xref: /linux/drivers/net/ethernet/ti/icssg/icss_iep.c (revision 643e2e259c2b25a2af0ae4c23c6e16586d9fd19c)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Texas Instruments ICSSG Industrial Ethernet Peripheral (IEP) Driver
4  *
5  * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com
6  *
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/timekeeping.h>
18 #include <linux/interrupt.h>
19 #include <linux/of_irq.h>
20 #include <linux/workqueue.h>
21 
22 #include "icss_iep.h"
23 
24 #define IEP_MAX_DEF_INC		0xf
25 #define IEP_MAX_COMPEN_INC		0xfff
26 #define IEP_MAX_COMPEN_COUNT	0xffffff
27 
28 #define IEP_GLOBAL_CFG_CNT_ENABLE	BIT(0)
29 #define IEP_GLOBAL_CFG_DEFAULT_INC_MASK		GENMASK(7, 4)
30 #define IEP_GLOBAL_CFG_DEFAULT_INC_SHIFT	4
31 #define IEP_GLOBAL_CFG_COMPEN_INC_MASK		GENMASK(19, 8)
32 #define IEP_GLOBAL_CFG_COMPEN_INC_SHIFT		8
33 
34 #define IEP_GLOBAL_STATUS_CNT_OVF	BIT(0)
35 
36 #define IEP_CMP_CFG_SHADOW_EN		BIT(17)
37 #define IEP_CMP_CFG_CMP0_RST_CNT_EN	BIT(0)
38 #define IEP_CMP_CFG_CMP_EN(cmp)		(GENMASK(16, 1) & (1 << ((cmp) + 1)))
39 
40 #define IEP_CMP_STATUS(cmp)		(1 << (cmp))
41 
42 #define IEP_SYNC_CTRL_SYNC_EN		BIT(0)
43 #define IEP_SYNC_CTRL_SYNC_N_EN(n)	(GENMASK(2, 1) & (BIT(1) << (n)))
44 
45 #define IEP_MIN_CMP	0
46 #define IEP_MAX_CMP	15
47 
48 #define ICSS_IEP_64BIT_COUNTER_SUPPORT		BIT(0)
49 #define ICSS_IEP_SLOW_COMPEN_REG_SUPPORT	BIT(1)
50 #define ICSS_IEP_SHADOW_MODE_SUPPORT		BIT(2)
51 
52 #define LATCH_INDEX(ts_index)			((ts_index) + 6)
53 #define IEP_CAP_CFG_CAPNR_1ST_EVENT_EN(n)	BIT(LATCH_INDEX(n))
54 #define IEP_CAP_CFG_CAP_ASYNC_EN(n)		BIT(LATCH_INDEX(n) + 10)
55 
56 /**
57  * icss_iep_get_count_hi() - Get the upper 32 bit IEP counter
58  * @iep: Pointer to structure representing IEP.
59  *
60  * Return: upper 32 bit IEP counter
61  */
62 int icss_iep_get_count_hi(struct icss_iep *iep)
63 {
64 	u32 val = 0;
65 
66 	if (iep && (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT))
67 		val = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
68 
69 	return val;
70 }
71 EXPORT_SYMBOL_GPL(icss_iep_get_count_hi);
72 
73 /**
74  * icss_iep_get_count_low() - Get the lower 32 bit IEP counter
75  * @iep: Pointer to structure representing IEP.
76  *
77  * Return: lower 32 bit IEP counter
78  */
79 int icss_iep_get_count_low(struct icss_iep *iep)
80 {
81 	u32 val = 0;
82 
83 	if (iep)
84 		val = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
85 
86 	return val;
87 }
88 EXPORT_SYMBOL_GPL(icss_iep_get_count_low);
89 
90 /**
91  * icss_iep_get_ptp_clock_idx() - Get PTP clock index using IEP driver
92  * @iep: Pointer to structure representing IEP.
93  *
94  * Return: PTP clock index, -1 if not registered
95  */
96 int icss_iep_get_ptp_clock_idx(struct icss_iep *iep)
97 {
98 	if (!iep || !iep->ptp_clock)
99 		return -1;
100 	return ptp_clock_index(iep->ptp_clock);
101 }
102 EXPORT_SYMBOL_GPL(icss_iep_get_ptp_clock_idx);
103 
104 static void icss_iep_set_counter(struct icss_iep *iep, u64 ns)
105 {
106 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
107 		writel(upper_32_bits(ns), iep->base +
108 		       iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
109 	writel(lower_32_bits(ns), iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
110 }
111 
112 static void icss_iep_update_to_next_boundary(struct icss_iep *iep, u64 start_ns);
113 
114 /**
115  * icss_iep_settime() - Set time of the PTP clock using IEP driver
116  * @iep: Pointer to structure representing IEP.
