xref: /openbmc/linux/drivers/gpio/gpiolib.h (revision 8730046c)
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 enum gpio_lookup_flags;
24 struct acpi_device;
25 
26 /**
27  * struct gpio_device - internal state container for GPIO devices
28  * @id: numerical ID number for the GPIO chip
29  * @dev: the GPIO device struct
30  * @chrdev: character device for the GPIO device
31  * @mockdev: class device used by the deprecated sysfs interface (may be
32  * NULL)
33  * @owner: helps prevent removal of modules exporting active GPIOs
34  * @chip: pointer to the corresponding gpiochip, holding static
35  * data for this device
36  * @descs: array of ngpio descriptors.
37  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
38  * of the @descs array.
39  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
40  * at device creation time.
41  * @label: a descriptive name for the GPIO device, such as the part number
42  * or name of the IP component in a System on Chip.
43  * @data: per-instance data assigned by the driver
44  * @list: links gpio_device:s together for traversal
45  *
46  * This state container holds most of the runtime variable data
47  * for a GPIO device and can hold references and live on after the
48  * GPIO chip has been removed, if it is still being used from
49  * userspace.
50  */
51 struct gpio_device {
52 	int			id;
53 	struct device		dev;
54 	struct cdev		chrdev;
55 	struct device		*mockdev;
56 	struct module		*owner;
57 	struct gpio_chip	*chip;
58 	struct gpio_desc	*descs;
59 	int			base;
60 	u16			ngpio;
61 	char			*label;
62 	void			*data;
63 	struct list_head        list;
64 
65 #ifdef CONFIG_PINCTRL
66 	/*
67 	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
68 	 * describe the actual pin range which they serve in an SoC. This
69 	 * information would be used by pinctrl subsystem to configure
70 	 * corresponding pins for gpio usage.
71 	 */
72 	struct list_head pin_ranges;
73 #endif
74 };
75 
76 /**
77  * struct acpi_gpio_info - ACPI GPIO specific information
78  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
79  * @active_low: in case of @gpioint, the pin is active low
80  */
81 struct acpi_gpio_info {
82 	bool gpioint;
83 	int polarity;
84 	int triggering;
85 };
86 
87 /* gpio suffixes used for ACPI and device tree lookup */
88 static const char * const gpio_suffixes[] = { "gpios", "gpio" };
89 
90 #ifdef CONFIG_OF_GPIO
91 struct gpio_desc *of_find_gpio(struct device *dev,
92 			       const char *con_id,
93 			       unsigned int idx,
94 			       enum gpio_lookup_flags *flags);
95 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
96 		   const char *list_name, int index, enum of_gpio_flags *flags);
97 int of_gpiochip_add(struct gpio_chip *gc);
98 void of_gpiochip_remove(struct gpio_chip *gc);
99 #else
100 static inline struct gpio_desc *of_find_gpio(struct device *dev,
101 					     const char *con_id,
102 					     unsigned int idx,
103 					     enum gpio_lookup_flags *flags)
104 {
105 	return ERR_PTR(-ENOENT);
106 }
107 static inline struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
108 		   const char *list_name, int index, enum of_gpio_flags *flags)
109 {
110 	return ERR_PTR(-ENOENT);
111 }
112 static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
113 static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
114 #endif /* CONFIG_OF_GPIO */
115 
116 #ifdef CONFIG_ACPI
117 void acpi_gpiochip_add(struct gpio_chip *chip);
118 void acpi_gpiochip_remove(struct gpio_chip *chip);
119 
120 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
121 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
122 
123 struct gpio_desc *acpi_find_gpio(struct device *dev,
124 				 const char *con_id,
125 				 unsigned int idx,
126 				 enum gpiod_flags flags,
127 				 enum gpio_lookup_flags *lookupflags);
128 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
129 				      const char *propname, int index,
130 				      struct acpi_gpio_info *info);
131 
132 int acpi_gpio_count(struct device *dev, const char *con_id);
133 
134 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
135 #else
136 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
137 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
138 
139 static inline void
140 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
141 
142 static inline void
143 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
144 
145 static inline struct gpio_desc *
146 acpi_find_gpio(struct device *dev, const char *con_id,
147 	       unsigned int idx, enum gpiod_flags flags,
148 	       enum gpio_lookup_flags *lookupflags)
149 {
150 	return ERR_PTR(-ENOENT);
151 }
152 static inline struct gpio_desc *
153 acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
154 		    int index, struct acpi_gpio_info *info)
155 {
156 	return ERR_PTR(-ENXIO);
157 }
158 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
159 {
160 	return -ENODEV;
161 }
162 
163 static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
164 					    const char *con_id)
165 {
166 	return false;
167 }
168 #endif
169 
170 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
171 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
172 				   unsigned int array_size,
173 				   struct gpio_desc **desc_array,
174 				   int *value_array);
175 
176 extern struct spinlock gpio_lock;
177 extern struct list_head gpio_devices;
178 
179 struct gpio_desc {
180 	struct gpio_device	*gdev;
181 	unsigned long		flags;
182 /* flag symbols are bit numbers */
183 #define FLAG_REQUESTED	0
184 #define FLAG_IS_OUT	1
185 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
186 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
187 #define FLAG_ACTIVE_LOW	6	/* value has active low */
188 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
189 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
190 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
191 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
192 
193 	/* Connection label */
194 	const char		*label;
195 	/* Name of the GPIO */
196 	const char		*name;
197 };
198 
199 int gpiod_request(struct gpio_desc *desc, const char *label);
200 void gpiod_free(struct gpio_desc *desc);
201 int gpiod_hog(struct gpio_desc *desc, const char *name,
202 		unsigned long lflags, enum gpiod_flags dflags);
203 
204 /*
205  * Return the GPIO number of the passed descriptor relative to its chip
206  */
207 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
208 {
209 	return desc - &desc->gdev->descs[0];
210 }
211 
212 void devprop_gpiochip_set_names(struct gpio_chip *chip);
213 
214 /* With descriptor prefix */
215 
216 #define gpiod_emerg(desc, fmt, ...)					       \
217 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
218 		 ##__VA_ARGS__)
219 #define gpiod_crit(desc, fmt, ...)					       \
220 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
221 		 ##__VA_ARGS__)
222 #define gpiod_err(desc, fmt, ...)					       \
223 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
224 		 ##__VA_ARGS__)
225 #define gpiod_warn(desc, fmt, ...)					       \
226 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
227 		 ##__VA_ARGS__)
228 #define gpiod_info(desc, fmt, ...)					       \
229 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
230 		 ##__VA_ARGS__)
231 #define gpiod_dbg(desc, fmt, ...)					       \
232 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
233 		 ##__VA_ARGS__)
234 
235 /* With chip prefix */
236 
237 #define chip_emerg(chip, fmt, ...)					\
238 	dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
239 #define chip_crit(chip, fmt, ...)					\
240 	dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
241 #define chip_err(chip, fmt, ...)					\
242 	dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
243 #define chip_warn(chip, fmt, ...)					\
244 	dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
245 #define chip_info(chip, fmt, ...)					\
246 	dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
247 #define chip_dbg(chip, fmt, ...)					\
248 	dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
249 
250 #ifdef CONFIG_GPIO_SYSFS
251 
252 int gpiochip_sysfs_register(struct gpio_device *gdev);
253 void gpiochip_sysfs_unregister(struct gpio_device *gdev);
254 
255 #else
256 
257 static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
258 {
259 	return 0;
260 }
261 
262 static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
263 {
264 }
265 
266 #endif /* CONFIG_GPIO_SYSFS */
267 
268 #endif /* GPIOLIB_H */
269