1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * PRU-ICSS INTC IRQChip driver for various TI SoCs
4 *
5 * Copyright (C) 2016-2020 Texas Instruments Incorporated - http://www.ti.com/
6 *
7 * Author(s):
8 *	Andrew F. Davis <afd@ti.com>
9 *	Suman Anna <s-anna@ti.com>
10 *	Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> for Texas Instruments
11 *
12 * Copyright (C) 2019 David Lechner <david@lechnology.com>
13 */
14
15#include <linux/interrupt.h>
16#include <linux/irq.h>
17#include <linux/irqchip/chained_irq.h>
18#include <linux/irqdomain.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22
23/*
24 * Number of host interrupts reaching the main MPU sub-system. Note that this
25 * is not the same as the total number of host interrupts supported by the PRUSS
26 * INTC instance
27 */
28#define MAX_NUM_HOST_IRQS	8
29
30/* minimum starting host interrupt number for MPU */
31#define FIRST_PRU_HOST_INT	2
32
33/* PRU_ICSS_INTC registers */
34#define PRU_INTC_REVID		0x0000
35#define PRU_INTC_CR		0x0004
36#define PRU_INTC_GER		0x0010
37#define PRU_INTC_GNLR		0x001c
38#define PRU_INTC_SISR		0x0020
39#define PRU_INTC_SICR		0x0024
40#define PRU_INTC_EISR		0x0028
41#define PRU_INTC_EICR		0x002c
42#define PRU_INTC_HIEISR		0x0034
43#define PRU_INTC_HIDISR		0x0038
44#define PRU_INTC_GPIR		0x0080
45#define PRU_INTC_SRSR(x)	(0x0200 + (x) * 4)
46#define PRU_INTC_SECR(x)	(0x0280 + (x) * 4)
47#define PRU_INTC_ESR(x)		(0x0300 + (x) * 4)
48#define PRU_INTC_ECR(x)		(0x0380 + (x) * 4)
49#define PRU_INTC_CMR(x)		(0x0400 + (x) * 4)
50#define PRU_INTC_HMR(x)		(0x0800 + (x) * 4)
51#define PRU_INTC_HIPIR(x)	(0x0900 + (x) * 4)
52#define PRU_INTC_SIPR(x)	(0x0d00 + (x) * 4)
53#define PRU_INTC_SITR(x)	(0x0d80 + (x) * 4)
54#define PRU_INTC_HINLR(x)	(0x1100 + (x) * 4)
55#define PRU_INTC_HIER		0x1500
56
57/* CMR register bit-field macros */
58#define CMR_EVT_MAP_MASK	0xf
59#define CMR_EVT_MAP_BITS	8
60#define CMR_EVT_PER_REG		4
61
62/* HMR register bit-field macros */
63#define HMR_CH_MAP_MASK		0xf
64#define HMR_CH_MAP_BITS		8
65#define HMR_CH_PER_REG		4
66
67/* HIPIR register bit-fields */
68#define INTC_HIPIR_NONE_HINT	0x80000000
69
70#define MAX_PRU_SYS_EVENTS 160
71#define MAX_PRU_CHANNELS 20
72
73/**
74 * struct pruss_intc_map_record - keeps track of actual mapping state
75 * @value: The currently mapped value (channel or host)
76 * @ref_count: Keeps track of number of current users of this resource
77 */
78struct pruss_intc_map_record {
79	u8 value;
80	u8 ref_count;
81};
82
83/**
84 * struct pruss_intc_match_data - match data to handle SoC variations
85 * @num_system_events: number of input system events handled by the PRUSS INTC
86 * @num_host_events: number of host events (which is equal to number of
87 *		     channels) supported by the PRUSS INTC
88 */
89struct pruss_intc_match_data {
90	u8 num_system_events;
