From: Gaurav Sharma <gaurav.sharma_7@nxp.com>

It enables emulation of SD/MMC cards through a virtual SDHCI interface
The emulated SDHCI controller allows guest OS to use emulated storage as
a standard block device.
This will allow running the images such as those generated
by Buildroot.

Reviewed-by: Philippe Mathieu-Daude <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Bernhard Beschow <shentey@gmail.com>
Signed-off-by: Gaurav Sharma <gaurav.sharma_7@nxp.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/Kconfig              |  1 +
 hw/arm/fsl-imx8mm.c         | 25 +++++++++++++++++++++++++
 hw/arm/imx8mm-evk.c         | 17 +++++++++++++++++
 include/hw/arm/fsl-imx8mm.h |  7 +++++++
 4 files changed, 50 insertions(+)

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 26dc3e6ed1..74e8c431a2 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -623,6 +623,7 @@ config FSL_IMX8MM
     select FSL_IMX8MP_ANALOG
     select FSL_IMX8MP_CCM
     select IMX
+    select SDHCI
 
 config FSL_IMX8MM_EVK
     bool
diff --git a/hw/arm/fsl-imx8mm.c b/hw/arm/fsl-imx8mm.c
index 8999bc701e..2a4d4d5e6d 100644
--- a/hw/arm/fsl-imx8mm.c
+++ b/hw/arm/fsl-imx8mm.c
@@ -180,6 +180,10 @@ static void fsl_imx8mm_init(Object *obj)
         object_initialize_child(obj, name, &s->uart[i], TYPE_IMX_SERIAL);
     }
 
+    for (i = 0; i < FSL_IMX8MM_NUM_USDHCS; i++) {
+        g_autofree char *name = g_strdup_printf("usdhc%d", i + 1);
+        object_initialize_child(obj, name, &s->usdhc[i], TYPE_IMX_USDHC);
+    }
 }
 
 static void fsl_imx8mm_realize(DeviceState *dev, Error **errp)
@@ -357,6 +361,26 @@ static void fsl_imx8mm_realize(DeviceState *dev, Error **errp)
                                 fsl_imx8mm_memmap[FSL_IMX8MM_OCRAM].addr,
                                 &s->ocram);
 
+    /* USDHCs */
+    for (i = 0; i < FSL_IMX8MM_NUM_USDHCS; i++) {
+        static const struct {
+            hwaddr addr;
+            unsigned int irq;
+        } usdhc_table[FSL_IMX8MM_NUM_USDHCS] = {
+            { fsl_imx8mm_memmap[FSL_IMX8MM_USDHC1].addr, FSL_IMX8MM_USDHC1_IRQ },
+            { fsl_imx8mm_memmap[FSL_IMX8MM_USDHC2].addr, FSL_IMX8MM_USDHC2_IRQ },
+            { fsl_imx8mm_memmap[FSL_IMX8MM_USDHC3].addr, FSL_IMX8MM_USDHC3_IRQ },
+        };
+
+        if (!sysbus_realize(SYS_BUS_DEVICE(&s->usdhc[i]), errp)) {
+            return;
+        }
+
+        sysbus_mmio_map(SYS_BUS_DEVICE(&s->usdhc[i]), 0, usdhc_table[i].addr);
+        sysbus_connect_irq(SYS_BUS_DEVICE(&s->usdhc[i]), 0,
+                           qdev_get_gpio_in(gicdev, usdhc_table[i].irq));
+    }
+
     /* SNVS */
     if (!sysbus_realize(SYS_BUS_DEVICE(&s->snvs), errp)) {
         return;
@@ -375,6 +399,7 @@ static void fsl_imx8mm_realize(DeviceState *dev, Error **errp)
         case FSL_IMX8MM_OCRAM:
         case FSL_IMX8MM_SNVS_HP:
         case FSL_IMX8MM_UART1 ... FSL_IMX8MM_UART4:
+        case FSL_IMX8MM_USDHC1 ... FSL_IMX8MM_USDHC3:
             /* device implemented and treated above */
             break;
 
diff --git a/hw/arm/imx8mm-evk.c b/hw/arm/imx8mm-evk.c
index 0a8cce8866..dfdf3cd4f8 100644
--- a/hw/arm/imx8mm-evk.c
+++ b/hw/arm/imx8mm-evk.c
@@ -84,6 +84,23 @@ static void imx8mm_evk_init(MachineState *machine)
     memory_region_add_subregion(get_system_memory(), FSL_IMX8MM_RAM_START,
                                 machine->ram);
 
+    for (int i = 0; i < FSL_IMX8MM_NUM_USDHCS; i++) {
+        BusState *bus;
+        DeviceState *carddev;
+        BlockBackend *blk;
+        DriveInfo *di = drive_get(IF_SD, i, 0);
+
+        if (!di) {
+            continue;
+        }
+
+        blk = blk_by_legacy_dinfo(di);
+        bus = qdev_get_child_bus(DEVICE(&s->usdhc[i]), "sd-bus");
+        carddev = qdev_new(TYPE_SD_CARD);
+        qdev_prop_set_drive_err(carddev, "drive", blk, &error_fatal);
+        qdev_realize_and_unref(carddev, bus, &error_fatal);
+    }
+
     if (!qtest_enabled()) {
         arm_load_kernel(&s->cpu[0], machine, &boot_info);
     }
diff --git a/include/hw/arm/fsl-imx8mm.h b/include/hw/arm/fsl-imx8mm.h
index 8a172b89e0..93a30a2f55 100644
--- a/include/hw/arm/fsl-imx8mm.h
+++ b/include/hw/arm/fsl-imx8mm.h
@@ -16,6 +16,7 @@
 #include "hw/misc/imx7_snvs.h"
 #include "hw/misc/imx8mp_analog.h"
 #include "hw/misc/imx8mp_ccm.h"
+#include "hw/sd/sdhci.h"
 #include "qom/object.h"
 #include "qemu/units.h"
 
@@ -29,6 +30,7 @@ enum FslImx8mmConfiguration {
     FSL_IMX8MM_NUM_CPUS         = 4,
     FSL_IMX8MM_NUM_IRQS         = 128,
     FSL_IMX8MM_NUM_UARTS        = 4,
+    FSL_IMX8MM_NUM_USDHCS       = 3,
 };
 
 struct FslImx8mmState {
@@ -41,6 +43,7 @@ struct FslImx8mmState {
     IMX7SNVSState      snvs;
     IMXSerialState     uart[FSL_IMX8MM_NUM_UARTS];
     MemoryRegion ocram;
+    SDHCIState         usdhc[FSL_IMX8MM_NUM_USDHCS];
 };
 
 enum FslImx8mmMemoryRegions {
@@ -155,6 +158,10 @@ enum FslImx8mmMemoryRegions {
 };
 
 enum FslImx8mmIrqs {
+    FSL_IMX8MM_USDHC1_IRQ   = 22,
+    FSL_IMX8MM_USDHC2_IRQ   = 23,
+    FSL_IMX8MM_USDHC3_IRQ   = 24,
+
     FSL_IMX8MM_UART1_IRQ    = 26,
     FSL_IMX8MM_UART2_IRQ    = 27,
     FSL_IMX8MM_UART3_IRQ    = 28,
-- 
2.43.0