117  * @ns: Time to be set in nanoseconds
118  *
119  * This API uses writel() instead of regmap_write() for write operations as
120  * regmap_write() is too slow and this API is time sensitive.
121  */
122 static void icss_iep_settime(struct icss_iep *iep, u64 ns)
123 {
124 	if (iep->ops && iep->ops->settime) {
125 		iep->ops->settime(iep->clockops_data, ns);
126 		return;
127 	}
128 
129 	if (iep->pps_enabled || iep->perout_enabled)
130 		writel(0, iep->base + iep->plat_data->reg_offs[ICSS_IEP_SYNC_CTRL_REG]);
131 
132 	icss_iep_set_counter(iep, ns);
133 
134 	if (iep->pps_enabled || iep->perout_enabled) {
135 		icss_iep_update_to_next_boundary(iep, ns);
136 		writel(IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN,
137 		       iep->base + iep->plat_data->reg_offs[ICSS_IEP_SYNC_CTRL_REG]);
138 	}
139 }
140 
141 /**
142  * icss_iep_gettime() - Get time of the PTP clock using IEP driver
143  * @iep: Pointer to structure representing IEP.
144  * @sts: Pointer to structure representing PTP system timestamp.
145  *
146  * This API uses readl() instead of regmap_read() for read operations as
147  * regmap_read() is too slow and this API is time sensitive.
148  *
149  * Return: The current timestamp of the PTP clock using IEP driver
150  */
151 static u64 icss_iep_gettime(struct icss_iep *iep,
152 			    struct ptp_system_timestamp *sts)
153 {
154 	u32 ts_hi = 0, ts_lo;
155 	unsigned long flags;
156 
157 	if (iep->ops && iep->ops->gettime)
158 		return iep->ops->gettime(iep->clockops_data, sts);
159 
160 	/* use local_irq_x() to make it work for both RT/non-RT */
161 	local_irq_save(flags);
162 
163 	/* no need to play with hi-lo, hi is latched when lo is read */
164 	ptp_read_system_prets(sts);
165 	ts_lo = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
166 	ptp_read_system_postts(sts);
167 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
168 		ts_hi = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
169 
170 	local_irq_restore(flags);
171 
172 	return (u64)ts_lo | (u64)ts_hi << 32;
173 }
174 
175 static void icss_iep_enable(struct icss_iep *iep)
176 {
177 	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
178 			   IEP_GLOBAL_CFG_CNT_ENABLE,
179 			   IEP_GLOBAL_CFG_CNT_ENABLE);
180 }
181 
182 static void icss_iep_disable(struct icss_iep *iep)
183 {
184 	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
185 			   IEP_GLOBAL_CFG_CNT_ENABLE,
186 			   0);
187 }
188 
189 static void icss_iep_enable_shadow_mode(struct icss_iep *iep)
190 {
191 	u32 cycle_time;
192 	int cmp;
193 
194 	cycle_time = iep->cycle_time_ns - iep->def_inc;
195 
196 	icss_iep_disable(iep);
197 
198 	/* disable shadow mode */
199 	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
200 			   IEP_CMP_CFG_SHADOW_EN, 0);
201 
202 	/* enable shadow mode */
203 	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
204 			   IEP_CMP_CFG_SHADOW_EN, IEP_CMP_CFG_SHADOW_EN);
205 
206 	/* clear counters */
207 	icss_iep_set_counter(iep, 0);
208 
209 	/* clear overflow status */
210 	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_STATUS_REG,
211 			   IEP_GLOBAL_STATUS_CNT_OVF,
212 			   IEP_GLOBAL_STATUS_CNT_OVF);
213 
214 	/* clear compare status */
215 	for (cmp = IEP_MIN_CMP; cmp < IEP_MAX_CMP; cmp++) {
216 		regmap_update_bits(iep->map, ICSS_IEP_CMP_STAT_REG,
217 				   IEP_CMP_STATUS(cmp), IEP_CMP_STATUS(cmp));
218 
219 		regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
220 				   IEP_CMP_CFG_CMP_EN(cmp), 0);
221 	}
222 
223 	/* enable reset counter on CMP0 event */
224 	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
225 			   IEP_CMP_CFG_CMP0_RST_CNT_EN,
226 			   IEP_CMP_CFG_CMP0_RST_CNT_EN);
227 	/* enable compare */