91	u8 num_host_events;
92};
93
94/**
95 * struct pruss_intc - PRUSS interrupt controller structure
96 * @event_channel: current state of system event to channel mappings
97 * @channel_host: current state of channel to host mappings
98 * @irqs: kernel irq numbers corresponding to PRUSS host interrupts
99 * @base: base virtual address of INTC register space
100 * @domain: irq domain for this interrupt controller
101 * @soc_config: cached PRUSS INTC IP configuration data
102 * @dev: PRUSS INTC device pointer
103 * @lock: mutex to serialize interrupts mapping
104 */
105struct pruss_intc {
106	struct pruss_intc_map_record event_channel[MAX_PRU_SYS_EVENTS];
107	struct pruss_intc_map_record channel_host[MAX_PRU_CHANNELS];
108	unsigned int irqs[MAX_NUM_HOST_IRQS];
109	void __iomem *base;
110	struct irq_domain *domain;
111	const struct pruss_intc_match_data *soc_config;
112	struct device *dev;
113	struct mutex lock; /* PRUSS INTC lock */
114};
115
116/**
117 * struct pruss_host_irq_data - PRUSS host irq data structure
118 * @intc: PRUSS interrupt controller pointer
119 * @host_irq: host irq number
120 */
121struct pruss_host_irq_data {
122	struct pruss_intc *intc;
123	u8 host_irq;
124};
125
126static inline u32 pruss_intc_read_reg(struct pruss_intc *intc, unsigned int reg)
127{
128	return readl_relaxed(intc->base + reg);
129}
130
131static inline void pruss_intc_write_reg(struct pruss_intc *intc,
132					unsigned int reg, u32 val)
133{
134	writel_relaxed(val, intc->base + reg);
135}
136
137static void pruss_intc_update_cmr(struct pruss_intc *intc, unsigned int evt,
138				  u8 ch)
139{
140	u32 idx, offset, val;
141
142	idx = evt / CMR_EVT_PER_REG;
143	offset = (evt % CMR_EVT_PER_REG) * CMR_EVT_MAP_BITS;
144
145	val = pruss_intc_read_reg(intc, PRU_INTC_CMR(idx));
146	val &= ~(CMR_EVT_MAP_MASK << offset);
147	val |= ch << offset;
148	pruss_intc_write_reg(intc, PRU_INTC_CMR(idx), val);
149
150	dev_dbg(intc->dev, "SYSEV%u -> CH%d (CMR%d 0x%08x)\n", evt, ch,
151		idx, pruss_intc_read_reg(intc, PRU_INTC_CMR(idx)));
152}
153
154static void pruss_intc_update_hmr(struct pruss_intc *intc, u8 ch, u8 host)
155{
156	u32 idx, offset, val;
157
158	idx = ch / HMR_CH_PER_REG;
159	offset = (ch % HMR_CH_PER_REG) * HMR_CH_MAP_BITS;
160
161	val = pruss_intc_read_reg(intc, PRU_INTC_HMR(idx));
162	val &= ~(HMR_CH_MAP_MASK << offset);
163	val |= host << offset;
164	pruss_intc_write_reg(intc, PRU_INTC_HMR(idx), val);
165
166	dev_dbg(intc->dev, "CH%d -> HOST%d (HMR%d 0x%08x)\n", ch, host, idx,
167		pruss_intc_read_reg(intc, PRU_INTC_HMR(idx)));
168}
169
170/**
171 * pruss_intc_map() - configure the PRUSS INTC
172 * @intc: PRUSS interrupt controller pointer
173 * @hwirq: the system event number
174 *
175 * Configures the PRUSS INTC with the provided configuration from the one parsed
176 * in the xlate function.
