xref: /linux/drivers/irqchip/qcom-pdc.c (revision 4acd8a4be614a6c191273f2247aff7374a92f318)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2017-2019, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/err.h>
7 #include <linux/init.h>
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/irqchip.h>
11 #include <linux/irqdomain.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_device.h>
18 #include <linux/of_irq.h>
19 #include <linux/soc/qcom/irq.h>
20 #include <linux/spinlock.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 
24 #define PDC_MAX_IRQS		168
25 #define PDC_MAX_GPIO_IRQS	256
26 
27 #define CLEAR_INTR(reg, intr)	(reg & ~(1 << intr))
28 #define ENABLE_INTR(reg, intr)	(reg | (1 << intr))
29 
30 #define IRQ_ENABLE_BANK		0x10
31 #define IRQ_i_CFG		0x110
32 
33 #define PDC_NO_PARENT_IRQ	~0UL
34 
35 struct pdc_pin_region {
36 	u32 pin_base;
37 	u32 parent_base;
38 	u32 cnt;
39 };
40 
41 static DEFINE_RAW_SPINLOCK(pdc_lock);
42 static void __iomem *pdc_base;
43 static struct pdc_pin_region *pdc_region;
44 static int pdc_region_cnt;
45 
46 static void pdc_reg_write(int reg, u32 i, u32 val)
47 {
48 	writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
49 }
50 
51 static u32 pdc_reg_read(int reg, u32 i)
52 {
53 	return readl_relaxed(pdc_base + reg + i * sizeof(u32));
54 }
55 
56 static int qcom_pdc_gic_get_irqchip_state(struct irq_data *d,
57 					  enum irqchip_irq_state which,
58 					  bool *state)
59 {
60 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
61 		return 0;
62 
63 	return irq_chip_get_parent_state(d, which, state);
64 }
65 
66 static int qcom_pdc_gic_set_irqchip_state(struct irq_data *d,
67 					  enum irqchip_irq_state which,
68 					  bool value)
69 {
70 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
71 		return 0;
72 
73 	return irq_chip_set_parent_state(d, which, value);
74 }
75 
76 static void pdc_enable_intr(struct irq_data *d, bool on)
77 {
78 	int pin_out = d->hwirq;
79 	u32 index, mask;
80 	u32 enable;
81 
82 	index = pin_out / 32;
83 	mask = pin_out % 32;
84 
85 	raw_spin_lock(&pdc_lock);
86 	enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
87 	enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
88 	pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
89 	raw_spin_unlock(&pdc_lock);
90 }
91 
92 static void qcom_pdc_gic_disable(struct irq_data *d)
93 {
94 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
95 		return;
96 
97 	pdc_enable_intr(d, false);
98 	irq_chip_disable_parent(d);
99 }
100 
101 static void qcom_pdc_gic_enable(struct irq_data *d)
102 {
103 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
104 		return;
105 
106 	pdc_enable_intr(d, true);
107 	irq_chip_enable_parent(d);
108 }
109 
110 static void qcom_pdc_gic_mask(struct irq_data *d)
111 {
112 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
113 		return;
114 
115 	irq_chip_mask_parent(d);
116 }
117 
118 static void qcom_pdc_gic_unmask(struct irq_data *d)
119 {
120 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
121 		return;
122 
123 	irq_chip_unmask_parent(d);
124 }
125 
126 /*
127  * GIC does not handle falling edge or active low. To allow falling edge and
128  * active low interrupts to be handled at GIC, PDC has an inverter that inverts
129  * falling edge into a rising edge and active low into an active high.
130  * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
131  * set as per the table below.
132  * Level sensitive active low    LOW
133  * Rising edge sensitive         NOT USED
134  * Falling edge sensitive        LOW
135  * Dual Edge sensitive           NOT USED
136  * Level sensitive active High   HIGH
137  * Falling Edge sensitive        NOT USED
138  * Rising edge sensitive         HIGH
139  * Dual Edge sensitive           HIGH
140  */
141 enum pdc_irq_config_bits {
142 	PDC_LEVEL_LOW		= 0b000,
143 	PDC_EDGE_FALLING	= 0b010,
144 	PDC_LEVEL_HIGH		= 0b100,
145 	PDC_EDGE_RISING		= 0b110,
146 	PDC_EDGE_DUAL		= 0b111,
147 };
148 
149 /**
150  * qcom_pdc_gic_set_type: Configure PDC for the interrupt
151  *
152  * @d: the interrupt data
153  * @type: the interrupt type
154  *
155  * If @type is edge triggered, forward that as Rising edge as PDC
156  * takes care of converting falling edge to rising edge signal
157  * If @type is level, then forward that as level high as PDC
158  * takes care of converting falling edge to rising edge signal
159  */
160 static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
161 {
162 	int pin_out = d->hwirq;
163 	enum pdc_irq_config_bits pdc_type;
164 	enum pdc_irq_config_bits old_pdc_type;
165 	int ret;
166 
167 	if (pin_out == GPIO_NO_WAKE_IRQ)
168 		return 0;
169 
170 	switch (type) {
171 	case IRQ_TYPE_EDGE_RISING:
172 		pdc_type = PDC_EDGE_RISING;
173 		break;
174 	case IRQ_TYPE_EDGE_FALLING:
175 		pdc_type = PDC_EDGE_FALLING;
176 		type = IRQ_TYPE_EDGE_RISING;
177 		break;
178 	case IRQ_TYPE_EDGE_BOTH:
179 		pdc_type = PDC_EDGE_DUAL;
180 		type = IRQ_TYPE_EDGE_RISING;
181 		break;
182 	case IRQ_TYPE_LEVEL_HIGH:
183 		pdc_type = PDC_LEVEL_HIGH;
184 		break;
185 	case IRQ_TYPE_LEVEL_LOW:
186 		pdc_type = PDC_LEVEL_LOW;
187 		type = IRQ_TYPE_LEVEL_HIGH;
188 		break;
189 	default:
190 		WARN_ON(1);
191 		return -EINVAL;
192 	}
193 
194 	old_pdc_type = pdc_reg_read(IRQ_i_CFG, pin_out);
195 	pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
196 
197 	ret = irq_chip_set_type_parent(d, type);
198 	if (ret)
199 		return ret;
200 
201 	/*
202 	 * When we change types the PDC can give a phantom interrupt.
