On 05/01/18 22:37, Andy Shevchenko 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 I/O only.
I/O -> supply
>
> 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
> signaling on Intel Merrifield platforms by enforcing 1.8v power choice.
signaling -> supply
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> - quirk free approach
> drivers/mmc/host/sdhci-pci-core.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 3e4f04fd5175..029fcb19eb91 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -778,6 +778,7 @@ 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:
Maybe add a comment here:
/* 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 +790,37 @@ 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)
> +{
> + if (IS_ERR(host->mmc->supply.vmmc)) {
> + switch (1 << vdd) {
Maybe add a comment:
/*
* 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.
*/
> + case MMC_VDD_20_21:
> + sdhci_set_power_noreg(host, mode, ilog2(MMC_VDD_165_195));
> + break;
> + default:
> + sdhci_set_power_noreg(host, mode, vdd);
> + break;
> + }
> + } else {
> + sdhci_set_power(host, mode, vdd);
> + }
How about this instead:
if (IS_ERR(host->mmc->supply.vmmc) && vdd == ilog2(MMC_VDD_20_21)) {
sdhci_set_power_noreg(host, mode, ilog2(MMC_VDD_165_195));
return;
}
sdhci_set_power(host, mode, vdd);
> +}
> +
> +static const struct sdhci_ops intel_mrfld_sdhci_pci_ops = {
> + .set_clock = sdhci_set_clock,
> + .set_power = intel_mrfld_sdhci_set_power,
> + .enable_dma = sdhci_pci_enable_dma,
> + .set_bus_width = sdhci_set_bus_width,
> + .reset = sdhci_reset,
> + .set_uhs_signaling = sdhci_set_uhs_signaling,
> +};
> +
> static const struct sdhci_pci_fixes sdhci_intel_mrfld_mmc = {
> .quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
> .quirks2 = SDHCI_QUIRK2_BROKEN_HS200 |
> SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> + .ops = &intel_mrfld_sdhci_pci_ops,
> .allow_runtime_pm = true,
> .probe_slot = intel_mrfld_mmc_probe_slot,
> };
>
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