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