aspeed/sdhci: Fix reset sequence

BIT(0) of the ASPEED_SDHCI_INFO register is set by SW and polled until
the bit is cleared by HW.

Use the number of supported slots to define the default value of this
register (The AST2600 eMMC Controller only has one). Fix the reset
sequence by clearing automatically the RESET bit.

Cc: Eddie James <eajames@linux.ibm.com>
Fixes: 2bea128c3d0b ("hw/sd/aspeed_sdhci: New device")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20200819100956.2216690-9-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/sd/aspeed_sdhci.c

@@ -16,7 +16,9 @@
 #include "hw/qdev-properties.h"
 
 #define ASPEED_SDHCI_INFO            0x00
-#define  ASPEED_SDHCI_INFO_RESET     0x00030000
+#define  ASPEED_SDHCI_INFO_SLOT1     (1 << 17)
+#define  ASPEED_SDHCI_INFO_SLOT0     (1 << 16)
+#define  ASPEED_SDHCI_INFO_RESET     (1 << 0)
 #define ASPEED_SDHCI_DEBOUNCE        0x04
 #define  ASPEED_SDHCI_DEBOUNCE_RESET 0x00000005
 #define ASPEED_SDHCI_BUS             0x08
@@ -67,6 +69,10 @@ static void aspeed_sdhci_write(void *opaque, hwaddr addr, uint64_t val,
     AspeedSDHCIState *sdhci = opaque;
 
     switch (addr) {
+    case ASPEED_SDHCI_INFO:
+        /* The RESET bit automatically clears. */
+        sdhci->regs[TO_REG(addr)] = (uint32_t)val & ~ASPEED_SDHCI_INFO_RESET;
+        break;
     case ASPEED_SDHCI_SDIO_140:
         sdhci->slots[0].capareg = (uint64_t)(uint32_t)val;
         break;
@@ -155,7 +161,11 @@ static void aspeed_sdhci_reset(DeviceState *dev)
     AspeedSDHCIState *sdhci = ASPEED_SDHCI(dev);
 
     memset(sdhci->regs, 0, ASPEED_SDHCI_REG_SIZE);
-    sdhci->regs[TO_REG(ASPEED_SDHCI_INFO)] = ASPEED_SDHCI_INFO_RESET;
+
+    sdhci->regs[TO_REG(ASPEED_SDHCI_INFO)] = ASPEED_SDHCI_INFO_SLOT0;
+    if (sdhci->num_slots == 2) {
+        sdhci->regs[TO_REG(ASPEED_SDHCI_INFO)] |= ASPEED_SDHCI_INFO_SLOT1;
+    }
     sdhci->regs[TO_REG(ASPEED_SDHCI_DEBOUNCE)] = ASPEED_SDHCI_DEBOUNCE_RESET;
 }