177 */
178static void pruss_intc_map(struct pruss_intc *intc, unsigned long hwirq)
179{
180	struct device *dev = intc->dev;
181	u8 ch, host, reg_idx;
182	u32 val;
183
184	mutex_lock(&intc->lock);
185
186	intc->event_channel[hwirq].ref_count++;
187
188	ch = intc->event_channel[hwirq].value;
189	host = intc->channel_host[ch].value;
190
191	pruss_intc_update_cmr(intc, hwirq, ch);
192
193	reg_idx = hwirq / 32;
194	val = BIT(hwirq  % 32);
195
196	/* clear and enable system event */
197	pruss_intc_write_reg(intc, PRU_INTC_ESR(reg_idx), val);
198	pruss_intc_write_reg(intc, PRU_INTC_SECR(reg_idx), val);
199
200	if (++intc->channel_host[ch].ref_count == 1) {
201		pruss_intc_update_hmr(intc, ch, host);
202
203		/* enable host interrupts */
204		pruss_intc_write_reg(intc, PRU_INTC_HIEISR, host);
205	}
206
207	dev_dbg(dev, "mapped system_event = %lu channel = %d host = %d",
208		hwirq, ch, host);
209
210	mutex_unlock(&intc->lock);
211}
212
213/**
214 * pruss_intc_unmap() - unconfigure the PRUSS INTC
215 * @intc: PRUSS interrupt controller pointer
216 * @hwirq: the system event number
217 *
218 * Undo whatever was done in pruss_intc_map() for a PRU core.
219 * Mappings are reference counted, so resources are only disabled when there
220 * are no longer any users.
221 */
222static void pruss_intc_unmap(struct pruss_intc *intc, unsigned long hwirq)
223{
224	u8 ch, host, reg_idx;
225	u32 val;
226
227	mutex_lock(&intc->lock);
228
229	ch = intc->event_channel[hwirq].value;
230	host = intc->channel_host[ch].value;
231
232	if (--intc->channel_host[ch].ref_count == 0) {
233		/* disable host interrupts */
234		pruss_intc_write_reg(intc, PRU_INTC_HIDISR, host);
235
236		/* clear the map using reset value 0 */
237		pruss_intc_update_hmr(intc, ch, 0);
238	}
239
240	intc->event_channel[hwirq].ref_count--;
241	reg_idx = hwirq / 32;
242	val = BIT(hwirq  % 32);
243
244	/* disable system events */
245	pruss_intc_write_reg(intc, PRU_INTC_ECR(reg_idx), val);
246	/* clear any pending status */
247	pruss_intc_write_reg(intc, PRU_INTC_SECR(reg_idx), val);
248
249	/* clear the map using reset value 0 */
250	pruss_intc_update_cmr(intc, hwirq, 0);
251
252	dev_dbg(intc->dev, "unmapped system_event = %lu channel = %d host = %d\n",
253		hwirq, ch, host);
254
255	mutex_unlock(&intc->lock);
256}
257
258static void pruss_intc_init(struct pruss_intc *intc)
259{
260	const struct pruss_intc_match_data *soc_config = intc->soc_config;
261	int num_chnl_map_regs, num_host_intr_regs, num_event_type_regs, i;
262
263	num_chnl_map_regs = DIV_ROUND_UP(soc_config->num_system_events,
264					 CMR_EVT_PER_REG);
265	num_host_intr_regs = DIV_ROUND_UP(soc_config->num_host_events,
266					  HMR_CH_PER_REG);
267	num_event_type_regs = DIV_ROUND_UP(soc_config->num_system_events, 32);
268
269	/*
270	 * configure polarity (SIPR register) to active high and
271	 * type (SITR register) to level interrupt for all system events
272	 */
273	for (i = 0; i < num_event_type_regs; i++) {
274		pruss_intc_write_reg(intc, PRU_INTC_SIPR(i), 0xffffffff);
275		pruss_intc_write_reg(intc, PRU_INTC_SITR(i), 0);
276	}
277
278	/* clear all interrupt channel map registers, 4 events per register */
279	for (i = 0; i < num_chnl_map_regs; i++)
280		pruss_intc_write_reg(intc, PRU_INTC_CMR(i), 0);
281
282	/* clear all host interrupt map registers, 4 channels per register */
283	for (i = 0; i < num_host_intr_regs; i++)
284		pruss_intc_write_reg(intc, PRU_INTC_HMR(i), 0);
285
286	/* global interrupt enable */
