mmc: sunxi: Add EMMC (MMC2) controller compatible

The MMC2 controller on the A64 is kind of a special beast.

While the general controller design is the same than the other MMC
controllers in the SoC, it also has a bunch of features and changes that
prevent it to be driven in the same way.

It has for example a different bus width limit, a different maximum
frequency, and, for some reason, the maximum buffer size of a DMA
descriptor.

Add a new compatible specifically for this controller.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Florian Vaussard <florian.vaussard@heig-vd.ch>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sunxi-mmc.c

@@ -5,6 +5,7 @@
  * (C) Copyright 2013-2014 O2S GmbH <www.o2s.ch>
  * (C) Copyright 2013-2014 David Lanzend�rfer <david.lanzendoerfer@o2s.ch>
  * (C) Copyright 2013-2014 Hans de Goede <hdegoede@redhat.com>
+ * (C) Copyright 2017 Sootech SA
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -1096,12 +1097,19 @@ static const struct sunxi_mmc_cfg sun50i_a64_cfg = {
 	.needs_new_timings = true,
 };
 
+static const struct sunxi_mmc_cfg sun50i_a64_emmc_cfg = {
+	.idma_des_size_bits = 13,
+	.clk_delays = NULL,
+	.can_calibrate = true,
+};
+
 static const struct of_device_id sunxi_mmc_of_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-mmc", .data = &sun4i_a10_cfg },
 	{ .compatible = "allwinner,sun5i-a13-mmc", .data = &sun5i_a13_cfg },
 	{ .compatible = "allwinner,sun7i-a20-mmc", .data = &sun7i_a20_cfg },
 	{ .compatible = "allwinner,sun9i-a80-mmc", .data = &sun9i_a80_cfg },
 	{ .compatible = "allwinner,sun50i-a64-mmc", .data = &sun50i_a64_cfg },
+	{ .compatible = "allwinner,sun50i-a64-emmc", .data = &sun50i_a64_emmc_cfg },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, sunxi_mmc_of_match);