[PATCH 02/10] sdhci: aspeed: Add SDR50 support

[Chin-Ting Kuo]

>From the analog waveform analysis result, SD/SDIO controller
of AST2600 cannot always work well with 200MHz. The upper bound
stable frequency for SD/SDIO controller is 100MHz. Thus, SDR50
supported bit, instead of SDR104, in capability 2 register
should be set in advance.

Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
---
 drivers/mmc/host/sdhci-of-aspeed.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c
index 6e4e132903a6..c6eaeb02e3f9 100644
--- a/drivers/mmc/host/sdhci-of-aspeed.c
+++ b/drivers/mmc/host/sdhci-of-aspeed.c
@@ -35,6 +35,8 @@
 #define ASPEED_SDC_CAP1_1_8V           (0 * 32 + 26)
 /* SDIO{14,24} */
 #define ASPEED_SDC_CAP2_SDR104         (1 * 32 + 1)
+/* SDIO{14,24} */
+#define ASPEED_SDC_CAP2_SDR50          (1 * 32 + 0)
 
 struct aspeed_sdc {
 	struct clk *clk;
@@ -410,11 +412,17 @@ static int aspeed_sdhci_probe(struct platform_device *pdev)
 	sdhci_get_of_property(pdev);
 
 	if (of_property_read_bool(np, "mmc-hs200-1_8v") ||
+		of_property_read_bool(np, "sd-uhs-sdr50") ||
 	    of_property_read_bool(np, "sd-uhs-sdr104")) {
 		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP1_1_8V,
 					       true, slot);
 	}
 
+	if (of_property_read_bool(np, "sd-uhs-sdr50")) {
+		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP2_SDR50,
+					       true, slot);
+	}
+
 	if (of_property_read_bool(np, "sd-uhs-sdr104")) {
 		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP2_SDR104,
 					       true, slot);
-- 
2.17.1