xref: /openbmc/linux/drivers/irqchip/irq-imgpdc.c (revision 089a49b6)
1 /*
2  * IMG PowerDown Controller (PDC)
3  *
4  * Copyright 2010-2013 Imagination Technologies Ltd.
5  *
6  * Exposes the syswake and PDC peripheral wake interrupts to the system.
7  *
8  */
9 
10 #include <linux/bitops.h>
11 #include <linux/interrupt.h>
12 #include <linux/irqdomain.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 
19 /* PDC interrupt register numbers */
20 
21 #define PDC_IRQ_STATUS			0x310
22 #define PDC_IRQ_ENABLE			0x314
23 #define PDC_IRQ_CLEAR			0x318
24 #define PDC_IRQ_ROUTE			0x31c
25 #define PDC_SYS_WAKE_BASE		0x330
26 #define PDC_SYS_WAKE_STRIDE		0x8
27 #define PDC_SYS_WAKE_CONFIG_BASE	0x334
28 #define PDC_SYS_WAKE_CONFIG_STRIDE	0x8
29 
30 /* PDC interrupt register field masks */
31 
32 #define PDC_IRQ_SYS3			0x08
33 #define PDC_IRQ_SYS2			0x04
34 #define PDC_IRQ_SYS1			0x02
35 #define PDC_IRQ_SYS0			0x01
36 #define PDC_IRQ_ROUTE_WU_EN_SYS3	0x08000000
37 #define PDC_IRQ_ROUTE_WU_EN_SYS2	0x04000000
38 #define PDC_IRQ_ROUTE_WU_EN_SYS1	0x02000000
39 #define PDC_IRQ_ROUTE_WU_EN_SYS0	0x01000000
40 #define PDC_IRQ_ROUTE_WU_EN_WD		0x00040000
41 #define PDC_IRQ_ROUTE_WU_EN_IR		0x00020000
42 #define PDC_IRQ_ROUTE_WU_EN_RTC		0x00010000
43 #define PDC_IRQ_ROUTE_EXT_EN_SYS3	0x00000800
44 #define PDC_IRQ_ROUTE_EXT_EN_SYS2	0x00000400
45 #define PDC_IRQ_ROUTE_EXT_EN_SYS1	0x00000200
46 #define PDC_IRQ_ROUTE_EXT_EN_SYS0	0x00000100
47 #define PDC_IRQ_ROUTE_EXT_EN_WD		0x00000004
48 #define PDC_IRQ_ROUTE_EXT_EN_IR		0x00000002
49 #define PDC_IRQ_ROUTE_EXT_EN_RTC	0x00000001
50 #define PDC_SYS_WAKE_RESET		0x00000010
51 #define PDC_SYS_WAKE_INT_MODE		0x0000000e
52 #define PDC_SYS_WAKE_INT_MODE_SHIFT	1
53 #define PDC_SYS_WAKE_PIN_VAL		0x00000001
54 
55 /* PDC interrupt constants */
56 
57 #define PDC_SYS_WAKE_INT_LOW		0x0
58 #define PDC_SYS_WAKE_INT_HIGH		0x1
59 #define PDC_SYS_WAKE_INT_DOWN		0x2
60 #define PDC_SYS_WAKE_INT_UP		0x3
61 #define PDC_SYS_WAKE_INT_CHANGE		0x6
62 #define PDC_SYS_WAKE_INT_NONE		0x4
63 
64 /**
65  * struct pdc_intc_priv - private pdc interrupt data.
66  * @nr_perips:		Number of peripheral interrupt signals.
67  * @nr_syswakes:	Number of syswake signals.
68  * @perip_irqs:		List of peripheral IRQ numbers handled.
69  * @syswake_irq:	Shared PDC syswake IRQ number.
70  * @domain:		IRQ domain for PDC peripheral and syswake IRQs.
71  * @pdc_base:		Base of PDC registers.
72  * @irq_route:		Cached version of PDC_IRQ_ROUTE register.
73  * @lock:		Lock to protect the PDC syswake registers and the cached
74  *			values of those registers in this struct.
75  */
76 struct pdc_intc_priv {
77 	unsigned int		nr_perips;
78 	unsigned int		nr_syswakes;
79 	unsigned int		*perip_irqs;
80 	unsigned int		syswake_irq;
81 	struct irq_domain	*domain;
82 	void __iomem		*pdc_base;
83 
84 	u32			irq_route;
85 	raw_spinlock_t		lock;
86 };
87 
88 static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
89 		      unsigned int data)
90 {
91 	iowrite32(data, priv->pdc_base + reg_offs);
92 }
93 
94 static unsigned int pdc_read(struct pdc_intc_priv *priv,
95 			     unsigned int reg_offs)
96 {
97 	return ioread32(priv->pdc_base + reg_offs);
98 }
99 
100 /* Generic IRQ callbacks */
101 
102 #define SYS0_HWIRQ	8
103 
104 static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
105 {
106 	return hw >= SYS0_HWIRQ;
107 }
108 
109 static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
110 {
111 	return hw - SYS0_HWIRQ;
112 }
113 
114 static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
115 {
116 	return SYS0_HWIRQ + syswake;
117 }
118 
119 static struct pdc_intc_priv *irqd_to_priv(struct irq_data *data)
120 {
121 	return (struct pdc_intc_priv *)data->domain->host_data;
122 }
123 
124 /*
125  * perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
126  * wake bits, therefore we cannot use the generic irqchip mask callbacks as they
127  * cache the mask.
