1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2015 - 2016 Red Hat, Inc 4 * Copyright (c) 2011, 2012 Synaptics Incorporated 5 * Copyright (c) 2011 Unixphere 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/delay.h> 10 #include <linux/i2c.h> 11 #include <linux/interrupt.h> 12 #include <linux/kconfig.h> 13 #include <linux/lockdep.h> 14 #include <linux/module.h> 15 #include <linux/pm.h> 16 #include <linux/rmi.h> 17 #include <linux/slab.h> 18 #include "rmi_driver.h" 19 20 #define SMB_PROTOCOL_VERSION_ADDRESS 0xfd 21 #define SMB_MAX_COUNT 32 22 #define RMI_SMB2_MAP_SIZE 8 /* 8 entry of 4 bytes each */ 23 #define RMI_SMB2_MAP_FLAGS_WE 0x01 24 25 struct mapping_table_entry { 26 __le16 rmiaddr; 27 u8 readcount; 28 u8 flags; 29 }; 30 31 struct rmi_smb_xport { 32 struct rmi_transport_dev xport; 33 struct i2c_client *client; 34 35 struct mutex page_mutex; 36 int page; 37 u8 table_index; 38 struct mutex mappingtable_mutex; 39 struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE]; 40 }; 41 42 static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb) 43 { 44 struct i2c_client *client = rmi_smb->client; 45 int retval; 46 47 /* Check if for SMBus new version device by reading version byte. */ 48 retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS); 49 if (retval < 0) { 50 dev_err(&client->dev, "failed to get SMBus version number!\n"); 51 return retval; 52 } 53 54 return retval + 1; 55 } 56 57 /* SMB block write - wrapper over ic2_smb_write_block */ 58 static int smb_block_write(struct rmi_transport_dev *xport, 59 u8 commandcode, const void *buf, size_t len) 60 { 61 struct rmi_smb_xport *rmi_smb = 62 container_of(xport, struct rmi_smb_xport, xport); 63 struct i2c_client *client = rmi_smb->client; 64 int retval; 65 66 retval = i2c_smbus_write_block_data(client, commandcode, len, buf); 67 68 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, 69 "wrote %zd bytes at %#04x: %d (%*ph)\n", 70 len, commandcode, retval, (int)len, buf); 71 72 return retval; 73 } 74 75 /* 76 * The function to get command code for smbus operations and keeps 77 * records to the driver mapping table 78 */ 79 static int rmi_smb_get_command_code(struct rmi_transport_dev *xport, 80 u16 rmiaddr, int bytecount, bool isread, u8 *commandcode) 81 { 82 struct rmi_smb_xport *rmi_smb = 83 container_of(xport, struct rmi_smb_xport, xport); 84 struct mapping_table_entry new_map; 85 int i; 86 int retval = 0; 87 88 mutex_lock(&rmi_smb->mappingtable_mutex); 89 90 for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) { 91 struct mapping_table_entry *entry = &rmi_smb->mapping_table[i]; 92 93 if (le16_to_cpu(entry->rmiaddr) == rmiaddr) { 94 if (isread) { 95 if (entry->readcount == bytecount) 96 goto exit; 97 } else { 98 if (entry->flags & RMI_SMB2_MAP_FLAGS_WE) { 99 goto exit; 100 } 101 } 102 } 103 } 104 105 i = rmi_smb->table_index; 106 rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE; 107 108 /* constructs mapping table data entry. 4 bytes each entry */ 109 memset(&new_map, 0, sizeof(new_map)); 110 new_map.rmiaddr = cpu_to_le16(rmiaddr); 111 new_map.readcount = bytecount; 112 new_map.flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0; 113 114 retval = smb_block_write(xport, i + 0x80, &new_map, sizeof(new_map)); 115 if (retval < 0) { 116 /* 117 * if not written to device mapping table 118 * clear the driver mapping table records 119 */ 120 memset(&new_map, 0, sizeof(new_map)); 121 } 122 123 /* save to the driver level mapping table */ 124 rmi_smb->mapping_table[i] = new_map; 125 126 exit: 127 mutex_unlock(&rmi_smb->mappingtable_mutex); 128 129 if (retval < 0) 130 return retval; 131 132 *commandcode = i; 133 return 0; 134 } 135 136 static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr, 137 const void *databuff, size_t len) 138 { 139 int retval = 0; 140 u8 commandcode; 141 struct rmi_smb_xport *rmi_smb = 142 container_of(xport, struct rmi_smb_xport, xport); 