On 19 October 2017 at 12:41, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> Some Intel host controllers use an ACPI device-specific method to ensure
> correct voltage switching. Fix voltage switch for those, by adding a call
> to the DSM.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-acpi.c | 108 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 108 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
> index 5bb5880403b2..b988997a1e80 100644
> --- a/drivers/mmc/host/sdhci-acpi.c
> +++ b/drivers/mmc/host/sdhci-acpi.c
> @@ -96,6 +96,105 @@ static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
> return c->slot && (c->slot->flags & flag);
> }
>
> +enum {
> + INTEL_DSM_FNS = 0,
> + INTEL_DSM_V18_SWITCH = 3,
> + INTEL_DSM_V33_SWITCH = 4,
> +};
> +
> +struct intel_host {
> + u32 dsm_fns;
> +};
> +
> +static const guid_t intel_dsm_guid =
> + GUID_INIT(0xF6C13EA5, 0x65CD, 0x461F,
> + 0xAB, 0x7A, 0x29, 0xF7, 0xE8, 0xD5, 0xBD, 0x61);
> +
> +static int __intel_dsm(struct intel_host *intel_host, struct device *dev,
> + unsigned int fn, u32 *result)
> +{
> + union acpi_object *obj;
> + int err = 0;
> +
> + obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &intel_dsm_guid, 0, fn, NULL);
> + if (!obj)
> + return -EOPNOTSUPP;
> +
> + if (obj->type == ACPI_TYPE_INTEGER) {
> + *result = obj->integer.value;
> + } else if (obj->type == ACPI_TYPE_BUFFER && obj->buffer.length > 0) {
> + size_t len = min_t(size_t, obj->buffer.length, 4);
> +
> + *result = 0;
> + memcpy(result, obj->buffer.pointer, len);
> + } else {
> + dev_err(dev, "%s DSM fn %u obj->type %d obj->buffer.length %d\n",
> + __func__, fn, obj->type, obj->buffer.length);
> + err = -EINVAL;
> + }
> +
This hole ACPI thing looks weird. Could perhaps the ACPI core, model
this a vqmmc regulator instead?
That would keep the ACPI specific part closer to ACPI and we can treat
this similar to other mmc host drivers.
> + ACPI_FREE(obj);
> +
> + return err;
> +}
> +
[...]
Kind regards
Uffe
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
