include/linux/pinctrl/pinconf-generic.h

   1 /*
   2  * Interface the generic pinconfig portions of the pinctrl subsystem
   3  *
   4  * Copyright (C) 2011 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  * This interface is used in the core to keep track of pins.
   7  *
   8  * Author: Linus Walleij <linus.walleij@linaro.org>
   9  *
  10  * License terms: GNU General Public License (GPL) version 2
  11  */
  12 #ifndef __LINUX_PINCTRL_PINCONF_GENERIC_H
  13 #define __LINUX_PINCTRL_PINCONF_GENERIC_H
  14
  15 /*
  16  * You shouldn't even be able to compile with these enums etc unless you're
  17  * using generic pin config. That is why this is defined out.
  18  */
  19 #ifdef CONFIG_GENERIC_PINCONF
  20
  21 /**
  22  * enum pin_config_param - possible pin configuration parameters
  23  * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
  24  *      transition from say pull-up to pull-down implies that you disable
  25  *      pull-up in the process, this setting disables all biasing.
  26  * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
  27  *      mode, also know as "third-state" (tristate) or "high-Z" or "floating".
  28  *      On output pins this effectively disconnects the pin, which is useful
  29  *      if for example some other pin is going to drive the signal connected
  30  *      to it for a while. Pins used for input are usually always high
  31  *      impedance.
  32  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
  33  *      impedance to VDD). If the argument is != 0 pull-up is enabled,
  34  *      if it is 0, pull-up is disabled.
  35  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
  36  *      impedance to GROUND). If the argument is != 0 pull-down is enabled,
  37  *      if it is 0, pull-down is disabled.
  38  * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
  39  *      low, this is the most typical case and is typically achieved with two
  40  *      active transistors on the output. Sending this config will enabale
  41  *      push-pull mode, the argument is ignored.
  42  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
  43  *      collector) which means it is usually wired with other output ports
  44  *      which are then pulled up with an external resistor. Sending this
  45  *      config will enabale open drain mode, the argument is ignored.
  46  * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
  47  *      (open emitter). Sending this config will enabale open drain mode, the
  48  *      argument is ignored.
  49  * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
  50  *      schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
  51  *      the threshold value is given on a custom format as argument when
  52  *      setting pins to this mode. The argument zero turns the schmitt trigger
  53  *      off.
  54  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
  55  *      which means it will wait for signals to settle when reading inputs. The
  56  *      argument gives the debounce time on a custom format. Setting the
  57  *      argument to zero turns debouncing off.
  58  * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
  59  *      supplies, the argument to this parameter (on a custom format) tells
  60  *      the driver which alternative power source to use.
  61  * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
  62  *      operation, if several modes of operation are supported these can be
  63  *      passed in the argument on a custom form, else just use argument 1
  64  *      to indicate low power mode, argument 0 turns low power mode off.
  65  * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
  66  *      you need to pass in custom configurations to the pin controller, use
  67  *      PIN_CONFIG_END+1 as the base offset.
  68  */
  69 enum pin_config_param {
  70         PIN_CONFIG_BIAS_DISABLE,
  71         PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
  72         PIN_CONFIG_BIAS_PULL_UP,
  73         PIN_CONFIG_BIAS_PULL_DOWN,
  74         PIN_CONFIG_DRIVE_PUSH_PULL,
  75         PIN_CONFIG_DRIVE_OPEN_DRAIN,
  76         PIN_CONFIG_DRIVE_OPEN_SOURCE,
  77         PIN_CONFIG_INPUT_SCHMITT,
  78         PIN_CONFIG_INPUT_DEBOUNCE,
  79         PIN_CONFIG_POWER_SOURCE,
  80         PIN_CONFIG_LOW_POWER_MODE,
  81         PIN_CONFIG_END = 0x7FFF,
  82 };
  83
  84 /*
  85  * Helpful configuration macro to be used in tables etc.
  86  */
  87 #define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL))
  88
  89 /*
  90  * The following inlines stuffs a configuration parameter and data value
  91  * into and out of an unsigned long argument, as used by the generic pin config
  92  * system. We put the parameter in the lower 16 bits and the argument in the
  93  * upper 16 bits.
  94  */
  95
  96 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
  97 {
  98         return (enum pin_config_param) (config & 0xffffUL);
  99 }
 100
 101 static inline u16 pinconf_to_config_argument(unsigned long config)
 102 {
 103         return (enum pin_config_param) ((config >> 16) & 0xffffUL);
 104 }
 105
 106 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
 107                                                      u16 argument)
 108 {
 109         return PIN_CONF_PACKED(param, argument);
 110 }
 111
 112 #endif /* CONFIG_GENERIC_PINCONF */
 113
 114 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */