1 /* 2 * An I2C and SPI driver for the NXP PCF2127/29 RTC 3 * Copyright 2013 Til-Technologies 4 * 5 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr> 6 * 7 * based on the other drivers in this same directory. 8 * 9 * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #include <linux/i2c.h> 17 #include <linux/spi/spi.h> 18 #include <linux/bcd.h> 19 #include <linux/rtc.h> 20 #include <linux/slab.h> 21 #include <linux/module.h> 22 #include <linux/of.h> 23 #include <linux/regmap.h> 24 25 #define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */ 26 #define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */ 27 28 #define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */ 29 #define PCF2127_REG_CTRL3_BLF BIT(2) 30 31 #define PCF2127_REG_SC (0x03) /* datetime */ 32 #define PCF2127_REG_MN (0x04) 33 #define PCF2127_REG_HR (0x05) 34 #define PCF2127_REG_DM (0x06) 35 #define PCF2127_REG_DW (0x07) 36 #define PCF2127_REG_MO (0x08) 37 #define PCF2127_REG_YR (0x09) 38 39 #define PCF2127_OSF BIT(7) /* Oscillator Fail flag */ 40 41 struct pcf2127 { 42 struct rtc_device *rtc; 43 struct regmap *regmap; 44 }; 45 46 /* 47 * In the routines that deal directly with the pcf2127 hardware, we use 48 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. 49 */ 50 static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm) 51 { 52 struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 53 unsigned char buf[10]; 54 int ret; 55 int i; 56 57 for (i = 0; i <= PCF2127_REG_CTRL3; i++) { 58 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1 + i, 59 (unsigned int *)(buf + i)); 60 if (ret) { 61 dev_err(dev, "%s: read error\n", __func__); 62 return ret; 63 } 64 } 65 66 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_SC, 67 (buf + PCF2127_REG_SC), 68 ARRAY_SIZE(buf) - PCF2127_REG_SC); 69 if (ret) { 70 dev_err(dev, "%s: read error\n", __func__); 71 return ret; 72 } 73 74 if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF) 75 dev_info(dev, 76 "low voltage detected, check/replace RTC battery.\n"); 77 78 if (buf[PCF2127_REG_SC] & PCF2127_OSF) { 79 /* 80 * no need clear the flag here, 81 * it will be cleared once the new date is saved 82 */ 83 dev_warn(dev, 84 "oscillator stop detected, date/time is not reliable\n"); 85 return -EINVAL; 86 } 87 88 dev_dbg(dev, 89 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, " 90 "sec=%02x, min=%02x, hr=%02x, " 91 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", 92 __func__, 93 buf[0], buf[1], buf[2], 94 buf[3], buf[4], buf[5], 95 buf[6], buf[7], buf[8], buf[9]); 96 97 98 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F); 99 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F); 100 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */ 101 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F); 102 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07; 103 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ 104 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]); 105 if (tm->tm_year < 70) 106 tm->tm_year += 100; /* assume we are in 1970...2069 */ 107 108 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 109 "mday=%d, mon=%d, year=%d, wday=%d\n", 110 __func__, 111 tm->tm_sec, tm->tm_min, tm->tm_hour, 112 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 113 114 return rtc_valid_tm(tm); 115 } 116 117 static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm) 118 { 119 struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 120 unsigned char buf[7]; 121 int i = 0, err; 122 123 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, " 124 "mday=%d, mon=%d, year=%d, wday=%d\n", 125 __func__, 126 tm->tm_sec, tm->tm_min, tm->tm_hour, 127 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 128 129 /* hours, minutes and seconds */ 130 buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */ 131 buf[i++] = bin2bcd(tm->tm_min); 132 buf[i++] = bin2bcd(tm->tm_hour); 133 buf[i++] = bin2bcd(tm->tm_mday); 134 buf[i++] = tm->tm_wday & 0x07; 135 136 /* month, 1 - 12 */ 137 buf[i++] = bin2bcd(tm->tm_mon + 1); 138 139 /* year */ 140 buf[i++] = bin2bcd(tm->tm_year % 100); 141 142 /* write register's data */ 143 err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i); 144 if (err) { 145 dev_err(dev, 146 "%s: err=%d", __func__, err); 147 return err; 148 } 149 150 return 0; 151 } 152 153 #ifdef CONFIG_RTC_INTF_DEV 154 static int pcf2127_rtc_ioctl(struct device *dev, 155 unsigned int cmd, unsigned long arg) 156 { 157 struct pcf2127 *pcf2127 = dev_get_drvdata(dev); 158 int touser; 159 int ret; 160 161 switch (cmd) { 162 case RTC_VL_READ: 163 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser); 164 if (ret) 165 return ret; 166 167 touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0; 168 169 if (copy_to_user((void __user *)arg, &touser, sizeof(int))) 170 return -EFAULT; 171 return 0; 172 default: 173 return -ENOIOCTLCMD; 174 } 175 } 176 #else 177 #define pcf2127_rtc_ioctl NULL 178 #endif 179 180 static const struct rtc_class_ops pcf2127_rtc_ops = { 181 .ioctl = pcf2127_rtc_ioctl, 182 .read_time = pcf2127_rtc_read_time, 183 .set_time = pcf2127_rtc_set_time, 184 }; 185 186 static int pcf2127_probe(struct device *dev, struct regmap *regmap, 187 const char *name) 188 { 189 struct pcf2127 *pcf2127; 190 191 dev_dbg(dev, "%s\n", __func__); 192 193 pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL); 194 if (!pcf2127) 195 return -ENOMEM; 196 197 pcf2127->regmap = regmap; 198 199 dev_set_drvdata(dev, pcf2127); 200 201 pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops, 202 THIS_MODULE); 203 204 return PTR_ERR_OR_ZERO(pcf2127->rtc); 205 } 206 207 #ifdef CONFIG_OF 208 static const struct of_device_id pcf2127_of_match[] = { 209 { .compatible = "nxp,pcf2127" }, 210 { .compatible = "nxp,pcf2129" }, 211 {} 212 }; 213 MODULE_DEVICE_TABLE(of, pcf2127_of_match); 214 #endif 215 216 #if IS_ENABLED(CONFIG_I2C) 217 218 static int pcf2127_i2c_write(void *context, const void *data, size_t count) 219 { 220 struct device *dev = context; 221 struct i2c_client *client = to_i2c_client(dev); 222 int ret; 223 224 ret = i2c_master_send(client, data, count); 225 if (ret != count) 226 return ret < 0 ? ret : -EIO; 227 228 return 0; 229 } 230 231 static int pcf2127_i2c_gather_write(void *context, 232 const void *reg, size_t reg_size, 233 const void *val, size_t val_size) 234 { 235 struct device *dev = context; 236 struct i2c_client *client = to_i2c_client(dev); 237 int ret; 238 void *buf; 239 240 if (WARN_ON(reg_size != 1)) 241 return -EINVAL; 242 243 buf = kmalloc(val_size + 1, GFP_KERNEL); 244 if (!buf) 245 return -ENOMEM; 246 247 memcpy(buf, reg, 1); 248 memcpy(buf + 1, val, val_size); 249 250 ret = i2c_master_send(client, buf, val_size + 1); 251 if (ret != val_size + 1) 252 return ret < 0 ? ret : -EIO; 253 254 return 0; 255 } 256 257 static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size, 258 void *val, size_t val_size) 259 { 260 struct device *dev = context; 261 struct i2c_client *client = to_i2c_client(dev); 262 int ret; 263 264 if (WARN_ON(reg_size != 1)) 265 return -EINVAL; 266 267 ret = i2c_master_send(client, reg, 1); 268 if (ret != 1) 269 return ret < 0 ? ret : -EIO; 270 271 ret = i2c_master_recv(client, val, val_size); 272 if (ret != val_size) 273 return ret < 0 ? ret : -EIO; 274 275 return 0; 276 } 277 278 /* 279 * The reason we need this custom regmap_bus instead of using regmap_init_i2c() 280 * is that the STOP condition is required between set register address and 281 * read register data when reading from registers. 