mmc: sdhci-of-aspeed: Configure the SDHCIs as specified by the devicetree.

The hardware provides capability configuration registers for each SDHCI
in the global configuration space for the SD controller. Writes to the
global capability registers are mirrored to the capability registers in
the associated SDHCI. Configuration of the capabilities must be written
through the mirror registers prior to initialisation of the SDHCI.

Signed-off-by: Steven Lee <[e-mail]>
Reviewed-by: Andrew Jeffery <[e-mail]>
Reviewed-by: Joel Stanley <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/sdhci-of-aspeed.c

···
 #define   ASPEED_SDC_S0_PHASE_OUT_EN	GENMASK(1, 0)
 #define   ASPEED_SDC_PHASE_MAX		31
 
+/* SDIO{10,20} */
+#define ASPEED_SDC_CAP1_1_8V           (0 * 32 + 26)
+/* SDIO{14,24} */
+#define ASPEED_SDC_CAP2_SDR104         (1 * 32 + 1)
+
 struct aspeed_sdc {
 	struct clk *clk;
 	struct resource *res;
···
 	struct mmc_clk_phase_map phase_map;
 	const struct aspeed_sdhci_phase_desc *phase_desc;
 };
+
+/*
+ * The function sets the mirror register for updating
+ * capbilities of the current slot.
+ *
+ *   slot | capability  | caps_reg | mirror_reg
+ *   -----|-------------|----------|------------
+ *     0  | CAP1_1_8V   | SDIO140  |   SDIO10
+ *     0  | CAP2_SDR104 | SDIO144  |   SDIO14
+ *     1  | CAP1_1_8V   | SDIO240  |   SDIO20
+ *     1  | CAP2_SDR104 | SDIO244  |   SDIO24
+ */
+static void aspeed_sdc_set_slot_capability(struct sdhci_host *host, struct aspeed_sdc *sdc,
+					   int capability, bool enable, u8 slot)
+{
+	u32 mirror_reg_offset;
+	u32 cap_val;
+	u8 cap_reg;
+
+	if (slot > 1)
+		return;
+
+	cap_reg = capability / 32;
+	cap_val = sdhci_readl(host, 0x40 + (cap_reg * 4));
+	if (enable)
+		cap_val |= BIT(capability % 32);
+	else
+		cap_val &= ~BIT(capability % 32);
+	mirror_reg_offset = ((slot + 1) * 0x10) + (cap_reg * 4);
+	writel(cap_val, sdc->regs + mirror_reg_offset);
+}
 
 static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc,
 					   struct aspeed_sdhci *sdhci,
···
 static int aspeed_sdhci_probe(struct platform_device *pdev)
 {
 	const struct aspeed_sdhci_pdata *aspeed_pdata;
+	struct device_node *np = pdev->dev.of_node;
 	struct sdhci_pltfm_host *pltfm_host;
 	struct aspeed_sdhci *dev;
 	struct sdhci_host *host;
···
 	dev_info(&pdev->dev, "Configured for slot %d\n", slot);
 
 	sdhci_get_of_property(pdev);
+
+	if (of_property_read_bool(np, "mmc-hs200-1_8v") ||
+	    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-sdr104")) {
+		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP2_SDR104,
+					       true, slot);
+	}
 
 	pltfm_host->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pltfm_host->clk))