drivers/net/ethernet/xscale/ptp_ixp46x.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * PTP 1588 clock using the IXP46X
   4  *
   5  * Copyright (C) 2010 OMICRON electronics GmbH
   6  */
   7 #include <linux/device.h>
   8 #include <linux/err.h>
   9 #include <linux/gpio.h>
  10 #include <linux/init.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/irq.h>
  14 #include <linux/kernel.h>
  15 #include <linux/ptp_clock_kernel.h>
  16 #include <linux/soc/ixp4xx/cpu.h>
  17 #include <linux/module.h>
  18 #include <mach/ixp4xx-regs.h>
  19
  20 #include "ixp46x_ts.h"
  21
  22 #define DRIVER          "ptp_ixp46x"
  23 #define N_EXT_TS        2
  24 #define MASTER_GPIO     8
  25 #define MASTER_IRQ      25
  26 #define SLAVE_GPIO      7
  27 #define SLAVE_IRQ       24
  28
  29 struct ixp_clock {
  30         struct ixp46x_ts_regs *regs;
  31         struct ptp_clock *ptp_clock;
  32         struct ptp_clock_info caps;
  33         int exts0_enabled;
  34         int exts1_enabled;
  35 };
  36
  37 DEFINE_SPINLOCK(register_lock);
  38
  39 /*
  40  * Register access functions
  41  */
  42
  43 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
  44 {
  45         u64 ns;
  46         u32 lo, hi;
  47
  48         lo = __raw_readl(&regs->systime_lo);
  49         hi = __raw_readl(&regs->systime_hi);
  50
  51         ns = ((u64) hi) << 32;
  52         ns |= lo;
  53         ns <<= TICKS_NS_SHIFT;
  54
  55         return ns;
  56 }
  57
  58 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
  59 {
  60         u32 hi, lo;
  61
  62         ns >>= TICKS_NS_SHIFT;
  63         hi = ns >> 32;
  64         lo = ns & 0xffffffff;
  65
  66         __raw_writel(lo, &regs->systime_lo);
  67         __raw_writel(hi, &regs->systime_hi);
  68 }
  69
  70 /*
  71  * Interrupt service routine
  72  */
  73
  74 static irqreturn_t isr(int irq, void *priv)
  75 {
  76         struct ixp_clock *ixp_clock = priv;
  77         struct ixp46x_ts_regs *regs = ixp_clock->regs;
  78         struct ptp_clock_event event;
  79         u32 ack = 0, lo, hi, val;
  80
  81         val = __raw_readl(&regs->event);
  82
  83         if (val & TSER_SNS) {
  84                 ack |= TSER_SNS;
  85                 if (ixp_clock->exts0_enabled) {
  86                         hi = __raw_readl(&regs->asms_hi);
  87                         lo = __raw_readl(&regs->asms_lo);
  88                         event.type = PTP_CLOCK_EXTTS;
  89                         event.index = 0;
  90                         event.timestamp = ((u64) hi) << 32;
  91                         event.timestamp |= lo;
  92                         event.timestamp <<= TICKS_NS_SHIFT;
  93                         ptp_clock_event(ixp_clock->ptp_clock, &event);
  94                 }
  95         }
  96
  97         if (val & TSER_SNM) {
  98                 ack |= TSER_SNM;
  99                 if (ixp_clock->exts1_enabled) {
 100                         hi = __raw_readl(&regs->amms_hi);
 101                         lo = __raw_readl(&regs->amms_lo);
 102                         event.type = PTP_CLOCK_EXTTS;
 103                         event.index = 1;
 104                         event.timestamp = ((u64) hi) << 32;
 105                         event.timestamp |= lo;
 106                         event.timestamp <<= TICKS_NS_SHIFT;
 107                         ptp_clock_event(ixp_clock->ptp_clock, &event);
 108                 }
 109         }
 110
 111         if (val & TTIPEND)
 112                 ack |= TTIPEND; /* this bit seems to be always set */
 113
 114         if (ack) {
 115                 __raw_writel(ack, &regs->event);
 116                 return IRQ_HANDLED;
 117         } else
 118                 return IRQ_NONE;
 119 }
 120
 121 /*
 122  * PTP clock operations
 123  */
 124
 125 static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 126 {
 127         u64 adj;
 128         u32 diff, addend;
 129         int neg_adj = 0;
 130         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 131         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 132
 133         if (ppb < 0) {
 134                 neg_adj = 1;
 135                 ppb = -ppb;
 136         }
 137         addend = DEFAULT_ADDEND;
 138         adj = addend;
 139         adj *= ppb;
 140         diff = div_u64(adj, 1000000000ULL);
 141
 142         addend = neg_adj ? addend - diff : addend + diff;
 143
 144         __raw_writel(addend, &regs->addend);
 145
 146         return 0;
 147 }
 148
 149 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 150 {
 151         s64 now;
 152         unsigned long flags;
 153         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 154         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 155
 156         spin_lock_irqsave(&register_lock, flags);
 157
 158         now = ixp_systime_read(regs);
 159         now += delta;
 160         ixp_systime_write(regs, now);
 161
 162         spin_unlock_irqrestore(&register_lock, flags);
 163
 164         return 0;
 165 }
 166
 167 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 168 {
 169         u64 ns;
 170         unsigned long flags;
