xref: /openbmc/linux/drivers/gpio/gpiolib.h (revision 827634ad)
1 /*
2  * Internal GPIO functions.
3  *
4  * Copyright (C) 2013, Intel Corporation
5  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #ifndef GPIOLIB_H
13 #define GPIOLIB_H
14 
15 #include <linux/err.h>
16 #include <linux/device.h>
17 
18 enum of_gpio_flags;
19 
20 struct acpi_device;
21 
22 /**
23  * struct acpi_gpio_info - ACPI GPIO specific information
24  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
25  * @active_low: in case of @gpioint, the pin is active low
26  */
27 struct acpi_gpio_info {
28 	bool gpioint;
29 	bool active_low;
30 };
31 
32 /* gpio suffixes used for ACPI and device tree lookup */
33 static const char * const gpio_suffixes[] = { "gpios", "gpio" };
34 
35 #ifdef CONFIG_ACPI
36 void acpi_gpiochip_add(struct gpio_chip *chip);
37 void acpi_gpiochip_remove(struct gpio_chip *chip);
38 
39 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
40 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
41 
42 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
43 					  const char *propname, int index,
44 					  struct acpi_gpio_info *info);
45 
46 int acpi_gpio_count(struct device *dev, const char *con_id);
47 #else
48 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
49 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
50 
51 static inline void
52 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
53 
54 static inline void
55 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
56 
57 static inline struct gpio_desc *
58 acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
59 			int index, struct acpi_gpio_info *info)
60 {
61 	return ERR_PTR(-ENOSYS);
62 }
63 
64 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
65 {
66 	return -ENODEV;
67 }
68 #endif
69 
70 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
71 		   const char *list_name, int index, enum of_gpio_flags *flags);
72 
73 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
74 
75 extern struct spinlock gpio_lock;
76 extern struct list_head gpio_chips;
77 
78 struct gpio_desc {
79 	struct gpio_chip	*chip;
80 	unsigned long		flags;
81 /* flag symbols are bit numbers */
82 #define FLAG_REQUESTED	0
83 #define FLAG_IS_OUT	1
84 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
85 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
86 #define FLAG_TRIG_FALL	4	/* trigger on falling edge */
87 #define FLAG_TRIG_RISE	5	/* trigger on rising edge */
88 #define FLAG_ACTIVE_LOW	6	/* value has active low */
89 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
90 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
91 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
92 #define FLAG_SYSFS_DIR	10	/* show sysfs direction attribute */
93 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
94 
95 #define ID_SHIFT	16	/* add new flags before this one */
96 
97 #define GPIO_FLAGS_MASK		((1 << ID_SHIFT) - 1)
98 #define GPIO_TRIGGER_MASK	(BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
99 
100 	const char		*label;
101 };
102 
103 int gpiod_request(struct gpio_desc *desc, const char *label);
104 void gpiod_free(struct gpio_desc *desc);
105 int gpiod_hog(struct gpio_desc *desc, const char *name,
106 		unsigned long lflags, enum gpiod_flags dflags);
107 
108 /*
109  * Return the GPIO number of the passed descriptor relative to its chip
110  */
111 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
112 {
113 	return desc - &desc->chip->desc[0];
114 }
115 
116 /* With descriptor prefix */
117 
118 #define gpiod_emerg(desc, fmt, ...)					       \
119 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
120 		 ##__VA_ARGS__)
121 #define gpiod_crit(desc, fmt, ...)					       \
122 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
123 		 ##__VA_ARGS__)
124 #define gpiod_err(desc, fmt, ...)					       \
125 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
126 		 ##__VA_ARGS__)
127 #define gpiod_warn(desc, fmt, ...)					       \
128 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
129 		 ##__VA_ARGS__)
130 #define gpiod_info(desc, fmt, ...)					       \
131 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
132 		 ##__VA_ARGS__)
133 #define gpiod_dbg(desc, fmt, ...)					       \
134 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
135 		 ##__VA_ARGS__)
136 
137 /* With chip prefix */
138 
139 #define chip_emerg(chip, fmt, ...)					\
140 	pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
141 #define chip_crit(chip, fmt, ...)					\
142 	pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
143 #define chip_err(chip, fmt, ...)					\
144 	pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
145 #define chip_warn(chip, fmt, ...)					\
146 	pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
147 #define chip_info(chip, fmt, ...)					\
148 	pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
149 #define chip_dbg(chip, fmt, ...)					\
150 	pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
151 
152 #ifdef CONFIG_GPIO_SYSFS
153 
154 int gpiochip_export(struct gpio_chip *chip);
155 void gpiochip_unexport(struct gpio_chip *chip);
156 
157 #else
158 
159 static inline int gpiochip_export(struct gpio_chip *chip)
160 {
161 	return 0;
162 }
163 
164 static inline void gpiochip_unexport(struct gpio_chip *chip)
165 {
166 }
167 
168 #endif /* CONFIG_GPIO_SYSFS */
169 
170 #endif /* GPIOLIB_H */
171