Re: [PATCH V2 00/11] mmc: Add support for drive strength for eMMCs

Adrian Hunter
2015-05-11T09:31:22Z

On 06/02/15 14:12, Adrian Hunter wrote:
> Hi
>
> Here is V2 of some patches to enable a host controller to select
> driver strength for eMMCs using HS200 or HS400. These are based
> on top of the re-tuning series.
>
> There can be some confusion over the term "driver strength".
> SD calls it "drive strength" for the card but "driver type"
> for the host. Whereas JEDEC calls it both "driver strength"
> and "driver type". The values are the same for both SD
> and eMMC:
>
> Value Driver Type Relative strength
> 0 B x1 default and mandatory support
> 1 A x1.5
> 2 C x0.75
> 3 D x0.5
>
> Except eMMC also defines value 4:
>
> Value Driver Type Relative strength
> 4 x1.2
>
>
> Changes in V2:
>
> mmc: core: Add function to read driver-strength device property
> Dropped because there are still questions over how to use
> device properties.
>
> mmc: sdhci-pci: Add support for drive strength selection for SPT
> Amended to reflect the change above.
>
>
> Adrian Hunter (11):
> mmc: core: Reset driver type to default
> mmc: core: Allow card drive strength to be different to host
> mmc: core: Simplify card drive strength mask
> mmc: core: Add 'card' to drive strength selection callback
> mmc: core: Factor out common code in drive strength selection
> mmc: core: Record card drive strength
> mmc: mmc: Read card's valid driver strength mask
> mmc: mmc: Add driver strength selection
> mmc: sdhci: Add a callback to select drive strength
> mmc: sdhci-pci: Add support for drive strength selection for SPT
> mmc: sdhci-pci: Enable HS400 for some Intel host controllers
>
> drivers/mmc/core/core.c | 39 ++++++++++++++++++
> drivers/mmc/core/core.h | 2 +
> drivers/mmc/core/mmc.c | 46 +++++++++++++++++----
> drivers/mmc/core/sd.c | 69 ++++++++-----------------------
> drivers/mmc/core/sdio.c | 77 +++++++++++-----------------------
> drivers/mmc/host/sdhci-pci-data.c | 3 ++
> drivers/mmc/host/sdhci-pci.c | 84 ++++++++++++++++++++++++++++++++++++++
> drivers/mmc/host/sdhci-pci.h | 4 ++
> drivers/mmc/host/sdhci.c | 13 ++++++
> drivers/mmc/host/sdhci.h | 4 ++
> include/linux/mmc/card.h | 2 +
> include/linux/mmc/host.h | 4 +-
> include/linux/mmc/mmc.h | 4 ++
> include/linux/mmc/sdhci-pci-data.h | 2 +
> 14 files changed, 240 insertions(+), 113 deletions(-)

Hi Ulf

These patches still apply. Would have time to look at them?

Regards
Adrian