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
21 struct xlnx_config_data {
22 const char *name;
23 };
24
25 struct xlnx_pr_decoupler_data {
26 const struct xlnx_config_data *ipconfig;
27 void __iomem *io_base;
28 struct clk *clk;
29 };
30
xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data * d,u32 offset,u32 val)31 static 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
xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data * d,u32 offset)37 static 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
xlnx_pr_decoupler_enable_set(struct fpga_bridge * bridge,bool enable)43 static 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
xlnx_pr_decoupler_enable_show(struct fpga_bridge * bridge)62 static 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 = readl(priv->io_base);
73
74 clk_disable(priv->clk);
75
76 return !status;
77 }
78
79 static 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
85 static const struct xlnx_config_data decoupler_config = {
86 .name = "Xilinx PR Decoupler",
87 };
88
89 static const struct xlnx_config_data shutdown_config = {
90 .name = "Xilinx DFX AXI Shutdown Manager",
91 };
92
93 static 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 };
102 MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
103 #endif
104
xlnx_pr_decoupler_probe(struct platform_device * pdev)105 static 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 struct resource *res;
112
113 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
114 if (!priv)
115 return -ENOMEM;
116
117 if (np) {
118 const struct of_device_id *match;
119
120 match = of_match_node(xlnx_pr_decoupler_of_match, np);
121 if (match && match->data)
122 priv->ipconfig = match->data;
123 }
124
125 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
126 priv->io_base = devm_ioremap_resource(&pdev->dev, res);
127 if (IS_ERR(priv->io_base))
128 return PTR_ERR(priv->io_base);
129
130 priv->clk = devm_clk_get(&pdev->dev, "aclk");
131 if (IS_ERR(priv->clk))
132 return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
133 "input clock not found\n");
134
135 err = clk_prepare_enable(priv->clk);
136 if (err) {
137 dev_err(&pdev->dev, "unable to enable clock\n");
138 return err;
139 }
140
141 clk_disable(priv->clk);
142
143 br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
144 &xlnx_pr_decoupler_br_ops, priv);
145 if (IS_ERR(br)) {
146 err = PTR_ERR(br);
147 dev_err(&pdev->dev, "unable to register %s",
148 priv->ipconfig->name);
149 goto err_clk;
150 }
151
152 platform_set_drvdata(pdev, br);
153
154 return 0;
155
156 err_clk:
157 clk_unprepare(priv->clk);
158
159 return err;
160 }
161
xlnx_pr_decoupler_remove(struct platform_device * pdev)162 static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
163 {
164 struct fpga_bridge *bridge = platform_get_drvdata(pdev);
165 struct xlnx_pr_decoupler_data *p = bridge->priv;
166
167 fpga_bridge_unregister(bridge);
168
169 clk_unprepare(p->clk);
170
171 return 0;
172 }
173
174 static struct platform_driver xlnx_pr_decoupler_driver = {
175 .probe = xlnx_pr_decoupler_probe,
176 .remove = xlnx_pr_decoupler_remove,
177 .driver = {
178 .name = "xlnx_pr_decoupler",
179 .of_match_table = of_match_ptr(xlnx_pr_decoupler_of_match),
180 },
181 };
182
183 module_platform_driver(xlnx_pr_decoupler_driver);
184
185 MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
186 MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
187 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
188 MODULE_LICENSE("GPL v2");
189