mmc: mtk-sd: add support for config found in mt7620 family SOCs.

mt7620 family MIPS SOCs contain the mtk-sd silicon.
Add support for this.
Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Chaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/mtk-sd.txt

@@ -16,6 +16,7 @@ Required properties:
 	"mediatek,mt2712-mmc": for mmc host ip compatible with mt2712
 	"mediatek,mt7622-mmc": for MT7622 SoC
 	"mediatek,mt7623-mmc", "mediatek,mt2701-mmc": for MT7623 SoC
+	"mediatek,mt7620-mmc", for MT7621 SoC (and others)
 
 - reg: physical base address of the controller and length
 - interrupts: Should contain MSDC interrupt number

drivers/mmc/host/mtk-sd.c

@@ -517,6 +517,17 @@ static const struct mtk_mmc_compatible mt8516_compat = {
 	.stop_clk_fix = true,
 };
 
+static const struct mtk_mmc_compatible mt7620_compat = {
+	.clk_div_bits = 8,
+	.hs400_tune = false,
+	.pad_tune_reg = MSDC_PAD_TUNE,
+	.async_fifo = false,
+	.data_tune = false,
+	.busy_check = false,
+	.stop_clk_fix = false,
+	.enhance_rx = false,
+};
+
 static const struct of_device_id msdc_of_ids[] = {
 	{ .compatible = "mediatek,mt8135-mmc", .data = &mt8135_compat},
 	{ .compatible = "mediatek,mt8173-mmc", .data = &mt8173_compat},
@@ -525,6 +536,7 @@ static const struct of_device_id msdc_of_ids[] = {
 	{ .compatible = "mediatek,mt2712-mmc", .data = &mt2712_compat},
 	{ .compatible = "mediatek,mt7622-mmc", .data = &mt7622_compat},
 	{ .compatible = "mediatek,mt8516-mmc", .data = &mt8516_compat},
+	{ .compatible = "mediatek,mt7620-mmc", .data = &mt7620_compat},
 	{}
 };
 MODULE_DEVICE_TABLE(of, msdc_of_ids);