hw/display/dpcd.c

   1 /*
   2  * dpcd.c
   3  *
   4  *  Copyright (C) 2015 : GreenSocs Ltd
   5  *      http://www.greensocs.com/ , email: [email protected]
   6  *
   7  *  Developed by :
   8  *  Frederic Konrad   <[email protected]>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation, either version 2 of the License, or
  13  * (at your option)any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, see <http://www.gnu.org/licenses/>.
  22  *
  23  */
  24
  25 /*
  26  * This is a simple AUX slave which emulates a connected screen.
  27  */
  28
  29 #include "qemu/osdep.h"
  30 #include "qemu/log.h"
  31 #include "hw/misc/auxbus.h"
  32 #include "hw/display/dpcd.h"
  33
  34 #ifndef DEBUG_DPCD
  35 #define DEBUG_DPCD 0
  36 #endif
  37
  38 #define DPRINTF(fmt, ...) do {                                                 \
  39     if (DEBUG_DPCD) {                                                          \
  40         qemu_log("dpcd: " fmt, ## __VA_ARGS__);                                \
  41     }                                                                          \
  42 } while (0)
  43
  44 #define DPCD_READABLE_AREA                      0x600
  45
  46 struct DPCDState {
  47     /*< private >*/
  48     AUXSlave parent_obj;
  49
  50     /*< public >*/
  51     /*
  52      * The DCPD is 0x7FFFF length but read as 0 after offset 0x5FF.
  53      */
  54     uint8_t dpcd_info[DPCD_READABLE_AREA];
  55
  56     MemoryRegion iomem;
  57 };
  58
  59 static uint64_t dpcd_read(void *opaque, hwaddr offset, unsigned size)
  60 {
  61     uint8_t ret;
  62     DPCDState *e = DPCD(opaque);
  63
  64     if (offset < DPCD_READABLE_AREA) {
  65         ret = e->dpcd_info[offset];
  66     } else {
  67         qemu_log_mask(LOG_GUEST_ERROR, "dpcd: Bad offset 0x%" HWADDR_PRIX "\n",
  68                                        offset);
  69         ret = 0;
  70     }
  71
  72     DPRINTF("read 0x%" PRIX8 " @0x%" HWADDR_PRIX "\n", ret, offset);
  73     return ret;
  74 }
  75
  76 static void dpcd_write(void *opaque, hwaddr offset, uint64_t value,
  77                        unsigned size)
  78 {
  79     DPCDState *e = DPCD(opaque);
  80
  81     DPRINTF("write 0x%" PRIX8 " @0x%" HWADDR_PRIX "\n", (uint8_t)value, offset);
  82
  83     if (offset < DPCD_READABLE_AREA) {
  84         e->dpcd_info[offset] = value;
  85     } else {
  86         qemu_log_mask(LOG_GUEST_ERROR, "dpcd: Bad offset 0x%" HWADDR_PRIX "\n",
  87                                        offset);
  88     }
  89 }
  90
  91 static const MemoryRegionOps aux_ops = {
  92     .read = dpcd_read,
  93     .write = dpcd_write,
  94     .valid = {
  95         .min_access_size = 1,
  96         .max_access_size = 1,
  97     },
  98     .impl = {
  99         .min_access_size = 1,
 100         .max_access_size = 1,
 101     },
 102 };
 103
 104 static void dpcd_reset(DeviceState *dev)
 105 {
 106     DPCDState *s = DPCD(dev);
 107
 108     memset(&(s->dpcd_info), 0, sizeof(s->dpcd_info));
 109
 110     s->dpcd_info[DPCD_REVISION] = DPCD_REV_1_0;
 111     s->dpcd_info[DPCD_MAX_LINK_RATE] = DPCD_5_4GBPS;
 112     s->dpcd_info[DPCD_MAX_LANE_COUNT] = DPCD_FOUR_LANES;
 113     s->dpcd_info[DPCD_RECEIVE_PORT0_CAP_0] = DPCD_EDID_PRESENT;
 114     /* buffer size */
 115     s->dpcd_info[DPCD_RECEIVE_PORT0_CAP_1] = 0xFF;
 116
 117     s->dpcd_info[DPCD_LANE0_1_STATUS] = DPCD_LANE0_CR_DONE
 118                                       | DPCD_LANE0_CHANNEL_EQ_DONE
 119                                       | DPCD_LANE0_SYMBOL_LOCKED
 120                                       | DPCD_LANE1_CR_DONE
 121                                       | DPCD_LANE1_CHANNEL_EQ_DONE
 122                                       | DPCD_LANE1_SYMBOL_LOCKED;
 123     s->dpcd_info[DPCD_LANE2_3_STATUS] = DPCD_LANE2_CR_DONE
 124                                       | DPCD_LANE2_CHANNEL_EQ_DONE
 125                                       | DPCD_LANE2_SYMBOL_LOCKED
 126                                       | DPCD_LANE3_CR_DONE
 127                                       | DPCD_LANE3_CHANNEL_EQ_DONE
 128                                       | DPCD_LANE3_SYMBOL_LOCKED;
 129
 130     s->dpcd_info[DPCD_LANE_ALIGN_STATUS_UPDATED] = DPCD_INTERLANE_ALIGN_DONE;
 131     s->dpcd_info[DPCD_SINK_STATUS] = DPCD_RECEIVE_PORT_0_STATUS;
 132 }
 133
 134 static void dpcd_init(Object *obj)
 135 {
 136     DPCDState *s = DPCD(obj);
 137
 138     memory_region_init_io(&s->iomem, obj, &aux_ops, s, TYPE_DPCD, 0x7FFFF);
 139     aux_init_mmio(AUX_SLAVE(obj), &s->iomem);
 140 }
 141
 142 static const VMStateDescription vmstate_dpcd = {
 143     .name = TYPE_DPCD,
 144     .version_id = 0,
 145     .minimum_version_id = 0,
 146     .fields = (VMStateField[]) {
 147         VMSTATE_UINT8_ARRAY_V(dpcd_info, DPCDState, DPCD_READABLE_AREA, 0),
 148         VMSTATE_END_OF_LIST()
 149     }
 150 };
 151
 152 static void dpcd_class_init(ObjectClass *oc, void *data)
 153 {
 154     DeviceClass *dc = DEVICE_CLASS(oc);
 155
 156     dc->reset = dpcd_reset;
 157     dc->vmsd = &vmstate_dpcd;
 158 }
 159
 160 static const TypeInfo dpcd_info = {
 161     .name          = TYPE_DPCD,
 162     .parent        = TYPE_AUX_SLAVE,
 163     .instance_size = sizeof(DPCDState),
 164     .class_init    = dpcd_class_init,
 165     .instance_init = dpcd_init,
 166 };
 167
 168 static void dpcd_register_types(void)
 169 {
 170     type_register_static(&dpcd_info);
 171 }
 172
 173 type_init(dpcd_register_types)