hw/arm/exynos4210: add a comment about a very similar SDHCI (Spec. v2)

Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: NAlistair Francis <alistair.francis@xilinx.com>
Message-Id: <20180208164818.7961-16-f4bug@amsat.org>

hw/arm/exynos4210.c

@@ -377,6 +377,18 @@ Exynos4210State *exynos4210_init(MemoryRegion *system_mem)
         BlockBackend *blk;
         DriveInfo *di;
 
+        /* Compatible with:
+         * - SD Host Controller Specification Version 2.0
+         * - SDIO Specification Version 2.0
+         * - MMC Specification Version 4.3
+         * - SDMA
+         * - ADMA2
+         *
+         * As this part of the Exynos4210 is not publically available,
+         * we used the "HS-MMC Controller S3C2416X RISC Microprocessor"
+         * public datasheet which is very similar (implementing
+         * MMC Specification Version 4.0 being the only difference noted)
+         */
         dev = qdev_create(NULL, TYPE_SYSBUS_SDHCI);
         qdev_prop_set_uint64(dev, "capareg", EXYNOS4210_SDHCI_CAPABILITIES);
         qdev_init_nofail(dev);