[Qemu-devel] [PATCH V2 3/7] introduce dpcd module.

[fred . konrad]

From: KONRAD Frederic <address@hidden>

This introduces a DPCD modules. It wires on a aux-bus and can be accessed by
driver to get lane-speed, etc.

Signed-off-by: KONRAD Frederic <address@hidden>
---
 hw/display/Makefile.objs |   1 +
 hw/display/dpcd.c        | 151 +++++++++++++++++++++++++++++++++++++++++++++++
 hw/display/dpcd.h        |  72 ++++++++++++++++++++++
 3 files changed, 224 insertions(+)
 create mode 100644 hw/display/dpcd.c
 create mode 100644 hw/display/dpcd.h

diff --git a/hw/display/Makefile.objs b/hw/display/Makefile.objs
index 61c80f3..f75094f 100644
--- a/hw/display/Makefile.objs
+++ b/hw/display/Makefile.objs
@@ -36,3 +36,4 @@ obj-$(CONFIG_VGA) += vga.o
 common-obj-$(CONFIG_QXL) += qxl.o qxl-logger.o qxl-render.o
 
 obj-$(CONFIG_VIRTIO) += virtio-gpu.o
+obj-$(CONFIG_XLNX_ZYNQMP) += dpcd.o
diff --git a/hw/display/dpcd.c b/hw/display/dpcd.c
new file mode 100644
index 0000000..b4eeea7
--- /dev/null
+++ b/hw/display/dpcd.c
@@ -0,0 +1,151 @@
+/*
+ * dpcd.c
+ *
+ *  Copyright (C)2015 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: address@hidden
+ *
+ *  Developed by :
+ *  Frederic Konrad   <address@hidden>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option)any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * This is a simple AUX slave which emulates a connected screen.
+ */
+
+#include "hw/aux.h"
+#include "dpcd.h"
+
+#ifndef DEBUG_DPCD
+#define DEBUG_DPCD 0
+#endif
+
+#define DPRINTF(fmt, ...) do {                                                 
\
+    if (DEBUG_DPCD) {                                                          
\
+        qemu_log("dpcd: " fmt, ## __VA_ARGS__);                                
\
+    }                                                                          
\
+} while (0);
+
+#define DPCD_READABLE_AREA                      0x600
+
+struct DPCDState {
+    AUXSlave parent_obj;
+
+    /*
+     * The DCPD is 0x7FFFF length but read as 0 after offset 0x5FF.
+     */
+    uint8_t dpcd_info[DPCD_READABLE_AREA];
+
+    MemoryRegion iomem;
+};
+
+static uint64_t dpcd_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint64_t ret;
+    DPCDState *e = DPCD(opaque);
+
+    if (offset < DPCD_READABLE_AREA) {
+        ret = e->dpcd_info[offset];
+    } else {
+        ret = 0;
+    }
+
+    DPRINTF("read %u @0x%8.8lX\n", (uint8_t)ret, offset);
+    return ret;
+}
+
+static void dpcd_write(void *opaque, hwaddr offset, uint64_t value,
+                       unsigned size)
+{
+    DPCDState *e = DPCD(opaque);
+
+    DPRINTF("write %u @0x%8.8lX\n", (uint8_t)value, offset);
+
+    if (offset < DPCD_READABLE_AREA) {
+        e->dpcd_info[offset] = value;
+    }
+}
+
+static const MemoryRegionOps aux_ops = {
+    .read = dpcd_read,
+    .write = dpcd_write,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 1,
+    },
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 1,
+    },
+};
+
+static void dpcd_reset(DeviceState *dev)
+{
+    DPCDState *s = DPCD(dev);
+    memset(&(s->dpcd_info), 0, sizeof(s->dpcd_info));
+
+    s->dpcd_info[0x00] = DPCD_REV_1_0;
+    s->dpcd_info[0x01] = DPCD_5_4GBPS;
+    s->dpcd_info[0x02] = 0x1;
+    s->dpcd_info[0x08] = DPCD_EDID_PRESENT;
+    s->dpcd_info[0x09] = 0xFF;
+
+    /* CR DONE, CE DONE, SYMBOL LOCKED.. */
+    s->dpcd_info[0x202] = 0x07;
+    /* INTERLANE_ALIGN_DONE.. */
+    s->dpcd_info[0x204] = 0x01;
+    s->dpcd_info[0x205] = 0x01;
+}
+
+static void dpcd_init(Object *obj)
+{
+    DPCDState *s = DPCD(obj);
+
+    memory_region_init_io(&s->iomem, obj, &aux_ops, s, TYPE_DPCD, 0x7FFFF);
+    aux_init_mmio(AUX_SLAVE(obj), &s->iomem);
+}
+
+static const VMStateDescription vmstate_dpcd = {
+    .name = TYPE_DPCD,
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY_V(dpcd_info, DPCDState, DPCD_READABLE_AREA, 0),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void dpcd_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    dc->reset = dpcd_reset;
+    dc->vmsd = &vmstate_dpcd;
+}
+
+static const TypeInfo dpcd_info = {
+    .name          = TYPE_DPCD,
+    .parent        = TYPE_AUX_SLAVE,
+    .instance_size = sizeof(DPCDState),
+    .class_init    = dpcd_class_init,
+    .instance_init = dpcd_init,
+};
+
+static void dpcd_register_types(void)
+{
+    type_register_static(&dpcd_info);
+}
+
+type_init(dpcd_register_types)
diff --git a/hw/display/dpcd.h b/hw/display/dpcd.h
new file mode 100644
index 0000000..57c393b
--- /dev/null
+++ b/hw/display/dpcd.h
@@ -0,0 +1,72 @@
+/*
+ * dpcd.h
+ *
+ *  Copyright (C)2015 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: address@hidden
+ *
+ *  Developed by :
+ *  Frederic Konrad   <address@hidden>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option)any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef DPCD_H
+#define DPCD_H
+
+typedef struct DPCDState DPCDState;
+
+#define TYPE_DPCD "dpcd"
+#define DPCD(obj) OBJECT_CHECK(DPCDState, (obj), TYPE_DPCD)
+
+/* DCPD Revision. */
+#define DPCD_REV_1_0                            0x10
+#define DPCD_REV_1_1                            0x11
+
+/* DCPD Max Link Rate. */
+#define DPCD_1_62GBPS                           0x06
+#define DPCD_2_7GBPS                            0x0A
+#define DPCD_5_4GBPS                            0x14
+
+/* DCPD Max down spread. */
+#define DPCD_UP_TO_0_5                          0x01
+#define DPCD_NO_AUX_HANDSHAKE_LINK_TRAINING     0x40
+
+/* DCPD Downstream port type. */
+#define DPCD_DISPLAY_PORT                       0x00
+#define DPCD_ANALOG                             0x02
+#define DPCD_DVI_HDMI                           0x04
+#define DPCD_OTHER                              0x06
+
+/* DPCD Format conversion. */
+#define DPCD_FORMAT_CONVERSION                  0x08
+
+/* Main link channel coding. */
+#define DPCD_ANSI_8B_10B                        0x01
+
+/* Down stream port count. */
+#define DPCD_OUI_SUPPORTED                      0x80
+
+/* Receiver port capability. */
+#define DPCD_EDID_PRESENT                       0x02
+#define DPCD_ASSOCIATED_TO_PRECEDING_PORT       0x04
+
+/* Down stream port capability. */
+#define DPCD_CAP_DISPLAY_PORT                   0x000
+#define DPCD_CAP_ANALOG_VGA                     0x001
+#define DPCD_CAP_DVI                            0x002
+#define DPCD_CAP_HDMI                           0x003
+#define DPCD_CAP_OTHER                          0x100
+
+#endif /* !DPCD_H */
-- 
1.9.0