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/gpio/driver.h>
13 #include <linux/gpio/consumer.h> /* for enum gpiod_flags */
14 #include <linux/err.h>
15 #include <linux/device.h>
16 #include <linux/module.h>
17 #include <linux/cdev.h>
18
19 #define GPIOCHIP_NAME "gpiochip"
20
21 /**
22 * struct gpio_device - internal state container for GPIO devices
23 * @id: numerical ID number for the GPIO chip
24 * @dev: the GPIO device struct
25 * @chrdev: character device for the GPIO device
26 * @mockdev: class device used by the deprecated sysfs interface (may be
27 * NULL)
28 * @owner: helps prevent removal of modules exporting active GPIOs
29 * @chip: pointer to the corresponding gpiochip, holding static
30 * data for this device
31 * @descs: array of ngpio descriptors.
32 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
33 * of the @descs array.
34 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
35 * at device creation time.
36 * @label: a descriptive name for the GPIO device, such as the part number
37 * or name of the IP component in a System on Chip.
38 * @data: per-instance data assigned by the driver
39 * @list: links gpio_device:s together for traversal
40 * @notifier: used to notify subscribers about lines being requested, released
41 * or reconfigured
42 * @pin_ranges: range of pins served by the GPIO driver
43 *
44 * This state container holds most of the runtime variable data
45 * for a GPIO device and can hold references and live on after the
46 * GPIO chip has been removed, if it is still being used from
47 * userspace.
48 */
49 struct gpio_device {
50 int id;
51 struct device dev;
52 struct cdev chrdev;
53 struct device *mockdev;
54 struct module *owner;
55 struct gpio_chip *chip;
56 struct gpio_desc *descs;
57 int base;
58 u16 ngpio;
59 const char *label;
60 void *data;
61 struct list_head list;
62 struct blocking_notifier_head notifier;
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 /* gpio suffixes used for ACPI and device tree lookup */
76 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
77
78 /**
79 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
80 *
81 * @desc: Array of pointers to the GPIO descriptors
82 * @size: Number of elements in desc
83 * @chip: Parent GPIO chip
84 * @get_mask: Get mask used in fastpath
85 * @set_mask: Set mask used in fastpath
86 * @invert_mask: Invert mask used in fastpath
87 *
88 * This structure is attached to struct gpiod_descs obtained from
89 * gpiod_get_array() and can be passed back to get/set array functions in order
90 * to activate fast processing path if applicable.
91 */
92 struct gpio_array {
93 struct gpio_desc **desc;
94 unsigned int size;
95 struct gpio_chip *chip;
96 unsigned long *get_mask;
97 unsigned long *set_mask;
98 unsigned long invert_mask[];
99 };
100
101 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
102 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
103 unsigned int array_size,
104 struct gpio_desc **desc_array,
105 struct gpio_array *array_info,
106 unsigned long *value_bitmap);
107 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
108 unsigned int array_size,
109 struct gpio_desc **desc_array,
110 struct gpio_array *array_info,
111 unsigned long *value_bitmap);
112
113 extern spinlock_t gpio_lock;
114 extern struct list_head gpio_devices;
115
116
117 /**
118 * struct gpio_desc - Opaque descriptor for a GPIO
119 *
120 * @gdev: Pointer to the parent GPIO device
121 * @flags: Binary descriptor flags
122 * @label: Name of the consumer
123 * @name: Line name
124 * @hog: Pointer to the device node that hogs this line (if any)
125 * @debounce_period_us: Debounce period in microseconds
126 *
127 * These are obtained using gpiod_get() and are preferable to the old
128 * integer-based handles.
129 *
130 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
131 * valid until the GPIO is released.
132 */
133 struct gpio_desc {
134 struct gpio_device *gdev;
135 unsigned long flags;
136 /* flag symbols are bit numbers */
137 #define FLAG_REQUESTED 0
138 #define FLAG_IS_OUT 1
139 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
140 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
141 #define FLAG_ACTIVE_LOW 6 /* value has active low */
142 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
143 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
144 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
145 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
146 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
147 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
148 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
149 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
150 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
151 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
152 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
153 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
154
155 /* Connection label */
156 const char *label;
157 /* Name of the GPIO */
158 const char *name;
159 #ifdef CONFIG_OF_DYNAMIC
160 struct device_node *hog;
161 #endif
162 #ifdef CONFIG_GPIO_CDEV
163 /* debounce period in microseconds */
164 unsigned int debounce_period_us;
165 #endif
166 };
167
168 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
169
170 int gpiod_request(struct gpio_desc *desc, const char *label);
171 void gpiod_free(struct gpio_desc *desc);
172
gpiod_request_user(struct gpio_desc * desc,const char * label)173 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
174 {
175 int ret;
176
177 ret = gpiod_request(desc, label);
178 if (ret == -EPROBE_DEFER)
179 ret = -ENODEV;
180
181 return ret;
182 }
183
184 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
185 unsigned long lflags, enum gpiod_flags dflags);
186 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
187 int gpiod_hog(struct gpio_desc *desc, const char *name,
188 unsigned long lflags, enum gpiod_flags dflags);
189
190 /*
191 * Return the GPIO number of the passed descriptor relative to its chip
192 */
gpio_chip_hwgpio(const struct gpio_desc * desc)193 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
194 {
195 return desc - &desc->gdev->descs[0];
196 }
197
198 /* With descriptor prefix */
199
200 #define gpiod_emerg(desc, fmt, ...) \
201 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
202 ##__VA_ARGS__)
203 #define gpiod_crit(desc, fmt, ...) \
204 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
205 ##__VA_ARGS__)
206 #define gpiod_err(desc, fmt, ...) \
207 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
208 ##__VA_ARGS__)
209 #define gpiod_warn(desc, fmt, ...) \
210 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
211 ##__VA_ARGS__)
212 #define gpiod_info(desc, fmt, ...) \
213 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
214 ##__VA_ARGS__)
215 #define gpiod_dbg(desc, fmt, ...) \
216 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
217 ##__VA_ARGS__)
218
219 /* With chip prefix */
220
221 #define chip_emerg(gc, fmt, ...) \
222 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
223 #define chip_crit(gc, fmt, ...) \
224 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
225 #define chip_err(gc, fmt, ...) \
226 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
227 #define chip_warn(gc, fmt, ...) \
228 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
229 #define chip_info(gc, fmt, ...) \
230 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
231 #define chip_dbg(gc, fmt, ...) \
232 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
233
234 #endif /* GPIOLIB_H */
235