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
21 #define GPIOCHIP_NAME "gpiochip"
22
23 /**
24 * struct gpio_device - internal state container for GPIO devices
25 * @dev: the GPIO device struct
26 * @chrdev: character device for the GPIO device
27 * @id: numerical ID number for the GPIO chip
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 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users
35 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
36 * of the @descs array.
37 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
38 * implying that they cannot be used from atomic context
39 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
40 * at device creation time.
41 * @label: a descriptive name for the GPIO device, such as the part number
42 * or name of the IP component in a System on Chip.
43 * @data: per-instance data assigned by the driver
44 * @list: links gpio_device:s together for traversal
45 * @line_state_notifier: used to notify subscribers about lines being
46 * requested, released or reconfigured
47 * @device_notifier: used to notify character device wait queues about the GPIO
48 * device being unregistered
49 * @srcu: protects the pointer to the underlying GPIO chip
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 __rcu *chip;
64 struct gpio_desc *descs;
65 struct srcu_struct desc_srcu;
66 unsigned int base;
67 u16 ngpio;
68 bool can_sleep;
69 const char *label;
70 void *data;
71 struct list_head list;
72 struct blocking_notifier_head line_state_notifier;
73 struct blocking_notifier_head device_notifier;
74 struct srcu_struct srcu;
75
76 #ifdef CONFIG_PINCTRL
77 /*
78 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
79 * describe the actual pin range which they serve in an SoC. This
80 * information would be used by pinctrl subsystem to configure
81 * corresponding pins for gpio usage.
82 */
83 struct list_head pin_ranges;
84 #endif
85 };
86
to_gpio_device(struct device * dev)87 static inline struct gpio_device *to_gpio_device(struct device *dev)
88 {
89 return container_of(dev, struct gpio_device, dev);
90 }
91
92 /* gpio suffixes used for ACPI and device tree lookup */
93 extern const char *const gpio_suffixes[];
94 extern const size_t gpio_suffix_count;
95
96 /**
97 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
98 *
99 * @desc: Array of pointers to the GPIO descriptors
100 * @size: Number of elements in desc
101 * @chip: Parent GPIO chip
102 * @get_mask: Get mask used in fastpath
103 * @set_mask: Set mask used in fastpath
104 * @invert_mask: Invert mask used in fastpath
105 *
106 * This structure is attached to struct gpiod_descs obtained from
107 * gpiod_get_array() and can be passed back to get/set array functions in order
108 * to activate fast processing path if applicable.
109 */
110 struct gpio_array {
111 struct gpio_desc **desc;
112 unsigned int size;
113 struct gpio_chip *chip;
114 unsigned long *get_mask;
115 unsigned long *set_mask;
116 unsigned long invert_mask[];
117 };
118
119 #define for_each_gpio_desc(gc, desc) \
120 for (unsigned int __i = 0; \
121 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
122 __i++) \
123
124 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
125 for_each_gpio_desc(gc, desc) \
126 if (!test_bit(flag, &desc->flags)) {} else
127
128 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
129 unsigned int array_size,
130 struct gpio_desc **desc_array,
131 struct gpio_array *array_info,
132 unsigned long *value_bitmap);
133 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
134 unsigned int array_size,
135 struct gpio_desc **desc_array,
136 struct gpio_array *array_info,
137 unsigned long *value_bitmap);
138
139 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
140
141 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
142
143 struct gpio_desc_label {
144 struct rcu_head rh;
145 char str[];
146 };
147
148 /**
149 * struct gpio_desc - Opaque descriptor for a GPIO
150 *
151 * @gdev: Pointer to the parent GPIO device
152 * @flags: Binary descriptor flags
153 * @label: Name of the consumer
154 * @name: Line name
155 * @hog: Pointer to the device node that hogs this line (if any)
156 *
157 * These are obtained using gpiod_get() and are preferable to the old
158 * integer-based handles.
159 *
160 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
161 * valid until the GPIO is released.
162 */
163 struct gpio_desc {
164 struct gpio_device *gdev;
165 unsigned long flags;
166 /* flag symbols are bit numbers */
167 #define FLAG_REQUESTED 0
168 #define FLAG_IS_OUT 1
169 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
170 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
171 #define FLAG_ACTIVE_LOW 6 /* value has active low */
172 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
173 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
174 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
175 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
176 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
177 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
178 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
179 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
180 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
181 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
182 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
183 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
184 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
185
186 /* Connection label */
187 struct gpio_desc_label __rcu *label;
188 /* Name of the GPIO */
189 const char *name;
190 #ifdef CONFIG_OF_DYNAMIC
191 struct device_node *hog;
192 #endif
193 };
194
195 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
196
197 struct gpio_chip_guard {
198 struct gpio_device *gdev;
199 struct gpio_chip *gc;
200 int idx;
201 };
202
203 DEFINE_CLASS(gpio_chip_guard,
204 struct gpio_chip_guard,
205 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
206 ({
207 struct gpio_chip_guard _guard;
208
209 _guard.gdev = desc->gdev;
210 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
211 _guard.gc = srcu_dereference(_guard.gdev->chip,
212 &_guard.gdev->srcu);
213
214 _guard;
215 }),
216 struct gpio_desc *desc)
217
218 int gpiod_request(struct gpio_desc *desc, const char *label);
219 void gpiod_free(struct gpio_desc *desc);
220
gpiod_request_user(struct gpio_desc * desc,const char * label)221 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
222 {
223 int ret;
224
225 ret = gpiod_request(desc, label);
226 if (ret == -EPROBE_DEFER)
227 ret = -ENODEV;
228
229 return ret;
230 }
231
232 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
233 struct fwnode_handle *fwnode,
234 const char *con_id,
235 unsigned int idx,
236 enum gpiod_flags flags,
237 const char *label,
238 bool platform_lookup_allowed);
239
240 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
241 unsigned long lflags, enum gpiod_flags dflags);
242 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
243 int gpiod_hog(struct gpio_desc *desc, const char *name,
244 unsigned long lflags, enum gpiod_flags dflags);
245 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
246 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
247 const char *gpiod_get_label(struct gpio_desc *desc);
248
249 /*
250 * Return the GPIO number of the passed descriptor relative to its chip
251 */
gpio_chip_hwgpio(const struct gpio_desc * desc)252 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
253 {
254 return desc - &desc->gdev->descs[0];
255 }
256
257 /* With descriptor prefix */
258
259 #define gpiod_err(desc, fmt, ...) \
260 do { \
261 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
262 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
263 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
264 } \
265 } while (0)
266
267 #define gpiod_warn(desc, fmt, ...) \
268 do { \
269 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
270 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
271 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
272 } \
273 } while (0)
274
275 #define gpiod_dbg(desc, fmt, ...) \
276 do { \
277 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
278 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
279 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
280 } \
281 } while (0)
282
283 /* With chip prefix */
284
285 #define chip_err(gc, fmt, ...) \
286 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
287 #define chip_warn(gc, fmt, ...) \
288 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
289 #define chip_info(gc, fmt, ...) \
290 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
291 #define chip_dbg(gc, fmt, ...) \
292 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
293
294 #endif /* GPIOLIB_H */
295