drivers/net/ethernet/renesas/ravb_ptp.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* PTP 1588 clock using the Renesas Ethernet AVB
   3  *
   4  * Copyright (C) 2013-2015 Renesas Electronics Corporation
   5  * Copyright (C) 2015 Renesas Solutions Corp.
   6  * Copyright (C) 2015-2016 Cogent Embedded, Inc. <source@cogentembedded.com>
   7  */
   8
   9 #include "ravb.h"
  10
  11 static int ravb_ptp_tcr_request(struct ravb_private *priv, u32 request)
  12 {
  13         struct net_device *ndev = priv->ndev;
  14         int error;
  15
  16         error = ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
  17         if (error)
  18                 return error;
  19
  20         ravb_modify(ndev, GCCR, request, request);
  21         return ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
  22 }
  23
  24 /* Caller must hold the lock */
  25 static int ravb_ptp_time_read(struct ravb_private *priv, struct timespec64 *ts)
  26 {
  27         struct net_device *ndev = priv->ndev;
  28         int error;
  29
  30         error = ravb_ptp_tcr_request(priv, GCCR_TCR_CAPTURE);
  31         if (error)
  32                 return error;
  33
  34         ts->tv_nsec = ravb_read(ndev, GCT0);
  35         ts->tv_sec  = ravb_read(ndev, GCT1) |
  36                 ((s64)ravb_read(ndev, GCT2) << 32);
  37
  38         return 0;
  39 }
  40
  41 /* Caller must hold the lock */
  42 static int ravb_ptp_time_write(struct ravb_private *priv,
  43                                 const struct timespec64 *ts)
  44 {
  45         struct net_device *ndev = priv->ndev;
  46         int error;
  47         u32 gccr;
  48
  49         error = ravb_ptp_tcr_request(priv, GCCR_TCR_RESET);
  50         if (error)
  51                 return error;
  52
  53         gccr = ravb_read(ndev, GCCR);
  54         if (gccr & GCCR_LTO)
  55                 return -EBUSY;
  56         ravb_write(ndev, ts->tv_nsec, GTO0);
  57         ravb_write(ndev, ts->tv_sec,  GTO1);
  58         ravb_write(ndev, (ts->tv_sec >> 32) & 0xffff, GTO2);
  59         ravb_write(ndev, gccr | GCCR_LTO, GCCR);
  60
  61         return 0;
  62 }
  63
  64 /* Caller must hold the lock */
  65 static int ravb_ptp_update_compare(struct ravb_private *priv, u32 ns)
  66 {
  67         struct net_device *ndev = priv->ndev;
  68         /* When the comparison value (GPTC.PTCV) is in range of
  69          * [x-1 to x+1] (x is the configured increment value in
  70          * GTI.TIV), it may happen that a comparison match is
  71          * not detected when the timer wraps around.
  72          */
  73         u32 gti_ns_plus_1 = (priv->ptp.current_addend >> 20) + 1;
  74         u32 gccr;
  75
  76         if (ns < gti_ns_plus_1)
  77                 ns = gti_ns_plus_1;
  78         else if (ns > 0 - gti_ns_plus_1)
  79                 ns = 0 - gti_ns_plus_1;
  80
  81         gccr = ravb_read(ndev, GCCR);
  82         if (gccr & GCCR_LPTC)
  83                 return -EBUSY;
  84         ravb_write(ndev, ns, GPTC);
  85         ravb_write(ndev, gccr | GCCR_LPTC, GCCR);
  86
  87         return 0;
  88 }
  89
  90 /* PTP clock operations */
  91 static int ravb_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
  92 {
  93         struct ravb_private *priv = container_of(ptp, struct ravb_private,
  94                                                  ptp.info);
  95         struct net_device *ndev = priv->ndev;
  96         unsigned long flags;
  97         u32 diff, addend;
  98         bool neg_adj = false;
  99         u32 gccr;
 100
 101         if (ppb < 0) {
 102                 neg_adj = true;
 103                 ppb = -ppb;
 104         }
 105         addend = priv->ptp.default_addend;
 106         diff = div_u64((u64)addend * ppb, NSEC_PER_SEC);
 107
 108         addend = neg_adj ? addend - diff : addend + diff;
 109
 110         spin_lock_irqsave(&priv->lock, flags);
 111
 112         priv->ptp.current_addend = addend;
 113
 114         gccr = ravb_read(ndev, GCCR);
 115         if (gccr & GCCR_LTI) {
 116                 spin_unlock_irqrestore(&priv->lock, flags);
 117                 return -EBUSY;
 118         }
 119         ravb_write(ndev, addend & GTI_TIV, GTI);
 120         ravb_write(ndev, gccr | GCCR_LTI, GCCR);
