xref: /linux/drivers/irqchip/irq-imgpdc.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IMG PowerDown Controller (PDC)
4  *
5  * Copyright 2010-2013 Imagination Technologies Ltd.
6  *
7  * Exposes the syswake and PDC peripheral wake interrupts to the system.
8  *
9  */
10 
11 #include <linux/bitops.h>
12 #include <linux/interrupt.h>
13 #include <linux/irqdomain.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/spinlock.h>
19 
20 /* PDC interrupt register numbers */
21 
22 #define PDC_IRQ_STATUS			0x310
23 #define PDC_IRQ_ENABLE			0x314
24 #define PDC_IRQ_CLEAR			0x318
25 #define PDC_IRQ_ROUTE			0x31c
26 #define PDC_SYS_WAKE_BASE		0x330
27 #define PDC_SYS_WAKE_STRIDE		0x8
28 #define PDC_SYS_WAKE_CONFIG_BASE	0x334
29 #define PDC_SYS_WAKE_CONFIG_STRIDE	0x8
30 
31 /* PDC interrupt register field masks */
32 
33 #define PDC_IRQ_SYS3			0x08
34 #define PDC_IRQ_SYS2			0x04
35 #define PDC_IRQ_SYS1			0x02
36 #define PDC_IRQ_SYS0			0x01
37 #define PDC_IRQ_ROUTE_WU_EN_SYS3	0x08000000
38 #define PDC_IRQ_ROUTE_WU_EN_SYS2	0x04000000
39 #define PDC_IRQ_ROUTE_WU_EN_SYS1	0x02000000
40 #define PDC_IRQ_ROUTE_WU_EN_SYS0	0x01000000
41 #define PDC_IRQ_ROUTE_WU_EN_WD		0x00040000
42 #define PDC_IRQ_ROUTE_WU_EN_IR		0x00020000
43 #define PDC_IRQ_ROUTE_WU_EN_RTC		0x00010000
44 #define PDC_IRQ_ROUTE_EXT_EN_SYS3	0x00000800
45 #define PDC_IRQ_ROUTE_EXT_EN_SYS2	0x00000400
46 #define PDC_IRQ_ROUTE_EXT_EN_SYS1	0x00000200
47 #define PDC_IRQ_ROUTE_EXT_EN_SYS0	0x00000100
48 #define PDC_IRQ_ROUTE_EXT_EN_WD		0x00000004
49 #define PDC_IRQ_ROUTE_EXT_EN_IR		0x00000002
50 #define PDC_IRQ_ROUTE_EXT_EN_RTC	0x00000001
51 #define PDC_SYS_WAKE_RESET		0x00000010
52 #define PDC_SYS_WAKE_INT_MODE		0x0000000e
53 #define PDC_SYS_WAKE_INT_MODE_SHIFT	1
54 #define PDC_SYS_WAKE_PIN_VAL		0x00000001
55 
56 /* PDC interrupt constants */
57 
58 #define PDC_SYS_WAKE_INT_LOW		0x0
59 #define PDC_SYS_WAKE_INT_HIGH		0x1
60 #define PDC_SYS_WAKE_INT_DOWN		0x2
61 #define PDC_SYS_WAKE_INT_UP		0x3
62 #define PDC_SYS_WAKE_INT_CHANGE		0x6
63 #define PDC_SYS_WAKE_INT_NONE		0x4
64 
65 /**
66  * struct pdc_intc_priv - private pdc interrupt data.
67  * @nr_perips:		Number of peripheral interrupt signals.
68  * @nr_syswakes:	Number of syswake signals.
69  * @perip_irqs:		List of peripheral IRQ numbers handled.
70  * @syswake_irq:	Shared PDC syswake IRQ number.
71  * @domain:		IRQ domain for PDC peripheral and syswake IRQs.
72  * @pdc_base:		Base of PDC registers.
73  * @irq_route:		Cached version of PDC_IRQ_ROUTE register.
74  * @lock:		Lock to protect the PDC syswake registers and the cached
75  *			values of those registers in this struct.