203 	 * Clear it.  Specifically the phantom shows up when reconfiguring
204 	 * polarity of interrupt without changing the state of the signal
205 	 * but let's be consistent and clear it always.
206 	 *
207 	 * Doing this works because we have IRQCHIP_SET_TYPE_MASKED so the
208 	 * interrupt will be cleared before the rest of the system sees it.
209 	 */
210 	if (old_pdc_type != pdc_type)
211 		irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, false);
212 
213 	return 0;
214 }
215 
216 static struct irq_chip qcom_pdc_gic_chip = {
217 	.name			= "PDC",
218 	.irq_eoi		= irq_chip_eoi_parent,
219 	.irq_mask		= qcom_pdc_gic_mask,
220 	.irq_unmask		= qcom_pdc_gic_unmask,
221 	.irq_disable		= qcom_pdc_gic_disable,
222 	.irq_enable		= qcom_pdc_gic_enable,
223 	.irq_get_irqchip_state	= qcom_pdc_gic_get_irqchip_state,
224 	.irq_set_irqchip_state	= qcom_pdc_gic_set_irqchip_state,
225 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
226 	.irq_set_type		= qcom_pdc_gic_set_type,
227 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
228 				  IRQCHIP_SET_TYPE_MASKED |
229 				  IRQCHIP_SKIP_SET_WAKE |
230 				  IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
231 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
232 	.irq_set_affinity	= irq_chip_set_affinity_parent,
233 };
234 
235 static irq_hw_number_t get_parent_hwirq(int pin)
236 {
237 	int i;
238 	struct pdc_pin_region *region;
239 
240 	for (i = 0; i < pdc_region_cnt; i++) {
241 		region = &pdc_region[i];
242 		if (pin >= region->pin_base &&
243 		    pin < region->pin_base + region->cnt)
244 			return (region->parent_base + pin - region->pin_base);
245 	}
246 
247 	return PDC_NO_PARENT_IRQ;
248 }
249 
250 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
251 			      unsigned long *hwirq, unsigned int *type)
252 {
253 	if (is_of_node(fwspec->fwnode)) {
254 		if (fwspec->param_count != 2)
255 			return -EINVAL;
256 
257 		*hwirq = fwspec->param[0];
258 		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
259 		return 0;
260 	}
261 
262 	return -EINVAL;
263 }
264 
265 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
266 			  unsigned int nr_irqs, void *data)
267 {
268 	struct irq_fwspec *fwspec = data;
269 	struct irq_fwspec parent_fwspec;
270 	irq_hw_number_t hwirq, parent_hwirq;
271 	unsigned int type;
272 	int ret;
273 
274 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
275 	if (ret)
276 		return ret;
277 
278 	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
279 					     &qcom_pdc_gic_chip, NULL);
280 	if (ret)
281 		return ret;
282 
283 	parent_hwirq = get_parent_hwirq(hwirq);
284 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
285 		return 0;
286 
287 	if (type & IRQ_TYPE_EDGE_BOTH)
288 		type = IRQ_TYPE_EDGE_RISING;
289 
290 	if (type & IRQ_TYPE_LEVEL_MASK)
291 		type = IRQ_TYPE_LEVEL_HIGH;
292 
293 	parent_fwspec.fwnode      = domain->parent->fwnode;
294 	parent_fwspec.param_count = 3;
295 	parent_fwspec.param[0]    = 0;
296 	parent_fwspec.param[1]    = parent_hwirq;
297 	parent_fwspec.param[2]    = type;
298 
299 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
300 					    &parent_fwspec);
301 }
302 
303 static const struct irq_domain_ops qcom_pdc_ops = {
304 	.translate	= qcom_pdc_translate,
305 	.alloc		= qcom_pdc_alloc,
306 	.free		= irq_domain_free_irqs_common,
307 };
308 
309 static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
310 			       unsigned int nr_irqs, void *data)
311 {
312 	struct irq_fwspec *fwspec = data;
313 	struct irq_fwspec parent_fwspec;
314 	irq_hw_number_t hwirq, parent_hwirq;
315 	unsigned int type;
316 	int ret;
317 
318 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
319 	if (ret)
320 		return ret;
321 
322 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
323 					    &qcom_pdc_gic_chip, NULL);
324 	if (ret)
325 		return ret;
326 
327 	if (hwirq == GPIO_NO_WAKE_IRQ)
328 		return 0;
329 
330 	parent_hwirq = get_parent_hwirq(hwirq);
