1 /* 2 * FPGA Region - Device Tree support for FPGA programming under Linux 3 * 4 * Copyright (C) 2013-2016 Altera Corporation 5 * Copyright (C) 2017 Intel Corporation 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/fpga/fpga-bridge.h> 21 #include <linux/fpga/fpga-mgr.h> 22 #include <linux/fpga/fpga-region.h> 23 #include <linux/idr.h> 24 #include <linux/kernel.h> 25 #include <linux/list.h> 26 #include <linux/module.h> 27 #include <linux/slab.h> 28 #include <linux/spinlock.h> 29 30 static DEFINE_IDA(fpga_region_ida); 31 static struct class *fpga_region_class; 32 33 struct fpga_region *fpga_region_class_find( 34 struct device *start, const void *data, 35 int (*match)(struct device *, const void *)) 36 { 37 struct device *dev; 38 39 dev = class_find_device(fpga_region_class, start, data, match); 40 if (!dev) 41 return NULL; 42 43 return to_fpga_region(dev); 44 } 45 EXPORT_SYMBOL_GPL(fpga_region_class_find); 46 47 /** 48 * fpga_region_get - get an exclusive reference to a fpga region 49 * @region: FPGA Region struct 50 * 51 * Caller should call fpga_region_put() when done with region. 52 * 53 * Return fpga_region struct if successful. 54 * Return -EBUSY if someone already has a reference to the region. 55 * Return -ENODEV if @np is not a FPGA Region. 56 */ 57 static struct fpga_region *fpga_region_get(struct fpga_region *region) 58 { 59 struct device *dev = ®ion->dev; 60 61 if (!mutex_trylock(®ion->mutex)) { 62 dev_dbg(dev, "%s: FPGA Region already in use\n", __func__); 63 return ERR_PTR(-EBUSY); 64 } 65 66 get_device(dev); 67 if (!try_module_get(dev->parent->driver->owner)) { 68 put_device(dev); 69 mutex_unlock(®ion->mutex); 70 return ERR_PTR(-ENODEV); 71 } 72 73 dev_dbg(dev, "get\n"); 74 75 return region; 76 } 77 78 /** 79 * fpga_region_put - release a reference to a region 80 * 81 * @region: FPGA region 82 */ 83 static void fpga_region_put(struct fpga_region *region) 84 { 85 struct device *dev = ®ion->dev; 86 87 dev_dbg(dev, "put\n"); 88 89 module_put(dev->parent->driver->owner); 90 put_device(dev); 91 mutex_unlock(®ion->mutex); 92 } 93 94 /** 95 * fpga_region_program_fpga - program FPGA 96 * @region: FPGA region 97 * Program an FPGA using fpga image info (region->info). 98 * If the region has a get_bridges function, the exclusive reference for the 99 * bridges will be held if programming succeeds. This is intended to prevent 100 * reprogramming the region until the caller considers it safe to do so. 101 * The caller will need to call fpga_bridges_put() before attempting to 102 * reprogram the region. 103 * Return 0 for success or negative error code. 104 */ 105 int fpga_region_program_fpga(struct fpga_region *region) 106 { 107 struct device *dev = ®ion->dev; 108 struct fpga_image_info *info = region->info; 109 int ret; 110 111 region = fpga_region_get(region); 112 if (IS_ERR(region)) { 113 dev_err(dev, "failed to get FPGA region\n"); 114 return PTR_ERR(region); 115 } 116 117 ret = fpga_mgr_lock(region->mgr); 118 if (ret) { 119 dev_err(dev, "FPGA manager is busy\n"); 120 goto err_put_region; 121 } 122 123 /* 124 * In some cases, we already have a list of bridges in the 125 * fpga region struct. Or we don't have any bridges. 126 */ 127 if (region->get_bridges) { 128 ret = region->get_bridges(region); 129 if (ret) { 130 dev_err(dev, "failed to get fpga region bridges\n"); 131 goto err_unlock_mgr; 132 } 133 } 134 135 ret = fpga_bridges_disable(®ion->bridge_list); 136 if (ret) { 137 dev_err(dev, "failed to disable bridges\n"); 138 goto err_put_br; 139 } 140 141 ret = fpga_mgr_load(region->mgr, info); 142 if (ret) { 143 dev_err(dev, "failed to load FPGA image\n"); 144 goto err_put_br; 145 } 146 147 ret = fpga_bridges_enable(®ion->bridge_list); 148 if (ret) { 149 dev_err(dev, "failed to enable region bridges\n"); 150 goto err_put_br; 151 } 152 153 fpga_mgr_unlock(region->mgr); 154 fpga_region_put(region); 155 156 return 0; 157 158 err_put_br: 159 if (region->get_bridges) 160 fpga_bridges_put(®ion->bridge_list); 161 err_unlock_mgr: 162 fpga_mgr_unlock(region->mgr); 163 err_put_region: 164 fpga_region_put(region); 165 166 return ret; 167 } 168 EXPORT_SYMBOL_GPL(fpga_region_program_fpga); 169 170 int fpga_region_register(struct device *dev, struct fpga_region *region) 171 { 172 int id, ret = 0; 173 174 id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL); 175 if (id < 0) 176 return id; 177 178 mutex_init(®ion->mutex); 179 INIT_LIST_HEAD(®ion->bridge_list); 180 device_initialize(®ion->dev); 181 region->dev.groups = region->groups; 182 region->dev.class = fpga_region_class; 183 region->dev.parent = dev; 184 region->dev.of_node = dev->of_node; 185 region->dev.id = id; 186 dev_set_drvdata(dev, region); 187 188 ret = dev_set_name(®ion->dev, "region%d", id); 189 if (ret) 190 goto err_remove; 191 192 ret = device_add(®ion->dev); 193 if (ret) 194 goto err_remove; 195 196 return 0; 197 198 err_remove: 199 ida_simple_remove(&fpga_region_ida, id); 200 return ret; 201 } 202 EXPORT_SYMBOL_GPL(fpga_region_register); 203 204 int fpga_region_unregister(struct fpga_region *region) 205 { 206 device_unregister(®ion->dev); 207 208 return 0; 209 } 210 EXPORT_SYMBOL_GPL(fpga_region_unregister); 211 212 static void fpga_region_dev_release(struct device *dev) 213 { 214 struct fpga_region *region = to_fpga_region(dev); 215 216 ida_simple_remove(&fpga_region_ida, region->dev.id); 217 } 218 219 /** 220 * fpga_region_init - init function for fpga_region class 221 * Creates the fpga_region class and registers a reconfig notifier. 222 */ 223 static int __init fpga_region_init(void) 224 { 225 fpga_region_class = class_create(THIS_MODULE, "fpga_region"); 226 if (IS_ERR(fpga_region_class)) 227 return PTR_ERR(fpga_region_class); 228 229 fpga_region_class->dev_release = fpga_region_dev_release; 230 231 return 0; 232 } 233 234 static void __exit fpga_region_exit(void) 235 { 236 class_destroy(fpga_region_class); 237 ida_destroy(&fpga_region_ida); 238 } 239 240 subsys_initcall(fpga_region_init); 241 module_exit(fpga_region_exit); 242 243 MODULE_DESCRIPTION("FPGA Region"); 244 MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); 245 MODULE_LICENSE("GPL v2"); 246