76  */
77 struct pdc_intc_priv {
78 	unsigned int		nr_perips;
79 	unsigned int		nr_syswakes;
80 	unsigned int		*perip_irqs;
81 	unsigned int		syswake_irq;
82 	struct irq_domain	*domain;
83 	void __iomem		*pdc_base;
84 
85 	u32			irq_route;
86 	raw_spinlock_t		lock;
87 };
88 
89 static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
90 		      unsigned int data)
91 {
92 	iowrite32(data, priv->pdc_base + reg_offs);
93 }
94 
95 static unsigned int pdc_read(struct pdc_intc_priv *priv,
96 			     unsigned int reg_offs)
97 {
98 	return ioread32(priv->pdc_base + reg_offs);
99 }
100 
101 /* Generic IRQ callbacks */
102 
103 #define SYS0_HWIRQ	8
104 
105 static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
106 {
107 	return hw >= SYS0_HWIRQ;
108 }
109 
110 static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
111 {
112 	return hw - SYS0_HWIRQ;
113 }
114 
115 static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
116 {
117 	return SYS0_HWIRQ + syswake;
118 }
119 
120 static struct pdc_intc_priv *irqd_to_priv(struct irq_data *data)
121 {
122 	return (struct pdc_intc_priv *)data->domain->host_data;
123 }
124 
125 /*
126  * perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
127  * wake bits, therefore we cannot use the generic irqchip mask callbacks as they
128  * cache the mask.
129  */
130 
131 static void perip_irq_mask(struct irq_data *data)
132 {
133 	struct pdc_intc_priv *priv = irqd_to_priv(data);
134 
135 	raw_spin_lock(&priv->lock);
136 	priv->irq_route &= ~data->mask;
137 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
138 	raw_spin_unlock(&priv->lock);
139 }
140 
141 static void perip_irq_unmask(struct irq_data *data)
142 {
143 	struct pdc_intc_priv *priv = irqd_to_priv(data);
144 
145 	raw_spin_lock(&priv->lock);
146 	priv->irq_route |= data->mask;
147 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
148 	raw_spin_unlock(&priv->lock);
149 }
150 
151 static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
152 {
153 	struct pdc_intc_priv *priv = irqd_to_priv(data);
154 	unsigned int syswake = hwirq_to_syswake(data->hwirq);
155 	unsigned int irq_mode;
156 	unsigned int soc_sys_wake_regoff, soc_sys_wake;
157 
158 	/* translate to syswake IRQ mode */
159 	switch (flow_type) {
160 	case IRQ_TYPE_EDGE_BOTH:
161 		irq_mode = PDC_SYS_WAKE_INT_CHANGE;
162 		break;
163 	case IRQ_TYPE_EDGE_RISING:
164 		irq_mode = PDC_SYS_WAKE_INT_UP;
165 		break;
166 	case IRQ_TYPE_EDGE_FALLING:
167 		irq_mode = PDC_SYS_WAKE_INT_DOWN;
168 		break;
169 	case IRQ_TYPE_LEVEL_HIGH:
170 		irq_mode = PDC_SYS_WAKE_INT_HIGH;
171 		break;
172 	case IRQ_TYPE_LEVEL_LOW:
173 		irq_mode = PDC_SYS_WAKE_INT_LOW;
174 		break;
175 	default:
176 		return -EINVAL;
177 	}
178 
179 	raw_spin_lock(&priv->lock);
180 
181 	/* set the IRQ mode */
182 	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
183 	soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
184 	soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
185 	soc_sys_wake |= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
186 	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
187 
188 	/* and update the handler */
189 	irq_setup_alt_chip(data, flow_type);
190 
191 	raw_spin_unlock(&priv->lock);
192 
193 	return 0;
194 }
195 
196 /* applies to both peripheral and syswake interrupts */
197 static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
198 {
199 	struct pdc_intc_priv *priv = irqd_to_priv(data);
200 	irq_hw_number_t hw = data->hwirq;
201 	unsigned int mask = (1 << 16) << hw;
202 	unsigned int dst_irq;
203 
204 	raw_spin_lock(&priv->lock);
205 	if (on)
206 		priv->irq_route |= mask;
207 	else
208 		priv->irq_route &= ~mask;
209 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
210 	raw_spin_unlock(&priv->lock);
211 
212 	/* control the destination IRQ wakeup too for standby mode */
213 	if (hwirq_is_syswake(hw))
214 		dst_irq = priv->syswake_irq;
215 	else
216 		dst_irq = priv->perip_irqs[hw];
217 	irq_set_irq_wake(dst_irq, on);
218 
219 	return 0;
220 }
221 
222 static void pdc_intc_perip_isr(struct irq_desc *desc)
223 {
224 	unsigned int irq = irq_desc_get_irq(desc);
225 	struct pdc_intc_priv *priv;
226 	unsigned int i;
227 
228 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
229 
230 	/* find the peripheral number */
231 	for (i = 0; i < priv->nr_perips; ++i)
232 		if (irq == priv->perip_irqs[i])
233 			goto found;
234 
235 	/* should never get here */
236 	return;
237 found:
238 
239 	/* pass on the interrupt */
240 	generic_handle_domain_irq(priv->domain, i);
241 }
242 
243 static void pdc_intc_syswake_isr(struct irq_desc *desc)
244 {
245 	struct pdc_intc_priv *priv;
246 	unsigned int syswake;
247 	unsigned int status;
248 
249 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
250 
251 	status = pdc_read(priv, PDC_IRQ_STATUS) &
252 		 pdc_read(priv, PDC_IRQ_ENABLE);
253 	status &= (1 << priv->nr_syswakes) - 1;
254 
255 	for (syswake = 0; status; status >>= 1, ++syswake) {
256 		/* Has this sys_wake triggered? */
257 		if (!(status & 1))
258 			continue;
259 
260 		generic_handle_domain_irq(priv->domain, syswake_to_hwirq(syswake));
261 	}
262 }
263 
264 static void pdc_intc_setup(struct pdc_intc_priv *priv)
265 {
266 	int i;
267 	unsigned int soc_sys_wake_regoff;
268 	unsigned int soc_sys_wake;
269 
270 	/*
271 	 * Mask all syswake interrupts before routing, or we could receive an
272 	 * interrupt before we're ready to handle it.
