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_BUS_HOLD: the pin will be set to weakly latch so that it
  33  *      weakly drives the last value on a tristate bus, also known as a "bus
  34  *      holder", "bus keeper" or "repeater". This allows another device on the
  35  *      bus to change the value by driving the bus high or low and switching to
  36  *      tristate. The argument is ignored.
  37  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
  38  *      impedance to VDD). If the argument is != 0 pull-up is enabled,
  39  *      if it is 0, pull-up is total, i.e. the pin is connected to VDD.
  40  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
  41  *      impedance to GROUND). If the argument is != 0 pull-down is enabled,
  42  *      if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
  43  * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
  44  *      on embedded knowledge of the controller hardware, like current mux
  45  *      function. The pull direction and possibly strength too will normally
  46  *      be decided completely inside the hardware block and not be readable
  47  *      from the kernel side.
  48  *      If the argument is != 0 pull up/down is enabled, if it is 0, the
  49  *      configuration is ignored. The proper way to disable it is to use
  50  *      @PIN_CONFIG_BIAS_DISABLE.
  51  * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
  52  *      low, this is the most typical case and is typically achieved with two
  53  *      active transistors on the output. Setting this config will enable
  54  *      push-pull mode, the argument is ignored.
  55  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
  56  *      collector) which means it is usually wired with other output ports
  57  *      which are then pulled up with an external resistor. Setting this
  58  *      config will enable open drain mode, the argument is ignored.
  59  * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
  60  *      (open emitter). Setting this config will enable open source mode, the
  61  *      argument is ignored.
  62  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
  63  *      passed as argument. The argument is in mA.
  64  * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
  65  *      affect the pin's ability to drive output.  1 enables input, 0 disables
  66  *      input.
  67  * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
  68  *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
  69  *      schmitt-trigger mode is disabled.
  70  * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
  71  *      schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
  72  *      the threshold value is given on a custom format as argument when
  73  *      setting pins to this mode.
  74  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
  75  *      which means it will wait for signals to settle when reading inputs. The
  76  *      argument gives the debounce time in usecs. Setting the
  77  *      argument to zero turns debouncing off.
  78  * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
  79  *      supplies, the argument to this parameter (on a custom format) tells
  80  *      the driver which alternative power source to use.
  81  * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
  82  *      this parameter (on a custom format) tells the driver which alternative
  83  *      slew rate to use.
  84  * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
  85  *      operation, if several modes of operation are supported these can be
  86  *      passed in the argument on a custom form, else just use argument 1
  87  *      to indicate low power mode, argument 0 turns low power mode off.
  88  * @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
  89  *      1 to indicate high level, argument 0 to indicate low level. (Please
  90  *      see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
  91  *      discussion around this parameter.)
  92  * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
  93  *      you need to pass in custom configurations to the pin controller, use
  94  *      PIN_CONFIG_END+1 as the base offset.
  95  */
  96 enum pin_config_param {
  97         PIN_CONFIG_BIAS_DISABLE,
  98         PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
  99         PIN_CONFIG_BIAS_BUS_HOLD,
 100         PIN_CONFIG_BIAS_PULL_UP,
 101         PIN_CONFIG_BIAS_PULL_DOWN,
 102         PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
 103         PIN_CONFIG_DRIVE_PUSH_PULL,
 104         PIN_CONFIG_DRIVE_OPEN_DRAIN,
 105         PIN_CONFIG_DRIVE_OPEN_SOURCE,
 106         PIN_CONFIG_DRIVE_STRENGTH,
 107         PIN_CONFIG_INPUT_ENABLE,
 108         PIN_CONFIG_INPUT_SCHMITT_ENABLE,
 109         PIN_CONFIG_INPUT_SCHMITT,
 110         PIN_CONFIG_INPUT_DEBOUNCE,
 111         PIN_CONFIG_POWER_SOURCE,
 112         PIN_CONFIG_SLEW_RATE,
 113         PIN_CONFIG_LOW_POWER_MODE,
 114         PIN_CONFIG_OUTPUT,
 115         PIN_CONFIG_END = 0x7FFF,
 116 };
 117
 118 /*
 119  * Helpful configuration macro to be used in tables etc.
 120  */
 121 #define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL))
 122
 123 /*
 124  * The following inlines stuffs a configuration parameter and data value
 125  * into and out of an unsigned long argument, as used by the generic pin config
 126  * system. We put the parameter in the lower 16 bits and the argument in the
 127  * upper 16 bits.
 128  */
 129
 130 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
 131 {
 132         return (enum pin_config_param) (config & 0xffffUL);
 133 }
 134
 135 static inline u16 pinconf_to_config_argument(unsigned long config)
 136 {
 137         return (enum pin_config_param) ((config >> 16) & 0xffffUL);
 138 }
 139
 140 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
 141                                                      u16 argument)
 142 {
 143         return PIN_CONF_PACKED(param, argument);
 144 }
 145
 146 #ifdef CONFIG_OF
 147
 148 #include <linux/device.h>
 149 #include <linux/pinctrl/machine.h>
 150 struct pinctrl_dev;
 151 struct pinctrl_map;
 152
 153 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 154                 struct device_node *np, struct pinctrl_map **map,
 155                 unsigned *reserved_maps, unsigned *num_maps,
 156                 enum pinctrl_map_type type);
 157 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 158                 struct device_node *np_config, struct pinctrl_map **map,
 159                 unsigned *num_maps, enum pinctrl_map_type type);
 160
 161 static inline int pinconf_generic_dt_node_to_map_group(
 162                 struct pinctrl_dev *pctldev, struct device_node *np_config,
 163                 struct pinctrl_map **map, unsigned *num_maps)
 164 {
 165         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
 166                         PIN_MAP_TYPE_CONFIGS_GROUP);
 167 }
 168
 169 static inline int pinconf_generic_dt_node_to_map_pin(
 170                 struct pinctrl_dev *pctldev, struct device_node *np_config,
 171                 struct pinctrl_map **map, unsigned *num_maps)
 172 {
 173         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
 174                         PIN_MAP_TYPE_CONFIGS_PIN);
 175 }
 176
 177 #endif
 178
 179 #endif /* CONFIG_GENERIC_PINCONF */
 180
 181 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */