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       1                 :            : /* SPDX-License-Identifier: GPL-2.0-only */
       2                 :            : /*
       3                 :            :  * Interface the generic pinconfig portions of the pinctrl subsystem
       4                 :            :  *
       5                 :            :  * Copyright (C) 2011 ST-Ericsson SA
       6                 :            :  * Written on behalf of Linaro for ST-Ericsson
       7                 :            :  * This interface is used in the core to keep track of pins.
       8                 :            :  *
       9                 :            :  * Author: Linus Walleij <linus.walleij@linaro.org>
      10                 :            :  */
      11                 :            : #ifndef __LINUX_PINCTRL_PINCONF_GENERIC_H
      12                 :            : #define __LINUX_PINCTRL_PINCONF_GENERIC_H
      13                 :            : 
      14                 :            : #include <linux/device.h>
      15                 :            : #include <linux/pinctrl/machine.h>
      16                 :            : 
      17                 :            : struct pinctrl_dev;
      18                 :            : struct pinctrl_map;
      19                 :            : 
      20                 :            : /**
      21                 :            :  * enum pin_config_param - possible pin configuration parameters
      22                 :            :  * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
      23                 :            :  *      weakly drives the last value on a tristate bus, also known as a "bus
      24                 :            :  *      holder", "bus keeper" or "repeater". This allows another device on the
      25                 :            :  *      bus to change the value by driving the bus high or low and switching to
      26                 :            :  *      tristate. The argument is ignored.
      27                 :            :  * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
      28                 :            :  *      transition from say pull-up to pull-down implies that you disable
      29                 :            :  *      pull-up in the process, this setting disables all biasing.
      30                 :            :  * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
      31                 :            :  *      mode, also know as "third-state" (tristate) or "high-Z" or "floating".
      32                 :            :  *      On output pins this effectively disconnects the pin, which is useful
      33                 :            :  *      if for example some other pin is going to drive the signal connected
      34                 :            :  *      to it for a while. Pins used for input are usually always high
      35                 :            :  *      impedance.
      36                 :            :  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
      37                 :            :  *      impedance to GROUND). If the argument is != 0 pull-down is enabled,
      38                 :            :  *      if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
      39                 :            :  * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
      40                 :            :  *      on embedded knowledge of the controller hardware, like current mux
      41                 :            :  *      function. The pull direction and possibly strength too will normally
      42                 :            :  *      be decided completely inside the hardware block and not be readable
      43                 :            :  *      from the kernel side.
      44                 :            :  *      If the argument is != 0 pull up/down is enabled, if it is 0, the
      45                 :            :  *      configuration is ignored. The proper way to disable it is to use
      46                 :            :  *      @PIN_CONFIG_BIAS_DISABLE.
      47                 :            :  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
      48                 :            :  *      impedance to VDD). If the argument is != 0 pull-up is enabled,
      49                 :            :  *      if it is 0, pull-up is total, i.e. the pin is connected to VDD.
      50                 :            :  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
      51                 :            :  *      collector) which means it is usually wired with other output ports
      52                 :            :  *      which are then pulled up with an external resistor. Setting this
      53                 :            :  *      config will enable open drain mode, the argument is ignored.
      54                 :            :  * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
      55                 :            :  *      (open emitter). Setting this config will enable open source mode, the
      56                 :            :  *      argument is ignored.
      57                 :            :  * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
      58                 :            :  *      low, this is the most typical case and is typically achieved with two
      59                 :            :  *      active transistors on the output. Setting this config will enable
      60                 :            :  *      push-pull mode, the argument is ignored.
      61                 :            :  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
      62                 :            :  *      passed as argument. The argument is in mA.
      63                 :            :  * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
      64                 :            :  *      passed as argument. The argument is in uA.
      65                 :            :  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
      66                 :            :  *      which means it will wait for signals to settle when reading inputs. The
      67                 :            :  *      argument gives the debounce time in usecs. Setting the
      68                 :            :  *      argument to zero turns debouncing off.
