[linux-block.git] / drivers / irqchip / irq-al-fic.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 */

#include <linux/bitfield.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

/* FIC Registers */
#define AL_FIC_CAUSE		0x00
#define AL_FIC_SET_CAUSE	0x08
#define AL_FIC_MASK		0x10
#define AL_FIC_CONTROL		0x28

#define CONTROL_TRIGGER_RISING	BIT(3)
#define CONTROL_MASK_MSI_X	BIT(5)

#define NR_FIC_IRQS 32

MODULE_AUTHOR("Talel Shenhar");
MODULE_DESCRIPTION("Amazon's Annapurna Labs Interrupt Controller Driver");
MODULE_LICENSE("GPL v2");

enum al_fic_state {
	AL_FIC_UNCONFIGURED = 0,
	AL_FIC_CONFIGURED_LEVEL,
	AL_FIC_CONFIGURED_RISING_EDGE,
};

struct al_fic {
	void __iomem *base;
	struct irq_domain *domain;
	const char *name;
	unsigned int parent_irq;
	enum al_fic_state state;
};

static void al_fic_set_trigger(struct al_fic *fic,
			       struct irq_chip_generic *gc,
			       enum al_fic_state new_state)
{
	irq_flow_handler_t handler;
	u32 control = readl_relaxed(fic->base + AL_FIC_CONTROL);

	if (new_state == AL_FIC_CONFIGURED_LEVEL) {
		handler = handle_level_irq;
		control &= ~CONTROL_TRIGGER_RISING;
	} else {
		handler = handle_edge_irq;
		control |= CONTROL_TRIGGER_RISING;
	}
	gc->chip_types->handler = handler;
	fic->state = new_state;
	writel_relaxed(control, fic->base + AL_FIC_CONTROL);
}

static int al_fic_irq_set_type(struct irq_data *data, unsigned int flow_type)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	struct al_fic *fic = gc->private;
	enum al_fic_state new_state;
	int ret = 0;

	irq_gc_lock(gc);

	if (((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_HIGH) &&
	    ((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_EDGE_RISING)) {
		pr_debug("fic doesn't support flow type %d\n", flow_type);
		ret = -EINVAL;
		goto err;
	}

	new_state = (flow_type & IRQ_TYPE_LEVEL_HIGH) ?
		AL_FIC_CONFIGURED_LEVEL : AL_FIC_CONFIGURED_RISING_EDGE;

	/*
	 * A given FIC instance can be either all level or all edge triggered.
	 * This is generally fixed depending on what pieces of HW it's wired up
	 * to.
	 *
	 * We configure it based on the sensitivity of the first source
	 * being setup, and reject any subsequent attempt at configuring it in a
	 * different way.
	 */
	if (fic->state == AL_FIC_UNCONFIGURED) {
		al_fic_set_trigger(fic, gc, new_state);
	} else if (fic->state != new_state) {
		pr_debug("fic %s state already configured to %d\n",
			 fic->name, fic->state);
		ret = -EINVAL;
		goto err;
	}

err:
	irq_gc_unlock(gc);

	return ret;
}

static void al_fic_irq_handler(struct irq_desc *desc)
{
	struct al_fic *fic = irq_desc_get_handler_data(desc);
	struct irq_domain *domain = fic->domain;
	struct irq_chip *irqchip = irq_desc_get_chip(desc);
	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
	unsigned long pending;
	u32 hwirq;

	chained_irq_enter(irqchip, desc);

	pending = readl_relaxed(fic->base + AL_FIC_CAUSE);
	pending &= ~gc->mask_cache;

	for_each_set_bit(hwirq, &pending, NR_FIC_IRQS)
		generic_handle_domain_irq(domain, hwirq);

	chained_irq_exit(irqchip, desc);
}

static int al_fic_irq_retrigger(struct irq_data *data)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	struct al_fic *fic = gc->private;

	writel_relaxed(BIT(data->hwirq), fic->base + AL_FIC_SET_CAUSE);

	return 1;
}

static int al_fic_register(struct device_node *node,
			   struct al_fic *fic)
{
	struct irq_chip_generic *gc;
	int ret;

	fic->domain = irq_domain_add_linear(node,
					    NR_FIC_IRQS,
					    &irq_generic_chip_ops,
					    fic);
	if (!fic->domain) {
		pr_err("fail to add irq domain\n");
		return -ENOMEM;
	}

	ret = irq_alloc_domain_generic_chips(fic->domain,
					     NR_FIC_IRQS,
					     1, fic->name,
					     handle_level_irq,
					     0, 0, IRQ_GC_INIT_MASK_CACHE);
	if (ret) {
		pr_err("fail to allocate generic chip (%d)\n", ret);
		goto err_domain_remove;
	}

