Re: [PATCH 00/16] omap_hsmmc: Add ADMA support and UHS/HS200/DDR support

[Ulf Hansson <ulf.hansson@linaro.org>]

On 16 June 2017 at 14:45, Kishon Vijay Abraham I <kishon@ti.com> wrote:
> This is the final part of the series originally sent as
> part of [2].
>
> This series adds UHS, HS200, DDR mode and ADMA support to
> omap_hsmmc driver used to improve the throughput of MMC/SD in dra7
> SoCs.
>
> Changes from [2]:
> *) No more updating omap2plus_defconfig or multi_v7_defconfig is
>    required, so those patches are removed.
> *) Addressed Rob Herring's comment on implementing a function
>    instead of having a macro while getting pinctrl state.
>
> This series is created on top of [3], [4], [5] AND [6]
> (i.e after
>   ARM: dts: omap3-overo: Remove "vqmmc-supply" property from MMC dt node
>   omap_hsmmc: use mmc_regulator_get_supply() to get regulators
>   omap*: Fixes/Cleanups for MMC devicetree node
>   ARM: dts: Add iodelay data for MMC)
>
> The functionality implemented in this series was sent before ([1]) but
> was never followed up since supporting high speed modes in dra7 required
> IODelay values to be configured. With IODelay driver being merged into
> kernel, sending it as a fresh series with support for configuring IODelay
> values.

Is it safe to queue this via mmc tree for 4.14 or is there a
dependency I must consider? The above didn't quite tell me that, could
you please elaborate.

>
> Suggestions of migrating to sdhci driver (from omap_hsmmc driver) is not
> addressed since
> *) tuning ratio of MMC in dra7 is different from sdhci
> *) IOdelay is required for dra7
> *) GPIO based card detect is not supported in sdhci

Lots of sdhci drivers calls mmc_of_parse(), and uses the mmc slot gpio
APIs, so I don't this this is correct statement.

> *) Some of the registers don't always have correct values as in sdhci
>    (like PSTATE).
> Supporting all of these in sdhci will result in adding lot of quirks in
> sdhci driver.

Is it really that much different? It would be nice if some really took
on the challenge of converting omap_hsmmc into an sdhci variant.

Especially by looking at the number new lines added in this series, I
am starting to think that we have reached this point. That in
conjunction with that sdhci is maintained and well supported,
comparing to what the omap_hsmmc driver seems to be.

>
> This series has been tested on beagleboard, pandaboard, beaglebone-black,
> beaglebone, am335x-evm, am437x-evm, dra7xx-evm, dra72x-evm, am571x-idk
> and am572x-idk.
>
> I can split the series to go into Ulf Hansson's tree and Tony's tree
> separately if that is required.
>
> [1] -> https://lkml.org/lkml/2015/8/25/213
> [2] -> https://lkml.org/lkml/2017/5/19/19
>
> [3] -> https://lkml.org/lkml/2017/6/9/206
> [4] -> https://lkml.org/lkml/2017/6/7/169
> [5] -> https://www.spinics.net/lists/arm-kernel/msg586215.html /
>        http://www.spinics.net/lists/devicetree/msg180747.html
> [6] -> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1423381.html
>
> Kishon Vijay Abraham I (15):
>   mmc: host: omap_hsmmc: Support pbias and vmmc_aux to switch to 1.8v
>   mmc: host: omap_hsmmc: Separate setting voltage capabilities from bus
>     power
>   mmc: host: omap_hsmmc: Remove incorrect voltage switch sequence
>   mmc: host: omap_hsmmc: Add voltage switch support for UHS SD card
>   mmc: host: omap_hsmmc: Set clk rate to the max frequency
>   mmc: host: omap_hsmmc: Add tuning support
>   mmc: host: omap_hsmmc: Allow io voltage switch even for fixed vdd
>   mmc: host: omap_hsmmc: Prepare *set_timing() to be used for iodelay
>     setting
>   mmc: host: omap_hsmmc: Add new compatible string to support dra7
>   mmc: host: omap_hsmmc: Fix error path sequence
>   mmc: host: omap_hsmmc: Add support to set IODELAY values
>   mmc: host: omap_hsmmc: Remove *use_dma* member
>   mmc: host: omap_hsmmc: Enable ADMA2
>   ARM: dts: dra7: Use new dra7-specific compatible string
>   ARM: dts: dra7: Add supported MMC/SD modes in MMC dt nodes
>
> Mugunthan V N (1):
>   mmc: host: omap_hsmmc: Add software timer when timeout greater than
>     hardware capablility
>
>  .../devicetree/bindings/mmc/ti-omap-hsmmc.txt      |    6 +
>  arch/arm/boot/dts/am571x-idk.dts                   |    1 +
>  arch/arm/boot/dts/am57xx-beagle-x15-revb1.dts      |    1 +
>  arch/arm/boot/dts/am57xx-beagle-x15.dts            |    6 +
>  arch/arm/boot/dts/am57xx-idk-common.dtsi           |    1 +
>  arch/arm/boot/dts/dra7.dtsi                        |   22 +-
>  drivers/mmc/host/omap_hsmmc.c                      | 1179 ++++++++++++++++----
>  include/linux/platform_data/hsmmc-omap.h           |    2 +
>  8 files changed, 1021 insertions(+), 197 deletions(-)
>
> --
> 2.11.0
>

Kind regards
Ulf Hansson