xref: /openbmc/qemu/hw/misc/mchp_pfsoc_sysreg.c (revision a6caeee8)
1 /*
2  * Microchip PolarFire SoC SYSREG module emulation
3  *
4  * Copyright (c) 2020 Wind River Systems, Inc.
5  *
6  * Author:
7  *   Bin Meng <bin.meng@windriver.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 or
12  * (at your option) version 3 of the License.
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 along
20  * with this program; if not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include "qemu/osdep.h"
24 #include "qemu/bitops.h"
25 #include "qemu/log.h"
26 #include "qapi/error.h"
27 #include "hw/sysbus.h"
28 #include "hw/misc/mchp_pfsoc_sysreg.h"
29 
30 #define ENVM_CR         0xb8
31 
32 static uint64_t mchp_pfsoc_sysreg_read(void *opaque, hwaddr offset,
33                                        unsigned size)
34 {
35     uint32_t val = 0;
36 
37     switch (offset) {
38     case ENVM_CR:
39         /* Indicate the eNVM is running at the configured divider rate */
40         val = BIT(6);
41         break;
42     default:
43         qemu_log_mask(LOG_UNIMP, "%s: unimplemented device read "
44                       "(size %d, offset 0x%" HWADDR_PRIx ")\n",
45                       __func__, size, offset);
46         break;
47     }
48 
49     return val;
50 }
51 
52 static void mchp_pfsoc_sysreg_write(void *opaque, hwaddr offset,
53                                     uint64_t value, unsigned size)
54 {
55     qemu_log_mask(LOG_UNIMP, "%s: unimplemented device write "
56                   "(size %d, value 0x%" PRIx64
57                   ", offset 0x%" HWADDR_PRIx ")\n",
58                   __func__, size, value, offset);
59 }
60 
61 static const MemoryRegionOps mchp_pfsoc_sysreg_ops = {
62     .read = mchp_pfsoc_sysreg_read,
63     .write = mchp_pfsoc_sysreg_write,
64     .endianness = DEVICE_LITTLE_ENDIAN,
65 };
66 
67 static void mchp_pfsoc_sysreg_realize(DeviceState *dev, Error **errp)
68 {
69     MchpPfSoCSysregState *s = MCHP_PFSOC_SYSREG(dev);
70 
71     memory_region_init_io(&s->sysreg, OBJECT(dev),
72                           &mchp_pfsoc_sysreg_ops, s,
73                           "mchp.pfsoc.sysreg",
74                           MCHP_PFSOC_SYSREG_REG_SIZE);
75     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->sysreg);
76 }
77 
78 static void mchp_pfsoc_sysreg_class_init(ObjectClass *klass, void *data)
79 {
80     DeviceClass *dc = DEVICE_CLASS(klass);
81 
82     dc->desc = "Microchip PolarFire SoC SYSREG module";
83     dc->realize = mchp_pfsoc_sysreg_realize;
84 }
85 
86 static const TypeInfo mchp_pfsoc_sysreg_info = {
87     .name          = TYPE_MCHP_PFSOC_SYSREG,
88     .parent        = TYPE_SYS_BUS_DEVICE,
89     .instance_size = sizeof(MchpPfSoCSysregState),
90     .class_init    = mchp_pfsoc_sysreg_class_init,
91 };
92 
93 static void mchp_pfsoc_sysreg_register_types(void)
94 {
95     type_register_static(&mchp_pfsoc_sysreg_info);
96 }
97 
98 type_init(mchp_pfsoc_sysreg_register_types)
99