The main goal of the change is to remove .pin_config_dbg_parse_modify
callback before a driver with its support appears. So far the in-kernel
interface did not attract any users since its introduction 5 years ago.

Originally .pin_config_dbg_parse_modify callback and the associated
'pinconf-config' debugfs file were introduced in commit f07512e615dd
("pinctrl/pinconfig: add debug interface"), a short description of
'pinconf-config' usage for debugging can be expressed this way:

Write to 'pinconf-config' (see pinconf_dbg_config_write() function):

% echo -n modify $map_type $device_name $state_name $pin_name $config > \
	/sys/kernel/debug/pinctrl/$pinctrl/pinconf-config

It supposes to update a global (therefore single!) 'pinconf_dbg_conf'
variable with an alternative setting, the arguments should match
an existing pinconf device and some registered pinctrl mapping 'map':

* $map_type is either 'config_pin' or 'config_group', it should match
  'map->type' value of PIN_MAP_TYPE_CONFIGS_PIN or
   PIN_MAP_TYPE_CONFIGS_GROUP accordingly,
* $device_name should match 'map->dev_name' string value,
* $state_name should match 'map->name' string value,
* $pin_name should match 'map->data.configs.group_or_pin' string value,

If all above has matched, then $config is a new value to be set by calling
pinconfops->pin_config_dbg_parse_modify(pctldev, config, matched_config).

After a successful write into 'pinconf-config' a user can read the file
to get information about that single modified pin configuration.

The fact is .pin_config_dbg_parse_modify callback has never been defined
in 'struct pinconf_ops' of any pinconf driver, thus an actual modification
of a pin or group state on any present pinconf controller does not happen,
and it declares that all related code is no more than dead code.

I discovered the issue while attempting to add .pin_config_dbg_parse_modify
support in some drivers and found that too short 'MAX_NAME_LEN' set by

  drivers/pinctrl/pinconf.c:372:#define MAX_NAME_LEN 15

is practically insufficient to store a regular pinctrl device name,
which are like 'e6060000.pin-controller-sh-pfc' or pin names like
'MX6QDL_PAD_ENET_REF_CLK', thus it is another indicator that the code
is barely usable, insufficiently tested and unprepossessing.

Of course it might be possible to increase MAX_NAME_LEN, and then add
.pin_config_dbg_parse_modify callbacks to the drivers, but the whole
idea of such a limited debug option looks inviable. A more flexible
way to functionally substitute the original approach is to implicitly
or explicitly use pinctrl_select_state() function whenever needed.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Laurent Meunier <laurent.meunier@st.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The change adds explicit inclusion of linux/pinctrl/machine.h header
to the only needed pinctrl-madera-core.c file, and therefore inclusion
of pinctrl/machine.h header from pinctrl/pinconf.h can be removed.

The change is preparatory to a follow-up reversal of commit f07512e615dd
("pinctrl/pinconfig: add debug interface").

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The pinconf_generic_dump_one() function makes the assumption that
pin_config_group_get() should return -EINVAL and -ENOTSUPP just like
pin_config_get() does.  Document that so it's more obvious.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

When setting pin configuration in the pinctrl framework, pin_config_set() or
pin_config_group_set() is called in a loop to set one configuration at a time
for the specified pin or group.

This patch 1) removes the loop and 2) changes the API to pass the whole pin
config array to the driver.  It is now up to the driver to loop through the
configs.  This allows the driver to potentially combine configs and reduce the
number of writes to pin config registers.

All c files changed have been build-tested to verify the change compiles and
that the corresponding .o is successfully generated.

Signed-off-by: Sherman Yin <syin@broadcom.com>
Reviewed-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The kerneldoc comment for struct pinconf_ops was missing
pin_config_dbg_parse_modify, and instead described
pin_config_group_dbg_set (which is presumably an old name for the same
function). Rename it in the kerneldoc comment so they match.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This update adds a debugfs interface to modify a pin configuration
for a given state in the pinctrl map. This allows to modify the
configuration for a non-active state, typically sleep state.
This configuration is not applied right away, but only when the state
will be entered.

This solution is mandated for us by HW validation: in order
to test and verify several pin configurations during sleep without
recompiling the software.

Change log in this patch set;
Take into account latest feedback from Stephen Warren:
- stale comments update
- improved code efficiency and readibility
- limit size of global variable pinconf_dbg_conf
- remove req_type as it can easily be added later when
add/delete requests support is implemented

Signed-off-by: Laurent Meunier <laurent.meunier@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This removes a repeated word and a repeated and incomplete line from two
pinctrl headers.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add a pinconf op so that pin controller drivers can decode their pin
config settings for debugfs.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a split-off from the earlier patch set which adds generic
pin configuration for the pin controllers that want it. Since
we may have a system with mixed generic and custom pin controllers,
we pass a boolean in the pin controller ops vtable to indicate
if it is generic.

ChangeLog v1->v5:
- Follow parent patch versioning number system.
- Document the semantic meaning of return values from pin config
  get functions, so we can iterate over pins and check their
  properties from debugfs as part of the generic config code.
- Use proper cast functions in the generic debugfs pin config
  file.
- Expand generic config to optionally cover groups too.
ChangeLog v5->v6:
- Update to match underlying changes.
ChangeLog v6->v7:
- Drop DRIVE_OFF parameter, use bias high impedance for this
- Delete argument for drive modes push-pull, od and os. These
  are now just state transitions.
- Delete slew rate rising/falling due to discussions on on
  proper semantics
- Drop config wakeup, struct irq_chip does this for now, add
  back if need be.
- Set PIN_CONFIG_END to 0x7fff making room for custom config
  parameters from 0x8000 and up.
- Prefix accessor functions with pinconf_

This breaks out a <linux/pinctrl/consumer.h> header to be used by
all pinmux and pinconfig alike, so drivers needing services from
pinctrl does not need to include different headers. This is similar
to the approach taken by the regulator API.

Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>