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/types.h>
15
16 #include <linux/pinctrl/machine.h>
17
18 struct device_node;
19
20 struct pinctrl_dev;
21 struct pinctrl_map;
22
23 /**
24 * enum pin_config_param - possible pin configuration parameters
25 * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
26 * weakly drives the last value on a tristate bus, also known as a "bus
27 * holder", "bus keeper" or "repeater". This allows another device on the
28 * bus to change the value by driving the bus high or low and switching to
29 * tristate. The argument is ignored.
30 * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
31 * transition from say pull-up to pull-down implies that you disable
32 * pull-up in the process, this setting disables all biasing.
33 * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
34 * mode, also know as "third-state" (tristate) or "high-Z" or "floating".
35 * On output pins this effectively disconnects the pin, which is useful
36 * if for example some other pin is going to drive the signal connected
37 * to it for a while. Pins used for input are usually always high
38 * impedance.
39 * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
40 * impedance to GROUND). If the argument is != 0 pull-down is enabled,
41 * the value is interpreted by the driver and can be custom or an SI unit
42 * such as Ohms.
43 * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
44 * on embedded knowledge of the controller hardware, like current mux
45 * function. The pull direction and possibly strength too will normally
46 * be decided completely inside the hardware block and not be readable
47 * from the kernel side.
48 * If the argument is != 0 pull up/down is enabled, if it is 0, the
49 * configuration is ignored. The proper way to disable it is to use
50 * @PIN_CONFIG_BIAS_DISABLE.
51 * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
52 * impedance to VDD). If the argument is != 0 pull-up is enabled,
53 * the value is interpreted by the driver and can be custom or an SI unit
54 * such as Ohms.
55 * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
56 * collector) which means it is usually wired with other output ports
57 * which are then pulled up with an external resistor. Setting this
58 * config will enable open drain mode, the argument is ignored.
59 * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
60 * (open emitter). Setting this config will enable open source mode, the
61 * argument is ignored.
62 * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
63 * low, this is the most typical case and is typically achieved with two
64 * active transistors on the output. Setting this config will enable
65 * push-pull mode, the argument is ignored.
66 * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
67 * passed as argument. The argument is in mA.
68 * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
69 * passed as argument. The argument is in uA.
70 * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
71 * which means it will wait for signals to settle when reading inputs. The
72 * argument gives the debounce time in usecs. Setting the
73 * argument to zero turns debouncing off.
74 * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input. Note that this does not
75 * affect the pin's ability to drive output. 1 enables input, 0 disables
76 * input.
77 * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
78 * schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
79 * the threshold value is given on a custom format as argument when
80 * setting pins to this mode.
81 * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
82 * If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
83 * schmitt-trigger mode is disabled.
84 * @PIN_CONFIG_MODE_LOW_POWER: this will configure the pin for low power
85 * operation, if several modes of operation are supported these can be
86 * passed in the argument on a custom form, else just use argument 1
87 * to indicate low power mode, argument 0 turns low power mode off.
88 * @PIN_CONFIG_MODE_PWM: this will configure the pin for PWM
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/pin-control.rst,
92 * section "GPIO mode pitfalls" for a discussion around this parameter.)
93 * @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
94 * without driving a value there. For most platforms this reduces to
95 * enable the output buffers and then let the pin controller current
96 * configuration (eg. the currently selected mux function) drive values on
97 * the line. Use argument 1 to enable output mode, argument 0 to disable
98 * it.
99 * @PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS: this will configure the output impedance
100 * of the pin with the value passed as argument. The argument is in ohms.
101 * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset
102 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
103 * supplies, the argument to this parameter (on a custom format) tells
104 * the driver which alternative power source to use.
105 * @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
106 * or latch delay (on outputs) this parameter (in a custom format)
107 * specifies the clock skew or latch delay. It typically controls how
108 * many double inverters are put in front of the line.
109 * @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
110 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
111 * this parameter (on a custom format) tells the driver which alternative
112 * slew rate to use.
113 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
114 * you need to pass in custom configurations to the pin controller, use
115 * PIN_CONFIG_END+1 as the base offset.
116 * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
117 * presented using the packed format.
