drivers/rtc/rtc-isl1208.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Intersil ISL1208 rtc class driver
   4  *
   5  * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
   6  */
   7
   8 #include <linux/bcd.h>
   9 #include <linux/clk.h>
  10 #include <linux/i2c.h>
  11 #include <linux/module.h>
  12 #include <linux/of_device.h>
  13 #include <linux/of_irq.h>
  14 #include <linux/rtc.h>
  15
  16 /* Register map */
  17 /* rtc section */
  18 #define ISL1208_REG_SC  0x00
  19 #define ISL1208_REG_MN  0x01
  20 #define ISL1208_REG_HR  0x02
  21 #define ISL1208_REG_HR_MIL     (1<<7)   /* 24h/12h mode */
  22 #define ISL1208_REG_HR_PM      (1<<5)   /* PM/AM bit in 12h mode */
  23 #define ISL1208_REG_DT  0x03
  24 #define ISL1208_REG_MO  0x04
  25 #define ISL1208_REG_YR  0x05
  26 #define ISL1208_REG_DW  0x06
  27 #define ISL1208_RTC_SECTION_LEN 7
  28
  29 /* control/status section */
  30 #define ISL1208_REG_SR  0x07
  31 #define ISL1208_REG_SR_ARST    (1<<7)   /* auto reset */
  32 #define ISL1208_REG_SR_XTOSCB  (1<<6)   /* crystal oscillator */
  33 #define ISL1208_REG_SR_WRTC    (1<<4)   /* write rtc */
  34 #define ISL1208_REG_SR_EVT     (1<<3)   /* event */
  35 #define ISL1208_REG_SR_ALM     (1<<2)   /* alarm */
  36 #define ISL1208_REG_SR_BAT     (1<<1)   /* battery */
  37 #define ISL1208_REG_SR_RTCF    (1<<0)   /* rtc fail */
  38 #define ISL1208_REG_INT 0x08
  39 #define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
  40 #define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
  41 #define ISL1219_REG_EV  0x09
  42 #define ISL1219_REG_EV_EVEN    (1<<4)   /* event detection enable */
  43 #define ISL1219_REG_EV_EVIENB  (1<<7)   /* event in pull-up disable */
  44 #define ISL1208_REG_ATR 0x0a
  45 #define ISL1208_REG_DTR 0x0b
  46
  47 /* alarm section */
  48 #define ISL1208_REG_SCA 0x0c
  49 #define ISL1208_REG_MNA 0x0d
  50 #define ISL1208_REG_HRA 0x0e
  51 #define ISL1208_REG_DTA 0x0f
  52 #define ISL1208_REG_MOA 0x10
  53 #define ISL1208_REG_DWA 0x11
  54 #define ISL1208_ALARM_SECTION_LEN 6
  55
  56 /* user section */
  57 #define ISL1208_REG_USR1 0x12
  58 #define ISL1208_REG_USR2 0x13
  59 #define ISL1208_USR_SECTION_LEN 2
  60
  61 /* event section */
  62 #define ISL1219_REG_SCT 0x14
  63 #define ISL1219_REG_MNT 0x15
  64 #define ISL1219_REG_HRT 0x16
  65 #define ISL1219_REG_DTT 0x17
  66 #define ISL1219_REG_MOT 0x18
  67 #define ISL1219_REG_YRT 0x19
  68 #define ISL1219_EVT_SECTION_LEN 6
  69
  70 static struct i2c_driver isl1208_driver;
  71
  72 /* Chip capabilities table */
  73 struct isl1208_config {
  74         unsigned int    nvmem_length;
  75         unsigned        has_tamper:1;
  76         unsigned        has_timestamp:1;
  77         unsigned        has_inverted_osc_bit:1;
  78 };
  79
  80 static const struct isl1208_config config_isl1208 = {
  81         .nvmem_length = 2,
  82         .has_tamper = false,
  83         .has_timestamp = false
  84 };
  85
  86 static const struct isl1208_config config_isl1209 = {
  87         .nvmem_length = 2,
  88         .has_tamper = true,
  89         .has_timestamp = false
  90 };
  91
  92 static const struct isl1208_config config_isl1218 = {
  93         .nvmem_length = 8,
  94         .has_tamper = false,
  95         .has_timestamp = false
  96 };
  97
  98 static const struct isl1208_config config_isl1219 = {
  99         .nvmem_length = 2,
 100         .has_tamper = true,
 101         .has_timestamp = true
 102 };
 103
 104 static const struct isl1208_config config_raa215300_a0 = {
 105         .nvmem_length = 2,
 106         .has_tamper = false,
 107         .has_timestamp = false,
 108         .has_inverted_osc_bit = true
 109 };
 110
 111 static const struct i2c_device_id isl1208_id[] = {
 112         { "isl1208", .driver_data = (kernel_ulong_t)&config_isl1208 },
 113         { "isl1209", .driver_data = (kernel_ulong_t)&config_isl1209 },
 114         { "isl1218", .driver_data = (kernel_ulong_t)&config_isl1218 },
 115         { "isl1219", .driver_data = (kernel_ulong_t)&config_isl1219 },
 116         { "raa215300_a0", .driver_data = (kernel_ulong_t)&config_raa215300_a0 },
 117         { }
 118 };
 119 MODULE_DEVICE_TABLE(i2c, isl1208_id);
 120
 121 static const __maybe_unused struct of_device_id isl1208_of_match[] = {
 122         { .compatible = "isil,isl1208", .data = &config_isl1208 },
 123         { .compatible = "isil,isl1209", .data = &config_isl1209 },
 124         { .compatible = "isil,isl1218", .data = &config_isl1218 },
 125         { .compatible = "isil,isl1219", .data = &config_isl1219 },
 126         { }
 127 };
 128 MODULE_DEVICE_TABLE(of, isl1208_of_match);
 129
 130 /* Device state */
 131 struct isl1208_state {
 132         struct nvmem_config nvmem_config;
 133         struct rtc_device *rtc;
 134         const struct isl1208_config *config;
 135 };
 136
 137 /* block read */
 138 static int
 139 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
 140                       unsigned len)
 141 {
 142         int ret;
 143
 144         WARN_ON(reg > ISL1219_REG_YRT);
 145         WARN_ON(reg + len > ISL1219_REG_YRT + 1);
 146
 147         ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
 148         return (ret < 0) ? ret : 0;
 149 }
 150
 151 /* block write */
 152 static int
 153 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
 154                      unsigned len)
 155 {
 156         int ret;
 157
 158         WARN_ON(reg > ISL1219_REG_YRT);
 159         WARN_ON(reg + len > ISL1219_REG_YRT + 1);
 160
 161         ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
 162         return (ret < 0) ? ret : 0;
 163 }
 164
 165 /* simple check to see whether we have a isl1208 */
 166 static int
 167 isl1208_i2c_validate_client(struct i2c_client *client)
 168 {
 169         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 170         u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
 171                 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
 172         };
 173         int i;
 174         int ret;
 175
 176         ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 177         if (ret < 0)
 178                 return ret;
 179
 180         for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
 181                 if (regs[i] & zero_mask[i])     /* check if bits are cleared */
 182                         return -ENODEV;
 183         }
 184
 185         return 0;
 186 }
 187
 188 static int isl1208_set_xtoscb(struct i2c_client *client, int sr, int xtosb_val)
 189 {
 190         /* Do nothing if bit is already set to desired value */
 191         if ((sr & ISL1208_REG_SR_XTOSCB) == xtosb_val)
 192                 return 0;
 193
 194         if (xtosb_val)
 195                 sr |= ISL1208_REG_SR_XTOSCB;
 196         else
 197                 sr &= ~ISL1208_REG_SR_XTOSCB;
 198
 199         return i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
 200 }
 201
 202 static int
 203 isl1208_i2c_get_sr(struct i2c_client *client)
 204 {
 205         return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
 206 }
 207
 208 static int
 209 isl1208_i2c_get_atr(struct i2c_client *client)
 210 {
 211         int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
 212         if (atr < 0)
 213                 return atr;
 214
 215         /* The 6bit value in the ATR register controls the load
 216          * capacitance C_load * in steps of 0.25pF
 217          *
 218          * bit (1<<5) of the ATR register is inverted
 219          *
 220          * C_load(ATR=0x20) =  4.50pF
 221          * C_load(ATR=0x00) = 12.50pF
 222          * C_load(ATR=0x1f) = 20.25pF
 223          *
 224          */
 225
 226         atr &= 0x3f;            /* mask out lsb */
 227         atr ^= 1 << 5;          /* invert 6th bit */
 228         atr += 2 * 9;           /* add offset of 4.5pF; unit[atr] = 0.25pF */
 229
 230         return atr;
 231 }
 232
 233 /* returns adjustment value + 100 */
 234 static int
 235 isl1208_i2c_get_dtr(struct i2c_client *client)
 236 {
 237         int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
 238         if (dtr < 0)
 239                 return -EIO;
 240
 241         /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
 242         dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
 243
 244         return dtr + 100;
 245 }
 246
 247 static int
 248 isl1208_i2c_get_usr(struct i2c_client *client)
 249 {
 250         u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
 251         int ret;
 252
 253         ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
 254                                     ISL1208_USR_SECTION_LEN);
 255         if (ret < 0)
 256                 return ret;
 257
 258         return (buf[1] << 8) | buf[0];
 259 }
 260
 261 static int
 262 isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
 263 {
 264         u8 buf[ISL1208_USR_SECTION_LEN];
 265
 266         buf[0] = usr & 0xff;
 267         buf[1] = (usr >> 8) & 0xff;
 268
 269         return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
 270                                     ISL1208_USR_SECTION_LEN);
 271 }
 272
 273 static int
 274 isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
 275 {
 276         int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
 277
 278         if (icr < 0) {
 279                 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
 280                 return icr;
 281         }
 282
 283         if (enable)
 284                 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
 285         else
 286                 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
 287
 288         icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
 289         if (icr < 0) {
 290                 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
 291                 return icr;
 292         }
 293
 294         return 0;
 295 }
 296
 297 static int
 298 isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
 299 {
 300         struct i2c_client *const client = to_i2c_client(dev);
 301         int sr, dtr, atr, usr;
 302
 303         sr = isl1208_i2c_get_sr(client);
 304         if (sr < 0) {
