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 	int domain_irq;
57 	struct irqc_priv *p;
58 };
59 
60 struct irqc_priv {
61 	void __iomem *iomem;
62 	void __iomem *cpu_int_base;
63 	struct irqc_irq irq[IRQC_IRQ_MAX];
64 	unsigned int number_of_irqs;
65 	struct platform_device *pdev;
66 	struct irq_chip irq_chip;
67 	struct irq_domain *irq_domain;
68 	struct clk *clk;
69 };
70 
71 static void irqc_dbg(struct irqc_irq *i, char *str)
72 {
73 	dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
74 		str, i->requested_irq, i->hw_irq, i->domain_irq);
75 }
76 
77 static void irqc_irq_enable(struct irq_data *d)
78 {
79 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
80 	int hw_irq = irqd_to_hwirq(d);
81 
82 	irqc_dbg(&p->irq[hw_irq], "enable");
83 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_SET);
84 }
85 
86 static void irqc_irq_disable(struct irq_data *d)
87 {
88 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
89 	int hw_irq = irqd_to_hwirq(d);
90 
91 	irqc_dbg(&p->irq[hw_irq], "disable");
92 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_STS);
93 }
94 
95 static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
96 	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
97 	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
98 	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
99 	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
100 	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
101 };
102 
103 static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
104 {
105 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
106 	int hw_irq = irqd_to_hwirq(d);
107 	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
108 	u32 tmp;
109 
110 	irqc_dbg(&p->irq[hw_irq], "sense");
111 
112 	if (!value)
113 		return -EINVAL;
114 
115 	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
116 	tmp &= ~0x3f;
117 	tmp |= value;
118 	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
119 	return 0;
120 }
121 
122 static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
123 {
124 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
125 
126 	if (!p->clk)
127 		return 0;
128 
129 	if (on)
130 		clk_enable(p->clk);
131 	else
132 		clk_disable(p->clk);
133 
134 	return 0;
135 }
136 
137 static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
138 {
139 	struct irqc_irq *i = dev_id;
140 	struct irqc_priv *p = i->p;
141 	u32 bit = BIT(i->hw_irq);
142 
143 	irqc_dbg(i, "demux1");
144 
145 	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
146 		iowrite32(bit, p->iomem + DETECT_STATUS);
147 		irqc_dbg(i, "demux2");
148 		generic_handle_irq(i->domain_irq);
149 		return IRQ_HANDLED;
150 	}
151 	return IRQ_NONE;
152 }
153 
154 static int irqc_irq_domain_map(struct irq_domain *h, unsigned int virq,
155 			       irq_hw_number_t hw)
156 {
157 	struct irqc_priv *p = h->host_data;
158 
159 	p->irq[hw].domain_irq = virq;
160 	p->irq[hw].hw_irq = hw;
161 
162 	irqc_dbg(&p->irq[hw], "map");
163 	irq_set_chip_data(virq, h->host_data);
164 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
165 	set_irq_flags(virq, IRQF_VALID); /* kill me now */
166 	return 0;
167 }
168 
169 static const struct irq_domain_ops irqc_irq_domain_ops = {
170 	.map	= irqc_irq_domain_map,
171 	.xlate  = irq_domain_xlate_twocell,
172 };
173 
174 static int irqc_probe(struct platform_device *pdev)
175 {
176 	struct irqc_priv *p;
177 	struct resource *io;
178 	struct resource *irq;
179 	struct irq_chip *irq_chip;
180 	const char *name = dev_name(&pdev->dev);
181 	int ret;
182 	int k;
183 
184 	p = kzalloc(sizeof(*p), GFP_KERNEL);
185 	if (!p) {
186 		dev_err(&pdev->dev, "failed to allocate driver data\n");
187 		ret = -ENOMEM;
188 		goto err0;
189 	}
190 
191 	p->pdev = pdev;
192 	platform_set_drvdata(pdev, p);
193 
194 	p->clk = devm_clk_get(&pdev->dev, NULL);
195 	if (IS_ERR(p->clk)) {
196 		dev_warn(&pdev->dev, "unable to get clock\n");
197 		p->clk = NULL;
198 	}
199 
200 	pm_runtime_enable(&pdev->dev);
201 	pm_runtime_get_sync(&pdev->dev);
202 
203 	/* get hold of manadatory IOMEM */
204 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
205 	if (!io) {
206 		dev_err(&pdev->dev, "not enough IOMEM resources\n");
207 		ret = -EINVAL;
208 		goto err1;
209 	}
210 
211 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
212 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
213 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
214 		if (!irq)
215 			break;
216 
217 		p->irq[k].p = p;
218 		p->irq[k].requested_irq = irq->start;
219 	}
220 
221 	p->number_of_irqs = k;
222 	if (p->number_of_irqs < 1) {
223 		dev_err(&pdev->dev, "not enough IRQ resources\n");
224 		ret = -EINVAL;
225 		goto err1;
226 	}
227 
228 	/* ioremap IOMEM and setup read/write callbacks */
229 	p->iomem = ioremap_nocache(io->start, resource_size(io));
230 	if (!p->iomem) {
231 		dev_err(&pdev->dev, "failed to remap IOMEM\n");
232 		ret = -ENXIO;
233 		goto err2;
234 	}
235 
236 	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
237 
238 	irq_chip = &p->irq_chip;
239 	irq_chip->name = name;
240 	irq_chip->irq_mask = irqc_irq_disable;
241 	irq_chip->irq_unmask = irqc_irq_enable;
242 	irq_chip->irq_set_type = irqc_irq_set_type;
243 	irq_chip->irq_set_wake = irqc_irq_set_wake;
244 	irq_chip->flags	= IRQCHIP_MASK_ON_SUSPEND;
245 
246 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
247 					      p->number_of_irqs, 0,
248 					      &irqc_irq_domain_ops, p);
249 	if (!p->irq_domain) {
250 		ret = -ENXIO;
251 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
252 		goto err2;
253 	}
254 
255 	/* request interrupts one by one */
256 	for (k = 0; k < p->number_of_irqs; k++) {
257 		if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
258 				0, name, &p->irq[k])) {
259 			dev_err(&pdev->dev, "failed to request IRQ\n");
260 			ret = -ENOENT;
261 			goto err3;
262 		}
263 	}
264 
265 	dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
266 
267 	return 0;
268 err3:
269 	while (--k >= 0)
270 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
271 
272 	irq_domain_remove(p->irq_domain);
273 err2:
274 	iounmap(p->iomem);
275 err1:
276 	pm_runtime_put(&pdev->dev);
277 	pm_runtime_disable(&pdev->dev);
278 	kfree(p);
279 err0:
280 	return ret;
281 }
282 
283 static int irqc_remove(struct platform_device *pdev)
284 {
285 	struct irqc_priv *p = platform_get_drvdata(pdev);
286 	int k;
287 
288 	for (k = 0; k < p->number_of_irqs; k++)
289 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
290 
291 	irq_domain_remove(p->irq_domain);
292 	iounmap(p->iomem);
293 	pm_runtime_put(&pdev->dev);
294 	pm_runtime_disable(&pdev->dev);
295 	kfree(p);
296 	return 0;
297 }
298 
299 static const struct of_device_id irqc_dt_ids[] = {
300 	{ .compatible = "renesas,irqc", },
301 	{},
302 };
303 MODULE_DEVICE_TABLE(of, irqc_dt_ids);
304 
305 static struct platform_driver irqc_device_driver = {
306 	.probe		= irqc_probe,
307 	.remove		= irqc_remove,
308 	.driver		= {
309 		.name	= "renesas_irqc",
310 		.of_match_table	= irqc_dt_ids,
311 	}
312 };
313 
314 static int __init irqc_init(void)
315 {
316 	return platform_driver_register(&irqc_device_driver);
317 }
318 postcore_initcall(irqc_init);
319 
320 static void __exit irqc_exit(void)
321 {
322 	platform_driver_unregister(&irqc_device_driver);
323 }
324 module_exit(irqc_exit);
325 
326 MODULE_AUTHOR("Magnus Damm");
327 MODULE_DESCRIPTION("Renesas IRQC Driver");
328 MODULE_LICENSE("GPL v2");
329