1// SPDX-License-Identifier: GPL-2.0
2
3#define pr_fmt(fmt) "mvebu-sei: " fmt
4
5#include <linux/interrupt.h>
6#include <linux/irq.h>
7#include <linux/irqchip.h>
8#include <linux/irqchip/chained_irq.h>
9#include <linux/irqdomain.h>
10#include <linux/kernel.h>
11#include <linux/msi.h>
12#include <linux/platform_device.h>
13#include <linux/of_address.h>
14#include <linux/of_irq.h>
15#include <linux/of_platform.h>
16
17/* Cause register */
18#define GICP_SECR(idx)		(0x0  + ((idx) * 0x4))
19/* Mask register */
20#define GICP_SEMR(idx)		(0x20 + ((idx) * 0x4))
21#define GICP_SET_SEI_OFFSET	0x30
22
23#define SEI_IRQ_COUNT_PER_REG	32
24#define SEI_IRQ_REG_COUNT	2
25#define SEI_IRQ_COUNT		(SEI_IRQ_COUNT_PER_REG * SEI_IRQ_REG_COUNT)
26#define SEI_IRQ_REG_IDX(irq_id)	((irq_id) / SEI_IRQ_COUNT_PER_REG)
27#define SEI_IRQ_REG_BIT(irq_id)	((irq_id) % SEI_IRQ_COUNT_PER_REG)
28
29struct mvebu_sei_interrupt_range {
30	u32 first;
31	u32 size;
32};
33
34struct mvebu_sei_caps {
35	struct mvebu_sei_interrupt_range ap_range;
36	struct mvebu_sei_interrupt_range cp_range;
37};
38
39struct mvebu_sei {
40	struct device *dev;
41	void __iomem *base;
42	struct resource *res;
43	struct irq_domain *sei_domain;
44	struct irq_domain *ap_domain;
45	struct irq_domain *cp_domain;
46	const struct mvebu_sei_caps *caps;
47
48	/* Lock on MSI allocations/releases */
49	struct mutex cp_msi_lock;
50	DECLARE_BITMAP(cp_msi_bitmap, SEI_IRQ_COUNT);
51
52	/* Lock on IRQ masking register */
53	raw_spinlock_t mask_lock;
54};
55
56static void mvebu_sei_ack_irq(struct irq_data *d)
57{
58	struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
59	u32 reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
60
61	writel_relaxed(BIT(SEI_IRQ_REG_BIT(d->hwirq)),
62		       sei->base + GICP_SECR(reg_idx));
63}
64
65static void mvebu_sei_mask_irq(struct irq_data *d)
66{
67	struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
68	u32 reg, reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
69	unsigned long flags;
70
71	/* 1 disables the interrupt */
72	raw_spin_lock_irqsave(&sei->mask_lock, flags);
73	reg = readl_relaxed(sei->base + GICP_SEMR(reg_idx));
74	reg |= BIT(SEI_IRQ_REG_BIT(d->hwirq));
75	writel_relaxed(reg, sei->base + GICP_SEMR(reg_idx));
76	raw_spin_unlock_irqrestore(&sei->mask_lock, flags);
77}
78
79static void mvebu_sei_unmask_irq(struct irq_data *d)
80{
81	struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
82	u32 reg, reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
83	unsigned long flags;
84
85	/* 0 enables the interrupt */
86	raw_spin_lock_irqsave(&sei->mask_lock, flags);
87	reg = readl_relaxed(sei->base + GICP_SEMR(reg_idx));
88	reg &= ~BIT(SEI_IRQ_REG_BIT(d->hwirq));
89	writel_relaxed(reg, sei->base + GICP_SEMR(reg_idx));
90	raw_spin_unlock_irqrestore(&sei->mask_lock, flags);
91}
92
93static int mvebu_sei_set_affinity(struct irq_data *d,
94				  const struct cpumask *mask_val,
95				  bool force)
96{
97	return -EINVAL;
98}
99
100static int mvebu_sei_set_irqchip_state(struct irq_data *d,
101				       enum irqchip_irq_state which,
102				       bool state)
103{
104	/* We can only clear the pending state by acking the interrupt */
105	if (which != IRQCHIP_STATE_PENDING || state)
106		return -EINVAL;
107
108	mvebu_sei_ack_irq(d);
109	return 0;
110}
111
112static struct irq_chip mvebu_sei_irq_chip = {
113	.name			= "SEI",
114	.irq_ack		= mvebu_sei_ack_irq,
115	.irq_mask		= mvebu_sei_mask_irq,
116	.irq_unmask		= mvebu_sei_unmask_irq,
117	.irq_set_affinity       = mvebu_sei_set_affinity,
118	.irq_set_irqchip_state	= mvebu_sei_set_irqchip_state,
119};
120
121static int mvebu_sei_ap_set_type(struct irq_data *data, unsigned int type)
122{
123	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_HIGH)
124		return -EINVAL;
125
126	return 0;
127}
128
129static struct irq_chip mvebu_sei_ap_irq_chip = {
130	.name			= "AP SEI",