128  */
129 
130 static void perip_irq_mask(struct irq_data *data)
131 {
132 	struct pdc_intc_priv *priv = irqd_to_priv(data);
133 
134 	raw_spin_lock(&priv->lock);
135 	priv->irq_route &= ~data->mask;
136 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
137 	raw_spin_unlock(&priv->lock);
138 }
139 
140 static void perip_irq_unmask(struct irq_data *data)
141 {
142 	struct pdc_intc_priv *priv = irqd_to_priv(data);
143 
144 	raw_spin_lock(&priv->lock);
145 	priv->irq_route |= data->mask;
146 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
147 	raw_spin_unlock(&priv->lock);
148 }
149 
150 static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
151 {
152 	struct pdc_intc_priv *priv = irqd_to_priv(data);
153 	unsigned int syswake = hwirq_to_syswake(data->hwirq);
154 	unsigned int irq_mode;
155 	unsigned int soc_sys_wake_regoff, soc_sys_wake;
156 
157 	/* translate to syswake IRQ mode */
158 	switch (flow_type) {
159 	case IRQ_TYPE_EDGE_BOTH:
160 		irq_mode = PDC_SYS_WAKE_INT_CHANGE;
161 		break;
162 	case IRQ_TYPE_EDGE_RISING:
163 		irq_mode = PDC_SYS_WAKE_INT_UP;
164 		break;
165 	case IRQ_TYPE_EDGE_FALLING:
166 		irq_mode = PDC_SYS_WAKE_INT_DOWN;
167 		break;
168 	case IRQ_TYPE_LEVEL_HIGH:
169 		irq_mode = PDC_SYS_WAKE_INT_HIGH;
170 		break;
171 	case IRQ_TYPE_LEVEL_LOW:
172 		irq_mode = PDC_SYS_WAKE_INT_LOW;
173 		break;
174 	default:
175 		return -EINVAL;
176 	}
177 
178 	raw_spin_lock(&priv->lock);
179 
180 	/* set the IRQ mode */
181 	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
182 	soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
183 	soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
184 	soc_sys_wake |= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
185 	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
186 
187 	/* and update the handler */
188 	irq_setup_alt_chip(data, flow_type);
189 
190 	raw_spin_unlock(&priv->lock);
191 
192 	return 0;
193 }
194 
195 /* applies to both peripheral and syswake interrupts */
196 static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
197 {
198 	struct pdc_intc_priv *priv = irqd_to_priv(data);
199 	irq_hw_number_t hw = data->hwirq;
200 	unsigned int mask = (1 << 16) << hw;
201 	unsigned int dst_irq;
202 
203 	raw_spin_lock(&priv->lock);
204 	if (on)
205 		priv->irq_route |= mask;
206 	else
207 		priv->irq_route &= ~mask;
208 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
209 	raw_spin_unlock(&priv->lock);
210 
211 	/* control the destination IRQ wakeup too for standby mode */
212 	if (hwirq_is_syswake(hw))
213 		dst_irq = priv->syswake_irq;
214 	else
215 		dst_irq = priv->perip_irqs[hw];
216 	irq_set_irq_wake(dst_irq, on);
217 
218 	return 0;
219 }
220 
221 static void pdc_intc_perip_isr(unsigned int irq, struct irq_desc *desc)
222 {
223 	struct pdc_intc_priv *priv;
224 	unsigned int i, irq_no;
225 
226 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
227 
228 	/* find the peripheral number */
229 	for (i = 0; i < priv->nr_perips; ++i)
230 		if (irq == priv->perip_irqs[i])
231 			goto found;
232 
233 	/* should never get here */
234 	return;
235 found:
236 
237 	/* pass on the interrupt */
238 	irq_no = irq_linear_revmap(priv->domain, i);
239 	generic_handle_irq(irq_no);
240 }
241 
242 static void pdc_intc_syswake_isr(unsigned int irq, struct irq_desc *desc)
243 {
244 	struct pdc_intc_priv *priv;
245 	unsigned int syswake, irq_no;
246 	unsigned int status;
247 
248 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
249 
250 	status = pdc_read(priv, PDC_IRQ_STATUS) &
251 		 pdc_read(priv, PDC_IRQ_ENABLE);
252 	status &= (1 << priv->nr_syswakes) - 1;
253 
254 	for (syswake = 0; status; status >>= 1, ++syswake) {
255 		/* Has this sys_wake triggered? */
256 		if (!(status & 1))
257 			continue;
258 
259 		irq_no = irq_linear_revmap(priv->domain,
260 					   syswake_to_hwirq(syswake));
261 		generic_handle_irq(irq_no);
262 	}
263 }
264 
265 static void pdc_intc_setup(struct pdc_intc_priv *priv)
266 {
267 	int i;
268 	unsigned int soc_sys_wake_regoff;
269 	unsigned int soc_sys_wake;
270 
271 	/*
272 	 * Mask all syswake interrupts before routing, or we could receive an
273 	 * interrupt before we're ready to handle it.
