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 #include <linux/android_kabi.h>
21
22 #define GPIOCHIP_NAME "gpiochip"
23
24 /**
25 * struct gpio_device - internal state container for GPIO devices
26 * @dev: the GPIO device struct
27 * @chrdev: character device for the GPIO device
28 * @id: numerical ID number for the GPIO chip
29 * @mockdev: class device used by the deprecated sysfs interface (may be
30 * NULL)
31 * @owner: helps prevent removal of modules exporting active GPIOs
32 * @chip: pointer to the corresponding gpiochip, holding static
33 * data for this device
34 * @descs: array of ngpio descriptors.
35 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
36 * of the @descs array.
37 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
38 * at device creation time.
39 * @label: a descriptive name for the GPIO device, such as the part number
40 * or name of the IP component in a System on Chip.
41 * @data: per-instance data assigned by the driver
42 * @list: links gpio_device:s together for traversal
43 * @line_state_notifier: used to notify subscribers about lines being
44 * requested, released or reconfigured
45 * @device_notifier: used to notify character device wait queues about the GPIO
46 * device being unregistered
47 * @sem: protects the structure from a NULL-pointer dereference of @chip by
48 * user-space operations when the device gets unregistered during
49 * a hot-unplug event
50 * @pin_ranges: range of pins served by the GPIO driver
51 *
52 * This state container holds most of the runtime variable data
53 * for a GPIO device and can hold references and live on after the
54 * GPIO chip has been removed, if it is still being used from
55 * userspace.
56 */
57 struct gpio_device {
58 struct device dev;
59 struct cdev chrdev;
60 int id;
61 struct device *mockdev;
62 struct module *owner;
63 struct gpio_chip *chip;
64 struct gpio_desc *descs;
65 int base;
66 u16 ngpio;
67 const char *label;
68 void *data;
69 struct list_head list;
70 struct blocking_notifier_head line_state_notifier;
71 struct blocking_notifier_head device_notifier;
72 struct rw_semaphore sem;
73
74 #ifdef CONFIG_PINCTRL
75 /*
76 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
77 * describe the actual pin range which they serve in an SoC. This
78 * information would be used by pinctrl subsystem to configure
79 * corresponding pins for gpio usage.
80 */
81 struct list_head pin_ranges;
82 #endif
83 ANDROID_KABI_RESERVE(1);
84 };
85
to_gpio_device(struct device * dev)86 static inline struct gpio_device *to_gpio_device(struct device *dev)
87 {
88 return container_of(dev, struct gpio_device, dev);
89 }
90
91 /* gpio suffixes used for ACPI and device tree lookup */
92 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
93
94 /**
95 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
96 *
97 * @desc: Array of pointers to the GPIO descriptors
98 * @size: Number of elements in desc
99 * @chip: Parent GPIO chip
100 * @get_mask: Get mask used in fastpath
101 * @set_mask: Set mask used in fastpath
102 * @invert_mask: Invert mask used in fastpath
103 *
104 * This structure is attached to struct gpiod_descs obtained from
105 * gpiod_get_array() and can be passed back to get/set array functions in order
106 * to activate fast processing path if applicable.
107 */
108 struct gpio_array {
109 struct gpio_desc **desc;
110 unsigned int size;
111 struct gpio_chip *chip;
112 unsigned long *get_mask;
113 unsigned long *set_mask;
114 ANDROID_KABI_RESERVE(1);
115 unsigned long invert_mask[];
116 };
117
118 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
119
120 #define for_each_gpio_desc(gc, desc) \
121 for (unsigned int __i = 0; \
122 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
123 __i++) \
124
125 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
126 for_each_gpio_desc(gc, desc) \
127 if (!test_bit(flag, &desc->flags)) {} else
128
129 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
130 unsigned int array_size,
131 struct gpio_desc **desc_array,
132 struct gpio_array *array_info,
133 unsigned long *value_bitmap);
134 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
135 unsigned int array_size,
136 struct gpio_desc **desc_array,
137 struct gpio_array *array_info,
138 unsigned long *value_bitmap);
139
140 extern spinlock_t gpio_lock;
141 extern struct list_head gpio_devices;
142
143 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
144
145 /**
146 * struct gpio_desc - Opaque descriptor for a GPIO
147 *
148 * @gdev: Pointer to the parent GPIO device
149 * @flags: Binary descriptor flags
150 * @label: Name of the consumer
151 * @name: Line name
152 * @hog: Pointer to the device node that hogs this line (if any)
153 * @debounce_period_us: Debounce period in microseconds
154 *
155 * These are obtained using gpiod_get() and are preferable to the old
156 * integer-based handles.
