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
 34struct 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
 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 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
124static 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
135static const struct irq_domain_ops keystone_irq_ops = {
136	.map	= keystone_irq_map,
137	.xlate	= irq_domain_xlate_onecell,
138};
139
140static 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		return kirq->irq;
169
170	kirq->dev = dev;
171	kirq->mask = ~0x0;
172	kirq->chip.name		= "keystone-irq";
173	kirq->chip.irq_ack	= keystone_irq_ack;
174	kirq->chip.irq_mask	= keystone_irq_setmask;
175	kirq->chip.irq_unmask	= keystone_irq_unmask;
176
177	kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
178					   &keystone_irq_ops, kirq);
179	if (!kirq->irqd) {
180		dev_err(dev, "IRQ domain registration failed\n");
181		return -ENODEV;
182	}
183
184	raw_spin_lock_init(&kirq->wa_lock);
185
186	platform_set_drvdata(pdev, kirq);
187
188	ret = request_irq(kirq->irq, keystone_irq_handler,
189			  0, dev_name(dev), kirq);
190	if (ret) {
191		irq_domain_remove(kirq->irqd);
192		return ret;
193	}
194
195	/* clear all source bits */
196	keystone_irq_writel(kirq, ~0x0);
197
198	dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
199
200	return 0;
201}
202
203static int keystone_irq_remove(struct platform_device *pdev)
204{
205	struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
206	int hwirq;
207
208	free_irq(kirq->irq, kirq);
209
210	for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
211		irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
212
213	irq_domain_remove(kirq->irqd);
214	return 0;
215}
216
217static const struct of_device_id keystone_irq_dt_ids[] = {
218	{ .compatible = "ti,keystone-irq", },
219	{},
220};
221MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
222
223static struct platform_driver keystone_irq_device_driver = {
224	.probe		= keystone_irq_probe,
225	.remove		= keystone_irq_remove,
226	.driver		= {
227		.name	= "keystone_irq",
228		.of_match_table	= of_match_ptr(keystone_irq_dt_ids),
229	}
230};
231
232module_platform_driver(keystone_irq_device_driver);
233
234MODULE_AUTHOR("Texas Instruments");
235MODULE_AUTHOR("Sajesh Kumar Saran");
236MODULE_AUTHOR("Grygorii Strashko");
237MODULE_DESCRIPTION("Keystone IRQ chip");
238MODULE_LICENSE("GPL v2");