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#include <linux/workqueue.h>
 21
 22#define GPIOCHIP_NAME	"gpiochip"
 23
 24/**
 25 * struct gpio_device - internal state container for GPIO devices
 26 * @dev: the GPIO device struct
 27 * @chrdev: character device for the GPIO device
 28 * @id: numerical ID number for the GPIO chip
 29 * @mockdev: class device used by the deprecated sysfs interface (may be
 30 * NULL)
 31 * @owner: helps prevent removal of modules exporting active GPIOs
 32 * @chip: pointer to the corresponding gpiochip, holding static
 33 * data for this device
 34 * @descs: array of ngpio descriptors.
 35 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users
 36 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
 37 * of the @descs array.
 38 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
 39 * implying that they cannot be used from atomic context
 40 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
 41 * at device creation time.
 42 * @label: a descriptive name for the GPIO device, such as the part number
 43 * or name of the IP component in a System on Chip.
 44 * @data: per-instance data assigned by the driver
 45 * @list: links gpio_device:s together for traversal
 46 * @line_state_notifier: used to notify subscribers about lines being
 47 *                       requested, released or reconfigured
 48 * @line_state_wq: used to emit line state events from a separate thread in
 49 *                 process context
 50 * @device_notifier: used to notify character device wait queues about the GPIO
 51 *                   device being unregistered
 52 * @srcu: protects the pointer to the underlying GPIO chip
 53 * @pin_ranges: range of pins served by the GPIO driver
 54 *
 55 * This state container holds most of the runtime variable data
 56 * for a GPIO device and can hold references and live on after the
 57 * GPIO chip has been removed, if it is still being used from
 58 * userspace.
 59 */
 60struct gpio_device {
 61	struct device		dev;
 62	struct cdev		chrdev;
 63	int			id;
 64	struct device		*mockdev;
 65	struct module		*owner;
 66	struct gpio_chip __rcu	*chip;
 67	struct gpio_desc	*descs;
 68	struct srcu_struct	desc_srcu;
 69	unsigned int		base;
 70	u16			ngpio;
 71	bool			can_sleep;
 72	const char		*label;
 73	void			*data;
 74	struct list_head        list;
 75	struct atomic_notifier_head line_state_notifier;
 76	struct workqueue_struct	*line_state_wq;
 77	struct blocking_notifier_head device_notifier;
 78	struct srcu_struct	srcu;
 79
 80#ifdef CONFIG_PINCTRL
 81	/*
 82	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
 83	 * describe the actual pin range which they serve in an SoC. This
 84	 * information would be used by pinctrl subsystem to configure
 85	 * corresponding pins for gpio usage.
 86	 */
 87	struct list_head pin_ranges;
 88#endif
 89};
 90
 91static inline struct gpio_device *to_gpio_device(struct device *dev)
 92{
 93	return container_of(dev, struct gpio_device, dev);
 94}
 95
 96/* GPIO suffixes used for ACPI and device tree lookup */
 97extern const char *const gpio_suffixes[];
 98
 99#define for_each_gpio_property_name(propname, con_id)					\
100	for (const char * const *__suffixes = gpio_suffixes;				\
101	     *__suffixes && ({								\
102		const char *__gs = *__suffixes;						\
103											\
104		if (con_id)								\
105			snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs);	\
106		else									\
107			snprintf(propname, sizeof(propname), "%s", __gs);		\
108		1;									\
109	     });									\
110	     __suffixes++)
111
112/**
113 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
114 *
115 * @desc:		Array of pointers to the GPIO descriptors
116 * @size:		Number of elements in desc
117 * @gdev:		Parent GPIO device
118 * @get_mask:		Get mask used in fastpath
119 * @set_mask:		Set mask used in fastpath
120 * @invert_mask:	Invert mask used in fastpath
121 *
122 * This structure is attached to struct gpiod_descs obtained from
123 * gpiod_get_array() and can be passed back to get/set array functions in order
124 * to activate fast processing path if applicable.
125 */
126struct gpio_array {
127	struct gpio_desc	**desc;
128	unsigned int		size;
129	struct gpio_device	*gdev;
130	unsigned long		*get_mask;
131	unsigned long		*set_mask;
132	unsigned long		invert_mask[];
133};
134
135#define for_each_gpio_desc(gc, desc)					\
136	for (unsigned int __i = 0;					\
137	     __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i));	\
138	     __i++)							\
139
140#define for_each_gpio_desc_with_flag(gc, desc, flag)			\
141	for_each_gpio_desc(gc, desc)					\
142		if (!test_bit(flag, &desc->flags)) {} else
143
144int gpiod_get_array_value_complex(bool raw, bool can_sleep,
145				  unsigned int array_size,
146				  struct gpio_desc **desc_array,
147				  struct gpio_array *array_info,
148				  unsigned long *value_bitmap);
149int gpiod_set_array_value_complex(bool raw, bool can_sleep,
150				  unsigned int array_size,
151				  struct gpio_desc **desc_array,
152				  struct gpio_array *array_info,
153				  unsigned long *value_bitmap);
154
155int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
156
157void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
158int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value);
159int gpiod_direction_input_nonotify(struct gpio_desc *desc);
160
161struct gpio_desc_label {
162	struct rcu_head rh;
163	char str[];
164};
165
166/**
167 * struct gpio_desc - Opaque descriptor for a GPIO
168 *
169 * @gdev:		Pointer to the parent GPIO device
170 * @flags:		Binary descriptor flags
171 * @label:		Name of the consumer
172 * @name:		Line name
173 * @hog:		Pointer to the device node that hogs this line (if any)
174 * @debounce_period_us:	Debounce period in microseconds
175 *
176 * These are obtained using gpiod_get() and are preferable to the old
177 * integer-based handles.
178 *
179 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
180 * valid until the GPIO is released.
181 */
182struct gpio_desc {
183	struct gpio_device	*gdev;
184	unsigned long		flags;
185/* flag symbols are bit numbers */
186#define FLAG_REQUESTED	0
187#define FLAG_IS_OUT	1
188#define FLAG_EXPORT	2	/* protected by sysfs_lock */
189#define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
190#define FLAG_ACTIVE_LOW	6	/* value has active low */
191#define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
192#define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
193#define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
194#define FLAG_IRQ_IS_ENABLED 10	/* GPIO is connected to an enabled IRQ */
195#define FLAG_IS_HOGGED	11	/* GPIO is hogged */
196#define FLAG_TRANSITORY 12	/* GPIO may lose value in sleep or reset */
197#define FLAG_PULL_UP    13	/* GPIO has pull up enabled */
198#define FLAG_PULL_DOWN  14	/* GPIO has pull down enabled */
199#define FLAG_BIAS_DISABLE    15	/* GPIO has pull disabled */
200#define FLAG_EDGE_RISING     16	/* GPIO CDEV detects rising edge events */
201#define FLAG_EDGE_FALLING    17	/* GPIO CDEV detects falling edge events */
202#define FLAG_EVENT_CLOCK_REALTIME	18 /* GPIO CDEV reports REALTIME timestamps in events */
203#define FLAG_EVENT_CLOCK_HTE		19 /* GPIO CDEV reports hardware timestamps in events */
204
205	/* Connection label */
206	struct gpio_desc_label __rcu *label;
207	/* Name of the GPIO */
208	const char		*name;
209#ifdef CONFIG_OF_DYNAMIC
210	struct device_node	*hog;
211#endif
212#ifdef CONFIG_GPIO_CDEV
213	/* debounce period in microseconds */
214	unsigned int		debounce_period_us;
215#endif
216};
217
218#define gpiod_not_found(desc)		(IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
219
220struct gpio_chip_guard {
221	struct gpio_device *gdev;
222	struct gpio_chip *gc;
223	int idx;
224};
225
226DEFINE_CLASS(gpio_chip_guard,
227	     struct gpio_chip_guard,
228	     srcu_read_unlock(&_T.gdev->srcu, _T.idx),
229	     ({
230		struct gpio_chip_guard _guard;
231
232		_guard.gdev = desc->gdev;
233		_guard.idx = srcu_read_lock(&_guard.gdev->srcu);
234		_guard.gc = srcu_dereference(_guard.gdev->chip,
235					     &_guard.gdev->srcu);
236
237		_guard;
238	     }),
239	     struct gpio_desc *desc)
240
241int gpiod_request(struct gpio_desc *desc, const char *label);
242void gpiod_free(struct gpio_desc *desc);
243
244static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
245{
246	int ret;
247
248	ret = gpiod_request(desc, label);
249	if (ret == -EPROBE_DEFER)
250		ret = -ENODEV;
251
252	return ret;
253}
254
255struct gpio_desc *gpiod_find_and_request(struct device *consumer,
256					 struct fwnode_handle *fwnode,
257					 const char *con_id,
258					 unsigned int idx,
259					 enum gpiod_flags flags,
260					 const char *label,
261					 bool platform_lookup_allowed);
262
263int gpio_do_set_config(struct gpio_desc *desc, unsigned long config);
264int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
265		unsigned long lflags, enum gpiod_flags dflags);
266int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
267int gpiod_hog(struct gpio_desc *desc, const char *name,
268		unsigned long lflags, enum gpiod_flags dflags);
269int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
270struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
271const char *gpiod_get_label(struct gpio_desc *desc);
272
273/*
274 * Return the GPIO number of the passed descriptor relative to its chip
275 */
276static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
277{
278	return desc - &desc->gdev->descs[0];
279}
280
281/* With descriptor prefix */
282
283#define gpiod_err(desc, fmt, ...) \
284do { \
285	scoped_guard(srcu, &desc->gdev->desc_srcu) { \
286		pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
287		       gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
288	} \
289} while (0)
290
291#define gpiod_warn(desc, fmt, ...) \
292do { \
293	scoped_guard(srcu, &desc->gdev->desc_srcu) { \
294		pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
295			gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
296	} \
297} while (0)
298
299#define gpiod_dbg(desc, fmt, ...) \
300do { \
301	scoped_guard(srcu, &desc->gdev->desc_srcu) { \
302		pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
303			 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
304	} \
305} while (0)
306
307/* With chip prefix */
308
309#define chip_err(gc, fmt, ...)					\
310	dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
311#define chip_warn(gc, fmt, ...)					\
312	dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
313#define chip_info(gc, fmt, ...)					\
314	dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
315#define chip_dbg(gc, fmt, ...)					\
316	dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
317
318#endif /* GPIOLIB_H */