157 *
158 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
159 * valid until the GPIO is released.
160 */
161 struct gpio_desc {
162 struct gpio_device *gdev;
163 unsigned long flags;
164 /* flag symbols are bit numbers */
165 #define FLAG_REQUESTED 0
166 #define FLAG_IS_OUT 1
167 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
168 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
169 #define FLAG_ACTIVE_LOW 6 /* value has active low */
170 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
171 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
172 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
173 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
174 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
175 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
176 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
177 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
178 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
179 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
180 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
181 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
182 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
183
184 /* Connection label */
185 const char *label;
186 /* Name of the GPIO */
187 const char *name;
188 #ifdef CONFIG_OF_DYNAMIC
189 struct device_node *hog;
190 #endif
191 #ifdef CONFIG_GPIO_CDEV
192 /* debounce period in microseconds */
193 unsigned int debounce_period_us;
194 #endif
195 ANDROID_KABI_RESERVE(1);
196 };
197
198 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
199
200 int gpiod_request(struct gpio_desc *desc, const char *label);
201 void gpiod_free(struct gpio_desc *desc);
202
gpiod_request_user(struct gpio_desc * desc,const char * label)203 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
204 {
205 int ret;
206
207 ret = gpiod_request(desc, label);
208 if (ret == -EPROBE_DEFER)
209 ret = -ENODEV;
210
211 return ret;
212 }
213
214 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
215 struct fwnode_handle *fwnode,
216 const char *con_id,
217 unsigned int idx,
218 enum gpiod_flags flags,
219 const char *label,
220 bool platform_lookup_allowed);
221
222 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
223 unsigned long lflags, enum gpiod_flags dflags);
224 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
225 int gpiod_hog(struct gpio_desc *desc, const char *name,
226 unsigned long lflags, enum gpiod_flags dflags);
227 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
228
229 /*
230 * Return the GPIO number of the passed descriptor relative to its chip
231 */
gpio_chip_hwgpio(const struct gpio_desc * desc)232 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
233 {
234 return desc - &desc->gdev->descs[0];
235 }
236
237 /* With descriptor prefix */
238
239 #define gpiod_emerg(desc, fmt, ...) \
240 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
241 ##__VA_ARGS__)
242 #define gpiod_crit(desc, fmt, ...) \
243 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
244 ##__VA_ARGS__)
245 #define gpiod_err(desc, fmt, ...) \
246 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
247 ##__VA_ARGS__)
248 #define gpiod_warn(desc, fmt, ...) \
249 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
250 ##__VA_ARGS__)
251 #define gpiod_info(desc, fmt, ...) \
252 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
253 ##__VA_ARGS__)
254 #define gpiod_dbg(desc, fmt, ...) \
255 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
256 ##__VA_ARGS__)
257
258 /* With chip prefix */
259
260 #define chip_emerg(gc, fmt, ...) \
261 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
262 #define chip_crit(gc, fmt, ...) \
263 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
264 #define chip_err(gc, fmt, ...) \
265 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
266 #define chip_warn(gc, fmt, ...) \
267 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
268 #define chip_info(gc, fmt, ...) \
269 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
270 #define chip_dbg(gc, fmt, ...) \
271 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
272
273 #endif /* GPIOLIB_H */
274