1 /*
2 * Cristian Birsan <cristian.birsan@microchip.com>
3 * Joshua Henderson <joshua.henderson@microchip.com>
4 * Copyright (C) 2016 Microchip Technology Inc. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/irqdomain.h>
15 #include <linux/of_address.h>
16 #include <linux/slab.h>
17 #include <linux/io.h>
18 #include <linux/irqchip.h>
19 #include <linux/irq.h>
20
21 #include <asm/irq.h>
22 #include <asm/traps.h>
23 #include <asm/mach-pic32/pic32.h>
24
25 #define REG_INTCON 0x0000
26 #define REG_INTSTAT 0x0020
27 #define REG_IFS_OFFSET 0x0040
28 #define REG_IEC_OFFSET 0x00C0
29 #define REG_IPC_OFFSET 0x0140
30 #define REG_OFF_OFFSET 0x0540
31
32 #define MAJPRI_MASK 0x07
33 #define SUBPRI_MASK 0x03
34 #define PRIORITY_MASK 0x1F
35
36 #define PIC32_INT_PRI(pri, subpri) \
37 ((((pri) & MAJPRI_MASK) << 2) | ((subpri) & SUBPRI_MASK))
38
39 struct evic_chip_data {
40 u32 irq_types[NR_IRQS];
41 u32 ext_irqs[8];
42 };
43
44 static struct irq_domain *evic_irq_domain;
45 static void __iomem *evic_base;
46
plat_irq_dispatch(void)47 asmlinkage void __weak plat_irq_dispatch(void)
48 {
49 unsigned int irq, hwirq;
50
51 hwirq = readl(evic_base + REG_INTSTAT) & 0xFF;
52 irq = irq_linear_revmap(evic_irq_domain, hwirq);
53 do_IRQ(irq);
54 }
55
irqd_to_priv(struct irq_data * data)56 static struct evic_chip_data *irqd_to_priv(struct irq_data *data)
57 {
58 return (struct evic_chip_data *)data->domain->host_data;
59 }
60
pic32_set_ext_polarity(int bit,u32 type)61 static int pic32_set_ext_polarity(int bit, u32 type)
62 {
63 /*
64 * External interrupts can be either edge rising or edge falling,
65 * but not both.
66 */
67 switch (type) {
68 case IRQ_TYPE_EDGE_RISING:
69 writel(BIT(bit), evic_base + PIC32_SET(REG_INTCON));
70 break;
71 case IRQ_TYPE_EDGE_FALLING:
72 writel(BIT(bit), evic_base + PIC32_CLR(REG_INTCON));
73 break;
74 default:
75 return -EINVAL;
76 }
77
78 return 0;
79 }
80
pic32_set_type_edge(struct irq_data * data,unsigned int flow_type)81 static int pic32_set_type_edge(struct irq_data *data,
82 unsigned int flow_type)
83 {
84 struct evic_chip_data *priv = irqd_to_priv(data);
85 int ret;
86 int i;
87
88 if (!(flow_type & IRQ_TYPE_EDGE_BOTH))
89 return -EBADR;
90
91 /* set polarity for external interrupts only */
92 for (i = 0; i < ARRAY_SIZE(priv->ext_irqs); i++) {
93 if (priv->ext_irqs[i] == data->hwirq) {
94 ret = pic32_set_ext_polarity(i, flow_type);
95 if (ret)
96 return ret;
97 }
98 }
99
100 irqd_set_trigger_type(data, flow_type);
101
102 return IRQ_SET_MASK_OK;
103 }
104
pic32_bind_evic_interrupt(int irq,int set)105 static void pic32_bind_evic_interrupt(int irq, int set)
106 {
107 writel(set, evic_base + REG_OFF_OFFSET + irq * 4);
108 }
109
pic32_set_irq_priority(int irq,int priority)110 static void pic32_set_irq_priority(int irq, int priority)
111 {
112 u32 reg, shift;
113
114 reg = irq / 4;
115 shift = (irq % 4) * 8;
116
117 writel(PRIORITY_MASK << shift,
118 evic_base + PIC32_CLR(REG_IPC_OFFSET + reg * 0x10));
119 writel(priority << shift,
120 evic_base + PIC32_SET(REG_IPC_OFFSET + reg * 0x10));
121 }
122
123 #define IRQ_REG_MASK(_hwirq, _reg, _mask) \
124 do { \
125 _reg = _hwirq / 32; \
126 _mask = 1 << (_hwirq % 32); \
127 } while (0)
128
pic32_irq_domain_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hw)129 static int pic32_irq_domain_map(struct irq_domain *d, unsigned int virq,
130 irq_hw_number_t hw)
131 {
