xref: /openbmc/linux/drivers/gpio/gpiolib.h (revision 7587eb18)
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/gpio/driver.h>
16 #include <linux/err.h>
17 #include <linux/device.h>
18 #include <linux/module.h>
19 #include <linux/cdev.h>
20 
21 enum of_gpio_flags;
22 enum gpiod_flags;
23 struct acpi_device;
24 
25 /**
26  * struct gpio_device - internal state container for GPIO devices
27  * @id: numerical ID number for the GPIO chip
28  * @dev: the GPIO device struct
29  * @chrdev: character device for the GPIO device
30  * @mockdev: class device used by the deprecated sysfs interface (may be
31  * NULL)
32  * @owner: helps prevent removal of modules exporting active GPIOs
33  * @chip: pointer to the corresponding gpiochip, holding static
34  * data for this device
35  * @descs: array of ngpio descriptors.
36  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
37  * of the @descs array.
38  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
39  * at device creation time.
40  * @label: a descriptive name for the GPIO device, such as the part number
41  * or name of the IP component in a System on Chip.
42  * @data: per-instance data assigned by the driver
43  * @list: links gpio_device:s together for traversal
44  *
45  * This state container holds most of the runtime variable data
46  * for a GPIO device and can hold references and live on after the
47  * GPIO chip has been removed, if it is still being used from
48  * userspace.
49  */
50 struct gpio_device {
51 	int			id;
52 	struct device		dev;
53 	struct cdev		chrdev;
54 	struct device		*mockdev;
55 	struct module		*owner;
56 	struct gpio_chip	*chip;
57 	struct gpio_desc	*descs;
58 	int			base;
59 	u16			ngpio;
60 	char			*label;
61 	void			*data;
62 	struct list_head        list;
63 
64 #ifdef CONFIG_PINCTRL
65 	/*
66 	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
67 	 * describe the actual pin range which they serve in an SoC. This
68 	 * information would be used by pinctrl subsystem to configure
69 	 * corresponding pins for gpio usage.
70 	 */
71 	struct list_head pin_ranges;
72 #endif
73 };
74 
75 /**
76  * struct acpi_gpio_info - ACPI GPIO specific information
77  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
78  * @active_low: in case of @gpioint, the pin is active low
79  */
80 struct acpi_gpio_info {
81 	bool gpioint;
82 	int polarity;
83 	int triggering;
84 };
85 
86 /* gpio suffixes used for ACPI and device tree lookup */
87 static const char * const gpio_suffixes[] = { "gpios", "gpio" };
88 
89 #ifdef CONFIG_ACPI
90 void acpi_gpiochip_add(struct gpio_chip *chip);
91 void acpi_gpiochip_remove(struct gpio_chip *chip);
92 
93 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
94 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
95 
96 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
97 					  const char *propname, int index,
98 					  struct acpi_gpio_info *info);
99 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
100 				      const char *propname, int index,
101 				      struct acpi_gpio_info *info);
102 
103 int acpi_gpio_count(struct device *dev, const char *con_id);
104 
105 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
106 #else
107 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
108 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
109 
110 static inline void
111 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
112 
113 static inline void
114 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
115 
116 static inline struct gpio_desc *
117 acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
118 			int index, struct acpi_gpio_info *info)
119 {
120 	return ERR_PTR(-ENOSYS);
121 }
122 static inline struct gpio_desc *
123 acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
124 		    int index, struct acpi_gpio_info *info)
125 {
126 	return ERR_PTR(-ENXIO);
127 }
128 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
129 {
130 	return -ENODEV;
131 }
132 
133 static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
134 					    const char *con_id)
135 {
136 	return false;
137 }
138 #endif
139 
140 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
141 		   const char *list_name, int index, enum of_gpio_flags *flags);
142 
143 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
144 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
145 				   unsigned int array_size,
146 				   struct gpio_desc **desc_array,
147 				   int *value_array);
148 
149 extern struct spinlock gpio_lock;
150 extern struct list_head gpio_devices;
151 
152 struct gpio_desc {
153 	struct gpio_device	*gdev;
154 	unsigned long		flags;
155 /* flag symbols are bit numbers */
156 #define FLAG_REQUESTED	0
157 #define FLAG_IS_OUT	1
158 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
159 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
160 #define FLAG_ACTIVE_LOW	6	/* value has active low */
161 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
162 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
163 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
164 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
165 
166 	/* Connection label */
167 	const char		*label;
168 	/* Name of the GPIO */
169 	const char		*name;
170 };
171 
172 int gpiod_request(struct gpio_desc *desc, const char *label);
173 void gpiod_free(struct gpio_desc *desc);
174 int gpiod_hog(struct gpio_desc *desc, const char *name,
175 		unsigned long lflags, enum gpiod_flags dflags);
176 
177 /*
178  * Return the GPIO number of the passed descriptor relative to its chip
179  */
180 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
181 {
182 	return desc - &desc->gdev->descs[0];
183 }
184 
185 /* With descriptor prefix */
186 
187 #define gpiod_emerg(desc, fmt, ...)					       \
188 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
189 		 ##__VA_ARGS__)
190 #define gpiod_crit(desc, fmt, ...)					       \
191 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
192 		 ##__VA_ARGS__)
193 #define gpiod_err(desc, fmt, ...)					       \
194 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
195 		 ##__VA_ARGS__)
196 #define gpiod_warn(desc, fmt, ...)					       \
197 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
198 		 ##__VA_ARGS__)
199 #define gpiod_info(desc, fmt, ...)					       \
200 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
201 		 ##__VA_ARGS__)
202 #define gpiod_dbg(desc, fmt, ...)					       \
203 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
204 		 ##__VA_ARGS__)
205 
206 /* With chip prefix */
207 
208 #define chip_emerg(chip, fmt, ...)					\
209 	dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
210 #define chip_crit(chip, fmt, ...)					\
211 	dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
212 #define chip_err(chip, fmt, ...)					\
213 	dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
214 #define chip_warn(chip, fmt, ...)					\
215 	dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
216 #define chip_info(chip, fmt, ...)					\
217 	dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
218 #define chip_dbg(chip, fmt, ...)					\
219 	dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
220 
221 #ifdef CONFIG_GPIO_SYSFS
222 
223 int gpiochip_sysfs_register(struct gpio_device *gdev);
224 void gpiochip_sysfs_unregister(struct gpio_device *gdev);
225 
226 #else
227 
228 static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
229 {
230 	return 0;
231 }
232 
233 static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
234 {
235 }
236 
237 #endif /* CONFIG_GPIO_SYSFS */
238 
239 #endif /* GPIOLIB_H */
240