Loading...
1/*
2 * Internal GPIO functions.
3 *
4 * Copyright (C) 2013, Intel Corporation
5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#ifndef GPIOLIB_H
13#define GPIOLIB_H
14
15#include <linux/gpio/driver.h>
16#include <linux/err.h>
17#include <linux/device.h>
18#include <linux/module.h>
19#include <linux/cdev.h>
20
21enum of_gpio_flags;
22enum gpiod_flags;
23struct acpi_device;
24
25/**
26 * struct gpio_device - internal state container for GPIO devices
27 * @id: numerical ID number for the GPIO chip
28 * @dev: the GPIO device struct
29 * @chrdev: character device for the GPIO device
30 * @mockdev: class device used by the deprecated sysfs interface (may be
31 * NULL)
32 * @owner: helps prevent removal of modules exporting active GPIOs
33 * @chip: pointer to the corresponding gpiochip, holding static
34 * data for this device
35 * @descs: array of ngpio descriptors.
36 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
37 * of the @descs array.
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 *
45 * This state container holds most of the runtime variable data
46 * for a GPIO device and can hold references and live on after the
47 * GPIO chip has been removed, if it is still being used from
48 * userspace.
49 */
50struct gpio_device {
51 int id;
52 struct device dev;
53 struct cdev chrdev;
54 struct device *mockdev;
55 struct module *owner;
56 struct gpio_chip *chip;
57 struct gpio_desc *descs;
58 int base;
59 u16 ngpio;
60 char *label;
61 void *data;
62 struct list_head list;
63
64#ifdef CONFIG_PINCTRL
65 /*
66 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
67 * describe the actual pin range which they serve in an SoC. This
68 * information would be used by pinctrl subsystem to configure
69 * corresponding pins for gpio usage.
70 */
71 struct list_head pin_ranges;
72#endif
73};
74
75/**
76 * struct acpi_gpio_info - ACPI GPIO specific information
77 * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
78 * @active_low: in case of @gpioint, the pin is active low
79 */
80struct acpi_gpio_info {
81 bool gpioint;
82 int polarity;
83 int triggering;
84};
85
86/* gpio suffixes used for ACPI and device tree lookup */
87static const char * const gpio_suffixes[] = { "gpios", "gpio" };
88
89#ifdef CONFIG_ACPI
90void acpi_gpiochip_add(struct gpio_chip *chip);
91void acpi_gpiochip_remove(struct gpio_chip *chip);
92
93void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
94void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
95
96struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
97 const char *propname, int index,
98 struct acpi_gpio_info *info);
99struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
100 const char *propname, int index,
101 struct acpi_gpio_info *info);
102
103int acpi_gpio_count(struct device *dev, const char *con_id);
104
105bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
106#else
107static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
108static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
109
110static inline void
111acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
112
113static inline void
114acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
115
116static inline struct gpio_desc *
117acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
118 int index, struct acpi_gpio_info *info)
119{
120 return ERR_PTR(-ENOSYS);
121}
122static inline struct gpio_desc *
123acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
124 int index, struct acpi_gpio_info *info)
125{
126 return ERR_PTR(-ENXIO);
127}
128static inline int acpi_gpio_count(struct device *dev, const char *con_id)
129{
130 return -ENODEV;
131}
132
133static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
134 const char *con_id)
135{
136 return false;
137}
138#endif
139
140struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
141 const char *list_name, int index, enum of_gpio_flags *flags);
142
143struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
144
145extern struct spinlock gpio_lock;
146extern struct list_head gpio_devices;
147
148struct gpio_desc {
149 struct gpio_device *gdev;
150 unsigned long flags;
151/* flag symbols are bit numbers */
152#define FLAG_REQUESTED 0
153#define FLAG_IS_OUT 1
154#define FLAG_EXPORT 2 /* protected by sysfs_lock */
155#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
156#define FLAG_ACTIVE_LOW 6 /* value has active low */
157#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
158#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
159#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
160#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
161
162 /* Connection label */
163 const char *label;
164 /* Name of the GPIO */
165 const char *name;
166};
167
168int gpiod_request(struct gpio_desc *desc, const char *label);
169void gpiod_free(struct gpio_desc *desc);
170int gpiod_hog(struct gpio_desc *desc, const char *name,
171 unsigned long lflags, enum gpiod_flags dflags);
172
173/*
174 * Return the GPIO number of the passed descriptor relative to its chip
175 */
176static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
177{
178 return desc - &desc->gdev->descs[0];
179}
180
181/* With descriptor prefix */
182
183#define gpiod_emerg(desc, fmt, ...) \
184 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
185 ##__VA_ARGS__)
186#define gpiod_crit(desc, fmt, ...) \
187 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
188 ##__VA_ARGS__)
189#define gpiod_err(desc, fmt, ...) \
190 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
191 ##__VA_ARGS__)
192#define gpiod_warn(desc, fmt, ...) \
193 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
194 ##__VA_ARGS__)
195#define gpiod_info(desc, fmt, ...) \
196 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
197 ##__VA_ARGS__)
198#define gpiod_dbg(desc, fmt, ...) \
199 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
200 ##__VA_ARGS__)
201
202/* With chip prefix */
203
204#define chip_emerg(chip, fmt, ...) \
205 dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
206#define chip_crit(chip, fmt, ...) \
207 dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
208#define chip_err(chip, fmt, ...) \
209 dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
210#define chip_warn(chip, fmt, ...) \
211 dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
212#define chip_info(chip, fmt, ...) \
213 dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
214#define chip_dbg(chip, fmt, ...) \
215 dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
216
217#ifdef CONFIG_GPIO_SYSFS
218
219int gpiochip_sysfs_register(struct gpio_device *gdev);
220void gpiochip_sysfs_unregister(struct gpio_device *gdev);
221
222#else
223
224static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
225{
226 return 0;
227}
228
229static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
230{
231}
232
233#endif /* CONFIG_GPIO_SYSFS */
234
235#endif /* GPIOLIB_H */
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 */