 305                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 306                 return sr;
 307         }
 308
 309         seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
 310                    (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
 311                    (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
 312                    (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
 313                    (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
 314                    (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
 315                    (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
 316
 317         seq_printf(seq, "batt_status\t: %s\n",
 318                    (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
 319
 320         dtr = isl1208_i2c_get_dtr(client);
 321         if (dtr >= 0)
 322                 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100);
 323
 324         atr = isl1208_i2c_get_atr(client);
 325         if (atr >= 0)
 326                 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
 327                            atr >> 2, (atr & 0x3) * 25);
 328
 329         usr = isl1208_i2c_get_usr(client);
 330         if (usr >= 0)
 331                 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
 332
 333         return 0;
 334 }
 335
 336 static int
 337 isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
 338 {
 339         int sr;
 340         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 341
 342         sr = isl1208_i2c_get_sr(client);
 343         if (sr < 0) {
 344                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 345                 return -EIO;
 346         }
 347
 348         sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 349         if (sr < 0) {
 350                 dev_err(&client->dev, "%s: reading RTC section failed\n",
 351                         __func__);
 352                 return sr;
 353         }
 354
 355         tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
 356         tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
 357
 358         /* HR field has a more complex interpretation */
 359         {
 360                 const u8 _hr = regs[ISL1208_REG_HR];
 361                 if (_hr & ISL1208_REG_HR_MIL)   /* 24h format */
 362                         tm->tm_hour = bcd2bin(_hr & 0x3f);
 363                 else {
 364                         /* 12h format */
 365                         tm->tm_hour = bcd2bin(_hr & 0x1f);
 366                         if (_hr & ISL1208_REG_HR_PM)    /* PM flag set */
 367                                 tm->tm_hour += 12;
 368                 }
 369         }
 370
 371         tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
 372         tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
 373         tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
 374         tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
 375
 376         return 0;
 377 }
 378
 379 static int
 380 isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 381 {
 382         struct rtc_time *const tm = &alarm->time;
 383         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
 384         int icr, yr, sr = isl1208_i2c_get_sr(client);
 385
 386         if (sr < 0) {
 387                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 388                 return sr;
 389         }
 390
 391         sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
 392                                    ISL1208_ALARM_SECTION_LEN);
 393         if (sr < 0) {
 394                 dev_err(&client->dev, "%s: reading alarm section failed\n",
 395                         __func__);
 396                 return sr;
 397         }
 398
 399         /* MSB of each alarm register is an enable bit */
 400         tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
 401         tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
 402         tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
 403         tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
 404         tm->tm_mon =
 405                 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
 406         tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
 407
 408         /* The alarm doesn't store the year so get it from the rtc section */
 409         yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
 410         if (yr < 0) {
 411                 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
 412                 return yr;
 413         }
 414         tm->tm_year = bcd2bin(yr) + 100;
 415
 416         icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
 417         if (icr < 0) {
 418                 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
 419                 return icr;
 420         }
 421         alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
 422
 423         return 0;
 424 }
 425
 426 static int
 427 isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 428 {
