xref: /openbmc/qemu/hw/misc/stm32l4x5_exti.c (revision 514d3035)
1 /*
2  * STM32L4x5 EXTI (Extended interrupts and events controller)
3  *
4  * Copyright (c) 2023 Arnaud Minier <arnaud.minier@telecom-paris.fr>
5  * Copyright (c) 2023 Samuel Tardieu <samuel.tardieu@telecom-paris.fr>
6  * Copyright (c) 2023 Inès Varhol <ines.varhol@telecom-paris.fr>
7  *
8  * SPDX-License-Identifier: GPL-2.0-or-later
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  *
13  * This work is based on the stm32f4xx_exti by Alistair Francis.
14  * Original code is licensed under the MIT License:
15  *
16  * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
17  */
18 
19 /*
20  * The reference used is the STMicroElectronics RM0351 Reference manual
21  * for STM32L4x5 and STM32L4x6 advanced Arm ® -based 32-bit MCUs.
22  * https://www.st.com/en/microcontrollers-microprocessors/stm32l4x5/documentation.html
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/log.h"
27 #include "trace.h"
28 #include "hw/irq.h"
29 #include "migration/vmstate.h"
30 #include "hw/misc/stm32l4x5_exti.h"
31 
32 #define EXTI_IMR1   0x00
33 #define EXTI_EMR1   0x04
34 #define EXTI_RTSR1  0x08
35 #define EXTI_FTSR1  0x0C
36 #define EXTI_SWIER1 0x10
37 #define EXTI_PR1    0x14
38 #define EXTI_IMR2   0x20
39 #define EXTI_EMR2   0x24
40 #define EXTI_RTSR2  0x28
41 #define EXTI_FTSR2  0x2C
42 #define EXTI_SWIER2 0x30
43 #define EXTI_PR2    0x34
44 
45 #define EXTI_MAX_IRQ_PER_BANK 32
46 #define EXTI_IRQS_BANK0  32
47 #define EXTI_IRQS_BANK1  8
48 
49 static const unsigned irqs_per_bank[EXTI_NUM_REGISTER] = {
50     EXTI_IRQS_BANK0,
51     EXTI_IRQS_BANK1,
52 };
53 
54 static const uint32_t exti_romask[EXTI_NUM_REGISTER] = {
55     0xff820000, /* 0b11111111_10000010_00000000_00000000 */
56     0x00000087, /* 0b00000000_00000000_00000000_10000111 */
57 };
58 
59 static unsigned regbank_index_by_irq(unsigned irq)
60 {
61     return irq >= EXTI_MAX_IRQ_PER_BANK ? 1 : 0;
62 }
63 
64 static unsigned regbank_index_by_addr(hwaddr addr)
65 {
66     return addr >= EXTI_IMR2 ? 1 : 0;
67 }
68 
69 static unsigned valid_mask(unsigned bank)
70 {
71     return MAKE_64BIT_MASK(0, irqs_per_bank[bank]);
72 }
73 
74 static unsigned configurable_mask(unsigned bank)
75 {
76     return valid_mask(bank) & ~exti_romask[bank];
77 }
78 
79 static void stm32l4x5_exti_reset_hold(Object *obj, ResetType type)
80 {
81     Stm32l4x5ExtiState *s = STM32L4X5_EXTI(obj);
82 
83     for (unsigned bank = 0; bank < EXTI_NUM_REGISTER; bank++) {
84         s->imr[bank] = exti_romask[bank];
85         s->emr[bank] = 0x00000000;
86         s->rtsr[bank] = 0x00000000;
87         s->ftsr[bank] = 0x00000000;
88         s->swier[bank] = 0x00000000;
89         s->pr[bank] = 0x00000000;
90         s->irq_levels[bank] = 0x00000000;
91     }
92 }
93 
94 static void stm32l4x5_exti_set_irq(void *opaque, int irq, int level)
95 {
96     Stm32l4x5ExtiState *s = opaque;
97     const unsigned bank = regbank_index_by_irq(irq);
98     const int oirq = irq;
99 
100     trace_stm32l4x5_exti_set_irq(irq, level);
101 
102     /* Shift the value to enable access in x2 registers. */
103     irq %= EXTI_MAX_IRQ_PER_BANK;
104 
105     if (level == extract32(s->irq_levels[bank], irq, 1)) {
106         /* No change in IRQ line state: do nothing */
107         return;
108     }
109     s->irq_levels[bank] = deposit32(s->irq_levels[bank], irq, 1, level);
110 
111     /* If the interrupt is masked, pr won't be raised */
112     if (!extract32(s->imr[bank], irq, 1)) {
113         return;
114     }
115 
116     /* In case of a direct line interrupt */
117     if (extract32(exti_romask[bank], irq, 1)) {
118         qemu_set_irq(s->irq[oirq], level);
119         return;
120     }
121 
122     /* In case of a configurable interrupt */
123     if ((level && extract32(s->rtsr[bank], irq, 1)) ||
124         (!level && extract32(s->ftsr[bank], irq, 1))) {
125 
126         s->pr[bank] |= 1 << irq;
127         qemu_irq_pulse(s->irq[oirq]);
128     }
129 }
130 
131 static uint64_t stm32l4x5_exti_read(void *opaque, hwaddr addr,
132                                     unsigned int size)
133 {
134     Stm32l4x5ExtiState *s = opaque;
135     uint32_t r = 0;
136     const unsigned bank = regbank_index_by_addr(addr);
137 
138     switch (addr) {
139     case EXTI_IMR1:
140     case EXTI_IMR2:
141         r = s->imr[bank];
142         break;
143     case EXTI_EMR1:
144     case EXTI_EMR2:
145         r = s->emr[bank];
146         break;
147     case EXTI_RTSR1:
148     case EXTI_RTSR2:
149         r = s->rtsr[bank];
150         break;
151     case EXTI_FTSR1:
152     case EXTI_FTSR2:
153         r = s->ftsr[bank];
154         break;
155     case EXTI_SWIER1:
156     case EXTI_SWIER2:
157         r = s->swier[bank];
158         break;
159     case EXTI_PR1:
