drivers/input/rmi4/rmi_bus.c

   1 /*
   2  * Copyright (c) 2011-2016 Synaptics Incorporated
   3  * Copyright (c) 2011 Unixphere
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/device.h>
  12 #include <linux/list.h>
  13 #include <linux/pm.h>
  14 #include <linux/rmi.h>
  15 #include <linux/slab.h>
  16 #include <linux/types.h>
  17 #include <linux/of.h>
  18 #include "rmi_bus.h"
  19 #include "rmi_driver.h"
  20
  21 static int debug_flags;
  22 module_param(debug_flags, int, 0644);
  23 MODULE_PARM_DESC(debug_flags, "control debugging information");
  24
  25 void rmi_dbg(int flags, struct device *dev, const char *fmt, ...)
  26 {
  27         struct va_format vaf;
  28         va_list args;
  29
  30         if (flags & debug_flags) {
  31                 va_start(args, fmt);
  32
  33                 vaf.fmt = fmt;
  34                 vaf.va = &args;
  35
  36                 dev_printk(KERN_DEBUG, dev, "%pV", &vaf);
  37
  38                 va_end(args);
  39         }
  40 }
  41 EXPORT_SYMBOL_GPL(rmi_dbg);
  42
  43 /*
  44  * RMI Physical devices
  45  *
  46  * Physical RMI device consists of several functions serving particular
  47  * purpose. For example F11 is a 2D touch sensor while F01 is a generic
  48  * function present in every RMI device.
  49  */
  50
  51 static void rmi_release_device(struct device *dev)
  52 {
  53         struct rmi_device *rmi_dev = to_rmi_device(dev);
  54
  55         kfree(rmi_dev);
  56 }
  57
  58 static struct device_type rmi_device_type = {
  59         .name           = "rmi4_sensor",
  60         .release        = rmi_release_device,
  61 };
  62
  63 bool rmi_is_physical_device(struct device *dev)
  64 {
  65         return dev->type == &rmi_device_type;
  66 }
  67
  68 /**
  69  * rmi_register_transport_device - register a transport device connection
  70  * on the RMI bus.  Transport drivers provide communication from the devices
  71  * on a bus (such as SPI, I2C, and so on) to the RMI4 sensor.
  72  *
  73  * @xport: the transport device to register
  74  */
  75 int rmi_register_transport_device(struct rmi_transport_dev *xport)
  76 {
  77         static atomic_t transport_device_count = ATOMIC_INIT(0);
  78         struct rmi_device *rmi_dev;
  79         int error;
  80
  81         rmi_dev = kzalloc(sizeof(struct rmi_device), GFP_KERNEL);
  82         if (!rmi_dev)
  83                 return -ENOMEM;
  84
  85         device_initialize(&rmi_dev->dev);
  86
  87         rmi_dev->xport = xport;
  88         rmi_dev->number = atomic_inc_return(&transport_device_count) - 1;
  89
  90         dev_set_name(&rmi_dev->dev, "rmi4-%02d", rmi_dev->number);
  91
  92         rmi_dev->dev.bus = &rmi_bus_type;
  93         rmi_dev->dev.type = &rmi_device_type;
  94
  95         xport->rmi_dev = rmi_dev;
  96
  97         error = device_add(&rmi_dev->dev);
  98         if (error)
  99                 goto err_put_device;
 100
 101         rmi_dbg(RMI_DEBUG_CORE, xport->dev,
 102                 "%s: Registered %s as %s.\n", __func__,
 103                 dev_name(rmi_dev->xport->dev), dev_name(&rmi_dev->dev));
 104
 105         return 0;
 106
 107 err_put_device:
 108         put_device(&rmi_dev->dev);
 109         return error;
 110 }
 111 EXPORT_SYMBOL_GPL(rmi_register_transport_device);
 112
 113 /**
 114  * rmi_unregister_transport_device - unregister a transport device connection
 115  * @xport: the transport driver to unregister
 116  *
 117  */
 118 void rmi_unregister_transport_device(struct rmi_transport_dev *xport)
 119 {
 120         struct rmi_device *rmi_dev = xport->rmi_dev;
 121
 122         device_del(&rmi_dev->dev);
 123         put_device(&rmi_dev->dev);
 124 }
 125 EXPORT_SYMBOL(rmi_unregister_transport_device);
 126
 127
 128 /* Function specific stuff */
 129
 130 static void rmi_release_function(struct device *dev)
 131 {
 132         struct rmi_function *fn = to_rmi_function(dev);
 133
 134         kfree(fn);
 135 }
 136
 137 static struct device_type rmi_function_type = {
 138         .name           = "rmi4_function",
 139         .release        = rmi_release_function,
 140 };
 141
 142 bool rmi_is_function_device(struct device *dev)
 143 {
 144         return dev->type == &rmi_function_type;
 145 }
 146
 147 static int rmi_function_match(struct device *dev, struct device_driver *drv)
 148 {
 149         struct rmi_function_handler *handler = to_rmi_function_handler(drv);
