summaryrefslogtreecommitdiffstats
path: root/drivers/fpga/xilinx-pr-decoupler.c
blob: 6410361352079717f123ee6f6b1a52f15d39b12e (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
/*
 * Copyright (c) 2017, National Instruments Corp.
 * Copyright (c) 2017, Xilix Inc
 *
 * FPGA Bridge Driver for the Xilinx LogiCORE Partial Reconfiguration
 * Decoupler IP Core.
 *
 * 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; version 2 of the License.
 *
 * 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.
 */

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/fpga/fpga-bridge.h>

#define CTRL_CMD_DECOUPLE	BIT(0)
#define CTRL_CMD_COUPLE		0
#define CTRL_OFFSET		0

struct xlnx_pr_decoupler_data {
	void __iomem *io_base;
	struct clk *clk;
};

static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,
					   u32 offset, u32 val)
{
	writel(val, d->io_base + offset);
}

static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,
					u32 offset)
{
	return readl(d->io_base + offset);
}

static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)
{
	int err;
	struct xlnx_pr_decoupler_data *priv = bridge->priv;

	err = clk_enable(priv->clk);
	if (err)
		return err;

	if (enable)
		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);
	else
		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);

	clk_disable(priv->clk);

	return 0;
}

static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)
{
	const struct xlnx_pr_decoupler_data *priv = bridge->priv;
	u32 status;
	int err;

	err = clk_enable(priv->clk);
	if (err)
		return err;

	status = readl(priv->io_base);

	clk_disable(priv->clk);

	return !status;
}

static const struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {
	.enable_set = xlnx_pr_decoupler_enable_set,
	.enable_show = xlnx_pr_decoupler_enable_show,
};

static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
	{ .compatible = "xlnx,pr-decoupler-1.00", },
	{ .compatible = "xlnx,pr-decoupler", },
	{},
};
MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);

static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
{
	struct xlnx_pr_decoupler_data *priv;
	struct fpga_bridge *br;
	int err;
	struct resource *res;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->io_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(priv->io_base))
		return PTR_ERR(priv->io_base);

	priv->clk = devm_clk_get(&pdev->dev, "aclk");
	if (IS_ERR(priv->clk)) {
		dev_err(&pdev->dev, "input clock not found\n");
		return PTR_ERR(priv->clk);
	}

	err = clk_prepare_enable(priv->clk);
	if (err) {
		dev_err(&pdev->dev, "unable to enable clock\n");
		return err;
	}

	clk_disable(priv->clk);

	br = devm_fpga_bridge_create(&pdev->dev, "Xilinx PR Decoupler",
				     &xlnx_pr_decoupler_br_ops, priv);
	if (!br) {
		err = -ENOMEM;
		goto err_clk;
	}

	platform_set_drvdata(pdev, br);

	err = fpga_bridge_register(br);
	if (err) {
		dev_err(&pdev->dev, "unable to register Xilinx PR Decoupler");
		goto err_clk;
	}

	return 0;

err_clk:
	clk_unprepare(priv->clk);

	return err;
}

static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
{
	struct fpga_bridge *bridge = platform_get_drvdata(pdev);
	struct xlnx_pr_decoupler_data *p = bridge->priv;

	fpga_bridge_unregister(bridge);

	clk_unprepare(p->clk);

	return 0;
}

static struct platform_driver xlnx_pr_decoupler_driver = {
	.probe = xlnx_pr_decoupler_probe,
	.remove = xlnx_pr_decoupler_remove,
	.driver = {
		.name = "xlnx_pr_decoupler",
		.of_match_table = of_match_ptr(xlnx_pr_decoupler_of_match),
	},
};

module_platform_driver(xlnx_pr_decoupler_driver);

MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
MODULE_LICENSE("GPL v2");