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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cristian Birsan <cristian.birsan@microchip.com>
4 * Joshua Henderson <joshua.henderson@microchip.com>
5 * Copyright (C) 2016 Microchip Technology Inc. All rights reserved.
6 */
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/interrupt.h>
10#include <linux/irqdomain.h>
11#include <linux/of_address.h>
12#include <linux/slab.h>
13#include <linux/io.h>
14#include <linux/irqchip.h>
15#include <linux/irq.h>
16
17#include <asm/irq.h>
18#include <asm/traps.h>
19#include <asm/mach-pic32/pic32.h>
20
21#define REG_INTCON 0x0000
22#define REG_INTSTAT 0x0020
23#define REG_IFS_OFFSET 0x0040
24#define REG_IEC_OFFSET 0x00C0
25#define REG_IPC_OFFSET 0x0140
26#define REG_OFF_OFFSET 0x0540
27
28#define MAJPRI_MASK 0x07
29#define SUBPRI_MASK 0x03
30#define PRIORITY_MASK 0x1F
31
32#define PIC32_INT_PRI(pri, subpri) \
33 ((((pri) & MAJPRI_MASK) << 2) | ((subpri) & SUBPRI_MASK))
34
35struct evic_chip_data {
36 u32 irq_types[NR_IRQS];
37 u32 ext_irqs[8];
38};
39
40static struct irq_domain *evic_irq_domain;
41static void __iomem *evic_base;
42
43asmlinkage void __weak plat_irq_dispatch(void)
44{
45 unsigned int irq, hwirq;
46
47 hwirq = readl(evic_base + REG_INTSTAT) & 0xFF;
48 irq = irq_linear_revmap(evic_irq_domain, hwirq);
49 do_IRQ(irq);
50}
51
52static struct evic_chip_data *irqd_to_priv(struct irq_data *data)
53{
54 return (struct evic_chip_data *)data->domain->host_data;
55}
56
57static int pic32_set_ext_polarity(int bit, u32 type)
58{
59 /*
60 * External interrupts can be either edge rising or edge falling,
61 * but not both.
62 */
63 switch (type) {
64 case IRQ_TYPE_EDGE_RISING:
65 writel(BIT(bit), evic_base + PIC32_SET(REG_INTCON));
66 break;
67 case IRQ_TYPE_EDGE_FALLING:
68 writel(BIT(bit), evic_base + PIC32_CLR(REG_INTCON));
69 break;
70 default:
71 return -EINVAL;
72 }
73
74 return 0;
75}
76
77static int pic32_set_type_edge(struct irq_data *data,
78 unsigned int flow_type)
79{
80 struct evic_chip_data *priv = irqd_to_priv(data);
81 int ret;
82 int i;
83
84 if (!(flow_type & IRQ_TYPE_EDGE_BOTH))
85 return -EBADR;
86
87 /* set polarity for external interrupts only */
88 for (i = 0; i < ARRAY_SIZE(priv->ext_irqs); i++) {
89 if (priv->ext_irqs[i] == data->hwirq) {
90 ret = pic32_set_ext_polarity(i, flow_type);
91 if (ret)
92 return ret;
93 }
94 }
95
96 irqd_set_trigger_type(data, flow_type);
97
98 return IRQ_SET_MASK_OK;
99}
100
101static void pic32_bind_evic_interrupt(int irq, int set)
102{
103 writel(set, evic_base + REG_OFF_OFFSET + irq * 4);
104}
105
106static void pic32_set_irq_priority(int irq, int priority)
107{
108 u32 reg, shift;
109
110 reg = irq / 4;
111 shift = (irq % 4) * 8;
112
113 writel(PRIORITY_MASK << shift,
114 evic_base + PIC32_CLR(REG_IPC_OFFSET + reg * 0x10));
115 writel(priority << shift,
116 evic_base + PIC32_SET(REG_IPC_OFFSET + reg * 0x10));
117}
118
119#define IRQ_REG_MASK(_hwirq, _reg, _mask) \
120 do { \
121 _reg = _hwirq / 32; \
122 _mask = 1 << (_hwirq % 32); \
123 } while (0)
124
125static int pic32_irq_domain_map(struct irq_domain *d, unsigned int virq,
126 irq_hw_number_t hw)
127{
128 struct evic_chip_data *priv = d->host_data;
129 struct irq_data *data;
130 int ret;
131 u32 iecclr, ifsclr;
132 u32 reg, mask;
133
134 ret = irq_map_generic_chip(d, virq, hw);
135 if (ret)
136 return ret;
137
138 /*
139 * Piggyback on xlate function to move to an alternate chip as necessary
140 * at time of mapping instead of allowing the flow handler/chip to be
141 * changed later. This requires all interrupts to be configured through
142 * DT.
143 */
144 if (priv->irq_types[hw] & IRQ_TYPE_SENSE_MASK) {
145 data = irq_domain_get_irq_data(d, virq);
146 irqd_set_trigger_type(data, priv->irq_types[hw]);
147 irq_setup_alt_chip(data, priv->irq_types[hw]);
148 }
149
150 IRQ_REG_MASK(hw, reg, mask);
151
152 iecclr = PIC32_CLR(REG_IEC_OFFSET + reg * 0x10);
153 ifsclr = PIC32_CLR(REG_IFS_OFFSET + reg * 0x10);
154
155 /* mask and clear flag */
156 writel(mask, evic_base + iecclr);
157 writel(mask, evic_base + ifsclr);
158
159 /* default priority is required */
160 pic32_set_irq_priority(hw, PIC32_INT_PRI(2, 0));
161
162 return ret;
163}
164
165int pic32_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
166 const u32 *intspec, unsigned int intsize,
167 irq_hw_number_t *out_hwirq, unsigned int *out_type)
168{
169 struct evic_chip_data *priv = d->host_data;
170
171 if (WARN_ON(intsize < 2))
172 return -EINVAL;
173
174 if (WARN_ON(intspec[0] >= NR_IRQS))
175 return -EINVAL;
176
177 *out_hwirq = intspec[0];
178 *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
179
180 priv->irq_types[intspec[0]] = intspec[1] & IRQ_TYPE_SENSE_MASK;
181
182 return 0;
183}
184
185static const struct irq_domain_ops pic32_irq_domain_ops = {
186 .map = pic32_irq_domain_map,
187 .xlate = pic32_irq_domain_xlate,
188};
189
190static void __init pic32_ext_irq_of_init(struct irq_domain *domain)
191{
192 struct device_node *node = irq_domain_get_of_node(domain);
193 struct evic_chip_data *priv = domain->host_data;
194 struct property *prop;
195 const __le32 *p;
196 u32 hwirq;
197 int i = 0;
198 const char *pname = "microchip,external-irqs";
199
200 of_property_for_each_u32(node, pname, prop, p, hwirq) {
201 if (i >= ARRAY_SIZE(priv->ext_irqs)) {
202 pr_warn("More than %d external irq, skip rest\n",
203 ARRAY_SIZE(priv->ext_irqs));
204 break;
205 }
206
207 priv->ext_irqs[i] = hwirq;
208 i++;
209 }
210}
211
212static int __init pic32_of_init(struct device_node *node,
213 struct device_node *parent)
214{
215 struct irq_chip_generic *gc;
216 struct evic_chip_data *priv;
217 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
218 int nchips, ret;
219 int i;
220
221 nchips = DIV_ROUND_UP(NR_IRQS, 32);
222
223 evic_base = of_iomap(node, 0);
224 if (!evic_base)
225 return -ENOMEM;
226
227 priv = kcalloc(nchips, sizeof(*priv), GFP_KERNEL);
228 if (!priv) {
229 ret = -ENOMEM;
230 goto err_iounmap;
231 }
232
233 evic_irq_domain = irq_domain_add_linear(node, nchips * 32,
234 &pic32_irq_domain_ops,
235 priv);
236 if (!evic_irq_domain) {
237 ret = -ENOMEM;
238 goto err_free_priv;
239 }
240
241 /*
242 * The PIC32 EVIC has a linear list of irqs and the type of each
243 * irq is determined by the hardware peripheral the EVIC is arbitrating.
244 * These irq types are defined in the datasheet as "persistent" and
245 * "non-persistent" which are mapped here to level and edge
246 * respectively. To manage the different flow handler requirements of
247 * each irq type, different chip_types are used.
248 */
249 ret = irq_alloc_domain_generic_chips(evic_irq_domain, 32, 2,
250 "evic-level", handle_level_irq,
251 clr, 0, 0);
252 if (ret)
253 goto err_domain_remove;
254
255 board_bind_eic_interrupt = &pic32_bind_evic_interrupt;
256
257 for (i = 0; i < nchips; i++) {
258 u32 ifsclr = PIC32_CLR(REG_IFS_OFFSET + (i * 0x10));
259 u32 iec = REG_IEC_OFFSET + (i * 0x10);
260
261 gc = irq_get_domain_generic_chip(evic_irq_domain, i * 32);
262
263 gc->reg_base = evic_base;
264 gc->unused = 0;
265
266 /*
267 * Level/persistent interrupts have a special requirement that
268 * the condition generating the interrupt be cleared before the
269 * interrupt flag (ifs) can be cleared. chip.irq_eoi is used to
270 * complete the interrupt with an ack.
271 */
272 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
273 gc->chip_types[0].handler = handle_fasteoi_irq;
274 gc->chip_types[0].regs.ack = ifsclr;
275 gc->chip_types[0].regs.mask = iec;
276 gc->chip_types[0].chip.name = "evic-level";
277 gc->chip_types[0].chip.irq_eoi = irq_gc_ack_set_bit;
278 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
279 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
280 gc->chip_types[0].chip.flags = IRQCHIP_SKIP_SET_WAKE;
281
282 /* Edge interrupts */
283 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
284 gc->chip_types[1].handler = handle_edge_irq;
285 gc->chip_types[1].regs.ack = ifsclr;
286 gc->chip_types[1].regs.mask = iec;
287 gc->chip_types[1].chip.name = "evic-edge";
288 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
289 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
290 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
291 gc->chip_types[1].chip.irq_set_type = pic32_set_type_edge;
292 gc->chip_types[1].chip.flags = IRQCHIP_SKIP_SET_WAKE;
293
294 gc->private = &priv[i];
295 }
296
297 irq_set_default_host(evic_irq_domain);
298
299 /*
300 * External interrupts have software configurable edge polarity. These
301 * interrupts are defined in DT allowing polarity to be configured only
302 * for these interrupts when requested.
303 */
304 pic32_ext_irq_of_init(evic_irq_domain);
305
306 return 0;
307
308err_domain_remove:
309 irq_domain_remove(evic_irq_domain);
310
311err_free_priv:
312 kfree(priv);
313
314err_iounmap:
315 iounmap(evic_base);
316
317 return ret;
318}
319
320IRQCHIP_DECLARE(pic32_evic, "microchip,pic32mzda-evic", pic32_of_init);