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 #include <linux/android_kabi.h>
20
21 #define GPIOCHIP_NAME "gpiochip"
22
23 /**
24 * struct gpio_device - internal state container for GPIO devices
25 * @id: numerical ID number for the GPIO chip
26 * @dev: the GPIO device struct
27 * @chrdev: character device for the GPIO device
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 * @notifier: used to notify subscribers about lines being requested, released
43 * or reconfigured
44 * @sem: protects the structure from a NULL-pointer dereference of @chip by
45 * user-space operations when the device gets unregistered during
46 * a hot-unplug event
47 * @pin_ranges: range of pins served by the GPIO driver
48 *
49 * This state container holds most of the runtime variable data
50 * for a GPIO device and can hold references and live on after the
51 * GPIO chip has been removed, if it is still being used from
52 * userspace.
53 */
54 struct gpio_device {
55 int id;
56 struct device dev;
57 struct cdev chrdev;
58 struct device *mockdev;
59 struct module *owner;
60 struct gpio_chip *chip;
61 struct gpio_desc *descs;
62 int base;
63 u16 ngpio;
64 const char *label;
65 void *data;
66 struct list_head list;
67 struct blocking_notifier_head notifier;
68 struct rw_semaphore sem;
69
70 #ifdef CONFIG_PINCTRL
71 /*
72 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
73 * describe the actual pin range which they serve in an SoC. This
74 * information would be used by pinctrl subsystem to configure
75 * corresponding pins for gpio usage.
76 */
77 struct list_head pin_ranges;
78 #endif
79 ANDROID_KABI_RESERVE(1);
80 };
81
82 /* gpio suffixes used for ACPI and device tree lookup */
83 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
84
85 /**
86 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
87 *
88 * @desc: Array of pointers to the GPIO descriptors
89 * @size: Number of elements in desc
90 * @chip: Parent GPIO chip
91 * @get_mask: Get mask used in fastpath
92 * @set_mask: Set mask used in fastpath
93 * @invert_mask: Invert mask used in fastpath
94 *
95 * This structure is attached to struct gpiod_descs obtained from
96 * gpiod_get_array() and can be passed back to get/set array functions in order
97 * to activate fast processing path if applicable.
98 */
99 struct gpio_array {
100 struct gpio_desc **desc;
101 unsigned int size;
102 struct gpio_chip *chip;
103 unsigned long *get_mask;
104 unsigned long *set_mask;
105 ANDROID_KABI_RESERVE(1);
106 unsigned long invert_mask[];
107 };
108
109 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
110
111 #define for_each_gpio_desc(gc, desc) \
112 for (unsigned int __i = 0; \
113 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
114 __i++) \
115
116 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
117 for_each_gpio_desc(gc, desc) \
118 if (!test_bit(flag, &desc->flags)) {} else
119
120 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
121 unsigned int array_size,
122 struct gpio_desc **desc_array,
123 struct gpio_array *array_info,
124 unsigned long *value_bitmap);
125 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
126 unsigned int array_size,
127 struct gpio_desc **desc_array,
128 struct gpio_array *array_info,
129 unsigned long *value_bitmap);
130
131 extern spinlock_t gpio_lock;
132 extern struct list_head gpio_devices;
133
134
135 /**
136 * struct gpio_desc - Opaque descriptor for a GPIO
137 *
138 * @gdev: Pointer to the parent GPIO device
139 * @flags: Binary descriptor flags
140 * @label: Name of the consumer
141 * @name: Line name
142 * @hog: Pointer to the device node that hogs this line (if any)
143 * @debounce_period_us: Debounce period in microseconds
144 *
145 * These are obtained using gpiod_get() and are preferable to the old
146 * integer-based handles.
147 *
148 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
149 * valid until the GPIO is released.
150 */
151 struct gpio_desc {
152 struct gpio_device *gdev;
153 unsigned long flags;
154 /* flag symbols are bit numbers */
155 #define FLAG_REQUESTED 0
156 #define FLAG_IS_OUT 1
157 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
158 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
159 #define FLAG_ACTIVE_LOW 6 /* value has active low */
160 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
161 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
162 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
163 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
164 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
165 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
166 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
167 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
168 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
169 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
170 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
171 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
172 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
173
174 /* Connection label */
175 const char *label;
176 /* Name of the GPIO */
177 const char *name;
178 #ifdef CONFIG_OF_DYNAMIC
179 struct device_node *hog;
180 #endif
181 #ifdef CONFIG_GPIO_CDEV
182 /* debounce period in microseconds */
183 unsigned int debounce_period_us;
184 #endif
185 ANDROID_KABI_RESERVE(1);
186 };
187
188 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
189
190 int gpiod_request(struct gpio_desc *desc, const char *label);
191 void gpiod_free(struct gpio_desc *desc);
192
gpiod_request_user(struct gpio_desc * desc,const char * label)193 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
194 {
195 int ret;
196
197 ret = gpiod_request(desc, label);
198 if (ret == -EPROBE_DEFER)
199 ret = -ENODEV;
200
201 return ret;
202 }
203
204 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
205 unsigned long lflags, enum gpiod_flags dflags);
206 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
207 int gpiod_hog(struct gpio_desc *desc, const char *name,
208 unsigned long lflags, enum gpiod_flags dflags);
209
210 /*
211 * Return the GPIO number of the passed descriptor relative to its chip
212 */
gpio_chip_hwgpio(const struct gpio_desc * desc)213 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
214 {
215 return desc - &desc->gdev->descs[0];
216 }
217
218 /* With descriptor prefix */
219
220 #define gpiod_emerg(desc, fmt, ...) \
221 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
222 ##__VA_ARGS__)
223 #define gpiod_crit(desc, fmt, ...) \
224 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
225 ##__VA_ARGS__)
226 #define gpiod_err(desc, fmt, ...) \
227 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
228 ##__VA_ARGS__)
229 #define gpiod_warn(desc, fmt, ...) \
230 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
231 ##__VA_ARGS__)
232 #define gpiod_info(desc, fmt, ...) \
233 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
234 ##__VA_ARGS__)
235 #define gpiod_dbg(desc, fmt, ...) \
236 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
237 ##__VA_ARGS__)
238
239 /* With chip prefix */
240
241 #define chip_emerg(gc, fmt, ...) \
242 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
243 #define chip_crit(gc, fmt, ...) \
244 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
245 #define chip_err(gc, fmt, ...) \
246 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
247 #define chip_warn(gc, fmt, ...) \
248 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
249 #define chip_info(gc, fmt, ...) \
250 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
251 #define chip_dbg(gc, fmt, ...) \
252 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
253
254 #endif /* GPIOLIB_H */
255