273 	 */
274 	pdc_write(priv, PDC_IRQ_ENABLE, 0);
275 
276 	/*
277 	 * Enable routing of all syswakes
278 	 * Disable all wake sources
279 	 */
280 	priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
281 				PDC_IRQ_ROUTE_EXT_EN_SYS0);
282 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
283 
284 	/* Initialise syswake IRQ */
285 	for (i = 0; i < priv->nr_syswakes; ++i) {
286 		/* set the IRQ mode to none */
287 		soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
288 		soc_sys_wake = PDC_SYS_WAKE_INT_NONE
289 				<< PDC_SYS_WAKE_INT_MODE_SHIFT;
290 		pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
291 	}
292 }
293 
294 static int pdc_intc_probe(struct platform_device *pdev)
295 {
296 	struct pdc_intc_priv *priv;
297 	struct device_node *node = pdev->dev.of_node;
298 	struct resource *res_regs;
299 	struct irq_chip_generic *gc;
300 	unsigned int i;
301 	int irq, ret;
302 	u32 val;
303 
304 	if (!node)
305 		return -ENOENT;
306 
307 	/* Get registers */
308 	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
309 	if (res_regs == NULL) {
310 		dev_err(&pdev->dev, "cannot find registers resource\n");
311 		return -ENOENT;
312 	}
313 
314 	/* Allocate driver data */
315 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
316 	if (!priv)
317 		return -ENOMEM;
318 	raw_spin_lock_init(&priv->lock);
319 	platform_set_drvdata(pdev, priv);
320 
321 	/* Ioremap the registers */
322 	priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
323 				      resource_size(res_regs));
324 	if (!priv->pdc_base)
325 		return -EIO;
326 
327 	/* Get number of peripherals */
328 	ret = of_property_read_u32(node, "num-perips", &val);
329 	if (ret) {
330 		dev_err(&pdev->dev, "No num-perips node property found\n");
331 		return -EINVAL;
332 	}
333 	if (val > SYS0_HWIRQ) {
334 		dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
335 		return -EINVAL;
336 	}
337 	priv->nr_perips = val;
338 
339 	/* Get number of syswakes */
340 	ret = of_property_read_u32(node, "num-syswakes", &val);
341 	if (ret) {
342 		dev_err(&pdev->dev, "No num-syswakes node property found\n");
343 		return -EINVAL;
344 	}
345 	if (val > SYS0_HWIRQ) {
346 		dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
347 		return -EINVAL;
348 	}
349 	priv->nr_syswakes = val;
350 
351 	/* Get peripheral IRQ numbers */
352 	priv->perip_irqs = devm_kcalloc(&pdev->dev, 4, priv->nr_perips,
353 					GFP_KERNEL);
354 	if (!priv->perip_irqs)
355 		return -ENOMEM;
356 	for (i = 0; i < priv->nr_perips; ++i) {
357 		irq = platform_get_irq(pdev, 1 + i);
358 		if (irq < 0)
359 			return irq;
360 		priv->perip_irqs[i] = irq;
361 	}
362 	/* check if too many were provided */
363 	if (platform_get_irq(pdev, 1 + i) >= 0) {
364 		dev_err(&pdev->dev, "surplus perip IRQs detected\n");
365 		return -EINVAL;
366 	}
367 
368 	/* Get syswake IRQ number */
369 	irq = platform_get_irq(pdev, 0);
370 	if (irq < 0)
371 		return irq;
372 	priv->syswake_irq = irq;
373 
374 	/* Set up an IRQ domain */
375 	priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
376 					     priv);
377 	if (unlikely(!priv->domain)) {
378 		dev_err(&pdev->dev, "cannot add IRQ domain\n");
379 		return -ENOMEM;
380 	}
381 
382 	/*
383 	 * Set up 2 generic irq chips with 2 chip types.
