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/cdev.h>
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/gpio/consumer.h> /* for enum gpiod_flags */
16#include <linux/gpio/driver.h>
17#include <linux/module.h>
18#include <linux/notifier.h>
19#include <linux/srcu.h>
20
21#define GPIOCHIP_NAME "gpiochip"
22
23/**
24 * struct gpio_device - internal state container for GPIO devices
25 * @dev: the GPIO device struct
26 * @chrdev: character device for the GPIO device
27 * @id: numerical ID number for the GPIO chip
28 * @mockdev: class device used by the deprecated sysfs interface (may be
29 * NULL)
30 * @owner: helps prevent removal of modules exporting active GPIOs
31 * @chip: pointer to the corresponding gpiochip, holding static
32 * data for this device
33 * @descs: array of ngpio descriptors.
34 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
35 * of the @descs array.
36 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
37 * implying that they cannot be used from atomic context
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 * @line_state_notifier: used to notify subscribers about lines being
45 * requested, released or reconfigured
46 * @device_notifier: used to notify character device wait queues about the GPIO
47 * device being unregistered
48 * @srcu: protects the pointer to the underlying GPIO chip
49 * @pin_ranges: range of pins served by the GPIO driver
50 *
51 * This state container holds most of the runtime variable data
52 * for a GPIO device and can hold references and live on after the
53 * GPIO chip has been removed, if it is still being used from
54 * userspace.
55 */
56struct gpio_device {
57 struct device dev;
58 struct cdev chrdev;
59 int id;
60 struct device *mockdev;
61 struct module *owner;
62 struct gpio_chip __rcu *chip;
63 struct gpio_desc *descs;
64 int base;
65 u16 ngpio;
66 bool can_sleep;
67 const char *label;
68 void *data;
69 struct list_head list;
70 struct blocking_notifier_head line_state_notifier;
71 struct blocking_notifier_head device_notifier;
72 struct srcu_struct srcu;
73
74#ifdef CONFIG_PINCTRL
75 /*
76 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
77 * describe the actual pin range which they serve in an SoC. This
78 * information would be used by pinctrl subsystem to configure
79 * corresponding pins for gpio usage.
80 */
81 struct list_head pin_ranges;
82#endif
83};
84
85static inline struct gpio_device *to_gpio_device(struct device *dev)
86{
87 return container_of(dev, struct gpio_device, dev);
88}
89
90/* gpio suffixes used for ACPI and device tree lookup */
91static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
92
93/**
94 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
95 *
96 * @desc: Array of pointers to the GPIO descriptors
97 * @size: Number of elements in desc
98 * @chip: Parent GPIO chip
99 * @get_mask: Get mask used in fastpath
100 * @set_mask: Set mask used in fastpath
101 * @invert_mask: Invert mask used in fastpath
102 *
103 * This structure is attached to struct gpiod_descs obtained from
104 * gpiod_get_array() and can be passed back to get/set array functions in order
105 * to activate fast processing path if applicable.
106 */
107struct gpio_array {
108 struct gpio_desc **desc;
109 unsigned int size;
110 struct gpio_chip *chip;
111 unsigned long *get_mask;
112 unsigned long *set_mask;
113 unsigned long invert_mask[];
114};
115
116#define for_each_gpio_desc(gc, desc) \
117 for (unsigned int __i = 0; \
118 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
119 __i++) \
120
121#define for_each_gpio_desc_with_flag(gc, desc, flag) \
122 for_each_gpio_desc(gc, desc) \
123 if (!test_bit(flag, &desc->flags)) {} else
124
125int gpiod_get_array_value_complex(bool raw, bool can_sleep,
126 unsigned int array_size,
127 struct gpio_desc **desc_array,
128 struct gpio_array *array_info,
129 unsigned long *value_bitmap);
130int gpiod_set_array_value_complex(bool raw, bool can_sleep,
131 unsigned int array_size,
132 struct gpio_desc **desc_array,
133 struct gpio_array *array_info,
134 unsigned long *value_bitmap);
135
136int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
137
138void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
139
140/**
141 * struct gpio_desc - Opaque descriptor for a GPIO
142 *
143 * @gdev: Pointer to the parent GPIO device
144 * @flags: Binary descriptor flags
145 * @label: Name of the consumer
146 * @name: Line name
147 * @hog: Pointer to the device node that hogs this line (if any)
148 * @srcu: SRCU struct protecting the label pointer.