143 int cur_len = (int)len; 144 145 mutex_lock(&rmi_smb->page_mutex); 146 147 while (cur_len > 0) { 148 /* 149 * break into 32 bytes chunks to write get command code 150 */ 151 int block_len = min_t(int, len, SMB_MAX_COUNT); 152 153 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len, 154 false, &commandcode); 155 if (retval < 0) 156 goto exit; 157 158 retval = smb_block_write(xport, commandcode, 159 databuff, block_len); 160 if (retval < 0) 161 goto exit; 162 163 /* prepare to write next block of bytes */ 164 cur_len -= SMB_MAX_COUNT; 165 databuff += SMB_MAX_COUNT; 166 rmiaddr += SMB_MAX_COUNT; 167 } 168 exit: 169 mutex_unlock(&rmi_smb->page_mutex); 170 return retval; 171 } 172 173 /* SMB block read - wrapper over ic2_smb_read_block */ 174 static int smb_block_read(struct rmi_transport_dev *xport, 175 u8 commandcode, void *buf, size_t len) 176 { 177 struct rmi_smb_xport *rmi_smb = 178 container_of(xport, struct rmi_smb_xport, xport); 179 struct i2c_client *client = rmi_smb->client; 180 int retval; 181 182 retval = i2c_smbus_read_block_data(client, commandcode, buf); 183 if (retval < 0) 184 return retval; 185 186 return retval; 187 } 188 189 static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr, 190 void *databuff, size_t len) 191 { 192 struct rmi_smb_xport *rmi_smb = 193 container_of(xport, struct rmi_smb_xport, xport); 194 int retval; 195 u8 commandcode; 196 int cur_len = (int)len; 197 198 mutex_lock(&rmi_smb->page_mutex); 199 memset(databuff, 0, len); 200 201 while (cur_len > 0) { 202 /* break into 32 bytes chunks to write get command code */ 203 int block_len = min_t(int, cur_len, SMB_MAX_COUNT); 204 205 retval = rmi_smb_get_command_code(xport, rmiaddr, block_len, 206 true, &commandcode); 207 if (retval < 0) 208 goto exit; 209 210 retval = smb_block_read(xport, commandcode, 211 databuff, block_len); 212 if (retval < 0) 213 goto exit; 214 215 /* prepare to read next block of bytes */ 216 cur_len -= SMB_MAX_COUNT; 217 databuff += SMB_MAX_COUNT; 218 rmiaddr += SMB_MAX_COUNT; 219 } 220 221 retval = 0; 222 223 exit: 224 mutex_unlock(&rmi_smb->page_mutex); 225 return retval; 226 } 227 228 static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb) 229 { 230 /* the mapping table has been flushed, discard the current one */ 231 mutex_lock(&rmi_smb->mappingtable_mutex); 232 memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table)); 233 mutex_unlock(&rmi_smb->mappingtable_mutex); 234 } 235 236 static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb) 237 { 238 int retval; 239 240 /* we need to get the smbus version to activate the touchpad */ 241 retval = rmi_smb_get_version(rmi_smb); 242 if (retval < 0) 243 return retval; 244 245 return 0; 246 } 247 248 static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr) 249 { 250 struct rmi_smb_xport *rmi_smb = 251 container_of(xport, struct rmi_smb_xport, xport); 252 253 rmi_smb_clear_state(rmi_smb); 254 255 /* 256 * we do not call the actual reset command, it has to be handled in 257 * PS/2 or there will be races between PS/2 and SMBus. 258 * PS/2 should ensure that a psmouse_reset is called before 259 * intializing the device and after it has been removed to be in a known 260 * state. 261 */ 262 return rmi_smb_enable_smbus_mode(rmi_smb); 263 } 264 265 static const struct rmi_transport_ops rmi_smb_ops = { 266 .write_block = rmi_smb_write_block, 267 .read_block = rmi_smb_read_block, 268 .reset = rmi_smb_reset, 269 }; 270 271 static int rmi_smb_probe(struct i2c_client *client, 272 const struct i2c_device_id *id) 273 { 274 struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev); 275 struct rmi_smb_xport *rmi_smb; 276 int smbus_version; 277 int error; 278 279 if (!pdata) { 280 dev_err(&client->dev, "no platform data, aborting\n"); 281 return -ENOMEM; 282 } 283 284 if (!i2c_check_functionality(client->adapter, 285 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 286 