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/module.h>
   9 #include <linux/mod_devicetable.h>
  10 #include <linux/err.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/io.h>
  14 #include <linux/irq.h>
  15 #include <linux/kernel.h>
  16 #include <linux/ptp_clock_kernel.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/soc/ixp4xx/cpu.h>
  19
  20 #include "ixp46x_ts.h"
  21
  22 #define DRIVER          "ptp_ixp46x"
  23 #define N_EXT_TS        2
  24
  25 struct ixp_clock {
  26         struct ixp46x_ts_regs *regs;
  27         struct ptp_clock *ptp_clock;
  28         struct ptp_clock_info caps;
  29         int exts0_enabled;
  30         int exts1_enabled;
  31         int slave_irq;
  32         int master_irq;
  33 };
  34
  35 static DEFINE_SPINLOCK(register_lock);
  36
  37 /*
  38  * Register access functions
  39  */
  40
  41 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
  42 {
  43         u64 ns;
  44         u32 lo, hi;
  45
  46         lo = __raw_readl(&regs->systime_lo);
  47         hi = __raw_readl(&regs->systime_hi);
  48
  49         ns = ((u64) hi) << 32;
  50         ns |= lo;
  51         ns <<= TICKS_NS_SHIFT;
  52
  53         return ns;
  54 }
  55
  56 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
  57 {
  58         u32 hi, lo;
  59
  60         ns >>= TICKS_NS_SHIFT;
  61         hi = ns >> 32;
  62         lo = ns & 0xffffffff;
  63
  64         __raw_writel(lo, &regs->systime_lo);
  65         __raw_writel(hi, &regs->systime_hi);
  66 }
  67
  68 /*
  69  * Interrupt service routine
  70  */
  71
  72 static irqreturn_t isr(int irq, void *priv)
  73 {
  74         struct ixp_clock *ixp_clock = priv;
  75         struct ixp46x_ts_regs *regs = ixp_clock->regs;
  76         struct ptp_clock_event event;
  77         u32 ack = 0, lo, hi, val;
  78
  79         val = __raw_readl(&regs->event);
  80
  81         if (val & TSER_SNS) {
  82                 ack |= TSER_SNS;
  83                 if (ixp_clock->exts0_enabled) {
  84                         hi = __raw_readl(&regs->asms_hi);
  85                         lo = __raw_readl(&regs->asms_lo);
  86                         event.type = PTP_CLOCK_EXTTS;
  87                         event.index = 0;
  88                         event.timestamp = ((u64) hi) << 32;
  89                         event.timestamp |= lo;
  90                         event.timestamp <<= TICKS_NS_SHIFT;
  91                         ptp_clock_event(ixp_clock->ptp_clock, &event);
  92                 }
  93         }
  94
  95         if (val & TSER_SNM) {
  96                 ack |= TSER_SNM;
  97                 if (ixp_clock->exts1_enabled) {
  98                         hi = __raw_readl(&regs->amms_hi);
  99                         lo = __raw_readl(&regs->amms_lo);
 100                         event.type = PTP_CLOCK_EXTTS;
 101                         event.index = 1;
 102                         event.timestamp = ((u64) hi) << 32;
 103                         event.timestamp |= lo;
 104                         event.timestamp <<= TICKS_NS_SHIFT;
 105                         ptp_clock_event(ixp_clock->ptp_clock, &event);
 106                 }
 107         }
 108
 109         if (val & TTIPEND)
 110                 ack |= TTIPEND; /* this bit seems to be always set */
 111
 112         if (ack) {
 113                 __raw_writel(ack, &regs->event);
 114                 return IRQ_HANDLED;
 115         } else
 116                 return IRQ_NONE;
 117 }
 118
 119 /*
 120  * PTP clock operations
 121  */
 122
 123 static int ptp_ixp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 124 {
 125         u32 addend;
 126         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 127         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 128
 129         addend = adjust_by_scaled_ppm(DEFAULT_ADDEND, scaled_ppm);
 130
 131         __raw_writel(addend, &regs->addend);
 132
 133         return 0;
 134 }
 135
 136 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 137 {
 138         s64 now;
 139         unsigned long flags;
 140         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 141         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 142
 143         spin_lock_irqsave(&register_lock, flags);
 144
 145         now = ixp_systime_read(regs);
 146         now += delta;
 147         ixp_systime_write(regs, now);
 148
 149         spin_unlock_irqrestore(&register_lock, flags);
 150
 151         return 0;
 152 }
 153
 154 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 155 {
 156         u64 ns;
 157         unsigned long flags;
 158         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 159         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 160
 161         spin_lock_irqsave(&register_lock, flags);
 162
 163         ns = ixp_systime_read(regs);
 164
 165         spin_unlock_irqrestore(&register_lock, flags);
 166
 167         *ts = ns_to_timespec64(ns);
 168         return 0;
 169 }
 170
 171 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
 172                            const struct timespec64 *ts)
 173 {
 174         u64 ns;
