xref: /openbmc/qemu/hw/misc/allwinner-a10-dramc.c (revision ffe98631)
1 /*
2  * Allwinner A10 DRAM Controller emulation
3  *
4  * Copyright (C) 2022 Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
5  *
6  *  This file is derived from Allwinner H3 DRAMC,
7  *  by Niek Linnenbank.
8  *
9  * This program is free software: you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation, either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include "qemu/osdep.h"
24 #include "qemu/units.h"
25 #include "hw/sysbus.h"
26 #include "migration/vmstate.h"
27 #include "qemu/log.h"
28 #include "qemu/module.h"
29 #include "hw/misc/allwinner-a10-dramc.h"
30 
31 /* DRAMC register offsets */
32 enum {
33     REG_SDR_CCR = 0x0000,
34     REG_SDR_ZQCR0 = 0x00a8,
35     REG_SDR_ZQSR = 0x00b0
36 };
37 
38 #define REG_INDEX(offset)    (offset / sizeof(uint32_t))
39 
40 /* DRAMC register flags */
41 enum {
42     REG_SDR_CCR_DATA_TRAINING = (1 << 30),
43     REG_SDR_CCR_DRAM_INIT     = (1 << 31),
44 };
45 enum {
46     REG_SDR_ZQSR_ZCAL         = (1 << 31),
47 };
48 
49 /* DRAMC register reset values */
50 enum {
51     REG_SDR_CCR_RESET   = 0x80020000,
52     REG_SDR_ZQCR0_RESET = 0x07b00000,
53     REG_SDR_ZQSR_RESET  = 0x80000000
54 };
55 
56 static uint64_t allwinner_a10_dramc_read(void *opaque, hwaddr offset,
57                                        unsigned size)
58 {
59     const AwA10DramControllerState *s = AW_A10_DRAMC(opaque);
60     const uint32_t idx = REG_INDEX(offset);
61 
62     switch (offset) {
63     case REG_SDR_CCR:
64     case REG_SDR_ZQCR0:
65     case REG_SDR_ZQSR:
66         break;
67     case 0x2e4 ... AW_A10_DRAMC_IOSIZE:
68         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
69                       __func__, (uint32_t)offset);
70         return 0;
71     default:
72         qemu_log_mask(LOG_UNIMP, "%s: unimplemented read offset 0x%04x\n",
73                       __func__, (uint32_t)offset);
74         return 0;
75     }
76 
77     return s->regs[idx];
78 }
79 
80 static void allwinner_a10_dramc_write(void *opaque, hwaddr offset,
81                                    uint64_t val, unsigned size)
82 {
83     AwA10DramControllerState *s = AW_A10_DRAMC(opaque);
84     const uint32_t idx = REG_INDEX(offset);
85 
86     switch (offset) {
87     case REG_SDR_CCR:
88         if (val & REG_SDR_CCR_DRAM_INIT) {
89             /* Clear DRAM_INIT to indicate process is done. */
90             val &= ~REG_SDR_CCR_DRAM_INIT;
91         }
92         if (val & REG_SDR_CCR_DATA_TRAINING) {
93             /* Clear DATA_TRAINING to indicate process is done. */
94             val &= ~REG_SDR_CCR_DATA_TRAINING;
95         }
96         break;
97     case REG_SDR_ZQCR0:
98         /* Set ZCAL in ZQSR to indicate calibration is done. */
99         s->regs[REG_INDEX(REG_SDR_ZQSR)] |= REG_SDR_ZQSR_ZCAL;
100         break;
101     case 0x2e4 ... AW_A10_DRAMC_IOSIZE:
102         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
103                       __func__, (uint32_t)offset);
104         break;
105     default:
106         qemu_log_mask(LOG_UNIMP, "%s: unimplemented write offset 0x%04x\n",
107                       __func__, (uint32_t)offset);
108         break;
109     }
110 
111     s->regs[idx] = (uint32_t) val;
112 }
113 
114 static const MemoryRegionOps allwinner_a10_dramc_ops = {
115     .read = allwinner_a10_dramc_read,
116     .write = allwinner_a10_dramc_write,
117     .endianness = DEVICE_NATIVE_ENDIAN,
118     .valid = {
119         .min_access_size = 4,
120         .max_access_size = 4,
121     },
122     .impl.min_access_size = 4,
123 };
124 
125 static void allwinner_a10_dramc_reset_enter(Object *obj, ResetType type)
126 {
127     AwA10DramControllerState *s = AW_A10_DRAMC(obj);
128 
129     /* Set default values for registers */
130     s->regs[REG_INDEX(REG_SDR_CCR)] = REG_SDR_CCR_RESET;
131     s->regs[REG_INDEX(REG_SDR_ZQCR0)] = REG_SDR_ZQCR0_RESET;
132     s->regs[REG_INDEX(REG_SDR_ZQSR)] = REG_SDR_ZQSR_RESET;
133 }
134 
135 static void allwinner_a10_dramc_init(Object *obj)
136 {
137     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
138     AwA10DramControllerState *s = AW_A10_DRAMC(obj);
139 
140     /* Memory mapping */
141     memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_a10_dramc_ops, s,
142                           TYPE_AW_A10_DRAMC, AW_A10_DRAMC_IOSIZE);
143     sysbus_init_mmio(sbd, &s->iomem);
144 }
145 
146 static const VMStateDescription allwinner_a10_dramc_vmstate = {
147     .name = "allwinner-a10-dramc",
148     .version_id = 1,
149     .minimum_version_id = 1,
150     .fields = (VMStateField[]) {
151         VMSTATE_UINT32_ARRAY(regs, AwA10DramControllerState,
152                              AW_A10_DRAMC_REGS_NUM),
153         VMSTATE_END_OF_LIST()
154     }
155 };
156 
157 static void allwinner_a10_dramc_class_init(ObjectClass *klass, void *data)
158 {
159     DeviceClass *dc = DEVICE_CLASS(klass);
160     ResettableClass *rc = RESETTABLE_CLASS(klass);
161 
162     rc->phases.enter = allwinner_a10_dramc_reset_enter;
163     dc->vmsd = &allwinner_a10_dramc_vmstate;
164 }
165 
166 static const TypeInfo allwinner_a10_dramc_info = {
167     .name          = TYPE_AW_A10_DRAMC,
168     .parent        = TYPE_SYS_BUS_DEVICE,
169     .instance_init = allwinner_a10_dramc_init,
170     .instance_size = sizeof(AwA10DramControllerState),
171     .class_init    = allwinner_a10_dramc_class_init,
172 };
173 
174 static void allwinner_a10_dramc_register(void)
175 {
176     type_register_static(&allwinner_a10_dramc_info);
177 }
178 
179 type_init(allwinner_a10_dramc_register)
180