 171         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 172         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 173
 174         spin_lock_irqsave(&register_lock, flags);
 175
 176         ns = ixp_systime_read(regs);
 177
 178         spin_unlock_irqrestore(&register_lock, flags);
 179
 180         *ts = ns_to_timespec64(ns);
 181         return 0;
 182 }
 183
 184 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
 185                            const struct timespec64 *ts)
 186 {
 187         u64 ns;
 188         unsigned long flags;
 189         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 190         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 191
 192         ns = timespec64_to_ns(ts);
 193
 194         spin_lock_irqsave(&register_lock, flags);
 195
 196         ixp_systime_write(regs, ns);
 197
 198         spin_unlock_irqrestore(&register_lock, flags);
 199
 200         return 0;
 201 }
 202
 203 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
 204                           struct ptp_clock_request *rq, int on)
 205 {
 206         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 207
 208         switch (rq->type) {
 209         case PTP_CLK_REQ_EXTTS:
 210                 switch (rq->extts.index) {
 211                 case 0:
 212                         ixp_clock->exts0_enabled = on ? 1 : 0;
 213                         break;
 214                 case 1:
 215                         ixp_clock->exts1_enabled = on ? 1 : 0;
 216                         break;
 217                 default:
 218                         return -EINVAL;
 219                 }
 220                 return 0;
 221         default:
 222                 break;
 223         }
 224
 225         return -EOPNOTSUPP;
 226 }
 227
 228 static const struct ptp_clock_info ptp_ixp_caps = {
 229         .owner          = THIS_MODULE,
 230         .name           = "IXP46X timer",
 231         .max_adj        = 66666655,
 232         .n_ext_ts       = N_EXT_TS,
 233         .n_pins         = 0,
 234         .pps            = 0,
 235         .adjfreq        = ptp_ixp_adjfreq,
 236         .adjtime        = ptp_ixp_adjtime,
 237         .gettime64      = ptp_ixp_gettime,
 238         .settime64      = ptp_ixp_settime,
 239         .enable         = ptp_ixp_enable,
 240 };
 241
 242 /* module operations */
 243
 244 static struct ixp_clock ixp_clock;
 245
 246 static int setup_interrupt(int gpio)
 247 {
 248         int irq;
 249         int err;
 250
 251         err = gpio_request(gpio, "ixp4-ptp");
 252         if (err)
 253                 return err;
 254
 255         err = gpio_direction_input(gpio);
 256         if (err)
 257                 return err;
 258
 259         irq = gpio_to_irq(gpio);
 260         if (irq < 0)
 261                 return irq;
 262
 263         err = irq_set_irq_type(irq, IRQF_TRIGGER_FALLING);
 264         if (err) {
 265                 pr_err("cannot set trigger type for irq %d\n", irq);
 266                 return err;
 267         }
 268
 269         err = request_irq(irq, isr, 0, DRIVER, &ixp_clock);
 270         if (err) {
 271                 pr_err("request_irq failed for irq %d\n", irq);
 272                 return err;
 273         }
 274
 275         return irq;
 276 }
 277
 278 static void __exit ptp_ixp_exit(void)
 279 {
 280         free_irq(MASTER_IRQ, &ixp_clock);
 281         free_irq(SLAVE_IRQ, &ixp_clock);
 282         ixp46x_phc_index = -1;
 283         ptp_clock_unregister(ixp_clock.ptp_clock);
 284 }
 285
 286 static int __init ptp_ixp_init(void)
 287 {
 288         if (!cpu_is_ixp46x())
 289                 return -ENODEV;
 290
 291         ixp_clock.regs =
 292                 (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
 293
 294         ixp_clock.caps = ptp_ixp_caps;
 295
 296         ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
 297
 298         if (IS_ERR(ixp_clock.ptp_clock))
 299                 return PTR_ERR(ixp_clock.ptp_clock);
 300
 301         ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
 302
 303         __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
 304         __raw_writel(1, &ixp_clock.regs->trgt_lo);
 305         __raw_writel(0, &ixp_clock.regs->trgt_hi);
 306         __raw_writel(TTIPEND, &ixp_clock.regs->event);
 307
 308         if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
 309                 pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
 310                 goto no_master;
 311         }
 312         if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
 313                 pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
 314                 goto no_slave;
 315         }
 316
 317         return 0;
 318 no_slave:
 319         free_irq(MASTER_IRQ, &ixp_clock);
 320 no_master:
 321         ptp_clock_unregister(ixp_clock.ptp_clock);
 322         return -ENODEV;
 323 }
 324
 325 module_init(ptp_ixp_init);
 326 module_exit(ptp_ixp_exit);
 327
 328 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
 329 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
 330 MODULE_LICENSE("GPL");