drivers/input/rmi4/rmi_smbus.c

   1 /*
   2  * Copyright (c) 2015 - 2016 Red Hat, Inc
   3  * Copyright (c) 2011, 2012 Synaptics Incorporated
   4  * Copyright (c) 2011 Unixphere
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/delay.h>
  13 #include <linux/i2c.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/kconfig.h>
  16 #include <linux/lockdep.h>
  17 #include <linux/module.h>
  18 #include <linux/pm.h>
  19 #include <linux/rmi.h>
  20 #include <linux/slab.h>
  21 #include "rmi_driver.h"
  22
  23 #define SMB_PROTOCOL_VERSION_ADDRESS    0xfd
  24 #define SMB_MAX_COUNT                   32
  25 #define RMI_SMB2_MAP_SIZE               8 /* 8 entry of 4 bytes each */
  26 #define RMI_SMB2_MAP_FLAGS_WE           0x01
  27
  28 struct mapping_table_entry {
  29         __le16 rmiaddr;
  30         u8 readcount;
  31         u8 flags;
  32 };
  33
  34 struct rmi_smb_xport {
  35         struct rmi_transport_dev xport;
  36         struct i2c_client *client;
  37
  38         struct mutex page_mutex;
  39         int page;
  40         u8 table_index;
  41         struct mutex mappingtable_mutex;
  42         struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE];
  43 };
  44
  45 static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb)
  46 {
  47         struct i2c_client *client = rmi_smb->client;
  48         int retval;
  49
  50         /* Check if for SMBus new version device by reading version byte. */
  51         retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS);
  52         if (retval < 0) {
  53                 dev_err(&client->dev, "failed to get SMBus version number!\n");
  54                 return retval;
  55         }
  56         return retval + 1;
  57 }
  58
  59 /* SMB block write - wrapper over ic2_smb_write_block */
  60 static int smb_block_write(struct rmi_transport_dev *xport,
  61                               u8 commandcode, const void *buf, size_t len)
  62 {
  63         struct rmi_smb_xport *rmi_smb =
  64                 container_of(xport, struct rmi_smb_xport, xport);
  65         struct i2c_client *client = rmi_smb->client;
  66         int retval;
  67
  68         retval = i2c_smbus_write_block_data(client, commandcode, len, buf);
  69
  70         rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
  71                 "wrote %zd bytes at %#04x: %d (%*ph)\n",
  72                 len, commandcode, retval, (int)len, buf);
  73
  74         return retval;
  75 }
  76
  77 /*
  78  * The function to get command code for smbus operations and keeps
  79  * records to the driver mapping table
  80  */
  81 static int rmi_smb_get_command_code(struct rmi_transport_dev *xport,
  82                 u16 rmiaddr, int bytecount, bool isread, u8 *commandcode)
  83 {
  84         struct rmi_smb_xport *rmi_smb =
  85                 container_of(xport, struct rmi_smb_xport, xport);
  86         int i;
  87         int retval;
  88         struct mapping_table_entry mapping_data[1];
  89
  90         mutex_lock(&rmi_smb->mappingtable_mutex);
  91         for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) {
  92                 struct mapping_table_entry *entry = &rmi_smb->mapping_table[i];
  93
  94                 if (le16_to_cpu(entry->rmiaddr) == rmiaddr) {
  95                         if (isread) {
  96                                 if (entry->readcount == bytecount) {
  97                                         *commandcode = i;
  98                                         retval = 0;
  99                                         goto exit;
 100                                 }
 101                         } else {
 102                                 if (entry->flags & RMI_SMB2_MAP_FLAGS_WE) {
 103                                         *commandcode = i;
 104                                         retval = 0;
 105                                         goto exit;
 106                                 }
 107                         }
 108                 }
 109         }
 110         i = rmi_smb->table_index;
 111         rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE;
 112
 113         /* constructs mapping table data entry. 4 bytes each entry */
 114         memset(mapping_data, 0, sizeof(mapping_data));
 115
 116         mapping_data[0].rmiaddr = cpu_to_le16(rmiaddr);
 117         mapping_data[0].readcount = bytecount;
 118         mapping_data[0].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
 119
 120         retval = smb_block_write(xport, i + 0x80, mapping_data,
 121                                  sizeof(mapping_data));
 122
 123         if (retval < 0) {
 124                 /*
 125                  * if not written to device mapping table
 126                  * clear the driver mapping table records
 127                  */
 128                 rmi_smb->mapping_table[i].rmiaddr = 0x0000;
 129                 rmi_smb->mapping_table[i].readcount = 0;
 130                 rmi_smb->mapping_table[i].flags = 0;
 131                 goto exit;
 132         }
 133         /* save to the driver level mapping table */
