xref: /openbmc/qemu/hw/misc/stm32l4x5_exti.c (revision e8f62689)
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         s->irq_levels[bank] = 0x00000000;
92     }
93 }
94 
95 static void stm32l4x5_exti_set_irq(void *opaque, int irq, int level)
96 {
97     Stm32l4x5ExtiState *s = opaque;
98     const unsigned bank = regbank_index_by_irq(irq);
99     const int oirq = irq;
100 
101     trace_stm32l4x5_exti_set_irq(irq, level);
102 
103     /* Shift the value to enable access in x2 registers. */
104     irq %= EXTI_MAX_IRQ_PER_BANK;
105 
106     if (level == extract32(s->irq_levels[bank], irq, 1)) {
107         /* No change in IRQ line state: do nothing */
108         return;
109     }
110     s->irq_levels[bank] = deposit32(s->irq_levels[bank], irq, 1, level);
111 
112     /* If the interrupt is masked, pr won't be raised */
113     if (!extract32(s->imr[bank], irq, 1)) {
114         return;
115     }
116 
117     if ((level && extract32(s->rtsr[bank], irq, 1)) ||
118         (!level && extract32(s->ftsr[bank], irq, 1))) {
119 
120         s->pr[bank] |= 1 << irq;
121         qemu_irq_pulse(s->irq[oirq]);
122     }
123 }
124 
125 static uint64_t stm32l4x5_exti_read(void *opaque, hwaddr addr,
126                                     unsigned int size)
127 {
128     Stm32l4x5ExtiState *s = opaque;
129     uint32_t r = 0;
130     const unsigned bank = regbank_index_by_addr(addr);
131 
132     switch (addr) {
133     case EXTI_IMR1:
134     case EXTI_IMR2:
135         r = s->imr[bank];
136         break;
137     case EXTI_EMR1:
138     case EXTI_EMR2:
139         r = s->emr[bank];
140         break;
141     case EXTI_RTSR1:
142     case EXTI_RTSR2:
143         r = s->rtsr[bank];
144         break;
145     case EXTI_FTSR1:
146     case EXTI_FTSR2:
147         r = s->ftsr[bank];
148         break;
149     case EXTI_SWIER1:
150     case EXTI_SWIER2:
151         r = s->swier[bank];
152         break;
153     case EXTI_PR1:
154     case EXTI_PR2:
155         r = s->pr[bank];
156         break;
157 
158     default:
159         qemu_log_mask(LOG_GUEST_ERROR,
160                       "STM32L4X5_exti_read: Bad offset 0x%" HWADDR_PRIx "\n",
161                       addr);
162         break;
163     }
164 
165     trace_stm32l4x5_exti_read(addr, r);
166 
167     return r;
168 }
169 
170 static void stm32l4x5_exti_write(void *opaque, hwaddr addr,
171                                  uint64_t val64, unsigned int size)
172 {
173     Stm32l4x5ExtiState *s = opaque;
174     const unsigned bank = regbank_index_by_addr(addr);
175 
176     trace_stm32l4x5_exti_write(addr, val64);
177 
178     switch (addr) {
179     case EXTI_IMR1:
180     case EXTI_IMR2:
181         s->imr[bank] = val64 & valid_mask(bank);
182         return;
183     case EXTI_EMR1:
184     case EXTI_EMR2:
185         s->emr[bank] = val64 & valid_mask(bank);
186         return;
187     case EXTI_RTSR1:
188     case EXTI_RTSR2:
189         s->rtsr[bank] = val64 & configurable_mask(bank);
190         return;
191     case EXTI_FTSR1:
192     case EXTI_FTSR2:
193         s->ftsr[bank] = val64 & configurable_mask(bank);
194         return;
195     case EXTI_SWIER1:
196     case EXTI_SWIER2: {
197         const uint32_t set = val64 & configurable_mask(bank);
198         const uint32_t pend = set & ~s->swier[bank] & s->imr[bank] &
199                               ~s->pr[bank];
200         s->swier[bank] = set;
201         s->pr[bank] |= pend;
202         for (unsigned i = 0; i < irqs_per_bank[bank]; i++) {
203             if (extract32(pend, i, 1)) {
204                 qemu_irq_pulse(s->irq[i + 32 * bank]);
205             }
206         }
207         return;
208     }
209     case EXTI_PR1:
210     case EXTI_PR2: {
211         const uint32_t cleared = s->pr[bank] & val64 & configurable_mask(bank);
212         /* This bit is cleared by writing a 1 to it */
213         s->pr[bank] &= ~cleared;
214         /* Software triggered interrupts are cleared as well */
215         s->swier[bank] &= ~cleared;
216         return;
217     }
218     default:
219         qemu_log_mask(LOG_GUEST_ERROR,
220                       "STM32L4X5_exti_write: Bad offset 0x%" HWADDR_PRIx "\n",
221                       addr);
222     }
223 }
224 
225 static const MemoryRegionOps stm32l4x5_exti_ops = {
226     .read = stm32l4x5_exti_read,
227     .write = stm32l4x5_exti_write,
228     .endianness = DEVICE_NATIVE_ENDIAN,
229     .impl.min_access_size = 4,
230     .impl.max_access_size = 4,
231     .impl.unaligned = false,
232     .valid.min_access_size = 4,
233     .valid.max_access_size = 4,
234     .valid.unaligned = false,
235 };
236 
237 static void stm32l4x5_exti_init(Object *obj)
238 {
239     Stm32l4x5ExtiState *s = STM32L4X5_EXTI(obj);
240 
241     for (size_t i = 0; i < EXTI_NUM_INTERRUPT_OUT_LINES; i++) {
242         sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq[i]);
243     }
244 
245     memory_region_init_io(&s->mmio, obj, &stm32l4x5_exti_ops, s,
246                           TYPE_STM32L4X5_EXTI, 0x400);
247     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
248 
249     qdev_init_gpio_in(DEVICE(obj), stm32l4x5_exti_set_irq,
250                       EXTI_NUM_GPIO_EVENT_IN_LINES);
251 }
252 
253 static const VMStateDescription vmstate_stm32l4x5_exti = {
254     .name = TYPE_STM32L4X5_EXTI,
255     .version_id = 2,
256     .minimum_version_id = 2,
257     .fields = (VMStateField[]) {
258         VMSTATE_UINT32_ARRAY(imr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
259         VMSTATE_UINT32_ARRAY(emr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
260         VMSTATE_UINT32_ARRAY(rtsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
261         VMSTATE_UINT32_ARRAY(ftsr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
262         VMSTATE_UINT32_ARRAY(swier, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
263         VMSTATE_UINT32_ARRAY(pr, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
264         VMSTATE_UINT32_ARRAY(irq_levels, Stm32l4x5ExtiState, EXTI_NUM_REGISTER),
265         VMSTATE_END_OF_LIST()
266     }
267 };
268 
269 static void stm32l4x5_exti_class_init(ObjectClass *klass, void *data)
270 {
271     DeviceClass *dc = DEVICE_CLASS(klass);
272     ResettableClass *rc = RESETTABLE_CLASS(klass);
273 
274     dc->vmsd = &vmstate_stm32l4x5_exti;
275     rc->phases.hold = stm32l4x5_exti_reset_hold;
276 }
277 
278 static const TypeInfo stm32l4x5_exti_types[] = {
279     {
280         .name          = TYPE_STM32L4X5_EXTI,
281         .parent        = TYPE_SYS_BUS_DEVICE,
282         .instance_size = sizeof(Stm32l4x5ExtiState),
283         .instance_init = stm32l4x5_exti_init,
284         .class_init    = stm32l4x5_exti_class_init,
285     }
286 };
287 
288 DEFINE_TYPES(stm32l4x5_exti_types)
289