdev)
{
struct fpga_bridge *br = platform_get_drvdata(pdev);
fpga_bridge_unregister(br);
return 0;
}
MODULE_DEVICE_TABLE(of, altera_fpga_of_match);
static struct platform_driver altera_fpga_driver = {
.probe = alt_fpga_bridge_probe,
.remove = alt_fpga_bridge_remove,
.driver = {
.name = "altera_fpga2sdram_bridge",
.of_match_table = of_match_ptr(altera_fpga_of_match),
},
};
module_platform_driver(altera_fpga_driver);
MODULE_DESCRIPTION("Altera SoCFPGA FPGA to SDRAM Bridge");
MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
MODULE_LICENSE("GPL v2");
|
