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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 : 828 : return (enum pin_config_param) (config & 0xffUL);
154 : : }
155 : :
156 : : static inline u32 pinconf_to_config_argument(unsigned long config)
157 : : {
158 : 828 : 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 : 414 : 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 : 621 : 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 */
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