 429         struct rtc_time *alarm_tm = &alarm->time;
 430         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
 431         const int offs = ISL1208_REG_SCA;
 432         struct rtc_time rtc_tm;
 433         int err, enable;
 434
 435         err = isl1208_i2c_read_time(client, &rtc_tm);
 436         if (err)
 437                 return err;
 438
 439         /* If the alarm time is before the current time disable the alarm */
 440         if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
 441                 enable = 0x00;
 442         else
 443                 enable = 0x80;
 444
 445         /* Program the alarm and enable it for each setting */
 446         regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
 447         regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
 448         regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
 449                 ISL1208_REG_HR_MIL | enable;
 450
 451         regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
 452         regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
 453         regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
 454
 455         /* write ALARM registers */
 456         err = isl1208_i2c_set_regs(client, offs, regs,
 457                                   ISL1208_ALARM_SECTION_LEN);
 458         if (err < 0) {
 459                 dev_err(&client->dev, "%s: writing ALARM section failed\n",
 460                         __func__);
 461                 return err;
 462         }
 463
 464         err = isl1208_rtc_toggle_alarm(client, enable);
 465         if (err)
 466                 return err;
 467
 468         return 0;
 469 }
 470
 471 static int
 472 isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
 473 {
 474         return isl1208_i2c_read_time(to_i2c_client(dev), tm);
 475 }
 476
 477 static int
 478 isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
 479 {
 480         int sr;
 481         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 482
 483         /* The clock has an 8 bit wide bcd-coded register (they never learn)
 484          * for the year. tm_year is an offset from 1900 and we are interested
 485          * in the 2000-2099 range, so any value less than 100 is invalid.
 486          */
 487         if (tm->tm_year < 100)
 488                 return -EINVAL;
 489
 490         regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
 491         regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
 492         regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
 493
 494         regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
 495         regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
 496         regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
 497
 498         regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
 499
 500         sr = isl1208_i2c_get_sr(client);
 501         if (sr < 0) {
 502                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 503                 return sr;
 504         }
 505
 506         /* set WRTC */
 507         sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
 508                                        sr | ISL1208_REG_SR_WRTC);
 509         if (sr < 0) {
 510                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
 511                 return sr;
 512         }
 513
 514         /* write RTC registers */
 515         sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 516         if (sr < 0) {
 517                 dev_err(&client->dev, "%s: writing RTC section failed\n",
 518                         __func__);
 519                 return sr;
 520         }
 521
 522         /* clear WRTC again */
 523         sr = isl1208_i2c_get_sr(client);
 524         if (sr < 0) {
 525                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 526                 return sr;
 527         }
 528         sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
 529                                        sr & ~ISL1208_REG_SR_WRTC);
 530         if (sr < 0) {
 531                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
 532                 return sr;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int
 539 isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
 540 {
 541         return isl1208_i2c_set_time(to_i2c_client(dev), tm);
 542 }
 543
 544 static int
 545 isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 546 {
 547         return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
 548 }
 549
 550 static int
 551 isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 552 {
 553         return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
 554 }
 555
 556 static ssize_t timestamp0_store(struct device *dev,
 557                                 struct device_attribute *attr,
 558                                 const char *buf, size_t count)
 559 {
 560         struct i2c_client *client = to_i2c_client(dev->parent);
 561         int sr;
 562
 563         sr = isl1208_i2c_get_sr(client);
 564         if (sr < 0) {
