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/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/io.h>
26 #include <linux/irq.h>
27 #include <linux/irqdomain.h>
28 #include <linux/err.h>
29 #include <linux/slab.h>
30 #include <linux/module.h>
31 #include <linux/platform_data/irq-renesas-irqc.h>
32 
33 #define IRQC_IRQ_MAX 32 /* maximum 32 interrupts per driver instance */
34 
35 #define IRQC_REQ_STS 0x00
36 #define IRQC_EN_STS 0x04
37 #define IRQC_EN_SET 0x08
38 #define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
39 #define DETECT_STATUS 0x100
40 #define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
41 
42 struct irqc_irq {
43 	int hw_irq;
44 	int requested_irq;
45 	int domain_irq;
46 	struct irqc_priv *p;
47 };
48 
49 struct irqc_priv {
50 	void __iomem *iomem;
51 	void __iomem *cpu_int_base;
52 	struct irqc_irq irq[IRQC_IRQ_MAX];
53 	struct renesas_irqc_config config;
54 	unsigned int number_of_irqs;
55 	struct platform_device *pdev;
56 	struct irq_chip irq_chip;
57 	struct irq_domain *irq_domain;
58 };
59 
60 static void irqc_dbg(struct irqc_irq *i, char *str)
61 {
62 	dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
63 		str, i->requested_irq, i->hw_irq, i->domain_irq);
64 }
65 
66 static void irqc_irq_enable(struct irq_data *d)
67 {
68 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
69 	int hw_irq = irqd_to_hwirq(d);
70 
71 	irqc_dbg(&p->irq[hw_irq], "enable");
72 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_SET);
73 }
74 
75 static void irqc_irq_disable(struct irq_data *d)
76 {
77 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
78 	int hw_irq = irqd_to_hwirq(d);
79 
80 	irqc_dbg(&p->irq[hw_irq], "disable");
81 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_STS);
82 }
83 
84 static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
85 	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
86 	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
87 	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
88 	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
89 	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
90 };
91 
92 static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
93 {
94 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
95 	int hw_irq = irqd_to_hwirq(d);
96 	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
97 	unsigned long tmp;
98 
99 	irqc_dbg(&p->irq[hw_irq], "sense");
100 
101 	if (!value)
102 		return -EINVAL;
103 
104 	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
105 	tmp &= ~0x3f;
106 	tmp |= value;
107 	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
108 	return 0;
109 }
110 
111 static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
112 {
113 	struct irqc_irq *i = dev_id;
114 	struct irqc_priv *p = i->p;
115 	unsigned long bit = BIT(i->hw_irq);
116 
117 	irqc_dbg(i, "demux1");
118 
119 	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
120 		iowrite32(bit, p->iomem + DETECT_STATUS);
121 		irqc_dbg(i, "demux2");
122 		generic_handle_irq(i->domain_irq);
123 		return IRQ_HANDLED;
124 	}
125 	return IRQ_NONE;
126 }
127 
128 static int irqc_irq_domain_map(struct irq_domain *h, unsigned int virq,
129 			       irq_hw_number_t hw)
130 {
131 	struct irqc_priv *p = h->host_data;
132 
133 	p->irq[hw].domain_irq = virq;
134 	p->irq[hw].hw_irq = hw;
135 
136 	irqc_dbg(&p->irq[hw], "map");
137 	irq_set_chip_data(virq, h->host_data);
138 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
139 	set_irq_flags(virq, IRQF_VALID); /* kill me now */
140 	return 0;
141 }
142 
143 static struct irq_domain_ops irqc_irq_domain_ops = {
144 	.map	= irqc_irq_domain_map,
145 	.xlate  = irq_domain_xlate_twocell,
146 };
147 
148 static int irqc_probe(struct platform_device *pdev)
149 {
150 	struct renesas_irqc_config *pdata = pdev->dev.platform_data;
151 	struct irqc_priv *p;
152 	struct resource *io;
153 	struct resource *irq;
154 	struct irq_chip *irq_chip;
155 	const char *name = dev_name(&pdev->dev);
156 	int ret;
157 	int k;
158 
159 	p = kzalloc(sizeof(*p), GFP_KERNEL);
160 	if (!p) {
161 		dev_err(&pdev->dev, "failed to allocate driver data\n");
162 		ret = -ENOMEM;
163 		goto err0;
164 	}
165 
166 	/* deal with driver instance configuration */
167 	if (pdata)
168 		memcpy(&p->config, pdata, sizeof(*pdata));
169 
170 	p->pdev = pdev;
171 	platform_set_drvdata(pdev, p);
172 
173 	/* get hold of manadatory IOMEM */
174 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
175 	if (!io) {
176 		dev_err(&pdev->dev, "not enough IOMEM resources\n");
177 		ret = -EINVAL;
178 		goto err1;
179 	}
180 
181 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
182 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
183 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
184 		if (!irq)
185 			break;
186 
187 		p->irq[k].p = p;
188 		p->irq[k].requested_irq = irq->start;
189 	}
190 
191 	p->number_of_irqs = k;
192 	if (p->number_of_irqs < 1) {
193 		dev_err(&pdev->dev, "not enough IRQ resources\n");
194 		ret = -EINVAL;
195 		goto err1;
196 	}
197 
198 	/* ioremap IOMEM and setup read/write callbacks */
199 	p->iomem = ioremap_nocache(io->start, resource_size(io));
200 	if (!p->iomem) {
201 		dev_err(&pdev->dev, "failed to remap IOMEM\n");
202 		ret = -ENXIO;
203 		goto err2;
204 	}
205 
206 	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
207 
208 	irq_chip = &p->irq_chip;
209 	irq_chip->name = name;
210 	irq_chip->irq_mask = irqc_irq_disable;
211 	irq_chip->irq_unmask = irqc_irq_enable;
212 	irq_chip->irq_set_type = irqc_irq_set_type;
213 	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
214 
215 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
216 					      p->number_of_irqs,
217 					      p->config.irq_base,
218 					      &irqc_irq_domain_ops, p);
219 	if (!p->irq_domain) {
220 		ret = -ENXIO;
221 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
222 		goto err2;
223 	}
224 
225 	/* request interrupts one by one */
226 	for (k = 0; k < p->number_of_irqs; k++) {
227 		if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
228 				0, name, &p->irq[k])) {
229 			dev_err(&pdev->dev, "failed to request IRQ\n");
230 			ret = -ENOENT;
231 			goto err3;
232 		}
233 	}
234 
235 	dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
236 
237 	/* warn in case of mismatch if irq base is specified */
238 	if (p->config.irq_base) {
239 		if (p->config.irq_base != p->irq[0].domain_irq)
240 			dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
241 				 p->config.irq_base, p->irq[0].domain_irq);
242 	}
243 
244 	return 0;
245 err3:
246 	while (--k >= 0)
247 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
248 
249 	irq_domain_remove(p->irq_domain);
250 err2:
251 	iounmap(p->iomem);
252 err1:
253 	kfree(p);
254 err0:
255 	return ret;
256 }
257 
258 static int irqc_remove(struct platform_device *pdev)
259 {
260 	struct irqc_priv *p = platform_get_drvdata(pdev);
261 	int k;
262 
263 	for (k = 0; k < p->number_of_irqs; k++)
264 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
265 
266 	irq_domain_remove(p->irq_domain);
267 	iounmap(p->iomem);
268 	kfree(p);
269 	return 0;
270 }
271 
272 static const struct of_device_id irqc_dt_ids[] = {
273 	{ .compatible = "renesas,irqc", },
274 	{},
275 };
276 MODULE_DEVICE_TABLE(of, irqc_dt_ids);
277 
278 static struct platform_driver irqc_device_driver = {
279 	.probe		= irqc_probe,
280 	.remove		= irqc_remove,
281 	.driver		= {
282 		.name	= "renesas_irqc",
283 		.of_match_table	= irqc_dt_ids,
284 	}
285 };
286 
287 static int __init irqc_init(void)
288 {
289 	return platform_driver_register(&irqc_device_driver);
290 }
291 postcore_initcall(irqc_init);
292 
293 static void __exit irqc_exit(void)
294 {
295 	platform_driver_unregister(&irqc_device_driver);
296 }
297 module_exit(irqc_exit);
298 
299 MODULE_AUTHOR("Magnus Damm");
300 MODULE_DESCRIPTION("Renesas IRQC Driver");
301 MODULE_LICENSE("GPL v2");
302