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/srcu.h>
20 #include <linux/workqueue.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 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users
36 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
37 * of the @descs array.
38 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
39 * implying that they cannot be used from atomic context
40 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
41 * at device creation time.
42 * @label: a descriptive name for the GPIO device, such as the part number
43 * or name of the IP component in a System on Chip.
44 * @data: per-instance data assigned by the driver
45 * @list: links gpio_device:s together for traversal
46 * @line_state_notifier: used to notify subscribers about lines being
47 * requested, released or reconfigured
48 * @line_state_wq: used to emit line state events from a separate thread in
49 * process context
50 * @device_notifier: used to notify character device wait queues about the GPIO
51 * device being unregistered
52 * @srcu: protects the pointer to the underlying GPIO chip
53 * @pin_ranges: range of pins served by the GPIO driver
54 *
55 * This state container holds most of the runtime variable data
56 * for a GPIO device and can hold references and live on after the
57 * GPIO chip has been removed, if it is still being used from
58 * userspace.
59 */
60 struct gpio_device {
61 struct device dev;
62 struct cdev chrdev;
63 int id;
64 struct device *mockdev;
65 struct module *owner;
66 struct gpio_chip __rcu *chip;
67 struct gpio_desc *descs;
68 struct srcu_struct desc_srcu;
69 unsigned int base;
70 u16 ngpio;
71 bool can_sleep;
72 const char *label;
73 void *data;
74 struct list_head list;
75 struct atomic_notifier_head line_state_notifier;
76 struct workqueue_struct *line_state_wq;
77 struct blocking_notifier_head device_notifier;
78 struct srcu_struct srcu;
79
80 #ifdef CONFIG_PINCTRL
81 /*
82 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
83 * describe the actual pin range which they serve in an SoC. This
84 * information would be used by pinctrl subsystem to configure
85 * corresponding pins for gpio usage.
86 */
87 struct list_head pin_ranges;
88 #endif
89 };
90
to_gpio_device(struct device * dev)91 static inline struct gpio_device *to_gpio_device(struct device *dev)
92 {
93 return container_of(dev, struct gpio_device, dev);
94 }
95
96 /* GPIO suffixes used for ACPI and device tree lookup */
97 extern const char *const gpio_suffixes[];
98
99 #define for_each_gpio_property_name(propname, con_id) \
100 for (const char * const *__suffixes = gpio_suffixes; \
101 *__suffixes && ({ \
102 const char *__gs = *__suffixes; \
103 \
104 if (con_id) \
105 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \
106 else \
107 snprintf(propname, sizeof(propname), "%s", __gs); \
108 1; \
109 }); \
110 __suffixes++)
111
112 /**
113 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
114 *
115 * @desc: Array of pointers to the GPIO descriptors
116 * @size: Number of elements in desc
117 * @chip: Parent GPIO chip
118 * @get_mask: Get mask used in fastpath
119 * @set_mask: Set mask used in fastpath
120 * @invert_mask: Invert mask used in fastpath
121 *
122 * This structure is attached to struct gpiod_descs obtained from
123 * gpiod_get_array() and can be passed back to get/set array functions in order
124 * to activate fast processing path if applicable.
125 */
126 struct gpio_array {
127 struct gpio_desc **desc;
128 unsigned int size;
129 struct gpio_chip *chip;
130 unsigned long *get_mask;
131 unsigned long *set_mask;
132 unsigned long invert_mask[];
133 };
134
135 #define for_each_gpio_desc(gc, desc) \
136 for (unsigned int __i = 0; \
137 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
138 __i++) \
139
140 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
141 for_each_gpio_desc(gc, desc) \
142 if (!test_bit(flag, &desc->flags)) {} else
143
144 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
145 unsigned int array_size,
146 struct gpio_desc **desc_array,
147 struct gpio_array *array_info,
148 unsigned long *value_bitmap);
149 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
150 unsigned int array_size,
151 struct gpio_desc **desc_array,
152 struct gpio_array *array_info,
153 unsigned long *value_bitmap);
154
155 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
156
157 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
158 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value);
159 int gpiod_direction_input_nonotify(struct gpio_desc *desc);
160
161 struct gpio_desc_label {
162 struct rcu_head rh;
163 char str[];
164 };
165
166 /**
167 * struct gpio_desc - Opaque descriptor for a GPIO
168 *
169 * @gdev: Pointer to the parent GPIO device
170 * @flags: Binary descriptor flags
171 * @label: Name of the consumer
172 * @name: Line name
173 * @hog: Pointer to the device node that hogs this line (if any)
174 * @debounce_period_us: Debounce period in microseconds
175 *
176 * These are obtained using gpiod_get() and are preferable to the old
177 * integer-based handles.
