hw/sd: Add QOM bus which SD cards plug in to

Add a QOM bus for SD cards to plug in to.

Note that since sd_enable() is used only by one board and there
only as part of a broken implementation, we do not provide it in
the SDBus API (but instead add a warning comment about the old
function). Whoever converts OMAP and the nseries boards to QOM
will need to either implement the card switch properly or move
the enable hack into the OMAP MMC controller model.

In the SDBus API, the old-style use of sd_set_cb to register some
qemu_irqs for notification of card insertion and write-protect
toggling is replaced with methods in the SDBusClass which the
card calls on status changes and methods in the SDClass which
the controller can call to find out the current status. The
query methods will allow us to remove the abuse of the 'register
irqs' API by controllers in their reset methods to trigger
the card to tell them about the current status again.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 1455646193-13238-5-git-send-email-peter.maydell@linaro.org

1 files changed, 62 insertions, 0 deletions

diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index 404d5896db..d5d273a449 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -67,10 +67,51 @@ typedef struct {
 } SDRequest;
 
 typedef struct SDState SDState;
+typedef struct SDBus SDBus;
 
 #define TYPE_SD_CARD "sd-card"
 #define SD_CARD(obj) OBJECT_CHECK(SDState, (obj), TYPE_SD_CARD)
+#define SD_CARD_CLASS(klass) \
+    OBJECT_CLASS_CHECK(SDCardClass, (klass), TYPE_SD_CARD)
+#define SD_CARD_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(SDCardClass, (obj), TYPE_SD_CARD)
 
+typedef struct {
+    /*< private >*/
+    DeviceClass parent_class;
+    /*< public >*/
+
+    int (*do_command)(SDState *sd, SDRequest *req, uint8_t *response);
+    void (*write_data)(SDState *sd, uint8_t value);
+    uint8_t (*read_data)(SDState *sd);
+    bool (*data_ready)(SDState *sd);
+    void (*enable)(SDState *sd, bool enable);
+    bool (*get_inserted)(SDState *sd);
+    bool (*get_readonly)(SDState *sd);
+} SDCardClass;
+
+#define TYPE_SD_BUS "sd-bus"
+#define SD_BUS(obj) OBJECT_CHECK(SDBus, (obj), TYPE_SD_BUS)
+#define SD_BUS_CLASS(klass) OBJECT_CLASS_CHECK(SDBusClass, (klass), TYPE_SD_BUS)
+#define SD_BUS_GET_CLASS(obj) OBJECT_GET_CLASS(SDBusClass, (obj), TYPE_SD_BUS)
+
+struct SDBus {
+    BusState qbus;
+};
+
+typedef struct {
+    /*< private >*/
+    BusClass parent_class;
+    /*< public >*/
+
+    /* These methods are called by the SD device to notify the controller
+     * when the card insertion or readonly status changes
+     */
+    void (*set_inserted)(DeviceState *dev, bool inserted);
+    void (*set_readonly)(DeviceState *dev, bool readonly);
+} SDBusClass;
+
+/* Legacy functions to be used only by non-qdevified callers */
 SDState *sd_init(BlockBackend *bs, bool is_spi);
 int sd_do_command(SDState *sd, SDRequest *req,
                   uint8_t *response);
@@ -78,6 +119,27 @@ void sd_write_data(SDState *sd, uint8_t value);
 uint8_t sd_read_data(SDState *sd);
 void sd_set_cb(SDState *sd, qemu_irq readonly, qemu_irq insert);
 bool sd_data_ready(SDState *sd);
+/* sd_enable should not be used -- it is only used on the nseries boards,
+ * where it is part of a broken implementation of the MMC card slot switch
+ * (there should be two card slots which are multiplexed to a single MMC
+ * controller, but instead we model it with one card and controller and
+ * disable the card when the second slot is selected, so it looks like the
+ * second slot is always empty).
+ */
 void sd_enable(SDState *sd, bool enable);
 
+/* Functions to be used by qdevified callers (working via
+ * an SDBus rather than directly with SDState)
+ */
+int sdbus_do_command(SDBus *sd, SDRequest *req, uint8_t *response);
+void sdbus_write_data(SDBus *sd, uint8_t value);
+uint8_t sdbus_read_data(SDBus *sd);
+bool sdbus_data_ready(SDBus *sd);
+bool sdbus_get_inserted(SDBus *sd);
+bool sdbus_get_readonly(SDBus *sd);
+
+/* Functions to be used by SD devices to report back to qdevified controllers */
+void sdbus_set_inserted(SDBus *sd, bool inserted);
+void sdbus_set_readonly(SDBus *sd, bool inserted);
+
 #endif	/* __hw_sd_h */