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/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 * @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 * @device_notifier: used to notify character device wait queues about the GPIO
49 * device being unregistered
50 * @srcu: protects the pointer to the underlying GPIO chip
51 * @pin_ranges: range of pins served by the GPIO driver
52 *
53 * This state container holds most of the runtime variable data
54 * for a GPIO device and can hold references and live on after the
55 * GPIO chip has been removed, if it is still being used from
56 * userspace.
57 */
58 struct gpio_device {
59 struct device dev;
60 struct cdev chrdev;
61 int id;
62 struct device *mockdev;
63 struct module *owner;
64 struct gpio_chip __rcu *chip;
65 struct gpio_desc *descs;
66 struct srcu_struct desc_srcu;
67 unsigned int base;
68 u16 ngpio;
69 bool can_sleep;
70 const char *label;
71 void *data;
72 struct list_head list;
73 struct blocking_notifier_head line_state_notifier;
74 struct blocking_notifier_head device_notifier;
75 struct srcu_struct srcu;
76
77 #ifdef CONFIG_PINCTRL
78 /*
79 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
80 * describe the actual pin range which they serve in an SoC. This
81 * information would be used by pinctrl subsystem to configure
82 * corresponding pins for gpio usage.
83 */
84 struct list_head pin_ranges;
85 #endif
86 ANDROID_KABI_RESERVE(1);
87 };
88
to_gpio_device(struct device * dev)89 static inline struct gpio_device *to_gpio_device(struct device *dev)
90 {
91 return container_of(dev, struct gpio_device, dev);
92 }
93
94 /* GPIO suffixes used for ACPI and device tree lookup */
95 extern const char *const gpio_suffixes[];
96
97 #define for_each_gpio_property_name(propname, con_id) \
98 for (const char * const *__suffixes = gpio_suffixes; \
99 *__suffixes && ({ \
100 const char *__gs = *__suffixes; \
101 \
102 if (con_id) \
103 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \
104 else \
105 snprintf(propname, sizeof(propname), "%s", __gs); \
106 1; \
107 }); \
108 __suffixes++)
109
110 /**
111 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
112 *
113 * @desc: Array of pointers to the GPIO descriptors
114 * @size: Number of elements in desc
115 * @chip: Parent GPIO chip
116 * @get_mask: Get mask used in fastpath
117 * @set_mask: Set mask used in fastpath
118 * @invert_mask: Invert mask used in fastpath
119 *
120 * This structure is attached to struct gpiod_descs obtained from
121 * gpiod_get_array() and can be passed back to get/set array functions in order
122 * to activate fast processing path if applicable.
123 */
124 struct gpio_array {
125 struct gpio_desc **desc;
126 unsigned int size;
127 struct gpio_chip *chip;
128 unsigned long *get_mask;
129 unsigned long *set_mask;
130 ANDROID_KABI_RESERVE(1);
131 unsigned long invert_mask[];
132 };
133
134 #define for_each_gpio_desc(gc, desc) \
135 for (unsigned int __i = 0; \
136 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \
137 __i++) \
138
139 #define for_each_gpio_desc_with_flag(gc, desc, flag) \
140 for_each_gpio_desc(gc, desc) \
141 if (!test_bit(flag, &desc->flags)) {} else
142
143 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
144 unsigned int array_size,
145 struct gpio_desc **desc_array,
146 struct gpio_array *array_info,
147 unsigned long *value_bitmap);
148 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
149 unsigned int array_size,
150 struct gpio_desc **desc_array,
151 struct gpio_array *array_info,
152 unsigned long *value_bitmap);
153
154 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
155
156 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
157
158 struct gpio_desc_label {
159 struct rcu_head rh;
160 char str[];
161 };
162
163 /**
164 * struct gpio_desc - Opaque descriptor for a GPIO
165 *
166 * @gdev: Pointer to the parent GPIO device
167 * @flags: Binary descriptor flags
168 * @label: Name of the consumer
169 * @name: Line name
170 * @hog: Pointer to the device node that hogs this line (if any)
171 *
172 * These are obtained using gpiod_get() and are preferable to the old
173 * integer-based handles.
174 *
175 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
176 * valid until the GPIO is released.
177 */
178 struct gpio_desc {
179 struct gpio_device *gdev;
180 unsigned long flags;
181 /* flag symbols are bit numbers */
182 #define FLAG_REQUESTED 0
183 #define FLAG_IS_OUT 1
184 #define FLAG_EXPORT 2 /* protected by sysfs_lock */
185 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
186 #define FLAG_ACTIVE_LOW 6 /* value has active low */
187 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
188 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
189 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
190 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
191 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
192 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
193 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
194 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
195 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
196 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */
197 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */
198 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */
199 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */
200
201 /* Connection label */
202 struct gpio_desc_label __rcu *label;
203 /* Name of the GPIO */
204 const char *name;
205 #ifdef CONFIG_OF_DYNAMIC
206 struct device_node *hog;
207 #endif
208 ANDROID_KABI_RESERVE(1);
209 };
210
211 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
212
213 struct gpio_chip_guard {
214 struct gpio_device *gdev;
215 struct gpio_chip *gc;
216 int idx;
217 };
218
219 DEFINE_CLASS(gpio_chip_guard,
220 struct gpio_chip_guard,
221 srcu_read_unlock(&_T.gdev->srcu, _T.idx),
222 ({
223 struct gpio_chip_guard _guard;
224
225 _guard.gdev = desc->gdev;
226 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
227 _guard.gc = srcu_dereference(_guard.gdev->chip,
228 &_guard.gdev->srcu);
229
230 _guard;
231 }),
232 struct gpio_desc *desc)
233
234 int gpiod_request(struct gpio_desc *desc, const char *label);
235 void gpiod_free(struct gpio_desc *desc);
236
gpiod_request_user(struct gpio_desc * desc,const char * label)237 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
238 {
239 int ret;
240
241 ret = gpiod_request(desc, label);
242 if (ret == -EPROBE_DEFER)
243 ret = -ENODEV;
244
245 return ret;
246 }
247
248 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
249 struct fwnode_handle *fwnode,
250 const char *con_id,
251 unsigned int idx,
252 enum gpiod_flags flags,
253 const char *label,
254 bool platform_lookup_allowed);
255
256 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
257 unsigned long lflags, enum gpiod_flags dflags);
258 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
259 int gpiod_hog(struct gpio_desc *desc, const char *name,
260 unsigned long lflags, enum gpiod_flags dflags);
261 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
262 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
263 const char *gpiod_get_label(struct gpio_desc *desc);
264
265 /*
266 * Return the GPIO number of the passed descriptor relative to its chip
267 */
gpio_chip_hwgpio(const struct gpio_desc * desc)268 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
269 {
270 return desc - &desc->gdev->descs[0];
271 }
272
273 /* With descriptor prefix */
274
275 #define gpiod_err(desc, fmt, ...) \
276 do { \
277 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
278 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
279 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
280 } \
281 } while (0)
282
283 #define gpiod_warn(desc, fmt, ...) \
284 do { \
285 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
286 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
287 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
288 } \
289 } while (0)
290
291 #define gpiod_dbg(desc, fmt, ...) \
292 do { \
293 scoped_guard(srcu, &desc->gdev->desc_srcu) { \
294 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
295 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
296 } \
297 } while (0)
298
299 /* With chip prefix */
300
301 #define chip_err(gc, fmt, ...) \
302 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
303 #define chip_warn(gc, fmt, ...) \
304 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
305 #define chip_info(gc, fmt, ...) \
306 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
307 #define chip_dbg(gc, fmt, ...) \
308 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
309
310 #endif /* GPIOLIB_H */
311