 121
 122         spin_unlock_irqrestore(&priv->lock, flags);
 123
 124         return 0;
 125 }
 126
 127 static int ravb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 128 {
 129         struct ravb_private *priv = container_of(ptp, struct ravb_private,
 130                                                  ptp.info);
 131         struct timespec64 ts;
 132         unsigned long flags;
 133         int error;
 134
 135         spin_lock_irqsave(&priv->lock, flags);
 136         error = ravb_ptp_time_read(priv, &ts);
 137         if (!error) {
 138                 u64 now = ktime_to_ns(timespec64_to_ktime(ts));
 139
 140                 ts = ns_to_timespec64(now + delta);
 141                 error = ravb_ptp_time_write(priv, &ts);
 142         }
 143         spin_unlock_irqrestore(&priv->lock, flags);
 144
 145         return error;
 146 }
 147
 148 static int ravb_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts)
 149 {
 150         struct ravb_private *priv = container_of(ptp, struct ravb_private,
 151                                                  ptp.info);
 152         unsigned long flags;
 153         int error;
 154
 155         spin_lock_irqsave(&priv->lock, flags);
 156         error = ravb_ptp_time_read(priv, ts);
 157         spin_unlock_irqrestore(&priv->lock, flags);
 158
 159         return error;
 160 }
 161
 162 static int ravb_ptp_settime64(struct ptp_clock_info *ptp,
 163                               const struct timespec64 *ts)
 164 {
 165         struct ravb_private *priv = container_of(ptp, struct ravb_private,
 166                                                  ptp.info);
 167         unsigned long flags;
 168         int error;
 169
 170         spin_lock_irqsave(&priv->lock, flags);
 171         error = ravb_ptp_time_write(priv, ts);
 172         spin_unlock_irqrestore(&priv->lock, flags);
 173
 174         return error;
 175 }
 176
 177 static int ravb_ptp_extts(struct ptp_clock_info *ptp,
 178                           struct ptp_extts_request *req, int on)
 179 {
 180         struct ravb_private *priv = container_of(ptp, struct ravb_private,
 181                                                  ptp.info);
 182         struct net_device *ndev = priv->ndev;
 183         unsigned long flags;
 184
 185         if (req->index)
 186                 return -EINVAL;
 187
 188         if (priv->ptp.extts[req->index] == on)
 189                 return 0;
 190         priv->ptp.extts[req->index] = on;
 191
 192         spin_lock_irqsave(&priv->lock, flags);
 193         if (priv->chip_id == RCAR_GEN2)
 194                 ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
 195         else if (on)
 196                 ravb_write(ndev, GIE_PTCS, GIE);
 197         else
 198                 ravb_write(ndev, GID_PTCD, GID);
 199         mmiowb();
 200         spin_unlock_irqrestore(&priv->lock, flags);
 201
 202         return 0;
 203 }
 204
 205 static int ravb_ptp_perout(struct ptp_clock_info *ptp,
 206                            struct ptp_perout_request *req, int on)
 207 {
 208         struct ravb_private *priv = container_of(ptp, struct ravb_private,
 209                                                  ptp.info);
 210         struct net_device *ndev = priv->ndev;
 211         struct ravb_ptp_perout *perout;
 212         unsigned long flags;
 213         int error = 0;
 214
 215         if (req->index)
 216                 return -EINVAL;
 217
 218         if (on) {
 219                 u64 start_ns;
 220                 u64 period_ns;
 221
 222                 start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
 223                 period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;
 224
 225                 if (start_ns > U32_MAX) {
 226                         netdev_warn(ndev,
 227                                     "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
 228                         return -ERANGE;
 229                 }
 230
 231                 if (period_ns > U32_MAX) {
 232                         netdev_warn(ndev,
 233                                     "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
 234                         return -ERANGE;
 235                 }
 236
 237                 spin_lock_irqsave(&priv->lock, flags);
 238
 239                 perout = &priv->ptp.perout[req->index];
 240                 perout->target = (u32)start_ns;
 241                 perout->period = (u32)period_ns;
 242                 error = ravb_ptp_update_compare(priv, (u32)start_ns);
 243                 if (!error) {
 244                         /* Unmask interrupt */
 245                         if (priv->chip_id == RCAR_GEN2)
 246                                 ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
 247                         else
 248                                 ravb_write(ndev, GIE_PTMS0, GIE);
 249                 }
 250         } else  {
 251                 spin_lock_irqsave(&priv->lock, flags);
 252
 253                 perout = &priv->ptp.perout[req->index];
 254                 perout->period = 0;
 255
 256                 /* Mask interrupt */
 257                 if (priv->chip_id == RCAR_GEN2)
 258                         ravb_modify(ndev, GIC, GIC_PTME, 0);
 259                 else
 260                         ravb_write(ndev, GID_PTMD0, GID);
 261         }
 262         mmiowb();
 263         spin_unlock_irqrestore(&priv->lock, flags);
 264
 265         return error;
 266 }
 267
 268 static int ravb_ptp_enable(struct ptp_clock_info *ptp,
 269                            struct ptp_clock_request *req, int on)
 270 {
 271         switch (req->type) {
 272         case PTP_CLK_REQ_EXTTS:
 273                 return ravb_ptp_extts(ptp, &req->extts, on);
 274         case PTP_CLK_REQ_PEROUT:
 275                 return ravb_ptp_perout(ptp, &req->perout, on);
 276         default:
 277                 return -EOPNOTSUPP;
 278         }
 279 }
 280
 281 static const struct ptp_clock_info ravb_ptp_info = {
 282         .owner          = THIS_MODULE,
 283         .name           = "ravb clock",
 284         .max_adj        = 50000000,
 285         .n_ext_ts       = N_EXT_TS,
 286         .n_per_out      = N_PER_OUT,
 287         .adjfreq        = ravb_ptp_adjfreq,
 288         .adjtime        = ravb_ptp_adjtime,
 289         .gettime64      = ravb_ptp_gettime64,
 290         .settime64      = ravb_ptp_settime64,
 291         .enable         = ravb_ptp_enable,
 292 };
 293
 294 /* Caller must hold the lock */
 295 void ravb_ptp_interrupt(struct net_device *ndev)
 296 {
 297         struct ravb_private *priv = netdev_priv(ndev);
 298         u32 gis = ravb_read(ndev, GIS);
 299
 300         gis &= ravb_read(ndev, GIC);
 301         if (gis & GIS_PTCF) {
 302                 struct ptp_clock_event event;
 303
 304                 event.type = PTP_CLOCK_EXTTS;
 305                 event.index = 0;
 306                 event.timestamp = ravb_read(ndev, GCPT);
 307                 ptp_clock_event(priv->ptp.clock, &event);
 308         }
 309         if (gis & GIS_PTMF) {
 310                 struct ravb_ptp_perout *perout = priv->ptp.perout;
 311
 312                 if (perout->period) {
 313                         perout->target += perout->period;
 314                         ravb_ptp_update_compare(priv, perout->target);
 315                 }
 316         }
 317
 318         ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
 319 }
 320
 321 void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
 322 {
 323         struct ravb_private *priv = netdev_priv(ndev);
 324         unsigned long flags;
 325
 326         priv->ptp.info = ravb_ptp_info;
 327
 328         priv->ptp.default_addend = ravb_read(ndev, GTI);
 329         priv->ptp.current_addend = priv->ptp.default_addend;
 330
 331         spin_lock_irqsave(&priv->lock, flags);
 332         ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
 333         ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
 334         mmiowb();
 335         spin_unlock_irqrestore(&priv->lock, flags);
 336
 337         priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
 338 }
 339
 340 void ravb_ptp_stop(struct net_device *ndev)
 341 {
 342         struct ravb_private *priv = netdev_priv(ndev);
 343
 344         ravb_write(ndev, 0, GIC);
 345         ravb_write(ndev, 0, GIS);
 346
 347         ptp_clock_unregister(priv->ptp.clock);
 348 }