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 <[email protected]> 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_DISABLE: disable schmitt-trigger mode on the pin. 50 * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in 51 * schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis, 52 * the threshold value is given on a custom format as argument when 53 * setting pins to this mode. 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_DISABLE, 78 PIN_CONFIG_INPUT_SCHMITT, 79 PIN_CONFIG_INPUT_DEBOUNCE, 80 PIN_CONFIG_POWER_SOURCE, 81 PIN_CONFIG_LOW_POWER_MODE, 82 PIN_CONFIG_END = 0x7FFF, 83 }; 84 85 /* 86 * Helpful configuration macro to be used in tables etc. 87 */ 88 #define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL)) 89 90 /* 91 * The following inlines stuffs a configuration parameter and data value 92 * into and out of an unsigned long argument, as used by the generic pin config 93 * system. We put the parameter in the lower 16 bits and the argument in the 94 * upper 16 bits. 95 */ 96 97 static inline enum pin_config_param pinconf_to_config_param(unsigned long config) 98 { 99 return (enum pin_config_param) (config & 0xffffUL); 100 } 101 102 static inline u16 pinconf_to_config_argument(unsigned long config) 103 { 104 return (enum pin_config_param) ((config >> 16) & 0xffffUL); 105 } 106 107 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param, 108 u16 argument) 109 { 110 return PIN_CONF_PACKED(param, argument); 111 } 112 113 #endif /* CONFIG_GENERIC_PINCONF */ 114 115 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */ 116