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/rwsem.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 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
37 * at device creation time.
38 * @label: a descriptive name for the GPIO device, such as the part number
39 * or name of the IP component in a System on Chip.
40 * @data: per-instance data assigned by the driver
41 * @list: links gpio_device:s together for traversal
42 * @line_state_notifier: used to notify subscribers about lines being
43 * requested, released or reconfigured
44 * @device_notifier: used to notify character device wait queues about the GPIO
45 * device being unregistered
46 * @sem: protects the structure from a NULL-pointer dereference of @chip by
47 * user-space operations when the device gets unregistered during
48 * a hot-unplug event
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 */
56 struct 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 *chip;
63 struct gpio_desc *descs;
64 int base;
65 u16 ngpio;
66 const char *label;
67 void *data;
68 struct list_head list;
69 struct blocking_notifier_head line_state_notifier;
70 struct blocking_notifier_head device_notifier;
71 struct rw_semaphore sem;
72
73 #ifdef CONFIG_PINCTRL
74 /*
75 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
76 * describe the actual pin range which they serve in an SoC. This
77 * information would be used by pinctrl subsystem to configure
78 * corresponding pins for gpio usage.
79 */
80 struct list_head pin_ranges;
81 #endif
82 };
83
to_gpio_device(struct device * dev)84 static inline struct gpio_device *to_gpio_device(struct device *dev)
85 {
86 return container_of(dev, struct gpio_device, dev);
87 }
88
gpio_device_get(struct gpio_device * gdev)89 static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev)
90 {
91 return to_gpio_device(get_device(&gdev->dev));
92 }
93
gpio_device_put(struct gpio_device * gdev)94 static inline void gpio_device_put(struct gpio_device *gdev)
95 {
96 put_device(&gdev->dev);
97 }
98
99 /* gpio suffixes used for ACPI and device tree lookup */
100 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
101
102 /**
103 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
104 *
105 * @desc: Array of pointers to the GPIO descriptors
106 * @size: Number of elements in desc
107 * @chip: Parent GPIO chip
108 * @get_mask: Get mask used in fastpath
109 * @set_mask: Set mask used in fastpath
110 * @invert_mask: Invert mask used in fastpath
111 *
112 * This structure is attached to struct gpiod_descs obtained from
113 * gpiod_get_array() and can be passed back to get/set array functions in order
114 * to activate fast processing path if applicable.
115 */
116 struct gpio_array {
117 struct gpio_desc **desc;
118 unsigned int size;
119 struct gpio_chip *chip;
120 unsigned long *get_mask;
121 unsigned long *set_mask;
122 unsigned long invert_mask[];
123 };
124
125 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
126
127 #define for_each_gpio_desc(gc, desc) \
128 for (unsigned int __i = 0; \
129 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
130 __i++) \
131
132 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
133 for_each_gpio_desc(gc, desc) \
134 if (!test_bit(flag, &desc->flags)) {} else
135
136 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
137 unsigned int array_size,
138 struct gpio_desc **desc_array,
139 struct gpio_array *array_info,
140 unsigned long *value_bitmap);
141 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
142 unsigned int array_size,
143 struct gpio_desc **desc_array,
144 struct gpio_array *array_info,
145 unsigned long *value_bitmap);
146
147 extern spinlock_t gpio_lock;
148 extern struct list_head gpio_devices;
149
150 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
151
152 /**
153 * struct gpio_desc - Opaque descriptor for a GPIO
154 *
155 * @gdev: Pointer to the parent GPIO device
156 * @flags: Binary descriptor flags
157 * @label: Name of the consumer
158 * @name: Line name
159 * @hog: Pointer to the device node that hogs this line (if any)
160 * @debounce_period_us: Debounce period in microseconds
161 *
162 * These are obtained using gpiod_get() and are preferable to the old
163 * integer-based handles.
164 *
165 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
166 * valid until the GPIO is released.
167 */
168 struct gpio_desc {
169 struct gpio_device *gdev;
170 unsigned long flags;
171 /* flag symbols are bit numbers */
172 #define FLAG_REQUESTED 0
173 #define FLAG_IS_OUT 1
174 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
175 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
176 #define FLAG_ACTIVE_LOW 6 /* value has active low */
177 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
178 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
179 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
180 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
181 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
182 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
183 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
184 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
185 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
186 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
187 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
188 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
189 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
190
191 /* Connection label */
192 const char *label;
193 /* Name of the GPIO */
194 const char *name;
195 #ifdef CONFIG_OF_DYNAMIC
196 struct device_node *hog;
197 #endif
198 #ifdef CONFIG_GPIO_CDEV
199 /* debounce period in microseconds */
200 unsigned int debounce_period_us;
201 #endif
202 };
203
204 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
205
206 int gpiod_request(struct gpio_desc *desc, const char *label);
207 void gpiod_free(struct gpio_desc *desc);
208
gpiod_request_user(struct gpio_desc * desc,const char * label)209 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
210 {
211 int ret;
212
213 ret = gpiod_request(desc, label);
214 if (ret == -EPROBE_DEFER)
215 ret = -ENODEV;
216
217 return ret;
218 }
219
220 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
221 unsigned long lflags, enum gpiod_flags dflags);
222 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
223 int gpiod_hog(struct gpio_desc *desc, const char *name,
224 unsigned long lflags, enum gpiod_flags dflags);
225 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
226
227 /*
228 * Return the GPIO number of the passed descriptor relative to its chip
229 */
gpio_chip_hwgpio(const struct gpio_desc * desc)230 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
231 {
232 return desc - &desc->gdev->descs[0];
233 }
234
235 /* With descriptor prefix */
236
237 #define gpiod_emerg(desc, fmt, ...) \
238 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
239 ##__VA_ARGS__)
240 #define gpiod_crit(desc, fmt, ...) \
241 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
242 ##__VA_ARGS__)
243 #define gpiod_err(desc, fmt, ...) \
244 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
245 ##__VA_ARGS__)
246 #define gpiod_warn(desc, fmt, ...) \
247 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
248 ##__VA_ARGS__)
249 #define gpiod_info(desc, fmt, ...) \
250 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
251 ##__VA_ARGS__)
252 #define gpiod_dbg(desc, fmt, ...) \
253 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
254 ##__VA_ARGS__)
255
256 /* With chip prefix */
257
258 #define chip_emerg(gc, fmt, ...) \
259 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
260 #define chip_crit(gc, fmt, ...) \
261 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
262 #define chip_err(gc, fmt, ...) \
263 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
264 #define chip_warn(gc, fmt, ...) \
265 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
266 #define chip_info(gc, fmt, ...) \
267 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
268 #define chip_dbg(gc, fmt, ...) \
269 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
270
271 #endif /* GPIOLIB_H */
272