 150         struct rmi_function *fn = to_rmi_function(dev);
 151
 152         return fn->fd.function_number == handler->func;
 153 }
 154
 155 #ifdef CONFIG_OF
 156 static void rmi_function_of_probe(struct rmi_function *fn)
 157 {
 158         char of_name[9];
 159         struct device_node *node = fn->rmi_dev->xport->dev->of_node;
 160
 161         snprintf(of_name, sizeof(of_name), "rmi4-f%02x",
 162                 fn->fd.function_number);
 163         fn->dev.of_node = of_get_child_by_name(node, of_name);
 164 }
 165 #else
 166 static inline void rmi_function_of_probe(struct rmi_function *fn)
 167 {}
 168 #endif
 169
 170 static int rmi_function_probe(struct device *dev)
 171 {
 172         struct rmi_function *fn = to_rmi_function(dev);
 173         struct rmi_function_handler *handler =
 174                                         to_rmi_function_handler(dev->driver);
 175         int error;
 176
 177         rmi_function_of_probe(fn);
 178
 179         if (handler->probe) {
 180                 error = handler->probe(fn);
 181                 return error;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int rmi_function_remove(struct device *dev)
 188 {
 189         struct rmi_function *fn = to_rmi_function(dev);
 190         struct rmi_function_handler *handler =
 191                                         to_rmi_function_handler(dev->driver);
 192
 193         if (handler->remove)
 194                 handler->remove(fn);
 195
 196         return 0;
 197 }
 198
 199 int rmi_register_function(struct rmi_function *fn)
 200 {
 201         struct rmi_device *rmi_dev = fn->rmi_dev;
 202         int error;
 203
 204         device_initialize(&fn->dev);
 205
 206         dev_set_name(&fn->dev, "%s.fn%02x",
 207                      dev_name(&rmi_dev->dev), fn->fd.function_number);
 208
 209         fn->dev.parent = &rmi_dev->dev;
 210         fn->dev.type = &rmi_function_type;
 211         fn->dev.bus = &rmi_bus_type;
 212
 213         error = device_add(&fn->dev);
 214         if (error) {
 215                 dev_err(&rmi_dev->dev,
 216                         "Failed device_register function device %s\n",
 217                         dev_name(&fn->dev));
 218                 goto err_put_device;
 219         }
 220
 221         rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Registered F%02X.\n",
 222                         fn->fd.function_number);
 223
 224         return 0;
 225
 226 err_put_device:
 227         put_device(&fn->dev);
 228         return error;
 229 }
 230
 231 void rmi_unregister_function(struct rmi_function *fn)
 232 {
 233         device_del(&fn->dev);
 234         of_node_put(fn->dev.of_node);
 235         put_device(&fn->dev);
 236 }
 237
 238 /**
 239  * rmi_register_function_handler - register a handler for an RMI function
 240  * @handler: RMI handler that should be registered.
 241  * @module: pointer to module that implements the handler
 242  * @mod_name: name of the module implementing the handler
 243  *
 244  * This function performs additional setup of RMI function handler and
 245  * registers it with the RMI core so that it can be bound to
 246  * RMI function devices.
 247  */
 248 int __rmi_register_function_handler(struct rmi_function_handler *handler,
 249                                      struct module *owner,
 250                                      const char *mod_name)
 251 {
 252         struct device_driver *driver = &handler->driver;
 253         int error;
 254
 255         driver->bus = &rmi_bus_type;
 256         driver->owner = owner;
 257         driver->mod_name = mod_name;
 258         driver->probe = rmi_function_probe;
 259         driver->remove = rmi_function_remove;
 260
 261         error = driver_register(&handler->driver);
 262         if (error) {
 263                 pr_err("driver_register() failed for %s, error: %d\n",
 264                         handler->driver.name, error);
 265                 return error;
 266         }
 267
 268         return 0;
 269 }
 270 EXPORT_SYMBOL_GPL(__rmi_register_function_handler);
 271
 272 /**
 273  * rmi_unregister_function_handler - unregister given RMI function handler
 274  * @handler: RMI handler that should be unregistered.
 275  *
 276  * This function unregisters given function handler from RMI core which
 277  * causes it to be unbound from the function devices.