282 */ 283 static const struct regmap_bus pcf2127_i2c_regmap = { 284 .write = pcf2127_i2c_write, 285 .gather_write = pcf2127_i2c_gather_write, 286 .read = pcf2127_i2c_read, 287 }; 288 289 static struct i2c_driver pcf2127_i2c_driver; 290 291 static int pcf2127_i2c_probe(struct i2c_client *client, 292 const struct i2c_device_id *id) 293 { 294 struct regmap *regmap; 295 static const struct regmap_config config = { 296 .reg_bits = 8, 297 .val_bits = 8, 298 }; 299 300 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 301 return -ENODEV; 302 303 regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap, 304 &client->dev, &config); 305 if (IS_ERR(regmap)) { 306 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n", 307 __func__, PTR_ERR(regmap)); 308 return PTR_ERR(regmap); 309 } 310 311 return pcf2127_probe(&client->dev, regmap, 312 pcf2127_i2c_driver.driver.name); 313 } 314 315 static const struct i2c_device_id pcf2127_i2c_id[] = { 316 { "pcf2127", 0 }, 317 { "pcf2129", 0 }, 318 { } 319 }; 320 MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id); 321 322 static struct i2c_driver pcf2127_i2c_driver = { 323 .driver = { 324 .name = "rtc-pcf2127-i2c", 325 .of_match_table = of_match_ptr(pcf2127_of_match), 326 }, 327 .probe = pcf2127_i2c_probe, 328 .id_table = pcf2127_i2c_id, 329 }; 330 331 static int pcf2127_i2c_register_driver(void) 332 { 333 return i2c_add_driver(&pcf2127_i2c_driver); 334 } 335 336 static void pcf2127_i2c_unregister_driver(void) 337 { 338 i2c_del_driver(&pcf2127_i2c_driver); 339 } 340 341 #else 342 343 static int pcf2127_i2c_register_driver(void) 344 { 345 return 0; 346 } 347 348 static void pcf2127_i2c_unregister_driver(void) 349 { 350 } 351 352 #endif 353 354 #if IS_ENABLED(CONFIG_SPI_MASTER) 355 356 static struct spi_driver pcf2127_spi_driver; 357 358 static int pcf2127_spi_probe(struct spi_device *spi) 359 { 360 static const struct regmap_config config = { 361 .reg_bits = 8, 362 .val_bits = 8, 363 .read_flag_mask = 0xa0, 364 .write_flag_mask = 0x20, 365 }; 366 struct regmap *regmap; 367 368 regmap = devm_regmap_init_spi(spi, &config); 369 if (IS_ERR(regmap)) { 370 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n", 371 __func__, PTR_ERR(regmap)); 372 return PTR_ERR(regmap); 373 } 374 375 return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name); 376 } 377 378 static const struct spi_device_id pcf2127_spi_id[] = { 379 { "pcf2127", 0 }, 380 { "pcf2129", 0 }, 381 { } 382 }; 383 MODULE_DEVICE_TABLE(spi, pcf2127_spi_id); 384 385 static struct spi_driver pcf2127_spi_driver = { 386 .driver = { 387 .name = "rtc-pcf2127-spi", 388 .of_match_table = of_match_ptr(pcf2127_of_match), 389 }, 390 .probe = pcf2127_spi_probe, 391 .id_table = pcf2127_spi_id, 392 }; 393 394 static int pcf2127_spi_register_driver(void) 395 { 396 return spi_register_driver(&pcf2127_spi_driver); 397 } 398 399 static void pcf2127_spi_unregister_driver(void) 400 { 401 spi_unregister_driver(&pcf2127_spi_driver); 402 } 403 404 #else 405 406 static int pcf2127_spi_register_driver(void) 407 { 408 return 0; 409 } 410 411 static void pcf2127_spi_unregister_driver(void) 412 { 413 } 414 415 #endif 416 417 static int __init pcf2127_init(void) 418 { 419 int ret; 420 421 ret = pcf2127_i2c_register_driver(); 422 if (ret) { 423 pr_err("Failed to register pcf2127 i2c driver: %d\n", ret); 424 return ret; 425 } 426 427 ret = pcf2127_spi_register_driver(); 428 if (ret) { 429 pr_err("Failed to register pcf2127 spi driver: %d\n", ret); 430 pcf2127_i2c_unregister_driver(); 431 } 432 433 return ret; 434 } 435 module_init(pcf2127_init) 436 437 static void __exit pcf2127_exit(void) 438 { 439 pcf2127_spi_unregister_driver(); 440 pcf2127_i2c_unregister_driver(); 441 } 442 module_exit(pcf2127_exit) 443 444 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>"); 445 MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver"); 446 MODULE_LICENSE("GPL v2"); 447