Re: [PATCH V4 1/3] mmc: sdhci: Add support for O2 eMMC HS200 mode

From: Adrian Hunter
Date: Thu Mar 29 2018 - 08:26:52 EST


On 09/03/18 16:04, ernest.zhang wrote:
> 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: Check PCIe register 0x308 bit 4 and skip eMMC 3.3v initialization
> process if it is set to 1.
>
> Signed-off-by: ernest.zhang <ernest.zhang@xxxxxxxxxxxxxx>

Notwithstanding minor formatting comment below:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> 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..d465751 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@xxxxxxxxxxxxxx>
> * Adam Lee <adam.lee@xxxxxxxxxxxxx>
> + * Ernest Zhang <ernest.zhang@xxxxxxxxxxxxxx>
> *
> * 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));

Indenting is a little odd i.e. checkpatch says

CHECK: Alignment should match open parenthesis
#58: FILE: drivers/mmc/host/sdhci-pci-o2micro.c:210:
+ 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 */
>