 565                 dev_err(dev, "%s: reading SR failed\n", __func__);
 566                 return sr;
 567         }
 568
 569         sr &= ~ISL1208_REG_SR_EVT;
 570
 571         sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
 572         if (sr < 0)
 573                 dev_err(dev, "%s: writing SR failed\n",
 574                         __func__);
 575
 576         return count;
 577 };
 578
 579 static ssize_t timestamp0_show(struct device *dev,
 580                                struct device_attribute *attr, char *buf)
 581 {
 582         struct i2c_client *client = to_i2c_client(dev->parent);
 583         u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
 584         struct rtc_time tm;
 585         int sr;
 586
 587         sr = isl1208_i2c_get_sr(client);
 588         if (sr < 0) {
 589                 dev_err(dev, "%s: reading SR failed\n", __func__);
 590                 return sr;
 591         }
 592
 593         if (!(sr & ISL1208_REG_SR_EVT))
 594                 return 0;
 595
 596         sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
 597                                    ISL1219_EVT_SECTION_LEN);
 598         if (sr < 0) {
 599                 dev_err(dev, "%s: reading event section failed\n",
 600                         __func__);
 601                 return 0;
 602         }
 603
 604         /* MSB of each alarm register is an enable bit */
 605         tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
 606         tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
 607         tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
 608         tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
 609         tm.tm_mon =
 610                 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
 611         tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
 612
 613         sr = rtc_valid_tm(&tm);
 614         if (sr)
 615                 return sr;
 616
 617         return sprintf(buf, "%llu\n",
 618                                 (unsigned long long)rtc_tm_to_time64(&tm));
 619 };
 620
 621 static DEVICE_ATTR_RW(timestamp0);
 622
 623 static irqreturn_t
 624 isl1208_rtc_interrupt(int irq, void *data)
 625 {
 626         unsigned long timeout = jiffies + msecs_to_jiffies(1000);
 627         struct i2c_client *client = data;
 628         struct isl1208_state *isl1208 = i2c_get_clientdata(client);
 629         int handled = 0, sr, err;
 630
 631         /*
 632          * I2C reads get NAK'ed if we read straight away after an interrupt?
 633          * Using a mdelay/msleep didn't seem to help either, so we work around
 634          * this by continually trying to read the register for a short time.
 635          */
 636         while (1) {
 637                 sr = isl1208_i2c_get_sr(client);
 638                 if (sr >= 0)
 639                         break;
 640
 641                 if (time_after(jiffies, timeout)) {
 642                         dev_err(&client->dev, "%s: reading SR failed\n",
 643                                 __func__);
 644                         return sr;
 645                 }
 646         }
 647
 648         if (sr & ISL1208_REG_SR_ALM) {
 649                 dev_dbg(&client->dev, "alarm!\n");
 650
 651                 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
 652
 653                 /* Clear the alarm */
 654                 sr &= ~ISL1208_REG_SR_ALM;
 655                 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
 656                 if (sr < 0)
 657                         dev_err(&client->dev, "%s: writing SR failed\n",
 658                                 __func__);
 659                 else
 660                         handled = 1;
 661
 662                 /* Disable the alarm */
 663                 err = isl1208_rtc_toggle_alarm(client, 0);
 664                 if (err)
 665                         return err;
 666         }
 667
 668         if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
 669                 dev_warn(&client->dev, "event detected");
 670                 handled = 1;
 671                 if (isl1208->config->has_timestamp)
 672                         sysfs_notify(&isl1208->rtc->dev.kobj, NULL,
 673                                      dev_attr_timestamp0.attr.name);
 674         }
 675
 676         return handled ? IRQ_HANDLED : IRQ_NONE;
 677 }
 678
 679 static const struct rtc_class_ops isl1208_rtc_ops = {
 680         .proc = isl1208_rtc_proc,
 681         .read_time = isl1208_rtc_read_time,
 682         .set_time = isl1208_rtc_set_time,
 683         .read_alarm = isl1208_rtc_read_alarm,
 684         .set_alarm = isl1208_rtc_set_alarm,
 685 };
 686
 687 /* sysfs interface */
 688
 689 static ssize_t
 690 isl1208_sysfs_show_atrim(struct device *dev,
 691                          struct device_attribute *attr, char *buf)
 692 {
 693         int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent));
 694         if (atr < 0)
 695                 return atr;
 696
 697         return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
 698 }
 699
