tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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/of_device.h>
14#include <linux/module.h>
15#include <linux/fpga/fpga-bridge.h>
16
17#define CTRL_CMD_DECOUPLE BIT(0)
18#define CTRL_CMD_COUPLE 0
19#define CTRL_OFFSET 0
20
21struct xlnx_config_data {
22 const char *name;
23};
24
25struct xlnx_pr_decoupler_data {
26 const struct xlnx_config_data *ipconfig;
27 void __iomem *io_base;
28 struct clk *clk;
29};
30
31static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,
32 u32 offset, u32 val)
33{
34 writel(val, d->io_base + offset);
35}
36
37static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,
38 u32 offset)
39{
40 return readl(d->io_base + offset);
41}
42
43static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)
44{
45 int err;
46 struct xlnx_pr_decoupler_data *priv = bridge->priv;
47
48 err = clk_enable(priv->clk);
49 if (err)
50 return err;
51
52 if (enable)
53 xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);
54 else
55 xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);
56
57 clk_disable(priv->clk);
58
59 return 0;
60}
61
62static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)
63{
64 const struct xlnx_pr_decoupler_data *priv = bridge->priv;
65 u32 status;
66 int err;
67
68 err = clk_enable(priv->clk);
69 if (err)
70 return err;
71
72 status = xlnx_pr_decouple_read(priv, CTRL_OFFSET);
73
74 clk_disable(priv->clk);
75
76 return !status;
77}
78
79static const struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {
80 .enable_set = xlnx_pr_decoupler_enable_set,
81 .enable_show = xlnx_pr_decoupler_enable_show,
82};
83
84#ifdef CONFIG_OF
85static const struct xlnx_config_data decoupler_config = {
86 .name = "Xilinx PR Decoupler",
87};
88
89static const struct xlnx_config_data shutdown_config = {
90 .name = "Xilinx DFX AXI Shutdown Manager",
91};
92
93static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
94 { .compatible = "xlnx,pr-decoupler-1.00", .data = &decoupler_config },
95 { .compatible = "xlnx,pr-decoupler", .data = &decoupler_config },
96 { .compatible = "xlnx,dfx-axi-shutdown-manager-1.00",
97 .data = &shutdown_config },
98 { .compatible = "xlnx,dfx-axi-shutdown-manager",
99 .data = &shutdown_config },
100 {},
101};
102MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
103#endif
104
105static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
106{
107 struct device_node *np = pdev->dev.of_node;
108 struct xlnx_pr_decoupler_data *priv;
109 struct fpga_bridge *br;
110 int err;
111
112 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
113 if (!priv)
114 return -ENOMEM;
115
116 if (np) {
117 const struct of_device_id *match;
118
119 match = of_match_node(xlnx_pr_decoupler_of_match, np);
120 if (match && match->data)
121 priv->ipconfig = match->data;
122 }
123
124 priv->io_base = devm_platform_ioremap_resource(pdev, 0);
125 if (IS_ERR(priv->io_base))
126 return PTR_ERR(priv->io_base);
127
128 priv->clk = devm_clk_get(&pdev->dev, "aclk");
129 if (IS_ERR(priv->clk))
130 return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
131 "input clock not found\n");
132
133 err = clk_prepare_enable(priv->clk);
134 if (err) {
135 dev_err(&pdev->dev, "unable to enable clock\n");
136 return err;
137 }
138
139 clk_disable(priv->clk);
140
141 br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
142 &xlnx_pr_decoupler_br_ops, priv);
143 if (IS_ERR(br)) {
144 err = PTR_ERR(br);
145 dev_err(&pdev->dev, "unable to register %s",
146 priv->ipconfig->name);
147 goto err_clk;
148 }
149
150 platform_set_drvdata(pdev, br);
151
152 return 0;
153
154err_clk:
155 clk_unprepare(priv->clk);
156
157 return err;
158}
159
160static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
161{
162 struct fpga_bridge *bridge = platform_get_drvdata(pdev);
163 struct xlnx_pr_decoupler_data *p = bridge->priv;
164
165 fpga_bridge_unregister(bridge);
166
167 clk_unprepare(p->clk);
168
169 return 0;
170}
171
172static struct platform_driver xlnx_pr_decoupler_driver = {
173 .probe = xlnx_pr_decoupler_probe,
174 .remove = xlnx_pr_decoupler_remove,
175 .driver = {
176 .name = "xlnx_pr_decoupler",
177 .of_match_table = of_match_ptr(xlnx_pr_decoupler_of_match),
178 },
179};
180
181module_platform_driver(xlnx_pr_decoupler_driver);
182
183MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
184MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
185MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
186MODULE_LICENSE("GPL v2");