sdhci: implement the Host Control 2 register (tuning sequence)

[based on a patch from Alistair Francis <alistair.francis@xilinx.com>
 from qemu/xilinx tag xilinx-v2015.2]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-Id: <20180208164818.7961-20-f4bug@amsat.org>

2 files changed, 29 insertions, 3 deletions

diff --git a/hw/sd/sdhci-internal.h b/hw/sd/sdhci-internal.h
index 9ab1a71866..b3f2692702 100644
--- a/hw/sd/sdhci-internal.h
+++ b/hw/sd/sdhci-internal.h
@@ -188,6 +188,16 @@ FIELD(SDHC_ACMD12ERRSTS, TIMEOUT_ERR,  1, 1);
 FIELD(SDHC_ACMD12ERRSTS, CRC_ERR,      2, 1);
 FIELD(SDHC_ACMD12ERRSTS, INDEX_ERR,    4, 1);
 
+/* Host Control Register 2 (since v3) */
+#define SDHC_HOSTCTL2                  0x3E
+FIELD(SDHC_HOSTCTL2, UHS_MODE_SEL,     0, 3);
+FIELD(SDHC_HOSTCTL2, V18_ENA,          3, 1); /* UHS-I only */
+FIELD(SDHC_HOSTCTL2, DRIVER_STRENGTH,  4, 2); /* UHS-I only */
+FIELD(SDHC_HOSTCTL2, EXECUTE_TUNING,   6, 1); /* UHS-I only */
+FIELD(SDHC_HOSTCTL2, SAMPLING_CLKSEL,  7, 1); /* UHS-I only */
+FIELD(SDHC_HOSTCTL2, ASYNC_INT,       14, 1);
+FIELD(SDHC_HOSTCTL2, PRESET_ENA,      15, 1);
+
 /* HWInit Capabilities Register 0x05E80080 */
 #define SDHC_CAPAB                     0x40
 FIELD(SDHC_CAPAB, TOCLKFREQ,           0, 6);
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 55b3f3a7db..2712b8218a 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -408,14 +408,29 @@ static void sdhci_end_transfer(SDHCIState *s)
 static void sdhci_read_block_from_card(SDHCIState *s)
 {
     int index = 0;
+    uint8_t data;
+    const uint16_t blk_size = s->blksize & BLOCK_SIZE_MASK;
 
     if ((s->trnmod & SDHC_TRNS_MULTI) &&
             (s->trnmod & SDHC_TRNS_BLK_CNT_EN) && (s->blkcnt == 0)) {
         return;
     }
 
-    for (index = 0; index < (s->blksize & BLOCK_SIZE_MASK); index++) {
-        s->fifo_buffer[index] = sdbus_read_data(&s->sdbus);
+    for (index = 0; index < blk_size; index++) {
+        data = sdbus_read_data(&s->sdbus);
+        if (!FIELD_EX32(s->hostctl2, SDHC_HOSTCTL2, EXECUTE_TUNING)) {
+            /* Device is not in tunning */
+            s->fifo_buffer[index] = data;
+        }
+    }
+
+    if (FIELD_EX32(s->hostctl2, SDHC_HOSTCTL2, EXECUTE_TUNING)) {
+        /* Device is in tunning */
+        s->hostctl2 &= ~R_SDHC_HOSTCTL2_EXECUTE_TUNING_MASK;
+        s->hostctl2 |= R_SDHC_HOSTCTL2_SAMPLING_CLKSEL_MASK;
+        s->prnsts &= ~(SDHC_DAT_LINE_ACTIVE | SDHC_DOING_READ |
+                       SDHC_DATA_INHIBIT);
+        goto read_done;
     }
 
     /* New data now available for READ through Buffer Port Register */
@@ -440,6 +455,7 @@ static void sdhci_read_block_from_card(SDHCIState *s)
         }
     }
 
+read_done:
     sdhci_update_irq(s);
 }
 
@@ -1005,7 +1021,7 @@ static uint64_t sdhci_read(void *opaque, hwaddr offset, unsigned size)
         ret = s->norintsigen | (s->errintsigen << 16);
         break;
     case SDHC_ACMD12ERRSTS:
-        ret = s->acmd12errsts;
+        ret = s->acmd12errsts | (s->hostctl2 << 16);
         break;
     case SDHC_CAPAB:
         ret = (uint32_t)s->capareg;