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

   1 /*******************************************************************************
   2
   3   Intel PRO/1000 Linux driver
   4   Copyright(c) 1999 - 2013 Intel Corporation.
   5
   6   This program is free software; you can redistribute it and/or modify it
   7   under the terms and conditions of the GNU General Public License,
   8   version 2, as published by the Free Software Foundation.
   9
  10   This program is distributed in the hope it will be useful, but WITHOUT
  11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13   more details.
  14
  15   You should have received a copy of the GNU General Public License along with
  16   this program; if not, write to the Free Software Foundation, Inc.,
  17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18
  19   The full GNU General Public License is included in this distribution in
  20   the file called "COPYING".
  21
  22   Contact Information:
  23   Linux NICS <linux.nics@intel.com>
  24   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  25   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  26
  27 *******************************************************************************/
  28
  29 /* PTP 1588 Hardware Clock (PHC)
  30  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
  31  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
  32  */
  33
  34 #include "e1000.h"
  35
  36 /**
  37  * e1000e_phc_adjfreq - adjust the frequency of the hardware clock
  38  * @ptp: ptp clock structure
  39  * @delta: Desired frequency change in parts per billion
  40  *
  41  * Adjust the frequency of the PHC cycle counter by the indicated delta from
  42  * the base frequency.
  43  **/
  44 static int e1000e_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
  45 {
  46         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
  47                                                      ptp_clock_info);
  48         struct e1000_hw *hw = &adapter->hw;
  49         bool neg_adj = false;
  50         u64 adjustment;
  51         u32 timinca, incvalue;
  52         s32 ret_val;
  53
  54         if ((delta > ptp->max_adj) || (delta <= -1000000000))
  55                 return -EINVAL;
  56
  57         if (delta < 0) {
  58                 neg_adj = true;
  59                 delta = -delta;
  60         }
  61
  62         /* Get the System Time Register SYSTIM base frequency */
  63         ret_val = e1000e_get_base_timinca(adapter, &timinca);
  64         if (ret_val)
  65                 return ret_val;
  66
  67         incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
  68
  69         adjustment = incvalue;
  70         adjustment *= delta;
  71         adjustment = div_u64(adjustment, 1000000000);
  72
  73         incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
  74
  75         timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
  76         timinca |= incvalue;
  77
  78         ew32(TIMINCA, timinca);
  79
  80         return 0;
  81 }
  82
  83 /**
  84  * e1000e_phc_adjtime - Shift the time of the hardware clock
  85  * @ptp: ptp clock structure
  86  * @delta: Desired change in nanoseconds
  87  *
  88  * Adjust the timer by resetting the timecounter structure.
  89  **/
  90 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
  91 {
  92         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
  93                                                      ptp_clock_info);
  94         unsigned long flags;
  95         s64 now;
  96
  97         spin_lock_irqsave(&adapter->systim_lock, flags);
  98         now = timecounter_read(&adapter->tc);
  99         now += delta;
 100         timecounter_init(&adapter->tc, &adapter->cc, now);
 101         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 102
 103         return 0;
 104 }
 105
 106 /**
 107  * e1000e_phc_gettime - Reads the current time from the hardware clock
 108  * @ptp: ptp clock structure
 109  * @ts: timespec structure to hold the current time value
 110  *
 111  * Read the timecounter and return the correct value in ns after converting
 112  * it into a struct timespec.
 113  **/
 114 static int e1000e_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
 115 {
 116         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 117                                                      ptp_clock_info);
 118         unsigned long flags;
 119         u32 remainder;
 120         u64 ns;
 121
 122         spin_lock_irqsave(&adapter->systim_lock, flags);
 123         ns = timecounter_read(&adapter->tc);
 124         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 125
 126         ts->tv_sec = div_u64_rem(ns, NSEC_PER_SEC, &remainder);
 127         ts->tv_nsec = remainder;
 128
 129         return 0;
 130 }
 131
 132 /**
 133  * e1000e_phc_settime - Set the current time on the hardware clock
 134  * @ptp: ptp clock structure
 135  * @ts: timespec containing the new time for the cycle counter
 136  *
 137  * Reset the timecounter to use a new base value instead of the kernel
 138  * wall timer value.
