xref: /linux/drivers/irqchip/qcom-pdc.c (revision 58f7553fa424fd0fd74e8b796d50c66014cebebe)
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 
163 	if (pin_out == GPIO_NO_WAKE_IRQ)
164 		return 0;
165 
166 	switch (type) {
167 	case IRQ_TYPE_EDGE_RISING:
168 		pdc_type = PDC_EDGE_RISING;
169 		break;
170 	case IRQ_TYPE_EDGE_FALLING:
171 		pdc_type = PDC_EDGE_FALLING;
172 		type = IRQ_TYPE_EDGE_RISING;
173 		break;
174 	case IRQ_TYPE_EDGE_BOTH:
175 		pdc_type = PDC_EDGE_DUAL;
176 		type = IRQ_TYPE_EDGE_RISING;
177 		break;
178 	case IRQ_TYPE_LEVEL_HIGH:
179 		pdc_type = PDC_LEVEL_HIGH;
180 		break;
181 	case IRQ_TYPE_LEVEL_LOW:
182 		pdc_type = PDC_LEVEL_LOW;
183 		type = IRQ_TYPE_LEVEL_HIGH;
184 		break;
185 	default:
186 		WARN_ON(1);
187 		return -EINVAL;
188 	}
189 
190 	pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
191 
192 	return irq_chip_set_type_parent(d, type);
193 }
194 
195 static struct irq_chip qcom_pdc_gic_chip = {
196 	.name			= "PDC",
197 	.irq_eoi		= irq_chip_eoi_parent,
198 	.irq_mask		= qcom_pdc_gic_mask,
199 	.irq_unmask		= qcom_pdc_gic_unmask,
200 	.irq_disable		= qcom_pdc_gic_disable,
201 	.irq_enable		= qcom_pdc_gic_enable,
202 	.irq_get_irqchip_state	= qcom_pdc_gic_get_irqchip_state,
203 	.irq_set_irqchip_state	= qcom_pdc_gic_set_irqchip_state,
204 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
205 	.irq_set_type		= qcom_pdc_gic_set_type,
206 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
207 				  IRQCHIP_SET_TYPE_MASKED |
208 				  IRQCHIP_SKIP_SET_WAKE |
209 				  IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
210 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
211 	.irq_set_affinity	= irq_chip_set_affinity_parent,
212 };
213 
214 static irq_hw_number_t get_parent_hwirq(int pin)
215 {
216 	int i;
217 	struct pdc_pin_region *region;
218 
219 	for (i = 0; i < pdc_region_cnt; i++) {
220 		region = &pdc_region[i];
221 		if (pin >= region->pin_base &&
222 		    pin < region->pin_base + region->cnt)
223 			return (region->parent_base + pin - region->pin_base);
224 	}
225 
226 	return PDC_NO_PARENT_IRQ;
227 }
228 
229 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
230 			      unsigned long *hwirq, unsigned int *type)
231 {
232 	if (is_of_node(fwspec->fwnode)) {
233 		if (fwspec->param_count != 2)
234 			return -EINVAL;
235 
236 		*hwirq = fwspec->param[0];
237 		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
238 		return 0;
239 	}
240 
241 	return -EINVAL;
242 }
243 
244 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
245 			  unsigned int nr_irqs, void *data)
246 {
247 	struct irq_fwspec *fwspec = data;
248 	struct irq_fwspec parent_fwspec;
249 	irq_hw_number_t hwirq, parent_hwirq;
250 	unsigned int type;
251 	int ret;
252 
253 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
254 	if (ret)
255 		return ret;
256 
257 	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
258 					     &qcom_pdc_gic_chip, NULL);
259 	if (ret)
260 		return ret;
261 
262 	parent_hwirq = get_parent_hwirq(hwirq);
263 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
264 		return 0;
265 
266 	if (type & IRQ_TYPE_EDGE_BOTH)
267 		type = IRQ_TYPE_EDGE_RISING;
268 
269 	if (type & IRQ_TYPE_LEVEL_MASK)
270 		type = IRQ_TYPE_LEVEL_HIGH;
271 
272 	parent_fwspec.fwnode      = domain->parent->fwnode;
273 	parent_fwspec.param_count = 3;
274 	parent_fwspec.param[0]    = 0;
275 	parent_fwspec.param[1]    = parent_hwirq;
276 	parent_fwspec.param[2]    = type;
277 
278 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
279 					    &parent_fwspec);
280 }
281 
282 static const struct irq_domain_ops qcom_pdc_ops = {
283 	.translate	= qcom_pdc_translate,
284 	.alloc		= qcom_pdc_alloc,
285 	.free		= irq_domain_free_irqs_common,
286 };
287 
288 static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
289 			       unsigned int nr_irqs, void *data)
290 {
291 	struct irq_fwspec *fwspec = data;
292 	struct irq_fwspec parent_fwspec;
293 	irq_hw_number_t hwirq, parent_hwirq;
294 	unsigned int type;
295 	int ret;
296 