384 	 * The first one for peripheral irqs (only 1 chip type used)
385 	 * The second one for syswake irqs (edge and level chip types)
386 	 */
387 	ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
388 					     handle_level_irq, 0, 0,
389 					     IRQ_GC_INIT_NESTED_LOCK);
390 	if (ret)
391 		goto err_generic;
392 
393 	/* peripheral interrupt chip */
394 
395 	gc = irq_get_domain_generic_chip(priv->domain, 0);
396 	gc->unused	= ~(BIT(priv->nr_perips) - 1);
397 	gc->reg_base	= priv->pdc_base;
398 	/*
399 	 * IRQ_ROUTE contains wake bits, so we can't use the generic versions as
400 	 * they cache the mask
401 	 */
402 	gc->chip_types[0].regs.mask		= PDC_IRQ_ROUTE;
403 	gc->chip_types[0].chip.irq_mask		= perip_irq_mask;
404 	gc->chip_types[0].chip.irq_unmask	= perip_irq_unmask;
405 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
406 
407 	/* syswake interrupt chip */
408 
409 	gc = irq_get_domain_generic_chip(priv->domain, 8);
410 	gc->unused	= ~(BIT(priv->nr_syswakes) - 1);
411 	gc->reg_base	= priv->pdc_base;
412 
413 	/* edge interrupts */
414 	gc->chip_types[0].type			= IRQ_TYPE_EDGE_BOTH;
415 	gc->chip_types[0].handler		= handle_edge_irq;
416 	gc->chip_types[0].regs.ack		= PDC_IRQ_CLEAR;
417 	gc->chip_types[0].regs.mask		= PDC_IRQ_ENABLE;
418 	gc->chip_types[0].chip.irq_ack		= irq_gc_ack_set_bit;
419 	gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
420 	gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
421 	gc->chip_types[0].chip.irq_set_type	= syswake_irq_set_type;
422 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
423 	/* for standby we pass on to the shared syswake IRQ */
424 	gc->chip_types[0].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
425 
426 	/* level interrupts */
427 	gc->chip_types[1].type			= IRQ_TYPE_LEVEL_MASK;
428 	gc->chip_types[1].handler		= handle_level_irq;
429 	gc->chip_types[1].regs.ack		= PDC_IRQ_CLEAR;
430 	gc->chip_types[1].regs.mask		= PDC_IRQ_ENABLE;
431 	gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
432 	gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
433 	gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
434 	gc->chip_types[1].chip.irq_set_type	= syswake_irq_set_type;
435 	gc->chip_types[1].chip.irq_set_wake	= pdc_irq_set_wake;
436 	/* for standby we pass on to the shared syswake IRQ */
437 	gc->chip_types[1].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
438 
439 	/* Set up the hardware to enable interrupt routing */
440 	pdc_intc_setup(priv);
441 
442 	/* Setup chained handlers for the peripheral IRQs */
443 	for (i = 0; i < priv->nr_perips; ++i) {
444 		irq = priv->perip_irqs[i];
445 		irq_set_chained_handler_and_data(irq, pdc_intc_perip_isr,
446 						 priv);
447 	}
448 
449 	/* Setup chained handler for the syswake IRQ */
450 	irq_set_chained_handler_and_data(priv->syswake_irq,
451 					 pdc_intc_syswake_isr, priv);
452 
453 	dev_info(&pdev->dev,
454 		 "PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
455 		 priv->nr_perips,
456 		 priv->nr_syswakes);
457 
458 	return 0;
459 err_generic:
460 	irq_domain_remove(priv->domain);
461 	return ret;
462 }
463 
464 static void pdc_intc_remove(struct platform_device *pdev)
465 {
466 	struct pdc_intc_priv *priv = platform_get_drvdata(pdev);
467 
468 	irq_domain_remove(priv->domain);
469 }
470 
471 static const struct of_device_id pdc_intc_match[] = {
472 	{ .compatible = "img,pdc-intc" },
473 	{}
474 };
475 
476 static struct platform_driver pdc_intc_driver = {
477 	.driver = {
478 		.name		= "pdc-intc",
479 		.of_match_table	= pdc_intc_match,
480 	},
481 	.probe		= pdc_intc_probe,
482 	.remove_new	= pdc_intc_remove,
483 };
484 
485 static int __init pdc_intc_init(void)
486 {
487 	return platform_driver_register(&pdc_intc_driver);
488 }
489 core_initcall(pdc_intc_init);
490