228 	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
229 			   IEP_CMP_CFG_CMP_EN(0),
230 			   IEP_CMP_CFG_CMP_EN(0));
231 
232 	/* set CMP0 value to cycle time */
233 	regmap_write(iep->map, ICSS_IEP_CMP0_REG0, cycle_time);
234 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
235 		regmap_write(iep->map, ICSS_IEP_CMP0_REG1, cycle_time);
236 
237 	icss_iep_set_counter(iep, 0);
238 	icss_iep_enable(iep);
239 }
240 
241 static void icss_iep_set_default_inc(struct icss_iep *iep, u8 def_inc)
242 {
243 	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
244 			   IEP_GLOBAL_CFG_DEFAULT_INC_MASK,
245 			   def_inc << IEP_GLOBAL_CFG_DEFAULT_INC_SHIFT);
246 }
247 
248 static void icss_iep_set_compensation_inc(struct icss_iep *iep, u16 compen_inc)
249 {
250 	struct device *dev = regmap_get_device(iep->map);
251 
252 	if (compen_inc > IEP_MAX_COMPEN_INC) {
253 		dev_err(dev, "%s: too high compensation inc %d\n",
254 			__func__, compen_inc);
255 		compen_inc = IEP_MAX_COMPEN_INC;
256 	}
257 
258 	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
259 			   IEP_GLOBAL_CFG_COMPEN_INC_MASK,
260 			   compen_inc << IEP_GLOBAL_CFG_COMPEN_INC_SHIFT);
261 }
262 
263 static void icss_iep_set_compensation_count(struct icss_iep *iep,
264 					    u32 compen_count)
265 {
266 	struct device *dev = regmap_get_device(iep->map);
267 
268 	if (compen_count > IEP_MAX_COMPEN_COUNT) {
269 		dev_err(dev, "%s: too high compensation count %d\n",
270 			__func__, compen_count);
271 		compen_count = IEP_MAX_COMPEN_COUNT;
272 	}
273 
274 	regmap_write(iep->map, ICSS_IEP_COMPEN_REG, compen_count);
275 }
276 
277 static void icss_iep_set_slow_compensation_count(struct icss_iep *iep,
278 						 u32 compen_count)
279 {
280 	regmap_write(iep->map, ICSS_IEP_SLOW_COMPEN_REG, compen_count);
281 }
282 
283 /* PTP PHC operations */
284 static int icss_iep_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
285 {
286 	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
287 	s32 ppb = scaled_ppm_to_ppb(scaled_ppm);
288 	u32 cyc_count;
289 	u16 cmp_inc;
290 
291 	mutex_lock(&iep->ptp_clk_mutex);
292 
293 	/* ppb is amount of frequency we want to adjust in 1GHz (billion)
294 	 * e.g. 100ppb means we need to speed up clock by 100Hz
295 	 * i.e. at end of 1 second (1 billion ns) clock time, we should be
296 	 * counting 100 more ns.
297 	 * We use IEP slow compensation to achieve continuous freq. adjustment.
298 	 * There are 2 parts. Cycle time and adjustment per cycle.
299 	 * Simplest case would be 1 sec Cycle time. Then adjustment
300 	 * pre cycle would be (def_inc + ppb) value.
301 	 * Cycle time will have to be chosen based on how worse the ppb is.
302 	 * e.g. smaller the ppb, cycle time has to be large.
303 	 * The minimum adjustment we can do is +-1ns per cycle so let's
304 	 * reduce the cycle time to get 1ns per cycle adjustment.
305 	 *	1ppb = 1sec cycle time & 1ns adjust
306 	 *	1000ppb = 1/1000 cycle time & 1ns adjust per cycle
307 	 */
308 
309 	if (iep->cycle_time_ns)
310 		iep->slow_cmp_inc = iep->clk_tick_time;	/* 4ns adj per cycle */
311 	else
312 		iep->slow_cmp_inc = 1;	/* 1ns adjust per cycle */
313 
314 	if (ppb < 0) {
315 		iep->slow_cmp_inc = -iep->slow_cmp_inc;
316 		ppb = -ppb;
317 	}
318 
319 	cyc_count = NSEC_PER_SEC;		/* 1s cycle time @1GHz */
320 	cyc_count /= ppb;		/* cycle time per ppb */
321 
322 	/* slow_cmp_count is decremented every clock cycle, e.g. @250MHz */
323 	if (!iep->cycle_time_ns)
324 		cyc_count /= iep->clk_tick_time;
325 	iep->slow_cmp_count = cyc_count;
326 
327 	/* iep->clk_tick_time is def_inc */
328 	cmp_inc = iep->clk_tick_time + iep->slow_cmp_inc;
329 	icss_iep_set_compensation_inc(iep, cmp_inc);
330 	icss_iep_set_slow_compensation_count(iep, iep->slow_cmp_count);
