1 /*
2  * Interface the generic pinconfig portions of the pinctrl subsystem
3  *
4  * Copyright (C) 2011 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  * This interface is used in the core to keep track of pins.
7  *
8  * Author: Linus Walleij <linus.walleij@linaro.org>
9  *
10  * License terms: GNU General Public License (GPL) version 2
11  */
12 #ifndef __LINUX_PINCTRL_PINCONF_GENERIC_H
13 #define __LINUX_PINCTRL_PINCONF_GENERIC_H
14 
15 /*
16  * You shouldn't even be able to compile with these enums etc unless you're
17  * using generic pin config. That is why this is defined out.
18  */
19 #ifdef CONFIG_GENERIC_PINCONF
20 
21 /**
22  * enum pin_config_param - possible pin configuration parameters
23  * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
24  *	weakly drives the last value on a tristate bus, also known as a "bus
25  *	holder", "bus keeper" or "repeater". This allows another device on the
26  *	bus to change the value by driving the bus high or low and switching to
27  *	tristate. The argument is ignored.
28  * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
29  *	transition from say pull-up to pull-down implies that you disable
30  *	pull-up in the process, this setting disables all biasing.
31  * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
32  *	mode, also know as "third-state" (tristate) or "high-Z" or "floating".
33  *	On output pins this effectively disconnects the pin, which is useful
34  *	if for example some other pin is going to drive the signal connected
35  *	to it for a while. Pins used for input are usually always high
36  *	impedance.
37  * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
38  *	impedance to GROUND). If the argument is != 0 pull-down is enabled,
39  *	if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
40  * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
41  *	on embedded knowledge of the controller hardware, like current mux
42  *	function. The pull direction and possibly strength too will normally
43  *	be decided completely inside the hardware block and not be readable
44  *	from the kernel side.
45  *	If the argument is != 0 pull up/down is enabled, if it is 0, the
46  *	configuration is ignored. The proper way to disable it is to use
47  *	@PIN_CONFIG_BIAS_DISABLE.
48  * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
49  *	impedance to VDD). If the argument is != 0 pull-up is enabled,
50  *	if it is 0, pull-up is total, i.e. the pin is connected to VDD.
51  * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
52  *	collector) which means it is usually wired with other output ports
53  *	which are then pulled up with an external resistor. Setting this
54  *	config will enable open drain mode, the argument is ignored.
55  * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
56  *	(open emitter). Setting this config will enable open source mode, the
57  *	argument is ignored.
58  * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
59  *	low, this is the most typical case and is typically achieved with two
60  *	active transistors on the output. Setting this config will enable
61  *	push-pull mode, the argument is ignored.
62  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
63  *	passed as argument. The argument is in mA.
64  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
65  *	which means it will wait for signals to settle when reading inputs. The
66  *	argument gives the debounce time in usecs. Setting the
67  *	argument to zero turns debouncing off.
68  * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
69  *	affect the pin's ability to drive output.  1 enables input, 0 disables
70  *	input.
71  * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
72  *	schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
73  *	the threshold value is given on a custom format as argument when
74  *	setting pins to this mode.
75  * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
76  *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
77  *      schmitt-trigger mode is disabled.
78  * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
79  *	operation, if several modes of operation are supported these can be
80  *	passed in the argument on a custom form, else just use argument 1
81  *	to indicate low power mode, argument 0 turns low power mode off.
82  * @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
83  *	1 to indicate high level, argument 0 to indicate low level. (Please
84  *	see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
85  *	discussion around this parameter.)
86  * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
87  *	supplies, the argument to this parameter (on a custom format) tells
88  *	the driver which alternative power source to use.
89  * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
90  *	this parameter (on a custom format) tells the driver which alternative
91  *	slew rate to use.
92  * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
93  *	you need to pass in custom configurations to the pin controller, use
94  *	PIN_CONFIG_END+1 as the base offset.