 175         unsigned long flags;
 176         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 177         struct ixp46x_ts_regs *regs = ixp_clock->regs;
 178
 179         ns = timespec64_to_ns(ts);
 180
 181         spin_lock_irqsave(&register_lock, flags);
 182
 183         ixp_systime_write(regs, ns);
 184
 185         spin_unlock_irqrestore(&register_lock, flags);
 186
 187         return 0;
 188 }
 189
 190 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
 191                           struct ptp_clock_request *rq, int on)
 192 {
 193         struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
 194
 195         switch (rq->type) {
 196         case PTP_CLK_REQ_EXTTS:
 197                 switch (rq->extts.index) {
 198                 case 0:
 199                         ixp_clock->exts0_enabled = on ? 1 : 0;
 200                         break;
 201                 case 1:
 202                         ixp_clock->exts1_enabled = on ? 1 : 0;
 203                         break;
 204                 default:
 205                         return -EINVAL;
 206                 }
 207                 return 0;
 208         default:
 209                 break;
 210         }
 211
 212         return -EOPNOTSUPP;
 213 }
 214
 215 static const struct ptp_clock_info ptp_ixp_caps = {
 216         .owner          = THIS_MODULE,
 217         .name           = "IXP46X timer",
 218         .max_adj        = 66666655,
 219         .n_ext_ts       = N_EXT_TS,
 220         .n_pins         = 0,
 221         .pps            = 0,
 222         .adjfine        = ptp_ixp_adjfine,
 223         .adjtime        = ptp_ixp_adjtime,
 224         .gettime64      = ptp_ixp_gettime,
 225         .settime64      = ptp_ixp_settime,
 226         .enable         = ptp_ixp_enable,
 227 };
 228
 229 /* module operations */
 230
 231 static struct ixp_clock ixp_clock;
 232
 233 int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
 234 {
 235         *regs = ixp_clock.regs;
 236         *phc_index = ptp_clock_index(ixp_clock.ptp_clock);
 237
 238         if (!ixp_clock.ptp_clock)
 239                 return -EPROBE_DEFER;
 240
 241         return 0;
 242 }
 243 EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
 244
 245 /* Called from the registered devm action */
 246 static void ptp_ixp_unregister_action(void *d)
 247 {
 248         struct ptp_clock *ptp_clock = d;
 249
 250         ptp_clock_unregister(ptp_clock);
 251         ixp_clock.ptp_clock = NULL;
 252 }
 253
 254 static int ptp_ixp_probe(struct platform_device *pdev)
 255 {
 256         struct device *dev = &pdev->dev;
 257         int ret;
 258
 259         ixp_clock.regs = devm_platform_ioremap_resource(pdev, 0);
 260         ixp_clock.master_irq = platform_get_irq(pdev, 0);
 261         ixp_clock.slave_irq = platform_get_irq(pdev, 1);
 262         if (IS_ERR(ixp_clock.regs) ||
 263             ixp_clock.master_irq < 0 || ixp_clock.slave_irq < 0)
 264                 return -ENXIO;
 265
 266         ixp_clock.caps = ptp_ixp_caps;
 267
 268         ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
 269
 270         if (IS_ERR(ixp_clock.ptp_clock))
 271                 return PTR_ERR(ixp_clock.ptp_clock);
 272
 273         ret = devm_add_action_or_reset(dev, ptp_ixp_unregister_action,
 274                                        ixp_clock.ptp_clock);
 275         if (ret) {
 276                 dev_err(dev, "failed to install clock removal handler\n");
 277                 return ret;
 278         }
 279
 280         __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
 281         __raw_writel(1, &ixp_clock.regs->trgt_lo);
 282         __raw_writel(0, &ixp_clock.regs->trgt_hi);
 283         __raw_writel(TTIPEND, &ixp_clock.regs->event);
 284
 285         ret = devm_request_irq(dev, ixp_clock.master_irq, isr,
 286                                0, DRIVER, &ixp_clock);
 287         if (ret)
 288                 return dev_err_probe(dev, ret,
 289                                      "request_irq failed for irq %d\n",
 290                                      ixp_clock.master_irq);
 291
 292         ret = devm_request_irq(dev, ixp_clock.slave_irq, isr,
 293                                0, DRIVER, &ixp_clock);
 294         if (ret)
 295                 return dev_err_probe(dev, ret,
 296                                      "request_irq failed for irq %d\n",
 297                                      ixp_clock.slave_irq);
 298
 299         return 0;
 300 }
 301
 302 static const struct of_device_id ptp_ixp_match[] = {
 303         {
 304                 .compatible = "intel,ixp46x-ptp-timer",
 305         },
 306         { },
 307 };
 308
 309 static struct platform_driver ptp_ixp_driver = {
 310         .driver = {
 311                 .name = "ptp-ixp46x",
 312                 .of_match_table = ptp_ixp_match,
 313                 .suppress_bind_attrs = true,
 314         },
 315         .probe = ptp_ixp_probe,
 316 };
 317 module_platform_driver(ptp_ixp_driver);
 318
 319 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
 320 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
 321 MODULE_LICENSE("GPL");