[PATCH 08/21] hw/arm/fsl-imx8mp: Add USDHC storage controllers

[Bernhard Beschow <shentey@gmail.com>]

The USDHC emulation allows for running real-world images such as those generated
by Buildroot. Convert the board documentation accordingly instead of running a
Linux kernel with ephemeral storage.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
---
 docs/system/arm/imx8mp-evk.rst | 39 +++++++++++++++++++++++-----------
 include/hw/arm/fsl-imx8mp.h    |  7 ++++++
 hw/arm/fsl-imx8mp.c            | 28 ++++++++++++++++++++++++
 hw/arm/imx8mp-evk.c            | 18 ++++++++++++++++
 hw/arm/Kconfig                 |  1 +
 5 files changed, 81 insertions(+), 12 deletions(-)

diff --git a/docs/system/arm/imx8mp-evk.rst b/docs/system/arm/imx8mp-evk.rst
index d7d08cc198..1514bc5864 100644
--- a/docs/system/arm/imx8mp-evk.rst
+++ b/docs/system/arm/imx8mp-evk.rst
@@ -13,6 +13,7 @@ The ``imx8mp-evk`` machine implements the following devices:
  * Up to 4 Cortex-A53 Cores
  * Generic Interrupt Controller (GICv3)
  * 4 UARTs
+ * 3 USDHC Storage Controllers
  * Secure Non-Volatile Storage (SNVS) including an RTC
  * Clock Tree
 
@@ -25,25 +26,39 @@ for loading a Linux kernel.
 Direct Linux Kernel Boot
 ''''''''''''''''''''''''
 
-Linux mainline v6.12 release is tested at the time of writing. To build a Linux
-mainline kernel that can be booted by the ``imx8mp-evk`` machine, simply
-configure the kernel using the defconfig configuration:
+Probably the easiest way to get started with a whole Linux system on the machine
+is to generate an image with Buildroot. Version 2024.11.1 is tested at the time
+of writing and involves three steps. First run the following command in the
+toplevel directory of the Buildroot source tree:
 
 .. code-block:: bash
 
-  $ export ARCH=arm64
-  $ export CROSS_COMPILE=aarch64-linux-gnu-
-  $ make defconfig
+  $ make freescale_imx8mpevk_defconfig
   $ make
 
-To boot the newly built Linux kernel in QEMU with the ``imx8mp-evk`` machine,
-run:
+Once finished successfully there is an ``output/image`` subfolder. Navigate into
+it and resize the SD card image to a power of two:
+
+.. code-block:: bash
+
+  $ qemu-img resize sdcard.img 256M
+
+Finally, the device tree needs to be patched with the following commands which
+will remove the ``cpu-idle-states`` properties from CPU nodes:
+
+.. code-block:: bash
+
+  $ dtc imx8mp-evk.dtb | sed '/cpu-idle-states/d' > imx8mp-evk-patched.dts
+  $ dtc imx8mp-evk-patched.dts -o imx8mp-evk-patched.dtb
+
+Now that everything is prepared the newly built image can be run in the QEMU
+``imx8mp-evk`` machine:
 
 .. code-block:: bash
 
   $ qemu-system-aarch64 -M imx8mp-evk -smp 4 -m 3G \
       -display none -serial null -serial stdio \
-      -kernel arch/arm64/boot/Image \
-      -dtb arch/arm64/boot/dts/freescale/imx8mp-evk.dtb \
-      -initrd /path/to/rootfs.ext4 \
-      -append "root=/dev/ram"
+      -kernel Image \
+      -dtb imx8mp-evk-patched.dtb \
+      -append "root=/dev/mmcblk2p2" \
+      -drive file=sdcard.img,if=sd,bus=2,format=raw,id=mmcblk2
diff --git a/include/hw/arm/fsl-imx8mp.h b/include/hw/arm/fsl-imx8mp.h
index 9d2a757c2a..9832c05e8c 100644
--- a/include/hw/arm/fsl-imx8mp.h
+++ b/include/hw/arm/fsl-imx8mp.h
@@ -14,6 +14,7 @@
 #include "hw/intc/arm_gicv3_common.h"
 #include "hw/misc/imx7_snvs.h"
 #include "hw/misc/imx8mp_ccm.h"
+#include "hw/sd/sdhci.h"
 #include "qom/object.h"
 #include "qemu/units.h"
 
