[PATCH v4 6/9] hw/sd: ssi-sd: Support multiple block write

[Bin Meng <bmeng.cn@gmail.com>]

From: Bin Meng <bin.meng@windriver.com>

For a multiple block write operation, each block begins with a multi
write start token. Unlike the SD mode that the multiple block write
ends when receiving a STOP_TRAN command (CMD12), a special stop tran
token is used to signal the card.

Emulating this by manually sending a CMD12 to the SD card core, to
bring it out of the receiving data state.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

---

Changes in v4:
- Keep the card state to SSI_SD_CMD instead of SSI_SD_RESPONSE after
  receiving the STOP_TRAN token per the spec

 hw/sd/ssi-sd.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index 1205ad8b52..200e885225 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -4,6 +4,11 @@
  * Copyright (c) 2007-2009 CodeSourcery.
  * Written by Paul Brook
  *
+ * Copyright (c) 2021 Wind River Systems, Inc.
+ * Improved by Bin Meng <bin.meng@windriver.com>
+ *
+ * Validated with U-Boot v2021.01 and Linux v5.10 mmc_spi driver
+ *
  * This code is licensed under the GNU GPL v2.
  *
  * Contributions after 2012-01-13 are licensed under the terms of the
@@ -82,6 +87,10 @@ OBJECT_DECLARE_SIMPLE_TYPE(ssi_sd_state, SSI_SD)
 #define SSI_SDR_ADDRESS_ERROR   0x2000
 #define SSI_SDR_PARAMETER_ERROR 0x4000
 
+/* multiple block write */
+#define SSI_TOKEN_MULTI_WRITE   0xfc
+/* terminate multiple block write */
+#define SSI_TOKEN_STOP_TRAN     0xfd
 /* single block read/write, multiple block read */
 #define SSI_TOKEN_SINGLE        0xfe
 
@@ -94,6 +103,8 @@ OBJECT_DECLARE_SIMPLE_TYPE(ssi_sd_state, SSI_SD)
 static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
 {
     ssi_sd_state *s = SSI_SD(dev);
+    SDRequest request;
+    uint8_t longresp[16];
 
     /*
      * Special case: allow CMD12 (STOP TRANSMISSION) while reading data.
@@ -125,8 +136,28 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
             return SSI_DUMMY;
             break;
         case SSI_TOKEN_SINGLE:
+        case SSI_TOKEN_MULTI_WRITE:
             DPRINTF("Start write block\n");
             s->mode = SSI_SD_DATA_WRITE;
+            return SSI_DUMMY;
+        case SSI_TOKEN_STOP_TRAN:
+            DPRINTF("Stop multiple write\n");
+
+            /* manually issue cmd12 to stop the transfer */
+            request.cmd = 12;
+            request.arg = 0;
+            s->arglen = sdbus_do_command(&s->sdbus, &request, longresp);
+            if (s->arglen <= 0) {
+                s->arglen = 1;
+                /* a zero value indicates the card is busy */
+                s->response[0] = 0;
+                DPRINTF("SD card busy\n");
+            } else {
+                s->arglen = 1;
+                /* a non-zero value indicates the card is ready */
+                s->response[0] = SSI_DUMMY;
+            }
+
             return SSI_DUMMY;
         }
 
@@ -136,8 +167,6 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
         return SSI_DUMMY;
     case SSI_SD_CMDARG:
         if (s->arglen == 4) {
-            SDRequest request;
-            uint8_t longresp[16];
             /* FIXME: Check CRC.  */
             request.cmd = s->cmd;
             request.arg = ldl_be_p(s->cmdarg);
-- 
2.25.1