m25p80: Introduce COLLECTING_VAR_LEN_DATA state.

Some flash allows to stop read at any time.
Allow framework to support this.

Signed-off-by: Marcin Krzeminski <marcin.krzeminski@nokia.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1466755631-25201-5-git-send-email-marcin.krzeminski@nokia.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/block/m25p80.c

@@ -330,6 +330,7 @@ typedef enum {
     STATE_PAGE_PROGRAM,
     STATE_READ,
     STATE_COLLECTING_DATA,
+    STATE_COLLECTING_VAR_LEN_DATA,
     STATE_READING_DATA,
 } CMDState;
 
@@ -872,6 +873,9 @@ static int m25p80_cs(SSISlave *ss, bool select)
     Flash *s = M25P80(ss);
 
     if (select) {
+        if (s->state == STATE_COLLECTING_VAR_LEN_DATA) {
+            complete_collecting_data(s);
+        }
         s->len = 0;
         s->pos = 0;
         s->state = STATE_IDLE;
@@ -905,6 +909,7 @@ static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t tx)
         break;
 
     case STATE_COLLECTING_DATA:
+    case STATE_COLLECTING_VAR_LEN_DATA:
         s->data[s->len] = (uint8_t)tx;
         s->len++;