drivers/net/gianfar_ptp.c

   1 /*
   2  * PTP 1588 clock using the eTSEC
   3  *
   4  * Copyright (C) 2010 OMICRON electronics GmbH
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #include <linux/device.h>
  21 #include <linux/hrtimer.h>
  22 #include <linux/init.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/of.h>
  27 #include <linux/of_platform.h>
  28 #include <linux/timex.h>
  29 #include <linux/io.h>
  30
  31 #include <linux/ptp_clock_kernel.h>
  32
  33 #include "gianfar.h"
  34
  35 /*
  36  * gianfar ptp registers
  37  * Generated by regen.tcl on Thu May 13 01:38:57 PM CEST 2010
  38  */
  39 struct gianfar_ptp_registers {
  40         u32 tmr_ctrl;     /* Timer control register */
  41         u32 tmr_tevent;   /* Timestamp event register */
  42         u32 tmr_temask;   /* Timer event mask register */
  43         u32 tmr_pevent;   /* Timestamp event register */
  44         u32 tmr_pemask;   /* Timer event mask register */
  45         u32 tmr_stat;     /* Timestamp status register */
  46         u32 tmr_cnt_h;    /* Timer counter high register */
  47         u32 tmr_cnt_l;    /* Timer counter low register */
  48         u32 tmr_add;      /* Timer drift compensation addend register */
  49         u32 tmr_acc;      /* Timer accumulator register */
  50         u32 tmr_prsc;     /* Timer prescale */
  51         u8  res1[4];
  52         u32 tmroff_h;     /* Timer offset high */
  53         u32 tmroff_l;     /* Timer offset low */
  54         u8  res2[8];
  55         u32 tmr_alarm1_h; /* Timer alarm 1 high register */
  56         u32 tmr_alarm1_l; /* Timer alarm 1 high register */
  57         u32 tmr_alarm2_h; /* Timer alarm 2 high register */
  58         u32 tmr_alarm2_l; /* Timer alarm 2 high register */
  59         u8  res3[48];
  60         u32 tmr_fiper1;   /* Timer fixed period interval */
  61         u32 tmr_fiper2;   /* Timer fixed period interval */
  62         u32 tmr_fiper3;   /* Timer fixed period interval */
  63         u8  res4[20];
  64         u32 tmr_etts1_h;  /* Timestamp of general purpose external trigger */
  65         u32 tmr_etts1_l;  /* Timestamp of general purpose external trigger */
  66         u32 tmr_etts2_h;  /* Timestamp of general purpose external trigger */
  67         u32 tmr_etts2_l;  /* Timestamp of general purpose external trigger */
  68 };
  69
  70 /* Bit definitions for the TMR_CTRL register */
  71 #define ALM1P                 (1<<31) /* Alarm1 output polarity */
  72 #define ALM2P                 (1<<30) /* Alarm2 output polarity */
  73 #define FS                    (1<<28) /* FIPER start indication */
  74 #define PP1L                  (1<<27) /* Fiper1 pulse loopback mode enabled. */
  75 #define PP2L                  (1<<26) /* Fiper2 pulse loopback mode enabled. */
  76 #define TCLK_PERIOD_SHIFT     (16) /* 1588 timer reference clock period. */
  77 #define TCLK_PERIOD_MASK      (0x3ff)
  78 #define RTPE                  (1<<15) /* Record Tx Timestamp to PAL Enable. */
  79 #define FRD                   (1<<14) /* FIPER Realignment Disable */
  80 #define ESFDP                 (1<<11) /* External Tx/Rx SFD Polarity. */
  81 #define ESFDE                 (1<<10) /* External Tx/Rx SFD Enable. */
  82 #define ETEP2                 (1<<9) /* External trigger 2 edge polarity */
  83 #define ETEP1                 (1<<8) /* External trigger 1 edge polarity */
  84 #define COPH                  (1<<7) /* Generated clock output phase. */
  85 #define CIPH                  (1<<6) /* External oscillator input clock phase */
  86 #define TMSR                  (1<<5) /* Timer soft reset. */
