xref: /linux/drivers/irqchip/qcom-pdc.c (revision 81ef8bf88065b07d597c723ca5b0f1f10a808de4)
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/irq.h>
9 #include <linux/irqchip.h>
10 #include <linux/irqdomain.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_device.h>
16 #include <linux/soc/qcom/irq.h>
17 #include <linux/spinlock.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20 
21 #define PDC_MAX_IRQS		168
22 #define PDC_MAX_GPIO_IRQS	256
23 
24 #define CLEAR_INTR(reg, intr)	(reg & ~(1 << intr))
25 #define ENABLE_INTR(reg, intr)	(reg | (1 << intr))
26 
27 #define IRQ_ENABLE_BANK		0x10
28 #define IRQ_i_CFG		0x110
29 
30 #define PDC_NO_PARENT_IRQ	~0UL
31 
32 struct pdc_pin_region {
33 	u32 pin_base;
34 	u32 parent_base;
35 	u32 cnt;
36 };
37 
38 static DEFINE_RAW_SPINLOCK(pdc_lock);
39 static void __iomem *pdc_base;
40 static struct pdc_pin_region *pdc_region;
41 static int pdc_region_cnt;
42 
43 static void pdc_reg_write(int reg, u32 i, u32 val)
44 {
45 	writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
46 }
47 
48 static u32 pdc_reg_read(int reg, u32 i)
49 {
50 	return readl_relaxed(pdc_base + reg + i * sizeof(u32));
51 }
52 
53 static void pdc_enable_intr(struct irq_data *d, bool on)
54 {
55 	int pin_out = d->hwirq;
56 	u32 index, mask;
57 	u32 enable;
58 
59 	index = pin_out / 32;
60 	mask = pin_out % 32;
61 
62 	raw_spin_lock(&pdc_lock);
63 	enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
64 	enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
65 	pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
66 	raw_spin_unlock(&pdc_lock);
67 }
68 
69 static void qcom_pdc_gic_disable(struct irq_data *d)
70 {
71 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
72 		return;
73 
74 	pdc_enable_intr(d, false);
75 	irq_chip_disable_parent(d);
76 }
77 
78 static void qcom_pdc_gic_enable(struct irq_data *d)
79 {
80 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
81 		return;
82 
83 	pdc_enable_intr(d, true);
84 	irq_chip_enable_parent(d);
85 }
86 
87 static void qcom_pdc_gic_mask(struct irq_data *d)
88 {
89 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
90 		return;
91 
92 	irq_chip_mask_parent(d);
93 }
94 
95 static void qcom_pdc_gic_unmask(struct irq_data *d)
96 {
97 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
98 		return;
99 
100 	irq_chip_unmask_parent(d);
101 }
102 
103 /*
104  * GIC does not handle falling edge or active low. To allow falling edge and
105  * active low interrupts to be handled at GIC, PDC has an inverter that inverts
106  * falling edge into a rising edge and active low into an active high.
107  * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
108  * set as per the table below.
109  * Level sensitive active low    LOW
110  * Rising edge sensitive         NOT USED
111  * Falling edge sensitive        LOW
112  * Dual Edge sensitive           NOT USED
113  * Level sensitive active High   HIGH
114  * Falling Edge sensitive        NOT USED
115  * Rising edge sensitive         HIGH
116  * Dual Edge sensitive           HIGH
117  */
118 enum pdc_irq_config_bits {
119 	PDC_LEVEL_LOW		= 0b000,
120 	PDC_EDGE_FALLING	= 0b010,
121 	PDC_LEVEL_HIGH		= 0b100,
122 	PDC_EDGE_RISING		= 0b110,
123 	PDC_EDGE_DUAL		= 0b111,
124 };
125 
126 /**
127  * qcom_pdc_gic_set_type: Configure PDC for the interrupt
128  *
129  * @d: the interrupt data
130  * @type: the interrupt type
131  *
132  * If @type is edge triggered, forward that as Rising edge as PDC
133  * takes care of converting falling edge to rising edge signal
134  * If @type is level, then forward that as level high as PDC
135  * takes care of converting falling edge to rising edge signal
136  */
137 static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
138 {
139 	int pin_out = d->hwirq;
140 	enum pdc_irq_config_bits pdc_type;
141 
142 	if (pin_out == GPIO_NO_WAKE_IRQ)
143 		return 0;
144 
145 	switch (type) {
146 	case IRQ_TYPE_EDGE_RISING:
147 		pdc_type = PDC_EDGE_RISING;
148 		break;
149 	case IRQ_TYPE_EDGE_FALLING:
150 		pdc_type = PDC_EDGE_FALLING;
151 		type = IRQ_TYPE_EDGE_RISING;
152 		break;
153 	case IRQ_TYPE_EDGE_BOTH:
154 		pdc_type = PDC_EDGE_DUAL;
155 		type = IRQ_TYPE_EDGE_RISING;
156 		break;
157 	case IRQ_TYPE_LEVEL_HIGH:
158 		pdc_type = PDC_LEVEL_HIGH;
159 		break;
160 	case IRQ_TYPE_LEVEL_LOW:
161 		pdc_type = PDC_LEVEL_LOW;
162 		type = IRQ_TYPE_LEVEL_HIGH;
163 		break;
164 	default:
165 		WARN_ON(1);
166 		return -EINVAL;
167 	}
168 
169 	pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
170 
171 	return irq_chip_set_type_parent(d, type);
172 }
173 
174 static struct irq_chip qcom_pdc_gic_chip = {
175 	.name			= "PDC",
176 	.irq_eoi		= irq_chip_eoi_parent,
177 	.irq_mask		= qcom_pdc_gic_mask,
178 	.irq_unmask		= qcom_pdc_gic_unmask,
179 	.irq_disable		= qcom_pdc_gic_disable,
180 	.irq_enable		= qcom_pdc_gic_enable,
181 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
182 	.irq_set_type		= qcom_pdc_gic_set_type,
183 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
184 				  IRQCHIP_SET_TYPE_MASKED |
185 				  IRQCHIP_SKIP_SET_WAKE,
186 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
187 	.irq_set_affinity	= irq_chip_set_affinity_parent,
188 };
189 
190 static irq_hw_number_t get_parent_hwirq(int pin)
191 {
192 	int i;
193 	struct pdc_pin_region *region;
194 
195 	for (i = 0; i < pdc_region_cnt; i++) {
196 		region = &pdc_region[i];
197 		if (pin >= region->pin_base &&
198 		    pin < region->pin_base + region->cnt)
199 			return (region->parent_base + pin - region->pin_base);
200 	}
201 
202 	return PDC_NO_PARENT_IRQ;
203 }
204 
205 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
206 			      unsigned long *hwirq, unsigned int *type)
207 {
208 	if (is_of_node(fwspec->fwnode)) {
209 		if (fwspec->param_count != 2)
210 			return -EINVAL;
211 
212 		*hwirq = fwspec->param[0];
213 		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
214 		return 0;
215 	}
216 
217 	return -EINVAL;
218 }
219 
220 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
221 			  unsigned int nr_irqs, void *data)
222 {
223 	struct irq_fwspec *fwspec = data;
224 	struct irq_fwspec parent_fwspec;
225 	irq_hw_number_t hwirq, parent_hwirq;
226 	unsigned int type;
227 	int ret;
228 
229 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
230 	if (ret)
231 		return ret;
232 
233 	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
234 					     &qcom_pdc_gic_chip, NULL);
235 	if (ret)
236 		return ret;
237 
238 	parent_hwirq = get_parent_hwirq(hwirq);
239 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
240 		return 0;
241 
242 	if (type & IRQ_TYPE_EDGE_BOTH)
243 		type = IRQ_TYPE_EDGE_RISING;
244 
245 	if (type & IRQ_TYPE_LEVEL_MASK)
246 		type = IRQ_TYPE_LEVEL_HIGH;
247 
248 	parent_fwspec.fwnode      = domain->parent->fwnode;
249 	parent_fwspec.param_count = 3;
250 	parent_fwspec.param[0]    = 0;
251 	parent_fwspec.param[1]    = parent_hwirq;
252 	parent_fwspec.param[2]    = type;
253 
254 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
255 					    &parent_fwspec);
256 }
257 
258 static const struct irq_domain_ops qcom_pdc_ops = {
259 	.translate	= qcom_pdc_translate,
260 	.alloc		= qcom_pdc_alloc,
261 	.free		= irq_domain_free_irqs_common,
262 };
263 
264 static int qcom_pdc_gpio_alloc(struct irq_domain *domain, unsigned int virq,
265 			       unsigned int nr_irqs, void *data)
266 {
267 	struct irq_fwspec *fwspec = data;
268 	struct irq_fwspec parent_fwspec;
269 	irq_hw_number_t hwirq, parent_hwirq;
270 	unsigned int type;
