drivers/net/ethernet/renesas/rcar_gen4_ptp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Renesas R-Car Gen4 gPTP device driver
   3  *
   4  * Copyright (C) 2022 Renesas Electronics Corporation
   5  */
   6
   7 #include <linux/err.h>
   8 #include <linux/etherdevice.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13
  14 #include "rcar_gen4_ptp.h"
  15 #define ptp_to_priv(ptp)        container_of(ptp, struct rcar_gen4_ptp_private, info)
  16
  17 static const struct rcar_gen4_ptp_reg_offset gen4_offs = {
  18         .enable = PTPTMEC,
  19         .disable = PTPTMDC,
  20         .increment = PTPTIVC0,
  21         .config_t0 = PTPTOVC00,
  22         .config_t1 = PTPTOVC10,
  23         .config_t2 = PTPTOVC20,
  24         .monitor_t0 = PTPGPTPTM00,
  25         .monitor_t1 = PTPGPTPTM10,
  26         .monitor_t2 = PTPGPTPTM20,
  27 };
  28
  29 static int rcar_gen4_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
  30 {
  31         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
  32         bool neg_adj = scaled_ppm < 0 ? true : false;
  33         s64 addend = ptp_priv->default_addend;
  34         s64 diff;
  35
  36         if (neg_adj)
  37                 scaled_ppm = -scaled_ppm;
  38         diff = div_s64(addend * scaled_ppm_to_ppb(scaled_ppm), NSEC_PER_SEC);
  39         addend = neg_adj ? addend - diff : addend + diff;
  40
  41         iowrite32(addend, ptp_priv->addr + ptp_priv->offs->increment);
  42
  43         return 0;
  44 }
  45
  46 /* Caller must hold the lock */
  47 static void _rcar_gen4_ptp_gettime(struct ptp_clock_info *ptp,
  48                                    struct timespec64 *ts)
  49 {
  50         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
  51
  52         ts->tv_nsec = ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t0);
  53         ts->tv_sec = ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t1) |
  54                      ((s64)ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t2) << 32);
  55 }
  56
  57 static int rcar_gen4_ptp_gettime(struct ptp_clock_info *ptp,
  58                                  struct timespec64 *ts)
  59 {
  60         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
  61         unsigned long flags;
  62
  63         spin_lock_irqsave(&ptp_priv->lock, flags);
  64         _rcar_gen4_ptp_gettime(ptp, ts);
  65         spin_unlock_irqrestore(&ptp_priv->lock, flags);
  66
  67         return 0;
  68 }
  69
  70 /* Caller must hold the lock */
  71 static void _rcar_gen4_ptp_settime(struct ptp_clock_info *ptp,
  72                                    const struct timespec64 *ts)
  73 {
  74         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
  75
  76         iowrite32(1, ptp_priv->addr + ptp_priv->offs->disable);
  77         iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t2);
  78         iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t1);
  79         iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t0);
  80         iowrite32(1, ptp_priv->addr + ptp_priv->offs->enable);
  81         iowrite32(ts->tv_sec >> 32, ptp_priv->addr + ptp_priv->offs->config_t2);
  82         iowrite32(ts->tv_sec, ptp_priv->addr + ptp_priv->offs->config_t1);
  83         iowrite32(ts->tv_nsec, ptp_priv->addr + ptp_priv->offs->config_t0);
  84 }
  85
  86 static int rcar_gen4_ptp_settime(struct ptp_clock_info *ptp,
  87                                  const struct timespec64 *ts)
  88 {
  89         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
  90         unsigned long flags;
  91
  92         spin_lock_irqsave(&ptp_priv->lock, flags);
  93         _rcar_gen4_ptp_settime(ptp, ts);
  94         spin_unlock_irqrestore(&ptp_priv->lock, flags);
