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/platform_data/irq-renesas-irqc.h>
33 #include <linux/pm_runtime.h>
34 
35 #define IRQC_IRQ_MAX	32	/* maximum 32 interrupts per driver instance */
36 
37 #define IRQC_REQ_STS	0x00	/* Interrupt Request Status Register */
38 #define IRQC_EN_STS	0x04	/* Interrupt Enable Status Register */
39 #define IRQC_EN_SET	0x08	/* Interrupt Enable Set Register */
40 #define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
41 				/* SYS-CPU vs. RT-CPU */
42 #define DETECT_STATUS	0x100	/* IRQn Detect Status Register */
43 #define MONITOR		0x104	/* IRQn Signal Level Monitor Register */
44 #define HLVL_STS	0x108	/* IRQn High Level Detect Status Register */
45 #define LLVL_STS	0x10c	/* IRQn Low Level Detect Status Register */
46 #define S_R_EDGE_STS	0x110	/* IRQn Sync Rising Edge Detect Status Reg. */
47 #define S_F_EDGE_STS	0x114	/* IRQn Sync Falling Edge Detect Status Reg. */
48 #define A_R_EDGE_STS	0x118	/* IRQn Async Rising Edge Detect Status Reg. */
49 #define A_F_EDGE_STS	0x11c	/* IRQn Async Falling Edge Detect Status Reg. */
50 #define CHTEN_STS	0x120	/* Chattering Reduction Status Register */
51 #define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
52 				/* IRQn Configuration Register */
53 
54 struct irqc_irq {
55 	int hw_irq;
56 	int requested_irq;
57 	int domain_irq;
58 	struct irqc_priv *p;
59 };
60 
61 struct irqc_priv {
62 	void __iomem *iomem;
63 	void __iomem *cpu_int_base;
64 	struct irqc_irq irq[IRQC_IRQ_MAX];
65 	struct renesas_irqc_config config;
66 	unsigned int number_of_irqs;
67 	struct platform_device *pdev;
68 	struct irq_chip irq_chip;
69 	struct irq_domain *irq_domain;
70 	struct clk *clk;
71 };
72 
73 static void irqc_dbg(struct irqc_irq *i, char *str)
74 {
75 	dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
76 		str, i->requested_irq, i->hw_irq, i->domain_irq);
77 }
78 
79 static void irqc_irq_enable(struct irq_data *d)
80 {
81 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
82 	int hw_irq = irqd_to_hwirq(d);
83 
84 	irqc_dbg(&p->irq[hw_irq], "enable");
85 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_SET);
86 }
87 
88 static void irqc_irq_disable(struct irq_data *d)
89 {
90 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
91 	int hw_irq = irqd_to_hwirq(d);
92 
93 	irqc_dbg(&p->irq[hw_irq], "disable");
94 	iowrite32(BIT(hw_irq), p->cpu_int_base + IRQC_EN_STS);
95 }
96 
97 static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
98 	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
99 	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
100 	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
101 	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
102 	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
103 };
104 
105 static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
106 {
107 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
108 	int hw_irq = irqd_to_hwirq(d);
109 	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
110 	u32 tmp;
111 
112 	irqc_dbg(&p->irq[hw_irq], "sense");
113 
114 	if (!value)
115 		return -EINVAL;
116 
117 	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
118 	tmp &= ~0x3f;
119 	tmp |= value;
120 	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
121 	return 0;
122 }
123 
124 static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
125 {
126 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
127 
128 	if (!p->clk)
129 		return 0;
130 
131 	if (on)
132 		clk_enable(p->clk);
133 	else
134 		clk_disable(p->clk);
135 
136 	return 0;
137 }
138 
139 static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
140 {
141 	struct irqc_irq *i = dev_id;
142 	struct irqc_priv *p = i->p;
143 	u32 bit = BIT(i->hw_irq);
144 
145 	irqc_dbg(i, "demux1");
146 
147 	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
148 		iowrite32(bit, p->iomem + DETECT_STATUS);
149 		irqc_dbg(i, "demux2");
150 		generic_handle_irq(i->domain_irq);
151 		return IRQ_HANDLED;
152 	}
153 	return IRQ_NONE;
154 }
155 
156 static int irqc_irq_domain_map(struct irq_domain *h, unsigned int virq,
157 			       irq_hw_number_t hw)
158 {
159 	struct irqc_priv *p = h->host_data;
160 
161 	p->irq[hw].domain_irq = virq;
162 	p->irq[hw].hw_irq = hw;
163 
164 	irqc_dbg(&p->irq[hw], "map");
165 	irq_set_chip_data(virq, h->host_data);
166 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
167 	set_irq_flags(virq, IRQF_VALID); /* kill me now */
168 	return 0;
169 }
170 
171 static struct irq_domain_ops irqc_irq_domain_ops = {
172 	.map	= irqc_irq_domain_map,
173 	.xlate  = irq_domain_xlate_twocell,
174 };
175 
