xref: /openbmc/qemu/hw/misc/stm32l4x5_exti.c (revision 5f69e42d)
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_NUM_GPIO_EVENT_IN_LINES 16
46 #define EXTI_MAX_IRQ_PER_BANK 32
47 #define EXTI_IRQS_BANK0  32
48 #define EXTI_IRQS_BANK1  8
49 
50 static const unsigned irqs_per_bank[EXTI_NUM_REGISTER] = {
51     EXTI_IRQS_BANK0,
52     EXTI_IRQS_BANK1,
53 };
54 
55 static const uint32_t exti_romask[EXTI_NUM_REGISTER] = {
56     0xff820000, /* 0b11111111_10000010_00000000_00000000 */
57     0x00000087, /* 0b00000000_00000000_00000000_10000111 */
58 };
59 
60 static unsigned regbank_index_by_irq(unsigned irq)
61 {
62     return irq >= EXTI_MAX_IRQ_PER_BANK ? 1 : 0;
63 }
64 
65 static unsigned regbank_index_by_addr(hwaddr addr)
66 {
67     return addr >= EXTI_IMR2 ? 1 : 0;
68 }
69 
70 static unsigned valid_mask(unsigned bank)
71 {
72     return MAKE_64BIT_MASK(0, irqs_per_bank[bank]);
73 }
74 
75 static unsigned configurable_mask(unsigned bank)
76 {
77     return valid_mask(bank) & ~exti_romask[bank];
78 }
79 
80 static void stm32l4x5_exti_reset_hold(Object *obj, ResetType type)
81 {
82     Stm32l4x5ExtiState *s = STM32L4X5_EXTI(obj);
83 
84     for (unsigned bank = 0; bank < EXTI_NUM_REGISTER; bank++) {
85         s->imr[bank] = exti_romask[bank];
86         s->emr[bank] = 0x00000000;
87         s->rtsr[bank] = 0x00000000;
88         s->ftsr[bank] = 0x00000000;
89         s->swier[bank] = 0x00000000;
90         s->pr[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 the interrupt is masked, pr won't be raised */
106     if (!extract32(s->imr[bank], irq, 1)) {
107         return;
108     }
109 
110     if (((1 << irq) & s->rtsr[bank]) && level) {
111         /* Rising Edge */
112         s->pr[bank] |= 1 << irq;
113         qemu_irq_pulse(s->irq[oirq]);
114     } else if (((1 << irq) & s->ftsr[bank]) && !level) {
115         /* Falling Edge */
116         s->pr[bank] |= 1 << irq;
117         qemu_irq_pulse(s->irq[oirq]);
118     }
119     /*
120      * In the following situations :
121      * - falling edge but rising trigger selected
122      * - rising edge but falling trigger selected
123      * - no trigger selected
124      * No action is required
125      */
126 }
127 
128 static uint64_t stm32l4x5_exti_read(void *opaque, hwaddr addr,
129                                     unsigned int size)
130 {
131     Stm32l4x5ExtiState *s = opaque;
132     uint32_t r = 0;
133     const unsigned bank = regbank_index_by_addr(addr);
134 
135     switch (addr) {
136     case EXTI_IMR1:
137     case EXTI_IMR2:
138         r = s->imr[bank];
139         break;
140     case EXTI_EMR1:
141     case EXTI_EMR2:
142         r = s->emr[bank];
143         break;
144     case EXTI_RTSR1:
145     case EXTI_RTSR2:
146         r = s->rtsr[bank];
147         break;
148     case EXTI_FTSR1:
149     case EXTI_FTSR2:
150         r = s->ftsr[bank];
151         break;
152     case EXTI_SWIER1:
153     case EXTI_SWIER2:
154         r = s->swier[bank];
155         break;
156     case EXTI_PR1:
157     case EXTI_PR2:
158         r = s->pr[bank];
159         break;
160 
161     default:
162         qemu_log_mask(LOG_GUEST_ERROR,
163                       "STM32L4X5_exti_read: Bad offset 0x%" HWADDR_PRIx "\n",
164                       addr);
165         break;
166     }
167 
168     trace_stm32l4x5_exti_read(addr, r);
169 
170     return r;
171 }
172 
173 static void stm32l4x5_exti_write(void *opaque, hwaddr addr,
174                                  uint64_t val64, unsigned int size)
175 {
176     Stm32l4x5ExtiState *s = opaque;
177     const unsigned bank = regbank_index_by_addr(addr);
178 
179     trace_stm32l4x5_exti_write(addr, val64);
180 
181     switch (addr) {
182     case EXTI_IMR1:
183     case EXTI_IMR2:
184         s->imr[bank] = val64 & valid_mask(bank);
185         return;
186     case EXTI_EMR1:
187     case EXTI_EMR2:
188         s->emr[bank] = val64 & valid_mask(bank);
189         return;
190     case EXTI_RTSR1:
191     case EXTI_RTSR2:
192         s->rtsr[bank] = val64 & configurable_mask(bank);
193         return;
194     case EXTI_FTSR1:
195     case EXTI_FTSR2:
196         s->ftsr[bank] = val64 & configurable_mask(bank);
197         return;
198     case EXTI_SWIER1:
199     case EXTI_SWIER2: {
200         const uint32_t set = val64 & configurable_mask(bank);
201         const uint32_t pend = set & ~s->swier[bank] & s->imr[bank] &
202                               ~s->pr[bank];
203         s->swier[bank] = set;
204         s->pr[bank] |= pend;
205         for (unsigned i = 0; i < irqs_per_bank[bank]; i++) {
206             if (extract32(pend, i, 1)) {
207                 qemu_irq_pulse(s->irq[i + 32 * bank]);
208             }
209         }
210         return;
211     }
212     case EXTI_PR1:
213     case EXTI_PR2: {
214         const uint32_t cleared = s->pr[bank] & val64 & configurable_mask(bank);
215         /* This bit is cleared by writing a 1 to it */
216         s->pr[bank] &= ~cleared;
217         /* Software triggered interrupts are cleared as well */
218         s->swier[bank] &= ~cleared;
219         return;
220     }
221     default:
222         qemu_log_mask(LOG_GUEST_ERROR,
223                       "STM32L4X5_exti_write: Bad offset 0x%" HWADDR_PRIx "\n",
224                       addr);
225     }
226 }
227 
228 static const MemoryRegionOps stm32l4x5_exti_ops = {
229     .read = stm32l4x5_exti_read,
230     .write = stm32l4x5_exti_write,
231     .endianness = DEVICE_NATIVE_ENDIAN,
232     .impl.min_access_size = 4,
233     .impl.max_access_size = 4,
234     .impl.unaligned = false,
235     .valid.min_access_size = 4,
236     .valid.max_access_size = 4,
237     .valid.unaligned = false,
238 };
239 
240 static void stm32l4x5_exti_init(Object *obj)
241 {
242     Stm32l4x5ExtiState *s = STM32L4X5_EXTI(obj);
243 
244     for (size_t i = 0; i < EXTI_NUM_INTERRUPT_OUT_LINES; i++) {
245         sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq[i]);
246     }
247 
248     memory_region_init_io(&s->mmio, obj, &stm32l4x5_exti_ops, s,
249                           TYPE_STM32L4X5_EXTI, 0x400);
250     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
251 
252     qdev_init_gpio_in(DEVICE(obj), stm32l4x5_exti_set_irq,
253                       EXTI_NUM_GPIO_EVENT_IN_LINES);
254 }
255 
256 static const VMStateDescription vmstate_stm32l4x5_exti = {
257     .name = TYPE_STM32L4X5_EXTI,
258     .version_id = 1,
259     .minimum_version_id = 1,
260     .fields = (VMStateField[]) {
261         VMSTATE_UINT32_ARRAY(imr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
262         VMSTATE_UINT32_ARRAY(emr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
263         VMSTATE_UINT32_ARRAY(rtsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
264         VMSTATE_UINT32_ARRAY(ftsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
265         VMSTATE_UINT32_ARRAY(swier, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
266         VMSTATE_UINT32_ARRAY(pr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
267         VMSTATE_END_OF_LIST()
268     }
269 };
270 
271 static void stm32l4x5_exti_class_init(ObjectClass *klass, void *data)
272 {
273     DeviceClass *dc = DEVICE_CLASS(klass);
274     ResettableClass *rc = RESETTABLE_CLASS(klass);
275 
276     dc->vmsd = &vmstate_stm32l4x5_exti;
277     rc->phases.hold = stm32l4x5_exti_reset_hold;
278 }
279 
280 static const TypeInfo stm32l4x5_exti_types[] = {
281     {
282         .name          = TYPE_STM32L4X5_EXTI,
283         .parent        = TYPE_SYS_BUS_DEVICE,
284         .instance_size = sizeof(Stm32l4x5ExtiState),
285         .instance_init = stm32l4x5_exti_init,
286         .class_init    = stm32l4x5_exti_class_init,
287     }
288 };
289 
290 DEFINE_TYPES(stm32l4x5_exti_types)
291