131	.irq_ack		= irq_chip_ack_parent,
132	.irq_mask		= irq_chip_mask_parent,
133	.irq_unmask		= irq_chip_unmask_parent,
134	.irq_set_affinity       = irq_chip_set_affinity_parent,
135	.irq_set_type		= mvebu_sei_ap_set_type,
136};
137
138static void mvebu_sei_cp_compose_msi_msg(struct irq_data *data,
139					 struct msi_msg *msg)
140{
141	struct mvebu_sei *sei = data->chip_data;
142	phys_addr_t set = sei->res->start + GICP_SET_SEI_OFFSET;
143
144	msg->data = data->hwirq + sei->caps->cp_range.first;
145	msg->address_lo = lower_32_bits(set);
146	msg->address_hi = upper_32_bits(set);
147}
148
149static int mvebu_sei_cp_set_type(struct irq_data *data, unsigned int type)
150{
151	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_EDGE_RISING)
152		return -EINVAL;
153
154	return 0;
155}
156
157static struct irq_chip mvebu_sei_cp_irq_chip = {
158	.name			= "CP SEI",
159	.irq_ack		= irq_chip_ack_parent,
160	.irq_mask		= irq_chip_mask_parent,
161	.irq_unmask		= irq_chip_unmask_parent,
162	.irq_set_affinity       = irq_chip_set_affinity_parent,
163	.irq_set_type		= mvebu_sei_cp_set_type,
164	.irq_compose_msi_msg	= mvebu_sei_cp_compose_msi_msg,
165};
166
167static int mvebu_sei_domain_alloc(struct irq_domain *domain, unsigned int virq,
168				  unsigned int nr_irqs, void *arg)
169{
170	struct mvebu_sei *sei = domain->host_data;
171	struct irq_fwspec *fwspec = arg;
172
173	/* Not much to do, just setup the irqdata */
174	irq_domain_set_hwirq_and_chip(domain, virq, fwspec->param[0],
175				      &mvebu_sei_irq_chip, sei);
176
177	return 0;
178}
179
180static void mvebu_sei_domain_free(struct irq_domain *domain, unsigned int virq,
181				  unsigned int nr_irqs)
182{
183	int i;
184
185	for (i = 0; i < nr_irqs; i++) {
186		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
187		irq_set_handler(virq + i, NULL);
188		irq_domain_reset_irq_data(d);
189	}
190}
191
192static const struct irq_domain_ops mvebu_sei_domain_ops = {
193	.alloc	= mvebu_sei_domain_alloc,
194	.free	= mvebu_sei_domain_free,
195};
196
197static int mvebu_sei_ap_translate(struct irq_domain *domain,
198				  struct irq_fwspec *fwspec,
199				  unsigned long *hwirq,
200				  unsigned int *type)
201{
202	*hwirq = fwspec->param[0];
203	*type  = IRQ_TYPE_LEVEL_HIGH;
204
205	return 0;
206}
207
208static int mvebu_sei_ap_alloc(struct irq_domain *domain, unsigned int virq,
209			      unsigned int nr_irqs, void *arg)
210{
211	struct mvebu_sei *sei = domain->host_data;
212	struct irq_fwspec fwspec;
213	unsigned long hwirq;
214	unsigned int type;
215	int err;
216
217	mvebu_sei_ap_translate(domain, arg, &hwirq, &type);
218
219	fwspec.fwnode = domain->parent->fwnode;
220	fwspec.param_count = 1;
221	fwspec.param[0] = hwirq + sei->caps->ap_range.first;
222
223	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
224	if (err)
225		return err;
226
227	irq_domain_set_info(domain, virq, hwirq,
228			    &mvebu_sei_ap_irq_chip, sei,
229			    handle_level_irq, NULL, NULL);
230	irq_set_probe(virq);
231
232	return 0;
233}
234
235static const struct irq_domain_ops mvebu_sei_ap_domain_ops = {
236	.translate	= mvebu_sei_ap_translate,
237	.alloc		= mvebu_sei_ap_alloc,
238	.free		= irq_domain_free_irqs_parent,
239};
240
241static void mvebu_sei_cp_release_irq(struct mvebu_sei *sei, unsigned long hwirq)
242{
243	mutex_lock(&sei->cp_msi_lock);
244	clear_bit(hwirq, sei->cp_msi_bitmap);
245	mutex_unlock(&sei->cp_msi_lock);
246}
247
248static int mvebu_sei_cp_domain_alloc(struct irq_domain *domain,
249				     unsigned int virq, unsigned int nr_irqs,
250				     void *args)
251{
252	struct mvebu_sei *sei = domain->host_data;
253	struct irq_fwspec fwspec;
254	unsigned long hwirq;
255	int ret;
256
257	/* The software only supports single allocations for now */
258	if (nr_irqs != 1)
259		return -ENOTSUPP;
260
261	mutex_lock(&sei->cp_msi_lock);