  87 #define BYP                   (1<<3) /* Bypass drift compensated clock */
  88 #define TE                    (1<<2) /* 1588 timer enable. */
  89 #define CKSEL_SHIFT           (0)    /* 1588 Timer reference clock source */
  90 #define CKSEL_MASK            (0x3)
  91
  92 /* Bit definitions for the TMR_TEVENT register */
  93 #define ETS2                  (1<<25) /* External trigger 2 timestamp sampled */
  94 #define ETS1                  (1<<24) /* External trigger 1 timestamp sampled */
  95 #define ALM2                  (1<<17) /* Current time = alarm time register 2 */
  96 #define ALM1                  (1<<16) /* Current time = alarm time register 1 */
  97 #define PP1                   (1<<7)  /* periodic pulse generated on FIPER1 */
  98 #define PP2                   (1<<6)  /* periodic pulse generated on FIPER2 */
  99 #define PP3                   (1<<5)  /* periodic pulse generated on FIPER3 */
 100
 101 /* Bit definitions for the TMR_TEMASK register */
 102 #define ETS2EN                (1<<25) /* External trigger 2 timestamp enable */
 103 #define ETS1EN                (1<<24) /* External trigger 1 timestamp enable */
 104 #define ALM2EN                (1<<17) /* Timer ALM2 event enable */
 105 #define ALM1EN                (1<<16) /* Timer ALM1 event enable */
 106 #define PP1EN                 (1<<7) /* Periodic pulse event 1 enable */
 107 #define PP2EN                 (1<<6) /* Periodic pulse event 2 enable */
 108
 109 /* Bit definitions for the TMR_PEVENT register */
 110 #define TXP2                  (1<<9) /* PTP transmitted timestamp im TXTS2 */
 111 #define TXP1                  (1<<8) /* PTP transmitted timestamp in TXTS1 */
 112 #define RXP                   (1<<0) /* PTP frame has been received */
 113
 114 /* Bit definitions for the TMR_PEMASK register */
 115 #define TXP2EN                (1<<9) /* Transmit PTP packet event 2 enable */
 116 #define TXP1EN                (1<<8) /* Transmit PTP packet event 1 enable */
 117 #define RXPEN                 (1<<0) /* Receive PTP packet event enable */
 118
 119 /* Bit definitions for the TMR_STAT register */
 120 #define STAT_VEC_SHIFT        (0) /* Timer general purpose status vector */
 121 #define STAT_VEC_MASK         (0x3f)
 122
 123 /* Bit definitions for the TMR_PRSC register */
 124 #define PRSC_OCK_SHIFT        (0) /* Output clock division/prescale factor. */
 125 #define PRSC_OCK_MASK         (0xffff)
 126
 127
 128 #define DRIVER          "gianfar_ptp"
 129 #define DEFAULT_CKSEL   1
 130 #define N_ALARM         1 /* first alarm is used internally to reset fipers */
 131 #define N_EXT_TS        2
 132 #define REG_SIZE        sizeof(struct gianfar_ptp_registers)
 133
 134 struct etsects {
 135         struct gianfar_ptp_registers *regs;
 136         spinlock_t lock; /* protects regs */
 137         struct ptp_clock *clock;
 138         struct ptp_clock_info caps;
 139         struct resource *rsrc;
 140         int irq;
 141         u64 alarm_interval; /* for periodic alarm */
 142         u64 alarm_value;
 143         u32 tclk_period;  /* nanoseconds */
 144         u32 tmr_prsc;
 145         u32 tmr_add;
 146         u32 cksel;
 147         u32 tmr_fiper1;
 148         u32 tmr_fiper2;
 149 };
 150
 151 /*
 152  * Register access functions
 153  */
 154
 155 /* Caller must hold etsects->lock. */
 156 static u64 tmr_cnt_read(struct etsects *etsects)
 157 {
 158         u64 ns;
 159         u32 lo, hi;
 160
 161         lo = gfar_read(&etsects->regs->tmr_cnt_l);
 162         hi = gfar_read(&etsects->regs->tmr_cnt_h);
 163         ns = ((u64) hi) << 32;
 164         ns |= lo;
 165         return ns;
 166 }
