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/i2c.h> 8 #include <linux/rmi.h> 9 #include <linux/of.h> 10 #include <linux/delay.h> 11 #include <linux/regulator/consumer.h> 12 #include "rmi_driver.h" 13 14 #define BUFFER_SIZE_INCREMENT 32 15 16 /** 17 * struct rmi_i2c_xport - stores information for i2c communication 18 * 19 * @xport: The transport interface structure 20 * @client: The I2C client device structure 21 * 22 * @page_mutex: Locks current page to avoid changing pages in unexpected ways. 23 * @page: Keeps track of the current virtual page 24 * 25 * @tx_buf: Buffer used for transmitting data to the sensor over i2c. 26 * @tx_buf_size: Size of the buffer 27 * 28 * @supplies: Array of voltage regulators 29 * @startup_delay: Milliseconds to pause after powering up the regulators 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 u8 *tx_buf; 39 size_t tx_buf_size; 40 41 struct regulator_bulk_data supplies[2]; 42 u32 startup_delay; 43 }; 44 45 #define RMI_PAGE_SELECT_REGISTER 0xff 46 #define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff) 47 48 /* 49 * rmi_set_page - Set RMI page 50 * @xport: The pointer to the rmi_transport_dev struct 51 * @page: The new page address. 52 * 53 * RMI devices have 16-bit addressing, but some of the transport 54 * implementations (like SMBus) only have 8-bit addressing. So RMI implements 55 * a page address at 0xff of every page so we can reliable page addresses 56 * every 256 registers. 57 * 58 * The page_mutex lock must be held when this function is entered. 59 * 60 * Returns zero on success, non-zero on failure. 61 */ 62 static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page) 63 { 64 struct i2c_client *client = rmi_i2c->client; 65 u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page}; 66 int retval; 67 68 retval = i2c_master_send(client, txbuf, sizeof(txbuf)); 69 if (retval != sizeof(txbuf)) { 70 dev_err(&client->dev, 71 "%s: set page failed: %d.", __func__, retval); 72 return (retval < 0) ? retval : -EIO; 73 } 74 75 rmi_i2c->page = page; 76 return 0; 77 } 78 79 static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr, 80 const void *buf, size_t len) 81 { 82 struct rmi_i2c_xport *rmi_i2c = 83 container_of(xport, struct rmi_i2c_xport, xport); 84 struct i2c_client *client = rmi_i2c->client; 85 size_t tx_size = len + 1; 86 int retval; 87 88 mutex_lock(&rmi_i2c->page_mutex); 89 90 if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) { 91 if (rmi_i2c->tx_buf) 92 devm_kfree(&client->dev, rmi_i2c->tx_buf); 93 rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT; 94 rmi_i2c->tx_buf = devm_kzalloc(&client->dev, 95 rmi_i2c->tx_buf_size, 96 GFP_KERNEL); 97 if (!rmi_i2c->tx_buf) { 98 rmi_i2c->tx_buf_size = 0; 99 retval = -ENOMEM; 100 goto exit; 101 } 102 } 103 104 rmi_i2c->tx_buf[0] = addr & 0xff; 105 memcpy(rmi_i2c->tx_buf + 1, buf, len); 106 107 if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { 108 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); 109 if (retval) 110 goto exit; 111 } 112 113 retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size); 114 if (retval == tx_size) 115 retval = 0; 116 else if (retval >= 0) 117 retval = -EIO; 118 119 exit: 120 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, 121 "write %zd bytes at %#06x: %d (%*ph)\n", 122 len, addr, retval, (int)len, buf); 123 124 mutex_unlock(&rmi_i2c->page_mutex); 125 return retval; 126 } 127 128 static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr, 129 void *buf, size_t len) 130 { 131 struct rmi_i2c_xport *rmi_i2c = 132 container_of(xport, struct rmi_i2c_xport, xport); 133 struct i2c_client *client = rmi_i2c->client; 134 u8 addr_offset = addr & 0xff; 135 int retval; 136 struct i2c_msg msgs[] = { 137 { 138 .addr = client->addr, 139 .len = sizeof(addr_offset), 140 .buf = &addr_offset, 141 }, 142 { 143 .addr = client->addr, 144 .flags = I2C_M_RD, 145 .len = len, 146 .buf = buf, 147 }, 148 }; 149 150 mutex_lock(&rmi_i2c->page_mutex); 151 152 if (RMI_I2C_PAGE(addr) != rmi_i2c->page) { 153 retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr)); 154 if (retval) 155 goto exit; 156 } 157 158 retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 159 if (retval == ARRAY_SIZE(msgs)) 160 retval = 0; /* success */ 161 else if (retval >= 0) 162 retval = -EIO; 163 164 exit: 165 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, 166 "read %zd bytes at %#06x: %d (%*ph)\n", 167 len, addr, retval, (int)len, buf); 168 169 mutex_unlock(&rmi_i2c->page_mutex); 170 return retval; 171 } 172 173 static const struct rmi_transport_ops rmi_i2c_ops = { 174 .write_block = rmi_i2c_write_block, 175 .read_block = rmi_i2c_read_block, 176 }; 177 178 #ifdef CONFIG_OF 179 static const struct of_device_id rmi_i2c_of_match[] = { 180 { .compatible = "syna,rmi4-i2c" }, 181 {}, 182 }; 183 MODULE_DEVICE_TABLE(of, rmi_i2c_of_match); 184 #endif 185 186 static void rmi_i2c_regulator_bulk_disable(void *data) 187 { 188 struct rmi_i2c_xport *rmi_i2c = data; 189 190 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), 191 rmi_i2c->supplies); 192 } 193 194 static void rmi_i2c_unregister_transport(void *data) 195 { 196 struct rmi_i2c_xport *rmi_i2c = data; 197 198 