tjh.dev
Linux kernel mirror (for testing)
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linux
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#include <linux/rwsem.h>
19
20#define GPIOCHIP_NAME "gpiochip"
21
22/**
23 * struct gpio_device - internal state container for GPIO devices
24 * @dev: the GPIO device struct
25 * @chrdev: character device for the GPIO device
26 * @id: numerical ID number for the GPIO chip
27 * @mockdev: class device used by the deprecated sysfs interface (may be
28 * NULL)
29 * @owner: helps prevent removal of modules exporting active GPIOs
30 * @chip: pointer to the corresponding gpiochip, holding static
31 * data for this device
32 * @descs: array of ngpio descriptors.
33 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
34 * of the @descs array.
35 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
36 * at device creation time.
37 * @label: a descriptive name for the GPIO device, such as the part number
38 * or name of the IP component in a System on Chip.
39 * @data: per-instance data assigned by the driver
40 * @list: links gpio_device:s together for traversal
41 * @notifier: used to notify subscribers about lines being requested, released
42 * or reconfigured
43 * @sem: protects the structure from a NULL-pointer dereference of @chip by
44 * user-space operations when the device gets unregistered during
45 * a hot-unplug event
46 * @pin_ranges: range of pins served by the GPIO driver
47 *
48 * This state container holds most of the runtime variable data
49 * for a GPIO device and can hold references and live on after the
50 * GPIO chip has been removed, if it is still being used from
51 * userspace.
52 */
53struct gpio_device {
54 struct device dev;
55 struct cdev chrdev;
56 int id;
57 struct device *mockdev;
58 struct module *owner;
59 struct gpio_chip *chip;
60 struct gpio_desc *descs;
61 int base;
62 u16 ngpio;
63 const char *label;
64 void *data;
65 struct list_head list;
66 struct blocking_notifier_head notifier;
67 struct rw_semaphore sem;
68
69#ifdef CONFIG_PINCTRL
70 /*
71 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
72 * describe the actual pin range which they serve in an SoC. This
73 * information would be used by pinctrl subsystem to configure
74 * corresponding pins for gpio usage.
75 */
76 struct list_head pin_ranges;
77#endif
78};
79
80static inline struct gpio_device *to_gpio_device(struct device *dev)
81{
82 return container_of(dev, struct gpio_device, dev);
83}
84
85static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev)
86{
87 return to_gpio_device(get_device(&gdev->dev));
88}
89
90static inline void gpio_device_put(struct gpio_device *gdev)
91{
92 put_device(&gdev->dev);
93}
94
95/* gpio suffixes used for ACPI and device tree lookup */
96static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
97
98/**
99 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
100 *
101 * @desc: Array of pointers to the GPIO descriptors
102 * @size: Number of elements in desc
103 * @chip: Parent GPIO chip
104 * @get_mask: Get mask used in fastpath
105 * @set_mask: Set mask used in fastpath
106 * @invert_mask: Invert mask used in fastpath
107 *
108 * This structure is attached to struct gpiod_descs obtained from
109 * gpiod_get_array() and can be passed back to get/set array functions in order
110 * to activate fast processing path if applicable.
111 */
112struct gpio_array {
113 struct gpio_desc **desc;
114 unsigned int size;
115 struct gpio_chip *chip;
116 unsigned long *get_mask;
117 unsigned long *set_mask;
118 unsigned long invert_mask[];
119};
120
121struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
122
123#define for_each_gpio_desc(gc, desc) \
124 for (unsigned int __i = 0; \
125 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
126 __i++) \
127
128#define for_each_gpio_desc_with_flag(gc, desc, flag) \
129 for_each_gpio_desc(gc, desc) \
130 if (!test_bit(flag, &desc->flags)) {} else
131
132int gpiod_get_array_value_complex(bool raw, bool can_sleep,
133 unsigned int array_size,
134 struct gpio_desc **desc_array,
135 struct gpio_array *array_info,
136 unsigned long *value_bitmap);
137int gpiod_set_array_value_complex(bool raw, bool can_sleep,
138 unsigned int array_size,
139 struct gpio_desc **desc_array,
140 struct gpio_array *array_info,
141 unsigned long *value_bitmap);
142
143extern spinlock_t gpio_lock;
144extern struct list_head gpio_devices;
145
146
147/**
148 * struct gpio_desc - Opaque descriptor for a GPIO
149 *
150 * @gdev: Pointer to the parent GPIO device
151 * @flags: Binary descriptor flags
152 * @label: Name of the consumer
153 * @name: Line name
154 * @hog: Pointer to the device node that hogs this line (if any)
155 * @debounce_period_us: Debounce period in microseconds
156 *
157 * These are obtained using gpiod_get() and are preferable to the old
158 * integer-based handles.
159 *
160 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
161 * valid until the GPIO is released.
162 */
163struct gpio_desc {
164 struct gpio_device *gdev;
165 unsigned long flags;
166/* flag symbols are bit numbers */
167#define FLAG_REQUESTED 0
168#define FLAG_IS_OUT 1
169#define FLAG_EXPORT 2 /* protected by sysfs_lock */
170#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
171#define FLAG_ACTIVE_LOW 6 /* value has active low */
172#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
173#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
174#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
175#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
176#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
177#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
178#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
179#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
180#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
181#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
182#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
183#define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
184#define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
185
186 /* Connection label */
187 const char *label;
188 /* Name of the GPIO */
189 const char *name;
190#ifdef CONFIG_OF_DYNAMIC
191 struct device_node *hog;
192#endif
193#ifdef CONFIG_GPIO_CDEV
194 /* debounce period in microseconds */
195 unsigned int debounce_period_us;
196#endif
197};
198
199#define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
200
201int gpiod_request(struct gpio_desc *desc, const char *label);
202void gpiod_free(struct gpio_desc *desc);
203
204static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
205{
206 int ret;
207
208 ret = gpiod_request(desc, label);
209 if (ret == -EPROBE_DEFER)
210 ret = -ENODEV;
211
212 return ret;
213}
214
215int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
216 unsigned long lflags, enum gpiod_flags dflags);
217int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
218int gpiod_hog(struct gpio_desc *desc, const char *name,
219 unsigned long lflags, enum gpiod_flags dflags);
220
221/*
222 * Return the GPIO number of the passed descriptor relative to its chip
223 */
224static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
225{
226 return desc - &desc->gdev->descs[0];
227}
228
229/* With descriptor prefix */
230
231#define gpiod_emerg(desc, fmt, ...) \
232 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
233 ##__VA_ARGS__)
234#define gpiod_crit(desc, fmt, ...) \
235 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
236 ##__VA_ARGS__)
237#define gpiod_err(desc, fmt, ...) \
238 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
239 ##__VA_ARGS__)
240#define gpiod_warn(desc, fmt, ...) \
241 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
242 ##__VA_ARGS__)
243#define gpiod_info(desc, fmt, ...) \
244 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
245 ##__VA_ARGS__)
246#define gpiod_dbg(desc, fmt, ...) \
247 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
248 ##__VA_ARGS__)
249
250/* With chip prefix */
251
252#define chip_emerg(gc, fmt, ...) \
253 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
254#define chip_crit(gc, fmt, ...) \
255 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
256#define chip_err(gc, fmt, ...) \
257 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
258#define chip_warn(gc, fmt, ...) \
259 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
260#define chip_info(gc, fmt, ...) \
261 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
262#define chip_dbg(gc, fmt, ...) \
263 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
264
265#endif /* GPIOLIB_H */