 167
 168 /* Caller must hold etsects->lock. */
 169 static void tmr_cnt_write(struct etsects *etsects, u64 ns)
 170 {
 171         u32 hi = ns >> 32;
 172         u32 lo = ns & 0xffffffff;
 173
 174         gfar_write(&etsects->regs->tmr_cnt_l, lo);
 175         gfar_write(&etsects->regs->tmr_cnt_h, hi);
 176 }
 177
 178 /* Caller must hold etsects->lock. */
 179 static void set_alarm(struct etsects *etsects)
 180 {
 181         u64 ns;
 182         u32 lo, hi;
 183
 184         ns = tmr_cnt_read(etsects) + 1500000000ULL;
 185         ns = div_u64(ns, 1000000000UL) * 1000000000ULL;
 186         ns -= etsects->tclk_period;
 187         hi = ns >> 32;
 188         lo = ns & 0xffffffff;
 189         gfar_write(&etsects->regs->tmr_alarm1_l, lo);
 190         gfar_write(&etsects->regs->tmr_alarm1_h, hi);
 191 }
 192
 193 /* Caller must hold etsects->lock. */
 194 static void set_fipers(struct etsects *etsects)
 195 {
 196         set_alarm(etsects);
 197         gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
 198         gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
 199 }
 200
 201 /*
 202  * Interrupt service routine
 203  */
 204
 205 static irqreturn_t isr(int irq, void *priv)
 206 {
 207         struct etsects *etsects = priv;
 208         struct ptp_clock_event event;
 209         u64 ns;
 210         u32 ack = 0, lo, hi, mask, val;
 211
 212         val = gfar_read(&etsects->regs->tmr_tevent);
 213
 214         if (val & ETS1) {
 215                 ack |= ETS1;
 216                 hi = gfar_read(&etsects->regs->tmr_etts1_h);
 217                 lo = gfar_read(&etsects->regs->tmr_etts1_l);
 218                 event.type = PTP_CLOCK_EXTTS;
 219                 event.index = 0;
 220                 event.timestamp = ((u64) hi) << 32;
 221                 event.timestamp |= lo;
 222                 ptp_clock_event(etsects->clock, &event);
 223         }
 224
 225         if (val & ETS2) {
 226                 ack |= ETS2;
 227                 hi = gfar_read(&etsects->regs->tmr_etts2_h);
 228                 lo = gfar_read(&etsects->regs->tmr_etts2_l);
 229                 event.type = PTP_CLOCK_EXTTS;
 230                 event.index = 1;
 231                 event.timestamp = ((u64) hi) << 32;
 232                 event.timestamp |= lo;
 233                 ptp_clock_event(etsects->clock, &event);
 234         }
 235
 236         if (val & ALM2) {
 237                 ack |= ALM2;
 238                 if (etsects->alarm_value) {
 239                         event.type = PTP_CLOCK_ALARM;
 240                         event.index = 0;
 241                         event.timestamp = etsects->alarm_value;
 242                         ptp_clock_event(etsects->clock, &event);
 243                 }
 244                 if (etsects->alarm_interval) {
 245                         ns = etsects->alarm_value + etsects->alarm_interval;
 246                         hi = ns >> 32;
 247                         lo = ns & 0xffffffff;
 248                         spin_lock(&etsects->lock);
 249                         gfar_write(&etsects->regs->tmr_alarm2_l, lo);
 250                         gfar_write(&etsects->regs->tmr_alarm2_h, hi);
 251                         spin_unlock(&etsects->lock);
 252                         etsects->alarm_value = ns;
 253                 } else {
 254                         gfar_write(&etsects->regs->tmr_tevent, ALM2);
 255                         spin_lock(&etsects->lock);
 256                         mask = gfar_read(&etsects->regs->tmr_temask);
 257                         mask &= ~ALM2EN;
 258                         gfar_write(&etsects->regs->tmr_temask, mask);