331 
332 	mutex_unlock(&iep->ptp_clk_mutex);
333 
334 	return 0;
335 }
336 
337 static int icss_iep_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
338 {
339 	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
340 	s64 ns;
341 
342 	mutex_lock(&iep->ptp_clk_mutex);
343 	if (iep->ops && iep->ops->adjtime) {
344 		iep->ops->adjtime(iep->clockops_data, delta);
345 	} else {
346 		ns = icss_iep_gettime(iep, NULL);
347 		ns += delta;
348 		icss_iep_settime(iep, ns);
349 	}
350 	mutex_unlock(&iep->ptp_clk_mutex);
351 
352 	return 0;
353 }
354 
355 static int icss_iep_ptp_gettimeex(struct ptp_clock_info *ptp,
356 				  struct timespec64 *ts,
357 				  struct ptp_system_timestamp *sts)
358 {
359 	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
360 	u64 ns;
361 
362 	mutex_lock(&iep->ptp_clk_mutex);
363 	ns = icss_iep_gettime(iep, sts);
364 	*ts = ns_to_timespec64(ns);
365 	mutex_unlock(&iep->ptp_clk_mutex);
366 
367 	return 0;
368 }
369 
370 static int icss_iep_ptp_settime(struct ptp_clock_info *ptp,
371 				const struct timespec64 *ts)
372 {
373 	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
374 	u64 ns;
375 
376 	mutex_lock(&iep->ptp_clk_mutex);
377 	ns = timespec64_to_ns(ts);
378 	icss_iep_settime(iep, ns);
379 	mutex_unlock(&iep->ptp_clk_mutex);
380 
381 	return 0;
382 }
383 
384 static void icss_iep_update_to_next_boundary(struct icss_iep *iep, u64 start_ns)
385 {
386 	u64 ns, p_ns;
387 	u32 offset;
388 
389 	ns = icss_iep_gettime(iep, NULL);
390 	if (start_ns < ns)
391 		start_ns = ns;
392 	p_ns = iep->period;
393 	/* Round up to next period boundary */
394 	start_ns += p_ns - 1;
395 	offset = do_div(start_ns, p_ns);
396 	start_ns = start_ns * p_ns;
397 	/* If it is too close to update, shift to next boundary */
398 	if (p_ns - offset < 10)
399 		start_ns += p_ns;
400 
401 	regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(start_ns));
402 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
403 		regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(start_ns));
404 }
405 
406 static int icss_iep_perout_enable_hw(struct icss_iep *iep,
407 				     struct ptp_perout_request *req, int on)
408 {
409 	int ret;
410 	u64 cmp;
411 
412 	if (iep->ops && iep->ops->perout_enable) {
413 		ret = iep->ops->perout_enable(iep->clockops_data, req, on, &cmp);
414 		if (ret)
415 			return ret;
416 
417 		if (on) {
418 			/* Configure CMP */
419 			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(cmp));
420 			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
421 				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(cmp));
422 			/* Configure SYNC, 1ms pulse width */
423 			regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG, 1000000);
424 			regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
425 			regmap_write(iep->map, ICSS_IEP_SYNC_START_REG, 0);
426 			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0); /* one-shot mode */
427 			/* Enable CMP 1 */
428 			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
429 					   IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
430 		} else {
431 			/* Disable CMP 1 */
432 			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
433 					   IEP_CMP_CFG_CMP_EN(1), 0);
434 
435 			/* clear regs */
436 			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
437 			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
438 				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
439 		}
440 	} else {
441 		if (on) {
442 			u64 start_ns;
443 
444 			iep->period = ((u64)req->period.sec * NSEC_PER_SEC) +
445 				      req->period.nsec;
446 			start_ns = ((u64)req->period.sec * NSEC_PER_SEC)
447 				   + req->period.nsec;
448 			icss_iep_update_to_next_boundary(iep, start_ns);
