1/*
2 * PTP 1588 clock using the eTSEC
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/device.h>
24#include <linux/hrtimer.h>
25#include <linux/interrupt.h>
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/of.h>
29#include <linux/of_platform.h>
30#include <linux/timex.h>
31#include <linux/io.h>
32
33#include <linux/ptp_clock_kernel.h>
34
35#include "gianfar.h"
36
37/*
38 * gianfar ptp registers
39 * Generated by regen.tcl on Thu May 13 01:38:57 PM CEST 2010
40 */
41struct gianfar_ptp_registers {
42	u32 tmr_ctrl;     /* Timer control register */
43	u32 tmr_tevent;   /* Timestamp event register */
44	u32 tmr_temask;   /* Timer event mask register */
45	u32 tmr_pevent;   /* Timestamp event register */
46	u32 tmr_pemask;   /* Timer event mask register */
47	u32 tmr_stat;     /* Timestamp status register */
48	u32 tmr_cnt_h;    /* Timer counter high register */
49	u32 tmr_cnt_l;    /* Timer counter low register */
50	u32 tmr_add;      /* Timer drift compensation addend register */
51	u32 tmr_acc;      /* Timer accumulator register */
52	u32 tmr_prsc;     /* Timer prescale */
53	u8  res1[4];
54	u32 tmroff_h;     /* Timer offset high */
55	u32 tmroff_l;     /* Timer offset low */
56	u8  res2[8];
57	u32 tmr_alarm1_h; /* Timer alarm 1 high register */
58	u32 tmr_alarm1_l; /* Timer alarm 1 high register */
59	u32 tmr_alarm2_h; /* Timer alarm 2 high register */
60	u32 tmr_alarm2_l; /* Timer alarm 2 high register */
61	u8  res3[48];
62	u32 tmr_fiper1;   /* Timer fixed period interval */
63	u32 tmr_fiper2;   /* Timer fixed period interval */
64	u32 tmr_fiper3;   /* Timer fixed period interval */
65	u8  res4[20];
66	u32 tmr_etts1_h;  /* Timestamp of general purpose external trigger */
67	u32 tmr_etts1_l;  /* Timestamp of general purpose external trigger */
68	u32 tmr_etts2_h;  /* Timestamp of general purpose external trigger */
69	u32 tmr_etts2_l;  /* Timestamp of general purpose external trigger */
70};
71
72/* Bit definitions for the TMR_CTRL register */
73#define ALM1P                 (1<<31) /* Alarm1 output polarity */
74#define ALM2P                 (1<<30) /* Alarm2 output polarity */
75#define FS                    (1<<28) /* FIPER start indication */
76#define PP1L                  (1<<27) /* Fiper1 pulse loopback mode enabled. */
77#define PP2L                  (1<<26) /* Fiper2 pulse loopback mode enabled. */
78#define TCLK_PERIOD_SHIFT     (16) /* 1588 timer reference clock period. */
79#define TCLK_PERIOD_MASK      (0x3ff)
80#define RTPE                  (1<<15) /* Record Tx Timestamp to PAL Enable. */
81#define FRD                   (1<<14) /* FIPER Realignment Disable */
82#define ESFDP                 (1<<11) /* External Tx/Rx SFD Polarity. */
83#define ESFDE                 (1<<10) /* External Tx/Rx SFD Enable. */
84#define ETEP2                 (1<<9) /* External trigger 2 edge polarity */
85#define ETEP1                 (1<<8) /* External trigger 1 edge polarity */
86#define COPH                  (1<<7) /* Generated clock output phase. */
87#define CIPH                  (1<<6) /* External oscillator input clock phase */
88#define TMSR                  (1<<5) /* Timer soft reset. */
89#define BYP                   (1<<3) /* Bypass drift compensated clock */
90#define TE                    (1<<2) /* 1588 timer enable. */
91#define CKSEL_SHIFT           (0)    /* 1588 Timer reference clock source */
92#define CKSEL_MASK            (0x3)
93
