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_MODE_LOW_POWER: 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_MODE_PWM: this will configure the pin for PWM
84 * @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a
85 * value on the line. Use argument 1 to indicate high level, argument 0 to
86 * indicate low level. (Please see Documentation/driver-api/pin-control.rst,
87 * section "GPIO mode pitfalls" for a discussion around this parameter.)
88 * @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
89 * without driving a value there. For most platforms this reduces to
90 * enable the output buffers and then let the pin controller current
91 * configuration (eg. the currently selected mux function) drive values on
92 * the line. Use argument 1 to enable output mode, argument 0 to disable
93 * it.
94 * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset
95 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
96 * supplies, the argument to this parameter (on a custom format) tells
97 * the driver which alternative power source to use.
98 * @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
99 * or latch delay (on outputs) this parameter (in a custom format)
100 * specifies the clock skew or latch delay. It typically controls how
101 * many double inverters are put in front of the line.
102 * @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
103 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
104 * this parameter (on a custom format) tells the driver which alternative
105 * slew rate to use.
106 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
107 * you need to pass in custom configurations to the pin controller, use
108 * PIN_CONFIG_END+1 as the base offset.
109 * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
110 * presented using the packed format.
111 */
112 enum pin_config_param {
113 PIN_CONFIG_BIAS_BUS_HOLD,
114 PIN_CONFIG_BIAS_DISABLE,
115 PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
116 PIN_CONFIG_BIAS_PULL_DOWN,
117 PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
118 PIN_CONFIG_BIAS_PULL_UP,
119 PIN_CONFIG_DRIVE_OPEN_DRAIN,
120 PIN_CONFIG_DRIVE_OPEN_SOURCE,
121 PIN_CONFIG_DRIVE_PUSH_PULL,
122 PIN_CONFIG_DRIVE_STRENGTH,
123 PIN_CONFIG_DRIVE_STRENGTH_UA,
124 PIN_CONFIG_INPUT_DEBOUNCE,
125 PIN_CONFIG_INPUT_ENABLE,
126 PIN_CONFIG_INPUT_SCHMITT,
127 PIN_CONFIG_INPUT_SCHMITT_ENABLE,
128 PIN_CONFIG_MODE_LOW_POWER,
129 PIN_CONFIG_MODE_PWM,
130 PIN_CONFIG_OUTPUT,
131 PIN_CONFIG_OUTPUT_ENABLE,
132 PIN_CONFIG_PERSIST_STATE,
133 PIN_CONFIG_POWER_SOURCE,
134 PIN_CONFIG_SKEW_DELAY,
135 PIN_CONFIG_SLEEP_HARDWARE_STATE,
136 PIN_CONFIG_SLEW_RATE,
137 PIN_CONFIG_END = 0x7F,
138 PIN_CONFIG_MAX = 0xFF,
139 };
140
141 /*
142 * Helpful configuration macro to be used in tables etc.
143 */
144 #define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
145
146 /*
147 * The following inlines stuffs a configuration parameter and data value
148 * into and out of an unsigned long argument, as used by the generic pin config
149 * system. We put the parameter in the lower 8 bits and the argument in the
150 * upper 24 bits.
151 */
152
pinconf_to_config_param(unsigned long config)153 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
154 {
155 return (enum pin_config_param) (config & 0xffUL);
156 }
157
pinconf_to_config_argument(unsigned long config)158 static inline u32 pinconf_to_config_argument(unsigned long config)
159 {
160 return (u32) ((config >> 8) & 0xffffffUL);
161 }
162
pinconf_to_config_packed(enum pin_config_param param,u32 argument)163 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
164 u32 argument)
165 {
166 return PIN_CONF_PACKED(param, argument);
167 }
168
169 #define PCONFDUMP(a, b, c, d) { \
170 .param = a, .display = b, .format = c, .has_arg = d \
171 }
172
173 struct pin_config_item {
174 const enum pin_config_param param;
175 const char * const display;
176 const char * const format;
177 bool has_arg;
178 };
179
180 struct pinconf_generic_params {
181 const char * const property;
182 enum pin_config_param param;
183 u32 default_value;
184 };
185
186 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
187 struct device_node *np, struct pinctrl_map **map,
188 unsigned *reserved_maps, unsigned *num_maps,
189 enum pinctrl_map_type type);
190 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
191 struct device_node *np_config, struct pinctrl_map **map,
192 unsigned *num_maps, enum pinctrl_map_type type);
193 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
194 struct pinctrl_map *map, unsigned num_maps);
195
pinconf_generic_dt_node_to_map_group(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)196 static inline int pinconf_generic_dt_node_to_map_group(
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_GROUP);
202 }
203
pinconf_generic_dt_node_to_map_pin(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)204 static inline int pinconf_generic_dt_node_to_map_pin(
205 struct pinctrl_dev *pctldev, struct device_node *np_config,
206 struct pinctrl_map **map, unsigned *num_maps)
207 {
208 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
209 PIN_MAP_TYPE_CONFIGS_PIN);
210 }
211
pinconf_generic_dt_node_to_map_all(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)212 static inline int pinconf_generic_dt_node_to_map_all(
213 struct pinctrl_dev *pctldev, struct device_node *np_config,
214 struct pinctrl_map **map, unsigned *num_maps)
215 {
216 /*
217 * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
218 * to infer the map type from the DT properties used.
219 */
220 return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
221 PIN_MAP_TYPE_INVALID);
222 }
223
224 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */
225