	gc = irq_get_domain_generic_chip(fic->domain, 0);
	gc->reg_base = fic->base;
	gc->chip_types->regs.mask = AL_FIC_MASK;
	gc->chip_types->regs.ack = AL_FIC_CAUSE;
	gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
	gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;
	gc->chip_types->chip.irq_ack = irq_gc_ack_clr_bit;
	gc->chip_types->chip.irq_set_type = al_fic_irq_set_type;
	gc->chip_types->chip.irq_retrigger = al_fic_irq_retrigger;
	gc->chip_types->chip.flags = IRQCHIP_SKIP_SET_WAKE;
	gc->private = fic;

	irq_set_chained_handler_and_data(fic->parent_irq,
					 al_fic_irq_handler,
					 fic);
	return 0;

err_domain_remove:
	irq_domain_remove(fic->domain);

	return ret;
}

/*
 * al_fic_wire_init() - initialize and configure fic in wire mode
 * @of_node: optional pointer to interrupt controller's device tree node.
 * @base: mmio to fic register
 * @name: name of the fic
 * @parent_irq: interrupt of parent
 *
 * This API will configure the fic hardware to to work in wire mode.
 * In wire mode, fic hardware is generating a wire ("wired") interrupt.
 * Interrupt can be generated based on positive edge or level - configuration is
 * to be determined based on connected hardware to this fic.
 */
static struct al_fic *al_fic_wire_init(struct device_node *node,
				       void __iomem *base,
				       const char *name,
				       unsigned int parent_irq)
{
	struct al_fic *fic;
	int ret;
	u32 control = CONTROL_MASK_MSI_X;

	fic = kzalloc(sizeof(*fic), GFP_KERNEL);
	if (!fic)
		return ERR_PTR(-ENOMEM);

	fic->base = base;
	fic->parent_irq = parent_irq;
	fic->name = name;

	/* mask out all interrupts */
	writel_relaxed(0xFFFFFFFF, fic->base + AL_FIC_MASK);

	/* clear any pending interrupt */
	writel_relaxed(0, fic->base + AL_FIC_CAUSE);

	writel_relaxed(control, fic->base + AL_FIC_CONTROL);

	ret = al_fic_register(node, fic);
	if (ret) {
		pr_err("fail to register irqchip\n");
		goto err_free;
	}

	pr_debug("%s initialized successfully in Legacy mode (parent-irq=%u)\n",
		 fic->name, parent_irq);

	return fic;

err_free:
	kfree(fic);
	return ERR_PTR(ret);
}

static int __init al_fic_init_dt(struct device_node *node,
				 struct device_node *parent)
{
	int ret;
	void __iomem *base;
	unsigned int parent_irq;
	struct al_fic *fic;

	if (!parent) {
		pr_err("%s: unsupported - device require a parent\n",
		       node->name);
		return -EINVAL;
	}

	base = of_iomap(node, 0);
	if (!base) {
		pr_err("%s: fail to map memory\n", node->name);
		return -ENOMEM;
	}

	parent_irq = irq_of_parse_and_map(node, 0);
	if (!parent_irq) {
		pr_err("%s: fail to map irq\n", node->name);
		ret = -EINVAL;
		goto err_unmap;
	}

	fic = al_fic_wire_init(node,
			       base,
			       node->name,
			       parent_irq);
	if (IS_ERR(fic)) {
		pr_err("%s: fail to initialize irqchip (%lu)\n",
		       node->name,
		       PTR_ERR(fic));
		ret = PTR_ERR(fic);
		goto err_irq_dispose;
	}

	return 0;

err_irq_dispose:
	irq_dispose_mapping(parent_irq);
err_unmap:
	iounmap(base);

	return ret;
}

IRQCHIP_DECLARE(al_fic, "amazon,al-fic", al_fic_init_dt);
Commit	Line	Data
1eb77c3b TS	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
	4	*/
	5
	6	#include <linux/bitfield.h>
	7	#include <linux/irq.h>
	8	#include <linux/irqchip.h>
	9	#include <linux/irqchip/chained_irq.h>
	10	#include <linux/irqdomain.h>
	11	#include <linux/module.h>
	12	#include <linux/of.h>
	13	#include <linux/of_address.h>
	14	#include <linux/of_irq.h>
	15
	16	/* FIC Registers */
	17	#define AL_FIC_CAUSE 0x00
9c426b77	18	#define AL_FIC_SET_CAUSE 0x08
1eb77c3b TS	19	#define AL_FIC_MASK 0x10
	20	#define AL_FIC_CONTROL 0x28
	21
	22	#define CONTROL_TRIGGER_RISING BIT(3)
	23	#define CONTROL_MASK_MSI_X BIT(5)
	24
	25	#define NR_FIC_IRQS 32
	26
	27	MODULE_AUTHOR("Talel Shenhar");
	28	MODULE_DESCRIPTION("Amazon's Annapurna Labs Interrupt Controller Driver");
	29	MODULE_LICENSE("GPL v2");
	30
	31	enum al_fic_state {
	32	AL_FIC_UNCONFIGURED = 0,
	33	AL_FIC_CONFIGURED_LEVEL,
	34	AL_FIC_CONFIGURED_RISING_EDGE,
	35	};
	36
	37	struct al_fic {
	38	void __iomem *base;
	39	struct irq_domain *domain;
	40	const char *name;
	41	unsigned int parent_irq;
	42	enum al_fic_state state;
	43	};
	44
	45	static void al_fic_set_trigger(struct al_fic *fic,
	46	struct irq_chip_generic *gc,
	47	enum al_fic_state new_state)
	48	{
	49	irq_flow_handler_t handler;
	50	u32 control = readl_relaxed(fic->base + AL_FIC_CONTROL);
	51
	52	if (new_state == AL_FIC_CONFIGURED_LEVEL) {
	53	handler = handle_level_irq;
	54	control &= ~CONTROL_TRIGGER_RISING;
	55	} else {
	56	handler = handle_edge_irq;
	57	control \|= CONTROL_TRIGGER_RISING;
	58	}
	59	gc->chip_types->handler = handler;
	60	fic->state = new_state;
	61	writel_relaxed(control, fic->base + AL_FIC_CONTROL);
	62	}
	63
	64	static int al_fic_irq_set_type(struct irq_data *data, unsigned int flow_type)
	65	{
	66	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	67	struct al_fic *fic = gc->private;
	68	enum al_fic_state new_state;
	69	int ret = 0;
	70
	71	irq_gc_lock(gc);
	72
	73	if (((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_HIGH) &&
	74	((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_EDGE_RISING)) {
	75	pr_debug("fic doesn't support flow type %d\n", flow_type);
	76	ret = -EINVAL;
	77	goto err;
	78	}
	79
	80	new_state = (flow_type & IRQ_TYPE_LEVEL_HIGH) ?
	81	AL_FIC_CONFIGURED_LEVEL : AL_FIC_CONFIGURED_RISING_EDGE;
	82
83	/*
84	* A given FIC instance can be either all level or all edge triggered.
85	* This is generally fixed depending on what pieces of HW it's wired up
86	* to.
87	*
88	* We configure it based on the sensitivity of the first source
89	* being setup, and reject any subsequent attempt at configuring it in a
90	* different way.
91	*/
92	if (fic->state == AL_FIC_UNCONFIGURED) {
93	al_fic_set_trigger(fic, gc, new_state);
94	} else if (fic->state != new_state) {
95	pr_debug("fic %s state already configured to %d\n",
96	fic->name, fic->state);
97	ret = -EINVAL;
98	goto err;
99	}
100
101	err:
102	irq_gc_unlock(gc);
103
104	return ret;
105	}
106
107	static void al_fic_irq_handler(struct irq_desc *desc)
108	{
109	struct al_fic *fic = irq_desc_get_handler_data(desc);
110	struct irq_domain *domain = fic->domain;
111	struct irq_chip *irqchip = irq_desc_get_chip(desc);
112	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
113	unsigned long pending;
1eb77c3b TS	114	u32 hwirq;
	115
	116	chained_irq_enter(irqchip, desc);
	117
	118	pending = readl_relaxed(fic->base + AL_FIC_CAUSE);
	119	pending &= ~gc->mask_cache;
	120
046a6ee2 MZ	121	for_each_set_bit(hwirq, &pending, NR_FIC_IRQS)
046a6ee2 MZ	122	generic_handle_domain_irq(domain, hwirq);
1eb77c3b TS	123
	124	chained_irq_exit(irqchip, desc);
	125	}
	126
9c426b77 TS	127	static int al_fic_irq_retrigger(struct irq_data *data)
	128	{
	129	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	130	struct al_fic *fic = gc->private;
	131
	132	writel_relaxed(BIT(data->hwirq), fic->base + AL_FIC_SET_CAUSE);
	133
	134	return 1;
	135	}
	136
1eb77c3b TS	137	static int al_fic_register(struct device_node *node,
	138	struct al_fic *fic)
	139	{
	140	struct irq_chip_generic *gc;
	141	int ret;
	142
	143	fic->domain = irq_domain_add_linear(node,
	144	NR_FIC_IRQS,
	145	&irq_generic_chip_ops,
	146	fic);
	147	if (!fic->domain) {
	148	pr_err("fail to add irq domain\n");
	149	return -ENOMEM;
	150	}
	151
	152	ret = irq_alloc_domain_generic_chips(fic->domain,
	153	NR_FIC_IRQS,
	154	1, fic->name,
	155	handle_level_irq,
	156	0, 0, IRQ_GC_INIT_MASK_CACHE);
	157	if (ret) {
	158	pr_err("fail to allocate generic chip (%d)\n", ret);
	159	goto err_domain_remove;
	160	}
	161
	162	gc = irq_get_domain_generic_chip(fic->domain, 0);
	163	gc->reg_base = fic->base;
	164	gc->chip_types->regs.mask = AL_FIC_MASK;
	165	gc->chip_types->regs.ack = AL_FIC_CAUSE;
	166	gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
	167	gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;
	168	gc->chip_types->chip.irq_ack = irq_gc_ack_clr_bit;
	169	gc->chip_types->chip.irq_set_type = al_fic_irq_set_type;
9c426b77	170	gc->chip_types->chip.irq_retrigger = al_fic_irq_retrigger;
1eb77c3b TS	171	gc->chip_types->chip.flags = IRQCHIP_SKIP_SET_WAKE;
	172	gc->private = fic;
	173
	174	irq_set_chained_handler_and_data(fic->parent_irq,
	175	al_fic_irq_handler,
	176	fic);
	177	return 0;
	178
	179	err_domain_remove:
	180	irq_domain_remove(fic->domain);
	181
	182	return ret;
	183	}
	184
	185	/*
	186	* al_fic_wire_init() - initialize and configure fic in wire mode
	187	* @of_node: optional pointer to interrupt controller's device tree node.
	188	* @base: mmio to fic register
	189	* @name: name of the fic
	190	* @parent_irq: interrupt of parent
	191	*
	192	* This API will configure the fic hardware to to work in wire mode.
	193	* In wire mode, fic hardware is generating a wire ("wired") interrupt.
	194	* Interrupt can be generated based on positive edge or level - configuration is
	195	* to be determined based on connected hardware to this fic.
	196	*/
	197	static struct al_fic al_fic_wire_init(struct device_node node,
	198	void __iomem *base,
	199	const char *name,
	200	unsigned int parent_irq)
	201	{
	202	struct al_fic *fic;
	203	int ret;
	204	u32 control = CONTROL_MASK_MSI_X;
	205
	206	fic = kzalloc(sizeof(*fic), GFP_KERNEL);
	207	if (!fic)
	208	return ERR_PTR(-ENOMEM);
	209
	210	fic->base = base;
	211	fic->parent_irq = parent_irq;
	212	fic->name = name;
	213
	214	/* mask out all interrupts */
	215	writel_relaxed(0xFFFFFFFF, fic->base + AL_FIC_MASK);
	216
	217	/* clear any pending interrupt */
	218	writel_relaxed(0, fic->base + AL_FIC_CAUSE);
	219
	220	writel_relaxed(control, fic->base + AL_FIC_CONTROL);
	221
	222	ret = al_fic_register(node, fic);
	223	if (ret) {
	224	pr_err("fail to register irqchip\n");
	225	goto err_free;
	226	}
	227
	228	pr_debug("%s initialized successfully in Legacy mode (parent-irq=%u)\n",
	229	fic->name, parent_irq);
	230
	231	return fic;
	232
	233	err_free:
	234	kfree(fic);
235	return ERR_PTR(ret);
236	}
237
238	static int __init al_fic_init_dt(struct device_node *node,
239	struct device_node *parent)
240	{
241	int ret;
242	void __iomem *base;
243	unsigned int parent_irq;
244	struct al_fic *fic;
245
246	if (!parent) {
247	pr_err("%s: unsupported - device require a parent\n",
248	node->name);
249	return -EINVAL;
250	}
251
252	base = of_iomap(node, 0);
253	if (!base) {
254	pr_err("%s: fail to map memory\n", node->name);
255	return -ENOMEM;
256	}
257
258	parent_irq = irq_of_parse_and_map(node, 0);
259	if (!parent_irq) {
260	pr_err("%s: fail to map irq\n", node->name);
261	ret = -EINVAL;
262	goto err_unmap;
263	}
264
265	fic = al_fic_wire_init(node,
266	base,
267	node->name,
268	parent_irq);
269	if (IS_ERR(fic)) {
270	pr_err("%s: fail to initialize irqchip (%lu)\n",
271	node->name,
272	PTR_ERR(fic));
273	ret = PTR_ERR(fic);
274	goto err_irq_dispose;
275	}
276
277	return 0;
278
279	err_irq_dispose:
280	irq_dispose_mapping(parent_irq);
281	err_unmap:
282	iounmap(base);
283
284	return ret;
285	}
286
287	IRQCHIP_DECLARE(al_fic, "amazon,al-fic", al_fic_init_dt);