drivers/input/rmi4/rmi_i2c.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/i2c.h>
  11 #include <linux/rmi.h>
  12 #include <linux/irq.h>
  13 #include <linux/of.h>
  14 #include <linux/delay.h>
  15 #include <linux/regulator/consumer.h>
  16 #include "rmi_driver.h"
  17
  18 #define BUFFER_SIZE_INCREMENT 32
  19
  20 /**
  21  * struct rmi_i2c_xport - stores information for i2c communication
  22  *
  23  * @xport: The transport interface structure
  24  *
  25  * @page_mutex: Locks current page to avoid changing pages in unexpected ways.
  26  * @page: Keeps track of the current virtual page
  27  *
  28  * @tx_buf: Buffer used for transmitting data to the sensor over i2c.
  29  * @tx_buf_size: Size of the buffer
  30  */
  31 struct rmi_i2c_xport {
  32         struct rmi_transport_dev xport;
  33         struct i2c_client *client;
  34
  35         struct mutex page_mutex;
  36         int page;
  37
  38         int irq;
  39
  40         u8 *tx_buf;
  41         size_t tx_buf_size;
  42
  43         struct regulator_bulk_data supplies[2];
  44         u32 startup_delay;
  45 };
  46
  47 #define RMI_PAGE_SELECT_REGISTER 0xff
  48 #define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff)
  49
  50 /*
  51  * rmi_set_page - Set RMI page
  52  * @xport: The pointer to the rmi_transport_dev struct
  53  * @page: The new page address.
  54  *
  55  * RMI devices have 16-bit addressing, but some of the transport
  56  * implementations (like SMBus) only have 8-bit addressing. So RMI implements
  57  * a page address at 0xff of every page so we can reliable page addresses
  58  * every 256 registers.
  59  *
  60  * The page_mutex lock must be held when this function is entered.
  61  *
  62  * Returns zero on success, non-zero on failure.
  63  */
  64 static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page)
  65 {
  66         struct i2c_client *client = rmi_i2c->client;
  67         u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page};
  68         int retval;
  69
  70         retval = i2c_master_send(client, txbuf, sizeof(txbuf));
  71         if (retval != sizeof(txbuf)) {
  72                 dev_err(&client->dev,
  73                         "%s: set page failed: %d.", __func__, retval);
  74                 return (retval < 0) ? retval : -EIO;
  75         }
  76
  77         rmi_i2c->page = page;
  78         return 0;
  79 }
  80
  81 static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr,
  82                                const void *buf, size_t len)
  83 {
  84         struct rmi_i2c_xport *rmi_i2c =
  85                 container_of(xport, struct rmi_i2c_xport, xport);
  86         struct i2c_client *client = rmi_i2c->client;
  87         size_t tx_size = len + 1;
  88         int retval;
  89
  90         mutex_lock(&rmi_i2c->page_mutex);
  91
  92         if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) {
  93                 if (rmi_i2c->tx_buf)
  94                         devm_kfree(&client->dev, rmi_i2c->tx_buf);
  95                 rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT;
  96                 rmi_i2c->tx_buf = devm_kzalloc(&client->dev,
  97                                                rmi_i2c->tx_buf_size,
  98                                                GFP_KERNEL);
  99                 if (!rmi_i2c->tx_buf) {
 100                         rmi_i2c->tx_buf_size = 0;
 101                         retval = -ENOMEM;
 102                         goto exit;
 103                 }
 104         }
 105
 106         rmi_i2c->tx_buf[0] = addr & 0xff;
 107         memcpy(rmi_i2c->tx_buf + 1, buf, len);
 108
 109         if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
 110                 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
 111                 if (retval)
 112                         goto exit;
 113         }
 114
 115         retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
 116         if (retval == tx_size)
 117                 retval = 0;
 118         else if (retval >= 0)
 119                 retval = -EIO;
 120
 121 exit:
 122         rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
 123                 "write %zd bytes at %#06x: %d (%*ph)\n",
 124                 len, addr, retval, (int)len, buf);
 125
 126         mutex_unlock(&rmi_i2c->page_mutex);
 127         return retval;
 128 }
 129
 130 static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr,
 131                               void *buf, size_t len)
 132 {
 133         struct rmi_i2c_xport *rmi_i2c =
 134                 container_of(xport, struct rmi_i2c_xport, xport);
 135         struct i2c_client *client = rmi_i2c->client;
 136         u8 addr_offset = addr & 0xff;
 137         int retval;
 138         struct i2c_msg msgs[] = {
 139                 {
 140                         .addr   = client->addr,
 141                         .len    = sizeof(addr_offset),
 142                         .buf    = &addr_offset,
 143                 },
 144                 {
 145                         .addr   = client->addr,
 146                         .flags  = I2C_M_RD,
 147                         .len    = len,
 148                         .buf    = buf,
 149                 },
 150         };
 151
 152         mutex_lock(&rmi_i2c->page_mutex);
 153
 154         if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
 155                 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
 156                 if (retval)
 157                         goto exit;
 158         }
 159
 160         retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 161         if (retval == ARRAY_SIZE(msgs))
 162                 retval = 0; /* success */
 163         else if (retval >= 0)
 164                 retval = -EIO;
 165
 166 exit:
 167         rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
 168                 "read %zd bytes at %#06x: %d (%*ph)\n",
 169                 len, addr, retval, (int)len, buf);
 170
 171         mutex_unlock(&rmi_i2c->page_mutex);
 172         return retval;
 173 }
 174
 175 static const struct rmi_transport_ops rmi_i2c_ops = {
 176         .write_block    = rmi_i2c_write_block,
 177         .read_block     = rmi_i2c_read_block,
 178 };
 179
 180 static irqreturn_t rmi_i2c_irq(int irq, void *dev_id)
 181 {
 182         struct rmi_i2c_xport *rmi_i2c = dev_id;
 183         struct rmi_device *rmi_dev = rmi_i2c->xport.rmi_dev;
 184         int ret;
 185
 186         ret = rmi_process_interrupt_requests(rmi_dev);
 187         if (ret)
 188                 rmi_dbg(RMI_DEBUG_XPORT, &rmi_dev->dev,
 189                         "Failed to process interrupt request: %d\n", ret);
 190
 191         return IRQ_HANDLED;
 192 }
 193
 194 static int rmi_i2c_init_irq(struct i2c_client *client)
 195 {
 196         struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
 197         int irq_flags = irqd_get_trigger_type(irq_get_irq_data(rmi_i2c->irq));
 198         int ret;
 199
 200         if (!irq_flags)
 201                 irq_flags = IRQF_TRIGGER_LOW;
 202
 203         ret = devm_request_threaded_irq(&client->dev, rmi_i2c->irq, NULL,
 204                         rmi_i2c_irq, irq_flags | IRQF_ONESHOT, client->name,
 205                         rmi_i2c);
 206         if (ret < 0) {
 207                 dev_warn(&client->dev, "Failed to register interrupt %d\n",
 208                         rmi_i2c->irq);
 209
 210                 return ret;
 211         }
 212
 213         return 0;
 214 }
 215
 216 #ifdef CONFIG_OF
 217 static const struct of_device_id rmi_i2c_of_match[] = {
 218         { .compatible = "syna,rmi4-i2c" },
 219         {},
 220 };
 221 MODULE_DEVICE_TABLE(of, rmi_i2c_of_match);
 222 #endif
 223
 224 static void rmi_i2c_regulator_bulk_disable(void *data)
 225 {
 226         struct rmi_i2c_xport *rmi_i2c = data;
 227
 228         regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
 229                                rmi_i2c->supplies);
 230 }
 231
 232 static void rmi_i2c_unregister_transport(void *data)
 233 {
 234         struct rmi_i2c_xport *rmi_i2c = data;
 235
 236         rmi_unregister_transport_device(&rmi_i2c->xport);
 237 }
 238
 239 static int rmi_i2c_probe(struct i2c_client *client,
 240                          const struct i2c_device_id *id)
 241 {
 242         struct rmi_device_platform_data *pdata;
 243         struct rmi_device_platform_data *client_pdata =
 244                                         dev_get_platdata(&client->dev);
 245         struct rmi_i2c_xport *rmi_i2c;
 246         int retval;
 247
 248         rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport),
 249                                 GFP_KERNEL);
 250         if (!rmi_i2c)
 251                 return -ENOMEM;
 252
 253         pdata = &rmi_i2c->xport.pdata;
 254
 255         if (!client->dev.of_node && client_pdata)
 256                 *pdata = *client_pdata;
 257
 258         if (client->irq > 0)
 259                 rmi_i2c->irq = client->irq;
 260
 261         rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
 262                         dev_name(&client->dev));
 263         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 264                 dev_err(&client->dev,
 265                         "adapter does not support required functionality.\n");
 266                 return -ENODEV;
 267         }
 268
 269         rmi_i2c->supplies[0].supply = "vdd";
 270         rmi_i2c->supplies[1].supply = "vio";
 271         retval = devm_regulator_bulk_get(&client->dev,
 272                                          ARRAY_SIZE(rmi_i2c->supplies),
 273                                          rmi_i2c->supplies);
 274         if (retval < 0)
 275                 return retval;
 276
 277         retval = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
 278                                        rmi_i2c->supplies);
 279         if (retval < 0)
 280                 return retval;
 281
 282         retval = devm_add_action_or_reset(&client->dev,
 283                                           rmi_i2c_regulator_bulk_disable,
 284                                           rmi_i2c);
 285         if (retval)
 286                 return retval;
 287
 288         of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms",
 289                              &rmi_i2c->startup_delay);
 290
 291         msleep(rmi_i2c->startup_delay);
 292
 293         rmi_i2c->client = client;
 294         mutex_init(&rmi_i2c->page_mutex);
 295
 296         rmi_i2c->xport.dev = &client->dev;
 297         rmi_i2c->xport.proto_name = "i2c";
 298         rmi_i2c->xport.ops = &rmi_i2c_ops;
 299
 300         i2c_set_clientdata(client, rmi_i2c);
 301
 302         /*
 303          * Setting the page to zero will (a) make sure the PSR is in a
 304          * known state, and (b) make sure we can talk to the device.
 305          */
 306         retval = rmi_set_page(rmi_i2c, 0);
 307         if (retval) {
 308                 dev_err(&client->dev, "Failed to set page select to 0.\n");
 309                 return retval;
 310         }
 311
 312         retval = rmi_register_transport_device(&rmi_i2c->xport);
 313         if (retval) {
 314                 dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
 315                         client->addr);
 316                 return retval;
 317         }
 318         retval = devm_add_action_or_reset(&client->dev,
 319                                           rmi_i2c_unregister_transport,
 320                                           rmi_i2c);
 321         if (retval)
 322                 return retval;
 323
 324         retval = rmi_i2c_init_irq(client);
 325         if (retval < 0)
 326                 return retval;
 327
 328         dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n",
 329                         client->addr);
 330         return 0;
 331 }
 332
 333 #ifdef CONFIG_PM_SLEEP
 334 static int rmi_i2c_suspend(struct device *dev)
 335 {
 336         struct i2c_client *client = to_i2c_client(dev);
 337         struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
 338         int ret;
 339
 340         ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev);
 341         if (ret)
 342                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 343
 344         disable_irq(rmi_i2c->irq);
 345         if (device_may_wakeup(&client->dev)) {
 346                 ret = enable_irq_wake(rmi_i2c->irq);
 347                 if (!ret)
 348                         dev_warn(dev, "Failed to enable irq for wake: %d\n",
 349                                 ret);
 350         }
 351
 352         regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
 353                                rmi_i2c->supplies);
 354
 355         return ret;
 356 }
 357
 358 static int rmi_i2c_resume(struct device *dev)
 359 {
 360         struct i2c_client *client = to_i2c_client(dev);
 361         struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
 362         int ret;
 363
 364         ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
 365                                     rmi_i2c->supplies);
 366         if (ret)
 367                 return ret;
 368
 369         msleep(rmi_i2c->startup_delay);
 370
 371         enable_irq(rmi_i2c->irq);
 372         if (device_may_wakeup(&client->dev)) {
 373                 ret = disable_irq_wake(rmi_i2c->irq);
 374                 if (!ret)
 375                         dev_warn(dev, "Failed to disable irq for wake: %d\n",
 376                                 ret);
 377         }
 378
 379         ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
 380         if (ret)
 381                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 382
 383         return ret;
 384 }
 385 #endif
 386
 387 #ifdef CONFIG_PM
 388 static int rmi_i2c_runtime_suspend(struct device *dev)
 389 {
 390         struct i2c_client *client = to_i2c_client(dev);
 391         struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
 392         int ret;
 393
 394         ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev);
 395         if (ret)
 396                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 397
 398         disable_irq(rmi_i2c->irq);
 399
 400         regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
 401                                rmi_i2c->supplies);
 402
 403         return 0;
 404 }
 405
 406 static int rmi_i2c_runtime_resume(struct device *dev)
 407 {
 408         struct i2c_client *client = to_i2c_client(dev);
 409         struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
 410         int ret;
 411
 412         ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
 413                                     rmi_i2c->supplies);
 414         if (ret)
 415                 return ret;
 416
 417         msleep(rmi_i2c->startup_delay);
 418
 419         enable_irq(rmi_i2c->irq);
 420
 421         ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
 422         if (ret)
 423                 dev_warn(dev, "Failed to resume device: %d\n", ret);
 424
 425         return 0;
 426 }
 427 #endif
 428
 429 static const struct dev_pm_ops rmi_i2c_pm = {
 430         SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume)
 431         SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume,
 432                            NULL)
 433 };
 434
 435 static const struct i2c_device_id rmi_id[] = {
 436         { "rmi4_i2c", 0 },
 437         { }
 438 };
 439 MODULE_DEVICE_TABLE(i2c, rmi_id);
 440
 441 static struct i2c_driver rmi_i2c_driver = {
 442         .driver = {
 443                 .name   = "rmi4_i2c",
 444                 .pm     = &rmi_i2c_pm,
 445                 .of_match_table = of_match_ptr(rmi_i2c_of_match),
 446         },
 447         .id_table       = rmi_id,
 448         .probe          = rmi_i2c_probe,
 449 };
 450
 451 module_i2c_driver(rmi_i2c_driver);
 452
 453 MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>");
 454 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
 455 MODULE_DESCRIPTION("RMI I2C driver");
 456 MODULE_LICENSE("GPL");
 457 MODULE_VERSION(RMI_DRIVER_VERSION);