  95
  96         return 0;
  97 }
  98
  99 static int rcar_gen4_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 100 {
 101         struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
 102         struct timespec64 ts;
 103         unsigned long flags;
 104         s64 now;
 105
 106         spin_lock_irqsave(&ptp_priv->lock, flags);
 107         _rcar_gen4_ptp_gettime(ptp, &ts);
 108         now = ktime_to_ns(timespec64_to_ktime(ts));
 109         ts = ns_to_timespec64(now + delta);
 110         _rcar_gen4_ptp_settime(ptp, &ts);
 111         spin_unlock_irqrestore(&ptp_priv->lock, flags);
 112
 113         return 0;
 114 }
 115
 116 static int rcar_gen4_ptp_enable(struct ptp_clock_info *ptp,
 117                                 struct ptp_clock_request *rq, int on)
 118 {
 119         return -EOPNOTSUPP;
 120 }
 121
 122 static struct ptp_clock_info rcar_gen4_ptp_info = {
 123         .owner = THIS_MODULE,
 124         .name = "rcar_gen4_ptp",
 125         .max_adj = 50000000,
 126         .adjfine = rcar_gen4_ptp_adjfine,
 127         .adjtime = rcar_gen4_ptp_adjtime,
 128         .gettime64 = rcar_gen4_ptp_gettime,
 129         .settime64 = rcar_gen4_ptp_settime,
 130         .enable = rcar_gen4_ptp_enable,
 131 };
 132
 133 static int rcar_gen4_ptp_set_offs(struct rcar_gen4_ptp_private *ptp_priv,
 134                                   enum rcar_gen4_ptp_reg_layout layout)
 135 {
 136         if (layout != RCAR_GEN4_PTP_REG_LAYOUT)
 137                 return -EINVAL;
 138
 139         ptp_priv->offs = &gen4_offs;
 140
 141         return 0;
 142 }
 143
 144 static s64 rcar_gen4_ptp_rate_to_increment(u32 rate)
 145 {
 146         /* Timer increment in ns.
 147          * bit[31:27] - integer
 148          * bit[26:0]  - decimal
 149          * increment[ns] = perid[ns] * 2^27 => (1ns * 2^27) / rate[hz]
 150          */
 151         return div_s64(1000000000LL << 27, rate);
 152 }
 153
 154 int rcar_gen4_ptp_register(struct rcar_gen4_ptp_private *ptp_priv,
 155                            enum rcar_gen4_ptp_reg_layout layout, u32 rate)
 156 {
 157         int ret;
 158
 159         if (ptp_priv->initialized)
 160                 return 0;
 161
 162         spin_lock_init(&ptp_priv->lock);
 163
 164         ret = rcar_gen4_ptp_set_offs(ptp_priv, layout);
 165         if (ret)
 166                 return ret;
 167
 168         ptp_priv->default_addend = rcar_gen4_ptp_rate_to_increment(rate);
 169         iowrite32(ptp_priv->default_addend, ptp_priv->addr + ptp_priv->offs->increment);
 170         ptp_priv->clock = ptp_clock_register(&ptp_priv->info, NULL);
 171         if (IS_ERR(ptp_priv->clock))
 172                 return PTR_ERR(ptp_priv->clock);
 173
 174         iowrite32(0x01, ptp_priv->addr + ptp_priv->offs->enable);
 175         ptp_priv->initialized = true;
 176
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(rcar_gen4_ptp_register);
 180
 181 int rcar_gen4_ptp_unregister(struct rcar_gen4_ptp_private *ptp_priv)
 182 {
 183         iowrite32(1, ptp_priv->addr + ptp_priv->offs->disable);
 184
 185         return ptp_clock_unregister(ptp_priv->clock);
 186 }
 187 EXPORT_SYMBOL_GPL(rcar_gen4_ptp_unregister);
 188
 189 struct rcar_gen4_ptp_private *rcar_gen4_ptp_alloc(struct platform_device *pdev)
 190 {
 191         struct rcar_gen4_ptp_private *ptp;
 192
 193         ptp = devm_kzalloc(&pdev->dev, sizeof(*ptp), GFP_KERNEL);
 194         if (!ptp)
 195                 return NULL;
 196
 197         ptp->info = rcar_gen4_ptp_info;
 198
 199         return ptp;
 200 }
 201 EXPORT_SYMBOL_GPL(rcar_gen4_ptp_alloc);
 202
 203 MODULE_AUTHOR("Yoshihiro Shimoda");
 204 MODULE_DESCRIPTION("Renesas R-Car Gen4 gPTP driver");
 205 MODULE_LICENSE("GPL");