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
95 #define for_each_gpio_property_name(propname, con_id) \
96 for (const char * const *__suffixes = gpio_suffixes; \
97 *__suffixes && ({ \
98 const char *__gs = *__suffixes; \
99 \
100 if (con_id) \
101 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \
102 else \
103 snprintf(propname, sizeof(propname), "%s", __gs); \
104 1; \
105 }); \
106 __suffixes++)
107
108 /**
109 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
110 *
111 * @desc: Array of pointers to the GPIO descriptors
112 * @size: Number of elements in desc
113 * @chip: Parent GPIO chip
114 * @get_mask: Get mask used in fastpath
115 * @set_mask: Set mask used in fastpath
116 * @invert_mask: Invert mask used in fastpath
117 *
118 * This structure is attached to struct gpiod_descs obtained from
119 * gpiod_get_array() and can be passed back to get/set array functions in order
120 * to activate fast processing path if applicable.
121 */
122 struct gpio_array {
123 struct gpio_desc **desc;
124 unsigned int size;
125 struct gpio_chip *chip;
126 unsigned long *get_mask;
127 unsigned long *set_mask;
128 unsigned long invert_mask[];
129 };
130
131 #define for_each_gpio_desc(gc, desc) \
132 for (unsigned int __i = 0; \
133 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
134 __i++) \
135
136 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
137 for_each_gpio_desc(gc, desc) \
138 if (!test_bit(flag, &desc->flags)) {} else
139
140 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
141 unsigned int array_size,
142 struct gpio_desc **desc_array,
143 struct gpio_array *array_info,
144 unsigned long *value_bitmap);
145 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
146 unsigned int array_size,
147 struct gpio_desc **desc_array,
148 struct gpio_array *array_info,
149 unsigned long *value_bitmap);
150
151 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
152
153 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
154
155 struct gpio_desc_label {
156 struct rcu_head rh;
157 char str[];
158 };
159
160 /**
161 * struct gpio_desc - Opaque descriptor for a GPIO
162 *
163 * @gdev: Pointer to the parent GPIO device
164 * @flags: Binary descriptor flags
165 * @label: Name of the consumer
166 * @name: Line name
167 * @hog: Pointer to the device node that hogs this line (if any)
168 *
169 * These are obtained using gpiod_get() and are preferable to the old
170 * integer-based handles.
171 *
172 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
173 * valid until the GPIO is released.
174 */
175 struct gpio_desc {
176 struct gpio_device *gdev;
177 unsigned long flags;
178 /* flag symbols are bit numbers */
179 #define FLAG_REQUESTED 0
180 #define FLAG_IS_OUT 1
181 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
182 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
183 #define FLAG_ACTIVE_LOW 6 /* value has active low */
184 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
185 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
186 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
187 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
188 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
189 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
190 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
191 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
192 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
193 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
194 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
195 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
196 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
197
198 /* Connection label */
199 struct gpio_desc_label __rcu *label;
200 /* Name of the GPIO */
201 const char *name;
202 #ifdef CONFIG_OF_DYNAMIC
203 struct device_node *hog;
204 #endif
205 };
206
207 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
208
209 struct gpio_chip_guard {
210 struct gpio_device *gdev;
211 struct gpio_chip *gc;
212 int idx;
213 };
214
215 DEFINE_CLASS(gpio_chip_guard,
216 struct gpio_chip_guard,
217 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
218 ({
219 struct gpio_chip_guard _guard;
220
221 _guard.gdev = desc->gdev;
222 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
223 _guard.gc = srcu_dereference(_guard.gdev->chip,
224 &_guard.gdev->srcu);
225
226 _guard;
227 }),
228 struct gpio_desc *desc)
229
230 int gpiod_request(struct gpio_desc *desc, const char *label);
231 void gpiod_free(struct gpio_desc *desc);
232
gpiod_request_user(struct gpio_desc * desc,const char * label)233 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
234 {
235 int ret;
236
237 ret = gpiod_request(desc, label);
238 if (ret == -EPROBE_DEFER)
239 ret = -ENODEV;
240
241 return ret;
242 }
243
244 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
245 struct fwnode_handle *fwnode,
246 const char *con_id,
247 unsigned int idx,
248 enum gpiod_flags flags,
249 const char *label,
250 bool platform_lookup_allowed);
251
252 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
253 unsigned long lflags, enum gpiod_flags dflags);
254 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
255 int gpiod_hog(struct gpio_desc *desc, const char *name,
256 unsigned long lflags, enum gpiod_flags dflags);
257 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
258 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
259 const char *gpiod_get_label(struct gpio_desc *desc);
260
261 /*
262 * Return the GPIO number of the passed descriptor relative to its chip
263 */
gpio_chip_hwgpio(const struct gpio_desc * desc)264 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
265 {
266 return desc - &desc->gdev->descs[0];
267 }
268
269 /* With descriptor prefix */
270
271 #define gpiod_err(desc, fmt, ...) \
272 do { \
273 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
274 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
275 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
276 } \
277 } while (0)
278
279 #define gpiod_warn(desc, fmt, ...) \
280 do { \
281 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
282 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
283 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
284 } \
285 } while (0)
286
287 #define gpiod_dbg(desc, fmt, ...) \
288 do { \
289 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
290 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
291 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
292 } \
293 } while (0)
294
295 /* With chip prefix */
296
297 #define chip_err(gc, fmt, ...) \
298 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
299 #define chip_warn(gc, fmt, ...) \
300 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
301 #define chip_info(gc, fmt, ...) \
302 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
303 #define chip_dbg(gc, fmt, ...) \
304 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
305
306 #endif /* GPIOLIB_H */
307