drivers/input/rmi4/rmi_bus.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2011-2016 Synaptics Incorporated
   4  * Copyright (c) 2011 Unixphere
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/device.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqdomain.h>
  11 #include <linux/list.h>
  12 #include <linux/pm.h>
  13 #include <linux/rmi.h>
  14 #include <linux/slab.h>
  15 #include <linux/types.h>
  16 #include <linux/of.h>
  17 #include "rmi_bus.h"
  18 #include "rmi_driver.h"
  19
  20 static int debug_flags;
  21 module_param(debug_flags, int, 0644);
  22 MODULE_PARM_DESC(debug_flags, "control debugging information");
  23
  24 void rmi_dbg(int flags, struct device *dev, const char *fmt, ...)
  25 {
  26         struct va_format vaf;
  27         va_list args;
  28
  29         if (flags & debug_flags) {
  30                 va_start(args, fmt);
  31
  32                 vaf.fmt = fmt;
  33                 vaf.va = &args;
  34
  35                 dev_printk(KERN_DEBUG, dev, "%pV", &vaf);
  36
  37                 va_end(args);
  38         }
  39 }
  40 EXPORT_SYMBOL_GPL(rmi_dbg);
  41
  42 /*
  43  * RMI Physical devices
  44  *
  45  * Physical RMI device consists of several functions serving particular
  46  * purpose. For example F11 is a 2D touch sensor while F01 is a generic
  47  * function present in every RMI device.
  48  */
  49
  50 static void rmi_release_device(struct device *dev)
  51 {
  52         struct rmi_device *rmi_dev = to_rmi_device(dev);
  53
  54         kfree(rmi_dev);
  55 }
  56
  57 static const struct device_type rmi_device_type = {
  58         .name           = "rmi4_sensor",
  59         .release        = rmi_release_device,
  60 };
  61
  62 bool rmi_is_physical_device(struct device *dev)
  63 {
  64         return dev->type == &rmi_device_type;
  65 }
  66
  67 /**
  68  * rmi_register_transport_device - register a transport device connection
  69  * on the RMI bus.  Transport drivers provide communication from the devices
  70  * on a bus (such as SPI, I2C, and so on) to the RMI4 sensor.
  71  *
  72  * @xport: the transport device to register
  73  */
  74 int rmi_register_transport_device(struct rmi_transport_dev *xport)
  75 {
  76         static atomic_t transport_device_count = ATOMIC_INIT(0);
  77         struct rmi_device *rmi_dev;
  78         int error;
  79
  80         rmi_dev = kzalloc(sizeof(struct rmi_device), GFP_KERNEL);
  81         if (!rmi_dev)
  82                 return -ENOMEM;
  83
  84         device_initialize(&rmi_dev->dev);
  85
  86         rmi_dev->xport = xport;
  87         rmi_dev->number = atomic_inc_return(&transport_device_count) - 1;
  88
  89         dev_set_name(&rmi_dev->dev, "rmi4-%02d", rmi_dev->number);
  90
  91         rmi_dev->dev.bus = &rmi_bus_type;
  92         rmi_dev->dev.type = &rmi_device_type;
  93
  94         xport->rmi_dev = rmi_dev;
  95
  96         error = device_add(&rmi_dev->dev);
  97         if (error)
  98                 goto err_put_device;
  99
 100         rmi_dbg(RMI_DEBUG_CORE, xport->dev,
 101                 "%s: Registered %s as %s.\n", __func__,
 102                 dev_name(rmi_dev->xport->dev), dev_name(&rmi_dev->dev));
 103
 104         return 0;
 105
 106 err_put_device:
 107         put_device(&rmi_dev->dev);
 108         return error;
 109 }
 110 EXPORT_SYMBOL_GPL(rmi_register_transport_device);
 111
 112 /**
 113  * rmi_unregister_transport_device - unregister a transport device connection
 114  * @xport: the transport driver to unregister
 115  *
 116  */
 117 void rmi_unregister_transport_device(struct rmi_transport_dev *xport)
 118 {
 119         struct rmi_device *rmi_dev = xport->rmi_dev;
 120
 121         device_del(&rmi_dev->dev);
 122         put_device(&rmi_dev->dev);
 123 }
 124 EXPORT_SYMBOL(rmi_unregister_transport_device);
 125
 126
 127 /* Function specific stuff */
 128
 129 static void rmi_release_function(struct device *dev)
 130 {
 131         struct rmi_function *fn = to_rmi_function(dev);
 132
 133         kfree(fn);
 134 }
 135
 136 static const struct device_type rmi_function_type = {
 137         .name           = "rmi4_function",
 138         .release        = rmi_release_function,
 139 };
 140
 141 bool rmi_is_function_device(struct device *dev)
 142 {
 143         return dev->type == &rmi_function_type;
 144 }
 145
 146 static int rmi_function_match(struct device *dev, struct device_driver *drv)
 147 {
 148         struct rmi_function_handler *handler = to_rmi_function_handler(drv);
 149         struct rmi_function *fn = to_rmi_function(dev);
 150
 151         return fn->fd.function_number == handler->func;
 152 }
 153
 154 #ifdef CONFIG_OF
 155 static void rmi_function_of_probe(struct rmi_function *fn)
 156 {
 157         char of_name[9];
 158         struct device_node *node = fn->rmi_dev->xport->dev->of_node;
 159
 160         snprintf(of_name, sizeof(of_name), "rmi4-f%02x",
 161                 fn->fd.function_number);
 162         fn->dev.of_node = of_get_child_by_name(node, of_name);
 163 }
 164 #else
 165 static inline void rmi_function_of_probe(struct rmi_function *fn)
 166 {}
 167 #endif
 168
 169 static struct irq_chip rmi_irq_chip = {
 170         .name = "rmi4",
 171 };
 172
 173 static int rmi_create_function_irq(struct rmi_function *fn,
 174                                    struct rmi_function_handler *handler)
 175 {
 176         struct rmi_driver_data *drvdata = dev_get_drvdata(&fn->rmi_dev->dev);
 177         int i, error;
 178
 179         for (i = 0; i < fn->num_of_irqs; i++) {
 180                 set_bit(fn->irq_pos + i, fn->irq_mask);
 181
 182                 fn->irq[i] = irq_create_mapping(drvdata->irqdomain,
 183                                                 fn->irq_pos + i);
 184
 185                 irq_set_chip_data(fn->irq[i], fn);
 186                 irq_set_chip_and_handler(fn->irq[i], &rmi_irq_chip,
 187                                          handle_simple_irq);
 188                 irq_set_nested_thread(fn->irq[i], 1);
 189
 190                 error = devm_request_threaded_irq(&fn->dev, fn->irq[i], NULL,
 191                                         handler->attention, IRQF_ONESHOT,
 192                                         dev_name(&fn->dev), fn);
 193                 if (error) {
 194                         dev_err(&fn->dev, "Error %d registering IRQ\n", error);
 195                         return error;
 196                 }
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int rmi_function_probe(struct device *dev)
 203 {
 204         struct rmi_function *fn = to_rmi_function(dev);
 205         struct rmi_function_handler *handler =
 206                                         to_rmi_function_handler(dev->driver);
 207         int error;
 208
 209         rmi_function_of_probe(fn);
 210
 211         if (handler->probe) {
 212                 error = handler->probe(fn);
 213                 if (error)
 214                         return error;
 215         }
 216
 217         if (fn->num_of_irqs && handler->attention) {
 218                 error = rmi_create_function_irq(fn, handler);
 219                 if (error)
 220                         return error;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int rmi_function_remove(struct device *dev)
 227 {
 228         struct rmi_function *fn = to_rmi_function(dev);
 229         struct rmi_function_handler *handler =
 230                                         to_rmi_function_handler(dev->driver);
 231
 232         if (handler->remove)
 233                 handler->remove(fn);
 234
 235         return 0;
 236 }
 237
 238 int rmi_register_function(struct rmi_function *fn)
 239 {
 240         struct rmi_device *rmi_dev = fn->rmi_dev;
 241         int error;
 242
 243         device_initialize(&fn->dev);
 244
 245         dev_set_name(&fn->dev, "%s.fn%02x",
 246                      dev_name(&rmi_dev->dev), fn->fd.function_number);
 247
 248         fn->dev.parent = &rmi_dev->dev;
 249         fn->dev.type = &rmi_function_type;
 250         fn->dev.bus = &rmi_bus_type;
 251
 252         error = device_add(&fn->dev);
 253         if (error) {
 254                 dev_err(&rmi_dev->dev,
 255                         "Failed device_register function device %s\n",
 256                         dev_name(&fn->dev));
 257                 goto err_put_device;
 258         }
 259
 260         rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Registered F%02X.\n",
 261                         fn->fd.function_number);
 262
 263         return 0;
 264
 265 err_put_device:
 266         put_device(&fn->dev);
 267         return error;
 268 }
 269
 270 void rmi_unregister_function(struct rmi_function *fn)
 271 {
 272         int i;
 273
 274         rmi_dbg(RMI_DEBUG_CORE, &fn->dev, "Unregistering F%02X.\n",
 275                         fn->fd.function_number);
 276
 277         device_del(&fn->dev);
 278         of_node_put(fn->dev.of_node);
 279         put_device(&fn->dev);
 280
 281         for (i = 0; i < fn->num_of_irqs; i++)
 282                 irq_dispose_mapping(fn->irq[i]);
 283
 284 }
 285
 286 /**
 287  * rmi_register_function_handler - register a handler for an RMI function
 288  * @handler: RMI handler that should be registered.
 289  * @module: pointer to module that implements the handler
 290  * @mod_name: name of the module implementing the handler
 291  *
 292  * This function performs additional setup of RMI function handler and
 293  * registers it with the RMI core so that it can be bound to
 294  * RMI function devices.
 295  */
 296 int __rmi_register_function_handler(struct rmi_function_handler *handler,
 297                                      struct module *owner,
 298                                      const char *mod_name)
 299 {
 300         struct device_driver *driver = &handler->driver;
 301         int error;
 302
 303         driver->bus = &rmi_bus_type;
 304         driver->owner = owner;
 305         driver->mod_name = mod_name;
 306         driver->probe = rmi_function_probe;
 307         driver->remove = rmi_function_remove;
 308
 309         error = driver_register(driver);
 310         if (error) {
 311                 pr_err("driver_register() failed for %s, error: %d\n",
 312                         driver->name, error);
 313                 return error;
 314         }
 315
 316         return 0;
 317 }
 318 EXPORT_SYMBOL_GPL(__rmi_register_function_handler);
 319
 320 /**
 321  * rmi_unregister_function_handler - unregister given RMI function handler
 322  * @handler: RMI handler that should be unregistered.
 323  *
 324  * This function unregisters given function handler from RMI core which
 325  * causes it to be unbound from the function devices.
