linux-toradex.git/drivers/mmc/core/host.h, branch v6.8

mmc: host: factor out clearing the retune state

2021-08-24T08:15:28+00:00

We have this in two places, so let's have a dedicated function. It is
also more readable.

Signed-off-by: Wolfram Sang 
Acked-by: Adrian Hunter 
Reviewed-by: Yoshihiro Shimoda 
Tested-by: Yoshihiro Shimoda 
Link: https://lore.kernel.org/r/20210624151616.38770-4-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson

mmc: core: Initial support for SD express card/host

2020-11-16T10:59:28+00:00

In the SD specification v7.10 the SD express card has been added. This new
type of removable SD card, can be managed via a PCIe/NVMe based interface,
while also allowing backwards compatibility towards the legacy SD
interface.

To keep the backwards compatibility, it's required to start the
initialization through the legacy SD interface. If it turns out that the
mmc host and the SD card, both supports the PCIe/NVMe interface, then a
switch should be allowed.

Therefore, let's introduce some basic support for this type of SD cards to
the mmc core. The mmc host, should set MMC_CAP2_SD_EXP if it supports this
interface and MMC_CAP2_SD_EXP_1_2V, if also 1.2V is supported, as to inform
the core about it.

To deal with the switch to the PCIe/NVMe interface, the mmc host is
required to implement a new host ops, ->init_sd_express(). Based on the
initial communication between the host and the card, host->ios.timing is
set to either MMC_TIMING_SD_EXP or MMC_TIMING_SD_EXP_1_2V, depending on if
1.2V is supported or not. In this way, the mmc host can check these values
in its ->init_sd_express() ops, to know how to proceed with the handover.

Note that, to manage card insert/removal, the mmc core sticks with using
the ->get_cd() callback, which means it's the host's responsibility to make
sure it provides valid data, even if the card may be managed by PCIe/NVMe
at the moment. As long as the card seems to be present, the mmc core keeps
the card powered on.

Cc: Greg Kroah-Hartman 
Cc: Arnd Bergmann 
Cc: Christoph Hellwig 
Cc: Rui Feng 
Signed-off-by: Ulf Hansson 
Reviewed-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/1603936636-3126-1-git-send-email-rui_feng@realsil.com.cn

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

mmc: core: Don't try UHS-I mode if 4-bit mode isn't supported

2018-03-15T08:30:39+00:00

Per SD specification physical layer v4.0, section 3.9.4, it
says "UHS-I supports only 4-bit mode. Host shall select 4-bit
mode by ACMD6. However mmc_sd_init_uhs_card() still go ahead
to initialize the cards anyway, whether card or host won't
support 4-bit mode.

  This breaks the platforms which could support UHS-I mode but on
some certain boards only support 1-bit mode with a UHS-I card inserted,
as all the tuning process is broken due to this. Alternatively, we
should check the return value from mmc_set_bus_width() to see if host
could finish the request to switch the bus width on its side. But that
needs more thing to do than this patch that just bails out early to try
high speed mode if 4-bit mode isn't available for whatever reason. And
this patch could also fix the same problem for sdio since R4_18V_PRESENT
won't be set for ocr when mmc_sdio_init_card() finds mmc_host_uhs()
is false.

  Note that this patch doesn't keep the checking of card->scr.sda_spec3
and comparing card->scr.bus_widths with SD_SCR_BUS_WIDTH_4 within
mmc_sd_init_uhs_card() since if the sd cards response with SD_ROCR_S18A,
it definitely supports UHS-I mode, which implicitly means these checkings
are always true.

Signed-off-by: Shawn Lin 
Signed-off-by: Ulf Hansson

mmc: core: Remove code no longer needed after the switch to blk-mq

2017-12-11T12:05:58+00:00

Remove code no longer needed after the switch to blk-mq.

Signed-off-by: Adrian Hunter 
Acked-by: Linus Walleij 
Tested-by: Linus Walleij 
Signed-off-by: Ulf Hansson

mmc: core: Remove option not to use blk-mq

2017-12-11T11:55:02+00:00

Remove config option MMC_MQ_DEFAULT and parameter mmc_use_blk_mq, so that
blk-mq must be used always.

Signed-off-by: Adrian Hunter 
Acked-by: Linus Walleij 
Tested-by: Linus Walleij 
Signed-off-by: Ulf Hansson

mmc: block: blk-mq: Add support for direct completion

2017-12-11T11:44:35+00:00

For blk-mq, add support for completing requests directly in the ->done
callback. That means that error handling and urgent background operations
must be handled by recovery_work in that case.

Signed-off-by: Adrian Hunter 
Acked-by: Linus Walleij 
Signed-off-by: Ulf Hansson 
Tested-by: Linus Walleij

mmc: core: Add parameter use_blk_mq

2017-12-11T11:44:33+00:00

Until mmc has blk-mq support fully implemented and tested, add a parameter
use_blk_mq, set to true if config option MMC_MQ_DEFAULT is selected, which
it is by default.

Signed-off-by: Adrian Hunter 
Acked-by: Linus Walleij 
Signed-off-by: Ulf Hansson 
Tested-by: Linus Walleij

mmc: core: Export a few functions needed for blkmq support

2017-10-30T10:45:56+00:00

The following functions are needed by the mmc block device driver, once it
converts to blkmq, therefore let's export them.

mmc_start_bkops()
mmc_start_request()
mmc_retune_hold_now()
mmc_retune_release()

Signed-off-by: Adrian Hunter 
Reviewed-by: Linus Walleij 
Signed-off-by: Ulf Hansson

mmc: core: Add mmc_retune_hold_now()

2017-08-30T12:02:01+00:00

mmc_return_hold() / mmc_retune_release() are used around a group of
commands to prevent re-tuning between the commands. Re-tuning can still
happen before the first command. In some cases, re-tuning must be
prevented entirely. Add mmc_retune_hold_now() for that purpose. It is
added in preparation for CQE support where it will be used by CQE recovery.

Signed-off-by: Adrian Hunter 
Reviewed-by: Linus Walleij 
Signed-off-by: Ulf Hansson