 139  **/
 140 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
 141                               const struct timespec *ts)
 142 {
 143         struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 144                                                      ptp_clock_info);
 145         unsigned long flags;
 146         u64 ns;
 147
 148         ns = timespec_to_ns(ts);
 149
 150         /* reset the timecounter */
 151         spin_lock_irqsave(&adapter->systim_lock, flags);
 152         timecounter_init(&adapter->tc, &adapter->cc, ns);
 153         spin_unlock_irqrestore(&adapter->systim_lock, flags);
 154
 155         return 0;
 156 }
 157
 158 /**
 159  * e1000e_phc_enable - enable or disable an ancillary feature
 160  * @ptp: ptp clock structure
 161  * @request: Desired resource to enable or disable
 162  * @on: Caller passes one to enable or zero to disable
 163  *
 164  * Enable (or disable) ancillary features of the PHC subsystem.
 165  * Currently, no ancillary features are supported.
 166  **/
 167 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
 168                              struct ptp_clock_request __always_unused *request,
 169                              int __always_unused on)
 170 {
 171         return -EOPNOTSUPP;
 172 }
 173
 174 static void e1000e_systim_overflow_work(struct work_struct *work)
 175 {
 176         struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
 177                                                      systim_overflow_work.work);
 178         struct e1000_hw *hw = &adapter->hw;
 179         struct timespec ts;
 180
 181         adapter->ptp_clock_info.gettime(&adapter->ptp_clock_info, &ts);
 182
 183         e_dbg("SYSTIM overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
 184
 185         schedule_delayed_work(&adapter->systim_overflow_work,
 186                               E1000_SYSTIM_OVERFLOW_PERIOD);
 187 }
 188
 189 static const struct ptp_clock_info e1000e_ptp_clock_info = {
 190         .owner          = THIS_MODULE,
 191         .n_alarm        = 0,
 192         .n_ext_ts       = 0,
 193         .n_per_out      = 0,
 194         .pps            = 0,
 195         .adjfreq        = e1000e_phc_adjfreq,
 196         .adjtime        = e1000e_phc_adjtime,
 197         .gettime        = e1000e_phc_gettime,
 198         .settime        = e1000e_phc_settime,
 199         .enable         = e1000e_phc_enable,
 200 };
 201
 202 /**
 203  * e1000e_ptp_init - initialize PTP for devices which support it
 204  * @adapter: board private structure
 205  *
 206  * This function performs the required steps for enabling PTP support.
 207  * If PTP support has already been loaded it simply calls the cyclecounter
 208  * init routine and exits.
 209  **/
 210 void e1000e_ptp_init(struct e1000_adapter *adapter)
 211 {
 212         struct e1000_hw *hw = &adapter->hw;
 213
 214         adapter->ptp_clock = NULL;
 215
 216         if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
 217                 return;
 218
 219         adapter->ptp_clock_info = e1000e_ptp_clock_info;
 220
 221         snprintf(adapter->ptp_clock_info.name,
 222                  sizeof(adapter->ptp_clock_info.name), "%pm",
 223                  adapter->netdev->perm_addr);
 224
 225         switch (hw->mac.type) {
 226         case e1000_pch2lan:
 227         case e1000_pch_lpt:
 228                 if ((hw->mac.type != e1000_pch_lpt) ||
 229                     (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
 230                         adapter->ptp_clock_info.max_adj = 24000000 - 1;
 231                         break;
 232                 }
 233                 /* fall-through */
 234         case e1000_82574:
 235         case e1000_82583:
 236                 adapter->ptp_clock_info.max_adj = 600000000 - 1;
 237                 break;
 238         default:
 239                 break;
 240         }
 241
 242         INIT_DELAYED_WORK(&adapter->systim_overflow_work,
 243                           e1000e_systim_overflow_work);
 244
 245         schedule_delayed_work(&adapter->systim_overflow_work,
 246                               E1000_SYSTIM_OVERFLOW_PERIOD);
 247
 248         adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
 249                                                 &adapter->pdev->dev);
 250         if (IS_ERR(adapter->ptp_clock)) {
 251                 adapter->ptp_clock = NULL;
 252                 e_err("ptp_clock_register failed\n");
 253         } else {
 254                 e_info("registered PHC clock\n");
 255         }
 256 }
 257
 258 /**
 259  * e1000e_ptp_remove - disable PTP device and stop the overflow check
 260  * @adapter: board private structure
 261  *
 262  * Stop the PTP support, and cancel the delayed work.
 263  **/
 264 void e1000e_ptp_remove(struct e1000_adapter *adapter)
 265 {
 266         if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
 267                 return;
 268
 269         cancel_delayed_work_sync(&adapter->systim_overflow_work);
 270
 271         if (adapter->ptp_clock) {
 272                 ptp_clock_unregister(adapter->ptp_clock);
 273                 adapter->ptp_clock = NULL;
 274                 e_info("removed PHC\n");
 275         }
 276 }