      69                 :            :  * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
      70                 :            :  *      affect the pin's ability to drive output.  1 enables input, 0 disables
      71                 :            :  *      input.
      72                 :            :  * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
      73                 :            :  *      schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
      74                 :            :  *      the threshold value is given on a custom format as argument when
      75                 :            :  *      setting pins to this mode.
      76                 :            :  * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
      77                 :            :  *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
      78                 :            :  *      schmitt-trigger mode is disabled.
      79                 :            :  * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
      80                 :            :  *      operation, if several modes of operation are supported these can be
      81                 :            :  *      passed in the argument on a custom form, else just use argument 1
      82                 :            :  *      to indicate low power mode, argument 0 turns low power mode off.
      83                 :            :  * @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
      84                 :            :  *      without driving a value there. For most platforms this reduces to
      85                 :            :  *      enable the output buffers and then let the pin controller current
      86                 :            :  *      configuration (eg. the currently selected mux function) drive values on
      87                 :            :  *      the line. Use argument 1 to enable output mode, argument 0 to disable
      88                 :            :  *      it.
      89                 :            :  * @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a
      90                 :            :  *      value on the line. Use argument 1 to indicate high level, argument 0 to
      91                 :            :  *      indicate low level. (Please see Documentation/driver-api/pinctl.rst,
      92                 :            :  *      section "GPIO mode pitfalls" for a discussion around this parameter.)
      93                 :            :  * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
      94                 :            :  *      supplies, the argument to this parameter (on a custom format) tells
      95                 :            :  *      the driver which alternative power source to use.
      96                 :            :  * @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
      97                 :            :  * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
      98                 :            :  *      this parameter (on a custom format) tells the driver which alternative
      99                 :            :  *      slew rate to use.
     100                 :            :  * @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
     101                 :            :  *      or latch delay (on outputs) this parameter (in a custom format)
     102                 :            :  *      specifies the clock skew or latch delay. It typically controls how
     103                 :            :  *      many double inverters are put in front of the line.
     104                 :            :  * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset
     105                 :            :  * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
     106                 :            :  *      you need to pass in custom configurations to the pin controller, use
     107                 :            :  *      PIN_CONFIG_END+1 as the base offset.
     108                 :            :  * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
     109                 :            :  *      presented using the packed format.
     110                 :            :  */
     111                 :            : enum pin_config_param {
     112                 :            :         PIN_CONFIG_BIAS_BUS_HOLD,
     113                 :            :         PIN_CONFIG_BIAS_DISABLE,
     114                 :            :         PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
     115                 :            :         PIN_CONFIG_BIAS_PULL_DOWN,
     116                 :            :         PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
     117                 :            :         PIN_CONFIG_BIAS_PULL_UP,
     118                 :            :         PIN_CONFIG_DRIVE_OPEN_DRAIN,
     119                 :            :         PIN_CONFIG_DRIVE_OPEN_SOURCE,
     120                 :            :         PIN_CONFIG_DRIVE_PUSH_PULL,
     121                 :            :         PIN_CONFIG_DRIVE_STRENGTH,
     122                 :            :         PIN_CONFIG_DRIVE_STRENGTH_UA,
     123                 :            :         PIN_CONFIG_INPUT_DEBOUNCE,
     124                 :            :         PIN_CONFIG_INPUT_ENABLE,
     125                 :            :         PIN_CONFIG_INPUT_SCHMITT,
     126                 :            :         PIN_CONFIG_INPUT_SCHMITT_ENABLE,
     127                 :            :         PIN_CONFIG_LOW_POWER_MODE,
     128                 :            :         PIN_CONFIG_OUTPUT_ENABLE,
     129                 :            :         PIN_CONFIG_OUTPUT,
     130                 :            :         PIN_CONFIG_POWER_SOURCE,
     131                 :            :         PIN_CONFIG_SLEEP_HARDWARE_STATE,
     132                 :            :         PIN_CONFIG_SLEW_RATE,
     133                 :            :         PIN_CONFIG_SKEW_DELAY,
     134                 :            :         PIN_CONFIG_PERSIST_STATE,
     135                 :            :         PIN_CONFIG_END = 0x7F,
     136                 :            :         PIN_CONFIG_MAX = 0xFF,
     137                 :            : };
     138                 :            : 
     139                 :            : /*
     140                 :            :  * Helpful configuration macro to be used in tables etc.