 700 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
 701
 702 static ssize_t
 703 isl1208_sysfs_show_dtrim(struct device *dev,
 704                          struct device_attribute *attr, char *buf)
 705 {
 706         int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent));
 707         if (dtr < 0)
 708                 return dtr;
 709
 710         return sprintf(buf, "%d ppm\n", dtr - 100);
 711 }
 712
 713 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
 714
 715 static ssize_t
 716 isl1208_sysfs_show_usr(struct device *dev,
 717                        struct device_attribute *attr, char *buf)
 718 {
 719         int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent));
 720         if (usr < 0)
 721                 return usr;
 722
 723         return sprintf(buf, "0x%.4x\n", usr);
 724 }
 725
 726 static ssize_t
 727 isl1208_sysfs_store_usr(struct device *dev,
 728                         struct device_attribute *attr,
 729                         const char *buf, size_t count)
 730 {
 731         int usr = -1;
 732
 733         if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
 734                 if (sscanf(buf, "%x", &usr) != 1)
 735                         return -EINVAL;
 736         } else {
 737                 if (sscanf(buf, "%d", &usr) != 1)
 738                         return -EINVAL;
 739         }
 740
 741         if (usr < 0 || usr > 0xffff)
 742                 return -EINVAL;
 743
 744         if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr))
 745                 return -EIO;
 746
 747         return count;
 748 }
 749
 750 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
 751                    isl1208_sysfs_store_usr);
 752
 753 static struct attribute *isl1208_rtc_attrs[] = {
 754         &dev_attr_atrim.attr,
 755         &dev_attr_dtrim.attr,
 756         &dev_attr_usr.attr,
 757         NULL
 758 };
 759
 760 static const struct attribute_group isl1208_rtc_sysfs_files = {
 761         .attrs  = isl1208_rtc_attrs,
 762 };
 763
 764 static struct attribute *isl1219_rtc_attrs[] = {
 765         &dev_attr_timestamp0.attr,
 766         NULL
 767 };
 768
 769 static const struct attribute_group isl1219_rtc_sysfs_files = {
 770         .attrs  = isl1219_rtc_attrs,
 771 };
 772
 773 static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
 774                               size_t count)
 775 {
 776         struct isl1208_state *isl1208 = priv;
 777         struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
 778         int ret;
 779
 780         /* nvmem sanitizes offset/count for us, but count==0 is possible */
 781         if (!count)
 782                 return count;
 783         ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf,
 784                                     count);
 785         return ret == 0 ? count : ret;
 786 }
 787
 788 static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
 789                                size_t count)
 790 {
 791         struct isl1208_state *isl1208 = priv;
 792         struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
 793         int ret;
 794
 795         /* nvmem sanitizes off/count for us, but count==0 is possible */
 796         if (!count)
 797                 return count;
 798         ret = isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf,
 799                                    count);
 800
 801         return ret == 0 ? count : ret;
 802 }
 803
 804 static const struct nvmem_config isl1208_nvmem_config = {
 805         .name = "isl1208_nvram",
 806         .word_size = 1,
 807         .stride = 1,
 808         /* .size from chip specific config */
 809         .reg_read = isl1208_nvmem_read,
 810         .reg_write = isl1208_nvmem_write,
 811 };
 812
 813 static int isl1208_setup_irq(struct i2c_client *client, int irq)
 814 {
 815         int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
 816                                         isl1208_rtc_interrupt,
 817                                         IRQF_SHARED | IRQF_ONESHOT,
 818                                         isl1208_driver.driver.name,
 819                                         client);
 820         if (!rc) {
 821                 device_init_wakeup(&client->dev, 1);
 822                 enable_irq_wake(irq);
 823         } else {
 824                 dev_err(&client->dev,
 825                         "Unable to request irq %d, no alarm support\n",
 826                         irq);
 827         }
 828         return rc;
 829 }
 830
 831 static int
 832 isl1208_clk_present(struct i2c_client *client, const char *name)
 833 {
 834         struct clk *clk;
 835
 836         clk = devm_clk_get_optional(&client->dev, name);
 837         if (IS_ERR(clk))
 838                 return PTR_ERR(clk);
 839
 840         return !!clk;
 841 }
 842
 843 static int
 844 isl1208_probe(struct i2c_client *client)
 845 {
 846         struct isl1208_state *isl1208;
 847         int evdet_irq = -1;
 848         int xtosb_val = 0;
 849         int rc = 0;
 850         int sr;
 851
