1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2017, National Instruments Corp.
4 * Copyright (c) 2017, Xilix 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
21 struct xlnx_pr_decoupler_data {
22 void __iomem *io_base;
23 struct clk *clk;
24 };
25
xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data * d,u32 offset,u32 val)26 static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,
27 u32 offset, u32 val)
28 {
29 writel(val, d->io_base + offset);
30 }
31
xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data * d,u32 offset)32 static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,
33 u32 offset)
34 {
35 return readl(d->io_base + offset);
36 }
37
xlnx_pr_decoupler_enable_set(struct fpga_bridge * bridge,bool enable)38 static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)
39 {
40 int err;
41 struct xlnx_pr_decoupler_data *priv = bridge->priv;
42
43 err = clk_enable(priv->clk);
44 if (err)
45 return err;
46
47 if (enable)
48 xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);
49 else
50 xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);
51
52 clk_disable(priv->clk);
53
54 return 0;
55 }
56
xlnx_pr_decoupler_enable_show(struct fpga_bridge * bridge)57 static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)
58 {
59 const struct xlnx_pr_decoupler_data *priv = bridge->priv;
60 u32 status;
61 int err;
62
63 err = clk_enable(priv->clk);
64 if (err)
65 return err;
66
67 status = readl(priv->io_base);
68
69 clk_disable(priv->clk);
70
71 return !status;
72 }
73
74 static const struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {
75 .enable_set = xlnx_pr_decoupler_enable_set,
76 .enable_show = xlnx_pr_decoupler_enable_show,
77 };
78
79 static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
80 { .compatible = "xlnx,pr-decoupler-1.00", },
81 { .compatible = "xlnx,pr-decoupler", },
82 {},
83 };
84 MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
85
xlnx_pr_decoupler_probe(struct platform_device * pdev)86 static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
87 {
88 struct xlnx_pr_decoupler_data *priv;
89 struct fpga_bridge *br;
90 int err;
91 struct resource *res;
92
93 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
94 if (!priv)
95 return -ENOMEM;
96
97 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
98 priv->io_base = devm_ioremap_resource(&pdev->dev, res);
99 if (IS_ERR(priv->io_base))
100 return PTR_ERR(priv->io_base);
101
102 priv->clk = devm_clk_get(&pdev->dev, "aclk");
103 if (IS_ERR(priv->clk)) {
104 dev_err(&pdev->dev, "input clock not found\n");
105 return PTR_ERR(priv->clk);
106 }
107
108 err = clk_prepare_enable(priv->clk);
109 if (err) {
110 dev_err(&pdev->dev, "unable to enable clock\n");
111 return err;
112 }
113
114 clk_disable(priv->clk);
115
116 br = devm_fpga_bridge_create(&pdev->dev, "Xilinx PR Decoupler",
117 &xlnx_pr_decoupler_br_ops, priv);
118 if (!br) {
119 err = -ENOMEM;
120 goto err_clk;
121 }
122
123 platform_set_drvdata(pdev, br);
124
125 err = fpga_bridge_register(br);
126 if (err) {
127 dev_err(&pdev->dev, "unable to register Xilinx PR Decoupler");
128 goto err_clk;
129 }
130
131 return 0;
132
133 err_clk:
134 clk_unprepare(priv->clk);
135
136 return err;
137 }
138
xlnx_pr_decoupler_remove(struct platform_device * pdev)139 static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
140 {
141 struct fpga_bridge *bridge = platform_get_drvdata(pdev);
142 struct xlnx_pr_decoupler_data *p = bridge->priv;
143
144 fpga_bridge_unregister(bridge);
145
146 clk_unprepare(p->clk);
147
148 return 0;
149 }
150
151 static struct platform_driver xlnx_pr_decoupler_driver = {
152 .probe = xlnx_pr_decoupler_probe,
153 .remove = xlnx_pr_decoupler_remove,
154 .driver = {
155 .name = "xlnx_pr_decoupler",
156 .of_match_table = of_match_ptr(xlnx_pr_decoupler_of_match),
157 },
158 };
159
160 module_platform_driver(xlnx_pr_decoupler_driver);
161
162 MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
163 MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
164 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
165 MODULE_LICENSE("GPL v2");
166