@@ -27,6 +28,7 @@ enum FslImx8mpConfiguration {
     FSL_IMX8MP_NUM_CPUS         = 4,
     FSL_IMX8MP_NUM_IRQS         = 160,
     FSL_IMX8MP_NUM_UARTS        = 4,
+    FSL_IMX8MP_NUM_USDHCS       = 3,
 };
 
 struct FslImx8mpState {
@@ -38,6 +40,7 @@ struct FslImx8mpState {
     IMX8MPAnalogState  analog;
     IMX7SNVSState      snvs;
     IMXSerialState     uart[FSL_IMX8MP_NUM_UARTS];
+    SDHCIState         usdhc[FSL_IMX8MP_NUM_USDHCS];
 };
 
 enum FslImx8mpMemoryRegions {
@@ -183,6 +186,10 @@ enum FslImx8mpMemoryRegions {
 };
 
 enum FslImx8mpIrqs {
+    FSL_IMX8MP_USDHC1_IRQ   = 22,
+    FSL_IMX8MP_USDHC2_IRQ   = 23,
+    FSL_IMX8MP_USDHC3_IRQ   = 24,
+
     FSL_IMX8MP_UART1_IRQ    = 26,
     FSL_IMX8MP_UART2_IRQ    = 27,
     FSL_IMX8MP_UART3_IRQ    = 28,
diff --git a/hw/arm/fsl-imx8mp.c b/hw/arm/fsl-imx8mp.c
index 0abde2b1fc..612ea7bf93 100644
--- a/hw/arm/fsl-imx8mp.c
+++ b/hw/arm/fsl-imx8mp.c
@@ -210,6 +210,11 @@ static void fsl_imx8mp_init(Object *obj)
         snprintf(name, NAME_SIZE, "uart%d", i + 1);
         object_initialize_child(obj, name, &s->uart[i], TYPE_IMX_SERIAL);
     }
+
+    for (i = 0; i < FSL_IMX8MP_NUM_USDHCS; i++) {
+        snprintf(name, NAME_SIZE, "usdhc%d", i + 1);
+        object_initialize_child(obj, name, &s->usdhc[i], TYPE_IMX_USDHC);
+    }
 }
 
 static void fsl_imx8mp_realize(DeviceState *dev, Error **errp)
@@ -350,6 +355,28 @@ static void fsl_imx8mp_realize(DeviceState *dev, Error **errp)
                            qdev_get_gpio_in(gicdev, serial_table[i].irq));
     }
 
+    /* USDHCs */
+    for (i = 0; i < FSL_IMX8MP_NUM_USDHCS; i++) {
+        static const struct {
+            hwaddr addr;
+            unsigned int irq;
+        } usdhc_table[FSL_IMX8MP_NUM_USDHCS] = {
+            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC1].addr, FSL_IMX8MP_USDHC1_IRQ },
+            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC2].addr, FSL_IMX8MP_USDHC2_IRQ },
+            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC3].addr, FSL_IMX8MP_USDHC3_IRQ },
+        };
+
+        object_property_set_uint(OBJECT(&s->usdhc[i]), "vendor",
+                                 SDHCI_VENDOR_IMX, &error_abort);
+        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;
@@ -367,6 +394,7 @@ static void fsl_imx8mp_realize(DeviceState *dev, Error **errp)
         case FSL_IMX8MP_RAM:
         case FSL_IMX8MP_SNVS_HP:
         case FSL_IMX8MP_UART1 ... FSL_IMX8MP_UART4:
+        case FSL_IMX8MP_USDHC1 ... FSL_IMX8MP_USDHC3:
             /* device implemented and treated above */
             break;
 
diff --git a/hw/arm/imx8mp-evk.c b/hw/arm/imx8mp-evk.c
index 2756d4c21c..27d9e9e8ee 100644
--- a/hw/arm/imx8mp-evk.c
+++ b/hw/arm/imx8mp-evk.c
@@ -11,6 +11,7 @@
 #include "hw/arm/boot.h"
 #include "hw/arm/fsl-imx8mp.h"
 #include "hw/boards.h"
+#include "hw/qdev-properties.h"
 #include "system/qtest.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
@@ -40,6 +41,23 @@ static void imx8mp_evk_init(MachineState *machine)
     memory_region_add_subregion(get_system_memory(), FSL_IMX8MP_RAM_START,
                                 machine->ram);
 
+    for (int i = 0; i < FSL_IMX8MP_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/hw/arm/Kconfig b/hw/arm/Kconfig
index adb4ed8076..f880c03d35 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -582,6 +582,7 @@ config FSL_IMX8MP
     imply TEST_DEVICES
     select ARM_GIC
     select IMX
+    select SDHCI
     select UNIMP
 
 config FSL_IMX8MP_EVK
-- 
2.48.1