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/irqdomain.h>
23#include <linux/irqchip/chained_irq.h>
24#include <linux/of.h>
25#include <linux/of_platform.h>
26#include <linux/mfd/syscon.h>
27#include <linux/regmap.h>
28#include "irqchip.h"
29
30
31/* The source ID bits start from 4 to 31 (total 28 bits)*/
32#define BIT_OFS			4
33#define KEYSTONE_N_IRQ		(32 - BIT_OFS)
34
35struct keystone_irq_device {
36	struct device		*dev;
37	struct irq_chip		 chip;
38	u32			 mask;
39	int			 irq;
40	struct irq_domain	*irqd;
41	struct regmap		*devctrl_regs;
42	u32			devctrl_offset;
43};
44
45static 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
56static inline void
57keystone_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
66static 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
74static 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
82static void keystone_irq_ack(struct irq_data *d)
83{
84	/* nothing to do here */
85}
86
87static void keystone_irq_handler(unsigned irq, struct irq_desc *desc)
88{
89	struct keystone_irq_device *kirq = irq_desc_get_handler_data(desc);
90	unsigned long pending;
91	int src, virq;
92
93	dev_dbg(kirq->dev, "start irq %d\n", irq);
94
95	chained_irq_enter(irq_desc_get_chip(desc), desc);
96
97	pending = keystone_irq_readl(kirq);
98	keystone_irq_writel(kirq, pending);
99
100	dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
101
102	pending = (pending >> BIT_OFS) & ~kirq->mask;
103
104	dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
105
106	for (src = 0; src < KEYSTONE_N_IRQ; src++) {
107		if (BIT(src) & pending) {
108			virq = irq_find_mapping(kirq->irqd, src);
109			dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
110				src, virq);
111			if (!virq)
112				dev_warn(kirq->dev, "sporious irq detected hwirq %d, virq %d\n",
113					 src, virq);
114			generic_handle_irq(virq);
115		}
116	}
117
118	chained_irq_exit(irq_desc_get_chip(desc), desc);
119
120	dev_dbg(kirq->dev, "end irq %d\n", irq);
121}
122
123static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
124				irq_hw_number_t hw)
125{
126	struct keystone_irq_device *kirq = h->host_data;
127
128	irq_set_chip_data(virq, kirq);
129	irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
130	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
131	return 0;
132}
133
134static struct irq_domain_ops keystone_irq_ops = {
135	.map	= keystone_irq_map,
136	.xlate	= irq_domain_xlate_onecell,
137};
138
139static int keystone_irq_probe(struct platform_device *pdev)
140{
141	struct device *dev = &pdev->dev;
142	struct device_node *np = dev->of_node;
143	struct keystone_irq_device *kirq;
144	int ret;
145
146	if (np == NULL)
147		return -EINVAL;
148
149	kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
150	if (!kirq)
151		return -ENOMEM;
152
153	kirq->devctrl_regs =
154		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
155	if (IS_ERR(kirq->devctrl_regs))
156		return PTR_ERR(kirq->devctrl_regs);
157
158	ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
159					 &kirq->devctrl_offset);
160	if (ret) {
161		dev_err(dev, "couldn't read the devctrl_offset offset!\n");
162		return ret;
163	}
164
165	kirq->irq = platform_get_irq(pdev, 0);
166	if (kirq->irq < 0) {
167		dev_err(dev, "no irq resource %d\n", kirq->irq);
168		return kirq->irq;
169	}
170
171	kirq->dev = dev;
172	kirq->mask = ~0x0;
173	kirq->chip.name		= "keystone-irq";
174	kirq->chip.irq_ack	= keystone_irq_ack;
175	kirq->chip.irq_mask	= keystone_irq_setmask;
176	kirq->chip.irq_unmask	= keystone_irq_unmask;
177
178	kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
179					   &keystone_irq_ops, kirq);
180	if (!kirq->irqd) {
181		dev_err(dev, "IRQ domain registration failed\n");
182		return -ENODEV;
183	}
184
185	platform_set_drvdata(pdev, kirq);
186
187	irq_set_chained_handler(kirq->irq, keystone_irq_handler);
188	irq_set_handler_data(kirq->irq, kirq);
189
190	/* clear all source bits */
191	keystone_irq_writel(kirq, ~0x0);
192
193	dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
194
195	return 0;
196}
197
198static int keystone_irq_remove(struct platform_device *pdev)
199{
200	struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
201	int hwirq;
202
203	for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
204		irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
205
206	irq_domain_remove(kirq->irqd);
207	return 0;
208}
209
210static const struct of_device_id keystone_irq_dt_ids[] = {
211	{ .compatible = "ti,keystone-irq", },
212	{},
213};
214MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
215
216static struct platform_driver keystone_irq_device_driver = {
217	.probe		= keystone_irq_probe,
218	.remove		= keystone_irq_remove,
219	.driver		= {
220		.name	= "keystone_irq",
221		.of_match_table	= of_match_ptr(keystone_irq_dt_ids),
222	}
223};
224
225module_platform_driver(keystone_irq_device_driver);
226
227MODULE_AUTHOR("Texas Instruments");
228MODULE_AUTHOR("Sajesh Kumar Saran");
229MODULE_AUTHOR("Grygorii Strashko");
230MODULE_DESCRIPTION("Keystone IRQ chip");
231MODULE_LICENSE("GPL v2");
232