 852         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 853                 return -ENODEV;
 854
 855         if (isl1208_i2c_validate_client(client) < 0)
 856                 return -ENODEV;
 857
 858         /* Allocate driver state, point i2c client data to it */
 859         isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL);
 860         if (!isl1208)
 861                 return -ENOMEM;
 862         i2c_set_clientdata(client, isl1208);
 863
 864         /* Determine which chip we have */
 865         if (client->dev.of_node) {
 866                 isl1208->config = of_device_get_match_data(&client->dev);
 867                 if (!isl1208->config)
 868                         return -ENODEV;
 869         } else {
 870                 const struct i2c_device_id *id = i2c_match_id(isl1208_id, client);
 871
 872                 if (!id)
 873                         return -ENODEV;
 874                 isl1208->config = (struct isl1208_config *)id->driver_data;
 875         }
 876
 877         rc = isl1208_clk_present(client, "xin");
 878         if (rc < 0)
 879                 return rc;
 880
 881         if (!rc) {
 882                 rc = isl1208_clk_present(client, "clkin");
 883                 if (rc < 0)
 884                         return rc;
 885
 886                 if (rc)
 887                         xtosb_val = 1;
 888         }
 889
 890         isl1208->rtc = devm_rtc_allocate_device(&client->dev);
 891         if (IS_ERR(isl1208->rtc))
 892                 return PTR_ERR(isl1208->rtc);
 893
 894         isl1208->rtc->ops = &isl1208_rtc_ops;
 895
 896         /* Setup nvmem configuration in driver state struct */
 897         isl1208->nvmem_config = isl1208_nvmem_config;
 898         isl1208->nvmem_config.size = isl1208->config->nvmem_length;
 899         isl1208->nvmem_config.priv = isl1208;
 900
 901         sr = isl1208_i2c_get_sr(client);
 902         if (sr < 0) {
 903                 dev_err(&client->dev, "reading status failed\n");
 904                 return sr;
 905         }
 906
 907         if (isl1208->config->has_inverted_osc_bit)
 908                 xtosb_val = !xtosb_val;
 909
 910         rc = isl1208_set_xtoscb(client, sr, xtosb_val);
 911         if (rc)
 912                 return rc;
 913
 914         if (sr & ISL1208_REG_SR_RTCF)
 915                 dev_warn(&client->dev, "rtc power failure detected, "
 916                          "please set clock.\n");
 917
 918         if (isl1208->config->has_tamper) {
 919                 struct device_node *np = client->dev.of_node;
 920                 u32 evienb;
 921
 922                 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
 923                 if (rc < 0) {
 924                         dev_err(&client->dev, "failed to read EV reg\n");
 925                         return rc;
 926                 }
 927                 rc |= ISL1219_REG_EV_EVEN;
 928                 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
 929                         if (evienb)
 930                                 rc |= ISL1219_REG_EV_EVIENB;
 931                         else
 932                                 rc &= ~ISL1219_REG_EV_EVIENB;
 933                 }
 934                 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
 935                 if (rc < 0) {
 936                         dev_err(&client->dev, "could not enable tamper detection\n");
 937                         return rc;
 938                 }
 939                 evdet_irq = of_irq_get_byname(np, "evdet");
 940         }
 941         if (isl1208->config->has_timestamp) {
 942                 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files);
 943                 if (rc)
 944                         return rc;
 945         }
 946
 947         rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files);
 948         if (rc)
 949                 return rc;
 950
 951         if (client->irq > 0) {
 952                 rc = isl1208_setup_irq(client, client->irq);
 953                 if (rc)
 954                         return rc;
 955
 956         } else {
 957                 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, isl1208->rtc->features);
 958         }
 959
 960         if (evdet_irq > 0 && evdet_irq != client->irq)
 961                 rc = isl1208_setup_irq(client, evdet_irq);
 962         if (rc)
 963                 return rc;
 964
 965         rc = devm_rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config);
 966         if (rc)
 967                 return rc;
 968
 969         return devm_rtc_register_device(isl1208->rtc);
 970 }
 971
 972 static struct i2c_driver isl1208_driver = {
 973         .driver = {
 974                 .name = "rtc-isl1208",
 975                 .of_match_table = of_match_ptr(isl1208_of_match),
 976         },
 977         .probe = isl1208_probe,
 978         .id_table = isl1208_id,
 979 };
 980
 981 module_i2c_driver(isl1208_driver);
 982
 983 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
 984 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
 985 MODULE_LICENSE("GPL");