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 
26 struct 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 
37 static 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 
48 static inline void
49 keystone_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 
58 static 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 
66 static 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 
74 static void keystone_irq_ack(struct irq_data *d)
75 {
76 	/* nothing to do here */
77 }
78 
79 static 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 
114 static 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 
125 static const struct irq_domain_ops keystone_irq_ops = {
126 	.map	= keystone_irq_map,
127 	.xlate	= irq_domain_xlate_onecell,
128 };
129 
130 static 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 
193 static int 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 	return 0;
205 }
206 
207 static const struct of_device_id keystone_irq_dt_ids[] = {
208 	{ .compatible = "ti,keystone-irq", },
209 	{},
210 };
211 MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
212 
213 static struct platform_driver keystone_irq_device_driver = {
214 	.probe		= keystone_irq_probe,
215 	.remove		= keystone_irq_remove,
216 	.driver		= {
217 		.name	= "keystone_irq",
218 		.of_match_table	= of_match_ptr(keystone_irq_dt_ids),
219 	}
220 };
221 
222 module_platform_driver(keystone_irq_device_driver);
223 
224 MODULE_AUTHOR("Texas Instruments");
225 MODULE_AUTHOR("Sajesh Kumar Saran");
226 MODULE_AUTHOR("Grygorii Strashko");
227 MODULE_DESCRIPTION("Keystone IRQ chip");
228 MODULE_LICENSE("GPL v2");
229