331 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
332 		return 0;
333 
334 	if (type & IRQ_TYPE_EDGE_BOTH)
335 		type = IRQ_TYPE_EDGE_RISING;
336 
337 	if (type & IRQ_TYPE_LEVEL_MASK)
338 		type = IRQ_TYPE_LEVEL_HIGH;
339 
340 	parent_fwspec.fwnode      = domain->parent->fwnode;
341 	parent_fwspec.param_count = 3;
342 	parent_fwspec.param[0]    = 0;
343 	parent_fwspec.param[1]    = parent_hwirq;
344 	parent_fwspec.param[2]    = type;
345 
346 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
347 					    &parent_fwspec);
348 }
349 
350 static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
351 				       struct irq_fwspec *fwspec,
352 				       enum irq_domain_bus_token bus_token)
353 {
354 	return bus_token == DOMAIN_BUS_WAKEUP;
355 }
356 
357 static const struct irq_domain_ops qcom_pdc_gpio_ops = {
358 	.select		= qcom_pdc_gpio_domain_select,
359 	.alloc		= qcom_pdc_gpio_alloc,
360 	.free		= irq_domain_free_irqs_common,
361 };
362 
363 static int pdc_setup_pin_mapping(struct device_node *np)
364 {
365 	int ret, n, i;
366 	u32 irq_index, reg_index, val;
367 
368 	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
369 	if (n <= 0 || n % 3)
370 		return -EINVAL;
371 
372 	pdc_region_cnt = n / 3;
373 	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
374 	if (!pdc_region) {
375 		pdc_region_cnt = 0;
376 		return -ENOMEM;
377 	}
378 
379 	for (n = 0; n < pdc_region_cnt; n++) {
380 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
381 						 n * 3 + 0,
382 						 &pdc_region[n].pin_base);
383 		if (ret)
384 			return ret;
385 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
386 						 n * 3 + 1,
387 						 &pdc_region[n].parent_base);
388 		if (ret)
389 			return ret;
390 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
391 						 n * 3 + 2,
392 						 &pdc_region[n].cnt);
393 		if (ret)
394 			return ret;
395 
396 		for (i = 0; i < pdc_region[n].cnt; i++) {
397 			reg_index = (i + pdc_region[n].pin_base) >> 5;
398 			irq_index = (i + pdc_region[n].pin_base) & 0x1f;
399 			val = pdc_reg_read(IRQ_ENABLE_BANK, reg_index);
400 			val &= ~BIT(irq_index);
401 			pdc_reg_write(IRQ_ENABLE_BANK, reg_index, val);
402 		}
403 	}
404 
405 	return 0;
406 }
407 
408 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
409 {
410 	struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
411 	int ret;
412 
413 	pdc_base = of_iomap(node, 0);
414 	if (!pdc_base) {
415 		pr_err("%pOF: unable to map PDC registers\n", node);
416 		return -ENXIO;
417 	}
418 
419 	parent_domain = irq_find_host(parent);
420 	if (!parent_domain) {
421 		pr_err("%pOF: unable to find PDC's parent domain\n", node);
422 		ret = -ENXIO;
423 		goto fail;
424 	}
425 
426 	ret = pdc_setup_pin_mapping(node);
427 	if (ret) {
428 		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
429 		goto fail;
430 	}
431 
432 	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
433 						 of_fwnode_handle(node),
434 						 &qcom_pdc_ops, NULL);
435 	if (!pdc_domain) {
436 		pr_err("%pOF: GIC domain add failed\n", node);
437 		ret = -ENOMEM;
438 		goto fail;
439 	}
440 
441 	pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
442 					IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
443 					PDC_MAX_GPIO_IRQS,
444 					of_fwnode_handle(node),
445 					&qcom_pdc_gpio_ops, NULL);
446 	if (!pdc_gpio_domain) {
447 		pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
448 		ret = -ENOMEM;
449 		goto remove;
450 	}
451 
452 	irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
453 
454 	return 0;
455 
456 remove:
457 	irq_domain_remove(pdc_domain);
458 fail:
459 	kfree(pdc_region);
460 	iounmap(pdc_base);
461 	return ret;
462 }
463 
464 IRQCHIP_PLATFORM_DRIVER_BEGIN(qcom_pdc)
465 IRQCHIP_MATCH("qcom,pdc", qcom_pdc_init)
466 IRQCHIP_PLATFORM_DRIVER_END(qcom_pdc)
467 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Power Domain Controller");
468 MODULE_LICENSE("GPL v2");
469