commit 57322d542ffe01076c9df10d38e3ec0a58f9d83a
author ernest.zhang <ernest.zhang@bayhubtech.com> Mon Jul 16 14:26:51 2018 +0800
committer Ulf Hansson <ulf.hansson@linaro.org> Mon Jul 30 14:23:37 2018 +0200
tree 17e2327f1c98902e4ca887ef2deda61741987f7d
parent 44350993d01c901cc201ef2663fd0fded2e03d06

mmc: sdhci: Add support for O2 eMMC HS200 mode

When use eMMC as boot device, the eMMC signaling voltage is tied to 1.8v
fixed output voltage, bios can set o2 sd host controller PCI configuration
register 0x308 bit4 to 1 to let driver skip 3.3v signaling voltage and
direct use 1.8v singling voltage in eMMC initialize process.

Signed-off-by: ernest.zhang <ernest.zhang@bayhubtech.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pci-o2micro.c

diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c
index 555970a..ba59db6a 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -3,6 +3,7 @@
  *
  * Authors: Peter Guo <peter.guo@bayhubtech.com>
  *          Adam Lee <adam.lee@canonical.com>
+ *          Ernest Zhang <ernest.zhang@bayhubtech.com>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
@@ -39,6 +40,7 @@
 #define O2_SD_MISC_CTRL4	0xFC
 #define O2_SD_TUNING_CTRL	0x300
 #define O2_SD_PLL_SETTING	0x304
+#define O2_SD_MISC_SETTING	0x308
 #define O2_SD_CLK_SETTING	0x328
 #define O2_SD_CAP_REG2		0x330
 #define O2_SD_CAP_REG0		0x334
@@ -184,6 +186,7 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
 	struct sdhci_pci_chip *chip;
 	struct sdhci_host *host;
 	u32 reg;
+	int ret;
 
 	chip = slot->chip;
 	host = slot->host;
@@ -197,6 +200,21 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
 		if (reg & 0x1)
 			host->quirks |= SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12;
 
+		if (chip->pdev->device == PCI_DEVICE_ID_O2_SEABIRD0) {
+			ret = pci_read_config_dword(chip->pdev,
+						    O2_SD_MISC_SETTING, &reg);
+			if (ret)
+				return -EIO;
+			if (reg & (1 << 4)) {
+				pr_info("%s: emmc 1.8v flag is set, force 1.8v signaling voltage\n",
+					mmc_hostname(host->mmc));
+				host->flags &= ~SDHCI_SIGNALING_330;
+				host->flags |= SDHCI_SIGNALING_180;
+				host->mmc->caps2 |= MMC_CAP2_NO_SD;
+				host->mmc->caps2 |= MMC_CAP2_NO_SDIO;
+			}
+		}
+
 		if (chip->pdev->device != PCI_DEVICE_ID_O2_FUJIN2)
 			break;
 		/* set dll watch dog timer */