132 struct evic_chip_data *priv = d->host_data;
133 struct irq_data *data;
134 int ret;
135 u32 iecclr, ifsclr;
136 u32 reg, mask;
137
138 ret = irq_map_generic_chip(d, virq, hw);
139 if (ret)
140 return ret;
141
142 /*
143 * Piggyback on xlate function to move to an alternate chip as necessary
144 * at time of mapping instead of allowing the flow handler/chip to be
145 * changed later. This requires all interrupts to be configured through
146 * DT.
147 */
148 if (priv->irq_types[hw] & IRQ_TYPE_SENSE_MASK) {
149 data = irq_domain_get_irq_data(d, virq);
150 irqd_set_trigger_type(data, priv->irq_types[hw]);
151 irq_setup_alt_chip(data, priv->irq_types[hw]);
152 }
153
154 IRQ_REG_MASK(hw, reg, mask);
155
156 iecclr = PIC32_CLR(REG_IEC_OFFSET + reg * 0x10);
157 ifsclr = PIC32_CLR(REG_IFS_OFFSET + reg * 0x10);
158
159 /* mask and clear flag */
160 writel(mask, evic_base + iecclr);
161 writel(mask, evic_base + ifsclr);
162
163 /* default priority is required */
164 pic32_set_irq_priority(hw, PIC32_INT_PRI(2, 0));
165
166 return ret;
167 }
168
pic32_irq_domain_xlate(struct irq_domain * d,struct device_node * ctrlr,const u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_type)169 int pic32_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
170 const u32 *intspec, unsigned int intsize,
171 irq_hw_number_t *out_hwirq, unsigned int *out_type)
172 {
173 struct evic_chip_data *priv = d->host_data;
174
175 if (WARN_ON(intsize < 2))
176 return -EINVAL;
177
178 if (WARN_ON(intspec[0] >= NR_IRQS))
179 return -EINVAL;
180
181 *out_hwirq = intspec[0];
182 *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
183
184 priv->irq_types[intspec[0]] = intspec[1] & IRQ_TYPE_SENSE_MASK;
185
186 return 0;
187 }
188
189 static const struct irq_domain_ops pic32_irq_domain_ops = {
190 .map = pic32_irq_domain_map,
191 .xlate = pic32_irq_domain_xlate,
192 };
193
pic32_ext_irq_of_init(struct irq_domain * domain)194 static void __init pic32_ext_irq_of_init(struct irq_domain *domain)
195 {
196 struct device_node *node = irq_domain_get_of_node(domain);
197 struct evic_chip_data *priv = domain->host_data;
198 struct property *prop;
199 const __le32 *p;
200 u32 hwirq;
201 int i = 0;
202 const char *pname = "microchip,external-irqs";
203
204 of_property_for_each_u32(node, pname, prop, p, hwirq) {
205 if (i >= ARRAY_SIZE(priv->ext_irqs)) {
206 pr_warn("More than %d external irq, skip rest\n",
207 ARRAY_SIZE(priv->ext_irqs));
208 break;
209 }
210
211 priv->ext_irqs[i] = hwirq;
212 i++;
213 }
214 }
215
pic32_of_init(struct device_node * node,struct device_node * parent)216 static int __init pic32_of_init(struct device_node *node,
217 struct device_node *parent)
218 {
219 struct irq_chip_generic *gc;
220 struct evic_chip_data *priv;
221 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
222 int nchips, ret;
223 int i;
224
225 nchips = DIV_ROUND_UP(NR_IRQS, 32);
226
227 evic_base = of_iomap(node, 0);
228 if (!evic_base)
229 return -ENOMEM;
230
231 priv = kcalloc(nchips, sizeof(*priv), GFP_KERNEL);
232 if (!priv) {
233 ret = -ENOMEM;
234 goto err_iounmap;
235 }
236
237 evic_irq_domain = irq_domain_add_linear(node, nchips * 32,
238 &pic32_irq_domain_ops,
239 priv);
240 if (!evic_irq_domain) {
241 ret = -ENOMEM;
242 goto err_free_priv;
243 }
244
245 /*
246 * The PIC32 EVIC has a linear list of irqs and the type of each
247 * irq is determined by the hardware peripheral the EVIC is arbitrating.
