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;
106 if (!(fep->hwts_tx_en || fep->hwts_rx_en)) {
107 dev_err(&fep->pdev->dev, "No ptp stack is running\n");
111 if (fep->pps_enable == enable)
114 fep->pps_channel = DEFAULT_PPS_CHANNEL;
115 fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
117 spin_lock_irqsave(&fep->tmreg_lock, flags);
120 /* clear capture or output compare interrupt status if have.
122 writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
124 /* It is recommended to double check the TMODE field in the
125 * TCSR register to be cleared before the first compare counter
126 * is written into TCCR register. Just add a double check.
128 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
130 val &= ~(FEC_T_TMODE_MASK);
131 writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
132 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
133 } while (val & FEC_T_TMODE_MASK);
135 /* Dummy read counter to update the counter */
136 timecounter_read(&fep->tc);
137 /* We want to find the first compare event in the next
138 * second point. So we need to know what the ptp time
139 * is now and how many nanoseconds is ahead to get next second.
140 * The remaining nanosecond ahead before the next second would be
141 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
142 * to current timer would be next second.
144 tempval = fep->cc.read(&fep->cc);
145 /* Convert the ptp local counter to 1588 timestamp */
146 ns = timecounter_cyc2time(&fep->tc, tempval);
147 ts = ns_to_timespec64(ns);
149 /* The tempval is less than 3 seconds, and so val is less than
150 * 4 seconds. No overflow for 32bit calculation.
152 val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
154 /* Need to consider the situation that the current time is
155 * very close to the second point, which means NSEC_PER_SEC
156 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
157 * is still running when we calculate the first compare event, it is
158 * possible that the remaining nanoseonds run out before the compare
159 * counter is calculated and written into TCCR register. To avoid
160 * this possibility, we will set the compare event to be the next
161 * of next second. The current setting is 31-bit timer and wrap
162 * around over 2 seconds. So it is okay to set the next of next
163 * seond for the timer.
167 /* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
168 * ptp counter, which maybe cause 32-bit wrap. Since the
169 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
170 * We can ensure the wrap will not cause issue. If the offset
171 * is bigger than fep->cc.mask would be a error.
174 writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
176 /* Calculate the second the compare event timestamp */
177 fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
179 /* * Enable compare event when overflow */
180 val = readl(fep->hwp + FEC_ATIME_CTRL);
181 val |= FEC_T_CTRL_PINPER;
182 writel(val, fep->hwp + FEC_ATIME_CTRL);
184 /* Compare channel setting. */
185 val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
186 val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
187 val &= ~(1 << FEC_T_TDRE_OFFSET);
188 val &= ~(FEC_T_TMODE_MASK);
189 val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
190 writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
192 /* Write the second compare event timestamp and calculate
193 * the third timestamp. Refer the TCCR register detail in the spec.
195 writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
196 fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
198 writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
201 fep->pps_enable = enable;
202 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
208 * fec_ptp_read - read raw cycle counter (to be used by time counter)
209 * @cc: the cyclecounter structure
211 * this function reads the cyclecounter registers and is called by the
212 * cyclecounter structure used to construct a ns counter from the
213 * arbitrary fixed point registers
215 static u64 fec_ptp_read(const struct cyclecounter *cc)
217 struct fec_enet_private *fep =
218 container_of(cc, struct fec_enet_private, cc);
221 tempval = readl(fep->hwp + FEC_ATIME_CTRL);
222 tempval |= FEC_T_CTRL_CAPTURE;
223 writel(tempval, fep->hwp + FEC_ATIME_CTRL);
225 if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
228 return readl(fep->hwp + FEC_ATIME);
232 * fec_ptp_start_cyclecounter - create the cycle counter from hw
233 * @ndev: network device
235 * this function initializes the timecounter and cyclecounter
236 * structures for use in generated a ns counter from the arbitrary
237 * fixed point cycles registers in the hardware.
239 void fec_ptp_start_cyclecounter(struct net_device *ndev)
241 struct fec_enet_private *fep = netdev_priv(ndev);
245 inc = 1000000000 / fep->cycle_speed;
247 /* grab the ptp lock */
248 spin_lock_irqsave(&fep->tmreg_lock, flags);
251 writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
253 /* use 31-bit timer counter */
254 writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
256 writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
257 fep->hwp + FEC_ATIME_CTRL);
259 memset(&fep->cc, 0, sizeof(fep->cc));
260 fep->cc.read = fec_ptp_read;
261 fep->cc.mask = CLOCKSOURCE_MASK(31);
263 fep->cc.mult = FEC_CC_MULT;
265 /* reset the ns time counter */
266 timecounter_init(&fep->tc, &fep->cc, ktime_to_ns(ktime_get_real()));
268 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
272 * fec_ptp_adjfreq - adjust ptp cycle frequency
273 * @ptp: the ptp clock structure
274 * @ppb: parts per billion adjustment from base
276 * Adjust the frequency of the ptp cycle counter by the
277 * indicated ppb from the base frequency.
279 * Because ENET hardware frequency adjust is complex,
280 * using software method to do that.
282 static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
287 u32 corr_inc, corr_period;
291 struct fec_enet_private *fep =
292 container_of(ptp, struct fec_enet_private, ptp_caps);
302 /* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
303 * Try to find the corr_inc between 1 to fep->ptp_inc to
304 * meet adjustment requirement.
307 rhs = (u64)ppb * (u64)fep->ptp_inc;
308 for (i = 1; i <= fep->ptp_inc; i++) {
311 corr_period = div_u64(lhs, rhs);
316 /* Not found? Set it to high value - double speed
317 * correct in every clock step.
319 if (i > fep->ptp_inc) {
320 corr_inc = fep->ptp_inc;
325 corr_ns = fep->ptp_inc - corr_inc;
327 corr_ns = fep->ptp_inc + corr_inc;
329 spin_lock_irqsave(&fep->tmreg_lock, flags);
331 tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
332 tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
333 writel(tmp, fep->hwp + FEC_ATIME_INC);
334 corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
335 writel(corr_period, fep->hwp + FEC_ATIME_CORR);
336 /* dummy read to update the timer. */
337 timecounter_read(&fep->tc);
339 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
346 * @ptp: the ptp clock structure
347 * @delta: offset to adjust the cycle counter by
349 * adjust the timer by resetting the timecounter structure.
351 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
353 struct fec_enet_private *fep =
354 container_of(ptp, struct fec_enet_private, ptp_caps);
357 spin_lock_irqsave(&fep->tmreg_lock, flags);
358 timecounter_adjtime(&fep->tc, delta);
359 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
366 * @ptp: the ptp clock structure
367 * @ts: timespec structure to hold the current time value
369 * read the timecounter and return the correct value on ns,
370 * after converting it into a struct timespec.
372 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
374 struct fec_enet_private *adapter =
375 container_of(ptp, struct fec_enet_private, ptp_caps);
379 mutex_lock(&adapter->ptp_clk_mutex);
380 /* Check the ptp clock */
381 if (!adapter->ptp_clk_on) {
382 mutex_unlock(&adapter->ptp_clk_mutex);
385 spin_lock_irqsave(&adapter->tmreg_lock, flags);
386 ns = timecounter_read(&adapter->tc);
387 spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
388 mutex_unlock(&adapter->ptp_clk_mutex);
390 *ts = ns_to_timespec64(ns);
397 * @ptp: the ptp clock structure
398 * @ts: the timespec containing the new time for the cycle counter
400 * reset the timecounter to use a new base value instead of the kernel
403 static int fec_ptp_settime(struct ptp_clock_info *ptp,
404 const struct timespec64 *ts)
406 struct fec_enet_private *fep =
407 container_of(ptp, struct fec_enet_private, ptp_caps);
413 mutex_lock(&fep->ptp_clk_mutex);
414 /* Check the ptp clock */
415 if (!fep->ptp_clk_on) {
416 mutex_unlock(&fep->ptp_clk_mutex);
420 ns = timespec64_to_ns(ts);
421 /* Get the timer value based on timestamp.
422 * Update the counter with the masked value.
424 counter = ns & fep->cc.mask;
426 spin_lock_irqsave(&fep->tmreg_lock, flags);
427 writel(counter, fep->hwp + FEC_ATIME);
428 timecounter_init(&fep->tc, &fep->cc, ns);
429 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
430 mutex_unlock(&fep->ptp_clk_mutex);
436 * @ptp: the ptp clock structure
437 * @rq: the requested feature to change
438 * @on: whether to enable or disable the feature
441 static int fec_ptp_enable(struct ptp_clock_info *ptp,
442 struct ptp_clock_request *rq, int on)
444 struct fec_enet_private *fep =
445 container_of(ptp, struct fec_enet_private, ptp_caps);
448 if (rq->type == PTP_CLK_REQ_PPS) {
449 ret = fec_ptp_enable_pps(fep, on);
456 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
458 struct fec_enet_private *fep = netdev_priv(ndev);
460 struct hwtstamp_config config;
462 if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
465 /* reserved for future extensions */
469 switch (config.tx_type) {
470 case HWTSTAMP_TX_OFF:
480 switch (config.rx_filter) {
481 case HWTSTAMP_FILTER_NONE:
484 config.rx_filter = HWTSTAMP_FILTER_NONE;
489 config.rx_filter = HWTSTAMP_FILTER_ALL;
493 return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
497 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
499 struct fec_enet_private *fep = netdev_priv(ndev);
500 struct hwtstamp_config config;
503 config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
504 config.rx_filter = (fep->hwts_rx_en ?
505 HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
507 return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
512 * fec_time_keep - call timecounter_read every second to avoid timer overrun
513 * because ENET just support 32bit counter, will timeout in 4s
515 static void fec_time_keep(struct work_struct *work)
517 struct delayed_work *dwork = to_delayed_work(work);
518 struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
522 mutex_lock(&fep->ptp_clk_mutex);
523 if (fep->ptp_clk_on) {
524 spin_lock_irqsave(&fep->tmreg_lock, flags);
525 ns = timecounter_read(&fep->tc);
526 spin_unlock_irqrestore(&fep->tmreg_lock, flags);
528 mutex_unlock(&fep->ptp_clk_mutex);
530 schedule_delayed_work(&fep->time_keep, HZ);
533 /* This function checks the pps event and reloads the timer compare counter. */
534 static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
536 struct net_device *ndev = dev_id;
537 struct fec_enet_private *fep = netdev_priv(ndev);
539 u8 channel = fep->pps_channel;
540 struct ptp_clock_event event;
542 val = readl(fep->hwp + FEC_TCSR(channel));
543 if (val & FEC_T_TF_MASK) {
544 /* Write the next next compare(not the next according the spec)
545 * value to the register
547 writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
549 writel(val, fep->hwp + FEC_TCSR(channel));
550 } while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
552 /* Update the counter; */
553 fep->next_counter = (fep->next_counter + fep->reload_period) &
556 event.type = PTP_CLOCK_PPS;
557 ptp_clock_event(fep->ptp_clock, &event);
566 * @ndev: The FEC network adapter
568 * This function performs the required steps for enabling ptp
569 * support. If ptp support has already been loaded it simply calls the
570 * cyclecounter init routine and exits.
573 void fec_ptp_init(struct platform_device *pdev, int irq_idx)
575 struct net_device *ndev = platform_get_drvdata(pdev);
576 struct fec_enet_private *fep = netdev_priv(ndev);
580 fep->ptp_caps.owner = THIS_MODULE;
581 snprintf(fep->ptp_caps.name, 16, "fec ptp");
583 fep->ptp_caps.max_adj = 250000000;
584 fep->ptp_caps.n_alarm = 0;
585 fep->ptp_caps.n_ext_ts = 0;
586 fep->ptp_caps.n_per_out = 0;
587 fep->ptp_caps.n_pins = 0;
588 fep->ptp_caps.pps = 1;
589 fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
590 fep->ptp_caps.adjtime = fec_ptp_adjtime;
591 fep->ptp_caps.gettime64 = fec_ptp_gettime;
592 fep->ptp_caps.settime64 = fec_ptp_settime;
593 fep->ptp_caps.enable = fec_ptp_enable;
595 fep->cycle_speed = clk_get_rate(fep->clk_ptp);
596 if (!fep->cycle_speed) {
597 fep->cycle_speed = NSEC_PER_SEC;
598 dev_err(&fep->pdev->dev, "clk_ptp clock rate is zero\n");
600 fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
602 spin_lock_init(&fep->tmreg_lock);
604 fec_ptp_start_cyclecounter(ndev);
606 INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
608 irq = platform_get_irq_byname(pdev, "pps");
610 irq = platform_get_irq(pdev, irq_idx);
611 /* Failure to get an irq is not fatal,
612 * only the PTP_CLOCK_PPS clock events should stop
615 ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
616 0, pdev->name, ndev);
618 dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
622 fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
623 if (IS_ERR(fep->ptp_clock)) {
624 fep->ptp_clock = NULL;
625 pr_err("ptp_clock_register failed\n");
628 schedule_delayed_work(&fep->time_keep, HZ);
631 void fec_ptp_stop(struct platform_device *pdev)
633 struct net_device *ndev = platform_get_drvdata(pdev);
634 struct fec_enet_private *fep = netdev_priv(ndev);
636 cancel_delayed_work_sync(&fep->time_keep);
638 ptp_clock_unregister(fep->ptp_clock);