xref: /openbmc/qemu/hw/misc/stm32_rcc.c (revision ca5aa28e)
1 /*
2  * STM32 RCC (only reset and enable registers are implemented)
3  *
4  * Copyright (c) 2024 Román Cárdenas <rcardenas.rod@gmail.com>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
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/stm32_rcc.h"
31 
32 static void stm32_rcc_reset(DeviceState *dev)
33 {
34     STM32RccState *s = STM32_RCC(dev);
35 
36     for (int i = 0; i < STM32_RCC_NREGS; i++) {
37         s->regs[i] = 0;
38     }
39 }
40 
41 static uint64_t stm32_rcc_read(void *opaque, hwaddr addr, unsigned int size)
42 {
43     STM32RccState *s = STM32_RCC(opaque);
44 
45     uint32_t value = 0;
46     if (addr > STM32_RCC_DCKCFGR2) {
47         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%"HWADDR_PRIx"\n",
48                       __func__, addr);
49     } else {
50         value = s->regs[addr >> 2];
51     }
52     trace_stm32_rcc_read(addr, value);
53     return value;
54 }
55 
56 static void stm32_rcc_write(void *opaque, hwaddr addr,
57                             uint64_t val64, unsigned int size)
58 {
59     STM32RccState *s = STM32_RCC(opaque);
60     uint32_t value = val64;
61     uint32_t prev_value, new_value, irq_offset;
62 
63     trace_stm32_rcc_write(value, addr);
64 
65     if (addr > STM32_RCC_DCKCFGR2) {
66         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%"HWADDR_PRIx"\n",
67                       __func__, addr);
68         return;
69     }
70 
71     switch (addr) {
72     case STM32_RCC_AHB1_RSTR...STM32_RCC_APB2_RSTR:
73         prev_value = s->regs[addr / 4];
74         s->regs[addr / 4] = value;
75 
76         irq_offset = ((addr - STM32_RCC_AHB1_RSTR) / 4) * 32;
77         for (int i = 0; i < 32; i++) {
78             new_value = extract32(value, i, 1);
79             if (extract32(prev_value, i, 1) && !new_value) {
80                 trace_stm32_rcc_pulse_reset(irq_offset + i, new_value);
81                 qemu_set_irq(s->reset_irq[irq_offset + i], new_value);
82             }
83         }
84         return;
85     case STM32_RCC_AHB1_ENR...STM32_RCC_APB2_ENR:
86         prev_value = s->regs[addr / 4];
87         s->regs[addr / 4] = value;
88 
89         irq_offset = ((addr - STM32_RCC_AHB1_ENR) / 4) * 32;
90         for (int i = 0; i < 32; i++) {
91             new_value = extract32(value, i, 1);
92             if (!extract32(prev_value, i, 1) && new_value) {
93                 trace_stm32_rcc_pulse_enable(irq_offset + i, new_value);
94                 qemu_set_irq(s->enable_irq[irq_offset + i], new_value);
95             }
96         }
97         return;
98     default:
99         qemu_log_mask(
100             LOG_UNIMP,
101             "%s: The RCC peripheral only supports enable and reset in QEMU\n",
102             __func__
103         );
104         s->regs[addr >> 2] = value;
105     }
106 }
107 
108 static const MemoryRegionOps stm32_rcc_ops = {
109     .read = stm32_rcc_read,
110     .write = stm32_rcc_write,
111     .endianness = DEVICE_NATIVE_ENDIAN,
112 };
113 
114 static void stm32_rcc_init(Object *obj)
115 {
116     STM32RccState *s = STM32_RCC(obj);
117 
118     memory_region_init_io(&s->mmio, obj, &stm32_rcc_ops, s,
119                           TYPE_STM32_RCC, STM32_RCC_PERIPHERAL_SIZE);
120     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
121 
122     qdev_init_gpio_out(DEVICE(obj), s->reset_irq, STM32_RCC_NIRQS);
123     qdev_init_gpio_out(DEVICE(obj), s->enable_irq, STM32_RCC_NIRQS);
124 
125     for (int i = 0; i < STM32_RCC_NIRQS; i++) {
126         sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->reset_irq[i]);
127         sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->enable_irq[i]);
128     }
129 }
130 
131 static const VMStateDescription vmstate_stm32_rcc = {
132     .name = TYPE_STM32_RCC,
133     .version_id = 1,
134     .minimum_version_id = 1,
135     .fields = (const VMStateField[]) {
136         VMSTATE_UINT32_ARRAY(regs, STM32RccState, STM32_RCC_NREGS),
137         VMSTATE_END_OF_LIST()
138     }
139 };
140 
141 static void stm32_rcc_class_init(ObjectClass *klass, void *data)
142 {
143     DeviceClass *dc = DEVICE_CLASS(klass);
144 
145     dc->vmsd = &vmstate_stm32_rcc;
146     device_class_set_legacy_reset(dc, stm32_rcc_reset);
147 }
148 
149 static const TypeInfo stm32_rcc_info = {
150     .name          = TYPE_STM32_RCC,
151     .parent        = TYPE_SYS_BUS_DEVICE,
152     .instance_size = sizeof(STM32RccState),
153     .instance_init = stm32_rcc_init,
154     .class_init    = stm32_rcc_class_init,
155 };
156 
157 static void stm32_rcc_register_types(void)
158 {
159     type_register_static(&stm32_rcc_info);
160 }
161 
162 type_init(stm32_rcc_register_types)
163