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 void stmmac_config_sub_second_increment(void __iomem *ioaddr)
  37 {
  38         u32 value = readl(ioaddr + PTP_TCR);
  39         unsigned long data;
  40
  41         /* Convert the ptp_clock to nano second
  42          * formula = (1/ptp_clock) * 1000000000
  43          * where, ptp_clock = 50MHz.
  44          */
  45         data = (1000000000ULL / 50000000);
  46
  47         /* 0.465ns accuracy */
  48         if (!(value & PTP_TCR_TSCTRLSSR))
  49                 data = (data * 1000) / 465;
  50
  51         writel(data, ioaddr + PTP_SSIR);
  52 }
  53
  54 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
  55 {
  56         int limit;
  57         u32 value;
  58
  59         writel(sec, ioaddr + PTP_STSUR);
  60         writel(nsec, ioaddr + PTP_STNSUR);
  61         /* issue command to initialize the system time value */
  62         value = readl(ioaddr + PTP_TCR);
  63         value |= PTP_TCR_TSINIT;
  64         writel(value, ioaddr + PTP_TCR);
  65
  66         /* wait for present system time initialize to complete */
  67         limit = 10;
  68         while (limit--) {
  69                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
  70                         break;
  71                 mdelay(10);
  72         }
  73         if (limit < 0)
  74                 return -EBUSY;
  75
  76         return 0;
  77 }
  78
  79 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
  80 {
  81         u32 value;
  82         int limit;
  83
  84         writel(addend, ioaddr + PTP_TAR);
  85         /* issue command to update the addend value */
  86         value = readl(ioaddr + PTP_TCR);
  87         value |= PTP_TCR_TSADDREG;
  88         writel(value, ioaddr + PTP_TCR);
  89
  90         /* wait for present addend update to complete */
  91         limit = 10;
  92         while (limit--) {
  93                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
  94                         break;
  95                 mdelay(10);
  96         }
  97         if (limit < 0)
  98                 return -EBUSY;
  99
 100         return 0;
 101 }
 102
 103 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
 104                                  int add_sub)
 105 {
 106         u32 value;
 107         int limit;
 108
 109         writel(sec, ioaddr + PTP_STSUR);
 110         writel(((add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec),
 111                 ioaddr + PTP_STNSUR);
 112         /* issue command to initialize the system time value */
 113         value = readl(ioaddr + PTP_TCR);
 114         value |= PTP_TCR_TSUPDT;
 115         writel(value, ioaddr + PTP_TCR);
 116
 117         /* wait for present system time adjust/update to complete */
 118         limit = 10;
 119         while (limit--) {
 120                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
 121                         break;
 122                 mdelay(10);
 123         }
 124         if (limit < 0)
 125                 return -EBUSY;
 126
 127         return 0;
 128 }
 129
 130 static u64 stmmac_get_systime(void __iomem *ioaddr)
 131 {
 132         u64 ns;
 133
 134         ns = readl(ioaddr + PTP_STNSR);
 135         /* convert sec time value to nanosecond */
 136         ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
 137
 138         return ns;
 139 }
 140
 141 const struct stmmac_hwtimestamp stmmac_ptp = {
 142         .config_hw_tstamping = stmmac_config_hw_tstamping,
 143         .init_systime = stmmac_init_systime,
 144         .config_sub_second_increment = stmmac_config_sub_second_increment,
 145         .config_addend = stmmac_config_addend,
 146         .adjust_systime = stmmac_adjust_systime,
 147         .get_systime = stmmac_get_systime,
 148 };