118 */
119 enum pin_config_param {
120 PIN_CONFIG_BIAS_BUS_HOLD,
121 PIN_CONFIG_BIAS_DISABLE,
122 PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
123 PIN_CONFIG_BIAS_PULL_DOWN,
124 PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
125 PIN_CONFIG_BIAS_PULL_UP,
126 PIN_CONFIG_DRIVE_OPEN_DRAIN,
127 PIN_CONFIG_DRIVE_OPEN_SOURCE,
128 PIN_CONFIG_DRIVE_PUSH_PULL,
129 PIN_CONFIG_DRIVE_STRENGTH,
130 PIN_CONFIG_DRIVE_STRENGTH_UA,
131 PIN_CONFIG_INPUT_DEBOUNCE,
132 PIN_CONFIG_INPUT_ENABLE,
133 PIN_CONFIG_INPUT_SCHMITT,
134 PIN_CONFIG_INPUT_SCHMITT_ENABLE,
135 PIN_CONFIG_MODE_LOW_POWER,
136 PIN_CONFIG_MODE_PWM,
137 PIN_CONFIG_OUTPUT,
138 PIN_CONFIG_OUTPUT_ENABLE,
139 PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS,
140 PIN_CONFIG_PERSIST_STATE,
141 PIN_CONFIG_POWER_SOURCE,
142 PIN_CONFIG_SKEW_DELAY,
143 PIN_CONFIG_SLEEP_HARDWARE_STATE,
144 PIN_CONFIG_SLEW_RATE,
145 PIN_CONFIG_END = 0x7F,
146 PIN_CONFIG_MAX = 0xFF,
147 };
148
149 /*
150 * Helpful configuration macro to be used in tables etc.
151 */
152 #define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
153
154 /*
155 * The following inlines stuffs a configuration parameter and data value
156 * into and out of an unsigned long argument, as used by the generic pin config
157 * system. We put the parameter in the lower 8 bits and the argument in the
158 * upper 24 bits.
159 */
160
161 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
162 {
163 return (enum pin_config_param) (config & 0xffUL);
164 }
165
166 static inline u32 pinconf_to_config_argument(unsigned long config)
167 {
168 return (u32) ((config >> 8) & 0xffffffUL);
169 }
170
171 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
172 u32 argument)
173 {
174 return PIN_CONF_PACKED(param, argument);
175 }
176
177 #define PCONFDUMP(a, b, c, d) { \
178 .param = a, .display = b, .format = c, .has_arg = d \
179 }
180
181 struct pin_config_item {
182 const enum pin_config_param param;
183 const char * const display;
184 const char * const format;
185 bool has_arg;
186 };
187
188 struct pinconf_generic_params {
189 const char * const property;
190 enum pin_config_param param;
191 u32 default_value;
192 };
193
194 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
195 struct device_node *np, struct pinctrl_map **map,
196 unsigned int *reserved_maps, unsigned int *num_maps,
197 enum pinctrl_map_type type);
198 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
199 struct device_node *np_config, struct pinctrl_map **map,
200 unsigned int *num_maps, enum pinctrl_map_type type);
201 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
202 struct pinctrl_map *map, unsigned int num_maps);
203
204 static inline int pinconf_generic_dt_node_to_map_group(struct pinctrl_dev *pctldev,
205 struct device_node *np_config, struct pinctrl_map **map,
206 unsigned int *num_maps)
207 {
208 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
209 PIN_MAP_TYPE_CONFIGS_GROUP);
210 }
211
212 static inline int pinconf_generic_dt_node_to_map_pin(struct pinctrl_dev *pctldev,
213 struct device_node *np_config, struct pinctrl_map **map,
214 unsigned int *num_maps)
215 {
216 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
217 PIN_MAP_TYPE_CONFIGS_PIN);
218 }
219
220 static inline int pinconf_generic_dt_node_to_map_all(struct pinctrl_dev *pctldev,
221 struct device_node *np_config, struct pinctrl_map **map,
222 unsigned *num_maps)
223 {
224 /*
225 * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
226 * to infer the map type from the DT properties used.
227 */
228 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
229 PIN_MAP_TYPE_INVALID);
230 }
231
232 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */
233
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