talos-obmc-linux/include/linux/pinctrl, branch dev-4.10

gpio: gpiolib: Generalise state persistence beyond sleep

2018-01-16T17:54:29+00:00

General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery Reviewed-by: Charles Keepax Acked-by: Rob Herring Signed-off-by: Linus Walleij (cherry picked from commit e10f72bf4b3e8885c1915a119141481e7fc45ca8) Signed-off-by: Joel Stanley

pinctrl / gpio: Introduce .set_config() callback for GPIO chips

2017-04-27T05:03:49+00:00

Currently we already have two pin configuration related callbacks available for GPIO chips .set_single_ended() and .set_debounce(). In future we expect to have even more, which does not scale well if we need to add yet another callback to the GPIO chip structure for each possible configuration parameter. Better solution is to reuse what we already have available in the generic pinconf. To support this, we introduce a new .set_config() callback for GPIO chips. The callback takes a single packed pin configuration value as parameter. This can then be extended easily beyond what is currently supported by just adding new types to the generic pinconf enum. If the GPIO driver is backed up by a pinctrl driver the GPIO driver can just assign gpiochip_generic_config() (introduced in this patch) to .set_config and that will take care configuration requests are directed to the pinctrl driver. We then convert the existing drivers over .set_config() and finally remove the .set_single_ended() and .set_debounce() callbacks. Suggested-by: Linus Walleij Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij (cherry picked from commit 2956b5d94a76b596fa5057c2b3ca915cb27d7652) Signed-off-by: Joel Stanley

pinctrl: Allow configuration of pins from gpiolib based drivers

2017-04-27T05:03:48+00:00

When a GPIO driver is backed by a pinctrl driver the GPIO driver sometimes needs to call the pinctrl driver to configure certain things, like whether the pin is used as input or output. In addition to this there are other configurations applicable to GPIOs such as setting debounce time of the GPIO. To support this we introduce a new function pinctrl_gpio_set_config() that can be used by gpiolib based driver to pass configuration requests to the backing pinctrl driver. Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij (cherry picked from commit 15381bc7c7f52d56f87c56dd7c948ad78704b852) Signed-off-by: Joel Stanley

pinctrl: pinconf: Add generic helper function for freeing mappings

2016-06-23T09:18:56+00:00

The pinconf-generic.h file exposes functions for creating generic mappings but it does not expose a function for freeing the mappings. Add a function for freeing generic mappings. Signed-off-by: Jon Hunter Signed-off-by: Linus Walleij

pinctrl: Add devm_ apis for pinctrl_{register, unregister}

2016-04-20T22:01:21+00:00

Add device managed APIs devm_pinctrl_register() and devm_pinctrl_unregister() for the APIs pinctrl_register() and pinctrl_unregister(). This helps in reducing code in error path and sometimes removal of .remove callback for driver unbind. Signed-off-by: Laxman Dewangan Reviewed-by: Philipp Zabel Acked-by: Bjorn Andersson Signed-off-by: Linus Walleij

drivers/pinctrl: Add the concept of an "init" state

2015-10-27T10:24:23+00:00

For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson Acked-by: Greg Kroah-Hartman Tested-by: Caesar Wang Signed-off-by: Linus Walleij

pinctrl: pinconf-generic: sort pin configuration params alphabetically

2015-10-02T22:07:27+00:00

Currently, the dt_params array in drivers/pinctrl/pinconf-generic.c is not sorted in the same order as the enum pin_config_param in include/linux/pinctrl/pinconf-generic.h. Sort enum pin_config_param, conf_items, dt_params, alphabetically for consistency. Signed-off-by: Masahiro Yamada Signed-off-by: Linus Walleij

pinctrl: use "const struct ..." rather than "struct ... const"

2015-06-01T13:48:12+00:00

Only this member, pins, is defined as "struct ... const *", but the others in this struct, pinlops, pmxops, confops, etc. are defined as "const struct ... *". Swap the "struct pinctrl_pin_desc" and "const" for consistency. Signed-off-by: Masahiro Yamada Signed-off-by: Linus Walleij

pinctrl: remove useless const qualifier

2015-06-01T13:47:20+00:00

This "const" claims the get_function_groups callback never changes the given num_groups pointer. It is always true in C language, so not worth mentioning. Signed-off-by: Masahiro Yamada Signed-off-by: Linus Walleij

pinctrl: use ERR_CAST instead of ERR_PTR/PTR_ERR

2015-05-06T13:34:51+00:00

Inspired by scripts/coccinelle/api/err_cast.cocci Signed-off-by: Fabian Frederick Signed-off-by: Linus Walleij