xref: /openbmc/linux/drivers/gpio/gpiolib.h (revision 3a9a6f3d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Internal GPIO functions.
4  *
5  * Copyright (C) 2013, Intel Corporation
6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
7  */
8 
9 #ifndef GPIOLIB_H
10 #define GPIOLIB_H
11 
12 #include <linux/gpio/driver.h>
13 #include <linux/gpio/consumer.h> /* for enum gpiod_flags */
14 #include <linux/err.h>
15 #include <linux/device.h>
16 #include <linux/module.h>
17 #include <linux/cdev.h>
18 
19 #define GPIOCHIP_NAME	"gpiochip"
20 
21 /**
22  * struct gpio_device - internal state container for GPIO devices
23  * @id: numerical ID number for the GPIO chip
24  * @dev: the GPIO device struct
25  * @chrdev: character device for the GPIO device
26  * @mockdev: class device used by the deprecated sysfs interface (may be
27  * NULL)
28  * @owner: helps prevent removal of modules exporting active GPIOs
29  * @chip: pointer to the corresponding gpiochip, holding static
30  * data for this device
31  * @descs: array of ngpio descriptors.
32  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
33  * of the @descs array.
34  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
35  * at device creation time.
36  * @label: a descriptive name for the GPIO device, such as the part number
37  * or name of the IP component in a System on Chip.
38  * @data: per-instance data assigned by the driver
39  * @list: links gpio_device:s together for traversal
40  *
41  * This state container holds most of the runtime variable data
42  * for a GPIO device and can hold references and live on after the
43  * GPIO chip has been removed, if it is still being used from
44  * userspace.
45  */
46 struct gpio_device {
47 	int			id;
48 	struct device		dev;
49 	struct cdev		chrdev;
50 	struct device		*mockdev;
51 	struct module		*owner;
52 	struct gpio_chip	*chip;
53 	struct gpio_desc	*descs;
54 	int			base;
55 	u16			ngpio;
56 	const char		*label;
57 	void			*data;
58 	struct list_head        list;
59 	struct blocking_notifier_head notifier;
60 
61 #ifdef CONFIG_PINCTRL
62 	/*
63 	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
64 	 * describe the actual pin range which they serve in an SoC. This
65 	 * information would be used by pinctrl subsystem to configure
66 	 * corresponding pins for gpio usage.
67 	 */
68 	struct list_head pin_ranges;
69 #endif
70 };
71 
72 /* gpio suffixes used for ACPI and device tree lookup */
73 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
74 
75 struct gpio_array {
76 	struct gpio_desc	**desc;
77 	unsigned int		size;
78 	struct gpio_chip	*chip;
79 	unsigned long		*get_mask;
80 	unsigned long		*set_mask;
81 	unsigned long		invert_mask[];
82 };
83 
84 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
85 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
86 				  unsigned int array_size,
87 				  struct gpio_desc **desc_array,
88 				  struct gpio_array *array_info,
89 				  unsigned long *value_bitmap);
90 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
91 				  unsigned int array_size,
92 				  struct gpio_desc **desc_array,
93 				  struct gpio_array *array_info,
94 				  unsigned long *value_bitmap);
95 
96 extern spinlock_t gpio_lock;
97 extern struct list_head gpio_devices;
98 
99 struct gpio_desc {
100 	struct gpio_device	*gdev;
101 	unsigned long		flags;
102 /* flag symbols are bit numbers */
103 #define FLAG_REQUESTED	0
104 #define FLAG_IS_OUT	1
105 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
106 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
107 #define FLAG_ACTIVE_LOW	6	/* value has active low */
108 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
109 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
110 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
111 #define FLAG_IRQ_IS_ENABLED 10	/* GPIO is connected to an enabled IRQ */
112 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
113 #define FLAG_TRANSITORY 12	/* GPIO may lose value in sleep or reset */
114 #define FLAG_PULL_UP    13	/* GPIO has pull up enabled */
115 #define FLAG_PULL_DOWN  14	/* GPIO has pull down enabled */
116 #define FLAG_BIAS_DISABLE    15	/* GPIO has pull disabled */
117 #define FLAG_EDGE_RISING     16	/* GPIO CDEV detects rising edge events */
118 #define FLAG_EDGE_FALLING    17	/* GPIO CDEV detects falling edge events */
119 #define FLAG_EVENT_CLOCK_REALTIME	18 /* GPIO CDEV reports REALTIME timestamps in events */
120 
121 	/* Connection label */
122 	const char		*label;
123 	/* Name of the GPIO */
124 	const char		*name;
125 #ifdef CONFIG_OF_DYNAMIC
126 	struct device_node	*hog;
127 #endif
128 #ifdef CONFIG_GPIO_CDEV
129 	/* debounce period in microseconds */
130 	unsigned int		debounce_period_us;
131 #endif
132 };
133 
134 #define gpiod_not_found(desc)		(IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
135 
136 int gpiod_request(struct gpio_desc *desc, const char *label);
137 void gpiod_free(struct gpio_desc *desc);
138 
139 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
140 {
141 	int ret;
142 
143 	ret = gpiod_request(desc, label);
144 	if (ret == -EPROBE_DEFER)
145 		ret = -ENODEV;
146 
147 	return ret;
148 }
149 
150 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
151 		unsigned long lflags, enum gpiod_flags dflags);
152 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
153 int gpiod_hog(struct gpio_desc *desc, const char *name,
154 		unsigned long lflags, enum gpiod_flags dflags);
155 
156 /*
157  * Return the GPIO number of the passed descriptor relative to its chip
158  */
159 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
160 {
161 	return desc - &desc->gdev->descs[0];
162 }
163 
164 /* With descriptor prefix */
165 
166 #define gpiod_emerg(desc, fmt, ...)					       \
167 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
168 		 ##__VA_ARGS__)
169 #define gpiod_crit(desc, fmt, ...)					       \
170 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
171 		 ##__VA_ARGS__)
172 #define gpiod_err(desc, fmt, ...)					       \
173 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
174 		 ##__VA_ARGS__)
175 #define gpiod_warn(desc, fmt, ...)					       \
176 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
177 		 ##__VA_ARGS__)
178 #define gpiod_info(desc, fmt, ...)					       \
179 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
180 		 ##__VA_ARGS__)
181 #define gpiod_dbg(desc, fmt, ...)					       \
182 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
183 		 ##__VA_ARGS__)
184 
185 /* With chip prefix */
186 
187 #define chip_emerg(gc, fmt, ...)					\
188 	dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
189 #define chip_crit(gc, fmt, ...)					\
190 	dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
191 #define chip_err(gc, fmt, ...)					\
192 	dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
193 #define chip_warn(gc, fmt, ...)					\
194 	dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
195 #define chip_info(gc, fmt, ...)					\
196 	dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
197 #define chip_dbg(gc, fmt, ...)					\
198 	dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
199 
200 #endif /* GPIOLIB_H */
201