287	pruss_intc_write_reg(intc, PRU_INTC_GER, 1);
288}
289
290static void pruss_intc_irq_ack(struct irq_data *data)
291{
292	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
293	unsigned int hwirq = data->hwirq;
294
295	pruss_intc_write_reg(intc, PRU_INTC_SICR, hwirq);
296}
297
298static void pruss_intc_irq_mask(struct irq_data *data)
299{
300	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
301	unsigned int hwirq = data->hwirq;
302
303	pruss_intc_write_reg(intc, PRU_INTC_EICR, hwirq);
304}
305
306static void pruss_intc_irq_unmask(struct irq_data *data)
307{
308	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
309	unsigned int hwirq = data->hwirq;
310
311	pruss_intc_write_reg(intc, PRU_INTC_EISR, hwirq);
312}
313
314static int pruss_intc_irq_reqres(struct irq_data *data)
315{
316	if (!try_module_get(THIS_MODULE))
317		return -ENODEV;
318
319	return 0;
320}
321
322static void pruss_intc_irq_relres(struct irq_data *data)
323{
324	module_put(THIS_MODULE);
325}
326
327static int pruss_intc_irq_get_irqchip_state(struct irq_data *data,
328					    enum irqchip_irq_state which,
329					    bool *state)
330{
331	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
332	u32 reg, mask, srsr;
333
334	if (which != IRQCHIP_STATE_PENDING)
335		return -EINVAL;
336
337	reg = PRU_INTC_SRSR(data->hwirq / 32);
338	mask = BIT(data->hwirq % 32);
339
340	srsr = pruss_intc_read_reg(intc, reg);
341
342	*state = !!(srsr & mask);
343
344	return 0;
345}
346
347static int pruss_intc_irq_set_irqchip_state(struct irq_data *data,
348					    enum irqchip_irq_state which,
349					    bool state)
350{
351	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
352
353	if (which != IRQCHIP_STATE_PENDING)
354		return -EINVAL;
355
356	if (state)
357		pruss_intc_write_reg(intc, PRU_INTC_SISR, data->hwirq);
358	else
359		pruss_intc_write_reg(intc, PRU_INTC_SICR, data->hwirq);
360
361	return 0;
362}
363
364static struct irq_chip pruss_irqchip = {
365	.name			= "pruss-intc",
366	.irq_ack		= pruss_intc_irq_ack,
367	.irq_mask		= pruss_intc_irq_mask,
368	.irq_unmask		= pruss_intc_irq_unmask,
369	.irq_request_resources	= pruss_intc_irq_reqres,
370	.irq_release_resources	= pruss_intc_irq_relres,
371	.irq_get_irqchip_state	= pruss_intc_irq_get_irqchip_state,
372	.irq_set_irqchip_state	= pruss_intc_irq_set_irqchip_state,
373};
374
375static int pruss_intc_validate_mapping(struct pruss_intc *intc, int event,
376				       int channel, int host)
377{
378	struct device *dev = intc->dev;
379	int ret = 0;
380
381	mutex_lock(&intc->lock);
382
383	/* check if sysevent already assigned */
384	if (intc->event_channel[event].ref_count > 0 &&
385	    intc->event_channel[event].value != channel) {
386		dev_err(dev, "event %d (req. ch %d) already assigned to channel %d\n",
387			event, channel, intc->event_channel[event].value);
388		ret = -EBUSY;
389		goto unlock;
390	}
391
392	/* check if channel already assigned */
393	if (intc->channel_host[channel].ref_count > 0 &&
394	    intc->channel_host[channel].value != host) {
395		dev_err(dev, "channel %d (req. host %d) already assigned to host %d\n",
396			channel, host, intc->channel_host[channel].value);
397		ret = -EBUSY;
398		goto unlock;
399	}
400
401	intc->event_channel[event].value = channel;
402	intc->channel_host[channel].value = host;
403
404unlock:
405	mutex_unlock(&intc->lock);
406	return ret;
407}
408
409static int
410pruss_intc_irq_domain_xlate(struct irq_domain *d, struct device_node *node,
