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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_ENABLE: this will enable the pin's output mode
77 * without driving a value there. For most platforms this reduces to
78 * enable the output buffers and then let the pin controller current
79 * configuration (eg. the currently selected mux function) drive values on
80 * the line. Use argument 1 to enable output mode, argument 0 to disable
81 * it.
82 * @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a
83 * value on the line. Use argument 1 to indicate high level, argument 0 to
84 * indicate low level. (Please see Documentation/driver-api/pinctl.rst,
85 * section "GPIO mode pitfalls" for a discussion around this parameter.)
86 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
87 * supplies, the argument to this parameter (on a custom format) tells
88 * the driver which alternative power source to use.
89 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
90 * this parameter (on a custom format) tells the driver which alternative
91 * slew rate to use.
92 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
93 * you need to pass in custom configurations to the pin controller, use
94 * PIN_CONFIG_END+1 as the base offset.
95 * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
96 * presented using the packed format.
97 */
98enum pin_config_param {
99 PIN_CONFIG_BIAS_BUS_HOLD,
100 PIN_CONFIG_BIAS_DISABLE,
101 PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
102 PIN_CONFIG_BIAS_PULL_DOWN,
103 PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
104 PIN_CONFIG_BIAS_PULL_UP,
105 PIN_CONFIG_DRIVE_OPEN_DRAIN,
106 PIN_CONFIG_DRIVE_OPEN_SOURCE,
107 PIN_CONFIG_DRIVE_PUSH_PULL,
108 PIN_CONFIG_DRIVE_STRENGTH,
109 PIN_CONFIG_INPUT_DEBOUNCE,
110 PIN_CONFIG_INPUT_ENABLE,
111 PIN_CONFIG_INPUT_SCHMITT,
112 PIN_CONFIG_INPUT_SCHMITT_ENABLE,
113 PIN_CONFIG_LOW_POWER_MODE,
114 PIN_CONFIG_OUTPUT_ENABLE,
115 PIN_CONFIG_OUTPUT,
116 PIN_CONFIG_POWER_SOURCE,
117 PIN_CONFIG_SLEW_RATE,
118 PIN_CONFIG_END = 0x7F,
119 PIN_CONFIG_MAX = 0xFF,
120};
121
122/*
123 * Helpful configuration macro to be used in tables etc.
124 */
125#define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
126
127/*
128 * The following inlines stuffs a configuration parameter and data value
129 * into and out of an unsigned long argument, as used by the generic pin config
130 * system. We put the parameter in the lower 8 bits and the argument in the
131 * upper 24 bits.
132 */
133
134static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
135{
136 return (enum pin_config_param) (config & 0xffUL);
137}
138
139static inline u32 pinconf_to_config_argument(unsigned long config)
140{
141 return (u32) ((config >> 8) & 0xffffffUL);
142}
143
144static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
145 u32 argument)
146{
147 return PIN_CONF_PACKED(param, argument);
148}
149
150#ifdef CONFIG_GENERIC_PINCONF
151
152#ifdef CONFIG_DEBUG_FS
153#define PCONFDUMP(a, b, c, d) { \
154 .param = a, .display = b, .format = c, .has_arg = d \
155 }
156
157struct pin_config_item {
158 const enum pin_config_param param;
159 const char * const display;
160 const char * const format;
161 bool has_arg;
162};
163#endif /* CONFIG_DEBUG_FS */
164
165#ifdef CONFIG_OF
166
167#include <linux/device.h>
168#include <linux/pinctrl/machine.h>
169struct pinctrl_dev;
170struct pinctrl_map;
171
172struct pinconf_generic_params {
173 const char * const property;
174 enum pin_config_param param;
175 u32 default_value;
176};
177
178int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
179 struct device_node *np, struct pinctrl_map **map,
180 unsigned *reserved_maps, unsigned *num_maps,
181 enum pinctrl_map_type type);
182int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
183 struct device_node *np_config, struct pinctrl_map **map,
184 unsigned *num_maps, enum pinctrl_map_type type);
185void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
186 struct pinctrl_map *map, unsigned num_maps);
187
188static inline int pinconf_generic_dt_node_to_map_group(
189 struct pinctrl_dev *pctldev, struct device_node *np_config,
190 struct pinctrl_map **map, unsigned *num_maps)
191{
192 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
193 PIN_MAP_TYPE_CONFIGS_GROUP);
194}
195
196static inline int pinconf_generic_dt_node_to_map_pin(
197 struct pinctrl_dev *pctldev, struct device_node *np_config,
198 struct pinctrl_map **map, unsigned *num_maps)
199{
200 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
201 PIN_MAP_TYPE_CONFIGS_PIN);
202}
203
204static inline int pinconf_generic_dt_node_to_map_all(
205 struct pinctrl_dev *pctldev, struct device_node *np_config,
206 struct pinctrl_map **map, unsigned *num_maps)
207{
208 /*
209 * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
210 * to infer the map type from the DT properties used.
211 */
212 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
213 PIN_MAP_TYPE_INVALID);
214}
215#endif
216
217#endif /* CONFIG_GENERIC_PINCONF */
218
219#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */