On 10 January 2018 at 16:32, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> On Intel Edison the Broadcom WiFi card, which is connected to SDIO,
> requires 2.0v, while the host, according to Intel Merrifield TRM,
> supports 1.8v supply only.
>
> The card announces itself as
>
> mmc2: new ultra high speed DDR50 SDIO card at address 0001
>
> Introduce a custom OCR mask and ->set_power() callback to override 2.0v
> supply on Intel Merrifield platforms by enforcing 1.8v power choice.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> - address comments given by Adrian
> drivers/mmc/host/sdhci-pci-core.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 3e4f04fd5175..24c2b2504b3f 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -778,6 +778,8 @@ static int intel_mrfld_mmc_probe_slot(struct sdhci_pci_slot *slot)
> slot->host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> break;
> case INTEL_MRFLD_SDIO:
> + /* Advertise 2.0v for compatibility with the SDIO card's OCR */
> + slot->host->ocr_mask = MMC_VDD_20_21 | MMC_VDD_165_195;
> slot->host->mmc->caps |= MMC_CAP_NONREMOVABLE |
> MMC_CAP_POWER_OFF_CARD;
> break;
> @@ -789,10 +791,35 @@ static int intel_mrfld_mmc_probe_slot(struct sdhci_pci_slot *slot)
> return 0;
> }
>
> +static void intel_mrfld_sdhci_set_power(struct sdhci_host *host,
> + unsigned char mode, unsigned short vdd)
> +{
> + /*
> + * Without a regulator, SDHCI does not support 2.0v but we get
> + * here because we advertised 2.0v support for compatibility
> + * with the SDIO card's OCR. Map it to 1.8v for the purpose of
> + * turning on the power.
> + */
> + if (IS_ERR(host->mmc->supply.vmmc) && vdd == ilog2(MMC_VDD_20_21))
> + vdd = ilog2(MMC_VDD_165_195);
Why not instead extend the range in sdhci_set_power_noreg() to also
check for MMC_VDD_20_21?
Or is there a problem with that?
> +
> + sdhci_set_power(host, mode, vdd);
> +}
> +
Kind regards
Uffe
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