I2C_FUNC_SMBUS_HOST_NOTIFY)) { 287 dev_err(&client->dev, 288 "adapter does not support required functionality\n"); 289 return -ENODEV; 290 } 291 292 if (client->irq <= 0) { 293 dev_err(&client->dev, "no IRQ provided, giving up\n"); 294 return client->irq ? client->irq : -ENODEV; 295 } 296 297 rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport), 298 GFP_KERNEL); 299 if (!rmi_smb) 300 return -ENOMEM; 301 302 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s\n", 303 dev_name(&client->dev)); 304 305 rmi_smb->client = client; 306 mutex_init(&rmi_smb->page_mutex); 307 mutex_init(&rmi_smb->mappingtable_mutex); 308 309 rmi_smb->xport.dev = &client->dev; 310 rmi_smb->xport.pdata = *pdata; 311 rmi_smb->xport.pdata.irq = client->irq; 312 rmi_smb->xport.proto_name = "smb"; 313 rmi_smb->xport.ops = &rmi_smb_ops; 314 315 smbus_version = rmi_smb_get_version(rmi_smb); 316 if (smbus_version < 0) 317 return smbus_version; 318 319 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d", 320 smbus_version); 321 322 if (smbus_version != 2 && smbus_version != 3) { 323 dev_err(&client->dev, "Unrecognized SMB version %d\n", 324 smbus_version); 325 return -ENODEV; 326 } 327 328 i2c_set_clientdata(client, rmi_smb); 329 330 dev_info(&client->dev, "registering SMbus-connected sensor\n"); 331 332 error = rmi_register_transport_device(&rmi_smb->xport); 333 if (error) { 334 dev_err(&client->dev, "failed to register sensor: %d\n", error); 335 return error; 336 } 337 338 return 0; 339 } 340 341 static int rmi_smb_remove(struct i2c_client *client) 342 { 343 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client); 344 345 rmi_unregister_transport_device(&rmi_smb->xport); 346 347 return 0; 348 } 349 350 static int __maybe_unused rmi_smb_suspend(struct device *dev) 351 { 352 struct i2c_client *client = to_i2c_client(dev); 353 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client); 354 int ret; 355 356 ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, true); 357 if (ret) 358 dev_warn(dev, "Failed to suspend device: %d\n", ret); 359 360 return ret; 361 } 362 363 static int __maybe_unused rmi_smb_runtime_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, false); 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_resume(struct device *dev) 377 { 378 struct i2c_client *client = container_of(dev, struct i2c_client, dev); 379 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client); 380 struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev; 381 int ret; 382 383 rmi_smb_reset(&rmi_smb->xport, 0); 384 385 rmi_reset(rmi_dev); 386 387 ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, true); 388 if (ret) 389 dev_warn(dev, "Failed to resume device: %d\n", ret); 390 391 return 0; 392 } 393 394 static int __maybe_unused rmi_smb_runtime_resume(struct device *dev) 395 { 396 struct i2c_client *client = to_i2c_client(dev); 397 struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client); 398 int ret; 399 400 ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, false); 401 if (ret) 402 dev_warn(dev, "Failed to resume device: %d\n", ret); 403 404 return 0; 405 } 406 407 static const struct dev_pm_ops rmi_smb_pm = { 408 SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, rmi_smb_resume) 409 SET_RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume, 410 NULL) 411 }; 412 413 static const struct i2c_device_id rmi_id[] = { 414 { "rmi4_smbus", 0 }, 415 { } 416 }; 417 MODULE_DEVICE_TABLE(i2c, rmi_id); 418 419 static struct i2c_driver rmi_smb_driver = { 420 .driver = { 421 .name = "rmi4_smbus", 422 .pm = &rmi_smb_pm, 423 }, 424 .id_table = rmi_id, 425 .probe = rmi_smb_probe, 426 .remove = rmi_smb_remove, 427 }; 428 429 module_i2c_driver(rmi_smb_driver); 430 431 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>"); 432 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>"); 433 MODULE_DESCRIPTION("RMI4 SMBus driver"); 434 MODULE_LICENSE("GPL"); 435