     141                 :            :  */
     142                 :            : #define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
     143                 :            : 
     144                 :            : /*
     145                 :            :  * The following inlines stuffs a configuration parameter and data value
     146                 :            :  * into and out of an unsigned long argument, as used by the generic pin config
     147                 :            :  * system. We put the parameter in the lower 8 bits and the argument in the
     148                 :            :  * upper 24 bits.
     149                 :            :  */
     150                 :            : 
     151                 :            : static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
     152                 :            : {
     153                 :          3 :         return (enum pin_config_param) (config & 0xffUL);
     154                 :            : }
     155                 :            : 
     156                 :            : static inline u32 pinconf_to_config_argument(unsigned long config)
     157                 :            : {
     158                 :          3 :         return (u32) ((config >> 8) & 0xffffffUL);
     159                 :            : }
     160                 :            : 
     161                 :            : static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
     162                 :            :                                                      u32 argument)
     163                 :            : {
     164                 :          3 :         return PIN_CONF_PACKED(param, argument);
     165                 :            : }
     166                 :            : 
     167                 :            : #define PCONFDUMP(a, b, c, d) {                                 \
     168                 :            :         .param = a, .display = b, .format = c, .has_arg = d     \
     169                 :            :         }
     170                 :            : 
     171                 :            : struct pin_config_item {
     172                 :            :         const enum pin_config_param param;
     173                 :            :         const char * const display;
     174                 :            :         const char * const format;
     175                 :            :         bool has_arg;
     176                 :            : };
     177                 :            : 
     178                 :            : struct pinconf_generic_params {
     179                 :            :         const char * const property;
     180                 :            :         enum pin_config_param param;
     181                 :            :         u32 default_value;
     182                 :            : };
     183                 :            : 
     184                 :            : int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
     185                 :            :                 struct device_node *np, struct pinctrl_map **map,
     186                 :            :                 unsigned *reserved_maps, unsigned *num_maps,
     187                 :            :                 enum pinctrl_map_type type);
     188                 :            : int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
     189                 :            :                 struct device_node *np_config, struct pinctrl_map **map,
     190                 :            :                 unsigned *num_maps, enum pinctrl_map_type type);
     191                 :            : void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
     192                 :            :                 struct pinctrl_map *map, unsigned num_maps);
     193                 :            : 
     194                 :            : static inline int pinconf_generic_dt_node_to_map_group(
     195                 :            :                 struct pinctrl_dev *pctldev, struct device_node *np_config,
     196                 :            :                 struct pinctrl_map **map, unsigned *num_maps)
     197                 :            : {
     198                 :            :         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
     199                 :            :                         PIN_MAP_TYPE_CONFIGS_GROUP);
     200                 :            : }
     201                 :            : 
     202                 :            : static inline int pinconf_generic_dt_node_to_map_pin(
     203                 :            :                 struct pinctrl_dev *pctldev, struct device_node *np_config,
     204                 :            :                 struct pinctrl_map **map, unsigned *num_maps)
     205                 :            : {
     206                 :            :         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
     207                 :            :                         PIN_MAP_TYPE_CONFIGS_PIN);
     208                 :            : }
     209                 :            : 
     210                 :            : static inline int pinconf_generic_dt_node_to_map_all(
     211                 :            :                 struct pinctrl_dev *pctldev, struct device_node *np_config,
     212                 :            :                 struct pinctrl_map **map, unsigned *num_maps)
     213                 :            : {
     214                 :            :         /*
     215                 :            :          * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
     216                 :            :          * to infer the map type from the DT properties used.
     217                 :            :          */
     218                 :          3 :         return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
     219                 :            :                         PIN_MAP_TYPE_INVALID);
     220                 :            : }
     221                 :            : 
     222                 :            : #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */