[RFC PATCH 14/17] hw/sd: Add CMD21 tuning sequence

["Cédric Le Goater" <clg@kaod.org>]

From: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>

MMC cards support different tuning sequence for entering HS200 mode.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
[ clg: - ported on aspeed-7.0 patchset ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 hw/sd/sd.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 289764a38bf3..3a3b9d62e1ba 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -2071,6 +2071,30 @@ static const uint8_t sd_tuning_block_pattern[SD_TUNING_BLOCK_SIZE] = {
     0xbb, 0xff, 0xf7, 0xff,         0xf7, 0x7f, 0x7b, 0xde,
 };
 
+#define EXCSD_BUS_WIDTH_OFFSET 183
+#define BUS_WIDTH_8_MASK    0x4
+#define BUS_WIDTH_4_MASK    0x2
+#define MMC_TUNING_BLOCK_SIZE   128
+
+static const uint8_t mmc_tuning_block_pattern[128] = {
+       0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
+       0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc,
+       0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff,
+       0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff,
+       0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd,
+       0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb,
+       0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff,
+       0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff,
+       0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
+       0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc,
+       0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff,
+       0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee,
+       0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd,
+       0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff,
+       0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff,
+       0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
+};
+
 uint8_t sd_read_byte(SDState *sd)
 {
     /* TODO: Append CRCs */
@@ -2165,6 +2189,21 @@ uint8_t sd_read_byte(SDState *sd)
         ret = sd_tuning_block_pattern[sd->data_offset++];
         break;
 
+    case 21:    /* CMD21: SEND_TUNING_BLOCK (MMC) */
+        if (sd->data_offset >= MMC_TUNING_BLOCK_SIZE - 1) {
+            sd->state = sd_transfer_state;
+        }
+        if (sd->ext_csd[EXCSD_BUS_WIDTH_OFFSET] & BUS_WIDTH_8_MASK) {
+            ret = mmc_tuning_block_pattern[sd->data_offset++];
+        } else {
+            /* Return LSB Nibbles of two byte from the 8bit tuning block
+             * for 4bit mode
+             */
+            ret = mmc_tuning_block_pattern[sd->data_offset++] & 0x0F;
+            ret |= (mmc_tuning_block_pattern[sd->data_offset++] & 0x0F) << 4;
+        }
+        break;
+
     case 22:	/* ACMD22: SEND_NUM_WR_BLOCKS */
         ret = sd->data[sd->data_offset ++];
 
-- 
2.34.1