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