176 static int irqc_probe(struct platform_device *pdev)
177 {
178 	struct renesas_irqc_config *pdata = pdev->dev.platform_data;
179 	struct irqc_priv *p;
180 	struct resource *io;
181 	struct resource *irq;
182 	struct irq_chip *irq_chip;
183 	const char *name = dev_name(&pdev->dev);
184 	int ret;
185 	int k;
186 
187 	p = kzalloc(sizeof(*p), GFP_KERNEL);
188 	if (!p) {
189 		dev_err(&pdev->dev, "failed to allocate driver data\n");
190 		ret = -ENOMEM;
191 		goto err0;
192 	}
193 
194 	/* deal with driver instance configuration */
195 	if (pdata)
196 		memcpy(&p->config, pdata, sizeof(*pdata));
197 
198 	p->pdev = pdev;
199 	platform_set_drvdata(pdev, p);
200 
201 	p->clk = devm_clk_get(&pdev->dev, NULL);
202 	if (IS_ERR(p->clk)) {
203 		dev_warn(&pdev->dev, "unable to get clock\n");
204 		p->clk = NULL;
205 	}
206 
207 	pm_runtime_enable(&pdev->dev);
208 	pm_runtime_get_sync(&pdev->dev);
209 
210 	/* get hold of manadatory IOMEM */
211 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
212 	if (!io) {
213 		dev_err(&pdev->dev, "not enough IOMEM resources\n");
214 		ret = -EINVAL;
215 		goto err1;
216 	}
217 
218 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
219 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
220 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
221 		if (!irq)
222 			break;
223 
224 		p->irq[k].p = p;
225 		p->irq[k].requested_irq = irq->start;
226 	}
227 
228 	p->number_of_irqs = k;
229 	if (p->number_of_irqs < 1) {
230 		dev_err(&pdev->dev, "not enough IRQ resources\n");
231 		ret = -EINVAL;
232 		goto err1;
233 	}
234 
235 	/* ioremap IOMEM and setup read/write callbacks */
236 	p->iomem = ioremap_nocache(io->start, resource_size(io));
237 	if (!p->iomem) {
238 		dev_err(&pdev->dev, "failed to remap IOMEM\n");
239 		ret = -ENXIO;
240 		goto err2;
241 	}
242 
243 	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
244 
245 	irq_chip = &p->irq_chip;
246 	irq_chip->name = name;
247 	irq_chip->irq_mask = irqc_irq_disable;
248 	irq_chip->irq_unmask = irqc_irq_enable;
249 	irq_chip->irq_set_type = irqc_irq_set_type;
250 	irq_chip->irq_set_wake = irqc_irq_set_wake;
251 	irq_chip->flags	= IRQCHIP_MASK_ON_SUSPEND;
252 
253 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
254 					      p->number_of_irqs,
255 					      p->config.irq_base,
256 					      &irqc_irq_domain_ops, p);
257 	if (!p->irq_domain) {
258 		ret = -ENXIO;
259 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
260 		goto err2;
261 	}
262 
263 	/* request interrupts one by one */
264 	for (k = 0; k < p->number_of_irqs; k++) {
265 		if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
266 				0, name, &p->irq[k])) {
267 			dev_err(&pdev->dev, "failed to request IRQ\n");
268 			ret = -ENOENT;
269 			goto err3;
270 		}
271 	}
272 
273 	dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
274 
275 	/* warn in case of mismatch if irq base is specified */
276 	if (p->config.irq_base) {
277 		if (p->config.irq_base != p->irq[0].domain_irq)
278 			dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
279 				 p->config.irq_base, p->irq[0].domain_irq);
280 	}
281 
282 	return 0;
283 err3:
284 	while (--k >= 0)
285 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
286 
287 	irq_domain_remove(p->irq_domain);
288 err2:
289 	iounmap(p->iomem);
290 err1:
291 	pm_runtime_put(&pdev->dev);
292 	pm_runtime_disable(&pdev->dev);
293 	kfree(p);
294 err0:
295 	return ret;
296 }
297 
298 static int irqc_remove(struct platform_device *pdev)
299 {
300 	struct irqc_priv *p = platform_get_drvdata(pdev);
301 	int k;
302 
303 	for (k = 0; k < p->number_of_irqs; k++)
304 		free_irq(p->irq[k].requested_irq, &p->irq[k]);
305 
306 	irq_domain_remove(p->irq_domain);
307 	iounmap(p->iomem);
308 	pm_runtime_put(&pdev->dev);
309 	pm_runtime_disable(&pdev->dev);
310 	kfree(p);
311 	return 0;
312 }
313 
314 static const struct of_device_id irqc_dt_ids[] = {
315 	{ .compatible = "renesas,irqc", },
316 	{},
317 };
318 MODULE_DEVICE_TABLE(of, irqc_dt_ids);
319 
320 static struct platform_driver irqc_device_driver = {
321 	.probe		= irqc_probe,
322 	.remove		= irqc_remove,
323 	.driver		= {
324 		.name	= "renesas_irqc",
325 		.of_match_table	= irqc_dt_ids,
326 	}
327 };
328 
329 static int __init irqc_init(void)
330 {
331 	return platform_driver_register(&irqc_device_driver);
332 }
333 postcore_initcall(irqc_init);
334 
335 static void __exit irqc_exit(void)
336 {
337 	platform_driver_unregister(&irqc_device_driver);
338 }
339 module_exit(irqc_exit);
340 
341 MODULE_AUTHOR("Magnus Damm");
342 MODULE_DESCRIPTION("Renesas IRQC Driver");
343 MODULE_LICENSE("GPL v2");
344