1 // SPDX-License-Identifier: GPL-2.0
3 * Fast Ethernet Controller (ENET) PTP driver for MX6x.
5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/ptrace.h>
14 #include <linux/errno.h>
15 #include <linux/ioport.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/pci.h>
19 #include <linux/delay.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/spinlock.h>
24 #include <linux/workqueue.h>
25 #include <linux/bitops.h>
27 #include <linux/irq.h>
28 #include <linux/clk.h>
29 #include <linux/platform_device.h>
30 #include <linux/phy.h>
31 #include <linux/fec.h>
33 #include <linux/of_device.h>
34 #include <linux/of_gpio.h>
35 #include <linux/of_net.h>
39 /* FEC 1588 register bits */
40 #define FEC_T_CTRL_SLAVE 0x00002000
41 #define FEC_T_CTRL_CAPTURE 0x00000800
42 #define FEC_T_CTRL_RESTART 0x00000200
43 #define FEC_T_CTRL_PERIOD_RST 0x00000030
44 #define FEC_T_CTRL_PERIOD_EN 0x00000010
45 #define FEC_T_CTRL_ENABLE 0x00000001
47 #define FEC_T_INC_MASK 0x0000007f
48 #define FEC_T_INC_OFFSET 0
49 #define FEC_T_INC_CORR_MASK 0x00007f00
50 #define FEC_T_INC_CORR_OFFSET 8
52 #define FEC_T_CTRL_PINPER 0x00000080
53 #define FEC_T_TF0_MASK 0x00000001
54 #define FEC_T_TF0_OFFSET 0
55 #define FEC_T_TF1_MASK 0x00000002
56 #define FEC_T_TF1_OFFSET 1
57 #define FEC_T_TF2_MASK 0x00000004
58 #define FEC_T_TF2_OFFSET 2
59 #define FEC_T_TF3_MASK 0x00000008
60 #define FEC_T_TF3_OFFSET 3
61 #define FEC_T_TDRE_MASK 0x00000001
62 #define FEC_T_TDRE_OFFSET 0
63 #define FEC_T_TMODE_MASK 0x0000003C
64 #define FEC_T_TMODE_OFFSET 2
65 #define FEC_T_TIE_MASK 0x00000040
66 #define FEC_T_TIE_OFFSET 6
67 #define FEC_T_TF_MASK 0x00000080
68 #define FEC_T_TF_OFFSET 7
70 #define FEC_ATIME_CTRL 0x400
71 #define FEC_ATIME 0x404
72 #define FEC_ATIME_EVT_OFFSET 0x408
73 #define FEC_ATIME_EVT_PERIOD 0x40c
74 #define FEC_ATIME_CORR 0x410
75 #define FEC_ATIME_INC 0x414
76 #define FEC_TS_TIMESTAMP 0x418
78 #define FEC_TGSR 0x604
79 #define FEC_TCSR(n) (0x608 + n * 0x08)
80 #define FEC_TCCR(n) (0x60C + n * 0x08)
81 #define MAX_TIMER_CHANNEL 3
82 #define FEC_TMODE_TOGGLE 0x05
83 #define FEC_HIGH_PULSE 0x0F
85 #define FEC_CC_MULT (1 << 31)
86 #define FEC_COUNTER_PERIOD (1 << 31)
87 #define PPS_OUPUT_RELOAD_PERIOD NSEC_PER_SEC
88 #define FEC_CHANNLE_0 0
89 #define DEFAULT_PPS_CHANNEL FEC_CHANNLE_0
93 * @fep: the fec_enet_private structure handle
94 * @enable: enable the channel pps output
96 * This function enble the PPS ouput on the timer channel.
98 static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
102 struct timespec64 ts;
105 if (fep->pps_enable == enable)
108 fep->pps_channel = DEFAULT_PPS_CHANNEL;
109 fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
111 spin_lock_irqsave(&fep->tmreg_lock, flags);
114 /* clear capture or output compare interrupt status if have.
116 writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
118 /* It is recommended to double check the TMODE field in the
119 * TCSR register to be cleared before the first compare counter
120 * is written into TCCR register. Just add a double check.
122 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
124 val &= ~(FEC_T_TMODE_MASK);
125 writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
126 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
127 } while (val & FEC_T_TMODE_MASK);
129 /* Dummy read counter to update the counter */
130 timecounter_read(&fep->tc);
131 /* We want to find the first compare event in the next
132 * second point. So we need to know what the ptp time
133 * is now and how many nanoseconds is ahead to get next second.
