1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Internal GPIO functions.
5 * Copyright (C) 2013, Intel Corporation
6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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>
21 #define GPIOCHIP_NAME "gpiochip"
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
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
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
60 struct device *mockdev;
62 struct gpio_chip __rcu *chip;
63 struct gpio_desc *descs;
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;
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.
81 struct list_head pin_ranges;
85 static inline struct gpio_device *to_gpio_device(struct device *dev)
87 return container_of(dev, struct gpio_device, dev);
90 /* gpio suffixes used for ACPI and device tree lookup */
91 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
94 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
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
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.
108 struct gpio_desc **desc;
110 struct gpio_chip *chip;
111 unsigned long *get_mask;
112 unsigned long *set_mask;
113 unsigned long invert_mask[];
116 #define for_each_gpio_desc(gc, desc) \
117 for (unsigned int __i = 0; \
118 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
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
125 int 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);
130 int 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);
136 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
138 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
141 * struct gpio_desc - Opaque descriptor for a GPIO
143 * @gdev: Pointer to the parent GPIO device
144 * @flags: Binary descriptor flags
145 * @label: Name of the consumer
147 * @hog: Pointer to the device node that hogs this line (if any)
148 * @srcu: SRCU struct protecting the label pointer.
150 * These are obtained using gpiod_get() and are preferable to the old
151 * integer-based handles.
153 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
154 * valid until the GPIO is released.
157 struct gpio_device *gdev;
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 */
179 /* Connection label */
180 const char __rcu *label;
181 /* Name of the GPIO */
183 #ifdef CONFIG_OF_DYNAMIC
184 struct device_node *hog;
186 struct srcu_struct srcu;
189 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
191 struct gpio_chip_guard {
192 struct gpio_device *gdev;
193 struct gpio_chip *gc;
197 DEFINE_CLASS(gpio_chip_guard,
198 struct gpio_chip_guard,
199 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
201 struct gpio_chip_guard _guard;
203 _guard.gdev = desc->gdev;
204 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
205 _guard.gc = srcu_dereference(_guard.gdev->chip,
210 struct gpio_desc *desc)
212 int gpiod_request(struct gpio_desc *desc, const char *label);
213 void gpiod_free(struct gpio_desc *desc);
215 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
219 ret = gpiod_request(desc, label);
220 if (ret == -EPROBE_DEFER)
226 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
227 struct fwnode_handle *fwnode,
230 enum gpiod_flags flags,
232 bool platform_lookup_allowed);
234 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
235 unsigned long lflags, enum gpiod_flags dflags);
236 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
237 int gpiod_hog(struct gpio_desc *desc, const char *name,
238 unsigned long lflags, enum gpiod_flags dflags);
239 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
240 const char *gpiod_get_label(struct gpio_desc *desc);
243 * Return the GPIO number of the passed descriptor relative to its chip
245 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
247 return desc - &desc->gdev->descs[0];
250 /* With descriptor prefix */
252 #define gpiod_err(desc, fmt, ...) \
254 scoped_guard(srcu, &desc->srcu) { \
255 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
256 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
260 #define gpiod_warn(desc, fmt, ...) \
262 scoped_guard(srcu, &desc->srcu) { \
263 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
264 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
268 #define gpiod_dbg(desc, fmt, ...) \
270 scoped_guard(srcu, &desc->srcu) { \
271 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
272 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
276 /* With chip prefix */
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__)
287 #endif /* GPIOLIB_H */