449 
450 			/* Enable Sync in single shot mode  */
451 			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG,
452 				     IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN);
453 			/* Enable CMP 1 */
454 			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
455 					   IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
456 		} else {
457 			/* Disable CMP 1 */
458 			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
459 					   IEP_CMP_CFG_CMP_EN(1), 0);
460 
461 			/* clear CMP regs */
462 			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
463 			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
464 				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
465 
466 			/* Disable sync */
467 			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0);
468 		}
469 	}
470 
471 	return 0;
472 }
473 
474 static int icss_iep_perout_enable(struct icss_iep *iep,
475 				  struct ptp_perout_request *req, int on)
476 {
477 	int ret = 0;
478 
479 	mutex_lock(&iep->ptp_clk_mutex);
480 
481 	if (iep->pps_enabled) {
482 		ret = -EBUSY;
483 		goto exit;
484 	}
485 
486 	if (iep->perout_enabled == !!on)
487 		goto exit;
488 
489 	ret = icss_iep_perout_enable_hw(iep, req, on);
490 	if (!ret)
491 		iep->perout_enabled = !!on;
492 
493 exit:
494 	mutex_unlock(&iep->ptp_clk_mutex);
495 
496 	return ret;
497 }
498 
499 static void icss_iep_cap_cmp_work(struct work_struct *work)
500 {
501 	struct icss_iep *iep = container_of(work, struct icss_iep, work);
502 	const u32 *reg_offs = iep->plat_data->reg_offs;
503 	struct ptp_clock_event pevent;
504 	unsigned int val;
505 	u64 ns, ns_next;
506 
507 	mutex_lock(&iep->ptp_clk_mutex);
508 
509 	ns = readl(iep->base + reg_offs[ICSS_IEP_CMP1_REG0]);
510 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT) {
511 		val = readl(iep->base + reg_offs[ICSS_IEP_CMP1_REG1]);
512 		ns |= (u64)val << 32;
513 	}
514 	/* set next event */
515 	ns_next = ns + iep->period;
516 	writel(lower_32_bits(ns_next),
517 	       iep->base + reg_offs[ICSS_IEP_CMP1_REG0]);
518 	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
519 		writel(upper_32_bits(ns_next),
520 		       iep->base + reg_offs[ICSS_IEP_CMP1_REG1]);
521 
522 	pevent.pps_times.ts_real = ns_to_timespec64(ns);
523 	pevent.type = PTP_CLOCK_PPSUSR;
524 	pevent.index = 0;
525 	ptp_clock_event(iep->ptp_clock, &pevent);
526 	dev_dbg(iep->dev, "IEP:pps ts: %llu next:%llu:\n", ns, ns_next);
527 
528 	mutex_unlock(&iep->ptp_clk_mutex);
529 }
530 
531 static irqreturn_t icss_iep_cap_cmp_irq(int irq, void *dev_id)
532 {
533 	struct icss_iep *iep = (struct icss_iep *)dev_id;
534 	const u32 *reg_offs = iep->plat_data->reg_offs;
535 	unsigned int val;
536 
537 	val = readl(iep->base + reg_offs[ICSS_IEP_CMP_STAT_REG]);
538 	/* The driver only enables CMP1 */
539 	if (val & BIT(1)) {
540 		/* Clear the event */
541 		writel(BIT(1), iep->base + reg_offs[ICSS_IEP_CMP_STAT_REG]);
542 		if (iep->pps_enabled || iep->perout_enabled)
543 			schedule_work(&iep->work);
544 		return IRQ_HANDLED;
545 	}
546 
547 	return IRQ_NONE;
548 }
549 
550 static int icss_iep_pps_enable(struct icss_iep *iep, int on)
551 {
552 	struct ptp_clock_request rq;
553 	struct timespec64 ts;
554 	int ret = 0;
555 	u64 ns;
556 
557 	mutex_lock(&iep->ptp_clk_mutex);
558 
559 	if (iep->perout_enabled) {
560 		ret = -EBUSY;
561 		goto exit;
562 	}
563 
564 	if (iep->pps_enabled == !!on)
565 		goto exit;
566 
567 	rq.perout.index = 0;
568 	if (on) {
569 		ns = icss_iep_gettime(iep, NULL);
570 		ts = ns_to_timespec64(ns);
571 		rq.perout.period.sec = 1;
572 		rq.perout.period.nsec = 0;
573 		rq.perout.start.sec = ts.tv_sec + 2;
574 		rq.perout.start.nsec = 0;
575 		ret = icss_iep_perout_enable_hw(iep, &rq.perout, on);