178 *
179 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
180 * valid until the GPIO is released.
181 */
182 struct gpio_desc {
183 struct gpio_device *gdev;
184 unsigned long flags;
185 /* flag symbols are bit numbers */
186 #define FLAG_REQUESTED 0
187 #define FLAG_IS_OUT 1
188 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
189 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
190 #define FLAG_ACTIVE_LOW 6 /* value has active low */
191 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
192 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
193 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
194 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
195 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
196 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
197 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
198 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
199 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
200 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
201 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
202 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
203 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
204
205 /* Connection label */
206 struct gpio_desc_label __rcu *label;
207 /* Name of the GPIO */
208 const char *name;
209 #ifdef CONFIG_OF_DYNAMIC
210 struct device_node *hog;
211 #endif
212 #ifdef CONFIG_GPIO_CDEV
213 /* debounce period in microseconds */
214 unsigned int debounce_period_us;
215 #endif
216 };
217
218 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
219
220 struct gpio_chip_guard {
221 struct gpio_device *gdev;
222 struct gpio_chip *gc;
223 int idx;
224 };
225
226 DEFINE_CLASS(gpio_chip_guard,
227 struct gpio_chip_guard,
228 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
229 ({
230 struct gpio_chip_guard _guard;
231
232 _guard.gdev = desc->gdev;
233 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
234 _guard.gc = srcu_dereference(_guard.gdev->chip,
235 &_guard.gdev->srcu);
236
237 _guard;
238 }),
239 struct gpio_desc *desc)
240
241 int gpiod_request(struct gpio_desc *desc, const char *label);
242 void gpiod_free(struct gpio_desc *desc);
243
gpiod_request_user(struct gpio_desc * desc,const char * label)244 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
245 {
246 int ret;
247
248 ret = gpiod_request(desc, label);
249 if (ret == -EPROBE_DEFER)
250 ret = -ENODEV;
251
252 return ret;
253 }
254
255 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
256 struct fwnode_handle *fwnode,
257 const char *con_id,
258 unsigned int idx,
259 enum gpiod_flags flags,
260 const char *label,
261 bool platform_lookup_allowed);
262
263 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config);
264 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
265 unsigned long lflags, enum gpiod_flags dflags);
266 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
267 int gpiod_hog(struct gpio_desc *desc, const char *name,
268 unsigned long lflags, enum gpiod_flags dflags);
269 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
270 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
271 const char *gpiod_get_label(struct gpio_desc *desc);
272
273 /*
274 * Return the GPIO number of the passed descriptor relative to its chip
275 */
gpio_chip_hwgpio(const struct gpio_desc * desc)276 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
277 {
278 return desc - &desc->gdev->descs[0];
279 }
280
281 /* With descriptor prefix */
282
283 #define gpiod_err(desc, fmt, ...) \
284 do { \
285 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
286 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
287 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
288 } \
289 } while (0)
290
291 #define gpiod_warn(desc, fmt, ...) \
292 do { \
293 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
294 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
295 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
296 } \
297 } while (0)
298
299 #define gpiod_dbg(desc, fmt, ...) \
300 do { \
301 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
302 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
303 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
304 } \
305 } while (0)
306
307 /* With chip prefix */
308
309 #define chip_err(gc, fmt, ...) \
310 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
311 #define chip_warn(gc, fmt, ...) \
312 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
313 #define chip_info(gc, fmt, ...) \
314 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
315 #define chip_dbg(gc, fmt, ...) \
316 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
317
318 #endif /* GPIOLIB_H */
319