262	hwirq = find_first_zero_bit(sei->cp_msi_bitmap,
263				    sei->caps->cp_range.size);
264	if (hwirq < sei->caps->cp_range.size)
265		set_bit(hwirq, sei->cp_msi_bitmap);
266	mutex_unlock(&sei->cp_msi_lock);
267
268	if (hwirq == sei->caps->cp_range.size)
269		return -ENOSPC;
270
271	fwspec.fwnode = domain->parent->fwnode;
272	fwspec.param_count = 1;
273	fwspec.param[0] = hwirq + sei->caps->cp_range.first;
274
275	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
276	if (ret)
277		goto free_irq;
278
279	irq_domain_set_info(domain, virq, hwirq,
280			    &mvebu_sei_cp_irq_chip, sei,
281			    handle_edge_irq, NULL, NULL);
282
283	return 0;
284
285free_irq:
286	mvebu_sei_cp_release_irq(sei, hwirq);
287	return ret;
288}
289
290static void mvebu_sei_cp_domain_free(struct irq_domain *domain,
291				     unsigned int virq, unsigned int nr_irqs)
292{
293	struct mvebu_sei *sei = domain->host_data;
294	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
295
296	if (nr_irqs != 1 || d->hwirq >= sei->caps->cp_range.size) {
297		dev_err(sei->dev, "Invalid hwirq %lu\n", d->hwirq);
298		return;
299	}
300
301	mvebu_sei_cp_release_irq(sei, d->hwirq);
302	irq_domain_free_irqs_parent(domain, virq, 1);
303}
304
305static const struct irq_domain_ops mvebu_sei_cp_domain_ops = {
306	.alloc	= mvebu_sei_cp_domain_alloc,
307	.free	= mvebu_sei_cp_domain_free,
308};
309
310static struct irq_chip mvebu_sei_msi_irq_chip = {
311	.name		= "SEI pMSI",
312	.irq_ack	= irq_chip_ack_parent,
313	.irq_set_type	= irq_chip_set_type_parent,
314};
315
316static struct msi_domain_ops mvebu_sei_msi_ops = {
317};
318
319static struct msi_domain_info mvebu_sei_msi_domain_info = {
320	.flags	= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS,
321	.ops	= &mvebu_sei_msi_ops,
322	.chip	= &mvebu_sei_msi_irq_chip,
323};
324
325static void mvebu_sei_handle_cascade_irq(struct irq_desc *desc)
326{
327	struct mvebu_sei *sei = irq_desc_get_handler_data(desc);
328	struct irq_chip *chip = irq_desc_get_chip(desc);
329	u32 idx;
330
331	chained_irq_enter(chip, desc);
332
333	for (idx = 0; idx < SEI_IRQ_REG_COUNT; idx++) {
334		unsigned long irqmap;
335		int bit;
336
337		irqmap = readl_relaxed(sei->base + GICP_SECR(idx));
338		for_each_set_bit(bit, &irqmap, SEI_IRQ_COUNT_PER_REG) {
339			unsigned long hwirq;
340			int err;
341
342			hwirq = idx * SEI_IRQ_COUNT_PER_REG + bit;
343			err = generic_handle_domain_irq(sei->sei_domain, hwirq);
344			if (unlikely(err))
345				dev_warn(sei->dev, "Spurious IRQ detected (hwirq %lu)\n", hwirq);
346		}
347	}
348
349	chained_irq_exit(chip, desc);
350}
351
352static void mvebu_sei_reset(struct mvebu_sei *sei)
353{
354	u32 reg_idx;
355
356	/* Clear IRQ cause registers, mask all interrupts */
357	for (reg_idx = 0; reg_idx < SEI_IRQ_REG_COUNT; reg_idx++) {
358		writel_relaxed(0xFFFFFFFF, sei->base + GICP_SECR(reg_idx));
359		writel_relaxed(0xFFFFFFFF, sei->base + GICP_SEMR(reg_idx));
360	}
361}
362
363static int mvebu_sei_probe(struct platform_device *pdev)
364{
365	struct device_node *node = pdev->dev.of_node;
366	struct irq_domain *plat_domain;
367	struct mvebu_sei *sei;
368	u32 parent_irq;
369	int ret;
370
371	sei = devm_kzalloc(&pdev->dev, sizeof(*sei), GFP_KERNEL);
372	if (!sei)
373		return -ENOMEM;
374
375	sei->dev = &pdev->dev;
376
377	mutex_init(&sei->cp_msi_lock);
378	raw_spin_lock_init(&sei->mask_lock);
379
380	sei->base = devm_platform_get_and_ioremap_resource(pdev, 0, &sei->res);
381	if (IS_ERR(sei->base))
382		return PTR_ERR(sei->base);
383
384	/* Retrieve the SEI capabilities with the interrupt ranges */
385	sei->caps = of_device_get_match_data(&pdev->dev);
386	if (!sei->caps) {
387		dev_err(sei->dev,
388			"Could not retrieve controller capabilities\n");
389		return -EINVAL;
390	}
391
392	/*
393	 * Reserve the single (top-level) parent SPI IRQ from which all the
394	 * interrupts handled by this driver will be signaled.
