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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 
pinconf_to_config_param(unsigned long config)151 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
152 {
153 	return (enum pin_config_param) (config & 0xffUL);
154 }
155 
pinconf_to_config_argument(unsigned long config)156 static inline u32 pinconf_to_config_argument(unsigned long config)
157 {
158 	return (u32) ((config >> 8) & 0xffffffUL);
159 }
160 
pinconf_to_config_packed(enum pin_config_param param,u32 argument)161 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
162 						     u32 argument)
163 {
164 	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 
pinconf_generic_dt_node_to_map_group(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)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 
pinconf_generic_dt_node_to_map_pin(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)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 
pinconf_generic_dt_node_to_map_all(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)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 	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 */
223