95  */
96 enum pin_config_param {
97 	PIN_CONFIG_BIAS_BUS_HOLD,
98 	PIN_CONFIG_BIAS_DISABLE,
99 	PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
100 	PIN_CONFIG_BIAS_PULL_DOWN,
101 	PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
102 	PIN_CONFIG_BIAS_PULL_UP,
103 	PIN_CONFIG_DRIVE_OPEN_DRAIN,
104 	PIN_CONFIG_DRIVE_OPEN_SOURCE,
105 	PIN_CONFIG_DRIVE_PUSH_PULL,
106 	PIN_CONFIG_DRIVE_STRENGTH,
107 	PIN_CONFIG_INPUT_DEBOUNCE,
108 	PIN_CONFIG_INPUT_ENABLE,
109 	PIN_CONFIG_INPUT_SCHMITT,
110 	PIN_CONFIG_INPUT_SCHMITT_ENABLE,
111 	PIN_CONFIG_LOW_POWER_MODE,
112 	PIN_CONFIG_OUTPUT,
113 	PIN_CONFIG_POWER_SOURCE,
114 	PIN_CONFIG_SLEW_RATE,
115 	PIN_CONFIG_END = 0x7FFF,
116 };
117 
118 #ifdef CONFIG_DEBUG_FS
119 #define PCONFDUMP(a, b, c, d) { .param = a, .display = b, .format = c, \
120 				.has_arg = d }
121 
122 struct pin_config_item {
123 	const enum pin_config_param param;
124 	const char * const display;
125 	const char * const format;
126 	bool has_arg;
127 };
128 #endif /* CONFIG_DEBUG_FS */
129 
130 /*
131  * Helpful configuration macro to be used in tables etc.
132  */
133 #define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL))
134 
135 /*
136  * The following inlines stuffs a configuration parameter and data value
137  * into and out of an unsigned long argument, as used by the generic pin config
138  * system. We put the parameter in the lower 16 bits and the argument in the
139  * upper 16 bits.
140  */
141 
pinconf_to_config_param(unsigned long config)142 static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
143 {
144 	return (enum pin_config_param) (config & 0xffffUL);
145 }
146 
pinconf_to_config_argument(unsigned long config)147 static inline u16 pinconf_to_config_argument(unsigned long config)
148 {
149 	return (enum pin_config_param) ((config >> 16) & 0xffffUL);
150 }
151 
pinconf_to_config_packed(enum pin_config_param param,u16 argument)152 static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
153 						     u16 argument)
154 {
155 	return PIN_CONF_PACKED(param, argument);
156 }
157 
158 #ifdef CONFIG_OF
159 
160 #include <linux/device.h>
161 #include <linux/pinctrl/machine.h>
162 struct pinctrl_dev;
163 struct pinctrl_map;
164 
165 struct pinconf_generic_params {
166 	const char * const property;
167 	enum pin_config_param param;
168 	u32 default_value;
169 };
170 
171 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
172 		struct device_node *np, struct pinctrl_map **map,
173 		unsigned *reserved_maps, unsigned *num_maps,
174 		enum pinctrl_map_type type);
175 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
176 		struct device_node *np_config, struct pinctrl_map **map,
177 		unsigned *num_maps, enum pinctrl_map_type type);
178 
pinconf_generic_dt_node_to_map_group(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)179 static inline int pinconf_generic_dt_node_to_map_group(
180 		struct pinctrl_dev *pctldev, struct device_node *np_config,
181 		struct pinctrl_map **map, unsigned *num_maps)
182 {
183 	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
184 			PIN_MAP_TYPE_CONFIGS_GROUP);
185 }
186 
pinconf_generic_dt_node_to_map_pin(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)187 static inline int pinconf_generic_dt_node_to_map_pin(
188 		struct pinctrl_dev *pctldev, struct device_node *np_config,
189 		struct pinctrl_map **map, unsigned *num_maps)
190 {
191 	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
192 			PIN_MAP_TYPE_CONFIGS_PIN);
193 }
194 
pinconf_generic_dt_node_to_map_all(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned * num_maps)195 static inline int pinconf_generic_dt_node_to_map_all(
196 		struct pinctrl_dev *pctldev, struct device_node *np_config,
197 		struct pinctrl_map **map, unsigned *num_maps)
198 {
199 	/*
200 	 * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
201 	 * to infer the map type from the DT properties used.
202 	 */
203 	return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
204 			PIN_MAP_TYPE_INVALID);
205 }
206 #endif
207 
208 #endif /* CONFIG_GENERIC_PINCONF */
209 
210 #endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */
211