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 23 struct xlnx_config_data { 24 const char *name; 25 }; 26 27 struct xlnx_pr_decoupler_data { 28 const struct xlnx_config_data *ipconfig; 29 void __iomem *io_base; 30 struct clk *clk; 31 }; 32 33 static 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 39 static 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 45 static 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 64 static 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 81 static 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 86 static const struct xlnx_config_data decoupler_config = { 87 .name = "Xilinx PR Decoupler", 88 }; 89 90 static const struct xlnx_config_data shutdown_config = { 91 .name = "Xilinx DFX AXI Shutdown Manager", 92 }; 93 94 static 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 }; 103 MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match); 104 105 static 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; 146 147 err_clk: 148 clk_unprepare(priv->clk); 149 150 return err; 151 } 152 153 static 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 } 162 163 static 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 }; 171 172 module_platform_driver(xlnx_pr_decoupler_driver); 173 174 MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler"); 175 MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>"); 176 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>"); 177 MODULE_LICENSE("GPL v2"); 178