[PATCH v3 0/2] mmc: sdhci-pci: Use ACPI to set max frequency of sdio host controller

Zach Brown
2016-11-28T19:18:06Z

On some boards, max SDIO frequency is limited by trace lengths and other layout
choices. We would like a way to specify this limitation so the driver can
behave accordingly.

This patch set assumes that the limitation has been reported in an ACPI table
which the driver can check to get the max frequency.

The first patch creates a PCI ID and support for the Intel byt sdio where NI is
the subvendor.

If CONFIG_ACPI is set, the second patch uses the ACPI table to set f_max during
the new ni_byt_sdio_probe_slot.

rv2:
* Use acpi_evaluate_integer() instead of
acpi_get_handle()/acpi_evaluate_object()
pv1:
* Removed redundant comment
* Print info message if MXFQ not found in acpi table
pv2:
* Changed info message to error message if MXFQ not found
* Replaced ni_byt_sdio_probe_slot with one of two versions depending on
whether CONFIG_ACPI is set.
pv3:
* Replaced the two versions of ni_byt_sdio_probe_slot with new version that
calls ni_set_max_freq.
* Created ni_set_max_freq which sets the slot's max_freq if CONFIG_ACPI is
set.

Zach Brown (2):
mmc: sdhci-pci: Add PCI ID for Intel byt sdio host controller
sub-vended by NI
mmc: sdhci-pci: Use ACPI to get max frequency for Intel byt sdio
controller sub-vended by NI

drivers/mmc/host/sdhci-pci-core.c | 56 +++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)

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2.7.4