drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c

   1 /*******************************************************************************
   2   Copyright (C) 2013  Vayavya Labs Pvt Ltd
   3
   4   This implements all the API for managing HW timestamp & PTP.
   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   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
  23   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  24 *******************************************************************************/
  25
  26 #include <linux/io.h>
  27 #include <linux/delay.h>
  28 #include "common.h"
  29 #include "stmmac_ptp.h"
  30
  31 static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
  32 {
  33         writel(data, ioaddr + PTP_TCR);
  34 }
  35
  36 static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
  37                                               u32 ptp_clock)
  38 {
  39         u32 value = readl(ioaddr + PTP_TCR);
  40         unsigned long data;
  41
  42         /* Convert the ptp_clock to nano second
  43          * formula = (2/ptp_clock) * 1000000000
  44          * where, ptp_clock = 50MHz.
  45          */
  46         data = (2000000000ULL / ptp_clock);
  47
  48         /* 0.465ns accuracy */
  49         if (!(value & PTP_TCR_TSCTRLSSR))
  50                 data = (data * 1000) / 465;
  51
  52         writel(data, ioaddr + PTP_SSIR);
  53
  54         return data;
  55 }
  56
  57 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
  58 {
  59         int limit;
  60         u32 value;
  61
  62         writel(sec, ioaddr + PTP_STSUR);
  63         writel(nsec, ioaddr + PTP_STNSUR);
  64         /* issue command to initialize the system time value */
  65         value = readl(ioaddr + PTP_TCR);
  66         value |= PTP_TCR_TSINIT;
  67         writel(value, ioaddr + PTP_TCR);
  68
  69         /* wait for present system time initialize to complete */
  70         limit = 10;
  71         while (limit--) {
  72                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
  73                         break;
  74                 mdelay(10);
  75         }
  76         if (limit < 0)
  77                 return -EBUSY;
  78
  79         return 0;
  80 }
  81
  82 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
  83 {
  84         u32 value;
  85         int limit;
  86
  87         writel(addend, ioaddr + PTP_TAR);
  88         /* issue command to update the addend value */
  89         value = readl(ioaddr + PTP_TCR);
  90         value |= PTP_TCR_TSADDREG;
  91         writel(value, ioaddr + PTP_TCR);
  92
  93         /* wait for present addend update to complete */
  94         limit = 10;
  95         while (limit--) {
  96                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
  97                         break;
  98                 mdelay(10);
  99         }
 100         if (limit < 0)
 101                 return -EBUSY;
 102
 103         return 0;
 104 }
 105
 106 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
 107                                  int add_sub)
 108 {
 109         u32 value;
 110         int limit;
 111
 112         writel(sec, ioaddr + PTP_STSUR);
 113         writel(((add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec),
 114                 ioaddr + PTP_STNSUR);
 115         /* issue command to initialize the system time value */
 116         value = readl(ioaddr + PTP_TCR);
 117         value |= PTP_TCR_TSUPDT;
 118         writel(value, ioaddr + PTP_TCR);
 119
 120         /* wait for present system time adjust/update to complete */
 121         limit = 10;
 122         while (limit--) {
 123                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
 124                         break;
 125                 mdelay(10);
 126         }
 127         if (limit < 0)
 128                 return -EBUSY;
 129
 130         return 0;
 131 }
 132
 133 static u64 stmmac_get_systime(void __iomem *ioaddr)
 134 {
 135         u64 ns;
 136
 137         ns = readl(ioaddr + PTP_STNSR);
 138         /* convert sec time value to nanosecond */
 139         ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
 140
 141         return ns;
 142 }
 143
 144 const struct stmmac_hwtimestamp stmmac_ptp = {
 145         .config_hw_tstamping = stmmac_config_hw_tstamping,
 146         .init_systime = stmmac_init_systime,
 147         .config_sub_second_increment = stmmac_config_sub_second_increment,
 148         .config_addend = stmmac_config_addend,
 149         .adjust_systime = stmmac_adjust_systime,
 150         .get_systime = stmmac_get_systime,
 151 };