hw/sd: Add sdbus_read_data() to read multiples bytes on the data line

Add a sdbus_read_data() method to read multiple bytes on the
data line of a SD bus.
We might improve the tracing later, for now keep logging each
byte individually.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200814092346.21825-7-f4bug@amsat.org>

2 files changed, 24 insertions, 0 deletions

diff --git a/hw/sd/core.c b/hw/sd/core.c
index 9c2781ebf9..957d116f1a 100644
--- a/hw/sd/core.c
+++ b/hw/sd/core.c
@@ -144,6 +144,21 @@ uint8_t sdbus_read_byte(SDBus *sdbus)
     return value;
 }
 
+void sdbus_read_data(SDBus *sdbus, void *buf, size_t length)
+{
+    SDState *card = get_card(sdbus);
+    uint8_t *data = buf;
+
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        for (size_t i = 0; i < length; i++) {
+            data[i] = sc->read_byte(card);
+            trace_sdbus_read(sdbus_name(sdbus), data[i]);
+        }
+    }
+}
+
 bool sdbus_data_ready(SDBus *sdbus)
 {
     SDState *card = get_card(sdbus);
diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index 3ae3e8939b..ac02d61a7a 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -184,6 +184,15 @@ uint8_t sdbus_read_byte(SDBus *sd);
  * Write multiple bytes of data on the data lines of a SD bus.
  */
 void sdbus_write_data(SDBus *sdbus, const void *buf, size_t length);
+/**
+ * Read data from a SD bus.
+ * @sdbus: bus
+ * @buf: buffer to read data into
+ * @length: number of bytes to read
+ *
+ * Read multiple bytes of data on the data lines of a SD bus.
+ */
+void sdbus_read_data(SDBus *sdbus, void *buf, size_t length);
 bool sdbus_data_ready(SDBus *sd);
 bool sdbus_get_inserted(SDBus *sd);
 bool sdbus_get_readonly(SDBus *sd);