1 /*
2  * Renesas IRQC Driver
3  *
4  *  Copyright (C) 2013 Magnus Damm
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 #include <linux/clk.h>
21 #include <linux/init.h>
22 #include <linux/platform_device.h>
23 #include <linux/spinlock.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/io.h>
27 #include <linux/irq.h>
28 #include <linux/irqdomain.h>
29 #include <linux/err.h>
30 #include <linux/slab.h>
31 #include <linux/module.h>
32 #include <linux/pm_runtime.h>
33 
34 #define IRQC_IRQ_MAX	32	/* maximum 32 interrupts per driver instance */
35 
36 #define IRQC_REQ_STS	0x00	/* Interrupt Request Status Register */
37 #define IRQC_EN_STS	0x04	/* Interrupt Enable Status Register */
38 #define IRQC_EN_SET	0x08	/* Interrupt Enable Set Register */
39 #define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
40 				/* SYS-CPU vs. RT-CPU */
41 #define DETECT_STATUS	0x100	/* IRQn Detect Status Register */
42 #define MONITOR		0x104	/* IRQn Signal Level Monitor Register */
43 #define HLVL_STS	0x108	/* IRQn High Level Detect Status Register */
44 #define LLVL_STS	0x10c	/* IRQn Low Level Detect Status Register */
45 #define S_R_EDGE_STS	0x110	/* IRQn Sync Rising Edge Detect Status Reg. */
46 #define S_F_EDGE_STS	0x114	/* IRQn Sync Falling Edge Detect Status Reg. */
47 #define A_R_EDGE_STS	0x118	/* IRQn Async Rising Edge Detect Status Reg. */
48 #define A_F_EDGE_STS	0x11c	/* IRQn Async Falling Edge Detect Status Reg. */
49 #define CHTEN_STS	0x120	/* Chattering Reduction Status Register */
50 #define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
51 				/* IRQn Configuration Register */
52 
53 struct irqc_irq {
54 	int hw_irq;
55 	int requested_irq;
56 	struct irqc_priv *p;
57 };
58 
59 struct irqc_priv {
60 	void __iomem *iomem;
61 	void __iomem *cpu_int_base;
62 	struct irqc_irq irq[IRQC_IRQ_MAX];
63 	unsigned int number_of_irqs;
64 	struct platform_device *pdev;
65 	struct irq_chip_generic *gc;
66 	struct irq_domain *irq_domain;
67 	struct clk *clk;
68 };
69 
70 static struct irqc_priv *irq_data_to_priv(struct irq_data *data)
71 {
72 	return data->domain->host_data;
73 }
74 
75 static void irqc_dbg(struct irqc_irq *i, char *str)
76 {
77 	dev_dbg(&i->p->pdev->dev, "%s (%d:%d)\n",
78 		str, i->requested_irq, i->hw_irq);
79 }
80 
81 static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
82 	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
83 	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
84 	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
85 	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
86 	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
87 };
88 
89 static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
90 {
91 	struct irqc_priv *p = irq_data_to_priv(d);
92 	int hw_irq = irqd_to_hwirq(d);
93 	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
94 	u32 tmp;
95 
96 	irqc_dbg(&p->irq[hw_irq], "sense");
97 
98 	if (!value)
99 		return -EINVAL;
100 
101 	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
102 	tmp &= ~0x3f;
103 	tmp |= value;
104 	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
105 	return 0;
106 }
107 
108 static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
109 {
110 	struct irqc_priv *p = irq_data_to_priv(d);
111 	int hw_irq = irqd_to_hwirq(d);
112 
113 	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
114 
115 	if (!p->clk)
116 		return 0;
117 
118 	if (on)
119 		clk_enable(p->clk);
120 	else
121 		clk_disable(p->clk);
122 
123 	return 0;
124 }
125 
126 static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
127 {
128 	struct irqc_irq *i = dev_id;
129 	struct irqc_priv *p = i->p;
130 	u32 bit = BIT(i->hw_irq);
131 
132 	irqc_dbg(i, "demux1");
133 
134 	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
135 		iowrite32(bit, p->iomem + DETECT_STATUS);
136 		irqc_dbg(i, "demux2");
137 		generic_handle_irq(irq_find_mapping(p->irq_domain, i->hw_irq));
138 		return IRQ_HANDLED;
139 	}
140 	return IRQ_NONE;
141 }
142 
143 static int irqc_probe(struct platform_device *pdev)
144 {
145 	struct irqc_priv *p;
146 	struct resource *io;
147 	struct resource *irq;
148 	const char *name = dev_name(&pdev->dev);
149 	int ret;
150 	int k;
151 
152 	p = kzalloc(sizeof(*p), GFP_KERNEL);
153 	if (!p) {
154 		dev_err(&pdev->dev, "failed to allocate driver data\n");
155 		ret = -ENOMEM;
156 		goto err0;
157 	}
158 
159 	p->pdev = pdev;
160 	platform_set_drvdata(pdev, p);
161 
162 	p->clk = devm_clk_get(&pdev->dev, NULL);
163 	if (IS_ERR(p->clk)) {
164 		dev_warn(&pdev->dev, "unable to get clock\n");
165 		p->clk = NULL;
166 	}
167 
168 	pm_runtime_enable(&pdev->dev);
169 	pm_runtime_get_sync(&pdev->dev);
170 
171 	/* get hold of manadatory IOMEM */
172 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
173 	if (!io) {
174 		dev_err(&pdev->dev, "not enough IOMEM resources\n");
175 		ret = -EINVAL;
176 		goto err1;
177 	}
178 
179 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
180 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
181 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
182 		if (!irq)
183 			break;
184 
185 		p->irq[k].p = p;
186 		p->irq[k].hw_irq = k;
187 		p->irq[k].requested_irq = irq->start;
188 	}
189 
190 	p->number_of_irqs = k;
191 	if (p->number_of_irqs < 1) {
192 		dev_err(&pdev->dev, "not enough IRQ resources\n");
193 		ret = -EINVAL;
194 		goto err1;
195 	}
196 
197 	/* ioremap IOMEM and setup read/write callbacks */
198 	p->iomem = ioremap_nocache(io->start, resource_size(io));
199 	if (!p->iomem) {
200 		dev_err(&pdev->dev, "failed to remap IOMEM\n");
201 		ret = -ENXIO;
202 		goto err2;
203 	}
204 
205 	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
206 
207 	p->irq_domain = irq_domain_add_linear(pdev->dev.of_node,
208 					      p->number_of_irqs,
209 					      &irq_generic_chip_ops, p);
210 	if (!p->irq_domain) {
211 		ret = -ENXIO;
212 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
213 		goto err2;
214 	}
215 
216 	ret = irq_alloc_domain_generic_chips(p->irq_domain, p->number_of_irqs,
217 					     1, name, handle_level_irq,
218 					     0, 0, IRQ_GC_INIT_NESTED_LOCK);
219 	if (ret) {
220 		dev_err(&pdev->dev, "cannot allocate generic chip\n");
221 		goto err3;
222 	}
223 
224 	p->gc = irq_get_domain_generic_chip(p->irq_domain, 0);
225 	p->gc->reg_base = p->cpu_int_base;
226 	p->gc->chip_types[0].regs.enable = IRQC_EN_SET;
227 	p->gc->chip_types[0].regs.disable = IRQC_EN_STS;
228 	p->gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
229 	p->gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
230 	p->gc->chip_types[0].chip.irq_set_type	= irqc_irq_set_type;
231 	p->gc->chip_types[0].chip.irq_set_wake	= irqc_irq_set_wake;
232 	p->gc->chip_types[0].chip.flags	= IRQCHIP_MASK_ON_SUSPEND;
233 
234 	/* request interrupts one by one */
235 	for (k = 0; k < p->number_of_irqs; k++) {
236 		if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
237 				0, name, &p->irq[k])) {
238 			dev_err(&pdev->dev, "failed to request IRQ\n");
239 			ret = -ENOENT;
240 			goto err4;
241 		}
242 	}
243 
244 	dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
245 
246 	return 0;
247 err4:
248 	while (--k >= 0)
249 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
250 
251 err3:
252 	irq_domain_remove(p->irq_domain);
253 err2:
254 	iounmap(p->iomem);
255 err1:
256 	pm_runtime_put(&pdev->dev);
257 	pm_runtime_disable(&pdev->dev);
258 	kfree(p);
259 err0:
260 	return ret;
261 }
262 
263 static int irqc_remove(struct platform_device *pdev)
264 {
265 	struct irqc_priv *p = platform_get_drvdata(pdev);
266 	int k;
267 
268 	for (k = 0; k < p->number_of_irqs; k++)
269 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
270 
271 	irq_domain_remove(p->irq_domain);
272 	iounmap(p->iomem);
273 	pm_runtime_put(&pdev->dev);
274 	pm_runtime_disable(&pdev->dev);
275 	kfree(p);
276 	return 0;
277 }
278 
279 static const struct of_device_id irqc_dt_ids[] = {
280 	{ .compatible = "renesas,irqc", },
281 	{},
282 };
283 MODULE_DEVICE_TABLE(of, irqc_dt_ids);
284 
285 static struct platform_driver irqc_device_driver = {
286 	.probe		= irqc_probe,
287 	.remove		= irqc_remove,
288 	.driver		= {
289 		.name	= "renesas_irqc",
290 		.of_match_table	= irqc_dt_ids,
291 	}
292 };
293 
294 static int __init irqc_init(void)
295 {
296 	return platform_driver_register(&irqc_device_driver);
297 }
298 postcore_initcall(irqc_init);
299 
300 static void __exit irqc_exit(void)
301 {
302 	platform_driver_unregister(&irqc_device_driver);
303 }
304 module_exit(irqc_exit);
305 
306 MODULE_AUTHOR("Magnus Damm");
307 MODULE_DESCRIPTION("Renesas IRQC Driver");
308 MODULE_LICENSE("GPL v2");
309