hw/sd/sdhci: Support big endian SD host controller interfaces

Some SDHCI IP can be synthetized in various endianness:
https://github.com/u-boot/u-boot/blob/v2021.04/doc/README.fsl-esdhc

 - CONFIG_SYS_FSL_ESDHC_BE

   ESDHC IP is in big-endian mode. Accessing ESDHC registers can be
   determined by ESDHC IP's endian mode or processor's endian mode.

Our current implementation is little-endian. In order to support
big endianness:

- Rename current MemoryRegionOps as sdhci_mmio_le_ops ('le')
- Add an 'endianness' property to SDHCIState (default little endian)
- Set the 'io_ops' field in realize() after checking the property
- Add the sdhci_mmio_be_ops (big-endian) MemoryRegionOps.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20221101222934.52444-3-philmd@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

hw/sd/sdhci-internal.h

@@ -308,6 +308,7 @@ extern const VMStateDescription sdhci_vmstate;
 #define SDHC_CAPAB_REG_DEFAULT 0x057834b4
 
 #define DEFINE_SDHCI_COMMON_PROPERTIES(_state) \
+    DEFINE_PROP_UINT8("endianness", _state, endianness, DEVICE_LITTLE_ENDIAN), \
     DEFINE_PROP_UINT8("sd-spec-version", _state, sd_spec_version, 2), \
     DEFINE_PROP_UINT8("uhs", _state, uhs_mode, UHS_NOT_SUPPORTED), \
     DEFINE_PROP_UINT8("vendor", _state, vendor, SDHCI_VENDOR_NONE), \

hw/sd/sdhci.c

@@ -1329,7 +1329,7 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
                        value >> shift, value >> shift);
 }
 
-static const MemoryRegionOps sdhci_mmio_ops = {
+static const MemoryRegionOps sdhci_mmio_le_ops = {
     .read = sdhci_read,
     .write = sdhci_write,
     .valid = {
@@ -1340,6 +1340,21 @@ static const MemoryRegionOps sdhci_mmio_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+static const MemoryRegionOps sdhci_mmio_be_ops = {
+    .read = sdhci_read,
+    .write = sdhci_write,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+        .unaligned = false
+    },
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
 static void sdhci_init_readonly_registers(SDHCIState *s, Error **errp)
 {
     ERRP_GUARD();
@@ -1367,8 +1382,6 @@ void sdhci_initfn(SDHCIState *s)
 
     s->insert_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_raise_insertion_irq, s);
     s->transfer_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_data_transfer, s);
-
-    s->io_ops = &sdhci_mmio_ops;
 }
 
 void sdhci_uninitfn(SDHCIState *s)
@@ -1384,10 +1397,23 @@ void sdhci_common_realize(SDHCIState *s, Error **errp)
 {
     ERRP_GUARD();
 
+    switch (s->endianness) {
+    case DEVICE_LITTLE_ENDIAN:
+        s->io_ops = &sdhci_mmio_le_ops;
+        break;
+    case DEVICE_BIG_ENDIAN:
+        s->io_ops = &sdhci_mmio_be_ops;
+        break;
+    default:
+        error_setg(errp, "Incorrect endianness");
+        return;
+    }
+
     sdhci_init_readonly_registers(s, errp);
     if (*errp) {
         return;
     }
+
     s->buf_maxsz = sdhci_get_fifolen(s);
     s->fifo_buffer = g_malloc0(s->buf_maxsz);
 

include/hw/sd/sdhci.h

@@ -96,6 +96,7 @@ struct SDHCIState {
     /* Configurable properties */
     bool pending_insert_quirk; /* Quirk for Raspberry Pi card insert int */
     uint32_t quirks;
+    uint8_t endianness;
     uint8_t sd_spec_version;
     uint8_t uhs_mode;
     uint8_t vendor;        /* For vendor specific functionality */