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   The full GNU General Public License is included in this distribution in
  16   the file called "COPYING".
  17
  18   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
  19   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  20 *******************************************************************************/
  21
  22 #include <linux/io.h>
  23 #include <linux/delay.h>
  24 #include "common.h"
  25 #include "stmmac_ptp.h"
  26
  27 static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
  28 {
  29         writel(data, ioaddr + PTP_TCR);
  30 }
  31
  32 static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
  33                                               u32 ptp_clock, int gmac4)
  34 {
  35         u32 value = readl(ioaddr + PTP_TCR);
  36         unsigned long data;
  37         u32 reg_value;
  38
  39         /* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
  40          *      formula = (1/ptp_clock) * 1000000000
  41          * where ptp_clock is 50MHz if fine method is used to update system
  42          */
  43         if (value & PTP_TCR_TSCFUPDT)
  44                 data = (1000000000ULL / 50000000);
  45         else
  46                 data = (1000000000ULL / ptp_clock);
  47
  48         /* 0.465ns accuracy */
  49         if (!(value & PTP_TCR_TSCTRLSSR))
  50                 data = (data * 1000) / 465;
  51
  52         data &= PTP_SSIR_SSINC_MASK;
  53
  54         reg_value = data;
  55         if (gmac4)
  56                 reg_value <<= GMAC4_PTP_SSIR_SSINC_SHIFT;
  57
  58         writel(reg_value, ioaddr + PTP_SSIR);
  59
  60         return data;
  61 }
  62
  63 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
  64 {
  65         int limit;
  66         u32 value;
  67
  68         writel(sec, ioaddr + PTP_STSUR);
  69         writel(nsec, ioaddr + PTP_STNSUR);
  70         /* issue command to initialize the system time value */
  71         value = readl(ioaddr + PTP_TCR);
  72         value |= PTP_TCR_TSINIT;
  73         writel(value, ioaddr + PTP_TCR);
  74
  75         /* wait for present system time initialize to complete */
  76         limit = 10;
  77         while (limit--) {
  78                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
  79                         break;
  80                 mdelay(10);
  81         }
  82         if (limit < 0)
  83                 return -EBUSY;
  84
  85         return 0;
  86 }
  87
  88 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
  89 {
  90         u32 value;
  91         int limit;
  92
  93         writel(addend, ioaddr + PTP_TAR);
  94         /* issue command to update the addend value */
  95         value = readl(ioaddr + PTP_TCR);
  96         value |= PTP_TCR_TSADDREG;
  97         writel(value, ioaddr + PTP_TCR);
  98
  99         /* wait for present addend update to complete */
 100         limit = 10;
 101         while (limit--) {
 102                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
 103                         break;
 104                 mdelay(10);
 105         }
 106         if (limit < 0)
 107                 return -EBUSY;
 108
 109         return 0;
 110 }
 111
 112 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
 113                                  int add_sub, int gmac4)
 114 {
 115         u32 value;
 116         int limit;
 117
 118         if (add_sub) {
 119                 /* If the new sec value needs to be subtracted with
 120                  * the system time, then MAC_STSUR reg should be
 121                  * programmed with (2^32 – <new_sec_value>)
 122                  */
 123                 if (gmac4)
 124                         sec = (100000000ULL - sec);
 125
 126                 value = readl(ioaddr + PTP_TCR);
 127                 if (value & PTP_TCR_TSCTRLSSR)
 128                         nsec = (PTP_DIGITAL_ROLLOVER_MODE - nsec);
 129                 else
 130                         nsec = (PTP_BINARY_ROLLOVER_MODE - nsec);
 131         }
 132
 133         writel(sec, ioaddr + PTP_STSUR);
 134         value = (add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec;
 135         writel(value, ioaddr + PTP_STNSUR);
 136
 137         /* issue command to initialize the system time value */
 138         value = readl(ioaddr + PTP_TCR);
 139         value |= PTP_TCR_TSUPDT;
 140         writel(value, ioaddr + PTP_TCR);
 141
 142         /* wait for present system time adjust/update to complete */
 143         limit = 10;
 144         while (limit--) {
 145                 if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
 146                         break;
 147                 mdelay(10);
 148         }
 149         if (limit < 0)
 150                 return -EBUSY;
 151
 152         return 0;
 153 }
 154
 155 static u64 stmmac_get_systime(void __iomem *ioaddr)
 156 {
 157         u64 ns;
 158
 159         /* Get the TSSS value */
 160         ns = readl(ioaddr + PTP_STNSR);
 161         /* Get the TSS and convert sec time value to nanosecond */
 162         ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
 163
 164         return ns;
 165 }
 166
 167 const struct stmmac_hwtimestamp stmmac_ptp = {
 168         .config_hw_tstamping = stmmac_config_hw_tstamping,
 169         .init_systime = stmmac_init_systime,
 170         .config_sub_second_increment = stmmac_config_sub_second_increment,
 171         .config_addend = stmmac_config_addend,
 172         .adjust_systime = stmmac_adjust_systime,
 173         .get_systime = stmmac_get_systime,
 174 };