1 /*
2 * Texas Instruments Keystone IRQ controller IP driver
3 *
4 * Copyright (C) 2014 Texas Instruments, Inc.
5 * Author: Sajesh Kumar Saran <sajesh@ti.com>
6 * Grygorii Strashko <grygorii.strashko@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation version 2.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18 #include <linux/irq.h>
19 #include <linux/bitops.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/interrupt.h>
23 #include <linux/irqdomain.h>
24 #include <linux/irqchip.h>
25 #include <linux/of.h>
26 #include <linux/of_platform.h>
27 #include <linux/mfd/syscon.h>
28 #include <linux/regmap.h>
29
30 /* The source ID bits start from 4 to 31 (total 28 bits)*/
31 #define BIT_OFS 4
32 #define KEYSTONE_N_IRQ (32 - BIT_OFS)
33
34 struct keystone_irq_device {
35 struct device *dev;
36 struct irq_chip chip;
37 u32 mask;
38 int irq;
39 struct irq_domain *irqd;
40 struct regmap *devctrl_regs;
41 u32 devctrl_offset;
42 raw_spinlock_t wa_lock;
43 };
44
keystone_irq_readl(struct keystone_irq_device * kirq)45 static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
46 {
47 int ret;
48 u32 val = 0;
49
50 ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
51 if (ret < 0)
52 dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
53 return val;
54 }
55
56 static inline void
keystone_irq_writel(struct keystone_irq_device * kirq,u32 value)57 keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
58 {
59 int ret;
60
61 ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
62 if (ret < 0)
63 dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
64 }
65
keystone_irq_setmask(struct irq_data * d)66 static void keystone_irq_setmask(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, "mask %lu [%x]\n", d->hwirq, kirq->mask);
72 }
73
keystone_irq_unmask(struct irq_data * d)74 static void keystone_irq_unmask(struct irq_data *d)
75 {
76 struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
77
78 kirq->mask &= ~BIT(d->hwirq);
79 dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
80 }
81
keystone_irq_ack(struct irq_data * d)82 static void keystone_irq_ack(struct irq_data *d)
83 {
84 /* nothing to do here */
85 }
86
keystone_irq_handler(int irq,void * keystone_irq)87 static irqreturn_t keystone_irq_handler(int irq, void *keystone_irq)
88 {
89 struct keystone_irq_device *kirq = keystone_irq;
90 unsigned long wa_lock_flags;
91 unsigned long pending;
92 int src, virq;
93
94 dev_dbg(kirq->dev, "start irq %d\n", irq);
95
96 pending = keystone_irq_readl(kirq);
97 keystone_irq_writel(kirq, pending);
98
99 dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
100
101 pending = (pending >> BIT_OFS) & ~kirq->mask;
102
103 dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
104
105 for (src = 0; src < KEYSTONE_N_IRQ; src++) {
106 if (BIT(src) & pending) {
107 virq = irq_find_mapping(kirq->irqd, src);
108 dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
109 src, virq);
110 if (!virq)
111 dev_warn(kirq->dev, "spurious irq detected hwirq %d, virq %d\n",
112 src, virq);
113 raw_spin_lock_irqsave(&kirq->wa_lock, wa_lock_flags);
114 generic_handle_irq(virq);
115 raw_spin_unlock_irqrestore(&kirq->wa_lock,
116 wa_lock_flags);
117 }
118 }
119
120 dev_dbg(kirq->dev, "end irq %d\n", irq);
121 return IRQ_HANDLED;
122 }
123
keystone_irq_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)124 static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
125 irq_hw_number_t hw)
126 {
127 struct keystone_irq_device *kirq = h->host_data;
128
129 irq_set_chip_data(virq, kirq);
130 irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
131 irq_set_probe(virq);
132 return 0;
133 }
134
135 static const struct irq_domain_ops keystone_irq_ops = {
136 .map = keystone_irq_map,
137 .xlate = irq_domain_xlate_onecell,
138 };
139
keystone_irq_probe(struct platform_device * pdev)140 static int keystone_irq_probe(struct platform_device *pdev)
141 {
142 struct device *dev = &pdev->dev;
143 struct device_node *np = dev->of_node;
144 struct keystone_irq_device *kirq;
145 int ret;
146
147 if (np == NULL)
148 return -EINVAL;
149
150 kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
151 if (!kirq)
152 return -ENOMEM;
153
154 kirq->devctrl_regs =
155 syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
156 if (IS_ERR(kirq->devctrl_regs))
157 return PTR_ERR(kirq->devctrl_regs);
158
159 ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
160 &kirq->devctrl_offset);
161 if (ret) {
162 dev_err(dev, "couldn't read the devctrl_offset offset!\n");
163 return ret;
164 }
165
166 kirq->irq = platform_get_irq(pdev, 0);
167 if (kirq->irq < 0) {
168 dev_err(dev, "no irq resource %d\n", kirq->irq);
169 return kirq->irq;
170 }
171
172 kirq->dev = dev;
173 kirq->mask = ~0x0;
174 kirq->chip.name = "keystone-irq";
175 kirq->chip.irq_ack = keystone_irq_ack;
176 kirq->chip.irq_mask = keystone_irq_setmask;
177 kirq->chip.irq_unmask = keystone_irq_unmask;
178
179 kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
180 &keystone_irq_ops, kirq);
181 if (!kirq->irqd) {
182 dev_err(dev, "IRQ domain registration failed\n");
183 return -ENODEV;
184 }
185
186 raw_spin_lock_init(&kirq->wa_lock);
187
188 platform_set_drvdata(pdev, kirq);
189
190 ret = request_irq(kirq->irq, keystone_irq_handler,
191 0, dev_name(dev), kirq);
192 if (ret) {
193 irq_domain_remove(kirq->irqd);
194 return ret;
195 }
196
197 /* clear all source bits */
198 keystone_irq_writel(kirq, ~0x0);
199
200 dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
201
202 return 0;
203 }
204
keystone_irq_remove(struct platform_device * pdev)205 static int keystone_irq_remove(struct platform_device *pdev)
206 {
207 struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
208 int hwirq;
209
210 free_irq(kirq->irq, kirq);
211
212 for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
213 irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
214
215 irq_domain_remove(kirq->irqd);
216 return 0;
217 }
218
219 static const struct of_device_id keystone_irq_dt_ids[] = {
220 { .compatible = "ti,keystone-irq", },
221 {},
222 };
223 MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
224
225 static struct platform_driver keystone_irq_device_driver = {
226 .probe = keystone_irq_probe,
227 .remove = keystone_irq_remove,
228 .driver = {
229 .name = "keystone_irq",
230 .of_match_table = of_match_ptr(keystone_irq_dt_ids),
231 }
232 };
233
234 module_platform_driver(keystone_irq_device_driver);
235
236 MODULE_AUTHOR("Texas Instruments");
237 MODULE_AUTHOR("Sajesh Kumar Saran");
238 MODULE_AUTHOR("Grygorii Strashko");
239 MODULE_DESCRIPTION("Keystone IRQ chip");
240 MODULE_LICENSE("GPL v2");
241