94/* Bit definitions for the TMR_TEVENT register */
95#define ETS2                  (1<<25) /* External trigger 2 timestamp sampled */
96#define ETS1                  (1<<24) /* External trigger 1 timestamp sampled */
97#define ALM2                  (1<<17) /* Current time = alarm time register 2 */
98#define ALM1                  (1<<16) /* Current time = alarm time register 1 */
99#define PP1                   (1<<7)  /* periodic pulse generated on FIPER1 */
100#define PP2                   (1<<6)  /* periodic pulse generated on FIPER2 */
101#define PP3                   (1<<5)  /* periodic pulse generated on FIPER3 */
102
103/* Bit definitions for the TMR_TEMASK register */
104#define ETS2EN                (1<<25) /* External trigger 2 timestamp enable */
105#define ETS1EN                (1<<24) /* External trigger 1 timestamp enable */
106#define ALM2EN                (1<<17) /* Timer ALM2 event enable */
107#define ALM1EN                (1<<16) /* Timer ALM1 event enable */
108#define PP1EN                 (1<<7) /* Periodic pulse event 1 enable */
109#define PP2EN                 (1<<6) /* Periodic pulse event 2 enable */
110
111/* Bit definitions for the TMR_PEVENT register */
112#define TXP2                  (1<<9) /* PTP transmitted timestamp im TXTS2 */
113#define TXP1                  (1<<8) /* PTP transmitted timestamp in TXTS1 */
114#define RXP                   (1<<0) /* PTP frame has been received */
115
116/* Bit definitions for the TMR_PEMASK register */
117#define TXP2EN                (1<<9) /* Transmit PTP packet event 2 enable */
118#define TXP1EN                (1<<8) /* Transmit PTP packet event 1 enable */
119#define RXPEN                 (1<<0) /* Receive PTP packet event enable */
120
121/* Bit definitions for the TMR_STAT register */
122#define STAT_VEC_SHIFT        (0) /* Timer general purpose status vector */
123#define STAT_VEC_MASK         (0x3f)
124
125/* Bit definitions for the TMR_PRSC register */
126#define PRSC_OCK_SHIFT        (0) /* Output clock division/prescale factor. */
127#define PRSC_OCK_MASK         (0xffff)
128
129
130#define DRIVER		"gianfar_ptp"
131#define DEFAULT_CKSEL	1
132#define N_EXT_TS	2
133#define REG_SIZE	sizeof(struct gianfar_ptp_registers)
134
135struct etsects {
136	struct gianfar_ptp_registers __iomem *regs;
137	spinlock_t lock; /* protects regs */
138	struct ptp_clock *clock;
139	struct ptp_clock_info caps;
140	struct resource *rsrc;
141	int irq;
142	u64 alarm_interval; /* for periodic alarm */
143	u64 alarm_value;
144	u32 tclk_period;  /* nanoseconds */
145	u32 tmr_prsc;
146	u32 tmr_add;
147	u32 cksel;
148	u32 tmr_fiper1;
149	u32 tmr_fiper2;
150};
151
152/*
153 * Register access functions
154 */
155
156/* Caller must hold etsects->lock. */
157static u64 tmr_cnt_read(struct etsects *etsects)
158{
159	u64 ns;
160	u32 lo, hi;
161
162	lo = gfar_read(&etsects->regs->tmr_cnt_l);
163	hi = gfar_read(&etsects->regs->tmr_cnt_h);
164	ns = ((u64) hi) << 32;
165	ns |= lo;
166	return ns;
167}
168
169/* Caller must hold etsects->lock. */
170static void tmr_cnt_write(struct etsects *etsects, u64 ns)
171{
172	u32 hi = ns >> 32;
173	u32 lo = ns & 0xffffffff;
174
175	gfar_write(&etsects->regs->tmr_cnt_l, lo);
176	gfar_write(&etsects->regs->tmr_cnt_h, hi);
177}
178
179/* Caller must hold etsects->lock. */
180static void set_alarm(struct etsects *etsects)
181{
182	u64 ns;
183	u32 lo, hi;
184
185	ns = tmr_cnt_read(etsects) + 1500000000ULL;
