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  * enum pin_config_param - possible pin configuration parameters
  17  * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
  18  *      weakly drives the last value on a tristate bus, also known as a "bus
  19  *      holder", "bus keeper" or "repeater". This allows another device on the
  20  *      bus to change the value by driving the bus high or low and switching to
  21  *      tristate. The argument is ignored.
  22  * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
  23  *      transition from say pull-up to pull-down implies that you disable
  24  *      pull-up in the process, this setting disables all biasing.
  25  * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
  26  *      mode, also know as "third-state" (tristate) or "high-Z" or "floating".
  27  *      On output pins this effectively disconnects the pin, which is useful
  28  *      if for example some other pin is going to drive the signal connected
  29  *      to it for a while. Pins used for input are usually always high
  30  *      impedance.
  31  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
  32  *      impedance to GROUND). If the argument is != 0 pull-down is enabled,
  33  *      if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
  34  * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
  35  *      on embedded knowledge of the controller hardware, like current mux
  36  *      function. The pull direction and possibly strength too will normally
  37  *      be decided completely inside the hardware block and not be readable
  38  *      from the kernel side.
  39  *      If the argument is != 0 pull up/down is enabled, if it is 0, the
  40  *      configuration is ignored. The proper way to disable it is to use
  41  *      @PIN_CONFIG_BIAS_DISABLE.
  42  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
  43  *      impedance to VDD). If the argument is != 0 pull-up is enabled,
  44  *      if it is 0, pull-up is total, i.e. the pin is connected to VDD.
  45  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
  46  *      collector) which means it is usually wired with other output ports
  47  *      which are then pulled up with an external resistor. Setting this
  48  *      config will enable open drain mode, the argument is ignored.
  49  * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
  50  *      (open emitter). Setting this config will enable open source mode, the
  51  *      argument is ignored.
  52  * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
  53  *      low, this is the most typical case and is typically achieved with two
  54  *      active transistors on the output. Setting this config will enable
  55  *      push-pull mode, the argument is ignored.
  56  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
  57  *      passed as argument. The argument is in mA.
  58  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
  59  *      which means it will wait for signals to settle when reading inputs. The
  60  *      argument gives the debounce time in usecs. Setting the
  61  *      argument to zero turns debouncing off.
  62  * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
  63  *      affect the pin's ability to drive output.  1 enables input, 0 disables
  64  *      input.
  65  * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
  66  *      schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
  67  *      the threshold value is given on a custom format as argument when
  68  *      setting pins to this mode.
  69  * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
  70  *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
  71  *      schmitt-trigger mode is disabled.
  72  * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
  73  *      operation, if several modes of operation are supported these can be
  74  *      passed in the argument on a custom form, else just use argument 1
  75  *      to indicate low power mode, argument 0 turns low power mode off.
  76  * @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
  77  *      1 to indicate high level, argument 0 to indicate low level. (Please
  78  *      see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
  79  *      discussion around this parameter.)
  80  * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
  81  *      supplies, the argument to this parameter (on a custom format) tells
  82  *      the driver which alternative power source to use.
  83  * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
  84  *      this parameter (on a custom format) tells the driver which alternative
  85  *      slew rate to use.
  86  * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
  87  *      you need to pass in custom configurations to the pin controller, use
  88  *      PIN_CONFIG_END+1 as the base offset.
  89  * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
  90  *      presented using the packed format.