274 	 */
275 	pdc_write(priv, PDC_IRQ_ENABLE, 0);
276 
277 	/*
278 	 * Enable routing of all syswakes
279 	 * Disable all wake sources
280 	 */
281 	priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
282 				PDC_IRQ_ROUTE_EXT_EN_SYS0);
283 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
284 
285 	/* Initialise syswake IRQ */
286 	for (i = 0; i < priv->nr_syswakes; ++i) {
287 		/* set the IRQ mode to none */
288 		soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
289 		soc_sys_wake = PDC_SYS_WAKE_INT_NONE
290 				<< PDC_SYS_WAKE_INT_MODE_SHIFT;
291 		pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
292 	}
293 }
294 
295 static int pdc_intc_probe(struct platform_device *pdev)
296 {
297 	struct pdc_intc_priv *priv;
298 	struct device_node *node = pdev->dev.of_node;
299 	struct resource *res_regs;
300 	struct irq_chip_generic *gc;
301 	unsigned int i;
302 	int irq, ret;
303 	u32 val;
304 
305 	if (!node)
306 		return -ENOENT;
307 
308 	/* Get registers */
309 	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
310 	if (res_regs == NULL) {
311 		dev_err(&pdev->dev, "cannot find registers resource\n");
312 		return -ENOENT;
313 	}
314 
315 	/* Allocate driver data */
316 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
317 	if (!priv) {
318 		dev_err(&pdev->dev, "cannot allocate device data\n");
319 		return -ENOMEM;
320 	}
321 	raw_spin_lock_init(&priv->lock);
322 	platform_set_drvdata(pdev, priv);
323 
324 	/* Ioremap the registers */
325 	priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
326 				      res_regs->end - res_regs->start);
327 	if (!priv->pdc_base)
328 		return -EIO;
329 
330 	/* Get number of peripherals */
331 	ret = of_property_read_u32(node, "num-perips", &val);
332 	if (ret) {
333 		dev_err(&pdev->dev, "No num-perips node property found\n");
334 		return -EINVAL;
335 	}
336 	if (val > SYS0_HWIRQ) {
337 		dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
338 		return -EINVAL;
339 	}
340 	priv->nr_perips = val;
341 
342 	/* Get number of syswakes */
343 	ret = of_property_read_u32(node, "num-syswakes", &val);
344 	if (ret) {
345 		dev_err(&pdev->dev, "No num-syswakes node property found\n");
346 		return -EINVAL;
347 	}
348 	if (val > SYS0_HWIRQ) {
349 		dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
350 		return -EINVAL;
351 	}
352 	priv->nr_syswakes = val;
353 
354 	/* Get peripheral IRQ numbers */
355 	priv->perip_irqs = devm_kzalloc(&pdev->dev, 4 * priv->nr_perips,
356 					GFP_KERNEL);
357 	if (!priv->perip_irqs) {
358 		dev_err(&pdev->dev, "cannot allocate perip IRQ list\n");
359 		return -ENOMEM;
360 	}
361 	for (i = 0; i < priv->nr_perips; ++i) {
362 		irq = platform_get_irq(pdev, 1 + i);
363 		if (irq < 0) {
364 			dev_err(&pdev->dev, "cannot find perip IRQ #%u\n", i);
365 			return irq;
366 		}
367 		priv->perip_irqs[i] = irq;
368 	}
369 	/* check if too many were provided */
370 	if (platform_get_irq(pdev, 1 + i) >= 0) {
371 		dev_err(&pdev->dev, "surplus perip IRQs detected\n");
372 		return -EINVAL;
373 	}
374 
375 	/* Get syswake IRQ number */
376 	irq = platform_get_irq(pdev, 0);
377 	if (irq < 0) {
378 		dev_err(&pdev->dev, "cannot find syswake IRQ\n");
379 		return irq;
380 	}
381 	priv->syswake_irq = irq;
382 
383 	/* Set up an IRQ domain */
384 	priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
385 					     priv);
386 	if (unlikely(!priv->domain)) {
387 		dev_err(&pdev->dev, "cannot add IRQ domain\n");
388 		return -ENOMEM;
389 	}
390 
391 	/*
392 	 * Set up 2 generic irq chips with 2 chip types.
393 	 * The first one for peripheral irqs (only 1 chip type used)
394 	 * The second one for syswake irqs (edge and level chip types)
395 	 */
396 	ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
397 					     handle_level_irq, 0, 0,
398 					     IRQ_GC_INIT_NESTED_LOCK);
399 	if (ret)
400 		goto err_generic;
401 
402 	/* peripheral interrupt chip */
403 
404 	gc = irq_get_domain_generic_chip(priv->domain, 0);
405 	gc->unused	= ~(BIT(priv->nr_perips) - 1);
406 	gc->reg_base	= priv->pdc_base;
407 	/*
408 	 * IRQ_ROUTE contains wake bits, so we can't use the generic versions as
409 	 * they cache the mask
410 	 */
411 	gc->chip_types[0].regs.mask		= PDC_IRQ_ROUTE;
412 	gc->chip_types[0].chip.irq_mask		= perip_irq_mask;
413 	gc->chip_types[0].chip.irq_unmask	= perip_irq_unmask;
414 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
415 
416 	/* syswake interrupt chip */
417 
418 	gc = irq_get_domain_generic_chip(priv->domain, 8);
419 	gc->unused	= ~(BIT(priv->nr_syswakes) - 1);
420 	gc->reg_base	= priv->pdc_base;
421 
422 	/* edge interrupts */
423 	gc->chip_types[0].type			= IRQ_TYPE_EDGE_BOTH;
424 	gc->chip_types[0].handler		= handle_edge_irq;
425 	gc->chip_types[0].regs.ack		= PDC_IRQ_CLEAR;
426 	gc->chip_types[0].regs.mask		= PDC_IRQ_ENABLE;
427 	gc->chip_types[0].chip.irq_ack		= irq_gc_ack_set_bit;
428 	gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
429 	gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
430 	gc->chip_types[0].chip.irq_set_type	= syswake_irq_set_type;
431 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
432 	/* for standby we pass on to the shared syswake IRQ */
433 	gc->chip_types[0].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
434 
435 	/* level interrupts */
436 	gc->chip_types[1].type			= IRQ_TYPE_LEVEL_MASK;
437 	gc->chip_types[1].handler		= handle_level_irq;
438 	gc->chip_types[1].regs.ack		= PDC_IRQ_CLEAR;
439 	gc->chip_types[1].regs.mask		= PDC_IRQ_ENABLE;
440 	gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
441 	gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
442 	gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
443 	gc->chip_types[1].chip.irq_set_type	= syswake_irq_set_type;
444 	gc->chip_types[1].chip.irq_set_wake	= pdc_irq_set_wake;
445 	/* for standby we pass on to the shared syswake IRQ */
446 	gc->chip_types[1].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
447 
448 	/* Set up the hardware to enable interrupt routing */
449 	pdc_intc_setup(priv);
450 
451 	/* Setup chained handlers for the peripheral IRQs */
452 	for (i = 0; i < priv->nr_perips; ++i) {
453 		irq = priv->perip_irqs[i];
454 		irq_set_handler_data(irq, priv);
455 		irq_set_chained_handler(irq, pdc_intc_perip_isr);
456 	}
457 
458 	/* Setup chained handler for the syswake IRQ */
459 	irq_set_handler_data(priv->syswake_irq, priv);
460 	irq_set_chained_handler(priv->syswake_irq, pdc_intc_syswake_isr);
461 
462 	dev_info(&pdev->dev,
463 		 "PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
464 		 priv->nr_perips,
465 		 priv->nr_syswakes);
466 
467 	return 0;
468 err_generic:
469 	irq_domain_remove(priv->domain);
470 	return ret;
471 }
472 
473 static int pdc_intc_remove(struct platform_device *pdev)
474 {
475 	struct pdc_intc_priv *priv = platform_get_drvdata(pdev);
476 
477 	irq_domain_remove(priv->domain);
478 	return 0;
479 }
480 
481 static const struct of_device_id pdc_intc_match[] = {
482 	{ .compatible = "img,pdc-intc" },
483 	{}
484 };
485 
486 static struct platform_driver pdc_intc_driver = {
487 	.driver = {
488 		.name		= "pdc-intc",
489 		.of_match_table	= pdc_intc_match,
490 	},
491 	.probe = pdc_intc_probe,
492 	.remove = pdc_intc_remove,
493 };
494 
495 static int __init pdc_intc_init(void)
496 {
497 	return platform_driver_register(&pdc_intc_driver);
498 }
499 core_initcall(pdc_intc_init);
500