 259                         spin_unlock(&etsects->lock);
 260                         etsects->alarm_value = 0;
 261                         etsects->alarm_interval = 0;
 262                 }
 263         }
 264
 265         if (val & PP1) {
 266                 ack |= PP1;
 267                 event.type = PTP_CLOCK_PPS;
 268                 ptp_clock_event(etsects->clock, &event);
 269         }
 270
 271         if (ack) {
 272                 gfar_write(&etsects->regs->tmr_tevent, ack);
 273                 return IRQ_HANDLED;
 274         } else
 275                 return IRQ_NONE;
 276 }
 277
 278 /*
 279  * PTP clock operations
 280  */
 281
 282 static int ptp_gianfar_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 283 {
 284         u64 adj;
 285         u32 diff, tmr_add;
 286         int neg_adj = 0;
 287         struct etsects *etsects = container_of(ptp, struct etsects, caps);
 288
 289         if (ppb < 0) {
 290                 neg_adj = 1;
 291                 ppb = -ppb;
 292         }
 293         tmr_add = etsects->tmr_add;
 294         adj = tmr_add;
 295         adj *= ppb;
 296         diff = div_u64(adj, 1000000000ULL);
 297
 298         tmr_add = neg_adj ? tmr_add - diff : tmr_add + diff;
 299
 300         gfar_write(&etsects->regs->tmr_add, tmr_add);
 301
 302         return 0;
 303 }
 304
 305 static int ptp_gianfar_adjtime(struct ptp_clock_info *ptp, s64 delta)
 306 {
 307         s64 now;
 308         unsigned long flags;
 309         struct etsects *etsects = container_of(ptp, struct etsects, caps);
 310
 311         spin_lock_irqsave(&etsects->lock, flags);
 312
 313         now = tmr_cnt_read(etsects);
 314         now += delta;
 315         tmr_cnt_write(etsects, now);
 316
 317         spin_unlock_irqrestore(&etsects->lock, flags);
 318
 319         set_fipers(etsects);
 320
 321         return 0;
 322 }
 323
 324 static int ptp_gianfar_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
 325 {
 326         u64 ns;
 327         u32 remainder;
 328         unsigned long flags;
 329         struct etsects *etsects = container_of(ptp, struct etsects, caps);
 330
 331         spin_lock_irqsave(&etsects->lock, flags);
 332
 333         ns = tmr_cnt_read(etsects);
 334
 335         spin_unlock_irqrestore(&etsects->lock, flags);
 336
 337         ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
 338         ts->tv_nsec = remainder;
 339         return 0;
 340 }
 341
 342 static int ptp_gianfar_settime(struct ptp_clock_info *ptp,
 343                                const struct timespec *ts)
 344 {
 345         u64 ns;
 346         unsigned long flags;
 347         struct etsects *etsects = container_of(ptp, struct etsects, caps);
 348
 349         ns = ts->tv_sec * 1000000000ULL;
 350         ns += ts->tv_nsec;
 351
 352         spin_lock_irqsave(&etsects->lock, flags);
 353
 354         tmr_cnt_write(etsects, ns);
 355         set_fipers(etsects);
 356
 357         spin_unlock_irqrestore(&etsects->lock, flags);
 358
 359         return 0;
 360 }
 361
 362 static int ptp_gianfar_enable(struct ptp_clock_info *ptp,
 363                               struct ptp_clock_request *rq, int on)
 364 {
 365         struct etsects *etsects = container_of(ptp, struct etsects, caps);
 366         unsigned long flags;
 367         u32 bit, mask;
 368
 369         switch (rq->type) {
 370         case PTP_CLK_REQ_EXTTS:
 371                 switch (rq->extts.index) {
 372                 case 0:
 373                         bit = ETS1EN;
 374                         break;
 375                 case 1:
 376                         bit = ETS2EN;
 377                         break;
 378                 default:
 379                         return -EINVAL;
 380                 }
 381                 spin_lock_irqsave(&etsects->lock, flags);
 382                 mask = gfar_read(&etsects->regs->tmr_temask);
 383                 if (on)
 384                         mask |= bit;
 385                 else
 386                         mask &= ~bit;
 387                 gfar_write(&etsects->regs->tmr_temask, mask);
 388                 spin_unlock_irqrestore(&etsects->lock, flags);
 389                 return 0;
 390
 391         case PTP_CLK_REQ_PPS:
 392                 spin_lock_irqsave(&etsects->lock, flags);
 393                 mask = gfar_read(&etsects->regs->tmr_temask);
 394                 if (on)
 395                         mask |= PP1EN;
 396                 else
 397                         mask &= ~PP1EN;
 398                 gfar_write(&etsects->regs->tmr_temask, mask);
 399                 spin_unlock_irqrestore(&etsects->lock, flags);
 400                 return 0;
 401
 402         default:
 403                 break;
 404         }
 405
 406         return -EOPNOTSUPP;
 407 }
 408
 409 static struct ptp_clock_info ptp_gianfar_caps = {
 410         .owner          = THIS_MODULE,
 411         .name           = "gianfar clock",
 412         .max_adj        = 512000,
 413         .n_alarm        = N_ALARM,
 414         .n_ext_ts       = N_EXT_TS,
 415         .n_per_out      = 0,
 416         .pps            = 1,
 417         .adjfreq        = ptp_gianfar_adjfreq,
 418         .adjtime        = ptp_gianfar_adjtime,
 419         .gettime        = ptp_gianfar_gettime,
 420         .settime        = ptp_gianfar_settime,
 421         .enable         = ptp_gianfar_enable,
 422 };
 423
 424 /* OF device tree */
 425
 426 static int get_of_u32(struct device_node *node, char *str, u32 *val)
 427 {
 428         int plen;
 429         const u32 *prop = of_get_property(node, str, &plen);
 430
 431         if (!prop || plen != sizeof(*prop))
 432                 return -1;
 433         *val = *prop;
 434         return 0;
 435 }
 436
 437 static int gianfar_ptp_probe(struct platform_device *dev)
 438 {
 439         struct device_node *node = dev->dev.of_node;
 440         struct etsects *etsects;
 441         struct timespec now;
 442         int err = -ENOMEM;
 443         u32 tmr_ctrl;
 444         unsigned long flags;
 445
 446         etsects = kzalloc(sizeof(*etsects), GFP_KERNEL);
 447         if (!etsects)
 448                 goto no_memory;
 449
 450         err = -ENODEV;
 451
 452         etsects->caps = ptp_gianfar_caps;
 453         etsects->cksel = DEFAULT_CKSEL;
 454
 455         if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) ||
 456             get_of_u32(node, "fsl,tmr-prsc", &etsects->tmr_prsc) ||
 457             get_of_u32(node, "fsl,tmr-add", &etsects->tmr_add) ||
 458             get_of_u32(node, "fsl,tmr-fiper1", &etsects->tmr_fiper1) ||
 459             get_of_u32(node, "fsl,tmr-fiper2", &etsects->tmr_fiper2) ||
 460             get_of_u32(node, "fsl,max-adj", &etsects->caps.max_adj)) {
 461                 pr_err("device tree node missing required elements\n");
 462                 goto no_node;
 463         }
 464
 465         etsects->irq = platform_get_irq(dev, 0);
 466
 467         if (etsects->irq == NO_IRQ) {
 468                 pr_err("irq not in device tree\n");
 469                 goto no_node;
 470         }
 471         if (request_irq(etsects->irq, isr, 0, DRIVER, etsects)) {
 472                 pr_err("request_irq failed\n");
 473                 goto no_node;