186	ns = div_u64(ns, 1000000000UL) * 1000000000ULL;
187	ns -= etsects->tclk_period;
188	hi = ns >> 32;
189	lo = ns & 0xffffffff;
190	gfar_write(&etsects->regs->tmr_alarm1_l, lo);
191	gfar_write(&etsects->regs->tmr_alarm1_h, hi);
192}
193
194/* Caller must hold etsects->lock. */
195static void set_fipers(struct etsects *etsects)
196{
197	set_alarm(etsects);
198	gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
199	gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
200}
201
202/*
203 * Interrupt service routine
204 */
205
206static irqreturn_t isr(int irq, void *priv)
207{
208	struct etsects *etsects = priv;
209	struct ptp_clock_event event;
210	u64 ns;
211	u32 ack = 0, lo, hi, mask, val;
212
213	val = gfar_read(&etsects->regs->tmr_tevent);
214
215	if (val & ETS1) {
216		ack |= ETS1;
217		hi = gfar_read(&etsects->regs->tmr_etts1_h);
218		lo = gfar_read(&etsects->regs->tmr_etts1_l);
219		event.type = PTP_CLOCK_EXTTS;
220		event.index = 0;
221		event.timestamp = ((u64) hi) << 32;
222		event.timestamp |= lo;
223		ptp_clock_event(etsects->clock, &event);
224	}
225
226	if (val & ETS2) {
227		ack |= ETS2;
228		hi = gfar_read(&etsects->regs->tmr_etts2_h);
229		lo = gfar_read(&etsects->regs->tmr_etts2_l);
230		event.type = PTP_CLOCK_EXTTS;
231		event.index = 1;
232		event.timestamp = ((u64) hi) << 32;
233		event.timestamp |= lo;
234		ptp_clock_event(etsects->clock, &event);
235	}
236
237	if (val & ALM2) {
238		ack |= ALM2;
239		if (etsects->alarm_value) {
240			event.type = PTP_CLOCK_ALARM;
241			event.index = 0;
242			event.timestamp = etsects->alarm_value;
243			ptp_clock_event(etsects->clock, &event);
244		}
245		if (etsects->alarm_interval) {
246			ns = etsects->alarm_value + etsects->alarm_interval;
247			hi = ns >> 32;
248			lo = ns & 0xffffffff;
249			spin_lock(&etsects->lock);
250			gfar_write(&etsects->regs->tmr_alarm2_l, lo);
251			gfar_write(&etsects->regs->tmr_alarm2_h, hi);
252			spin_unlock(&etsects->lock);
253			etsects->alarm_value = ns;
254		} else {
255			gfar_write(&etsects->regs->tmr_tevent, ALM2);
256			spin_lock(&etsects->lock);
257			mask = gfar_read(&etsects->regs->tmr_temask);
258			mask &= ~ALM2EN;
259			gfar_write(&etsects->regs->tmr_temask, mask);
260			spin_unlock(&etsects->lock);
261			etsects->alarm_value = 0;
262			etsects->alarm_interval = 0;
263		}
264	}
265
266	if (val & PP1) {
267		ack |= PP1;
268		event.type = PTP_CLOCK_PPS;
269		ptp_clock_event(etsects->clock, &event);
270	}
271
272	if (ack) {
273		gfar_write(&etsects->regs->tmr_tevent, ack);
274		return IRQ_HANDLED;
275	} else
276		return IRQ_NONE;
277}
278
279/*
280 * PTP clock operations
281 */
282
283static int ptp_gianfar_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
284{
285	u64 adj;
286	u32 diff, tmr_add;
287	int neg_adj = 0;
288	struct etsects *etsects = container_of(ptp, struct etsects, caps);
289
290	if (ppb < 0) {
291		neg_adj = 1;
292		ppb = -ppb;
293	}
294	tmr_add = etsects->tmr_add;
295	adj = tmr_add;
296	adj *= ppb;
297	diff = div_u64(adj, 1000000000ULL);
298
299	tmr_add = neg_adj ? tmr_add - diff : tmr_add + diff;
300
301	gfar_write(&etsects->regs->tmr_add, tmr_add);
302
303	return 0;
304}
305
306static int ptp_gianfar_adjtime(struct ptp_clock_info *ptp, s64 delta)
307{
308	s64 now;
309	unsigned long flags;
310	struct etsects *etsects = container_of(ptp, struct etsects, caps);
311
312	spin_lock_irqsave(&etsects->lock, flags);
313
314	now = tmr_cnt_read(etsects);
315	now += delta;
316	tmr_cnt_write(etsects, now);
317
318	spin_unlock_irqrestore(&etsects->lock, flags);
319
320	set_fipers(etsects);
321
322	return 0;
323}
324
325static int ptp_gianfar_gettime(struct ptp_clock_info *ptp,
326			       struct timespec64 *ts)
327{
328	u64 ns;
329	unsigned long flags;
330	struct etsects *etsects = container_of(ptp, struct etsects, caps);
331
332	spin_lock_irqsave(&etsects->lock, flags);
333
334	ns = tmr_cnt_read(etsects);
335
336	spin_unlock_irqrestore(&etsects->lock, flags);
337
338	*ts = ns_to_timespec64(ns);
339
340	return 0;
341}
342
343static int ptp_gianfar_settime(struct ptp_clock_info *ptp,
344			       const struct timespec64 *ts)
345{
346	u64 ns;
347	unsigned long flags;
348	struct etsects *etsects = container_of(ptp, struct etsects, caps);
349
350	ns = timespec64_to_ns(ts);
351
352	spin_lock_irqsave(&etsects->lock, flags);
353
354	tmr_cnt_write(etsects, ns);
355	set_fipers(etsects);
356
357	spin_unlock_irqrestore(&etsects->lock, flags);
358
359	return 0;
360}
361
362static int ptp_gianfar_enable(struct ptp_clock_info *ptp,
363			      struct ptp_clock_request *rq, int on)
364{
365	struct etsects *etsects = container_of(ptp, struct etsects, caps);
366	unsigned long flags;
367	u32 bit, mask;
368
369	switch (rq->type) {
370	case PTP_CLK_REQ_EXTTS:
371		switch (rq->extts.index) {
372		case 0:
373			bit = ETS1EN;
374			break;
375		case 1:
376			bit = ETS2EN;
377			break;
378		default:
379			return -EINVAL;
380		}
381		spin_lock_irqsave(&etsects->lock, flags);
382		mask = gfar_read(&etsects->regs->tmr_temask);
383		if (on)
384			mask |= bit;
385		else
386			mask &= ~bit;
387		gfar_write(&etsects->regs->tmr_temask, mask);
388		spin_unlock_irqrestore(&etsects->lock, flags);
389		return 0;
390
391	case PTP_CLK_REQ_PPS:
392		spin_lock_irqsave(&etsects->lock, flags);
393		mask = gfar_read(&etsects->regs->tmr_temask);
394		if (on)
395			mask |= PP1EN;
396		else
397			mask &= ~PP1EN;
398		gfar_write(&etsects->regs->tmr_temask, mask);
399		spin_unlock_irqrestore(&etsects->lock, flags);
400		return 0;
401
402	default:
403		break;
404	}
405
406	return -EOPNOTSUPP;
407}
408
409static struct ptp_clock_info ptp_gianfar_caps = {
410	.owner		= THIS_MODULE,
411	.name		= "gianfar clock",
412	.max_adj	= 512000,
413	.n_alarm	= 0,
414	.n_ext_ts	= N_EXT_TS,
415	.n_per_out	= 0,
416	.n_pins		= 0,
417	.pps		= 1,
418	.adjfreq	= ptp_gianfar_adjfreq,
419	.adjtime	= ptp_gianfar_adjtime,
420	.gettime64	= ptp_gianfar_gettime,
421	.settime64	= ptp_gianfar_settime,
422	.enable		= ptp_gianfar_enable,
423};
424
425/* OF device tree */
426
427static int get_of_u32(struct device_node *node, char *str, u32 *val)
428{
429	int plen;
430	const u32 *prop = of_get_property(node, str, &plen);
431
432	if (!prop || plen != sizeof(*prop))
433		return -1;
434	*val = *prop;
435	return 0;
436}
437
438static int gianfar_ptp_probe(struct platform_device *dev)
439{
440	struct device_node *node = dev->dev.of_node;
441	struct etsects *etsects;
442	struct timespec64 now;
443	int err = -ENOMEM;
444	u32 tmr_ctrl;
445	unsigned long flags;
446
447	etsects = kzalloc(sizeof(*etsects), GFP_KERNEL);
448	if (!etsects)
449		goto no_memory;
450
451	err = -ENODEV;
452
453	etsects->caps = ptp_gianfar_caps;
454
455	if (get_of_u32(node, "fsl,cksel", &etsects->cksel))
456		etsects->cksel = DEFAULT_CKSEL;
457
458	if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) ||
