hw/sd: Add Cadence SDHCI emulation

Cadence SD/SDIO/eMMC Host Controller (SD4HC) is an SDHCI compatible
controller. The SDHCI compatible registers start from offset 0x200,
which are called Slot Register Set (SRS) in its datasheet.

This creates a Cadence SDHCI model built on top of the existing
generic SDHCI model. Cadence specific Host Register Set (HRS) is
implemented to make guest software happy.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Acked-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <1598924352-89526-8-git-send-email-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

3 files changed, 198 insertions, 0 deletions

diff --git a/hw/sd/Kconfig b/hw/sd/Kconfig
index c5e1e55..633b9af 100644
--- a/hw/sd/Kconfig
+++ b/hw/sd/Kconfig
@@ -19,3 +19,7 @@ config SDHCI_PCI
     default y if PCI_DEVICES
     depends on PCI
     select SDHCI
+
+config CADENCE_SDHCI
+    bool
+    select SDHCI
diff --git a/hw/sd/cadence_sdhci.c b/hw/sd/cadence_sdhci.c
new file mode 100644
index 0000000..0b371c8
--- /dev/null
+++ b/hw/sd/cadence_sdhci.c
@@ -0,0 +1,193 @@
+/*
+ * Cadence SDHCI emulation
+ *
+ * Copyright (c) 2020 Wind River Systems, Inc.
+ *
+ * Author:
+ *   Bin Meng <bin.meng@windriver.com>
+ *
+ * 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 or
+ * (at your option) version 3 of the License.
+ *
+ * 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/bitops.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "migration/vmstate.h"
+#include "hw/irq.h"
+#include "hw/sd/cadence_sdhci.h"
+#include "sdhci-internal.h"
+
+/* HRS - Host Register Set (specific to Cadence) */
+
+#define CADENCE_SDHCI_HRS00             0x00    /* general information */
+#define CADENCE_SDHCI_HRS00_SWR             BIT(0)
+#define CADENCE_SDHCI_HRS00_POR_VAL         0x00010000
+
+#define CADENCE_SDHCI_HRS04             0x10    /* PHY access port */
+#define CADENCE_SDHCI_HRS04_WR              BIT(24)
+#define CADENCE_SDHCI_HRS04_RD              BIT(25)
+#define CADENCE_SDHCI_HRS04_ACK             BIT(26)
+
+#define CADENCE_SDHCI_HRS06             0x18    /* eMMC control */
+#define CADENCE_SDHCI_HRS06_TUNE_UP         BIT(15)
+
+/* SRS - Slot Register Set (SDHCI-compatible) */
+
+#define CADENCE_SDHCI_SRS_BASE          0x200
+
+#define TO_REG(addr)    ((addr) / sizeof(uint32_t))
+
+static void cadence_sdhci_instance_init(Object *obj)
+{
+    CadenceSDHCIState *s = CADENCE_SDHCI(obj);
+
+    object_initialize_child(OBJECT(s), "generic-sdhci",
+                            &s->sdhci, TYPE_SYSBUS_SDHCI);
+}
+
+static void cadence_sdhci_reset(DeviceState *dev)
+{
+    CadenceSDHCIState *s = CADENCE_SDHCI(dev);
+
+    memset(s->regs, 0, CADENCE_SDHCI_REG_SIZE);
+    s->regs[TO_REG(CADENCE_SDHCI_HRS00)] = CADENCE_SDHCI_HRS00_POR_VAL;
+
+    device_cold_reset(DEVICE(&s->sdhci));
+}
+
+static uint64_t cadence_sdhci_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    CadenceSDHCIState *s = opaque;
+    uint32_t val;
+
+    val = s->regs[TO_REG(addr)];
+
+    return (uint64_t)val;
+}
+
+static void cadence_sdhci_write(void *opaque, hwaddr addr, uint64_t val,
+                                unsigned int size)
+{
+    CadenceSDHCIState *s = opaque;
+    uint32_t val32 = (uint32_t)val;
+
+    switch (addr) {
+    case CADENCE_SDHCI_HRS00:
+        /*
+         * The only writable bit is SWR (software reset) and it automatically
+         * clears to zero, so essentially this register remains unchanged.
+         */
+        if (val32 & CADENCE_SDHCI_HRS00_SWR) {
+            cadence_sdhci_reset(DEVICE(s));
+        }
+
+        break;
+    case CADENCE_SDHCI_HRS04:
+        /*
+         * Only emulate the ACK bit behavior when read or write transaction
+         * are requested.
+         */
+        if (val32 & (CADENCE_SDHCI_HRS04_WR | CADENCE_SDHCI_HRS04_RD)) {
+            val32 |= CADENCE_SDHCI_HRS04_ACK;
+        } else {
+            val32 &= ~CADENCE_SDHCI_HRS04_ACK;
+        }
+
+        s->regs[TO_REG(addr)] = val32;
+        break;
+    case CADENCE_SDHCI_HRS06:
+        if (val32 & CADENCE_SDHCI_HRS06_TUNE_UP) {
+            val32 &= ~CADENCE_SDHCI_HRS06_TUNE_UP;
+        }
+
+        s->regs[TO_REG(addr)] = val32;
+        break;
+    default:
+        s->regs[TO_REG(addr)] = val32;
+        break;
+    }
+}
+
+static const MemoryRegionOps cadence_sdhci_ops = {
+    .read = cadence_sdhci_read,
+    .write = cadence_sdhci_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    }
+};
+
+static void cadence_sdhci_realize(DeviceState *dev, Error **errp)
+{
+    CadenceSDHCIState *s = CADENCE_SDHCI(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+    SysBusDevice *sbd_sdhci = SYS_BUS_DEVICE(&s->sdhci);
+
+    memory_region_init(&s->container, OBJECT(s),
+                       "cadence.sdhci-container", 0x1000);
+    sysbus_init_mmio(sbd, &s->container);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &cadence_sdhci_ops,
+                          s, TYPE_CADENCE_SDHCI, CADENCE_SDHCI_REG_SIZE);
+    memory_region_add_subregion(&s->container, 0, &s->iomem);
+
+    sysbus_realize(sbd_sdhci, errp);
+    memory_region_add_subregion(&s->container, CADENCE_SDHCI_SRS_BASE,
+                                sysbus_mmio_get_region(sbd_sdhci, 0));
+
+    /* propagate irq and "sd-bus" from generic-sdhci */
+    sysbus_pass_irq(sbd, sbd_sdhci);
+    s->bus = qdev_get_child_bus(DEVICE(sbd_sdhci), "sd-bus");
+}
+
+static const VMStateDescription vmstate_cadence_sdhci = {
+    .name = TYPE_CADENCE_SDHCI,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, CadenceSDHCIState, CADENCE_SDHCI_NUM_REGS),
+        VMSTATE_END_OF_LIST(),
+    },
+};
+
+static void cadence_sdhci_class_init(ObjectClass *classp, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(classp);
+
+    dc->desc = "Cadence SD/SDIO/eMMC Host Controller (SD4HC)";
+    dc->realize = cadence_sdhci_realize;
+    dc->reset = cadence_sdhci_reset;
+    dc->vmsd = &vmstate_cadence_sdhci;
+}
+
+static TypeInfo cadence_sdhci_info = {
+    .name          = TYPE_CADENCE_SDHCI,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(CadenceSDHCIState),
+    .instance_init = cadence_sdhci_instance_init,
+    .class_init    = cadence_sdhci_class_init,
+};
+
+static void cadence_sdhci_register_types(void)
+{
+    type_register_static(&cadence_sdhci_info);
+}
+
+type_init(cadence_sdhci_register_types)
diff --git a/hw/sd/meson.build b/hw/sd/meson.build
index b43e59b..9c29691 100644
--- a/hw/sd/meson.build
+++ b/hw/sd/meson.build
@@ -10,3 +10,4 @@ softmmu_ss.add(when: 'CONFIG_PXA2XX', if_true: files('pxa2xx_mmci.c'))
 softmmu_ss.add(when: 'CONFIG_RASPI', if_true: files('bcm2835_sdhost.c'))
 softmmu_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('aspeed_sdhci.c'))
 softmmu_ss.add(when: 'CONFIG_ALLWINNER_H3', if_true: files('allwinner-sdhost.c'))
+softmmu_ss.add(when: 'CONFIG_CADENCE_SDHCI', if_true: files('cadence_sdhci.c'))