xref: /openbmc/linux/drivers/gpio/gpiolib.h (revision d0b5e15f)
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 /**
21  * struct acpi_gpio_info - ACPI GPIO specific information
22  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
23  * @active_low: in case of @gpioint, the pin is active low
24  */
25 struct acpi_gpio_info {
26 	bool gpioint;
27 	bool active_low;
28 };
29 
30 #ifdef CONFIG_ACPI
31 void acpi_gpiochip_add(struct gpio_chip *chip);
32 void acpi_gpiochip_remove(struct gpio_chip *chip);
33 
34 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
35 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
36 
37 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
38 					  const char *propname, int index,
39 					  struct acpi_gpio_info *info);
40 #else
41 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
42 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
43 
44 static inline void
45 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
46 
47 static inline void
48 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
49 
50 static inline struct gpio_desc *
51 acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
52 			int index, struct acpi_gpio_info *info)
53 {
54 	return ERR_PTR(-ENOSYS);
55 }
56 #endif
57 
58 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
59 		   const char *list_name, int index, enum of_gpio_flags *flags);
60 
61 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
62 
63 extern struct spinlock gpio_lock;
64 extern struct list_head gpio_chips;
65 
66 struct gpio_desc {
67 	struct gpio_chip	*chip;
68 	unsigned long		flags;
69 /* flag symbols are bit numbers */
70 #define FLAG_REQUESTED	0
71 #define FLAG_IS_OUT	1
72 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
73 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
74 #define FLAG_TRIG_FALL	4	/* trigger on falling edge */
75 #define FLAG_TRIG_RISE	5	/* trigger on rising edge */
76 #define FLAG_ACTIVE_LOW	6	/* value has active low */
77 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
78 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
79 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
80 #define FLAG_SYSFS_DIR	10	/* show sysfs direction attribute */
81 
82 #define ID_SHIFT	16	/* add new flags before this one */
83 
84 #define GPIO_FLAGS_MASK		((1 << ID_SHIFT) - 1)
85 #define GPIO_TRIGGER_MASK	(BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
86 
87 	const char		*label;
88 };
89 
90 int gpiod_request(struct gpio_desc *desc, const char *label);
91 void gpiod_free(struct gpio_desc *desc);
92 
93 /*
94  * Return the GPIO number of the passed descriptor relative to its chip
95  */
96 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
97 {
98 	return desc - &desc->chip->desc[0];
99 }
100 
101 /* With descriptor prefix */
102 
103 #define gpiod_emerg(desc, fmt, ...)					       \
104 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
105 		 ##__VA_ARGS__)
106 #define gpiod_crit(desc, fmt, ...)					       \
107 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
108 		 ##__VA_ARGS__)
109 #define gpiod_err(desc, fmt, ...)					       \
110 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
111 		 ##__VA_ARGS__)
112 #define gpiod_warn(desc, fmt, ...)					       \
113 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
114 		 ##__VA_ARGS__)
115 #define gpiod_info(desc, fmt, ...)					       \
116 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
117 		 ##__VA_ARGS__)
118 #define gpiod_dbg(desc, fmt, ...)					       \
119 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
120 		 ##__VA_ARGS__)
121 
122 /* With chip prefix */
123 
124 #define chip_emerg(chip, fmt, ...)					\
125 	pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
126 #define chip_crit(chip, fmt, ...)					\
127 	pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
128 #define chip_err(chip, fmt, ...)					\
129 	pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
130 #define chip_warn(chip, fmt, ...)					\
131 	pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
132 #define chip_info(chip, fmt, ...)					\
133 	pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
134 #define chip_dbg(chip, fmt, ...)					\
135 	pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
136 
137 #ifdef CONFIG_GPIO_SYSFS
138 
139 int gpiochip_export(struct gpio_chip *chip);
140 void gpiochip_unexport(struct gpio_chip *chip);
141 
142 #else
143 
144 static inline int gpiochip_export(struct gpio_chip *chip)
145 {
146 	return 0;
147 }
148 
149 static inline void gpiochip_unexport(struct gpio_chip *chip)
150 {
151 }
152 
153 #endif /* CONFIG_GPIO_SYSFS */
154 
155 #endif /* GPIOLIB_H */
156