411			    const u32 *intspec, unsigned int intsize,
412			    unsigned long *out_hwirq, unsigned int *out_type)
413{
414	struct pruss_intc *intc = d->host_data;
415	struct device *dev = intc->dev;
416	int ret, sys_event, channel, host;
417
418	if (intsize < 3)
419		return -EINVAL;
420
421	sys_event = intspec[0];
422	if (sys_event < 0 || sys_event >= intc->soc_config->num_system_events) {
423		dev_err(dev, "%d is not valid event number\n", sys_event);
424		return -EINVAL;
425	}
426
427	channel = intspec[1];
428	if (channel < 0 || channel >= intc->soc_config->num_host_events) {
429		dev_err(dev, "%d is not valid channel number", channel);
430		return -EINVAL;
431	}
432
433	host = intspec[2];
434	if (host < 0 || host >= intc->soc_config->num_host_events) {
435		dev_err(dev, "%d is not valid host irq number\n", host);
436		return -EINVAL;
437	}
438
439	/* check if requested sys_event was already mapped, if so validate it */
440	ret = pruss_intc_validate_mapping(intc, sys_event, channel, host);
441	if (ret)
442		return ret;
443
444	*out_hwirq = sys_event;
445	*out_type = IRQ_TYPE_LEVEL_HIGH;
446
447	return 0;
448}
449
450static int pruss_intc_irq_domain_map(struct irq_domain *d, unsigned int virq,
451				     irq_hw_number_t hw)
452{
453	struct pruss_intc *intc = d->host_data;
454
455	pruss_intc_map(intc, hw);
456
457	irq_set_chip_data(virq, intc);
458	irq_set_chip_and_handler(virq, &pruss_irqchip, handle_level_irq);
459
460	return 0;
461}
462
463static void pruss_intc_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
464{
465	struct pruss_intc *intc = d->host_data;
466	unsigned long hwirq = irqd_to_hwirq(irq_get_irq_data(virq));
467
468	irq_set_chip_and_handler(virq, NULL, NULL);
469	irq_set_chip_data(virq, NULL);
470	pruss_intc_unmap(intc, hwirq);
471}
472
473static const struct irq_domain_ops pruss_intc_irq_domain_ops = {
474	.xlate	= pruss_intc_irq_domain_xlate,
475	.map	= pruss_intc_irq_domain_map,
476	.unmap	= pruss_intc_irq_domain_unmap,
477};
478
479static void pruss_intc_irq_handler(struct irq_desc *desc)
480{
481	unsigned int irq = irq_desc_get_irq(desc);
482	struct irq_chip *chip = irq_desc_get_chip(desc);
483	struct pruss_host_irq_data *host_irq_data = irq_get_handler_data(irq);
484	struct pruss_intc *intc = host_irq_data->intc;
485	u8 host_irq = host_irq_data->host_irq + FIRST_PRU_HOST_INT;
486
487	chained_irq_enter(chip, desc);
488
489	while (true) {
490		u32 hipir;
491		int hwirq, err;
492
493		/* get highest priority pending PRUSS system event */
494		hipir = pruss_intc_read_reg(intc, PRU_INTC_HIPIR(host_irq));
495		if (hipir & INTC_HIPIR_NONE_HINT)
496			break;
497
498		hwirq = hipir & GENMASK(9, 0);
499		err = generic_handle_domain_irq(intc->domain, hwirq);
500
501		/*
502		 * NOTE: manually ACK any system events that do not have a
503		 * handler mapped yet
504		 */
505		if (WARN_ON_ONCE(err))
506			pruss_intc_write_reg(intc, PRU_INTC_SICR, hwirq);
507	}
508
509	chained_irq_exit(chip, desc);
510}
511
512static const char * const irq_names[MAX_NUM_HOST_IRQS] = {
513	"host_intr0", "host_intr1", "host_intr2", "host_intr3",
514	"host_intr4", "host_intr5", "host_intr6", "host_intr7",
515};
516
517static int pruss_intc_probe(struct platform_device *pdev)
518{
519	const struct pruss_intc_match_data *data;
520	struct device *dev = &pdev->dev;
521	struct pruss_intc *intc;
522	struct pruss_host_irq_data *host_data;
523	int i, irq, ret;
524	u8 max_system_events, irqs_reserved = 0;
