If the optional power-off-delay-us property is found, insert the
corresponding delay after asserting the GPIO during power off. This enables
a graceful shutdown sequence for some devices.
Cc: linux-mmc@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Some devices need a while to boot their firmware after providing clks /
de-asserting resets before they are ready to receive sdio commands.
This commits adds a post-power-on-delay-ms devicetree property to
mmc-pwrseq-simple for use with such devices.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
simple-pwrseq and emmc-pwrseq drivers rely on platform_device
structure from of_find_device_by_node(), this works mostly. But, as there
is no driver associated with this devices, cases like default/init pinctrl
setup would never be performed by pwrseq. This becomes problem when the
gpios used in pwrseq require pinctrl setup.
Currently most of the common pinctrl setup is done in
drivers/base/pinctrl.c by pinctrl_bind_pins().
There are two ways to solve this issue on either convert pwrseq drivers
to a proper platform drivers or copy the exact code from
pcintrl_bind_pins(). I prefer converting pwrseq to proper drivers so that
other cases like setting up clks/parents from dt would also be possible.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds to_pwrseq_simple() macro to make the code more readable.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The DT binding doc says reset-gpios is an optional property but the code
currently bails out if it is omitted.
This is a regression since it breaks previously working device trees.
Fix it by restoring the original documented behaviour.
Fixes: ce03727586 ("mmc: pwrseq_simple: use GPIO descriptors array API")
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The mmc_pwrseq_ops structures are never modified, so declare them as const.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The simple power sequence provider sets a value for multiple GPIOs in one
go so it is better to use the API already provided by the GPIO descriptor
API instead of open coding the same logic.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The alloc() and free() hooks required each pwrseq implementation to set
host->pwrseq themselves. This is error-prone and could be done at a
higher level if alloc() was changed to return a pointer to a struct
mmc_pwrseq instead of an error code.
This patch performs this change and moves the burden of maintaining
host->pwrseq from the power sequence hooks to the pwrseq code.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The current error-path code (when gpiod_get_index() reports
an error) can never free pwrseq->reset_gpios[0], but might
try to tree pwrseq->reset_gpios[-1], which has unfortunate
consequences.
Signed-off-by: NeilBrown <neil@brown.name>
Fixes: 934f1f4833
Acked-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Some WLAN chips attached to a SDIO interface, need a reference clock.
Since this is very common, extend the prseq_simple driver to support
an optional clock that is enabled prior the card power up procedure.
Note: the external clock is optional. Thus an error is not returned
if the clock is not found.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Many WLAN attached to a SDIO/MMC interface, needs more than one pin for
their reset sequence. For example, is very common for chips to have two
pins: one for reset and one for power enable.
This patch adds support for more reset pins to the pwrseq_simple driver
and instead hardcoding a fixed number, it uses the of_gpio_named_count()
since the MMC power sequence is only built when CONFIG_OF is enabled.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The need for reset GPIOs has several times been pointed out from
erlier posted patchsets. Especially some WLAN chips which are
attached to an SDIO interface may use a GPIO reset.
The reset GPIO is asserted at initialization and prior we start the
power up procedure. The GPIO will be de-asserted right after the power
has been provided to the card, from the ->post_power_on() callback.
Note, the reset GPIO is optional. Thus we don't return an error even if
we can't find a GPIO for the consumer.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
To add the core part for the MMC power sequence, let's start by adding
initial support for the simple MMC power sequence provider.
In this initial step, the MMC power sequence node are fetched and the
compatible string for the simple MMC power sequence provider are
verified.
At this point we don't parse the node for any properties, but instead
that will be handled from following patches. Since there are no
properties supported yet, let's just implement the ->alloc() and the
->free() callbacks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Ulf Hansson