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 #include <linux/rwsem.h>
19
20 #define GPIOCHIP_NAME "gpiochip"
21
22 /**
23 * struct gpio_device - internal state container for GPIO devices
24 * @id: numerical ID number for the GPIO chip
25 * @dev: the GPIO device struct
26 * @chrdev: character device for the GPIO device
27 * @mockdev: class device used by the deprecated sysfs interface (may be
28 * NULL)
29 * @owner: helps prevent removal of modules exporting active GPIOs
30 * @chip: pointer to the corresponding gpiochip, holding static
31 * data for this device
32 * @descs: array of ngpio descriptors.
33 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
34 * of the @descs array.
35 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
36 * at device creation time.
37 * @label: a descriptive name for the GPIO device, such as the part number
38 * or name of the IP component in a System on Chip.
39 * @data: per-instance data assigned by the driver
40 * @list: links gpio_device:s together for traversal
41 * @notifier: used to notify subscribers about lines being requested, released
42 * or reconfigured
43 * @sem: protects the structure from a NULL-pointer dereference of @chip by
44 * user-space operations when the device gets unregistered during
45 * a hot-unplug event
46 * @pin_ranges: range of pins served by the GPIO driver
47 *
48 * This state container holds most of the runtime variable data
49 * for a GPIO device and can hold references and live on after the
50 * GPIO chip has been removed, if it is still being used from
51 * userspace.
52 */
53 struct gpio_device {
54 int id;
55 struct device dev;
56 struct cdev chrdev;
57 struct device *mockdev;
58 struct module *owner;
59 struct gpio_chip *chip;
60 struct gpio_desc *descs;
61 int base;
62 u16 ngpio;
63 const char *label;
64 void *data;
65 struct list_head list;
66 struct blocking_notifier_head notifier;
67 struct rw_semaphore sem;
68
69 #ifdef CONFIG_PINCTRL
70 /*
71 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
72 * describe the actual pin range which they serve in an SoC. This
73 * information would be used by pinctrl subsystem to configure
74 * corresponding pins for gpio usage.
75 */
76 struct list_head pin_ranges;
77 #endif
78 };
79
80 /* gpio suffixes used for ACPI and device tree lookup */
81 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
82
83 /**
84 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
85 *
86 * @desc: Array of pointers to the GPIO descriptors
87 * @size: Number of elements in desc
88 * @chip: Parent GPIO chip
89 * @get_mask: Get mask used in fastpath
90 * @set_mask: Set mask used in fastpath
91 * @invert_mask: Invert mask used in fastpath
92 *
93 * This structure is attached to struct gpiod_descs obtained from
94 * gpiod_get_array() and can be passed back to get/set array functions in order
95 * to activate fast processing path if applicable.
96 */
97 struct gpio_array {
98 struct gpio_desc **desc;
99 unsigned int size;
100 struct gpio_chip *chip;
101 unsigned long *get_mask;
102 unsigned long *set_mask;
103 unsigned long invert_mask[];
104 };
105
106 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
107
108 #define for_each_gpio_desc(gc, desc) \
109 for (unsigned int __i = 0; \
110 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
111 __i++) \
112
113 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
114 for_each_gpio_desc(gc, desc) \
115 if (!test_bit(flag, &desc->flags)) {} else
116
117 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
118 unsigned int array_size,
119 struct gpio_desc **desc_array,
120 struct gpio_array *array_info,
121 unsigned long *value_bitmap);
122 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
123 unsigned int array_size,
124 struct gpio_desc **desc_array,
125 struct gpio_array *array_info,
126 unsigned long *value_bitmap);
127
128 extern spinlock_t gpio_lock;
129 extern struct list_head gpio_devices;
130
131
132 /**
133 * struct gpio_desc - Opaque descriptor for a GPIO
134 *
135 * @gdev: Pointer to the parent GPIO device
136 * @flags: Binary descriptor flags
137 * @label: Name of the consumer
138 * @name: Line name
139 * @hog: Pointer to the device node that hogs this line (if any)
140 * @debounce_period_us: Debounce period in microseconds
141 *
142 * These are obtained using gpiod_get() and are preferable to the old
143 * integer-based handles.
144 *
145 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
146 * valid until the GPIO is released.
147 */
148 struct 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_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
161 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
162 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
163 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
164 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
165 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
166 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
167 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
168 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
169 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
170
171 /* Connection label */
172 const char *label;
173 /* Name of the GPIO */
174 const char *name;
175 #ifdef CONFIG_OF_DYNAMIC
176 struct device_node *hog;
177 #endif
178 #ifdef CONFIG_GPIO_CDEV
179 /* debounce period in microseconds */
180 unsigned int debounce_period_us;
181 #endif
182 };
183
184 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
185
186 int gpiod_request(struct gpio_desc *desc, const char *label);
187 void gpiod_free(struct gpio_desc *desc);
188
gpiod_request_user(struct gpio_desc * desc,const char * label)189 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
190 {
191 int ret;
192
193 ret = gpiod_request(desc, label);
194 if (ret == -EPROBE_DEFER)
195 ret = -ENODEV;
196
197 return ret;
198 }
199
200 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
201 unsigned long lflags, enum gpiod_flags dflags);
202 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
203 int gpiod_hog(struct gpio_desc *desc, const char *name,
204 unsigned long lflags, enum gpiod_flags dflags);
205
206 /*
207 * Return the GPIO number of the passed descriptor relative to its chip
208 */
gpio_chip_hwgpio(const struct gpio_desc * desc)209 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
210 {
211 return desc - &desc->gdev->descs[0];
212 }
213
214 /* With descriptor prefix */
215
216 #define gpiod_emerg(desc, fmt, ...) \
217 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
218 ##__VA_ARGS__)
219 #define gpiod_crit(desc, fmt, ...) \
220 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
221 ##__VA_ARGS__)
222 #define gpiod_err(desc, fmt, ...) \
223 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
224 ##__VA_ARGS__)
225 #define gpiod_warn(desc, fmt, ...) \
226 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
227 ##__VA_ARGS__)
228 #define gpiod_info(desc, fmt, ...) \
229 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
230 ##__VA_ARGS__)
231 #define gpiod_dbg(desc, fmt, ...) \
232 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
233 ##__VA_ARGS__)
234
235 /* With chip prefix */
236
237 #define chip_emerg(gc, fmt, ...) \
238 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
239 #define chip_crit(gc, fmt, ...) \
240 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
241 #define chip_err(gc, fmt, ...) \
242 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
243 #define chip_warn(gc, fmt, ...) \
244 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
245 #define chip_info(gc, fmt, ...) \
246 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
247 #define chip_dbg(gc, fmt, ...) \
248 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
249
250 #endif /* GPIOLIB_H */
251