pinconf-generic.h

  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
 18struct device_node;
 19
 20struct pinctrl_dev;
 21struct 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_INPUT_SCHMITT_UV: this will configure an input pin to run in
 85 *	schmitt-trigger mode. The argument is in uV.
 86 * @PIN_CONFIG_MODE_LOW_POWER: this will configure the pin for low power
 87 *	operation, if several modes of operation are supported these can be
 88 *	passed in the argument on a custom form, else just use argument 1
 89 *	to indicate low power mode, argument 0 turns low power mode off.
 90 * @PIN_CONFIG_MODE_PWM: this will configure the pin for PWM
 91 * @PIN_CONFIG_LEVEL: setting this will configure the pin as an output and
 92 *	drive a value on the line. Use argument 1 to indicate high level,
 93 *	argument 0 to indicate low level. Conversely the value of the line
 94 *	can be read using this parameter, if and only if that value can be
 95 *	represented as a binary 0 or 1 where 0 indicate a low voltage level
 96 *	and 1 indicate a high voltage level.
 97 *	(Please see Documentation/driver-api/pin-control.rst,
 98 *	section "GPIO mode pitfalls" for a discussion around this parameter.)
 99 * @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
100 * 	without driving a value there. For most platforms this reduces to
101 * 	enable the output buffers and then let the pin controller current
102 * 	configuration (eg. the currently selected mux function) drive values on
103 * 	the line. Use argument 1 to enable output mode, argument 0 to disable
104 * 	it.
105 * @PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS: this will configure the output impedance
106 * 	of the pin with the value passed as argument. The argument is in ohms.
107 * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset
108 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
109 *	supplies, the argument to this parameter (on a custom format) tells
110 *	the driver which alternative power source to use.
111 * @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
112 *	or latch delay (on outputs) this parameter (in a custom format)
113 *	specifies the clock skew or latch delay. It typically controls how
114 *	many double inverters are put in front of the line.
115 * @PIN_CONFIG_SKEW_DELAY_INPUT_PS: if the pin has independent values for the
116 *	programmable skew rate (on inputs) and latch delay (on outputs), then
117 *	this parameter specifies the clock skew only. The argument is in ps.
118 * @PIN_CONFIG_SKEW_DELAY_OUPUT_PS: if the pin has independent values for the
119 *	programmable skew rate (on inputs) and latch delay (on outputs), then
120 *	this parameter specifies the latch delay only. The argument is in ps.
121 * @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
122 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
123 *	this parameter (on a custom format) tells the driver which alternative
124 *	slew rate to use.
125 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
126 *	you need to pass in custom configurations to the pin controller, use
127 *	PIN_CONFIG_END+1 as the base offset.
128 * @PIN_CONFIG_MAX: this is the maximum configuration value that can be
129 *	presented using the packed format.
130 */
131enum pin_config_param {
132	PIN_CONFIG_BIAS_BUS_HOLD,
133	PIN_CONFIG_BIAS_DISABLE,
134	PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
135	PIN_CONFIG_BIAS_PULL_DOWN,
136	PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
137	PIN_CONFIG_BIAS_PULL_UP,
138	PIN_CONFIG_DRIVE_OPEN_DRAIN,
139	PIN_CONFIG_DRIVE_OPEN_SOURCE,
140	PIN_CONFIG_DRIVE_PUSH_PULL,
141	PIN_CONFIG_DRIVE_STRENGTH,
142	PIN_CONFIG_DRIVE_STRENGTH_UA,
143	PIN_CONFIG_INPUT_DEBOUNCE,
144	PIN_CONFIG_INPUT_ENABLE,
145	PIN_CONFIG_INPUT_SCHMITT,
146	PIN_CONFIG_INPUT_SCHMITT_ENABLE,
147	PIN_CONFIG_INPUT_SCHMITT_UV,
148	PIN_CONFIG_MODE_LOW_POWER,
149	PIN_CONFIG_MODE_PWM,
150	PIN_CONFIG_LEVEL,
151	PIN_CONFIG_OUTPUT_ENABLE,
152	PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS,
153	PIN_CONFIG_PERSIST_STATE,
154	PIN_CONFIG_POWER_SOURCE,
155	PIN_CONFIG_SKEW_DELAY,
156	PIN_CONFIG_SKEW_DELAY_INPUT_PS,
157	PIN_CONFIG_SKEW_DELAY_OUTPUT_PS,
158	PIN_CONFIG_SLEEP_HARDWARE_STATE,
159	PIN_CONFIG_SLEW_RATE,
160	PIN_CONFIG_END = 0x7F,
161	PIN_CONFIG_MAX = 0xFF,
162};
163
164/*
165 * Helpful configuration macro to be used in tables etc.
166 */
167#define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
168
169/*
170 * The following inlines stuffs a configuration parameter and data value
171 * into and out of an unsigned long argument, as used by the generic pin config
172 * system. We put the parameter in the lower 8 bits and the argument in the
173 * upper 24 bits.
174 */
175
176static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
177{
178	return (enum pin_config_param) (config & 0xffUL);
179}
180
181static inline u32 pinconf_to_config_argument(unsigned long config)
182{
183	return (u32) ((config >> 8) & 0xffffffUL);
184}
185
186static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
187						     u32 argument)
188{
189	return PIN_CONF_PACKED(param, argument);
190}
191
192#define PCONFDUMP_WITH_VALUES(a, b, c, d, e, f) {		\
193	.param = a, .display = b, .format = c, .has_arg = d,	\
194	.values = e, .num_values = f				\
195	}
196
197#define PCONFDUMP(a, b, c, d)	PCONFDUMP_WITH_VALUES(a, b, c, d, NULL, 0)
198
199struct pin_config_item {
200	const enum pin_config_param param;
201	const char * const display;
202	const char * const format;
203	bool has_arg;
204	const char * const *values;
205	size_t num_values;
206};
207
208struct pinconf_generic_params {
209	const char * const property;
210	enum pin_config_param param;
211	u32 default_value;
212	const char * const *values;
213	size_t num_values;
214};
215
216int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
217		struct device_node *np, struct pinctrl_map **map,
218		unsigned int *reserved_maps, unsigned int *num_maps,
219		enum pinctrl_map_type type);
220int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
221		struct device_node *np_config, struct pinctrl_map **map,
222		unsigned int *num_maps, enum pinctrl_map_type type);
223void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
224		struct pinctrl_map *map, unsigned int num_maps);
225
226static inline int pinconf_generic_dt_node_to_map_group(struct pinctrl_dev *pctldev,
227		struct device_node *np_config, struct pinctrl_map **map,
228		unsigned int *num_maps)
229{
230	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
231			PIN_MAP_TYPE_CONFIGS_GROUP);
232}
233
234static inline int pinconf_generic_dt_node_to_map_pin(struct pinctrl_dev *pctldev,
235		struct device_node *np_config, struct pinctrl_map **map,
236		unsigned int *num_maps)
237{
238	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
239			PIN_MAP_TYPE_CONFIGS_PIN);
240}
241
242static inline int pinconf_generic_dt_node_to_map_all(struct pinctrl_dev *pctldev,
243		struct device_node *np_config, struct pinctrl_map **map,
244		unsigned *num_maps)
245{
246	/*
247	 * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
248	 * to infer the map type from the DT properties used.
249	 */
250	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
251			PIN_MAP_TYPE_INVALID);
252}
253#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */