drivers/net/ethernet/intel/e1000e/ptp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
   3
   4 /* PTP 1588 Hardware Clock (PHC)
   5  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
   6  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
   7  */
   8
   9 #include "e1000.h"
  10
  11 #ifdef CONFIG_E1000E_HWTS
  12 #include <linux/clocksource.h>
  13 #include <linux/ktime.h>
  14 #include <asm/tsc.h>
  15 #endif
  16
  17 /**
  18  * e1000e_phc_adjfreq - adjust the frequency of the hardware clock
  19  * @ptp: ptp clock structure
  20  * @delta: Desired frequency change in parts per billion
  21  *
  22  * Adjust the frequency of the PHC cycle counter by the indicated delta from
  23  * the base frequency.
  24  **/
  25 static int e1000e_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
  26 {
  27         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
  28                                                      ptp_clock_info);
  29         struct e1000_hw *hw = &adapter->hw;
  30         bool neg_adj = false;
  31         unsigned long flags;
  32         u64 adjustment;
  33         u32 timinca, incvalue;
  34         s32 ret_val;
  35
  36         if ((delta > ptp->max_adj) || (delta <= -1000000000))
  37                 return -EINVAL;
  38
  39         if (delta < 0) {
  40                 neg_adj = true;
  41                 delta = -delta;
  42         }
  43
  44         /* Get the System Time Register SYSTIM base frequency */
  45         ret_val = e1000e_get_base_timinca(adapter, &timinca);
  46         if (ret_val)
  47                 return ret_val;
  48
  49         spin_lock_irqsave(&adapter->systim_lock, flags);
  50
  51         incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
  52
  53         adjustment = incvalue;
  54         adjustment *= delta;
  55         adjustment = div_u64(adjustment, 1000000000);
  56
  57         incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
  58
  59         timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
  60         timinca |= incvalue;
  61
  62         ew32(TIMINCA, timinca);
  63
  64         adapter->ptp_delta = delta;
  65
  66         spin_unlock_irqrestore(&adapter->systim_lock, flags);
  67
  68         return 0;
  69 }
  70
  71 /**
  72  * e1000e_phc_adjtime - Shift the time of the hardware clock
  73  * @ptp: ptp clock structure
  74  * @delta: Desired change in nanoseconds
  75  *
  76  * Adjust the timer by resetting the timecounter structure.
  77  **/
  78 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
  79 {
  80         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
  81                                                      ptp_clock_info);
  82         unsigned long flags;
  83
  84         spin_lock_irqsave(&adapter->systim_lock, flags);
  85         timecounter_adjtime(&adapter->tc, delta);
  86         spin_unlock_irqrestore(&adapter->systim_lock, flags);
  87
  88         return 0;
  89 }
  90
  91 #ifdef CONFIG_E1000E_HWTS
  92 #define MAX_HW_WAIT_COUNT (3)
  93
  94 /**
  95  * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
  96  * @device: current device time
  97  * @system: system counter value read synchronously with device time
  98  * @ctx: context provided by timekeeping code
  99  *
 100  * Read device and system (ART) clock simultaneously and return the corrected
 101  * clock values in ns.
 102  **/
 103 static int e1000e_phc_get_syncdevicetime(ktime_t *device,
 104                                          struct system_counterval_t *system,
 105                                          void *ctx)
 106 {
 107         struct e1000_adapter *adapter = (struct e1000_adapter *)ctx;
 108         struct e1000_hw *hw = &adapter->hw;
 109         unsigned long flags;
 110         int i;
 111         u32 tsync_ctrl;
 112         u64 dev_cycles;
 113         u64 sys_cycles;
 114
 115         tsync_ctrl = er32(TSYNCTXCTL);
 116         tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
 117                 E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
 118         ew32(TSYNCTXCTL, tsync_ctrl);
 119         for (i = 0; i < MAX_HW_WAIT_COUNT; ++i) {
 120                 udelay(1);
 121                 tsync_ctrl = er32(TSYNCTXCTL);
 122                 if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
 123                         break;
 124         }
 125
 126         if (i == MAX_HW_WAIT_COUNT)
 127                 return -ETIMEDOUT;
 128
 129         dev_cycles = er32(SYSSTMPH);
 130         dev_cycles <<= 32;
 131         dev_cycles |= er32(SYSSTMPL);
 132         spin_lock_irqsave(&adapter->systim_lock, flags);
 133         *device = ns_to_ktime(timecounter_cyc2time(&adapter->tc, dev_cycles));
 134         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 135
 136         sys_cycles = er32(PLTSTMPH);
 137         sys_cycles <<= 32;
 138         sys_cycles |= er32(PLTSTMPL);
 139         *system = convert_art_to_tsc(sys_cycles);
 140
 141         return 0;
 142 }
 143
 144 /**
 145  * e1000e_phc_getsynctime - Reads the current system/device cross timestamp
 146  * @ptp: ptp clock structure
 147  * @cts: structure containing timestamp
 148  *
 149  * Read device and system (ART) clock simultaneously and return the scaled
 150  * clock values in ns.
 151  **/
 152 static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
 153                                      struct system_device_crosststamp *xtstamp)
 154 {
 155         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 156                                                      ptp_clock_info);
 157
 158         return get_device_system_crosststamp(e1000e_phc_get_syncdevicetime,
 159                                                 adapter, NULL, xtstamp);
 160 }
 161 #endif/*CONFIG_E1000E_HWTS*/
 162
 163 /**
 164  * e1000e_phc_gettime - Reads the current time from the hardware clock
 165  * @ptp: ptp clock structure
 166  * @ts: timespec structure to hold the current time value
 167  *
 168  * Read the timecounter and return the correct value in ns after converting
 169  * it into a struct timespec.
 170  **/
 171 static int e1000e_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 172 {
 173         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 174                                                      ptp_clock_info);
 175         unsigned long flags;
 176         u64 cycles, ns;
 177
 178         spin_lock_irqsave(&adapter->systim_lock, flags);
 179
 180         /* Use timecounter_cyc2time() to allow non-monotonic SYSTIM readings */
 181         cycles = adapter->cc.read(&adapter->cc);
 182         ns = timecounter_cyc2time(&adapter->tc, cycles);
 183
 184         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 185
 186         *ts = ns_to_timespec64(ns);
 187
 188         return 0;
 189 }
 190
 191 /**
 192  * e1000e_phc_settime - Set the current time on the hardware clock
 193  * @ptp: ptp clock structure
 194  * @ts: timespec containing the new time for the cycle counter
 195  *
 196  * Reset the timecounter to use a new base value instead of the kernel
 197  * wall timer value.
 198  **/
 199 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
 200                               const struct timespec64 *ts)
 201 {
 202         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 203                                                      ptp_clock_info);
 204         unsigned long flags;
 205         u64 ns;
 206
 207         ns = timespec64_to_ns(ts);
 208
 209         /* reset the timecounter */
 210         spin_lock_irqsave(&adapter->systim_lock, flags);
 211         timecounter_init(&adapter->tc, &adapter->cc, ns);
 212         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 213
 214         return 0;
 215 }
 216
 217 /**
 218  * e1000e_phc_enable - enable or disable an ancillary feature
 219  * @ptp: ptp clock structure
 220  * @request: Desired resource to enable or disable
 221  * @on: Caller passes one to enable or zero to disable
 222  *
 223  * Enable (or disable) ancillary features of the PHC subsystem.
 224  * Currently, no ancillary features are supported.
 225  **/
 226 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
 227                              struct ptp_clock_request __always_unused *request,
 228                              int __always_unused on)
 229 {
 230         return -EOPNOTSUPP;
 231 }
 232
 233 static void e1000e_systim_overflow_work(struct work_struct *work)
 234 {
 235         struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
 236                                                      systim_overflow_work.work);
 237         struct e1000_hw *hw = &adapter->hw;
 238         struct timespec64 ts;
 239         u64 ns;
 240
 241         /* Update the timecounter */
 242         ns = timecounter_read(&adapter->tc);
 243
 244         ts = ns_to_timespec64(ns);
 245         e_dbg("SYSTIM overflow check at %lld.%09lu\n",
 246               (long long) ts.tv_sec, ts.tv_nsec);
 247
 248         schedule_delayed_work(&adapter->systim_overflow_work,
 249                               E1000_SYSTIM_OVERFLOW_PERIOD);
 250 }
 251
 252 static const struct ptp_clock_info e1000e_ptp_clock_info = {
 253         .owner          = THIS_MODULE,
 254         .n_alarm        = 0,
 255         .n_ext_ts       = 0,
 256         .n_per_out      = 0,
 257         .n_pins         = 0,
 258         .pps            = 0,
 259         .adjfreq        = e1000e_phc_adjfreq,
 260         .adjtime        = e1000e_phc_adjtime,
 261         .gettime64      = e1000e_phc_gettime,
 262         .settime64      = e1000e_phc_settime,
 263         .enable         = e1000e_phc_enable,
 264 };
 265
 266 /**
 267  * e1000e_ptp_init - initialize PTP for devices which support it
 268  * @adapter: board private structure
 269  *
 270  * This function performs the required steps for enabling PTP support.
 271  * If PTP support has already been loaded it simply calls the cyclecounter
 272  * init routine and exits.
 273  **/
 274 void e1000e_ptp_init(struct e1000_adapter *adapter)
 275 {
 276         struct e1000_hw *hw = &adapter->hw;
 277
 278         adapter->ptp_clock = NULL;
 279
 280         if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
 281                 return;
 282
 283         adapter->ptp_clock_info = e1000e_ptp_clock_info;
 284
 285         snprintf(adapter->ptp_clock_info.name,
 286                  sizeof(adapter->ptp_clock_info.name), "%pm",
 287                  adapter->netdev->perm_addr);
 288
 289         switch (hw->mac.type) {
 290         case e1000_pch2lan:
 291         case e1000_pch_lpt:
 292         case e1000_pch_spt:
 293         case e1000_pch_cnp:
 294                 if ((hw->mac.type < e1000_pch_lpt) ||
 295                     (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
 296                         adapter->ptp_clock_info.max_adj = 24000000 - 1;
 297                         break;
 298                 }
 299                 /* fall-through */
 300         case e1000_82574:
 301         case e1000_82583:
 302                 adapter->ptp_clock_info.max_adj = 600000000 - 1;
 303                 break;
 304         default:
 305                 break;
 306         }
 307
 308 #ifdef CONFIG_E1000E_HWTS
 309         /* CPU must have ART and GBe must be from Sunrise Point or greater */
 310         if (hw->mac.type >= e1000_pch_spt && boot_cpu_has(X86_FEATURE_ART))
 311                 adapter->ptp_clock_info.getcrosststamp =
 312                         e1000e_phc_getcrosststamp;
 313 #endif/*CONFIG_E1000E_HWTS*/
 314
 315         INIT_DELAYED_WORK(&adapter->systim_overflow_work,
 316                           e1000e_systim_overflow_work);
 317
 318         schedule_delayed_work(&adapter->systim_overflow_work,
 319                               E1000_SYSTIM_OVERFLOW_PERIOD);
 320
 321         adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
 322                                                 &adapter->pdev->dev);
 323         if (IS_ERR(adapter->ptp_clock)) {
 324                 adapter->ptp_clock = NULL;
 325                 e_err("ptp_clock_register failed\n");
 326         } else if (adapter->ptp_clock) {
 327                 e_info("registered PHC clock\n");
 328         }
 329 }
 330
 331 /**
 332  * e1000e_ptp_remove - disable PTP device and stop the overflow check
 333  * @adapter: board private structure
 334  *
 335  * Stop the PTP support, and cancel the delayed work.
 336  **/
 337 void e1000e_ptp_remove(struct e1000_adapter *adapter)
 338 {
 339         if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
 340                 return;
 341
 342         cancel_delayed_work_sync(&adapter->systim_overflow_work);
 343
 344         if (adapter->ptp_clock) {
 345                 ptp_clock_unregister(adapter->ptp_clock);
 346                 adapter->ptp_clock = NULL;
 347                 e_info("removed PHC\n");
 348         }
 349 }