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
89 /* gpio suffixes used for ACPI and device tree lookup */
90 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
91
92 /**
93 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
94 *
95 * @desc: Array of pointers to the GPIO descriptors
96 * @size: Number of elements in desc
97 * @chip: Parent GPIO chip
98 * @get_mask: Get mask used in fastpath
99 * @set_mask: Set mask used in fastpath
100 * @invert_mask: Invert mask used in fastpath
101 *
102 * This structure is attached to struct gpiod_descs obtained from
103 * gpiod_get_array() and can be passed back to get/set array functions in order
104 * to activate fast processing path if applicable.
105 */
106 struct gpio_array {
107 struct gpio_desc **desc;
108 unsigned int size;
109 struct gpio_chip *chip;
110 unsigned long *get_mask;
111 unsigned long *set_mask;
112 unsigned long invert_mask[];
113 };
114
115 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
116
117 #define for_each_gpio_desc(gc, desc) \
118 for (unsigned int __i = 0; \
119 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
120 __i++) \
121
122 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
123 for_each_gpio_desc(gc, desc) \
124 if (!test_bit(flag, &desc->flags)) {} else
125
126 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
127 unsigned int array_size,
128 struct gpio_desc **desc_array,
129 struct gpio_array *array_info,
130 unsigned long *value_bitmap);
131 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
132 unsigned int array_size,
133 struct gpio_desc **desc_array,
134 struct gpio_array *array_info,
135 unsigned long *value_bitmap);
136
137 extern spinlock_t gpio_lock;
138 extern struct list_head gpio_devices;
139
140 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
141
142 /**
143 * struct gpio_desc - Opaque descriptor for a GPIO
144 *
145 * @gdev: Pointer to the parent GPIO device
146 * @flags: Binary descriptor flags
147 * @label: Name of the consumer
148 * @name: Line name
149 * @hog: Pointer to the device node that hogs this line (if any)
150 * @debounce_period_us: Debounce period in microseconds
151 *
152 * These are obtained using gpiod_get() and are preferable to the old
153 * integer-based handles.
154 *
155 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
156 * valid until the GPIO is released.
157 */
158 struct gpio_desc {
159 struct gpio_device *gdev;
160 unsigned long flags;
161 /* flag symbols are bit numbers */
162 #define FLAG_REQUESTED 0
163 #define FLAG_IS_OUT 1
164 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
165 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
166 #define FLAG_ACTIVE_LOW 6 /* value has active low */
167 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
168 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
169 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
170 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
171 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
172 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
173 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
174 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
175 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
176 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
177 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
178 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
179 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
180
181 /* Connection label */
182 const char *label;
183 /* Name of the GPIO */
184 const char *name;
185 #ifdef CONFIG_OF_DYNAMIC
186 struct device_node *hog;
187 #endif
188 #ifdef CONFIG_GPIO_CDEV
189 /* debounce period in microseconds */
190 unsigned int debounce_period_us;
191 #endif
192 };
193
194 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
195
196 int gpiod_request(struct gpio_desc *desc, const char *label);
197 void gpiod_free(struct gpio_desc *desc);
198
gpiod_request_user(struct gpio_desc * desc,const char * label)199 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
200 {
201 int ret;
202
203 ret = gpiod_request(desc, label);
204 if (ret == -EPROBE_DEFER)
205 ret = -ENODEV;
206
207 return ret;
208 }
209
210 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
211 struct fwnode_handle *fwnode,
212 const char *con_id,
213 unsigned int idx,
214 enum gpiod_flags flags,
215 const char *label,
216 bool platform_lookup_allowed);
217
218 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
219 unsigned long lflags, enum gpiod_flags dflags);
220 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
221 int gpiod_hog(struct gpio_desc *desc, const char *name,
222 unsigned long lflags, enum gpiod_flags dflags);
223 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
224
225 /*
226 * Return the GPIO number of the passed descriptor relative to its chip
227 */
gpio_chip_hwgpio(const struct gpio_desc * desc)228 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
229 {
230 return desc - &desc->gdev->descs[0];
231 }
232
233 /* With descriptor prefix */
234
235 #define gpiod_emerg(desc, fmt, ...) \
236 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
237 ##__VA_ARGS__)
238 #define gpiod_crit(desc, fmt, ...) \
239 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
240 ##__VA_ARGS__)
241 #define gpiod_err(desc, fmt, ...) \
242 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
243 ##__VA_ARGS__)
244 #define gpiod_warn(desc, fmt, ...) \
245 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
246 ##__VA_ARGS__)
247 #define gpiod_info(desc, fmt, ...) \
248 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
249 ##__VA_ARGS__)
250 #define gpiod_dbg(desc, fmt, ...) \
251 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
252 ##__VA_ARGS__)
253
254 /* With chip prefix */
255
256 #define chip_emerg(gc, fmt, ...) \
257 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
258 #define chip_crit(gc, fmt, ...) \
259 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
260 #define chip_err(gc, fmt, ...) \
261 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
262 #define chip_warn(gc, fmt, ...) \
263 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
264 #define chip_info(gc, fmt, ...) \
265 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
266 #define chip_dbg(gc, fmt, ...) \
267 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
268
269 #endif /* GPIOLIB_H */
270