134 * The remaining nanosecond ahead before the next second would be
135 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
136 * to current timer would be next second.
138 tempval = fep->cc.read(&fep->cc);
139 /* Convert the ptp local counter to 1588 timestamp */
140 ns = timecounter_cyc2time(&fep->tc, tempval);
141 ts = ns_to_timespec64(ns);
143 /* The tempval is less than 3 seconds, and so val is less than
144 * 4 seconds. No overflow for 32bit calculation.
146 val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
148 /* Need to consider the situation that the current time is
149 * very close to the second point, which means NSEC_PER_SEC
150 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
151 * is still running when we calculate the first compare event, it is
152 * possible that the remaining nanoseonds run out before the compare
153 * counter is calculated and written into TCCR register. To avoid
154 * this possibility, we will set the compare event to be the next
155 * of next second. The current setting is 31-bit timer and wrap
156 * around over 2 seconds. So it is okay to set the next of next
157 * seond for the timer.
161 /* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
162 * ptp counter, which maybe cause 32-bit wrap. Since the
163 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
164 * We can ensure the wrap will not cause issue. If the offset
165 * is bigger than fep->cc.mask would be a error.
168 writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
170 /* Calculate the second the compare event timestamp */
171 fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
173 /* * Enable compare event when overflow */
174 val = readl(fep->hwp + FEC_ATIME_CTRL);
175 val |= FEC_T_CTRL_PINPER;
176 writel(val, fep->hwp + FEC_ATIME_CTRL);
178 /* Compare channel setting. */
179 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
180 val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
181 val &= ~(1 << FEC_T_TDRE_OFFSET);
182 val &= ~(FEC_T_TMODE_MASK);
183 val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
184 writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
186 /* Write the second compare event timestamp and calculate
187 * the third timestamp. Refer the TCCR register detail in the spec.
189 writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
190 fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
192 writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
195 fep->pps_enable = enable;
196 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
202 * fec_ptp_read - read raw cycle counter (to be used by time counter)
203 * @cc: the cyclecounter structure
205 * this function reads the cyclecounter registers and is called by the
206 * cyclecounter structure used to construct a ns counter from the
207 * arbitrary fixed point registers
209 static u64 fec_ptp_read(const struct cyclecounter *cc)
211 struct fec_enet_private *fep =
212 container_of(cc, struct fec_enet_private, cc);
215 tempval = readl(fep->hwp + FEC_ATIME_CTRL);
216 tempval |= FEC_T_CTRL_CAPTURE;
217 writel(tempval, fep->hwp + FEC_ATIME_CTRL);
219 if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
222 return readl(fep->hwp + FEC_ATIME);
226 * fec_ptp_start_cyclecounter - create the cycle counter from hw
227 * @ndev: network device
229 * this function initializes the timecounter and cyclecounter
230 * structures for use in generated a ns counter from the arbitrary
231 * fixed point cycles registers in the hardware.
233 void fec_ptp_start_cyclecounter(struct net_device *ndev)
235 struct fec_enet_private *fep = netdev_priv(ndev);
239 inc = 1000000000 / fep->cycle_speed;
241 /* grab the ptp lock */
242 spin_lock_irqsave(&fep->tmreg_lock, flags);
245 writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
247 /* use 31-bit timer counter */
248 writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
250 writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
251 fep->hwp + FEC_ATIME_CTRL);
253 memset(&fep->cc, 0, sizeof(fep->cc));
254 fep->cc.read = fec_ptp_read;
255 fep->cc.mask = CLOCKSOURCE_MASK(31);
257 fep->cc.mult = FEC_CC_MULT;
259 /* reset the ns time counter */
260 timecounter_init(&fep->tc, &fep->cc, 0);
262 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
266 * fec_ptp_adjfreq - adjust ptp cycle frequency
267 * @ptp: the ptp clock structure
268 * @ppb: parts per billion adjustment from base
270 * Adjust the frequency of the ptp cycle counter by the
271 * indicated ppb from the base frequency.
273 * Because ENET hardware frequency adjust is complex,
274 * using software method to do that.
276 static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
281 u32 corr_inc, corr_period;
285 struct fec_enet_private *fep =
286 container_of(ptp, struct fec_enet_private, ptp_caps);
296 /* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
297 * Try to find the corr_inc between 1 to fep->ptp_inc to
298 * meet adjustment requirement.
301 rhs = (u64)ppb * (u64)fep->ptp_inc;
302 for (i = 1; i <= fep->ptp_inc; i++) {
305 corr_period = div_u64(lhs, rhs);
310 /* Not found? Set it to high value - double speed
311 * correct in every clock step.
