mmc: sdhci-acpi: Add support for ACPI HID of AMD Controller with HS400

This patch supports HS400 for AMD upcoming emmc 5.0 controller.The
HS400 and HS200 mode requires hardware work around also. This patch
adds the quirks for the same.
Signed-off-by: Nehal-bakulchandra Shah <Nehal-bakulchandra.Shah@amd.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-acpi.c

@@ -446,6 +446,83 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_qcom_sd = {
 	.caps    = MMC_CAP_NONREMOVABLE,
 };
 
+/* AMD sdhci reset dll register. */
+#define SDHCI_AMD_RESET_DLL_REGISTER    0x908
+
+static int amd_select_drive_strength(struct mmc_card *card,
+				     unsigned int max_dtr, int host_drv,
+				     int card_drv, int *drv_type)
+{
+	return MMC_SET_DRIVER_TYPE_A;
+}
+
+static void sdhci_acpi_amd_hs400_dll(struct sdhci_host *host)
+{
+	/* AMD Platform requires dll setting */
+	sdhci_writel(host, 0x40003210, SDHCI_AMD_RESET_DLL_REGISTER);
+	usleep_range(10, 20);
+	sdhci_writel(host, 0x40033210, SDHCI_AMD_RESET_DLL_REGISTER);
+}
+
+/*
+ * For AMD Platform it is required to disable the tuning
+ * bit first controller to bring to HS Mode from HS200
+ * mode, later enable to tune to HS400 mode.
+ */
+static void amd_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	unsigned int old_timing = host->timing;
+
+	sdhci_set_ios(mmc, ios);
+	if (old_timing == MMC_TIMING_MMC_HS200 &&
+	    ios->timing == MMC_TIMING_MMC_HS)
+		sdhci_writew(host, 0x9, SDHCI_HOST_CONTROL2);
+	if (old_timing != MMC_TIMING_MMC_HS400 &&
+	    ios->timing == MMC_TIMING_MMC_HS400) {
+		sdhci_writew(host, 0x80, SDHCI_HOST_CONTROL2);
+		sdhci_acpi_amd_hs400_dll(host);
+	}
+}
+
+static const struct sdhci_ops sdhci_acpi_ops_amd = {
+	.set_clock	= sdhci_set_clock,
+	.set_bus_width	= sdhci_set_bus_width,
+	.reset		= sdhci_reset,
+	.set_uhs_signaling = sdhci_set_uhs_signaling,
+};
+
+static const struct sdhci_acpi_chip sdhci_acpi_chip_amd = {
+	.ops = &sdhci_acpi_ops_amd,
+};
+
+static int sdhci_acpi_emmc_amd_probe_slot(struct platform_device *pdev,
+					  const char *hid, const char *uid)
+{
+	struct sdhci_acpi_host *c = platform_get_drvdata(pdev);
+	struct sdhci_host *host   = c->host;
+
+	sdhci_read_caps(host);
+	if (host->caps1 & SDHCI_SUPPORT_DDR50)
+		host->mmc->caps = MMC_CAP_1_8V_DDR;
+
+	if ((host->caps1 & SDHCI_SUPPORT_SDR104) &&
+	    (host->mmc->caps & MMC_CAP_1_8V_DDR))
+		host->mmc->caps2 = MMC_CAP2_HS400_1_8V;
+
+	host->mmc_host_ops.select_drive_strength = amd_select_drive_strength;
+	host->mmc_host_ops.set_ios = amd_set_ios;
+	return 0;
+}
+
+static const struct sdhci_acpi_slot sdhci_acpi_slot_amd_emmc = {
+	.chip   = &sdhci_acpi_chip_amd,
+	.caps   = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE,
+	.quirks = SDHCI_QUIRK_32BIT_DMA_ADDR | SDHCI_QUIRK_32BIT_DMA_SIZE |
+			SDHCI_QUIRK_32BIT_ADMA_SIZE,
+	.probe_slot     = sdhci_acpi_emmc_amd_probe_slot,
+};
+
 struct sdhci_acpi_uid_slot {
 	const char *hid;
 	const char *uid;
@@ -469,6 +546,7 @@ static const struct sdhci_acpi_uid_slot sdhci_acpi_uids[] = {
 	{ "PNP0D40"  },
 	{ "QCOM8051", NULL, &sdhci_acpi_slot_qcom_sd_3v },
 	{ "QCOM8052", NULL, &sdhci_acpi_slot_qcom_sd },
+	{ "AMDI0040", NULL, &sdhci_acpi_slot_amd_emmc },
 	{ },
 };
 
@@ -485,6 +563,7 @@ static const struct acpi_device_id sdhci_acpi_ids[] = {
 	{ "PNP0D40"  },
 	{ "QCOM8051" },
 	{ "QCOM8052" },
+	{ "AMDI0040" },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, sdhci_acpi_ids);