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