313 if (i > fep->ptp_inc) {
314 corr_inc = fep->ptp_inc;
319 corr_ns = fep->ptp_inc - corr_inc;
321 corr_ns = fep->ptp_inc + corr_inc;
323 spin_lock_irqsave(&fep->tmreg_lock, flags);
325 tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
326 tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
327 writel(tmp, fep->hwp + FEC_ATIME_INC);
328 corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
329 writel(corr_period, fep->hwp + FEC_ATIME_CORR);
330 /* dummy read to update the timer. */
331 timecounter_read(&fep->tc);
333 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
340 * @ptp: the ptp clock structure
341 * @delta: offset to adjust the cycle counter by
343 * adjust the timer by resetting the timecounter structure.
345 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
347 struct fec_enet_private *fep =
348 container_of(ptp, struct fec_enet_private, ptp_caps);
351 spin_lock_irqsave(&fep->tmreg_lock, flags);
352 timecounter_adjtime(&fep->tc, delta);
353 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
360 * @ptp: the ptp clock structure
361 * @ts: timespec structure to hold the current time value
363 * read the timecounter and return the correct value on ns,
364 * after converting it into a struct timespec.
366 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
368 struct fec_enet_private *fep =
369 container_of(ptp, struct fec_enet_private, ptp_caps);
373 spin_lock_irqsave(&fep->tmreg_lock, flags);
374 /* Check the ptp clock */
375 if (!fep->ptp_clk_on) {
376 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
379 ns = timecounter_read(&fep->tc);
380 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
382 *ts = ns_to_timespec64(ns);
389 * @ptp: the ptp clock structure
390 * @ts: the timespec containing the new time for the cycle counter
392 * reset the timecounter to use a new base value instead of the kernel
395 static int fec_ptp_settime(struct ptp_clock_info *ptp,
396 const struct timespec64 *ts)
398 struct fec_enet_private *fep =
399 container_of(ptp, struct fec_enet_private, ptp_caps);
405 spin_lock_irqsave(&fep->tmreg_lock, flags);
406 /* Check the ptp clock */
407 if (!fep->ptp_clk_on) {
408 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
412 ns = timespec64_to_ns(ts);
413 /* Get the timer value based on timestamp.
414 * Update the counter with the masked value.
416 counter = ns & fep->cc.mask;
418 writel(counter, fep->hwp + FEC_ATIME);
419 timecounter_init(&fep->tc, &fep->cc, ns);
420 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
426 * @ptp: the ptp clock structure
427 * @rq: the requested feature to change
428 * @on: whether to enable or disable the feature
431 static int fec_ptp_enable(struct ptp_clock_info *ptp,
432 struct ptp_clock_request *rq, int on)
434 struct fec_enet_private *fep =
435 container_of(ptp, struct fec_enet_private, ptp_caps);
438 if (rq->type == PTP_CLK_REQ_PPS) {
439 ret = fec_ptp_enable_pps(fep, on);
447 * fec_ptp_disable_hwts - disable hardware time stamping
448 * @ndev: pointer to net_device
450 void fec_ptp_disable_hwts(struct net_device *ndev)
452 struct fec_enet_private *fep = netdev_priv(ndev);
458 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
460 struct fec_enet_private *fep = netdev_priv(ndev);
462 struct hwtstamp_config config;
464 if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
467 switch (config.tx_type) {
468 case HWTSTAMP_TX_OFF:
478 switch (config.rx_filter) {
479 case HWTSTAMP_FILTER_NONE:
485 config.rx_filter = HWTSTAMP_FILTER_ALL;
489 return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
493 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
495 struct fec_enet_private *fep = netdev_priv(ndev);
496 struct hwtstamp_config config;
499 config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
500 config.rx_filter = (fep->hwts_rx_en ?
