1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2017, National Instruments Corp.
4 * Copyright (c) 2017, Xilinx Inc
5 *
6 * FPGA Bridge Driver for the Xilinx LogiCORE Partial Reconfiguration
7 * Decoupler IP Core.
8 */
9
10#include <linux/clk.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/property.h>
17#include <linux/fpga/fpga-bridge.h>
18
19#define CTRL_CMD_DECOUPLE	BIT(0)
20#define CTRL_CMD_COUPLE		0
21#define CTRL_OFFSET		0
22
23struct xlnx_config_data {
24	const char *name;
25};
26
27struct xlnx_pr_decoupler_data {
28	const struct xlnx_config_data *ipconfig;
29	void __iomem *io_base;
30	struct clk *clk;
31};
32
33static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,
34					   u32 offset, u32 val)
35{
36	writel(val, d->io_base + offset);
37}
38
39static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,
40					u32 offset)
41{
42	return readl(d->io_base + offset);
43}
44
45static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)
46{
47	int err;
48	struct xlnx_pr_decoupler_data *priv = bridge->priv;
49
50	err = clk_enable(priv->clk);
51	if (err)
52		return err;
53
54	if (enable)
55		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);
56	else
57		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);
58
59	clk_disable(priv->clk);
60
61	return 0;
62}
63
64static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)
65{
66	const struct xlnx_pr_decoupler_data *priv = bridge->priv;
67	u32 status;
68	int err;
69
70	err = clk_enable(priv->clk);
71	if (err)
72		return err;
73
74	status = xlnx_pr_decouple_read(priv, CTRL_OFFSET);
75
76	clk_disable(priv->clk);
77
78	return !status;
79}
80
81static const struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {
82	.enable_set = xlnx_pr_decoupler_enable_set,
83	.enable_show = xlnx_pr_decoupler_enable_show,
84};
85
86static const struct xlnx_config_data decoupler_config = {
87	.name = "Xilinx PR Decoupler",
88};
89
90static const struct xlnx_config_data shutdown_config = {
91	.name = "Xilinx DFX AXI Shutdown Manager",
92};
93
94static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
95	{ .compatible = "xlnx,pr-decoupler-1.00", .data = &decoupler_config },
96	{ .compatible = "xlnx,pr-decoupler", .data = &decoupler_config },
97	{ .compatible = "xlnx,dfx-axi-shutdown-manager-1.00",
98					.data = &shutdown_config },
99	{ .compatible = "xlnx,dfx-axi-shutdown-manager",
100					.data = &shutdown_config },
101	{},
102};
103MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
104
105static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
106{
107	struct xlnx_pr_decoupler_data *priv;
108	struct fpga_bridge *br;
109	int err;
110
111	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
112	if (!priv)
113		return -ENOMEM;
114
115	priv->ipconfig = device_get_match_data(&pdev->dev);
116
117	priv->io_base = devm_platform_ioremap_resource(pdev, 0);
118	if (IS_ERR(priv->io_base))
119		return PTR_ERR(priv->io_base);
120
121	priv->clk = devm_clk_get(&pdev->dev, "aclk");
122	if (IS_ERR(priv->clk))
123		return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
124				     "input clock not found\n");
125
126	err = clk_prepare_enable(priv->clk);
127	if (err) {
128		dev_err(&pdev->dev, "unable to enable clock\n");
129		return err;
130	}
131
132	clk_disable(priv->clk);
133
134	br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
135				  &xlnx_pr_decoupler_br_ops, priv);
136	if (IS_ERR(br)) {
137		err = PTR_ERR(br);
138		dev_err(&pdev->dev, "unable to register %s",
139			priv->ipconfig->name);
140		goto err_clk;
141	}
142
143	platform_set_drvdata(pdev, br);
144
145	return 0;
146
147err_clk:
148	clk_unprepare(priv->clk);
149
150	return err;
151}
152
153static void xlnx_pr_decoupler_remove(struct platform_device *pdev)
154{
155	struct fpga_bridge *bridge = platform_get_drvdata(pdev);
156	struct xlnx_pr_decoupler_data *p = bridge->priv;
157
158	fpga_bridge_unregister(bridge);
159
160	clk_unprepare(p->clk);
161}
162
163static struct platform_driver xlnx_pr_decoupler_driver = {
164	.probe = xlnx_pr_decoupler_probe,
165	.remove_new = xlnx_pr_decoupler_remove,
166	.driver = {
167		.name = "xlnx_pr_decoupler",
168		.of_match_table = xlnx_pr_decoupler_of_match,
169	},
170};
171
172module_platform_driver(xlnx_pr_decoupler_driver);
173
174MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
175MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
176MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
177MODULE_LICENSE("GPL v2");
178