459	    get_of_u32(node, "fsl,tmr-prsc", &etsects->tmr_prsc) ||
460	    get_of_u32(node, "fsl,tmr-add", &etsects->tmr_add) ||
461	    get_of_u32(node, "fsl,tmr-fiper1", &etsects->tmr_fiper1) ||
462	    get_of_u32(node, "fsl,tmr-fiper2", &etsects->tmr_fiper2) ||
463	    get_of_u32(node, "fsl,max-adj", &etsects->caps.max_adj)) {
464		pr_err("device tree node missing required elements\n");
465		goto no_node;
466	}
467
468	etsects->irq = platform_get_irq(dev, 0);
469
470	if (etsects->irq == NO_IRQ) {
471		pr_err("irq not in device tree\n");
472		goto no_node;
473	}
474	if (request_irq(etsects->irq, isr, 0, DRIVER, etsects)) {
475		pr_err("request_irq failed\n");
476		goto no_node;
477	}
478
479	etsects->rsrc = platform_get_resource(dev, IORESOURCE_MEM, 0);
480	if (!etsects->rsrc) {
481		pr_err("no resource\n");
482		goto no_resource;
483	}
484	if (request_resource(&iomem_resource, etsects->rsrc)) {
485		pr_err("resource busy\n");
486		goto no_resource;
487	}
488
489	spin_lock_init(&etsects->lock);
490
491	etsects->regs = ioremap(etsects->rsrc->start,
492				resource_size(etsects->rsrc));
493	if (!etsects->regs) {
494		pr_err("ioremap ptp registers failed\n");
495		goto no_ioremap;
496	}
497	getnstimeofday64(&now);
498	ptp_gianfar_settime(&etsects->caps, &now);
499
500	tmr_ctrl =
501	  (etsects->tclk_period & TCLK_PERIOD_MASK) << TCLK_PERIOD_SHIFT |
502	  (etsects->cksel & CKSEL_MASK) << CKSEL_SHIFT;
503
504	spin_lock_irqsave(&etsects->lock, flags);
505
506	gfar_write(&etsects->regs->tmr_ctrl,   tmr_ctrl);
507	gfar_write(&etsects->regs->tmr_add,    etsects->tmr_add);
508	gfar_write(&etsects->regs->tmr_prsc,   etsects->tmr_prsc);
509	gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
510	gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
511	set_alarm(etsects);
512	gfar_write(&etsects->regs->tmr_ctrl,   tmr_ctrl|FS|RTPE|TE|FRD);
513
514	spin_unlock_irqrestore(&etsects->lock, flags);
515
516	etsects->clock = ptp_clock_register(&etsects->caps, &dev->dev);
517	if (IS_ERR(etsects->clock)) {
518		err = PTR_ERR(etsects->clock);
519		goto no_clock;
520	}
521	gfar_phc_index = ptp_clock_index(etsects->clock);
522
523	platform_set_drvdata(dev, etsects);
524
525	return 0;
526
527no_clock:
528	iounmap(etsects->regs);
529no_ioremap:
530	release_resource(etsects->rsrc);
531no_resource:
532	free_irq(etsects->irq, etsects);
533no_node:
534	kfree(etsects);
535no_memory:
536	return err;
537}
538
539static int gianfar_ptp_remove(struct platform_device *dev)
540{
541	struct etsects *etsects = platform_get_drvdata(dev);
542
543	gfar_write(&etsects->regs->tmr_temask, 0);
544	gfar_write(&etsects->regs->tmr_ctrl,   0);
545
546	gfar_phc_index = -1;
547	ptp_clock_unregister(etsects->clock);
548	iounmap(etsects->regs);
549	release_resource(etsects->rsrc);
550	free_irq(etsects->irq, etsects);
551	kfree(etsects);
552
553	return 0;
554}
555
556static const struct of_device_id match_table[] = {
557	{ .compatible = "fsl,etsec-ptp" },
558	{},
559};
560
561static struct platform_driver gianfar_ptp_driver = {
562	.driver = {
563		.name		= "gianfar_ptp",
564		.of_match_table	= match_table,
565	},
566	.probe       = gianfar_ptp_probe,
567	.remove      = gianfar_ptp_remove,
568};
569
570module_platform_driver(gianfar_ptp_driver);
571
572MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
573MODULE_DESCRIPTION("PTP clock using the eTSEC");
574MODULE_LICENSE("GPL");
575