576 	} else {
577 		ret = icss_iep_perout_enable_hw(iep, &rq.perout, on);
578 		if (iep->cap_cmp_irq)
579 			cancel_work_sync(&iep->work);
580 	}
581 
582 	if (!ret)
583 		iep->pps_enabled = !!on;
584 
585 exit:
586 	mutex_unlock(&iep->ptp_clk_mutex);
587 
588 	return ret;
589 }
590 
591 static int icss_iep_extts_enable(struct icss_iep *iep, u32 index, int on)
592 {
593 	u32 val, cap, ret = 0;
594 
595 	mutex_lock(&iep->ptp_clk_mutex);
596 
597 	if (iep->ops && iep->ops->extts_enable) {
598 		ret = iep->ops->extts_enable(iep->clockops_data, index, on);
599 		goto exit;
600 	}
601 
602 	if (((iep->latch_enable & BIT(index)) >> index) == on)
603 		goto exit;
604 
605 	regmap_read(iep->map, ICSS_IEP_CAPTURE_CFG_REG, &val);
606 	cap = IEP_CAP_CFG_CAP_ASYNC_EN(index) | IEP_CAP_CFG_CAPNR_1ST_EVENT_EN(index);
607 	if (on) {
608 		val |= cap;
609 		iep->latch_enable |= BIT(index);
610 	} else {
611 		val &= ~cap;
612 		iep->latch_enable &= ~BIT(index);
613 	}
614 	regmap_write(iep->map, ICSS_IEP_CAPTURE_CFG_REG, val);
615 
616 exit:
617 	mutex_unlock(&iep->ptp_clk_mutex);
618 
619 	return ret;
620 }
621 
622 static int icss_iep_ptp_enable(struct ptp_clock_info *ptp,
623 			       struct ptp_clock_request *rq, int on)
624 {
625 	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
626 
627 	switch (rq->type) {
628 	case PTP_CLK_REQ_PEROUT:
629 		return icss_iep_perout_enable(iep, &rq->perout, on);
630 	case PTP_CLK_REQ_PPS:
631 		return icss_iep_pps_enable(iep, on);
632 	case PTP_CLK_REQ_EXTTS:
633 		return icss_iep_extts_enable(iep, rq->extts.index, on);
634 	default:
635 		break;
636 	}
637 
638 	return -EOPNOTSUPP;
639 }
640 
641 static struct ptp_clock_info icss_iep_ptp_info = {
642 	.owner		= THIS_MODULE,
643 	.name		= "ICSS IEP timer",
644 	.max_adj	= 10000000,
645 	.adjfine	= icss_iep_ptp_adjfine,
646 	.adjtime	= icss_iep_ptp_adjtime,
647 	.gettimex64	= icss_iep_ptp_gettimeex,
648 	.settime64	= icss_iep_ptp_settime,
649 	.enable		= icss_iep_ptp_enable,
650 };
651 
652 struct icss_iep *icss_iep_get_idx(struct device_node *np, int idx)
653 {
654 	struct platform_device *pdev;
655 	struct device_node *iep_np;
656 	struct icss_iep *iep;
657 
658 	iep_np = of_parse_phandle(np, "ti,iep", idx);
659 	if (!iep_np || !of_device_is_available(iep_np))
660 		return ERR_PTR(-ENODEV);
661 
662 	pdev = of_find_device_by_node(iep_np);
663 	of_node_put(iep_np);
664 
665 	if (!pdev)
666 		/* probably IEP not yet probed */
667 		return ERR_PTR(-EPROBE_DEFER);
668 
669 	iep = platform_get_drvdata(pdev);
670 	if (!iep)
671 		return ERR_PTR(-EPROBE_DEFER);
672 
673 	device_lock(iep->dev);
674 	if (iep->client_np) {
675 		device_unlock(iep->dev);
676 		dev_err(iep->dev, "IEP is already acquired by %s",
677 			iep->client_np->name);
678 		return ERR_PTR(-EBUSY);
679 	}
680 	iep->client_np = np;
681 	device_unlock(iep->dev);
682 	get_device(iep->dev);
683 
684 	return iep;
685 }
686 EXPORT_SYMBOL_GPL(icss_iep_get_idx);
687 
688 struct icss_iep *icss_iep_get(struct device_node *np)
689 {
690 	return icss_iep_get_idx(np, 0);
691 }
692 EXPORT_SYMBOL_GPL(icss_iep_get);
693 
694 void icss_iep_put(struct icss_iep *iep)
695 {
696 	device_lock(iep->dev);
697 	iep->client_np = NULL;
698 	device_unlock(iep->dev);
699 	put_device(iep->dev);
700 }
701 EXPORT_SYMBOL_GPL(icss_iep_put);
702 
703 void icss_iep_init_fw(struct icss_iep *iep)
704 {
705 	/* start IEP for FW use in raw 64bit mode, no PTP support */
706 	iep->clk_tick_time = iep->def_inc;
707 	iep->cycle_time_ns = 0;
708 	iep->ops = NULL;
709 	iep->clockops_data = NULL;
710 	icss_iep_set_default_inc(iep, iep->def_inc);
711 	icss_iep_set_compensation_inc(iep, iep->def_inc);
712 	icss_iep_set_compensation_count(iep, 0);