160     case EXTI_PR2:
161         r = s->pr[bank];
162         break;
163 
164     default:
165         qemu_log_mask(LOG_GUEST_ERROR,
166                       "STM32L4X5_exti_read: Bad offset 0x%" HWADDR_PRIx "\n",
167                       addr);
168         break;
169     }
170 
171     trace_stm32l4x5_exti_read(addr, r);
172 
173     return r;
174 }
175 
176 static void stm32l4x5_exti_write(void *opaque, hwaddr addr,
177                                  uint64_t val64, unsigned int size)
178 {
179     Stm32l4x5ExtiState *s = opaque;
180     const unsigned bank = regbank_index_by_addr(addr);
181 
182     trace_stm32l4x5_exti_write(addr, val64);
183 
184     switch (addr) {
185     case EXTI_IMR1:
186     case EXTI_IMR2:
187         s->imr[bank] = val64 & valid_mask(bank);
188         return;
189     case EXTI_EMR1:
190     case EXTI_EMR2:
191         s->emr[bank] = val64 & valid_mask(bank);
192         return;
193     case EXTI_RTSR1:
194     case EXTI_RTSR2:
195         s->rtsr[bank] = val64 & configurable_mask(bank);
196         return;
197     case EXTI_FTSR1:
198     case EXTI_FTSR2:
199         s->ftsr[bank] = val64 & configurable_mask(bank);
200         return;
201     case EXTI_SWIER1:
202     case EXTI_SWIER2: {
203         const uint32_t set = val64 & configurable_mask(bank);
204         const uint32_t pend = set & ~s->swier[bank] & s->imr[bank] &
205                               ~s->pr[bank];
206         s->swier[bank] = set;
207         s->pr[bank] |= pend;
208         for (unsigned i = 0; i < irqs_per_bank[bank]; i++) {
209             if (extract32(pend, i, 1)) {
210                 qemu_irq_pulse(s->irq[i + 32 * bank]);
211             }
212         }
213         return;
214     }
215     case EXTI_PR1:
216     case EXTI_PR2: {
217         const uint32_t cleared = s->pr[bank] & val64 & configurable_mask(bank);
218         /* This bit is cleared by writing a 1 to it */
219         s->pr[bank] &= ~cleared;
220         /* Software triggered interrupts are cleared as well */
221         s->swier[bank] &= ~cleared;
222         return;
223     }
224     default:
225         qemu_log_mask(LOG_GUEST_ERROR,
226                       "STM32L4X5_exti_write: Bad offset 0x%" HWADDR_PRIx "\n",
227                       addr);
228     }
229 }
230 
231 static const MemoryRegionOps stm32l4x5_exti_ops = {
232     .read = stm32l4x5_exti_read,
233     .write = stm32l4x5_exti_write,
234     .endianness = DEVICE_NATIVE_ENDIAN,
235     .impl.min_access_size = 4,
236     .impl.max_access_size = 4,
237     .impl.unaligned = false,
238     .valid.min_access_size = 4,
239     .valid.max_access_size = 4,
240     .valid.unaligned = false,
241 };
242 
243 static void stm32l4x5_exti_init(Object *obj)
244 {
245     Stm32l4x5ExtiState *s = STM32L4X5_EXTI(obj);
246 
247     for (size_t i = 0; i < EXTI_NUM_LINES; i++) {
248         sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq[i]);
249     }
250 
251     memory_region_init_io(&s->mmio, obj, &stm32l4x5_exti_ops, s,
252                           TYPE_STM32L4X5_EXTI, 0x400);
253     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
254 
255     qdev_init_gpio_in(DEVICE(obj), stm32l4x5_exti_set_irq, EXTI_NUM_LINES);
256 }
257 
258 static const VMStateDescription vmstate_stm32l4x5_exti = {
259     .name = TYPE_STM32L4X5_EXTI,
260     .version_id = 2,
261     .minimum_version_id = 2,
262     .fields = (VMStateField[]) {
263         VMSTATE_UINT32_ARRAY(imr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
264         VMSTATE_UINT32_ARRAY(emr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
265         VMSTATE_UINT32_ARRAY(rtsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
266         VMSTATE_UINT32_ARRAY(ftsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
267         VMSTATE_UINT32_ARRAY(swier, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
268         VMSTATE_UINT32_ARRAY(pr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
269         VMSTATE_UINT32_ARRAY(irq_levels, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
270         VMSTATE_END_OF_LIST()
271     }
272 };
273 
274 static void stm32l4x5_exti_class_init(ObjectClass *klass, void *data)
275 {
276     DeviceClass *dc = DEVICE_CLASS(klass);
277     ResettableClass *rc = RESETTABLE_CLASS(klass);
278 
279     dc->vmsd = &vmstate_stm32l4x5_exti;
280     rc->phases.hold = stm32l4x5_exti_reset_hold;
281 }
282 
283 static const TypeInfo stm32l4x5_exti_types[] = {
284     {
285         .name          = TYPE_STM32L4X5_EXTI,
286         .parent        = TYPE_SYS_BUS_DEVICE,
287         .instance_size = sizeof(Stm32l4x5ExtiState),
288         .instance_init = stm32l4x5_exti_init,
289         .class_init    = stm32l4x5_exti_class_init,
290     }
291 };
292 
293 DEFINE_TYPES(stm32l4x5_exti_types)
294