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 { 203 struct rmi_device_platform_data *pdata; 204 struct rmi_device_platform_data *client_pdata = 205 dev_get_platdata(&client->dev); 206 struct rmi_i2c_xport *rmi_i2c; 207 int error; 208 209 rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport), 210 GFP_KERNEL); 211 if (!rmi_i2c) 212 return -ENOMEM; 213 214 pdata = &rmi_i2c->xport.pdata; 215 216 if (!client->dev.of_node && client_pdata) 217 *pdata = *client_pdata; 218 219 pdata->irq = client->irq; 220 221 rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n", 222 dev_name(&client->dev)); 223 224 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 225 dev_err(&client->dev, 226 "adapter does not support required functionality\n"); 227 return -ENODEV; 228 } 229 230 rmi_i2c->supplies[0].supply = "vdd"; 231 rmi_i2c->supplies[1].supply = "vio"; 232 error = devm_regulator_bulk_get(&client->dev, 233 ARRAY_SIZE(rmi_i2c->supplies), 234 rmi_i2c->supplies); 235 if (error < 0) 236 return error; 237 238 error = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), 239 rmi_i2c->supplies); 240 if (error < 0) 241 return error; 242 243 error = devm_add_action_or_reset(&client->dev, 244 rmi_i2c_regulator_bulk_disable, 245 rmi_i2c); 246 if (error) 247 return error; 248 249 of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms", 250 &rmi_i2c->startup_delay); 251 252 msleep(rmi_i2c->startup_delay); 253 254 rmi_i2c->client = client; 255 mutex_init(&rmi_i2c->page_mutex); 256 257 rmi_i2c->xport.dev = &client->dev; 258 rmi_i2c->xport.proto_name = "i2c"; 259 rmi_i2c->xport.ops = &rmi_i2c_ops; 260 261 i2c_set_clientdata(client, rmi_i2c); 262 263 /* 264 * Setting the page to zero will (a) make sure the PSR is in a 265 * known state, and (b) make sure we can talk to the device. 266 */ 267 error = rmi_set_page(rmi_i2c, 0); 268 if (error) { 269 dev_err(&client->dev, "Failed to set page select to 0\n"); 270 return error; 271 } 272 273 dev_info(&client->dev, "registering I2C-connected sensor\n"); 274 275 error = rmi_register_transport_device(&rmi_i2c->xport); 276 if (error) { 277 dev_err(&client->dev, "failed to register sensor: %d\n", error); 278 return error; 279 } 280 281 error = devm_add_action_or_reset(&client->dev, 282 rmi_i2c_unregister_transport, 283 rmi_i2c); 284 if (error) 285 return error; 286 287 return 0; 288 } 289 290 static int rmi_i2c_suspend(struct device *dev) 291 { 292 struct i2c_client *client = to_i2c_client(dev); 293 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 294 int ret; 295 296 ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true); 297 if (ret) 298 dev_warn(dev, "Failed to resume device: %d\n", ret); 299 300 regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies), 301 rmi_i2c->supplies); 302 303 return ret; 304 } 305 306 static int rmi_i2c_resume(struct device *dev) 307 { 308 struct i2c_client *client = to_i2c_client(dev); 309 struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client); 310 int ret; 311 312 ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies), 313 rmi_i2c->supplies); 314 if (ret) 315 return ret; 316 317 msleep(rmi_i2c->startup_delay); 318 319 ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true); 320 if (ret) 321 dev_warn(dev, "Failed to resume device: %d\n", ret); 322 323 return ret; 324 } 325 326 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 } 361 362 static const struct dev_pm_ops rmi_i2c_pm = { 363 SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume) 364 RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume, NULL) 365 }; 366 367 static const struct i2c_device_id rmi_id[] = { 368 { "rmi4_i2c", 0 }, 369 { } 370 }; 371 MODULE_DEVICE_TABLE(i2c, rmi_id); 372 373 static struct i2c_driver rmi_i2c_driver = { 374 .driver = { 375 .name = "rmi4_i2c", 376 .pm = pm_ptr(&rmi_i2c_pm), 377 .of_match_table = of_match_ptr(rmi_i2c_of_match), 378 }, 379 .id_table = rmi_id, 380 .probe_new = rmi_i2c_probe, 381 }; 382 383 module_i2c_driver(rmi_i2c_driver); 384 385 MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>"); 386 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>"); 387 MODULE_DESCRIPTION("RMI I2C driver"); 388 MODULE_LICENSE("GPL"); 389