149 *
150 * These are obtained using gpiod_get() and are preferable to the old
151 * integer-based handles.
152 *
153 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
154 * valid until the GPIO is released.
155 */
156struct gpio_desc {
157 struct gpio_device *gdev;
158 unsigned long flags;
159/* flag symbols are bit numbers */
160#define FLAG_REQUESTED 0
161#define FLAG_IS_OUT 1
162#define FLAG_EXPORT 2 /* protected by sysfs_lock */
163#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
164#define FLAG_ACTIVE_LOW 6 /* value has active low */
165#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
166#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
167#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
168#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
169#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
170#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
171#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
172#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
173#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
174#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
175#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
176#define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
177#define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
178
179 /* Connection label */
180 const char __rcu *label;
181 /* Name of the GPIO */
182 const char *name;
183#ifdef CONFIG_OF_DYNAMIC
184 struct device_node *hog;
185#endif
186 struct srcu_struct srcu;
187};
188
189#define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
190
191struct gpio_chip_guard {
192 struct gpio_device *gdev;
193 struct gpio_chip *gc;
194 int idx;
195};
196
197DEFINE_CLASS(gpio_chip_guard,
198 struct gpio_chip_guard,
199 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
200 ({
201 struct gpio_chip_guard _guard;
202
203 _guard.gdev = desc->gdev;
204 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
205 _guard.gc = srcu_dereference(_guard.gdev->chip,
206 &_guard.gdev->srcu);
207
208 _guard;
209 }),
210 struct gpio_desc *desc)
211
212int gpiod_request(struct gpio_desc *desc, const char *label);
213void gpiod_free(struct gpio_desc *desc);
214
215static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
216{
217 int ret;
218
219 ret = gpiod_request(desc, label);
220 if (ret == -EPROBE_DEFER)
221 ret = -ENODEV;
222
223 return ret;
224}
225
226struct gpio_desc *gpiod_find_and_request(struct device *consumer,
227 struct fwnode_handle *fwnode,
228 const char *con_id,
229 unsigned int idx,
230 enum gpiod_flags flags,
231 const char *label,
232 bool platform_lookup_allowed);
233
234int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
235 unsigned long lflags, enum gpiod_flags dflags);
236int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
237int gpiod_hog(struct gpio_desc *desc, const char *name,
238 unsigned long lflags, enum gpiod_flags dflags);
239int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
240const char *gpiod_get_label(struct gpio_desc *desc);
241
242/*
243 * Return the GPIO number of the passed descriptor relative to its chip
244 */
245static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
246{
247 return desc - &desc->gdev->descs[0];
248}
249
250/* With descriptor prefix */
251
252#define gpiod_err(desc, fmt, ...) \
253do { \
254 scoped_guard(srcu, &desc->srcu) { \
255 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
256 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
257 } \
258} while (0)
259
260#define gpiod_warn(desc, fmt, ...) \
261do { \
262 scoped_guard(srcu, &desc->srcu) { \
263 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
264 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
265 } \
266} while (0)
267
268#define gpiod_dbg(desc, fmt, ...) \
269do { \
270 scoped_guard(srcu, &desc->srcu) { \
271 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
272 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
273 } \
274} while (0)
275
276/* With chip prefix */
277
278#define chip_err(gc, fmt, ...) \
279 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
280#define chip_warn(gc, fmt, ...) \
281 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
282#define chip_info(gc, fmt, ...) \
283 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
284#define chip_dbg(gc, fmt, ...) \
285 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
286
287#endif /* GPIOLIB_H */
288

source code of linux/drivers/gpio/gpiolib.h