713 	regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG, iep->refclk_freq / 10); /* 100 ms pulse */
714 	regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
715 	if (iep->plat_data->flags & ICSS_IEP_SLOW_COMPEN_REG_SUPPORT)
716 		icss_iep_set_slow_compensation_count(iep, 0);
717 
718 	icss_iep_enable(iep);
719 	icss_iep_settime(iep, 0);
720 }
721 EXPORT_SYMBOL_GPL(icss_iep_init_fw);
722 
723 void icss_iep_exit_fw(struct icss_iep *iep)
724 {
725 	icss_iep_disable(iep);
726 }
727 EXPORT_SYMBOL_GPL(icss_iep_exit_fw);
728 
729 int icss_iep_init(struct icss_iep *iep, const struct icss_iep_clockops *clkops,
730 		  void *clockops_data, u32 cycle_time_ns)
731 {
732 	int ret = 0;
733 
734 	iep->cycle_time_ns = cycle_time_ns;
735 	iep->clk_tick_time = iep->def_inc;
736 	iep->ops = clkops;
737 	iep->clockops_data = clockops_data;
738 	icss_iep_set_default_inc(iep, iep->def_inc);
739 	icss_iep_set_compensation_inc(iep, iep->def_inc);
740 	icss_iep_set_compensation_count(iep, 0);
741 	regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG, iep->refclk_freq / 10); /* 100 ms pulse */
742 	regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
743 	if (iep->plat_data->flags & ICSS_IEP_SLOW_COMPEN_REG_SUPPORT)
744 		icss_iep_set_slow_compensation_count(iep, 0);
745 
746 	if (!(iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT) ||
747 	    !(iep->plat_data->flags & ICSS_IEP_SLOW_COMPEN_REG_SUPPORT))
748 		goto skip_perout;
749 
750 	if (iep->ops && iep->ops->perout_enable) {
751 		iep->ptp_info.n_per_out = 1;
752 		iep->ptp_info.pps = 1;
753 	} else if (iep->cap_cmp_irq) {
754 		iep->ptp_info.pps = 1;
755 	}
756 
757 	if (iep->ops && iep->ops->extts_enable)
758 		iep->ptp_info.n_ext_ts = 2;
759 
760 skip_perout:
761 	if (cycle_time_ns)
762 		icss_iep_enable_shadow_mode(iep);
763 	else
764 		icss_iep_enable(iep);
765 	icss_iep_settime(iep, ktime_get_real_ns());
766 
767 	iep->ptp_clock = ptp_clock_register(&iep->ptp_info, iep->dev);
768 	if (IS_ERR(iep->ptp_clock)) {
769 		ret = PTR_ERR(iep->ptp_clock);
770 		iep->ptp_clock = NULL;
771 		dev_err(iep->dev, "Failed to register ptp clk %d\n", ret);
772 	}
773 
774 	return ret;
775 }
776 EXPORT_SYMBOL_GPL(icss_iep_init);
777 
778 int icss_iep_exit(struct icss_iep *iep)
779 {
780 	if (iep->ptp_clock) {
781 		ptp_clock_unregister(iep->ptp_clock);
782 		iep->ptp_clock = NULL;
783 	}
784 	icss_iep_disable(iep);
785 
786 	if (iep->pps_enabled)
787 		icss_iep_pps_enable(iep, false);
788 	else if (iep->perout_enabled)
789 		icss_iep_perout_enable(iep, NULL, false);
790 
791 	return 0;
792 }
793 EXPORT_SYMBOL_GPL(icss_iep_exit);
794 
795 static int icss_iep_probe(struct platform_device *pdev)
796 {
797 	struct device *dev = &pdev->dev;
798 	struct icss_iep *iep;
799 	struct clk *iep_clk;
800 	int ret, irq;
801 
802 	iep = devm_kzalloc(dev, sizeof(*iep), GFP_KERNEL);
803 	if (!iep)
804 		return -ENOMEM;
805 
806 	iep->dev = dev;
807 	iep->base = devm_platform_ioremap_resource(pdev, 0);
808 	if (IS_ERR(iep->base))
809 		return -ENODEV;
810 
811 	irq = platform_get_irq_byname_optional(pdev, "iep_cap_cmp");
812 	if (irq == -EPROBE_DEFER)
813 		return irq;
814 
815 	if (irq > 0) {
816 		ret = devm_request_irq(dev, irq, icss_iep_cap_cmp_irq,
817 				       IRQF_TRIGGER_HIGH, "iep_cap_cmp", iep);
818 		if (ret) {
819 			dev_info(iep->dev, "cap_cmp irq request failed: %x\n",
820 				 ret);
821 		} else {
822 			iep->cap_cmp_irq = irq;
823 			INIT_WORK(&iep->work, icss_iep_cap_cmp_work);
824 		}
825 	}
826 
827 	iep_clk = devm_clk_get(dev, NULL);
828 	if (IS_ERR(iep_clk))
829 		return PTR_ERR(iep_clk);
830 
831 	iep->refclk_freq = clk_get_rate(iep_clk);
832 
833 	iep->def_inc = NSEC_PER_SEC / iep->refclk_freq;	/* ns per clock tick */
