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