Commit Graph

23 Commits

Author SHA1 Message Date
NeilBrown c7ea834d81 mmc: slot-gpio: Allow host driver to provide isr for card-detect interrupts
One of the reasons omap_hsmmc doesn't use the slot-gpio library
is that it has some non-standard functionality in the card-detect
interrupt service routine.

To make it possible for omap_hsmmc (and maybe others) to be converted
to use slot-gpio, add 'mmc_gpio_request_cd_isr' which provide an
alternate isr to be register by the slot-gpio code.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:29 +01:00
Ulf Hansson df8aca162e mmc: slot-gpio: Rework how to handle allocation of slot-gpio data
By moving the allocation of the slot-gpio data into mmc_alloc_host(),
we can remove the slot-gpio internal calls to mmc_gpio_alloc().

This means mmc_gpio_alloc() has now only one caller left, which
consequence allow us to simplify and remove some of the slot-gpio code.

Additionally, this makes the slot-gpio mutex redundant, so let's remove
it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:18 +01:00
Ulf Hansson 7f133de1fb mmc: slot-gpio: Make mmc_gpio_alloc() available for MMC core
As a step in moving slot-gpio functions/structs closer to the MMC core,
let's add a local header file for slot-gpio.

In this initial step we move mmc_gpio_alloc() into the header file,
to make it available for the MMC core. Following patches will show the
utilization of it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:17 +01:00
Ulf Hansson b4cc580bb6 mmc: slot-gpio: Use the parent device while allocating data
We had a mix of using the class device and the parent device while
allocating data through the devm_* managed functions.

Let's be more consistent and always use the parent device.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:16 +01:00
Ulf Hansson eddbc3abc5 mmc: slot-gpio: Remove option to explicitly free requested CD/WP GPIOs
The slot-gpio uses the devm*_ managed functions. Still it provide APIs
to explicitly free requested CD/WP GPIOs, but these API isn't being
used.

Therefore let's simplify slot-gpio by removing these unused APIs. If it
later turns out we need some of them, we can always consider to restore
the code.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:16 +01:00
Linus Walleij 89168b4899 mmc: core: restore detect line inversion semantics
commit 98e90de99a
"mmc: host: switch OF parser to use gpio descriptors"
switched the semantic behaviour of card detect and read
only flags such that the inversion capability flag would
only be set if inversion was explicitly specified in the
device tree, in the hopes that no-one was using double
inversion.

It turns out that the XOR:ing between the explicit
inversion was indeed in use, so we need to restore the
old semantics where both ways of inversion are checked
and the end result XOR:ed.

Reported-by: Javier Martinez Canillas <javier@dowhile0.org>
Tested-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-10-02 11:51:26 +02:00
Adrian Hunter 6800754c36 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>
2014-09-29 11:27:51 +02:00
Stephen Warren d4d1144908 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>
2014-09-23 09:01:36 +02:00
Linus Walleij 9d2fa2428a 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>
2014-09-09 14:25:14 +02:00
Linus Walleij 9fbc695075 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>
2014-09-09 14:25:14 +02:00
Markus Mayer fa372a51cb 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>
2014-04-22 07:06:36 -04:00
Adrian Hunter 740a221ef0 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>
2014-03-17 09:12:00 -04:00
Adrian Hunter 2665267133 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>
2014-03-17 09:11:53 -04:00
Adrian Hunter 842f4bdd37 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>
2014-03-17 09:11:46 -04:00
Laurent Pinchart 214fc309d1 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>
2013-08-24 23:45:09 -04:00
Shawn Guo d65b5ae8da 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>
2013-02-11 12:51:23 -05:00
Guennadi Liakhovetski 451c89578e 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>
2012-12-07 13:55:50 -05:00
Chris Ball 15e8a8e429 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>
2012-09-11 10:55:20 -04:00
Guennadi Liakhovetski 5aa7dad305 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>
2012-07-21 00:02:18 -04:00
Guennadi Liakhovetski a7d1a1ebd8 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>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski befe4048d8 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>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski 27410ee7e3 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>
2012-07-21 00:02:16 -04:00
Guennadi Liakhovetski fd0ea65d3e 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>
2012-07-10 23:04:04 -04:00