hw/sd: Add QOM bus which SD cards plug in to

Add a QOM bus for SD cards to plug in to.

Note that since sd_enable() is used only by one board and there
only as part of a broken implementation, we do not provide it in
the SDBus API (but instead add a warning comment about the old
function). Whoever converts OMAP and the nseries boards to QOM
will need to either implement the card switch properly or move
the enable hack into the OMAP MMC controller model.

In the SDBus API, the old-style use of sd_set_cb to register some
qemu_irqs for notification of card insertion and write-protect
toggling is replaced with methods in the SDBusClass which the
card calls on status changes and methods in the SDClass which
the controller can call to find out the current status. The
query methods will allow us to remove the abuse of the 'register
irqs' API by controllers in their reset methods to trigger
the card to tell them about the current status again.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 1455646193-13238-5-git-send-email-peter.maydell@linaro.org

3 files changed, 190 insertions, 5 deletions

diff --git a/hw/sd/Makefile.objs b/hw/sd/Makefile.objs
index f1aed83d9d..31c83308f2 100644
--- a/hw/sd/Makefile.objs
+++ b/hw/sd/Makefile.objs
@@ -1,6 +1,6 @@
 common-obj-$(CONFIG_PL181) += pl181.o
 common-obj-$(CONFIG_SSI_SD) += ssi-sd.o
-common-obj-$(CONFIG_SD) += sd.o
+common-obj-$(CONFIG_SD) += sd.o core.o
 common-obj-$(CONFIG_SDHCI) += sdhci.o
 
 obj-$(CONFIG_MILKYMIST) += milkymist-memcard.o
diff --git a/hw/sd/core.c b/hw/sd/core.c
new file mode 100644
index 0000000000..14c2bdf27b
--- /dev/null
+++ b/hw/sd/core.c
@@ -0,0 +1,146 @@
+/*
+ * SD card bus interface code.
+ *
+ * Copyright (c) 2015 Linaro Limited
+ *
+ * Author:
+ *  Peter Maydell <peter.maydell@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/qdev-core.h"
+#include "sysemu/block-backend.h"
+#include "hw/sd/sd.h"
+
+static SDState *get_card(SDBus *sdbus)
+{
+    /* We only ever have one child on the bus so just return it */
+    BusChild *kid = QTAILQ_FIRST(&sdbus->qbus.children);
+
+    if (!kid) {
+        return NULL;
+    }
+    return SD_CARD(kid->child);
+}
+
+int sdbus_do_command(SDBus *sdbus, SDRequest *req, uint8_t *response)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        return sc->do_command(card, req, response);
+    }
+
+    return 0;
+}
+
+void sdbus_write_data(SDBus *sdbus, uint8_t value)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        sc->write_data(card, value);
+    }
+}
+
+uint8_t sdbus_read_data(SDBus *sdbus)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        return sc->read_data(card);
+    }
+
+    return 0;
+}
+
+bool sdbus_data_ready(SDBus *sdbus)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        return sc->data_ready(card);
+    }
+
+    return false;
+}
+
+bool sdbus_get_inserted(SDBus *sdbus)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        return sc->get_inserted(card);
+    }
+
+    return false;
+}
+
+bool sdbus_get_readonly(SDBus *sdbus)
+{
+    SDState *card = get_card(sdbus);
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        return sc->get_readonly(card);
+    }
+
+    return false;
+}
+
+void sdbus_set_inserted(SDBus *sdbus, bool inserted)
+{
+    SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
+    BusState *qbus = BUS(sdbus);
+
+    if (sbc->set_inserted) {
+        sbc->set_inserted(qbus->parent, inserted);
+    }
+}
+
+void sdbus_set_readonly(SDBus *sdbus, bool readonly)
+{
+    SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
+    BusState *qbus = BUS(sdbus);
+
+    if (sbc->set_readonly) {
+        sbc->set_readonly(qbus->parent, readonly);
+    }
+}
+
+static const TypeInfo sd_bus_info = {
+    .name = TYPE_SD_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(SDBus),
+    .class_size = sizeof(SDBusClass),
+};
+
+static void sd_bus_register_types(void)
+{
+    type_register_static(&sd_bus_info);
+}
+
+type_init(sd_bus_register_types)
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index edd4c82f6f..8902cd818d 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -30,6 +30,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/qdev.h"
 #include "hw/hw.h"
 #include "sysemu/block-backend.h"
 #include "hw/sd/sd.h"
@@ -431,14 +432,41 @@ static void sd_reset(DeviceState *dev)
     sd->expecting_acmd = false;
 }
 
+static bool sd_get_inserted(SDState *sd)
+{
+    return blk_is_inserted(sd->blk);
+}
+
+static bool sd_get_readonly(SDState *sd)
+{
+    return sd->wp_switch;
+}
+
 static void sd_cardchange(void *opaque, bool load)
 {
     SDState *sd = opaque;
+    DeviceState *dev = DEVICE(sd);
+    SDBus *sdbus = SD_BUS(qdev_get_parent_bus(dev));
+    bool inserted = sd_get_inserted(sd);
+    bool readonly = sd_get_readonly(sd);
 
-    qemu_set_irq(sd->inserted_cb, blk_is_inserted(sd->blk));
-    if (blk_is_inserted(sd->blk)) {
-        sd_reset(DEVICE(sd));
-        qemu_set_irq(sd->readonly_cb, sd->wp_switch);
+    if (inserted) {
+        sd_reset(dev);
+    }
+
+    /* The IRQ notification is for legacy non-QOM SD controller devices;
+     * QOMified controllers use the SDBus APIs.
+     */
+    if (sdbus) {
+        sdbus_set_inserted(sdbus, inserted);
+        if (inserted) {
+            sdbus_set_readonly(sdbus, readonly);
+        }
+    } else {
+        qemu_set_irq(sd->inserted_cb, inserted);
+        if (inserted) {
+            qemu_set_irq(sd->readonly_cb, readonly);
+        }
     }
 }
 
@@ -1803,17 +1831,28 @@ static Property sd_properties[] = {
 static void sd_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
+    SDCardClass *sc = SD_CARD_CLASS(klass);
 
     dc->realize = sd_realize;
     dc->props = sd_properties;
     dc->vmsd = &sd_vmstate;
     dc->reset = sd_reset;
+    dc->bus_type = TYPE_SD_BUS;
+
+    sc->do_command = sd_do_command;
+    sc->write_data = sd_write_data;
+    sc->read_data = sd_read_data;
+    sc->data_ready = sd_data_ready;
+    sc->enable = sd_enable;
+    sc->get_inserted = sd_get_inserted;
+    sc->get_readonly = sd_get_readonly;
 }
 
 static const TypeInfo sd_info = {
     .name = TYPE_SD_CARD,
     .parent = TYPE_DEVICE,
     .instance_size = sizeof(SDState),
+    .class_size = sizeof(SDCardClass),
     .class_init = sd_class_init,
     .instance_init = sd_instance_init,
 };