 134         rmi_smb->mapping_table[i].rmiaddr = rmiaddr;
 135         rmi_smb->mapping_table[i].readcount = bytecount;
 136         rmi_smb->mapping_table[i].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
 137         *commandcode = i;
 138
 139 exit:
 140         mutex_unlock(&rmi_smb->mappingtable_mutex);
 141
 142         return retval;
 143 }
 144
 145 static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr,
 146                                 const void *databuff, size_t len)
 147 {
 148         int retval = 0;
 149         u8 commandcode;
 150         struct rmi_smb_xport *rmi_smb =
 151                 container_of(xport, struct rmi_smb_xport, xport);
 152         int cur_len = (int)len;
 153
 154         mutex_lock(&rmi_smb->page_mutex);
 155
 156         while (cur_len > 0) {
 157                 /*
 158                  * break into 32 bytes chunks to write get command code
 159                  */
 160                 int block_len = min_t(int, len, SMB_MAX_COUNT);
 161
 162                 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
 163                                                   false, &commandcode);
 164                 if (retval < 0)
 165                         goto exit;
 166
 167                 retval = smb_block_write(xport, commandcode,
 168                                          databuff, block_len);
 169                 if (retval < 0)
 170                         goto exit;
 171
 172                 /* prepare to write next block of bytes */
 173                 cur_len -= SMB_MAX_COUNT;
 174                 databuff += SMB_MAX_COUNT;
 175                 rmiaddr += SMB_MAX_COUNT;
 176         }
 177 exit:
 178         mutex_unlock(&rmi_smb->page_mutex);
 179         return retval;
 180 }
 181
 182 /* SMB block read - wrapper over ic2_smb_read_block */
 183 static int smb_block_read(struct rmi_transport_dev *xport,
 184                              u8 commandcode, void *buf, size_t len)
 185 {
 186         struct rmi_smb_xport *rmi_smb =
 187                 container_of(xport, struct rmi_smb_xport, xport);
 188         struct i2c_client *client = rmi_smb->client;
 189         int retval;
 190
 191         retval = i2c_smbus_read_block_data(client, commandcode, buf);
 192         if (retval < 0)
 193                 return retval;
 194
 195         return retval;
 196 }
 197
 198 static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr,
 199                               void *databuff, size_t len)
 200 {
 201         struct rmi_smb_xport *rmi_smb =
 202                 container_of(xport, struct rmi_smb_xport, xport);
 203         int retval;
 204         u8 commandcode;
 205         int cur_len = (int)len;
 206
 207         mutex_lock(&rmi_smb->page_mutex);
 208         memset(databuff, 0, len);
 209
 210         while (cur_len > 0) {
 211                 /* break into 32 bytes chunks to write get command code */
 212                 int block_len =  min_t(int, cur_len, SMB_MAX_COUNT);
 213
 214                 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
 215                                                   true, &commandcode);
 216                 if (retval < 0)
 217                         goto exit;
 218
 219                 retval = smb_block_read(xport, commandcode,
 220                                         databuff, block_len);
 221                 if (retval < 0)
 222                         goto exit;
 223
 224                 /* prepare to read next block of bytes */
 225                 cur_len -= SMB_MAX_COUNT;
 226                 databuff += SMB_MAX_COUNT;
 227                 rmiaddr += SMB_MAX_COUNT;
 228         }
 229
 230         retval = 0;
 231
 232 exit:
 233         mutex_unlock(&rmi_smb->page_mutex);
 234         return retval;
 235 }
 236
 237 static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb)
 238 {
 239         /* the mapping table has been flushed, discard the current one */
 240         mutex_lock(&rmi_smb->mappingtable_mutex);
 241         memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table));
 242         mutex_unlock(&rmi_smb->mappingtable_mutex);
 243 }
 244
 245 static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb)
 246 {
 247         int retval;
 248
 249         /* we need to get the smbus version to activate the touchpad */
 250         retval = rmi_smb_get_version(rmi_smb);
 251         if (retval < 0)
 252                 return retval;
 253
 254         return 0;
 255 }
 256
 257 static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr)
 258 {
 259         struct rmi_smb_xport *rmi_smb =
 260                 container_of(xport, struct rmi_smb_xport, xport);
 261
 262         rmi_smb_clear_state(rmi_smb);
 263
 264         /*
 265          * we do not call the actual reset command, it has to be handled in
 266          * PS/2 or there will be races between PS/2 and SMBus.
 267          * PS/2 should ensure that a psmouse_reset is called before
 268          * intializing the device and after it has been removed to be in a known
 269          * state.