 278  */
 279 void rmi_unregister_function_handler(struct rmi_function_handler *handler)
 280 {
 281         driver_unregister(&handler->driver);
 282 }
 283 EXPORT_SYMBOL_GPL(rmi_unregister_function_handler);
 284
 285 /* Bus specific stuff */
 286
 287 static int rmi_bus_match(struct device *dev, struct device_driver *drv)
 288 {
 289         bool physical = rmi_is_physical_device(dev);
 290
 291         /* First see if types are not compatible */
 292         if (physical != rmi_is_physical_driver(drv))
 293                 return 0;
 294
 295         return physical || rmi_function_match(dev, drv);
 296 }
 297
 298 struct bus_type rmi_bus_type = {
 299         .match          = rmi_bus_match,
 300         .name           = "rmi4",
 301 };
 302
 303 static struct rmi_function_handler *fn_handlers[] = {
 304         &rmi_f01_handler,
 305 #ifdef CONFIG_RMI4_F11
 306         &rmi_f11_handler,
 307 #endif
 308 #ifdef CONFIG_RMI4_F12
 309         &rmi_f12_handler,
 310 #endif
 311 #ifdef CONFIG_RMI4_F30
 312         &rmi_f30_handler,
 313 #endif
 314 #ifdef CONFIG_RMI4_F54
 315         &rmi_f54_handler,
 316 #endif
 317 };
 318
 319 static void __rmi_unregister_function_handlers(int start_idx)
 320 {
 321         int i;
 322
 323         for (i = start_idx; i >= 0; i--)
 324                 rmi_unregister_function_handler(fn_handlers[i]);
 325 }
 326
 327 static void rmi_unregister_function_handlers(void)
 328 {
 329         __rmi_unregister_function_handlers(ARRAY_SIZE(fn_handlers) - 1);
 330 }
 331
 332 static int rmi_register_function_handlers(void)
 333 {
 334         int ret;
 335         int i;
 336
 337         for (i = 0; i < ARRAY_SIZE(fn_handlers); i++)   {
 338                 ret = rmi_register_function_handler(fn_handlers[i]);
 339                 if (ret) {
 340                         pr_err("%s: error registering the RMI F%02x handler: %d\n",
 341                                 __func__, fn_handlers[i]->func, ret);
 342                         goto err_unregister_function_handlers;
 343                 }
 344         }
 345
 346         return 0;
 347
 348 err_unregister_function_handlers:
 349         __rmi_unregister_function_handlers(i - 1);
 350         return ret;
 351 }
 352
 353 int rmi_of_property_read_u32(struct device *dev, u32 *result,
 354                                 const char *prop, bool optional)
 355 {
 356         int retval;
 357         u32 val = 0;
 358
 359         retval = of_property_read_u32(dev->of_node, prop, &val);
 360         if (retval && (!optional && retval == -EINVAL)) {
 361                 dev_err(dev, "Failed to get %s value: %d\n",
 362                         prop, retval);
 363                 return retval;
 364         }
 365         *result = val;
 366
 367         return 0;
 368 }
 369 EXPORT_SYMBOL_GPL(rmi_of_property_read_u32);
 370
 371 static int __init rmi_bus_init(void)
 372 {
 373         int error;
 374
 375         error = bus_register(&rmi_bus_type);
 376         if (error) {
 377                 pr_err("%s: error registering the RMI bus: %d\n",
 378                         __func__, error);
 379                 return error;
 380         }
 381
 382         error = rmi_register_function_handlers();
 383         if (error)
 384                 goto err_unregister_bus;
 385
 386         error = rmi_register_physical_driver();
 387         if (error) {
 388                 pr_err("%s: error registering the RMI physical driver: %d\n",
 389                         __func__, error);
 390                 goto err_unregister_bus;
 391         }
 392
 393         return 0;
 394
 395 err_unregister_bus:
 396         bus_unregister(&rmi_bus_type);
 397         return error;
 398 }
 399 module_init(rmi_bus_init);
 400
 401 static void __exit rmi_bus_exit(void)
 402 {
 403         /*
 404          * We should only ever get here if all drivers are unloaded, so
 405          * all we have to do at this point is unregister ourselves.
 406          */
 407
 408         rmi_unregister_physical_driver();
 409         rmi_unregister_function_handlers();
 410         bus_unregister(&rmi_bus_type);
 411 }
 412 module_exit(rmi_bus_exit);
 413
 414 MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com");
 415 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com");
 416 MODULE_DESCRIPTION("RMI bus");
 417 MODULE_LICENSE("GPL");
 418 MODULE_VERSION(RMI_DRIVER_VERSION);