xref: /openbmc/qemu/hw/misc/allwinner-sramc.c (revision 8d7f954a)
1 /*
2  * Allwinner R40 SRAM controller emulation
3  *
4  * Copyright (C) 2023 qianfan Zhao <qianfanguijin@163.com>
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/units.h"
22 #include "hw/sysbus.h"
23 #include "migration/vmstate.h"
24 #include "qemu/log.h"
25 #include "qemu/module.h"
26 #include "qapi/error.h"
27 #include "hw/qdev-properties.h"
28 #include "hw/qdev-properties-system.h"
29 #include "hw/misc/allwinner-sramc.h"
30 #include "trace.h"
31 
32 /*
33  * register offsets
34  * https://linux-sunxi.org/SRAM_Controller_Register_Guide
35  */
36 enum {
37     REG_SRAM_CTL1_CFG               = 0x04, /* SRAM Control register 1 */
38     REG_SRAM_VER                    = 0x24, /* SRAM Version register */
39     REG_SRAM_R40_SOFT_ENTRY_REG0    = 0xbc,
40 };
41 
42 /* REG_SRAMC_VERSION bit defines */
43 #define SRAM_VER_READ_ENABLE            (1 << 15)
44 #define SRAM_VER_VERSION_SHIFT          16
45 #define SRAM_VERSION_SUN8I_R40          0x1701
46 
47 static uint64_t allwinner_sramc_read(void *opaque, hwaddr offset,
48                                      unsigned size)
49 {
50     AwSRAMCState *s = AW_SRAMC(opaque);
51     AwSRAMCClass *sc = AW_SRAMC_GET_CLASS(s);
52     uint64_t val = 0;
53 
54     switch (offset) {
55     case REG_SRAM_CTL1_CFG:
56         val = s->sram_ctl1;
57         break;
58     case REG_SRAM_VER:
59         /* bit15: lock bit, set this bit before reading this register */
60         if (s->sram_ver & SRAM_VER_READ_ENABLE) {
61             val = SRAM_VER_READ_ENABLE |
62                     (sc->sram_version_code << SRAM_VER_VERSION_SHIFT);
63         }
64         break;
65     case REG_SRAM_R40_SOFT_ENTRY_REG0:
66         val = s->sram_soft_entry_reg0;
67         break;
68     default:
69         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
70                       __func__, (uint32_t)offset);
71         return 0;
72     }
73 
74     trace_allwinner_sramc_read(offset, val);
75 
76     return val;
77 }
78 
79 static void allwinner_sramc_write(void *opaque, hwaddr offset,
80                                   uint64_t val, unsigned size)
81 {
82     AwSRAMCState *s = AW_SRAMC(opaque);
83 
84     trace_allwinner_sramc_write(offset, val);
85 
86     switch (offset) {
87     case REG_SRAM_CTL1_CFG:
88         s->sram_ctl1 = val;
89         break;
90     case REG_SRAM_VER:
91         /* Only the READ_ENABLE bit is writeable */
92         s->sram_ver = val & SRAM_VER_READ_ENABLE;
93         break;
94     case REG_SRAM_R40_SOFT_ENTRY_REG0:
95         s->sram_soft_entry_reg0 = val;
96         break;
97     default:
98         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
99                       __func__, (uint32_t)offset);
100         break;
101     }
102 }
103 
104 static const MemoryRegionOps allwinner_sramc_ops = {
105     .read = allwinner_sramc_read,
106     .write = allwinner_sramc_write,
107     .endianness = DEVICE_NATIVE_ENDIAN,
108     .valid = {
109         .min_access_size = 4,
110         .max_access_size = 4,
111     },
112     .impl.min_access_size = 4,
113 };
114 
115 static const VMStateDescription allwinner_sramc_vmstate = {
116     .name = "allwinner-sramc",
117     .version_id = 1,
118     .minimum_version_id = 1,
119     .fields = (VMStateField[]) {
120         VMSTATE_UINT32(sram_ver, AwSRAMCState),
121         VMSTATE_UINT32(sram_soft_entry_reg0, AwSRAMCState),
122         VMSTATE_END_OF_LIST()
123     }
124 };
125 
126 static void allwinner_sramc_reset(DeviceState *dev)
127 {
128     AwSRAMCState *s = AW_SRAMC(dev);
129     AwSRAMCClass *sc = AW_SRAMC_GET_CLASS(s);
130 
131     switch (sc->sram_version_code) {
132     case SRAM_VERSION_SUN8I_R40:
133         s->sram_ctl1 = 0x1300;
134         break;
135     }
136 }
137 
138 static void allwinner_sramc_class_init(ObjectClass *klass, void *data)
139 {
140     DeviceClass *dc = DEVICE_CLASS(klass);
141 
142     dc->reset = allwinner_sramc_reset;
143     dc->vmsd = &allwinner_sramc_vmstate;
144 }
145 
146 static void allwinner_sramc_init(Object *obj)
147 {
148     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
149     AwSRAMCState *s = AW_SRAMC(obj);
150 
151     /* Memory mapping */
152     memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_sramc_ops, s,
153                            TYPE_AW_SRAMC, 1 * KiB);
154     sysbus_init_mmio(sbd, &s->iomem);
155 }
156 
157 static const TypeInfo allwinner_sramc_info = {
158     .name          = TYPE_AW_SRAMC,
159     .parent        = TYPE_SYS_BUS_DEVICE,
160     .instance_init = allwinner_sramc_init,
161     .instance_size = sizeof(AwSRAMCState),
162     .class_init    = allwinner_sramc_class_init,
163 };
164 
165 static void allwinner_r40_sramc_class_init(ObjectClass *klass, void *data)
166 {
167     AwSRAMCClass *sc = AW_SRAMC_CLASS(klass);
168 
169     sc->sram_version_code = SRAM_VERSION_SUN8I_R40;
170 }
171 
172 static const TypeInfo allwinner_r40_sramc_info = {
173     .name          = TYPE_AW_SRAMC_SUN8I_R40,
174     .parent        = TYPE_AW_SRAMC,
175     .class_init    = allwinner_r40_sramc_class_init,
176 };
177 
178 static void allwinner_sramc_register(void)
179 {
180     type_register_static(&allwinner_sramc_info);
181     type_register_static(&allwinner_r40_sramc_info);
182 }
183 
184 type_init(allwinner_sramc_register)
185