834 	if (iep->def_inc > IEP_MAX_DEF_INC) {
835 		dev_err(dev, "Failed to set def_inc %d.  IEP_clock is too slow to be supported\n",
836 			iep->def_inc);
837 		return -EINVAL;
838 	}
839 
840 	iep->plat_data = device_get_match_data(dev);
841 	if (!iep->plat_data)
842 		return -EINVAL;
843 
844 	iep->map = devm_regmap_init(dev, NULL, iep, iep->plat_data->config);
845 	if (IS_ERR(iep->map)) {
846 		dev_err(dev, "Failed to create regmap for IEP %ld\n",
847 			PTR_ERR(iep->map));
848 		return PTR_ERR(iep->map);
849 	}
850 
851 	iep->ptp_info = icss_iep_ptp_info;
852 	mutex_init(&iep->ptp_clk_mutex);
853 	dev_set_drvdata(dev, iep);
854 	icss_iep_disable(iep);
855 
856 	return 0;
857 }
858 
859 static bool am654_icss_iep_valid_reg(struct device *dev, unsigned int reg)
860 {
861 	switch (reg) {
862 	case ICSS_IEP_GLOBAL_CFG_REG ... ICSS_IEP_SYNC_START_REG:
863 		return true;
864 	default:
865 		return false;
866 	}
867 
868 	return false;
869 }
870 
871 static int icss_iep_regmap_write(void *context, unsigned int reg,
872 				 unsigned int val)
873 {
874 	struct icss_iep *iep = context;
875 
876 	writel(val, iep->base + iep->plat_data->reg_offs[reg]);
877 
878 	return 0;
879 }
880 
881 static int icss_iep_regmap_read(void *context, unsigned int reg,
882 				unsigned int *val)
883 {
884 	struct icss_iep *iep = context;
885 
886 	*val = readl(iep->base + iep->plat_data->reg_offs[reg]);
887 
888 	return 0;
889 }
890 
891 static const struct regmap_config am654_icss_iep_regmap_config = {
892 	.name = "icss iep",
893 	.reg_stride = 1,
894 	.reg_write = icss_iep_regmap_write,
895 	.reg_read = icss_iep_regmap_read,
896 	.writeable_reg = am654_icss_iep_valid_reg,
897 	.readable_reg = am654_icss_iep_valid_reg,
898 	.fast_io = 1,
899 };
900 
901 static const struct icss_iep_plat_data am654_icss_iep_plat_data = {
902 	.flags = ICSS_IEP_64BIT_COUNTER_SUPPORT |
903 		 ICSS_IEP_SLOW_COMPEN_REG_SUPPORT |
904 		 ICSS_IEP_SHADOW_MODE_SUPPORT,
905 	.reg_offs = {
906 		[ICSS_IEP_GLOBAL_CFG_REG] = 0x00,
907 		[ICSS_IEP_COMPEN_REG] = 0x08,
908 		[ICSS_IEP_SLOW_COMPEN_REG] = 0x0C,
909 		[ICSS_IEP_COUNT_REG0] = 0x10,
910 		[ICSS_IEP_COUNT_REG1] = 0x14,
911 		[ICSS_IEP_CAPTURE_CFG_REG] = 0x18,
912 		[ICSS_IEP_CAPTURE_STAT_REG] = 0x1c,
913 
914 		[ICSS_IEP_CAP6_RISE_REG0] = 0x50,
915 		[ICSS_IEP_CAP6_RISE_REG1] = 0x54,
916 
917 		[ICSS_IEP_CAP7_RISE_REG0] = 0x60,
918 		[ICSS_IEP_CAP7_RISE_REG1] = 0x64,
919 
920 		[ICSS_IEP_CMP_CFG_REG] = 0x70,
921 		[ICSS_IEP_CMP_STAT_REG] = 0x74,
922 		[ICSS_IEP_CMP0_REG0] = 0x78,
923 		[ICSS_IEP_CMP0_REG1] = 0x7c,
924 		[ICSS_IEP_CMP1_REG0] = 0x80,
925 		[ICSS_IEP_CMP1_REG1] = 0x84,
926 
927 		[ICSS_IEP_CMP8_REG0] = 0xc0,
928 		[ICSS_IEP_CMP8_REG1] = 0xc4,
929 		[ICSS_IEP_SYNC_CTRL_REG] = 0x180,
930 		[ICSS_IEP_SYNC0_STAT_REG] = 0x188,
931 		[ICSS_IEP_SYNC1_STAT_REG] = 0x18c,
932 		[ICSS_IEP_SYNC_PWIDTH_REG] = 0x190,
933 		[ICSS_IEP_SYNC0_PERIOD_REG] = 0x194,
934 		[ICSS_IEP_SYNC1_DELAY_REG] = 0x198,
935 		[ICSS_IEP_SYNC_START_REG] = 0x19c,
936 	},
937 	.config = &am654_icss_iep_regmap_config,
938 };
939 
940 static const struct of_device_id icss_iep_of_match[] = {
941 	{
942 		.compatible = "ti,am654-icss-iep",
943 		.data = &am654_icss_iep_plat_data,
944 	},
945 	{},
946 };
947 MODULE_DEVICE_TABLE(of, icss_iep_of_match);
948 
949 static struct platform_driver icss_iep_driver = {
950 	.driver = {
951 		.name = "icss-iep",
952 		.of_match_table = icss_iep_of_match,
953 	},
954 	.probe = icss_iep_probe,
955 };
956 module_platform_driver(icss_iep_driver);
957 
958 MODULE_LICENSE("GPL");
959 MODULE_DESCRIPTION("TI ICSS IEP driver");
960 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
961 MODULE_AUTHOR("Md Danish Anwar <danishanwar@ti.com>");
962