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.
Changes in V5:
Modify code format to pass checkpatch.pl check and add a summary
of what has changed in each version.
Changes in V4:
Skip SDIO and SD initalization when register 0x308 bit 4 is set,
and modify some typo.
Changes in V3:
Rebase the patch on the mmc tree 'next' branch.
Changes in V2:
Modify code format, and delete unused code path.
Changes in V1:
Check PCIe register 0x308 bit 4 and skip eMMC 3.3v initialization
process if it is set to 1.
Signed-off-by: ernest.zhang <[email protected]>
---
drivers/mmc/host/sdhci-pci-o2micro.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
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 <[email protected]>
* Adam Lee <[email protected]>
+ * Ernest Zhang <[email protected]>
*
* 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, ®);
+ 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 */
--
2.7.4
