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/spinlock.h>
20 #include <linux/string.h>
21 #include <linux/srcu.h>
22 #include <linux/workqueue.h>
23
24 #define GPIOCHIP_NAME "gpiochip"
25
26 struct fwnode_handle;
27
28 /**
29 * struct gpio_device - internal state container for GPIO devices
30 * @dev: the GPIO device struct
31 * @chrdev: character device for the GPIO device
32 * @id: numerical ID number for the GPIO chip
33 * @owner: helps prevent removal of modules exporting active GPIOs
34 * @chip: pointer to the corresponding gpiochip, holding static
35 * data for this device
36 * @descs: array of ngpio descriptors.
37 * @valid_mask: If not %NULL, holds bitmask of GPIOs which are valid to be
38 * used from the chip.
39 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users
40 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
41 * of the @descs array.
42 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
43 * implying that they cannot be used from atomic context
44 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
45 * at device creation time.
46 * @label: a descriptive name for the GPIO device, such as the part number
47 * or name of the IP component in a System on Chip.
48 * @data: per-instance data assigned by the driver
49 * @list: links gpio_device:s together for traversal
50 * @line_state_notifier: used to notify subscribers about lines being
51 * requested, released or reconfigured
52 * @line_state_lock: RW-spinlock protecting the line state notifier
53 * @line_state_wq: used to emit line state events from a separate thread in
54 * process context
55 * @device_notifier: used to notify character device wait queues about the GPIO
56 * device being unregistered
57 * @srcu: protects the pointer to the underlying GPIO chip
58 * @pin_ranges: range of pins served by the GPIO driver
59 *
60 * This state container holds most of the runtime variable data
61 * for a GPIO device and can hold references and live on after the
62 * GPIO chip has been removed, if it is still being used from
63 * userspace.
64 */
65 struct gpio_device {
66 struct device dev;
67 struct cdev chrdev;
68 int id;
69 struct module *owner;
70 struct gpio_chip __rcu *chip;
71 struct gpio_desc *descs;
72 unsigned long *valid_mask;
73 struct srcu_struct desc_srcu;
74 unsigned int base;
75 u16 ngpio;
76 bool can_sleep;
77 const char *label;
78 void *data;
79 struct list_head list;
80 struct raw_notifier_head line_state_notifier;
81 rwlock_t line_state_lock;
82 struct workqueue_struct *line_state_wq;
83 struct blocking_notifier_head device_notifier;
84 struct srcu_struct srcu;
85
86 #ifdef CONFIG_PINCTRL
87 /*
88 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
89 * describe the actual pin range which they serve in an SoC. This
90 * information would be used by pinctrl subsystem to configure
91 * corresponding pins for gpio usage.
92 */
93 struct list_head pin_ranges;
94 #endif
95 };
96
to_gpio_device(struct device * dev)97 static inline struct gpio_device *to_gpio_device(struct device *dev)
98 {
99 return container_of(dev, struct gpio_device, dev);
100 }
101
102 /* GPIO suffixes used for ACPI and device tree lookup */
103 extern const char *const gpio_suffixes[];
104
105 #define for_each_gpio_property_name(propname, con_id) \
106 for (const char * const *__suffixes = gpio_suffixes; \
107 *__suffixes && ({ \
108 const char *__gs = *__suffixes; \
109 \
110 if (con_id) \
111 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \
112 else \
113 strscpy(propname, __gs); \
114 1; \
115 }); \
116 __suffixes++)
117
118 /**
119 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
120 *
121 * @desc: Array of pointers to the GPIO descriptors
122 * @size: Number of elements in desc
123 * @gdev: Parent GPIO device
124 * @get_mask: Get mask used in fastpath
125 * @set_mask: Set mask used in fastpath
126 * @invert_mask: Invert mask used in fastpath
127 *
128 * This structure is attached to struct gpiod_descs obtained from
129 * gpiod_get_array() and can be passed back to get/set array functions in order
130 * to activate fast processing path if applicable.
131 */
132 struct gpio_array {
133 struct gpio_desc **desc;
134 unsigned int size;
135 struct gpio_device *gdev;
136 unsigned long *get_mask;
137 unsigned long *set_mask;
138 unsigned long invert_mask[];
139 };
140
141 #define for_each_gpio_desc(gc, desc) \
142 for (unsigned int __i = 0; \
143 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
144 __i++) \
145
146 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
147 for_each_gpio_desc(gc, desc) \
148 if (!test_bit(flag, &desc->flags)) {} else
149
150 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
151 unsigned int array_size,
152 struct gpio_desc **desc_array,
153 struct gpio_array *array_info,
154 unsigned long *value_bitmap);
155 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
156 unsigned int array_size,
157 struct gpio_desc **desc_array,
158 struct gpio_array *array_info,
159 unsigned long *value_bitmap);
160
161 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
162
163 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
164 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value);
165 int gpiod_direction_input_nonotify(struct gpio_desc *desc);
166
167 struct gpio_desc_label {
168 struct rcu_head rh;
169 char str[];
170 };
171
172 /**
173 * struct gpio_desc - Opaque descriptor for a GPIO
174 *
175 * @gdev: Pointer to the parent GPIO device
176 * @flags: Binary descriptor flags
177 * @label: Name of the consumer
178 * @name: Line name
179 * @hog: Pointer to the device node that hogs this line (if any)
180 * @debounce_period_us: Debounce period in microseconds
181 *
182 * These are obtained using gpiod_get() and are preferable to the old
183 * integer-based handles.
