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_DRIVE_STRENGTH: the pin will output the current passed as 50 * argument. The argument is in mA. 51 * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin. 52 * If the argument != 0, schmitt-trigger mode is enabled. If it's 0, 53 * schmitt-trigger mode is disabled. 54 * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in 55 * schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis, 56 * the threshold value is given on a custom format as argument when 57 * setting pins to this mode. 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 on a custom format. Setting the 61 * argument to zero turns debouncing off. 62 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power 63 * supplies, the argument to this parameter (on a custom format) tells 64 * the driver which alternative power source to use. 65 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to 66 * this parameter (on a custom format) tells the driver which alternative 67 * slew rate to use. 68 * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power 69 * operation, if several modes of operation are supported these can be 70 * passed in the argument on a custom form, else just use argument 1 71 * to indicate low power mode, argument 0 turns low power mode off. 72 * @PIN_CONFIG_OUTPUT: this will configure the pin in output, use argument 73 * 1 to indicate high level, argument 0 to indicate low level. 74 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if 75 * you need to pass in custom configurations to the pin controller, use 76 * PIN_CONFIG_END+1 as the base offset. 77 */ 78 enum pin_config_param { 79 PIN_CONFIG_BIAS_DISABLE, 80 PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 81 PIN_CONFIG_BIAS_PULL_UP, 82 PIN_CONFIG_BIAS_PULL_DOWN, 83 PIN_CONFIG_DRIVE_PUSH_PULL, 84 PIN_CONFIG_DRIVE_OPEN_DRAIN, 85 PIN_CONFIG_DRIVE_OPEN_SOURCE, 86 PIN_CONFIG_DRIVE_STRENGTH, 87 PIN_CONFIG_INPUT_SCHMITT_ENABLE, 88 PIN_CONFIG_INPUT_SCHMITT, 89 PIN_CONFIG_INPUT_DEBOUNCE, 90 PIN_CONFIG_POWER_SOURCE, 91 PIN_CONFIG_SLEW_RATE, 92 PIN_CONFIG_LOW_POWER_MODE, 93 PIN_CONFIG_OUTPUT, 94 PIN_CONFIG_END = 0x7FFF, 95 }; 96 97 /* 98 * Helpful configuration macro to be used in tables etc. 99 */ 100 #define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL)) 101 102 /* 103 * The following inlines stuffs a configuration parameter and data value 104 * into and out of an unsigned long argument, as used by the generic pin config 105 * system. We put the parameter in the lower 16 bits and the argument in the 106 * upper 16 bits. 107 */ 108 109 static inline enum pin_config_param pinconf_to_config_param(unsigned long config) 110 { 111 return (enum pin_config_param) (config & 0xffffUL); 112 } 113 114 static inline u16 pinconf_to_config_argument(unsigned long config) 115 { 116 return (enum pin_config_param) ((config >> 16) & 0xffffUL); 117 } 118 119 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param, 120 u16 argument) 121 { 122 return PIN_CONF_PACKED(param, argument); 123 } 124 125 #endif /* CONFIG_GENERIC_PINCONF */ 126 127 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */ 128