drivers/fpga/fpga-mgr.c

   1 /*
   2  * FPGA Manager Core
   3  *
   4  *  Copyright (C) 2013-2015 Altera Corporation
   5  *
   6  * With code from the mailing list:
   7  * Copyright (C) 2013 Xilinx, Inc.
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms and conditions of the GNU General Public License,
  11  * version 2, as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21 #include <linux/firmware.h>
  22 #include <linux/fpga/fpga-mgr.h>
  23 #include <linux/idr.h>
  24 #include <linux/module.h>
  25 #include <linux/of.h>
  26 #include <linux/mutex.h>
  27 #include <linux/slab.h>
  28
  29 static DEFINE_IDA(fpga_mgr_ida);
  30 static struct class *fpga_mgr_class;
  31
  32 /**
  33  * fpga_mgr_buf_load - load fpga from image in buffer
  34  * @mgr:        fpga manager
  35  * @flags:      flags setting fpga confuration modes
  36  * @buf:        buffer contain fpga image
  37  * @count:      byte count of buf
  38  *
  39  * Step the low level fpga manager through the device-specific steps of getting
  40  * an FPGA ready to be configured, writing the image to it, then doing whatever
  41  * post-configuration steps necessary.  This code assumes the caller got the
  42  * mgr pointer from of_fpga_mgr_get() and checked that it is not an error code.
  43  *
  44  * Return: 0 on success, negative error code otherwise.
  45  */
  46 int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, const char *buf,
  47                       size_t count)
  48 {
  49         struct device *dev = &mgr->dev;
  50         int ret;
  51
  52         /*
  53          * Call the low level driver's write_init function.  This will do the
  54          * device-specific things to get the FPGA into the state where it is
  55          * ready to receive an FPGA image.
  56          */
  57         mgr->state = FPGA_MGR_STATE_WRITE_INIT;
  58         ret = mgr->mops->write_init(mgr, flags, buf, count);
  59         if (ret) {
  60                 dev_err(dev, "Error preparing FPGA for writing\n");
  61                 mgr->state = FPGA_MGR_STATE_WRITE_INIT_ERR;
  62                 return ret;
  63         }
  64
  65         /*
  66          * Write the FPGA image to the FPGA.
  67          */
  68         mgr->state = FPGA_MGR_STATE_WRITE;
  69         ret = mgr->mops->write(mgr, buf, count);
  70         if (ret) {
  71                 dev_err(dev, "Error while writing image data to FPGA\n");
  72                 mgr->state = FPGA_MGR_STATE_WRITE_ERR;
  73                 return ret;
  74         }
  75
  76         /*
  77          * After all the FPGA image has been written, do the device specific
  78          * steps to finish and set the FPGA into operating mode.
  79          */
  80         mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE;
  81         ret = mgr->mops->write_complete(mgr, flags);
  82         if (ret) {
  83                 dev_err(dev, "Error after writing image data to FPGA\n");
  84                 mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE_ERR;
  85                 return ret;
  86         }
  87         mgr->state = FPGA_MGR_STATE_OPERATING;
  88
  89         return 0;
  90 }
  91 EXPORT_SYMBOL_GPL(fpga_mgr_buf_load);
  92
  93 /**
  94  * fpga_mgr_firmware_load - request firmware and load to fpga
  95  * @mgr:        fpga manager
  96  * @flags:      flags setting fpga confuration modes
  97  * @image_name: name of image file on the firmware search path
  98  *
  99  * Request an FPGA image using the firmware class, then write out to the FPGA.
 100  * Update the state before each step to provide info on what step failed if
 101  * there is a failure.  This code assumes the caller got the mgr pointer
 102  * from of_fpga_mgr_get() and checked that it is not an error code.
 103  *
 104  * Return: 0 on success, negative error code otherwise.
 105  */
 106 int fpga_mgr_firmware_load(struct fpga_manager *mgr, u32 flags,
 107                            const char *image_name)
 108 {
 109         struct device *dev = &mgr->dev;
 110         const struct firmware *fw;
 111         int ret;
 112
 113         dev_info(dev, "writing %s to %s\n", image_name, mgr->name);
 114
 115         mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
 116
 117         ret = request_firmware(&fw, image_name, dev);
 118         if (ret) {
 119                 mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
 120                 dev_err(dev, "Error requesting firmware %s\n", image_name);
 121                 return ret;
 122         }
 123
 124         ret = fpga_mgr_buf_load(mgr, flags, fw->data, fw->size);
 125
 126         release_firmware(fw);
 127
 128         return ret;
 129 }
 130 EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load);
 131
 132 static const char * const state_str[] = {
 133         [FPGA_MGR_STATE_UNKNOWN] =              "unknown",
 134         [FPGA_MGR_STATE_POWER_OFF] =            "power off",
 135         [FPGA_MGR_STATE_POWER_UP] =             "power up",
 136         [FPGA_MGR_STATE_RESET] =                "reset",
 137
 138         /* requesting FPGA image from firmware */
 139         [FPGA_MGR_STATE_FIRMWARE_REQ] =         "firmware request",
 140         [FPGA_MGR_STATE_FIRMWARE_REQ_ERR] =     "firmware request error",
 141
 142         /* Preparing FPGA to receive image */
 143         [FPGA_MGR_STATE_WRITE_INIT] =           "write init",
 144         [FPGA_MGR_STATE_WRITE_INIT_ERR] =       "write init error",
 145
 146         /* Writing image to FPGA */
 147         [FPGA_MGR_STATE_WRITE] =                "write",
 148         [FPGA_MGR_STATE_WRITE_ERR] =            "write error",
 149
 150         /* Finishing configuration after image has been written */
 151         [FPGA_MGR_STATE_WRITE_COMPLETE] =       "write complete",
 152         [FPGA_MGR_STATE_WRITE_COMPLETE_ERR] =   "write complete error",
 153
 154         /* FPGA reports to be in normal operating mode */
 155         [FPGA_MGR_STATE_OPERATING] =            "operating",
 156 };
 157
 158 static ssize_t name_show(struct device *dev,
 159                          struct device_attribute *attr, char *buf)
 160 {
 161         struct fpga_manager *mgr = to_fpga_manager(dev);
 162
 163         return sprintf(buf, "%s\n", mgr->name);
 164 }
 165
 166 static ssize_t state_show(struct device *dev,
 167                           struct device_attribute *attr, char *buf)
 168 {
 169         struct fpga_manager *mgr = to_fpga_manager(dev);
 170
 171         return sprintf(buf, "%s\n", state_str[mgr->state]);
 172 }
 173
 174 static DEVICE_ATTR_RO(name);
 175 static DEVICE_ATTR_RO(state);
 176
 177 static struct attribute *fpga_mgr_attrs[] = {
 178         &dev_attr_name.attr,
 179         &dev_attr_state.attr,
 180         NULL,
 181 };
 182 ATTRIBUTE_GROUPS(fpga_mgr);
 183
 184 static int fpga_mgr_of_node_match(struct device *dev, const void *data)
 185 {
 186         return dev->of_node == data;
 187 }
 188
 189 /**
 190  * of_fpga_mgr_get - get an exclusive reference to a fpga mgr
 191  * @node:       device node
 192  *
 193  * Given a device node, get an exclusive reference to a fpga mgr.
 194  *
 195  * Return: fpga manager struct or IS_ERR() condition containing error code.
 196  */
 197 struct fpga_manager *of_fpga_mgr_get(struct device_node *node)
 198 {
 199         struct fpga_manager *mgr;
 200         struct device *dev;
 201         int ret = -ENODEV;
 202
 203         dev = class_find_device(fpga_mgr_class, NULL, node,
 204                                 fpga_mgr_of_node_match);
 205         if (!dev)
 206                 return ERR_PTR(-ENODEV);
 207
 208         mgr = to_fpga_manager(dev);
 209         if (!mgr)
 210                 goto err_dev;
 211
 212         /* Get exclusive use of fpga manager */
 213         if (!mutex_trylock(&mgr->ref_mutex)) {
 214                 ret = -EBUSY;
 215                 goto err_dev;
 216         }
 217
 218         if (!try_module_get(dev->parent->driver->owner))
 219                 goto err_ll_mod;
 220
 221         return mgr;
 222
 223 err_ll_mod:
 224         mutex_unlock(&mgr->ref_mutex);
 225 err_dev:
 226         put_device(dev);
 227         return ERR_PTR(ret);
 228 }
 229 EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
 230
 231 /**
 232  * fpga_mgr_put - release a reference to a fpga manager
 233  * @mgr:        fpga manager structure
 234  */
 235 void fpga_mgr_put(struct fpga_manager *mgr)
 236 {
 237         module_put(mgr->dev.parent->driver->owner);
 238         mutex_unlock(&mgr->ref_mutex);
 239         put_device(&mgr->dev);
 240 }
 241 EXPORT_SYMBOL_GPL(fpga_mgr_put);
 242
 243 /**
 244  * fpga_mgr_register - register a low level fpga manager driver
 245  * @dev:        fpga manager device from pdev
 246  * @name:       fpga manager name
 247  * @mops:       pointer to structure of fpga manager ops
 248  * @priv:       fpga manager private data
 249  *
 250  * Return: 0 on success, negative error code otherwise.
 251  */
 252 int fpga_mgr_register(struct device *dev, const char *name,
 253                       const struct fpga_manager_ops *mops,
 254                       void *priv)
 255 {
 256         struct fpga_manager *mgr;
 257         int id, ret;
 258
 259         if (!mops || !mops->write_init || !mops->write ||
 260             !mops->write_complete || !mops->state) {
 261                 dev_err(dev, "Attempt to register without fpga_manager_ops\n");
 262                 return -EINVAL;
 263         }
 264
 265         if (!name || !strlen(name)) {
 266                 dev_err(dev, "Attempt to register with no name!\n");
 267                 return -EINVAL;
 268         }
 269
 270         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
 271         if (!mgr)
 272                 return -ENOMEM;
 273
 274         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
 275         if (id < 0) {
 276                 ret = id;
 277                 goto error_kfree;
 278         }
 279
 280         mutex_init(&mgr->ref_mutex);
 281
 282         mgr->name = name;
 283         mgr->mops = mops;
 284         mgr->priv = priv;
 285
 286         /*
 287          * Initialize framework state by requesting low level driver read state
 288          * from device.  FPGA may be in reset mode or may have been programmed
 289          * by bootloader or EEPROM.
 290          */
 291         mgr->state = mgr->mops->state(mgr);
 292
 293         device_initialize(&mgr->dev);
 294         mgr->dev.class = fpga_mgr_class;
 295         mgr->dev.parent = dev;
 296         mgr->dev.of_node = dev->of_node;
 297         mgr->dev.id = id;
 298         dev_set_drvdata(dev, mgr);
 299
 300         ret = dev_set_name(&mgr->dev, "fpga%d", id);
 301         if (ret)
 302                 goto error_device;
 303
 304         ret = device_add(&mgr->dev);
 305         if (ret)
 306                 goto error_device;
 307
 308         dev_info(&mgr->dev, "%s registered\n", mgr->name);
 309
 310         return 0;
 311
 312 error_device:
 313         ida_simple_remove(&fpga_mgr_ida, id);
 314 error_kfree:
 315         kfree(mgr);
 316
 317         return ret;
 318 }
 319 EXPORT_SYMBOL_GPL(fpga_mgr_register);
 320
 321 /**
 322  * fpga_mgr_unregister - unregister a low level fpga manager driver
 323  * @dev:        fpga manager device from pdev
 324  */
 325 void fpga_mgr_unregister(struct device *dev)
 326 {
 327         struct fpga_manager *mgr = dev_get_drvdata(dev);
 328
 329         dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);
 330
 331         /*
 332          * If the low level driver provides a method for putting fpga into
 333          * a desired state upon unregister, do it.
 334          */
 335         if (mgr->mops->fpga_remove)
 336                 mgr->mops->fpga_remove(mgr);
 337
 338         device_unregister(&mgr->dev);
 339 }
 340 EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
 341
 342 static void fpga_mgr_dev_release(struct device *dev)
 343 {
 344         struct fpga_manager *mgr = to_fpga_manager(dev);
 345
 346         ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
 347         kfree(mgr);
 348 }
 349
 350 static int __init fpga_mgr_class_init(void)
 351 {
 352         pr_info("FPGA manager framework\n");
 353
 354         fpga_mgr_class = class_create(THIS_MODULE, "fpga_manager");
 355         if (IS_ERR(fpga_mgr_class))
 356                 return PTR_ERR(fpga_mgr_class);
 357
 358         fpga_mgr_class->dev_groups = fpga_mgr_groups;
 359         fpga_mgr_class->dev_release = fpga_mgr_dev_release;
 360
 361         return 0;
 362 }
 363
 364 static void __exit fpga_mgr_class_exit(void)
 365 {
 366         class_destroy(fpga_mgr_class);
 367         ida_destroy(&fpga_mgr_ida);
 368 }
 369
 370 MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
 371 MODULE_DESCRIPTION("FPGA manager framework");
 372 MODULE_LICENSE("GPL v2");
 373
 374 subsys_initcall(fpga_mgr_class_init);
 375 module_exit(fpga_mgr_class_exit);