 270          */
 271         return rmi_smb_enable_smbus_mode(rmi_smb);
 272 }
 273
 274 static const struct rmi_transport_ops rmi_smb_ops = {
 275         .write_block    = rmi_smb_write_block,
 276         .read_block     = rmi_smb_read_block,
 277         .reset          = rmi_smb_reset,
 278 };
 279
 280 static int rmi_smb_probe(struct i2c_client *client,
 281                          const struct i2c_device_id *id)
 282 {
 283         struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev);
 284         struct rmi_smb_xport *rmi_smb;
 285         int retval;
 286         int smbus_version;
 287
 288         if (!i2c_check_functionality(client->adapter,
 289                                      I2C_FUNC_SMBUS_READ_BLOCK_DATA |
 290                                      I2C_FUNC_SMBUS_HOST_NOTIFY)) {
 291                 dev_err(&client->dev,
 292                         "adapter does not support required functionality.\n");
 293                 return -ENODEV;
 294         }
 295
 296         if (client->irq <= 0) {
 297                 dev_err(&client->dev, "no IRQ provided, giving up.\n");
 298                 return client->irq ? client->irq : -ENODEV;
 299         }
 300
 301         rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport),
 302                                 GFP_KERNEL);
 303         if (!rmi_smb)
 304                 return -ENOMEM;
 305
 306         if (!pdata) {
 307                 dev_err(&client->dev, "no platform data, aborting\n");
 308                 return -ENOMEM;
 309         }
 310
 311         rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
 312                 dev_name(&client->dev));
 313
 314         rmi_smb->client = client;
 315         mutex_init(&rmi_smb->page_mutex);
 316         mutex_init(&rmi_smb->mappingtable_mutex);
 317
 318         rmi_smb->xport.dev = &client->dev;
 319         rmi_smb->xport.pdata = *pdata;
 320         rmi_smb->xport.pdata.irq = client->irq;
 321         rmi_smb->xport.proto_name = "smb2";
 322         rmi_smb->xport.ops = &rmi_smb_ops;
 323
 324         retval = rmi_smb_get_version(rmi_smb);
 325         if (retval < 0)
 326                 return retval;
 327
 328         smbus_version = retval;
 329         rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d",
 330                 smbus_version);
 331
 332         if (smbus_version != 2) {
 333                 dev_err(&client->dev, "Unrecognized SMB version %d.\n",
 334                                 smbus_version);
 335                 return -ENODEV;
 336         }
 337
 338         i2c_set_clientdata(client, rmi_smb);
 339
 340         retval = rmi_register_transport_device(&rmi_smb->xport);
 341         if (retval) {
 342                 dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
 343                         client->addr);
 344                 i2c_set_clientdata(client, NULL);
 345                 return retval;
 346         }
 347
 348         dev_info(&client->dev, "registered rmi smb driver at %#04x.\n",
 349                         client->addr);
 350         return 0;
 351
 352 }
 353
 354 static int rmi_smb_remove(struct i2c_client *client)
 355 {
 356         struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
 357
 358         rmi_unregister_transport_device(&rmi_smb->xport);
 359
 360         return 0;
 361 }
 362
 363 static int __maybe_unused rmi_smb_suspend(struct device *dev)
 364 {
 365         struct i2c_client *client = to_i2c_client(dev);
 366         struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
 367         int ret;
 368
 369         ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, true);
 370         if (ret)
 371                 dev_warn(dev, "Failed to suspend device: %d\n", ret);
 372
 373         return ret;
 374 }
 375
 376 static int __maybe_unused rmi_smb_runtime_suspend(struct device *dev)
 377 {
 378         struct i2c_client *client = to_i2c_client(dev);
 379         struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
 380         int ret;
 381
 382         ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, false);
 383         if (ret)
 384                 dev_warn(dev, "Failed to suspend device: %d\n", ret);
 385
 386         return ret;
 387 }
 388
 389 static int __maybe_unused rmi_smb_resume(struct device *dev)
 390 {
 391         struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 392         struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
 393         struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
 394         int ret;
 395
 396         rmi_smb_reset(&rmi_smb->xport, 0);
 397
 398         rmi_reset(rmi_dev);
 399
 400         ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, true);
 401         if (ret)
 402                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 403
 404         return 0;
 405 }
 406
 407 static int __maybe_unused rmi_smb_runtime_resume(struct device *dev)
 408 {
 409         struct i2c_client *client = to_i2c_client(dev);
 410         struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
 411         int ret;
 412
 413         ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, false);
 414         if (ret)
 415                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 416
 417         return 0;
 418 }
 419
 420 static const struct dev_pm_ops rmi_smb_pm = {
 421         SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, rmi_smb_resume)
 422         SET_RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume,
 423                            NULL)
 424 };
 425
 426 static const struct i2c_device_id rmi_id[] = {
 427         { "rmi4_smbus", 0 },
 428         { }
 429 };
 430 MODULE_DEVICE_TABLE(i2c, rmi_id);
 431
 432 static struct i2c_driver rmi_smb_driver = {
 433         .driver = {
 434                 .name   = "rmi4_smbus",
 435                 .pm     = &rmi_smb_pm,
 436         },
 437         .id_table       = rmi_id,
 438         .probe          = rmi_smb_probe,
 439         .remove         = rmi_smb_remove,
 440 };
 441
 442 module_i2c_driver(rmi_smb_driver);
 443
 444 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
 445 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
 446 MODULE_DESCRIPTION("RMI4 SMBus driver");
 447 MODULE_LICENSE("GPL");