501 HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
503 return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
508 * fec_time_keep - call timecounter_read every second to avoid timer overrun
509 * because ENET just support 32bit counter, will timeout in 4s
511 static void fec_time_keep(struct work_struct *work)
513 struct delayed_work *dwork = to_delayed_work(work);
514 struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
517 spin_lock_irqsave(&fep->tmreg_lock, flags);
518 if (fep->ptp_clk_on) {
519 timecounter_read(&fep->tc);
521 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
523 schedule_delayed_work(&fep->time_keep, HZ);
526 /* This function checks the pps event and reloads the timer compare counter. */
527 static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
529 struct net_device *ndev = dev_id;
530 struct fec_enet_private *fep = netdev_priv(ndev);
532 u8 channel = fep->pps_channel;
533 struct ptp_clock_event event;
535 val = readl(fep->hwp + FEC_TCSR(channel));
536 if (val & FEC_T_TF_MASK) {
537 /* Write the next next compare(not the next according the spec)
538 * value to the register
540 writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
542 writel(val, fep->hwp + FEC_TCSR(channel));
543 } while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
545 /* Update the counter; */
546 fep->next_counter = (fep->next_counter + fep->reload_period) &
549 event.type = PTP_CLOCK_PPS;
550 ptp_clock_event(fep->ptp_clock, &event);
559 * @pdev: The FEC network adapter
560 * @irq_idx: the interrupt index
562 * This function performs the required steps for enabling ptp
563 * support. If ptp support has already been loaded it simply calls the
564 * cyclecounter init routine and exits.
567 void fec_ptp_init(struct platform_device *pdev, int irq_idx)
569 struct net_device *ndev = platform_get_drvdata(pdev);
570 struct fec_enet_private *fep = netdev_priv(ndev);
574 fep->ptp_caps.owner = THIS_MODULE;
575 strlcpy(fep->ptp_caps.name, "fec ptp", sizeof(fep->ptp_caps.name));
577 fep->ptp_caps.max_adj = 250000000;
578 fep->ptp_caps.n_alarm = 0;
579 fep->ptp_caps.n_ext_ts = 0;
580 fep->ptp_caps.n_per_out = 0;
581 fep->ptp_caps.n_pins = 0;
582 fep->ptp_caps.pps = 1;
583 fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
584 fep->ptp_caps.adjtime = fec_ptp_adjtime;
585 fep->ptp_caps.gettime64 = fec_ptp_gettime;
586 fep->ptp_caps.settime64 = fec_ptp_settime;
587 fep->ptp_caps.enable = fec_ptp_enable;
589 fep->cycle_speed = clk_get_rate(fep->clk_ptp);
590 if (!fep->cycle_speed) {
591 fep->cycle_speed = NSEC_PER_SEC;
592 dev_err(&fep->pdev->dev, "clk_ptp clock rate is zero\n");
594 fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
596 fec_ptp_start_cyclecounter(ndev);
598 INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
600 irq = platform_get_irq_byname_optional(pdev, "pps");
602 irq = platform_get_irq_optional(pdev, irq_idx);
603 /* Failure to get an irq is not fatal,
604 * only the PTP_CLOCK_PPS clock events should stop
607 ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
608 0, pdev->name, ndev);
610 dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
614 fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
615 if (IS_ERR(fep->ptp_clock)) {
616 fep->ptp_clock = NULL;
617 dev_err(&pdev->dev, "ptp_clock_register failed\n");
620 schedule_delayed_work(&fep->time_keep, HZ);
623 void fec_ptp_stop(struct platform_device *pdev)
625 struct net_device *ndev = platform_get_drvdata(pdev);
626 struct fec_enet_private *fep = netdev_priv(ndev);
629 fec_ptp_enable_pps(fep, 0);
631 cancel_delayed_work_sync(&fep->time_keep);
633 ptp_clock_unregister(fep->ptp_clock);
636 void fec_ptp_save_state(struct fec_enet_private *fep)
640 fec_ptp_gettime(&fep->ptp_caps, &fep->ptp_saved_state.ts_phc);
641 fep->ptp_saved_state.ns_sys = ktime_get_ns();
643 fep->ptp_saved_state.at_corr = readl(fep->hwp + FEC_ATIME_CORR);
644 atime_inc_corr = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_CORR_MASK;
645 fep->ptp_saved_state.at_inc_corr = (u8)(atime_inc_corr >> FEC_T_INC_CORR_OFFSET);
648 int fec_ptp_restore_state(struct fec_enet_private *fep)
650 u32 atime_inc = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
653 writel(fep->ptp_saved_state.at_corr, fep->hwp + FEC_ATIME_CORR);
654 atime_inc |= ((u32)fep->ptp_saved_state.at_inc_corr) << FEC_T_INC_CORR_OFFSET;
655 writel(atime_inc, fep->hwp + FEC_ATIME_INC);
657 ns_sys = ktime_get_ns() - fep->ptp_saved_state.ns_sys;
658 timespec64_add_ns(&fep->ptp_saved_state.ts_phc, ns_sys);
659 return fec_ptp_settime(&fep->ptp_caps, &fep->ptp_saved_state.ts_phc);