xref: /openbmc/linux/drivers/irqchip/qcom-pdc.c (revision d9fd5a71)
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/of.h>
15 #include <linux/of_address.h>
16 #include <linux/of_device.h>
17 #include <linux/soc/qcom/irq.h>
18 #include <linux/spinlock.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21 
22 #define PDC_MAX_IRQS		168
23 #define PDC_MAX_GPIO_IRQS	256
24 
25 #define CLEAR_INTR(reg, intr)	(reg & ~(1 << intr))
26 #define ENABLE_INTR(reg, intr)	(reg | (1 << intr))
27 
28 #define IRQ_ENABLE_BANK		0x10
29 #define IRQ_i_CFG		0x110
30 
31 #define PDC_NO_PARENT_IRQ	~0UL
32 
33 struct pdc_pin_region {
34 	u32 pin_base;
35 	u32 parent_base;
36 	u32 cnt;
37 };
38 
39 static DEFINE_RAW_SPINLOCK(pdc_lock);
40 static void __iomem *pdc_base;
41 static struct pdc_pin_region *pdc_region;
42 static int pdc_region_cnt;
43 
44 static void pdc_reg_write(int reg, u32 i, u32 val)
45 {
46 	writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
47 }
48 
49 static u32 pdc_reg_read(int reg, u32 i)
50 {
51 	return readl_relaxed(pdc_base + reg + i * sizeof(u32));
52 }
53 
54 static int qcom_pdc_gic_get_irqchip_state(struct irq_data *d,
55 					  enum irqchip_irq_state which,
56 					  bool *state)
57 {
58 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
59 		return 0;
60 
61 	return irq_chip_get_parent_state(d, which, state);
62 }
63 
64 static int qcom_pdc_gic_set_irqchip_state(struct irq_data *d,
65 					  enum irqchip_irq_state which,
66 					  bool value)
67 {
68 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
69 		return 0;
70 
71 	return irq_chip_set_parent_state(d, which, value);
72 }
73 
74 static void pdc_enable_intr(struct irq_data *d, bool on)
75 {
76 	int pin_out = d->hwirq;
77 	u32 index, mask;
78 	u32 enable;
79 
80 	index = pin_out / 32;
81 	mask = pin_out % 32;
82 
83 	raw_spin_lock(&pdc_lock);
84 	enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
85 	enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
86 	pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
87 	raw_spin_unlock(&pdc_lock);
88 }
89 
90 static void qcom_pdc_gic_disable(struct irq_data *d)
91 {
92 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
93 		return;
94 
95 	pdc_enable_intr(d, false);
96 	irq_chip_disable_parent(d);
97 }
98 
99 static void qcom_pdc_gic_enable(struct irq_data *d)
100 {
101 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
102 		return;
103 
104 	pdc_enable_intr(d, true);
105 	irq_chip_enable_parent(d);
106 }
107 
108 static void qcom_pdc_gic_mask(struct irq_data *d)
109 {
110 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
111 		return;
112 
113 	irq_chip_mask_parent(d);
114 }
115 
116 static void qcom_pdc_gic_unmask(struct irq_data *d)
117 {
118 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
119 		return;
120 
121 	irq_chip_unmask_parent(d);
122 }
123 
124 /*
125  * GIC does not handle falling edge or active low. To allow falling edge and
126  * active low interrupts to be handled at GIC, PDC has an inverter that inverts
127  * falling edge into a rising edge and active low into an active high.
128  * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
129  * set as per the table below.
130  * Level sensitive active low    LOW
131  * Rising edge sensitive         NOT USED
132  * Falling edge sensitive        LOW
133  * Dual Edge sensitive           NOT USED
134  * Level sensitive active High   HIGH
135  * Falling Edge sensitive        NOT USED
136  * Rising edge sensitive         HIGH
137  * Dual Edge sensitive           HIGH
138  */
139 enum pdc_irq_config_bits {
140 	PDC_LEVEL_LOW		= 0b000,
141 	PDC_EDGE_FALLING	= 0b010,
142 	PDC_LEVEL_HIGH		= 0b100,
143 	PDC_EDGE_RISING		= 0b110,
144 	PDC_EDGE_DUAL		= 0b111,
145 };
146 
147 /**
148  * qcom_pdc_gic_set_type: Configure PDC for the interrupt
149  *
150  * @d: the interrupt data
151  * @type: the interrupt type
152  *
153  * If @type is edge triggered, forward that as Rising edge as PDC
154  * takes care of converting falling edge to rising edge signal
155  * If @type is level, then forward that as level high as PDC
156  * takes care of converting falling edge to rising edge signal
157  */
158 static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
159 {
160 	int pin_out = d->hwirq;
161 	enum pdc_irq_config_bits pdc_type;
162 	enum pdc_irq_config_bits old_pdc_type;
163 	int ret;
164 
165 	if (pin_out == GPIO_NO_WAKE_IRQ)
166 		return 0;
167 
168 	switch (type) {
169 	case IRQ_TYPE_EDGE_RISING:
170 		pdc_type = PDC_EDGE_RISING;
171 		break;
172 	case IRQ_TYPE_EDGE_FALLING:
173 		pdc_type = PDC_EDGE_FALLING;
174 		type = IRQ_TYPE_EDGE_RISING;
175 		break;
176 	case IRQ_TYPE_EDGE_BOTH:
177 		pdc_type = PDC_EDGE_DUAL;
178 		type = IRQ_TYPE_EDGE_RISING;
179 		break;
180 	case IRQ_TYPE_LEVEL_HIGH:
181 		pdc_type = PDC_LEVEL_HIGH;
182 		break;
183 	case IRQ_TYPE_LEVEL_LOW:
184 		pdc_type = PDC_LEVEL_LOW;
185 		type = IRQ_TYPE_LEVEL_HIGH;
186 		break;
187 	default:
188 		WARN_ON(1);
189 		return -EINVAL;
190 	}
191 
192 	old_pdc_type = pdc_reg_read(IRQ_i_CFG, pin_out);
193 	pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
194 
195 	ret = irq_chip_set_type_parent(d, type);
196 	if (ret)
197 		return ret;
198 
199 	/*
200 	 * When we change types the PDC can give a phantom interrupt.
