[PATCH 14/22] hw/sd: ssi-sd: Support single block write

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

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

Add 2 more states for the block write operation. The SPI host needs
to send a data start tocken to start the transfer, and the data block
written to the card will be acknowledged by a data response tocken.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
---

 hw/sd/ssi-sd.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index 8eb48550cf..21a96e91f0 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -42,6 +42,8 @@ typedef enum {
     SSI_SD_DATA_START,
     SSI_SD_DATA_READ,
     SSI_SD_DATA_CRC16,
+    SSI_SD_DATA_WRITE,
+    SSI_SD_SKIP_CRC16,
 } ssi_sd_mode;
 
 struct ssi_sd_state {
@@ -52,6 +54,7 @@ struct ssi_sd_state {
     uint8_t response[5];
     uint16_t crc16;
     int32_t read_bytes;
+    int32_t write_bytes;
     int32_t arglen;
     int32_t response_pos;
     int32_t stopping;
@@ -90,6 +93,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(ssi_sd_state, SSI_SD)
 /* dummy value - don't care */
 #define SSI_DUMMY               0xff
 
+/* data accepted */
+#define DATA_RESPONSE_ACCEPTED  0x05
+
 static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
 {
     ssi_sd_state *s = SSI_SD(dev);
@@ -103,10 +109,17 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
 
     switch (s->mode) {
     case SSI_SD_CMD:
-        if (val == SSI_DUMMY) {
+        switch (val) {
+        case SSI_DUMMY:
             DPRINTF("NULL command\n");
             return SSI_DUMMY;
+            break;
+        case SSI_TOKEN_SINGLE:
+            DPRINTF("Start write block\n");
+            s->mode = SSI_SD_DATA_WRITE;
+            return SSI_DUMMY;
         }
+
         s->cmd = val & 0x3f;
         s->mode = SSI_SD_CMDARG;
         s->arglen = 0;
@@ -235,6 +248,27 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
             s->response_pos = 0;
         }
         return val;
+    case SSI_SD_DATA_WRITE:
+        sdbus_write_byte(&s->sdbus, val);
+        s->write_bytes++;
+        if (!sdbus_receive_ready(&s->sdbus) || s->write_bytes == 512) {
+            DPRINTF("Data write end\n");
+            s->mode = SSI_SD_SKIP_CRC16;
+            s->response_pos = 0;
+        }
+        return val;
+    case SSI_SD_SKIP_CRC16:
+        /* we don't verify the crc16 */
+        s->response_pos++;
+        if (s->response_pos == 2) {
+            DPRINTF("CRC16 receive end\n");
+            s->mode = SSI_SD_RESPONSE;
+            s->write_bytes = 0;
+            s->arglen = 1;
+            s->response[0] = DATA_RESPONSE_ACCEPTED;
+            s->response_pos = 0;
+        }
+        return SSI_DUMMY;
     }
     /* Should never happen.  */
     return SSI_DUMMY;
@@ -325,6 +359,7 @@ static void ssi_sd_reset(DeviceState *dev)
     memset(s->response, 0, sizeof(s->response));
     s->crc16 = 0;
     s->read_bytes = 0;
+    s->write_bytes = 0;
     s->arglen = 0;
     s->response_pos = 0;
     s->stopping = 0;
-- 
2.25.1