525
526	data = of_device_get_match_data(dev);
527	if (!data)
528		return -ENODEV;
529
530	max_system_events = data->num_system_events;
531
532	intc = devm_kzalloc(dev, sizeof(*intc), GFP_KERNEL);
533	if (!intc)
534		return -ENOMEM;
535
536	intc->soc_config = data;
537	intc->dev = dev;
538	platform_set_drvdata(pdev, intc);
539
540	intc->base = devm_platform_ioremap_resource(pdev, 0);
541	if (IS_ERR(intc->base))
542		return PTR_ERR(intc->base);
543
544	ret = of_property_read_u8(dev->of_node, "ti,irqs-reserved",
545				  &irqs_reserved);
546
547	/*
548	 * The irqs-reserved is used only for some SoC's therefore not having
549	 * this property is still valid
550	 */
551	if (ret < 0 && ret != -EINVAL)
552		return ret;
553
554	pruss_intc_init(intc);
555
556	mutex_init(&intc->lock);
557
558	intc->domain = irq_domain_add_linear(dev->of_node, max_system_events,
559					     &pruss_intc_irq_domain_ops, intc);
560	if (!intc->domain)
561		return -ENOMEM;
562
563	for (i = 0; i < MAX_NUM_HOST_IRQS; i++) {
564		if (irqs_reserved & BIT(i))
565			continue;
566
567		irq = platform_get_irq_byname(pdev, irq_names[i]);
568		if (irq < 0) {
569			ret = irq;
570			goto fail_irq;
571		}
572
573		intc->irqs[i] = irq;
574
575		host_data = devm_kzalloc(dev, sizeof(*host_data), GFP_KERNEL);
576		if (!host_data) {
577			ret = -ENOMEM;
578			goto fail_irq;
579		}
580
581		host_data->intc = intc;
582		host_data->host_irq = i;
583
584		irq_set_handler_data(irq, host_data);
585		irq_set_chained_handler(irq, pruss_intc_irq_handler);
586	}
587
588	return 0;
589
590fail_irq:
591	while (--i >= 0) {
592		if (intc->irqs[i])
593			irq_set_chained_handler_and_data(intc->irqs[i], NULL,
594							 NULL);
595	}
596
597	irq_domain_remove(intc->domain);
598
599	return ret;
600}
601
602static void pruss_intc_remove(struct platform_device *pdev)
603{
604	struct pruss_intc *intc = platform_get_drvdata(pdev);
605	u8 max_system_events = intc->soc_config->num_system_events;
606	unsigned int hwirq;
607	int i;
608
609	for (i = 0; i < MAX_NUM_HOST_IRQS; i++) {
610		if (intc->irqs[i])
611			irq_set_chained_handler_and_data(intc->irqs[i], NULL,
612							 NULL);
613	}
614
615	for (hwirq = 0; hwirq < max_system_events; hwirq++)
616		irq_dispose_mapping(irq_find_mapping(intc->domain, hwirq));
617
618	irq_domain_remove(intc->domain);
619}
620
621static const struct pruss_intc_match_data pruss_intc_data = {
622	.num_system_events = 64,
623	.num_host_events = 10,
624};
625
626static const struct pruss_intc_match_data icssg_intc_data = {
627	.num_system_events = 160,
628	.num_host_events = 20,
629};
630
631static const struct of_device_id pruss_intc_of_match[] = {
632	{
633		.compatible = "ti,pruss-intc",
634		.data = &pruss_intc_data,
635	},
636	{
637		.compatible = "ti,icssg-intc",
638		.data = &icssg_intc_data,
639	},
640	{ /* sentinel */ },
641};
642MODULE_DEVICE_TABLE(of, pruss_intc_of_match);
643
644static struct platform_driver pruss_intc_driver = {
645	.driver = {
646		.name			= "pruss-intc",
647		.of_match_table		= pruss_intc_of_match,
648		.suppress_bind_attrs	= true,
649	},
650	.probe		= pruss_intc_probe,
651	.remove_new	= pruss_intc_remove,
652};
653module_platform_driver(pruss_intc_driver);
654
655MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
656MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
657MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>");
658MODULE_DESCRIPTION("TI PRU-ICSS INTC Driver");
659MODULE_LICENSE("GPL v2");
660