201 	 * Clear it.  Specifically the phantom shows up when reconfiguring
202 	 * polarity of interrupt without changing the state of the signal
203 	 * but let's be consistent and clear it always.
204 	 *
205 	 * Doing this works because we have IRQCHIP_SET_TYPE_MASKED so the
206 	 * interrupt will be cleared before the rest of the system sees it.
207 	 */
208 	if (old_pdc_type != pdc_type)
209 		irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, false);
210 
211 	return 0;
212 }
213 
214 static struct irq_chip qcom_pdc_gic_chip = {
215 	.name			= "PDC",
216 	.irq_eoi		= irq_chip_eoi_parent,
217 	.irq_mask		= qcom_pdc_gic_mask,
218 	.irq_unmask		= qcom_pdc_gic_unmask,
219 	.irq_disable		= qcom_pdc_gic_disable,
220 	.irq_enable		= qcom_pdc_gic_enable,
221 	.irq_get_irqchip_state	= qcom_pdc_gic_get_irqchip_state,
222 	.irq_set_irqchip_state	= qcom_pdc_gic_set_irqchip_state,
223 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
224 	.irq_set_type		= qcom_pdc_gic_set_type,
225 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
226 				  IRQCHIP_SET_TYPE_MASKED |
227 				  IRQCHIP_SKIP_SET_WAKE |
228 				  IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
229 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
230 	.irq_set_affinity	= irq_chip_set_affinity_parent,
231 };
232 
233 static irq_hw_number_t get_parent_hwirq(int pin)
234 {
235 	int i;
236 	struct pdc_pin_region *region;
237 
238 	for (i = 0; i < pdc_region_cnt; i++) {
239 		region = &pdc_region[i];
240 		if (pin >= region->pin_base &&
241 		    pin < region->pin_base + region->cnt)
242 			return (region->parent_base + pin - region->pin_base);
243 	}
244 
245 	return PDC_NO_PARENT_IRQ;
246 }
247 
248 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
249 			      unsigned long *hwirq, unsigned int *type)
250 {
251 	if (is_of_node(fwspec->fwnode)) {
252 		if (fwspec->param_count != 2)
253 			return -EINVAL;
254 
255 		*hwirq = fwspec->param[0];
256 		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
257 		return 0;
258 	}
259 
260 	return -EINVAL;
261 }
262 
263 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
264 			  unsigned int nr_irqs, void *data)
265 {
266 	struct irq_fwspec *fwspec = data;
267 	struct irq_fwspec parent_fwspec;
268 	irq_hw_number_t hwirq, parent_hwirq;
269 	unsigned int type;
270 	int ret;
271 
272 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
273 	if (ret)
274 		return ret;
275 
276 	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
277 					     &qcom_pdc_gic_chip, NULL);
278 	if (ret)
279 		return ret;
280 
281 	parent_hwirq = get_parent_hwirq(hwirq);
282 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
283 		return 0;
284 
285 	if (type & IRQ_TYPE_EDGE_BOTH)
286 		type = IRQ_TYPE_EDGE_RISING;
287 
288 	if (type & IRQ_TYPE_LEVEL_MASK)
289 		type = IRQ_TYPE_LEVEL_HIGH;
290 
291 	parent_fwspec.fwnode      = domain->parent->fwnode;
292 	parent_fwspec.param_count = 3;
293 	parent_fwspec.param[0]    = 0;
294 	parent_fwspec.param[1]    = parent_hwirq;
295 	parent_fwspec.param[2]    = type;
296 
297 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
298 					    &parent_fwspec);
299 }
300 
301 static const struct irq_domain_ops qcom_pdc_ops = {
302 	.translate	= qcom_pdc_translate,
303 	.alloc		= qcom_pdc_alloc,
304 	.free		= irq_domain_free_irqs_common,
305 };
306 
307 static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
308 			       unsigned int nr_irqs, void *data)
309 {
310 	struct irq_fwspec *fwspec = data;
311 	struct irq_fwspec parent_fwspec;
312 	irq_hw_number_t hwirq, parent_hwirq;
313 	unsigned int type;
314 	int ret;
315 
316 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
317 	if (ret)
318 		return ret;
319 
320 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
321 					    &qcom_pdc_gic_chip, NULL);
322 	if (ret)
323 		return ret;
324 
325 	if (hwirq == GPIO_NO_WAKE_IRQ)
326 		return 0;
327 
328 	parent_hwirq = get_parent_hwirq(hwirq);
329 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
330 		return 0;
331 
332 	if (type & IRQ_TYPE_EDGE_BOTH)
333 		type = IRQ_TYPE_EDGE_RISING;
334 
335 	if (type & IRQ_TYPE_LEVEL_MASK)
336 		type = IRQ_TYPE_LEVEL_HIGH;
337 
338 	parent_fwspec.fwnode      = domain->parent->fwnode;
339 	parent_fwspec.param_count = 3;
340 	parent_fwspec.param[0]    = 0;
341 	parent_fwspec.param[1]    = parent_hwirq;
342 	parent_fwspec.param[2]    = type;
343 
344 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
345 					    &parent_fwspec);
346 }
347 
348 static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
349 				       struct irq_fwspec *fwspec,
350 				       enum irq_domain_bus_token bus_token)
351 {
352 	return bus_token == DOMAIN_BUS_WAKEUP;
353 }
354 
355 static const struct irq_domain_ops qcom_pdc_gpio_ops = {
356 	.select		= qcom_pdc_gpio_domain_select,
357 	.alloc		= qcom_pdc_gpio_alloc,
358 	.free		= irq_domain_free_irqs_common,
359 };
360 
361 static int pdc_setup_pin_mapping(struct device_node *np)
362 {
363 	int ret, n, i;
364 	u32 irq_index, reg_index, val;
365 
366 	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
367 	if (n <= 0 || n % 3)
368 		return -EINVAL;
369 
370 	pdc_region_cnt = n / 3;
371 	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
372 	if (!pdc_region) {
373 		pdc_region_cnt = 0;
374 		return -ENOMEM;
375 	}
376 
377 	for (n = 0; n < pdc_region_cnt; n++) {
378 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
379 						 n * 3 + 0,
380 						 &pdc_region[n].pin_base);
381 		if (ret)
382 			return ret;
383 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
384 						 n * 3 + 1,
385 						 &pdc_region[n].parent_base);
386 		if (ret)
387 			return ret;
388 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
389 						 n * 3 + 2,
390 						 &pdc_region[n].cnt);
391 		if (ret)
392 			return ret;
393 
394 		for (i = 0; i < pdc_region[n].cnt; i++) {
395 			reg_index = (i + pdc_region[n].pin_base) >> 5;
396 			irq_index = (i + pdc_region[n].pin_base) & 0x1f;
397 			val = pdc_reg_read(IRQ_ENABLE_BANK, reg_index);
398 			val &= ~BIT(irq_index);
399 			pdc_reg_write(IRQ_ENABLE_BANK, reg_index, val);
400 		}
401 	}
402 
403 	return 0;
404 }
405 
406 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
407 {
408 	struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
409 	int ret;
410 
411 	pdc_base = of_iomap(node, 0);
412 	if (!pdc_base) {
413 		pr_err("%pOF: unable to map PDC registers\n", node);
414 		return -ENXIO;
415 	}
416 
417 	parent_domain = irq_find_host(parent);
418 	if (!parent_domain) {
419 		pr_err("%pOF: unable to find PDC's parent domain\n", node);
420 		ret = -ENXIO;
421 		goto fail;
422 	}
423 
424 	ret = pdc_setup_pin_mapping(node);
425 	if (ret) {
426 		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
427 		goto fail;
428 	}
429 
430 	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
431 						 of_fwnode_handle(node),
432 						 &qcom_pdc_ops, NULL);
433 	if (!pdc_domain) {
434 		pr_err("%pOF: GIC domain add failed\n", node);
435 		ret = -ENOMEM;
436 		goto fail;
437 	}
438 
439 	pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
440 					IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
441 					PDC_MAX_GPIO_IRQS,
442 					of_fwnode_handle(node),
443 					&qcom_pdc_gpio_ops, NULL);
444 	if (!pdc_gpio_domain) {
445 		pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
446 		ret = -ENOMEM;
447 		goto remove;
448 	}
449 
450 	irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
451 
452 	return 0;
453 
454 remove:
455 	irq_domain_remove(pdc_domain);
456 fail:
457 	kfree(pdc_region);
458 	iounmap(pdc_base);
459 	return ret;
460 }
461 
462 IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
463