271 	int ret;
272 
273 	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
274 	if (ret)
275 		return ret;
276 
277 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
278 					    &qcom_pdc_gic_chip, NULL);
279 	if (ret)
280 		return ret;
281 
282 	if (hwirq == GPIO_NO_WAKE_IRQ)
283 		return 0;
284 
285 	parent_hwirq = get_parent_hwirq(hwirq);
286 	if (parent_hwirq == PDC_NO_PARENT_IRQ)
287 		return 0;
288 
289 	if (type & IRQ_TYPE_EDGE_BOTH)
290 		type = IRQ_TYPE_EDGE_RISING;
291 
292 	if (type & IRQ_TYPE_LEVEL_MASK)
293 		type = IRQ_TYPE_LEVEL_HIGH;
294 
295 	parent_fwspec.fwnode      = domain->parent->fwnode;
296 	parent_fwspec.param_count = 3;
297 	parent_fwspec.param[0]    = 0;
298 	parent_fwspec.param[1]    = parent_hwirq;
299 	parent_fwspec.param[2]    = type;
300 
301 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
302 					    &parent_fwspec);
303 }
304 
305 static int qcom_pdc_gpio_domain_select(struct irq_domain *d,
306 				       struct irq_fwspec *fwspec,
307 				       enum irq_domain_bus_token bus_token)
308 {
309 	return bus_token == DOMAIN_BUS_WAKEUP;
310 }
311 
312 static const struct irq_domain_ops qcom_pdc_gpio_ops = {
313 	.select		= qcom_pdc_gpio_domain_select,
314 	.alloc		= qcom_pdc_gpio_alloc,
315 	.free		= irq_domain_free_irqs_common,
316 };
317 
318 static int pdc_setup_pin_mapping(struct device_node *np)
319 {
320 	int ret, n;
321 
322 	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
323 	if (n <= 0 || n % 3)
324 		return -EINVAL;
325 
326 	pdc_region_cnt = n / 3;
327 	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
328 	if (!pdc_region) {
329 		pdc_region_cnt = 0;
330 		return -ENOMEM;
331 	}
332 
333 	for (n = 0; n < pdc_region_cnt; n++) {
334 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
335 						 n * 3 + 0,
336 						 &pdc_region[n].pin_base);
337 		if (ret)
338 			return ret;
339 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
340 						 n * 3 + 1,
341 						 &pdc_region[n].parent_base);
342 		if (ret)
343 			return ret;
344 		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
345 						 n * 3 + 2,
346 						 &pdc_region[n].cnt);
347 		if (ret)
348 			return ret;
349 	}
350 
351 	return 0;
352 }
353 
354 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
355 {
356 	struct irq_domain *parent_domain, *pdc_domain, *pdc_gpio_domain;
357 	int ret;
358 
359 	pdc_base = of_iomap(node, 0);
360 	if (!pdc_base) {
361 		pr_err("%pOF: unable to map PDC registers\n", node);
362 		return -ENXIO;
363 	}
364 
365 	parent_domain = irq_find_host(parent);
366 	if (!parent_domain) {
367 		pr_err("%pOF: unable to find PDC's parent domain\n", node);
368 		ret = -ENXIO;
369 		goto fail;
370 	}
371 
372 	ret = pdc_setup_pin_mapping(node);
373 	if (ret) {
374 		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
375 		goto fail;
376 	}
377 
378 	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
379 						 of_fwnode_handle(node),
380 						 &qcom_pdc_ops, NULL);
381 	if (!pdc_domain) {
382 		pr_err("%pOF: GIC domain add failed\n", node);
383 		ret = -ENOMEM;
384 		goto fail;
385 	}
386 
387 	pdc_gpio_domain = irq_domain_create_hierarchy(parent_domain,
388 					IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP,
389 					PDC_MAX_GPIO_IRQS,
390 					of_fwnode_handle(node),
391 					&qcom_pdc_gpio_ops, NULL);
392 	if (!pdc_gpio_domain) {
393 		pr_err("%pOF: PDC domain add failed for GPIO domain\n", node);
394 		ret = -ENOMEM;
395 		goto remove;
396 	}
397 
398 	irq_domain_update_bus_token(pdc_gpio_domain, DOMAIN_BUS_WAKEUP);
399 
400 	return 0;
401 
402 remove:
403 	irq_domain_remove(pdc_domain);
404 fail:
405 	kfree(pdc_region);
406 	iounmap(pdc_base);
407 	return ret;
408 }
409 
410 IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
411