  91  */
  92 enum pin_config_param {
  93         PIN_CONFIG_BIAS_BUS_HOLD,
  94         PIN_CONFIG_BIAS_DISABLE,
  95         PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
  96         PIN_CONFIG_BIAS_PULL_DOWN,
  97         PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
  98         PIN_CONFIG_BIAS_PULL_UP,
  99         PIN_CONFIG_DRIVE_OPEN_DRAIN,
 100         PIN_CONFIG_DRIVE_OPEN_SOURCE,
 101         PIN_CONFIG_DRIVE_PUSH_PULL,
 102         PIN_CONFIG_DRIVE_STRENGTH,
 103         PIN_CONFIG_INPUT_DEBOUNCE,
 104         PIN_CONFIG_INPUT_ENABLE,
 105         PIN_CONFIG_INPUT_SCHMITT,
 106         PIN_CONFIG_INPUT_SCHMITT_ENABLE,
 107         PIN_CONFIG_LOW_POWER_MODE,
 108         PIN_CONFIG_OUTPUT,
 109         PIN_CONFIG_POWER_SOURCE,
 110         PIN_CONFIG_SLEW_RATE,
 111         PIN_CONFIG_END = 0x7F,
 112         PIN_CONFIG_MAX = 0xFF,
 113 };
 114
 115 /*
 116  * Helpful configuration macro to be used in tables etc.
 117  */
 118 #define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
 119
 120 /*
 121  * The following inlines stuffs a configuration parameter and data value
 122  * into and out of an unsigned long argument, as used by the generic pin config
 123  * system. We put the parameter in the lower 8 bits and the argument in the
 124  * upper 24 bits.
 125  */
 126
 127 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
 128 {
 129         return (enum pin_config_param) (config & 0xffUL);
 130 }
 131
 132 static inline u32 pinconf_to_config_argument(unsigned long config)
 133 {
 134         return (u32) ((config >> 8) & 0xffffffUL);
 135 }
 136
 137 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
 138                                                      u32 argument)
 139 {
 140         return PIN_CONF_PACKED(param, argument);
 141 }
 142
 143 #ifdef CONFIG_GENERIC_PINCONF
 144
 145 #ifdef CONFIG_DEBUG_FS
 146 #define PCONFDUMP(a, b, c, d) {                                 \
 147         .param = a, .display = b, .format = c, .has_arg = d     \
 148         }
 149
 150 struct pin_config_item {
 151         const enum pin_config_param param;
 152         const char * const display;
 153         const char * const format;
 154         bool has_arg;
 155 };
 156 #endif /* CONFIG_DEBUG_FS */
 157
 158 #ifdef CONFIG_OF
 159
 160 #include <linux/device.h>
 161 #include <linux/pinctrl/machine.h>
 162 struct pinctrl_dev;
 163 struct pinctrl_map;
 164
 165 struct pinconf_generic_params {
 166         const char * const property;
 167         enum pin_config_param param;
 168         u32 default_value;
 169 };
 170
 171 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
 172                 struct device_node *np, struct pinctrl_map **map,
 173                 unsigned *reserved_maps, unsigned *num_maps,
 174                 enum pinctrl_map_type type);
 175 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
 176                 struct device_node *np_config, struct pinctrl_map **map,
 177                 unsigned *num_maps, enum pinctrl_map_type type);
 178 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
 179                 struct pinctrl_map *map, unsigned num_maps);
 180
 181 static inline int pinconf_generic_dt_node_to_map_group(
 182                 struct pinctrl_dev *pctldev, struct device_node *np_config,
 183                 struct pinctrl_map **map, unsigned *num_maps)
 184 {
 185         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
 186                         PIN_MAP_TYPE_CONFIGS_GROUP);
 187 }
 188
 189 static inline int pinconf_generic_dt_node_to_map_pin(
 190                 struct pinctrl_dev *pctldev, struct device_node *np_config,
 191                 struct pinctrl_map **map, unsigned *num_maps)
 192 {
 193         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
 194                         PIN_MAP_TYPE_CONFIGS_PIN);
 195 }
 196
 197 static inline int pinconf_generic_dt_node_to_map_all(
 198                 struct pinctrl_dev *pctldev, struct device_node *np_config,
 199                 struct pinctrl_map **map, unsigned *num_maps)
 200 {
 201         /*
 202          * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
 203          * to infer the map type from the DT properties used.
 204          */
 205         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
 206                         PIN_MAP_TYPE_INVALID);
 207 }
 208 #endif
 209
 210 #endif /* CONFIG_GENERIC_PINCONF */
 211
 212 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */