1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Renesas IRQC Driver
  4 *
  5 *  Copyright (C) 2013 Magnus Damm
  6 */
  7
  8#include <linux/init.h>
  9#include <linux/platform_device.h>
 10#include <linux/interrupt.h>
 11#include <linux/ioport.h>
 12#include <linux/io.h>
 13#include <linux/irq.h>
 14#include <linux/irqdomain.h>
 15#include <linux/err.h>
 16#include <linux/slab.h>
 17#include <linux/module.h>
 18#include <linux/pm_runtime.h>
 19
 20#define IRQC_IRQ_MAX	32	/* maximum 32 interrupts per driver instance */
 21
 22#define IRQC_REQ_STS	0x00	/* Interrupt Request Status Register */
 23#define IRQC_EN_STS	0x04	/* Interrupt Enable Status Register */
 24#define IRQC_EN_SET	0x08	/* Interrupt Enable Set Register */
 25#define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
 26				/* SYS-CPU vs. RT-CPU */
 27#define DETECT_STATUS	0x100	/* IRQn Detect Status Register */
 28#define MONITOR		0x104	/* IRQn Signal Level Monitor Register */
 29#define HLVL_STS	0x108	/* IRQn High Level Detect Status Register */
 30#define LLVL_STS	0x10c	/* IRQn Low Level Detect Status Register */
 31#define S_R_EDGE_STS	0x110	/* IRQn Sync Rising Edge Detect Status Reg. */
 32#define S_F_EDGE_STS	0x114	/* IRQn Sync Falling Edge Detect Status Reg. */
 33#define A_R_EDGE_STS	0x118	/* IRQn Async Rising Edge Detect Status Reg. */
 34#define A_F_EDGE_STS	0x11c	/* IRQn Async Falling Edge Detect Status Reg. */
 35#define CHTEN_STS	0x120	/* Chattering Reduction Status Register */
 36#define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
 37				/* IRQn Configuration Register */
 38
 39struct irqc_irq {
 40	int hw_irq;
 41	int requested_irq;
 42	struct irqc_priv *p;
 43};
 44
 45struct irqc_priv {
 46	void __iomem *iomem;
 47	void __iomem *cpu_int_base;
 48	struct irqc_irq irq[IRQC_IRQ_MAX];
 49	unsigned int number_of_irqs;
 50	struct device *dev;
 51	struct irq_chip_generic *gc;
 52	struct irq_domain *irq_domain;
 53	atomic_t wakeup_path;
 54};
 55
 56static struct irqc_priv *irq_data_to_priv(struct irq_data *data)
 57{
 58	return data->domain->host_data;
 59}
 60
 61static void irqc_dbg(struct irqc_irq *i, char *str)
 62{
 63	dev_dbg(i->p->dev, "%s (%d:%d)\n", str, i->requested_irq, i->hw_irq);
 64}
 65
 66static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 67	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
 68	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
 69	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
 70	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
 71	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
 72};
 73
 74static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
 75{
 76	struct irqc_priv *p = irq_data_to_priv(d);
 77	int hw_irq = irqd_to_hwirq(d);
 78	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
 79	u32 tmp;
 80
 81	irqc_dbg(&p->irq[hw_irq], "sense");
 82
 83	if (!value)
 84		return -EINVAL;
 85
 86	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
 87	tmp &= ~0x3f;
 88	tmp |= value;
 89	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
 90	return 0;
 91}
 92
 93static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
 94{
 95	struct irqc_priv *p = irq_data_to_priv(d);
 96	int hw_irq = irqd_to_hwirq(d);
 97
 98	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
 99	if (on)
100		atomic_inc(&p->wakeup_path);
101	else
102		atomic_dec(&p->wakeup_path);
103
104	return 0;
105}
106
107static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
108{
109	struct irqc_irq *i = dev_id;
110	struct irqc_priv *p = i->p;
111	u32 bit = BIT(i->hw_irq);
112
113	irqc_dbg(i, "demux1");
114
115	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
116		iowrite32(bit, p->iomem + DETECT_STATUS);
117		irqc_dbg(i, "demux2");
118		generic_handle_domain_irq(p->irq_domain, i->hw_irq);
119		return IRQ_HANDLED;
120	}
121	return IRQ_NONE;
122}
123
124static int irqc_probe(struct platform_device *pdev)
125{
126	struct device *dev = &pdev->dev;
127	const char *name = dev_name(dev);
128	struct irqc_priv *p;
129	int ret;
130	int k;
131
132	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
133	if (!p)
134		return -ENOMEM;
135
136	p->dev = dev;
137	platform_set_drvdata(pdev, p);
138
139	pm_runtime_enable(dev);
140	pm_runtime_get_sync(dev);
141
142	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
143	for (k = 0; k < IRQC_IRQ_MAX; k++) {
144		ret = platform_get_irq_optional(pdev, k);
145		if (ret == -ENXIO)
146			break;
147		if (ret < 0)
148			goto err_runtime_pm_disable;
149
150		p->irq[k].p = p;
151		p->irq[k].hw_irq = k;
152		p->irq[k].requested_irq = ret;
153	}
154
155	p->number_of_irqs = k;
156	if (p->number_of_irqs < 1) {
157		dev_err(dev, "not enough IRQ resources\n");
158		ret = -EINVAL;
159		goto err_runtime_pm_disable;
160	}
161
162	/* ioremap IOMEM and setup read/write callbacks */
163	p->iomem = devm_platform_ioremap_resource(pdev, 0);
164	if (IS_ERR(p->iomem)) {
165		ret = PTR_ERR(p->iomem);
166		goto err_runtime_pm_disable;
167	}
168
169	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
170
171	p->irq_domain = irq_domain_add_linear(dev->of_node, p->number_of_irqs,
172					      &irq_generic_chip_ops, p);
173	if (!p->irq_domain) {
174		ret = -ENXIO;
175		dev_err(dev, "cannot initialize irq domain\n");
176		goto err_runtime_pm_disable;
177	}
178
179	ret = irq_alloc_domain_generic_chips(p->irq_domain, p->number_of_irqs,
180					     1, "irqc", handle_level_irq,
181					     0, 0, IRQ_GC_INIT_NESTED_LOCK);
182	if (ret) {
183		dev_err(dev, "cannot allocate generic chip\n");
184		goto err_remove_domain;
185	}
186
187	p->gc = irq_get_domain_generic_chip(p->irq_domain, 0);
188	p->gc->reg_base = p->cpu_int_base;
189	p->gc->chip_types[0].regs.enable = IRQC_EN_SET;
190	p->gc->chip_types[0].regs.disable = IRQC_EN_STS;
191	p->gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
192	p->gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
193	p->gc->chip_types[0].chip.irq_set_type	= irqc_irq_set_type;
194	p->gc->chip_types[0].chip.irq_set_wake	= irqc_irq_set_wake;
195	p->gc->chip_types[0].chip.flags	= IRQCHIP_MASK_ON_SUSPEND;
196
197	irq_domain_set_pm_device(p->irq_domain, dev);
198
199	/* request interrupts one by one */
200	for (k = 0; k < p->number_of_irqs; k++) {
201		if (devm_request_irq(dev, p->irq[k].requested_irq,
202				     irqc_irq_handler, 0, name, &p->irq[k])) {
203			dev_err(dev, "failed to request IRQ\n");
204			ret = -ENOENT;
205			goto err_remove_domain;
206		}
207	}
208
209	dev_info(dev, "driving %d irqs\n", p->number_of_irqs);
210
211	return 0;
212
213err_remove_domain:
214	irq_domain_remove(p->irq_domain);
215err_runtime_pm_disable:
216	pm_runtime_put(dev);
217	pm_runtime_disable(dev);
218	return ret;
219}
220
221static void irqc_remove(struct platform_device *pdev)
222{
223	struct irqc_priv *p = platform_get_drvdata(pdev);
224
225	irq_domain_remove(p->irq_domain);
226	pm_runtime_put(&pdev->dev);
227	pm_runtime_disable(&pdev->dev);
228}
229
230static int __maybe_unused irqc_suspend(struct device *dev)
231{
232	struct irqc_priv *p = dev_get_drvdata(dev);
233
234	if (atomic_read(&p->wakeup_path))
235		device_set_wakeup_path(dev);
236
237	return 0;
238}
239
240static SIMPLE_DEV_PM_OPS(irqc_pm_ops, irqc_suspend, NULL);
241
242static const struct of_device_id irqc_dt_ids[] = {
243	{ .compatible = "renesas,irqc", },
244	{},
245};
246MODULE_DEVICE_TABLE(of, irqc_dt_ids);
247
248static struct platform_driver irqc_device_driver = {
249	.probe		= irqc_probe,
250	.remove_new	= irqc_remove,
251	.driver		= {
252		.name		= "renesas_irqc",
253		.of_match_table	= irqc_dt_ids,
254		.pm		= &irqc_pm_ops,
255	}
256};
257
258static int __init irqc_init(void)
259{
260	return platform_driver_register(&irqc_device_driver);
261}
262postcore_initcall(irqc_init);
263
264static void __exit irqc_exit(void)
265{
266	platform_driver_unregister(&irqc_device_driver);
267}
268module_exit(irqc_exit);
269
270MODULE_AUTHOR("Magnus Damm");
271MODULE_DESCRIPTION("Renesas IRQC Driver");