248 * These irq types are defined in the datasheet as "persistent" and
249 * "non-persistent" which are mapped here to level and edge
250 * respectively. To manage the different flow handler requirements of
251 * each irq type, different chip_types are used.
252 */
253 ret = irq_alloc_domain_generic_chips(evic_irq_domain, 32, 2,
254 "evic-level", handle_level_irq,
255 clr, 0, 0);
256 if (ret)
257 goto err_domain_remove;
258
259 board_bind_eic_interrupt = &pic32_bind_evic_interrupt;
260
261 for (i = 0; i < nchips; i++) {
262 u32 ifsclr = PIC32_CLR(REG_IFS_OFFSET + (i * 0x10));
263 u32 iec = REG_IEC_OFFSET + (i * 0x10);
264
265 gc = irq_get_domain_generic_chip(evic_irq_domain, i * 32);
266
267 gc->reg_base = evic_base;
268 gc->unused = 0;
269
270 /*
271 * Level/persistent interrupts have a special requirement that
272 * the condition generating the interrupt be cleared before the
273 * interrupt flag (ifs) can be cleared. chip.irq_eoi is used to
274 * complete the interrupt with an ack.
275 */
276 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
277 gc->chip_types[0].handler = handle_fasteoi_irq;
278 gc->chip_types[0].regs.ack = ifsclr;
279 gc->chip_types[0].regs.mask = iec;
280 gc->chip_types[0].chip.name = "evic-level";
281 gc->chip_types[0].chip.irq_eoi = irq_gc_ack_set_bit;
282 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
283 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
284 gc->chip_types[0].chip.flags = IRQCHIP_SKIP_SET_WAKE;
285
286 /* Edge interrupts */
287 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
288 gc->chip_types[1].handler = handle_edge_irq;
289 gc->chip_types[1].regs.ack = ifsclr;
290 gc->chip_types[1].regs.mask = iec;
291 gc->chip_types[1].chip.name = "evic-edge";
292 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
293 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
294 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
295 gc->chip_types[1].chip.irq_set_type = pic32_set_type_edge;
296 gc->chip_types[1].chip.flags = IRQCHIP_SKIP_SET_WAKE;
297
298 gc->private = &priv[i];
299 }
300
301 irq_set_default_host(evic_irq_domain);
302
303 /*
304 * External interrupts have software configurable edge polarity. These
305 * interrupts are defined in DT allowing polarity to be configured only
306 * for these interrupts when requested.
307 */
308 pic32_ext_irq_of_init(evic_irq_domain);
309
310 return 0;
311
312 err_domain_remove:
313 irq_domain_remove(evic_irq_domain);
314
315 err_free_priv:
316 kfree(priv);
317
318 err_iounmap:
319 iounmap(evic_base);
320
321 return ret;
322 }
323
324 IRQCHIP_DECLARE(pic32_evic, "microchip,pic32mzda-evic", pic32_of_init);
325