 474         }
 475
 476         etsects->rsrc = platform_get_resource(dev, IORESOURCE_MEM, 0);
 477         if (!etsects->rsrc) {
 478                 pr_err("no resource\n");
 479                 goto no_resource;
 480         }
 481         if (request_resource(&ioport_resource, etsects->rsrc)) {
 482                 pr_err("resource busy\n");
 483                 goto no_resource;
 484         }
 485
 486         spin_lock_init(&etsects->lock);
 487
 488         etsects->regs = ioremap(etsects->rsrc->start,
 489                                 resource_size(etsects->rsrc));
 490         if (!etsects->regs) {
 491                 pr_err("ioremap ptp registers failed\n");
 492                 goto no_ioremap;
 493         }
 494         getnstimeofday(&now);
 495         ptp_gianfar_settime(&etsects->caps, &now);
 496
 497         tmr_ctrl =
 498           (etsects->tclk_period & TCLK_PERIOD_MASK) << TCLK_PERIOD_SHIFT |
 499           (etsects->cksel & CKSEL_MASK) << CKSEL_SHIFT;
 500
 501         spin_lock_irqsave(&etsects->lock, flags);
 502
 503         gfar_write(&etsects->regs->tmr_ctrl,   tmr_ctrl);
 504         gfar_write(&etsects->regs->tmr_add,    etsects->tmr_add);
 505         gfar_write(&etsects->regs->tmr_prsc,   etsects->tmr_prsc);
 506         gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
 507         gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
 508         set_alarm(etsects);
 509         gfar_write(&etsects->regs->tmr_ctrl,   tmr_ctrl|FS|RTPE|TE|FRD);
 510
 511         spin_unlock_irqrestore(&etsects->lock, flags);
 512
 513         etsects->clock = ptp_clock_register(&etsects->caps);
 514         if (IS_ERR(etsects->clock)) {
 515                 err = PTR_ERR(etsects->clock);
 516                 goto no_clock;
 517         }
 518
 519         dev_set_drvdata(&dev->dev, etsects);
 520
 521         return 0;
 522
 523 no_clock:
 524 no_ioremap:
 525         release_resource(etsects->rsrc);
 526 no_resource:
 527         free_irq(etsects->irq, etsects);
 528 no_node:
 529         kfree(etsects);
 530 no_memory:
 531         return err;
 532 }
 533
 534 static int gianfar_ptp_remove(struct platform_device *dev)
 535 {
 536         struct etsects *etsects = dev_get_drvdata(&dev->dev);
 537
 538         gfar_write(&etsects->regs->tmr_temask, 0);
 539         gfar_write(&etsects->regs->tmr_ctrl,   0);
 540
 541         ptp_clock_unregister(etsects->clock);
 542         iounmap(etsects->regs);
 543         release_resource(etsects->rsrc);
 544         free_irq(etsects->irq, etsects);
 545         kfree(etsects);
 546
 547         return 0;
 548 }
 549
 550 static struct of_device_id match_table[] = {
 551         { .compatible = "fsl,etsec-ptp" },
 552         {},
 553 };
 554
 555 static struct platform_driver gianfar_ptp_driver = {
 556         .driver = {
 557                 .name           = "gianfar_ptp",
 558                 .of_match_table = match_table,
 559                 .owner          = THIS_MODULE,
 560         },
 561         .probe       = gianfar_ptp_probe,
 562         .remove      = gianfar_ptp_remove,
 563 };
 564
 565 /* module operations */
 566
 567 static int __init ptp_gianfar_init(void)
 568 {
 569         return platform_driver_register(&gianfar_ptp_driver);
 570 }
 571
 572 module_init(ptp_gianfar_init);
 573
 574 static void __exit ptp_gianfar_exit(void)
 575 {
 576         platform_driver_unregister(&gianfar_ptp_driver);
 577 }
 578
 579 module_exit(ptp_gianfar_exit);
 580
 581 MODULE_AUTHOR("Richard Cochran <richard.cochran@omicron.at>");
 582 MODULE_DESCRIPTION("PTP clock using the eTSEC");
 583 MODULE_LICENSE("GPL");