184 *
185 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
186 * valid until the GPIO is released.
187 */
188 struct gpio_desc {
189 struct gpio_device *gdev;
190 unsigned long flags;
191 /* flag symbols are bit numbers */
192 #define GPIOD_FLAG_REQUESTED 0 /* GPIO is in use */
193 #define GPIOD_FLAG_IS_OUT 1 /* GPIO is in output mode */
194 #define GPIOD_FLAG_EXPORT 2 /* GPIO is exported to user-space */
195 #define GPIOD_FLAG_SYSFS 3 /* GPIO is exported via /sys/class/gpio */
196 #define GPIOD_FLAG_ACTIVE_LOW 6 /* GPIO is active-low */
197 #define GPIOD_FLAG_OPEN_DRAIN 7 /* GPIO is open drain type */
198 #define GPIOD_FLAG_OPEN_SOURCE 8 /* GPIO is open source type */
199 #define GPIOD_FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
200 #define GPIOD_FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
201 #define GPIOD_FLAG_IS_HOGGED 11 /* GPIO is hogged */
202 #define GPIOD_FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
203 #define GPIOD_FLAG_PULL_UP 13 /* GPIO has pull up enabled */
204 #define GPIOD_FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
205 #define GPIOD_FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
206 #define GPIOD_FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
207 #define GPIOD_FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
208 #define GPIOD_FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
209 #define GPIOD_FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
210 #define GPIOD_FLAG_SHARED 20 /* GPIO is shared by multiple consumers */
211 #define GPIOD_FLAG_SHARED_PROXY 21 /* GPIO is a virtual proxy to a physically shared pin. */
212
213 /* Connection label */
214 struct gpio_desc_label __rcu *label;
215 /* Name of the GPIO */
216 const char *name;
217 #ifdef CONFIG_OF_DYNAMIC
218 struct device_node *hog;
219 #endif
220 #ifdef CONFIG_GPIO_CDEV
221 /* debounce period in microseconds */
222 unsigned int debounce_period_us;
223 #endif
224 };
225
226 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
227
228 struct gpio_chip_guard {
229 struct gpio_device *gdev;
230 struct gpio_chip *gc;
231 int idx;
232 };
233
234 DEFINE_CLASS(gpio_chip_guard,
235 struct gpio_chip_guard,
236 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
237 ({
238 struct gpio_chip_guard _guard;
239
240 _guard.gdev = desc->gdev;
241 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
242 _guard.gc = srcu_dereference(_guard.gdev->chip,
243 &_guard.gdev->srcu);
244
245 _guard;
246 }),
247 struct gpio_desc *desc)
248
249 int gpiod_request(struct gpio_desc *desc, const char *label);
250 int gpiod_request_commit(struct gpio_desc *desc, const char *label);
251 void gpiod_free(struct gpio_desc *desc);
252 void gpiod_free_commit(struct gpio_desc *desc);
253
gpiod_request_user(struct gpio_desc * desc,const char * label)254 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
255 {
256 int ret;
257
258 ret = gpiod_request(desc, label);
259 if (ret == -EPROBE_DEFER)
260 ret = -ENODEV;
261
262 return ret;
263 }
264
265 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
266 struct fwnode_handle *fwnode,
267 const char *con_id,
268 unsigned int idx,
269 enum gpiod_flags flags,
270 const char *label,
271 bool platform_lookup_allowed);
272
273 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config);
274 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
275 unsigned long lflags, enum gpiod_flags dflags);
276 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
277 int gpiod_hog(struct gpio_desc *desc, const char *name,
278 unsigned long lflags, enum gpiod_flags dflags);
279 int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode);
280 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
281 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
282 const char *gpiod_get_label(struct gpio_desc *desc);
283
284 /* With descriptor prefix */
285
286 #define __gpiod_pr(level, desc, fmt, ...) \
287 do { \
288 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
289 pr_##level("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
290 gpiod_get_label(desc) ?: "?", ##__VA_ARGS__); \
291 } \
292 } while (0)
293
294 #define gpiod_err(desc, fmt, ...) __gpiod_pr(err, desc, fmt, ##__VA_ARGS__)
295 #define gpiod_warn(desc, fmt, ...) __gpiod_pr(warn, desc, fmt, ##__VA_ARGS__)
296 #define gpiod_dbg(desc, fmt, ...) __gpiod_pr(debug, desc, fmt, ##__VA_ARGS__)
297
298 /* With chip prefix */
299
300 #define __gpiochip_pr(level, gc, fmt, ...) \
301 do { \
302 dev_##level(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__); \
303 } while (0)
304
305 #define gpiochip_err(gc, fmt, ...) __gpiochip_pr(err, gc, fmt, ##__VA_ARGS__)
306 #define gpiochip_warn(gc, fmt, ...) __gpiochip_pr(warn, gc, fmt, ##__VA_ARGS__)
307 #define gpiochip_info(gc, fmt, ...) __gpiochip_pr(info, gc, fmt, ##__VA_ARGS__)
308 #define gpiochip_dbg(gc, fmt, ...) __gpiochip_pr(dbg, gc, fmt, ##__VA_ARGS__)
309
310 #endif /* GPIOLIB_H */
311