mmc: Fix use of wrong device in mmc_gpiod_free_cd()

mmc_gpiod_free_cd() is paired with mmc_gpiod_request_cd()
and both must reference the same device which is the
actual host control

mmc: Fix use of wrong device in mmc_gpiod_free_cd()

mmc_gpiod_free_cd() is paired with mmc_gpiod_request_cd()
and both must reference the same device which is the
actual host controller device not the mmc_host class
device.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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mmc: don't request CD IRQ until mmc_start_host()

As soon as the CD IRQ is requested, it can trigger, since it's an
externally controlled event. If it does, delayed_work host->detect will

mmc: don't request CD IRQ until mmc_start_host()

As soon as the CD IRQ is requested, it can trigger, since it's an
externally controlled event. If it does, delayed_work host->detect will
be scheduled.

Many host controller probe()s are roughly structured as:

*_probe() {
host = sdhci_pltfm_init();
mmc_of_parse(host->mmc);
rc = sdhci_add_host(host);
if (rc) {
sdhci_pltfm_free();
return rc;
}

In 3.17, CD IRQs can are enabled quite early via *_probe() ->
mmc_of_parse() -> mmc_gpio_request_cd() -> mmc_gpiod_request_cd_irq().

Note that in linux-next, mmc_of_parse() calls mmc_gpio*d*_request_cd()
rather than mmc_gpio_request_cd(), and mmc_gpio*d*_request_cd() doesn't
call mmc_gpiod_request_cd_irq(). However, this issue still exists if
mmc_gpio_request_cd() is called directly before mmc_start_host().

sdhci_add_host() may fail part way through (e.g. due to deferred
probe for a vmmc regulator), and sdhci_pltfm_free() does nothing to
unrequest the CD IRQ nor cancel the delayed_work. sdhci_pltfm_free() is
coded to assume that if sdhci_add_host() failed, then the delayed_work
cannot (or should not) have been triggered.

This can lead to the following with CONFIG_DEBUG_OBJECTS_* enabled, when
kfree(host) is eventually called inside sdhci_pltfm_free():

WARNING: CPU: 2 PID: 6 at lib/debugobjects.c:263 debug_print_object+0x8c/0xb4()
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x18

The object being complained about is host->detect.

There's no need to request the CD IRQ so early; mmc_start_host() already
requests it. For most SDHCI hosts at least, the typical call path that
does this is: *_probe() -> sdhci_add_host() -> mmc_add_host() ->
mmc_start_host(). Therefore, remove the call to mmc_gpiod_request_cd_irq()
from mmc_gpio_request_cd(). This also matches mmc_gpio*d*_request_cd(),
which already doesn't call mmc_gpiod_request_cd_irq().

However, some host controller drivers call mmc_gpio_request_cd() after
mmc_start_host() has already been called, and assume that this will also
call mmc_gpiod_request_cd_irq(). Update those drivers to explicitly call
mmc_gpiod_request_cd_irq() themselves. Ideally, these drivers should be
modified to move their call to mmc_gpio_request_cd() before their call
to mmc_add_host(). However that's too large a change for stable.

This solves the problem (eliminates the kernel error message above),
since it guarantees that the IRQ can't trigger before mmc_start_host()
is called.

The critical point here is that once sdhci_add_host() calls
mmc_add_host() -> mmc_start_host(), sdhci_add_host() is coded not to
fail. In other words, if there's a chance that mmc_start_host() may have
been called, and CD IRQs triggered, and the delayed_work scheduled,
sdhci_add_host() won't fail, and so cleanup is no longer via
sdhci_pltfm_free() (which doesn't free the IRQ or cancel the work queue)
but instead must be via sdhci_remove_host(), which calls mmc_remove_host()
-> mmc_stop_host(), which does free the IRQ and cancel the work queue.

CC: Russell King <linux@arm.linux.org.uk>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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mmc: slot-gpio: add gpiod variant to get wp GPIO

This makes it possible to get the write protect (read only)
GPIO line from a GPIO descriptor. Written to exactly mirror
the card dete

mmc: slot-gpio: add gpiod variant to get wp GPIO

This makes it possible to get the write protect (read only)
GPIO line from a GPIO descriptor. Written to exactly mirror
the card detect function.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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mmc: slot-gpio: switch to use flags when getting GPIO

When the slot GPIO driver gets the GPIO to be used for card
detect, it is now possible to specify a flag to have the line
set up

mmc: slot-gpio: switch to use flags when getting GPIO

When the slot GPIO driver gets the GPIO to be used for card
detect, it is now possible to specify a flag to have the line
set up as input. Get rid of the explicit setup call for input
and use the flag.

The extra argument works as there are transition varargs
macros in place in the <linux/gpio/consumer.h> header, in
the future we will make the flags argument compulsory.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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mmc: Delay the card_event callback into the mmc_rescan worker

This change removes the callback from atomic context which it doesn't
need to be in, and puts it in line with the debounced

mmc: Delay the card_event callback into the mmc_rescan worker

This change removes the callback from atomic context which it doesn't
need to be in, and puts it in line with the debounced rescan.

This code is based on these e-mail threads with Christian Daudt:

https://lkml.org/lkml/2013/8/19/539
https://lkml.org/lkml/2014/3/19/79

Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

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mmc: slot-gpio: Add GPIO descriptor based CD GPIO API

Add functions to request a CD GPIO using the GPIO descriptor API.
Note that the new request function is paired with mmc_gpiod_free_c

mmc: slot-gpio: Add GPIO descriptor based CD GPIO API

Add functions to request a CD GPIO using the GPIO descriptor API.
Note that the new request function is paired with mmc_gpiod_free_cd()
not mmc_gpio_free_cd(). Note also that it must be called prior to
mmc_add_host() otherwise the caller must also call
mmc_gpiod_request_cd_irq().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

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mmc: slot-gpio: Split out CD IRQ request into a separate function

In preparation for adding a descriptor-based CD GPIO API, split out
CD IRQ request into a separate function.

Si

mmc: slot-gpio: Split out CD IRQ request into a separate function

In preparation for adding a descriptor-based CD GPIO API, split out
CD IRQ request into a separate function.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <chris@printf.net>

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mmc: slot-gpio: Record GPIO descriptors instead of GPIO numbers

In preparation for adding a descriptor-based CD GPIO API, switch from
recording GPIO numbers to recording GPIO descriptors

mmc: slot-gpio: Record GPIO descriptors instead of GPIO numbers

In preparation for adding a descriptor-based CD GPIO API, switch from
recording GPIO numbers to recording GPIO descriptors.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <chris@printf.net>

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mmc: slot-gpio: Add debouncing capability to mmc_gpio_request_cd()

Add a debounce parameter to the mmc_gpio_request_cd() function that
enables GPIO debouncing when set to a non-zero valu

mmc: slot-gpio: Add debouncing capability to mmc_gpio_request_cd()

Add a debounce parameter to the mmc_gpio_request_cd() function that
enables GPIO debouncing when set to a non-zero value. This can be used
by MMC host drivers to enable debouncing on the card detect signal.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: slot-gpio: use devm_* managed functions to ease users

Use devm_* managed functions, so that slot-gpio users do not have to
call mmc_gpio_free_ro/cd to free up resources requested in

mmc: slot-gpio: use devm_* managed functions to ease users

Use devm_* managed functions, so that slot-gpio users do not have to
call mmc_gpio_free_ro/cd to free up resources requested in
mmc_gpio_request_ro/cd.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: extend the slot-gpio card-detection to use host's .card_event() method

The slot-gpio API provides a generic card-detection handler. To support a
wider range of hosts it has to call

mmc: extend the slot-gpio card-detection to use host's .card_event() method

The slot-gpio API provides a generic card-detection handler. To support a
wider range of hosts it has to call the host's card-event callback, if
implemented. Also increase the debounce interval to 200ms to match the
SDHCI driver.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: slot-gpio: Fix missing assignment to ctx->ro_gpio

mmc_gpio_request_ro() doesn't store the requested gpio in ctx->ro_gpio.
As a result, subsequent calls to mmc_gpio_get_ro() will alw

mmc: slot-gpio: Fix missing assignment to ctx->ro_gpio

mmc_gpio_request_ro() doesn't store the requested gpio in ctx->ro_gpio.
As a result, subsequent calls to mmc_gpio_get_ro() will always fail
with -ENOSYS because the gpio number isn't available to that function.

Cc: stable <stable@vger.kernel.org>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: core: add WP pin handler to slot functions

Card Write-Protect pin is often implemented, using a GPIO, which makes
it simple to provide a generic handler for it.

Signed-off-

mmc: core: add WP pin handler to slot functions

Card Write-Protect pin is often implemented, using a GPIO, which makes
it simple to provide a generic handler for it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: core: convert slot functions to managed allocation

This prepares for the addition of further slot functions.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Si

mmc: core: convert slot functions to managed allocation

This prepares for the addition of further slot functions.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: add CD GPIO polling support to slot functions

A simple extension of mmc slot functions add support for CD GPIO polling
for cases where the GPIO cannot produce interrupts, or where t

mmc: add CD GPIO polling support to slot functions

A simple extension of mmc slot functions add support for CD GPIO polling
for cases where the GPIO cannot produce interrupts, or where this is not
desired for some reason.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: core: use a more generic name for slot function types and fields

struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.

Signed-off-b

mmc: core: use a more generic name for slot function types and fields

struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions

GPIOs can be used in MMC/SD-card slots not only for hotplug detection, but
also to implement the write-protectio

mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions

GPIOs can be used in MMC/SD-card slots not only for hotplug detection, but
also to implement the write-protection pin. Rename cd-gpio helpers to
slot-gpio to make addition of further slot GPIO functions possible.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

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