 326  */
 327 void rmi_unregister_function_handler(struct rmi_function_handler *handler)
 328 {
 329         driver_unregister(&handler->driver);
 330 }
 331 EXPORT_SYMBOL_GPL(rmi_unregister_function_handler);
 332
 333 /* Bus specific stuff */
 334
 335 static int rmi_bus_match(struct device *dev, struct device_driver *drv)
 336 {
 337         bool physical = rmi_is_physical_device(dev);
 338
 339         /* First see if types are not compatible */
 340         if (physical != rmi_is_physical_driver(drv))
 341                 return 0;
 342
 343         return physical || rmi_function_match(dev, drv);
 344 }
 345
 346 struct bus_type rmi_bus_type = {
 347         .match          = rmi_bus_match,
 348         .name           = "rmi4",
 349 };
 350
 351 static struct rmi_function_handler *fn_handlers[] = {
 352         &rmi_f01_handler,
 353 #ifdef CONFIG_RMI4_F03
 354         &rmi_f03_handler,
 355 #endif
 356 #ifdef CONFIG_RMI4_F11
 357         &rmi_f11_handler,
 358 #endif
 359 #ifdef CONFIG_RMI4_F12
 360         &rmi_f12_handler,
 361 #endif
 362 #ifdef CONFIG_RMI4_F30
 363         &rmi_f30_handler,
 364 #endif
 365 #ifdef CONFIG_RMI4_F34
 366         &rmi_f34_handler,
 367 #endif
 368 #ifdef CONFIG_RMI4_F54
 369         &rmi_f54_handler,
 370 #endif
 371 #ifdef CONFIG_RMI4_F55
 372         &rmi_f55_handler,
 373 #endif
 374 };
 375
 376 static void __rmi_unregister_function_handlers(int start_idx)
 377 {
 378         int i;
 379
 380         for (i = start_idx; i >= 0; i--)
 381                 rmi_unregister_function_handler(fn_handlers[i]);
 382 }
 383
 384 static void rmi_unregister_function_handlers(void)
 385 {
 386         __rmi_unregister_function_handlers(ARRAY_SIZE(fn_handlers) - 1);
 387 }
 388
 389 static int rmi_register_function_handlers(void)
 390 {
 391         int ret;
 392         int i;
 393
 394         for (i = 0; i < ARRAY_SIZE(fn_handlers); i++)   {
 395                 ret = rmi_register_function_handler(fn_handlers[i]);
 396                 if (ret) {
 397                         pr_err("%s: error registering the RMI F%02x handler: %d\n",
 398                                 __func__, fn_handlers[i]->func, ret);
 399                         goto err_unregister_function_handlers;
 400                 }
 401         }
 402
 403         return 0;
 404
 405 err_unregister_function_handlers:
 406         __rmi_unregister_function_handlers(i - 1);
 407         return ret;
 408 }
 409
 410 int rmi_of_property_read_u32(struct device *dev, u32 *result,
 411                                 const char *prop, bool optional)
 412 {
 413         int retval;
 414         u32 val = 0;
 415
 416         retval = of_property_read_u32(dev->of_node, prop, &val);
 417         if (retval && (!optional && retval == -EINVAL)) {
 418                 dev_err(dev, "Failed to get %s value: %d\n",
 419                         prop, retval);
 420                 return retval;
 421         }
 422         *result = val;
 423
 424         return 0;
 425 }
 426 EXPORT_SYMBOL_GPL(rmi_of_property_read_u32);
 427
 428 static int __init rmi_bus_init(void)
 429 {
 430         int error;
 431
 432         error = bus_register(&rmi_bus_type);
 433         if (error) {
 434                 pr_err("%s: error registering the RMI bus: %d\n",
 435                         __func__, error);
 436                 return error;
 437         }
 438
 439         error = rmi_register_function_handlers();
 440         if (error)
 441                 goto err_unregister_bus;
 442
 443         error = rmi_register_physical_driver();
 444         if (error) {
 445                 pr_err("%s: error registering the RMI physical driver: %d\n",
 446                         __func__, error);
 447                 goto err_unregister_bus;
 448         }
 449
 450         return 0;
 451
 452 err_unregister_bus:
 453         bus_unregister(&rmi_bus_type);
 454         return error;
 455 }
 456 module_init(rmi_bus_init);
 457
 458 static void __exit rmi_bus_exit(void)
 459 {
 460         /*
 461          * We should only ever get here if all drivers are unloaded, so
 462          * all we have to do at this point is unregister ourselves.
 463          */
 464
 465         rmi_unregister_physical_driver();
 466         rmi_unregister_function_handlers();
 467         bus_unregister(&rmi_bus_type);
 468 }
 469 module_exit(rmi_bus_exit);
 470
 471 MODULE_AUTHOR("Christopher Heiny <[email protected]");
 472 MODULE_AUTHOR("Andrew Duggan <[email protected]");
 473 MODULE_DESCRIPTION("RMI bus");
 474 MODULE_LICENSE("GPL");