hlwd-pic.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
  4 *
  5 * Nintendo Wii "Hollywood" interrupt controller support.
  6 * Copyright (C) 2009 The GameCube Linux Team
  7 * Copyright (C) 2009 Albert Herranz
  8 */
  9#define DRV_MODULE_NAME "hlwd-pic"
 10#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
 11
 12#include <linux/kernel.h>
 13#include <linux/irq.h>
 14#include <linux/of.h>
 15#include <linux/of_address.h>
 16#include <linux/of_irq.h>
 17#include <asm/io.h>
 18
 19#include "hlwd-pic.h"
 20
 21#define HLWD_NR_IRQS	32
 22
 23/*
 24 * Each interrupt has a corresponding bit in both
 25 * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
 26 *
 27 * Enabling/disabling an interrupt line involves asserting/clearing
 28 * the corresponding bit in IMR. ACK'ing a request simply involves
 29 * asserting the corresponding bit in ICR.
 30 */
 31#define HW_BROADWAY_ICR		0x00
 32#define HW_BROADWAY_IMR		0x04
 33#define HW_STARLET_ICR		0x08
 34#define HW_STARLET_IMR		0x0c
 35
 36
 37/*
 38 * IRQ chip hooks.
 39 *
 40 */
 41
 42static void hlwd_pic_mask_and_ack(struct irq_data *d)
 43{
 44	int irq = irqd_to_hwirq(d);
 45	void __iomem *io_base = irq_data_get_irq_chip_data(d);
 46	u32 mask = 1 << irq;
 47
 48	clrbits32(io_base + HW_BROADWAY_IMR, mask);
 49	out_be32(io_base + HW_BROADWAY_ICR, mask);
 50}
 51
 52static void hlwd_pic_ack(struct irq_data *d)
 53{
 54	int irq = irqd_to_hwirq(d);
 55	void __iomem *io_base = irq_data_get_irq_chip_data(d);
 56
 57	out_be32(io_base + HW_BROADWAY_ICR, 1 << irq);
 58}
 59
 60static void hlwd_pic_mask(struct irq_data *d)
 61{
 62	int irq = irqd_to_hwirq(d);
 63	void __iomem *io_base = irq_data_get_irq_chip_data(d);
 64
 65	clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
 66}
 67
 68static void hlwd_pic_unmask(struct irq_data *d)
 69{
 70	int irq = irqd_to_hwirq(d);
 71	void __iomem *io_base = irq_data_get_irq_chip_data(d);
 72
 73	setbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
 74
 75	/* Make sure the ARM (aka. Starlet) doesn't handle this interrupt. */
 76	clrbits32(io_base + HW_STARLET_IMR, 1 << irq);
 77}
 78
 79
 80static struct irq_chip hlwd_pic = {
 81	.name		= "hlwd-pic",
 82	.irq_ack	= hlwd_pic_ack,
 83	.irq_mask_ack	= hlwd_pic_mask_and_ack,
 84	.irq_mask	= hlwd_pic_mask,
 85	.irq_unmask	= hlwd_pic_unmask,
 86};
 87
 88/*
 89 * IRQ host hooks.
 90 *
 91 */
 92
 93static struct irq_domain *hlwd_irq_host;
 94
 95static int hlwd_pic_map(struct irq_domain *h, unsigned int virq,
 96			   irq_hw_number_t hwirq)
 97{
 98	irq_set_chip_data(virq, h->host_data);
 99	irq_set_status_flags(virq, IRQ_LEVEL);
100	irq_set_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
101	return 0;
102}
103
104static const struct irq_domain_ops hlwd_irq_domain_ops = {
105	.map = hlwd_pic_map,
106};
107
108static unsigned int __hlwd_pic_get_irq(struct irq_domain *h)
109{
110	void __iomem *io_base = h->host_data;
111	u32 irq_status;
112
113	irq_status = in_be32(io_base + HW_BROADWAY_ICR) &
114		     in_be32(io_base + HW_BROADWAY_IMR);
115	if (irq_status == 0)
116		return 0;	/* no more IRQs pending */
117
118	return __ffs(irq_status);
119}
120
121static void hlwd_pic_irq_cascade(struct irq_desc *desc)
122{
123	struct irq_chip *chip = irq_desc_get_chip(desc);
124	struct irq_domain *irq_domain = irq_desc_get_handler_data(desc);
125	unsigned int hwirq;
126
127	raw_spin_lock(&desc->lock);
128	chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */
129	raw_spin_unlock(&desc->lock);
130
131	hwirq = __hlwd_pic_get_irq(irq_domain);
132	if (hwirq)
133		generic_handle_domain_irq(irq_domain, hwirq);
134	else
135		pr_err("spurious interrupt!\n");
136
137	raw_spin_lock(&desc->lock);
138	chip->irq_ack(&desc->irq_data); /* IRQ_LEVEL */
139	if (!irqd_irq_disabled(&desc->irq_data) && chip->irq_unmask)
140		chip->irq_unmask(&desc->irq_data);
141	raw_spin_unlock(&desc->lock);
142}
143
144/*
145 * Platform hooks.
146 *
147 */
148
149static void __hlwd_quiesce(void __iomem *io_base)
150{
151	/* mask and ack all IRQs */
152	out_be32(io_base + HW_BROADWAY_IMR, 0);
153	out_be32(io_base + HW_BROADWAY_ICR, 0xffffffff);
154}
155
156static struct irq_domain *__init hlwd_pic_init(struct device_node *np)
157{
158	struct irq_domain *irq_domain;
159	struct resource res;
160	void __iomem *io_base;
161	int retval;
162
163	retval = of_address_to_resource(np, 0, &res);
164	if (retval) {
165		pr_err("no io memory range found\n");
166		return NULL;
167	}
168	io_base = ioremap(res.start, resource_size(&res));
169	if (!io_base) {
170		pr_err("ioremap failed\n");
171		return NULL;
172	}
173
174	pr_info("controller at 0x%pa mapped to 0x%p\n", &res.start, io_base);
175
176	__hlwd_quiesce(io_base);
177
178	irq_domain = irq_domain_create_linear(of_fwnode_handle(np),
179					      HLWD_NR_IRQS,
180					      &hlwd_irq_domain_ops, io_base);
181	if (!irq_domain) {
182		pr_err("failed to allocate irq_domain\n");
183		iounmap(io_base);
184		return NULL;
185	}
186
187	return irq_domain;
188}
189
190unsigned int hlwd_pic_get_irq(void)
191{
192	unsigned int hwirq = __hlwd_pic_get_irq(hlwd_irq_host);
193	return hwirq ? irq_find_mapping(hlwd_irq_host, hwirq) : 0;
194}
195
196/*
197 * Probe function.
198 *
199 */
200
201void __init hlwd_pic_probe(void)
202{
203	struct irq_domain *host;
204	struct device_node *np;
205	const u32 *interrupts;
206	int cascade_virq;
207
208	for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") {
209		interrupts = of_get_property(np, "interrupts", NULL);
210		if (interrupts) {
211			host = hlwd_pic_init(np);
212			BUG_ON(!host);
213			cascade_virq = irq_of_parse_and_map(np, 0);
214			irq_set_handler_data(cascade_virq, host);
215			irq_set_chained_handler(cascade_virq,
216						hlwd_pic_irq_cascade);
217			hlwd_irq_host = host;
218			of_node_put(np);
219			break;
220		}
221	}
222}
223
224/**
225 * hlwd_quiesce() - quiesce hollywood irq controller
226 *
227 * Mask and ack all interrupt sources.
228 *
229 */
230void hlwd_quiesce(void)
231{
232	void __iomem *io_base = hlwd_irq_host->host_data;
233
234	__hlwd_quiesce(io_base);
235}
236