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