rmi_unregister_transport_device(&rmi_i2c->xport); 199 } 200 201 static int rmi_i2c_probe(struct i2c_client *client, 202 const struct i2c_device_id *id) 203 { 204 struct rmi_device_platform_data *pdata; 205 struct rmi_device_platform_data *client_pdata = 206 dev_get_platdata(&client->dev); 207 struct rmi_i2c_xport *rmi_i2c; 208 int error; 209 210 rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport), 211 GFP_KERNEL); 212 if (!rmi_i2c) 213 return -ENOMEM; 214 215 pdata = &rmi_i2c->xport.pdata; 216 217 if (!client->dev.of_node && client_pdata) 218 *pdata = *client_pdata; 219 220 pdata->irq = client->irq; 221 222 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n", 223 dev_name(&client->dev)); 224 225 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 226 dev_err(&client->dev, 227 "adapter does not support required functionality\n"); 228 return -ENODEV; 229 } 230 231 rmi_i2c->supplies[0].supply = "vdd"; 232 rmi_i2c->supplies[1].supply = "vio"; 233 error = devm_regulator_bulk_get(&client->dev, 234 ARRAY_SIZE(rmi_i2c->supplies), 235 rmi_i2c->supplies); 236 if (error < 0) 237 return error; 238 239 error = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), 240 rmi_i2c->supplies); 241 if (error < 0) 242 return error; 243 244 error = devm_add_action_or_reset(&client->dev, 245 rmi_i2c_regulator_bulk_disable, 246 rmi_i2c); 247 if (error) 248 return error; 249 250 of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms", 251 &rmi_i2c->startup_delay); 252 253 msleep(rmi_i2c->startup_delay); 254 255 rmi_i2c->client = client; 256 mutex_init(&rmi_i2c->page_mutex); 257 258 rmi_i2c->xport.dev = &client->dev; 259 rmi_i2c->xport.proto_name = "i2c"; 260 rmi_i2c->xport.ops = &rmi_i2c_ops; 261 262 i2c_set_clientdata(client, rmi_i2c); 263 264 /* 265 * Setting the page to zero will (a) make sure the PSR is in a 266 * known state, and (b) make sure we can talk to the device. 267 */ 268 error = rmi_set_page(rmi_i2c, 0); 269 if (error) { 270 dev_err(&client->dev, "Failed to set page select to 0\n"); 271 return error; 272 } 273 274 dev_info(&client->dev, "registering I2C-connected sensor\n"); 275 276 error = rmi_register_transport_device(&rmi_i2c->xport); 277 if (error) { 278 dev_err(&client->dev, "failed to register sensor: %d\n", error); 279 return error; 280 } 281 282 error = devm_add_action_or_reset(&client->dev, 283 rmi_i2c_unregister_transport, 284 rmi_i2c); 285 if (error) 286 return error; 287 288 return 0; 289 } 290 291 #ifdef CONFIG_PM_SLEEP 292 static int rmi_i2c_suspend(struct device *dev) 293 { 294 struct i2c_client *client = to_i2c_client(dev); 295 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 296 int ret; 297 298 ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true); 299 if (ret) 300 dev_warn(dev, "Failed to resume device: %d\n", ret); 301 302 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), 303 rmi_i2c->supplies); 304 305 return ret; 306 } 307 308 static int rmi_i2c_resume(struct device *dev) 309 { 310 struct i2c_client *client = to_i2c_client(dev); 311 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 312 int ret; 313 314 ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), 315 rmi_i2c->supplies); 316 if (ret) 317 return ret; 318 319 msleep(rmi_i2c->startup_delay); 320 321 ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true); 322 if (ret) 323 dev_warn(dev, "Failed to resume device: %d\n", ret); 324 325 return ret; 326 } 327 #endif 328 329 #ifdef CONFIG_PM 330 static int rmi_i2c_runtime_suspend(struct device *dev) 331 { 332 struct i2c_client *client = to_i2c_client(dev); 333 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 334 int ret; 335 336 ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, false); 337 if (ret) 338 dev_warn(dev, "Failed to resume device: %d\n", ret); 339 340 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), 341 rmi_i2c->supplies); 342 343 return 0; 344 } 345 346 static int rmi_i2c_runtime_resume(struct device *dev) 347 { 348 struct i2c_client *client = to_i2c_client(dev); 349 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 350 int ret; 351 352 ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), 353 rmi_i2c->supplies); 354 if (ret) 355 return ret; 356 357 msleep(rmi_i2c->startup_delay); 358 359 ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, false); 360 if (ret) 361 dev_warn(dev, "Failed to resume device: %d\n", ret); 362 363 return 0; 364 } 365 #endif 366 367 static const struct dev_pm_ops rmi_i2c_pm = { 368 SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume) 369 SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume, 370 NULL) 371 }; 372 373 static const struct i2c_device_id rmi_id[] = { 374 { "rmi4_i2c", 0 }, 375 { } 376 }; 377 MODULE_DEVICE_TABLE(i2c, rmi_id); 378 379 static struct i2c_driver rmi_i2c_driver = { 380 .driver = { 381 .name = "rmi4_i2c", 382 .pm = &rmi_i2c_pm, 383 .of_match_table = of_match_ptr(rmi_i2c_of_match), 384 }, 385 .id_table = rmi_id, 386 .probe = rmi_i2c_probe, 387 }; 388 389 module_i2c_driver(rmi_i2c_driver); 390 391 MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>"); 392 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>"); 393 MODULE_DESCRIPTION("RMI I2C driver"); 394 MODULE_LICENSE("GPL"); 395