1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Texas Instruments Keystone IRQ controller IP driver
4 *
5 * Copyright (C) 2014 Texas Instruments, Inc.
6 * Author: Sajesh Kumar Saran <sajesh@ti.com>
7 *	   Grygorii Strashko <grygorii.strashko@ti.com>
8 */
9
10#include <linux/irq.h>
11#include <linux/bitops.h>
12#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/interrupt.h>
15#include <linux/irqdomain.h>
16#include <linux/irqchip.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/mfd/syscon.h>
20#include <linux/regmap.h>
21
22/* The source ID bits start from 4 to 31 (total 28 bits)*/
23#define BIT_OFS			4
24#define KEYSTONE_N_IRQ		(32 - BIT_OFS)
25
26struct keystone_irq_device {
27	struct device		*dev;
28	struct irq_chip		 chip;
29	u32			 mask;
30	int			 irq;
31	struct irq_domain	*irqd;
32	struct regmap		*devctrl_regs;
33	u32			devctrl_offset;
34	raw_spinlock_t		wa_lock;
35};
36
37static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
38{
39	int ret;
40	u32 val = 0;
41
42	ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
43	if (ret < 0)
44		dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
45	return val;
46}
47
48static inline void
49keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
50{
51	int ret;
52
53	ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
54	if (ret < 0)
55		dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
56}
57
58static void keystone_irq_setmask(struct irq_data *d)
59{
60	struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
61
62	kirq->mask |= BIT(d->hwirq);
63	dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask);
64}
65
66static void keystone_irq_unmask(struct irq_data *d)
67{
68	struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
69
70	kirq->mask &= ~BIT(d->hwirq);
71	dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
72}
73
74static void keystone_irq_ack(struct irq_data *d)
75{
76	/* nothing to do here */
77}
78
79static irqreturn_t keystone_irq_handler(int irq, void *keystone_irq)
80{
81	struct keystone_irq_device *kirq = keystone_irq;
82	unsigned long wa_lock_flags;
83	unsigned long pending;
84	int src, err;
85
86	dev_dbg(kirq->dev, "start irq %d\n", irq);
87
88	pending = keystone_irq_readl(kirq);
89	keystone_irq_writel(kirq, pending);
90
91	dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
92
93	pending = (pending >> BIT_OFS) & ~kirq->mask;
94
95	dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
96
97	for (src = 0; src < KEYSTONE_N_IRQ; src++) {
98		if (BIT(src) & pending) {
99			raw_spin_lock_irqsave(&kirq->wa_lock, wa_lock_flags);
100			err = generic_handle_domain_irq(kirq->irqd, src);
101			raw_spin_unlock_irqrestore(&kirq->wa_lock,
102						   wa_lock_flags);
103
104			if (err)
105				dev_warn_ratelimited(kirq->dev, "spurious irq detected hwirq %d\n",
106						     src);
107		}
108	}
109
110	dev_dbg(kirq->dev, "end irq %d\n", irq);
111	return IRQ_HANDLED;
112}
113
114static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
115				irq_hw_number_t hw)
116{
117	struct keystone_irq_device *kirq = h->host_data;
118
119	irq_set_chip_data(virq, kirq);
120	irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
121	irq_set_probe(virq);
122	return 0;
123}
124
125static const struct irq_domain_ops keystone_irq_ops = {
126	.map	= keystone_irq_map,
127	.xlate	= irq_domain_xlate_onecell,
128};
129
130static int keystone_irq_probe(struct platform_device *pdev)
131{
132	struct device *dev = &pdev->dev;
133	struct device_node *np = dev->of_node;
134	struct keystone_irq_device *kirq;
135	int ret;
136
137	if (np == NULL)
138		return -EINVAL;
139
140	kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
141	if (!kirq)
142		return -ENOMEM;
143
144	kirq->devctrl_regs =
145		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
146	if (IS_ERR(kirq->devctrl_regs))
147		return PTR_ERR(kirq->devctrl_regs);
148
149	ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
150					 &kirq->devctrl_offset);
151	if (ret) {
152		dev_err(dev, "couldn't read the devctrl_offset offset!\n");
153		return ret;
154	}
155
156	kirq->irq = platform_get_irq(pdev, 0);
157	if (kirq->irq < 0)
158		return kirq->irq;
159
160	kirq->dev = dev;
161	kirq->mask = ~0x0;
162	kirq->chip.name		= "keystone-irq";
163	kirq->chip.irq_ack	= keystone_irq_ack;
164	kirq->chip.irq_mask	= keystone_irq_setmask;
165	kirq->chip.irq_unmask	= keystone_irq_unmask;
166
167	kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
168					   &keystone_irq_ops, kirq);
169	if (!kirq->irqd) {
170		dev_err(dev, "IRQ domain registration failed\n");
171		return -ENODEV;
172	}
173
174	raw_spin_lock_init(&kirq->wa_lock);
175
176	platform_set_drvdata(pdev, kirq);
177
178	ret = request_irq(kirq->irq, keystone_irq_handler,
179			  0, dev_name(dev), kirq);
180	if (ret) {
181		irq_domain_remove(kirq->irqd);
182		return ret;
183	}
184
185	/* clear all source bits */
186	keystone_irq_writel(kirq, ~0x0);
187
188	dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
189
190	return 0;
191}
192
193static void keystone_irq_remove(struct platform_device *pdev)
194{
195	struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
196	int hwirq;
197
198	free_irq(kirq->irq, kirq);
199
200	for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
201		irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
202
203	irq_domain_remove(kirq->irqd);
204}
205
206static const struct of_device_id keystone_irq_dt_ids[] = {
207	{ .compatible = "ti,keystone-irq", },
208	{},
209};
210MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
211
212static struct platform_driver keystone_irq_device_driver = {
213	.probe		= keystone_irq_probe,
214	.remove_new	= keystone_irq_remove,
215	.driver		= {
216		.name	= "keystone_irq",
217		.of_match_table	= of_match_ptr(keystone_irq_dt_ids),
218	}
219};
220
221module_platform_driver(keystone_irq_device_driver);
222
223MODULE_AUTHOR("Texas Instruments");
224MODULE_AUTHOR("Sajesh Kumar Saran");
225MODULE_AUTHOR("Grygorii Strashko");
226MODULE_DESCRIPTION("Keystone IRQ chip");
227MODULE_LICENSE("GPL v2");
228