xref: /openbmc/linux/drivers/irqchip/qcom-pdc.c (revision 4bb1e4e7)
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 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
210 	.irq_set_affinity	= irq_chip_set_affinity_parent,
211 };
212 
213 static irq_hw_number_t get_parent_hwirq(int pin)
214 {
215 	int i;
216 	struct pdc_pin_region *region;
217 
218 	for (i = 0; i < pdc_region_cnt; i++) {
219 		region = &pdc_region[i];
220 		if (pin >= region->pin_base &&
221 		    pin < region->pin_base + region->cnt)
222 			return (region->parent_base + pin - region->pin_base);
223 	}
224 
225 	return PDC_NO_PARENT_IRQ;
226 }
227 
228 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
229 			      unsigned long *hwirq, unsigned int *type)
230 {
231 	if (is_of_node(fwspec->fwnode)) {
232 		if (fwspec->param_count != 2)
233 			return -EINVAL;
234 
235 		*hwirq = fwspec->param[0];
236 		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
237 		return 0;
238 	}
239 
240 	return -EINVAL;
241 }
242 
243 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
244 			  unsigned int nr_irqs, void *data)
245 {
246 	struct irq_fwspec *fwspec = data;
247 	struct irq_fwspec parent_fwspec;
248 	irq_hw_number_t hwirq, parent_hwirq;
249 	unsigned int type;
250 	int ret;
251 
252 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
253 	if (ret)
254 		return ret;
255 
256 	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
257 					     &qcom_pdc_gic_chip, NULL);
258 	if (ret)
259 		return ret;
260 
261 	parent_hwirq = get_parent_hwirq(hwirq);
262 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
263 		return 0;
264 
265 	if (type & IRQ_TYPE_EDGE_BOTH)
266 		type = IRQ_TYPE_EDGE_RISING;
267 
268 	if (type & IRQ_TYPE_LEVEL_MASK)
269 		type = IRQ_TYPE_LEVEL_HIGH;
270 
271 	parent_fwspec.fwnode      = domain->parent->fwnode;
272 	parent_fwspec.param_count = 3;
273 	parent_fwspec.param[0]    = 0;
274 	parent_fwspec.param[1]    = parent_hwirq;
275 	parent_fwspec.param[2]    = type;
276 
277 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
278 					    &parent_fwspec);
279 }
280 
281 static const struct irq_domain_ops qcom_pdc_ops = {
282 	.translate	= qcom_pdc_translate,
283 	.alloc		= qcom_pdc_alloc,
284 	.free		= irq_domain_free_irqs_common,
285 };
286 
287 static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
288 			       unsigned int nr_irqs, void *data)
289 {
290 	struct irq_fwspec *fwspec = data;
291 	struct irq_fwspec parent_fwspec;
292 	irq_hw_number_t hwirq, parent_hwirq;
293 	unsigned int type;
294 	int ret;
295 
296 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
297 	if (ret)
298 		return ret;
299 
300 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
301 					    &qcom_pdc_gic_chip, NULL);
302 	if (ret)
303 		return ret;
304 
305 	if (hwirq == GPIO_NO_WAKE_IRQ)
306 		return 0;
307 
308 	parent_hwirq = get_parent_hwirq(hwirq);
309 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
310 		return 0;
311 
312 	if (type & IRQ_TYPE_EDGE_BOTH)
313 		type = IRQ_TYPE_EDGE_RISING;
314 
315 	if (type & IRQ_TYPE_LEVEL_MASK)
316 		type = IRQ_TYPE_LEVEL_HIGH;
317 
318 	parent_fwspec.fwnode      = domain->parent->fwnode;
319 	parent_fwspec.param_count = 3;
320 	parent_fwspec.param[0]    = 0;
321 	parent_fwspec.param[1]    = parent_hwirq;
322 	parent_fwspec.param[2]    = type;
323 
324 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
325 					    &parent_fwspec);
326 }
327 
328 static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
329 				       struct irq_fwspec *fwspec,
330 				       enum irq_domain_bus_token bus_token)
331 {
332 	return bus_token == DOMAIN_BUS_WAKEUP;
333 }
334 
335 static const struct irq_domain_ops qcom_pdc_gpio_ops = {
336 	.select		= qcom_pdc_gpio_domain_select,
337 	.alloc		= qcom_pdc_gpio_alloc,
338 	.free		= irq_domain_free_irqs_common,
339 };
340 
341 static int pdc_setup_pin_mapping(struct device_node *np)
342 {
343 	int ret, n;
344 
345 	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
346 	if (n <= 0 || n % 3)
347 		return -EINVAL;
348 
349 	pdc_region_cnt = n / 3;
350 	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
351 	if (!pdc_region) {
352 		pdc_region_cnt = 0;
353 		return -ENOMEM;
354 	}
355 
356 	for (n = 0; n < pdc_region_cnt; n++) {
357 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
358 						 n * 3 + 0,
359 						 &pdc_region[n].pin_base);
360 		if (ret)
361 			return ret;
362 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
363 						 n * 3 + 1,
364 						 &pdc_region[n].parent_base);
365 		if (ret)
366 			return ret;
367 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
368 						 n * 3 + 2,
369 						 &pdc_region[n].cnt);
370 		if (ret)
371 			return ret;
372 	}
373 
374 	return 0;
375 }
376 
377 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
378 {
379 	struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
380 	int ret;
381 
382 	pdc_base = of_iomap(node, 0);
383 	if (!pdc_base) {
384 		pr_err("%pOF: unable to map PDC registers\n", node);
385 		return -ENXIO;
386 	}
387 
388 	parent_domain = irq_find_host(parent);
389 	if (!parent_domain) {
390 		pr_err("%pOF: unable to find PDC's parent domain\n", node);
391 		ret = -ENXIO;
392 		goto fail;
393 	}
394 
395 	ret = pdc_setup_pin_mapping(node);
396 	if (ret) {
397 		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
398 		goto fail;
399 	}
400 
401 	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
402 						 of_fwnode_handle(node),
403 						 &qcom_pdc_ops, NULL);
404 	if (!pdc_domain) {
405 		pr_err("%pOF: GIC domain add failed\n", node);
406 		ret = -ENOMEM;
407 		goto fail;
408 	}
409 
410 	pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
411 					IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
412 					PDC_MAX_GPIO_IRQS,
413 					of_fwnode_handle(node),
414 					&qcom_pdc_gpio_ops, NULL);
415 	if (!pdc_gpio_domain) {
416 		pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
417 		ret = -ENOMEM;
418 		goto remove;
419 	}
420 
421 	irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
422 
423 	return 0;
424 
425 remove:
426 	irq_domain_remove(pdc_domain);
427 fail:
428 	kfree(pdc_region);
429 	iounmap(pdc_base);
430 	return ret;
431 }
432 
433 IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
434