297 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
298 	if (ret)
299 		return ret;
300 
301 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
302 					    &qcom_pdc_gic_chip, NULL);
303 	if (ret)
304 		return ret;
305 
306 	if (hwirq == GPIO_NO_WAKE_IRQ)
307 		return 0;
308 
309 	parent_hwirq = get_parent_hwirq(hwirq);
310 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
311 		return 0;
312 
313 	if (type & IRQ_TYPE_EDGE_BOTH)
314 		type = IRQ_TYPE_EDGE_RISING;
315 
316 	if (type & IRQ_TYPE_LEVEL_MASK)
317 		type = IRQ_TYPE_LEVEL_HIGH;
318 
319 	parent_fwspec.fwnode      = domain->parent->fwnode;
320 	parent_fwspec.param_count = 3;
321 	parent_fwspec.param[0]    = 0;
322 	parent_fwspec.param[1]    = parent_hwirq;
323 	parent_fwspec.param[2]    = type;
324 
325 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
326 					    &parent_fwspec);
327 }
328 
329 static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
330 				       struct irq_fwspec *fwspec,
331 				       enum irq_domain_bus_token bus_token)
332 {
333 	return bus_token == DOMAIN_BUS_WAKEUP;
334 }
335 
336 static const struct irq_domain_ops qcom_pdc_gpio_ops = {
337 	.select		= qcom_pdc_gpio_domain_select,
338 	.alloc		= qcom_pdc_gpio_alloc,
339 	.free		= irq_domain_free_irqs_common,
340 };
341 
342 static int pdc_setup_pin_mapping(struct device_node *np)
343 {
344 	int ret, n, i;
345 	u32 irq_index, reg_index, val;
346 
347 	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
348 	if (n <= 0 || n % 3)
349 		return -EINVAL;
350 
351 	pdc_region_cnt = n / 3;
352 	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
353 	if (!pdc_region) {
354 		pdc_region_cnt = 0;
355 		return -ENOMEM;
356 	}
357 
358 	for (n = 0; n < pdc_region_cnt; n++) {
359 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
360 						 n * 3 + 0,
361 						 &pdc_region[n].pin_base);
362 		if (ret)
363 			return ret;
364 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
365 						 n * 3 + 1,
366 						 &pdc_region[n].parent_base);
367 		if (ret)
368 			return ret;
369 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
370 						 n * 3 + 2,
371 						 &pdc_region[n].cnt);
372 		if (ret)
373 			return ret;
374 
375 		for (i = 0; i < pdc_region[n].cnt; i++) {
376 			reg_index = (i + pdc_region[n].pin_base) >> 5;
377 			irq_index = (i + pdc_region[n].pin_base) & 0x1f;
378 			val = pdc_reg_read(IRQ_ENABLE_BANK, reg_index);
379 			val &= ~BIT(irq_index);
380 			pdc_reg_write(IRQ_ENABLE_BANK, reg_index, val);
381 		}
382 	}
383 
384 	return 0;
385 }
386 
387 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
388 {
389 	struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
390 	int ret;
391 
392 	pdc_base = of_iomap(node, 0);
393 	if (!pdc_base) {
394 		pr_err("%pOF: unable to map PDC registers\n", node);
395 		return -ENXIO;
396 	}
397 
398 	parent_domain = irq_find_host(parent);
399 	if (!parent_domain) {
400 		pr_err("%pOF: unable to find PDC's parent domain\n", node);
401 		ret = -ENXIO;
402 		goto fail;
403 	}
404 
405 	ret = pdc_setup_pin_mapping(node);
406 	if (ret) {
407 		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
408 		goto fail;
409 	}
410 
411 	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
412 						 of_fwnode_handle(node),
413 						 &qcom_pdc_ops, NULL);
414 	if (!pdc_domain) {
415 		pr_err("%pOF: GIC domain add failed\n", node);
416 		ret = -ENOMEM;
417 		goto fail;
418 	}
419 
420 	pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
421 					IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
422 					PDC_MAX_GPIO_IRQS,
423 					of_fwnode_handle(node),
424 					&qcom_pdc_gpio_ops, NULL);
425 	if (!pdc_gpio_domain) {
426 		pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
427 		ret = -ENOMEM;
428 		goto remove;
429 	}
430 
431 	irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
432 
433 	return 0;
434 
435 remove:
436 	irq_domain_remove(pdc_domain);
437 fail:
438 	kfree(pdc_region);
439 	iounmap(pdc_base);
440 	return ret;
441 }
442 
443 IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
444