395	 */
396	parent_irq = irq_of_parse_and_map(node, 0);
397	if (parent_irq <= 0) {
398		dev_err(sei->dev, "Failed to retrieve top-level SPI IRQ\n");
399		return -ENODEV;
400	}
401
402	/* Create the root SEI domain */
403	sei->sei_domain = irq_domain_create_linear(of_node_to_fwnode(node),
404						   (sei->caps->ap_range.size +
405						    sei->caps->cp_range.size),
406						   &mvebu_sei_domain_ops,
407						   sei);
408	if (!sei->sei_domain) {
409		dev_err(sei->dev, "Failed to create SEI IRQ domain\n");
410		ret = -ENOMEM;
411		goto dispose_irq;
412	}
413
414	irq_domain_update_bus_token(sei->sei_domain, DOMAIN_BUS_NEXUS);
415
416	/* Create the 'wired' domain */
417	sei->ap_domain = irq_domain_create_hierarchy(sei->sei_domain, 0,
418						     sei->caps->ap_range.size,
419						     of_node_to_fwnode(node),
420						     &mvebu_sei_ap_domain_ops,
421						     sei);
422	if (!sei->ap_domain) {
423		dev_err(sei->dev, "Failed to create AP IRQ domain\n");
424		ret = -ENOMEM;
425		goto remove_sei_domain;
426	}
427
428	irq_domain_update_bus_token(sei->ap_domain, DOMAIN_BUS_WIRED);
429
430	/* Create the 'MSI' domain */
431	sei->cp_domain = irq_domain_create_hierarchy(sei->sei_domain, 0,
432						     sei->caps->cp_range.size,
433						     of_node_to_fwnode(node),
434						     &mvebu_sei_cp_domain_ops,
435						     sei);
436	if (!sei->cp_domain) {
437		pr_err("Failed to create CPs IRQ domain\n");
438		ret = -ENOMEM;
439		goto remove_ap_domain;
440	}
441
442	irq_domain_update_bus_token(sei->cp_domain, DOMAIN_BUS_GENERIC_MSI);
443
444	plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
445						     &mvebu_sei_msi_domain_info,
446						     sei->cp_domain);
447	if (!plat_domain) {
448		pr_err("Failed to create CPs MSI domain\n");
449		ret = -ENOMEM;
450		goto remove_cp_domain;
451	}
452
453	mvebu_sei_reset(sei);
454
455	irq_set_chained_handler_and_data(parent_irq,
456					 mvebu_sei_handle_cascade_irq,
457					 sei);
458
459	return 0;
460
461remove_cp_domain:
462	irq_domain_remove(sei->cp_domain);
463remove_ap_domain:
464	irq_domain_remove(sei->ap_domain);
465remove_sei_domain:
466	irq_domain_remove(sei->sei_domain);
467dispose_irq:
468	irq_dispose_mapping(parent_irq);
469
470	return ret;
471}
472
473static struct mvebu_sei_caps mvebu_sei_ap806_caps = {
474	.ap_range = {
475		.first = 0,
476		.size = 21,
477	},
478	.cp_range = {
479		.first = 21,
480		.size = 43,
481	},
482};
483
484static const struct of_device_id mvebu_sei_of_match[] = {
485	{
486		.compatible = "marvell,ap806-sei",
487		.data = &mvebu_sei_ap806_caps,
488	},
489	{},
490};
491
492static struct platform_driver mvebu_sei_driver = {
493	.probe  = mvebu_sei_probe,
494	.driver = {
495		.name = "mvebu-sei",
496		.of_match_table = mvebu_sei_of_match,
497	},
498};
499builtin_platform_driver(mvebu_sei_driver);
500