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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/rwsem.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  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
36  * of the @descs array.
37  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
38  * at device creation time.
39  * @label: a descriptive name for the GPIO device, such as the part number
40  * or name of the IP component in a System on Chip.
41  * @data: per-instance data assigned by the driver
42  * @list: links gpio_device:s together for traversal
43  * @line_state_notifier: used to notify subscribers about lines being
44  *                       requested, released or reconfigured
45  * @device_notifier: used to notify character device wait queues about the GPIO
46  *                   device being unregistered
47  * @sem: protects the structure from a NULL-pointer dereference of @chip by
48  *       user-space operations when the device gets unregistered during
49  *       a hot-unplug event
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	*chip;
64 	struct gpio_desc	*descs;
65 	int			base;
66 	u16			ngpio;
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 rw_semaphore	sem;
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 	ANDROID_KABI_RESERVE(1);
84 };
85 
to_gpio_device(struct device * dev)86 static inline struct gpio_device *to_gpio_device(struct device *dev)
87 {
88 	return container_of(dev, struct gpio_device, dev);
89 }
90 
91 /* gpio suffixes used for ACPI and device tree lookup */
92 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
93 
94 /**
95  * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
96  *
97  * @desc:		Array of pointers to the GPIO descriptors
98  * @size:		Number of elements in desc
99  * @chip:		Parent GPIO chip
100  * @get_mask:		Get mask used in fastpath
101  * @set_mask:		Set mask used in fastpath
102  * @invert_mask:	Invert mask used in fastpath
103  *
104  * This structure is attached to struct gpiod_descs obtained from
105  * gpiod_get_array() and can be passed back to get/set array functions in order
106  * to activate fast processing path if applicable.
107  */
108 struct gpio_array {
109 	struct gpio_desc	**desc;
110 	unsigned int		size;
111 	struct gpio_chip	*chip;
112 	unsigned long		*get_mask;
113 	unsigned long		*set_mask;
114 	ANDROID_KABI_RESERVE(1);
115 	unsigned long		invert_mask[];
116 };
117 
118 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
119 
120 #define for_each_gpio_desc(gc, desc)					\
121 	for (unsigned int __i = 0;					\
122 	     __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i));	\
123 	     __i++)							\
124 
125 #define for_each_gpio_desc_with_flag(gc, desc, flag)			\
126 	for_each_gpio_desc(gc, desc)					\
127 		if (!test_bit(flag, &desc->flags)) {} else
128 
129 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
130 				  unsigned int array_size,
131 				  struct gpio_desc **desc_array,
132 				  struct gpio_array *array_info,
133 				  unsigned long *value_bitmap);
134 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
135 				  unsigned int array_size,
136 				  struct gpio_desc **desc_array,
137 				  struct gpio_array *array_info,
138 				  unsigned long *value_bitmap);
139 
140 extern spinlock_t gpio_lock;
141 extern struct list_head gpio_devices;
142 
143 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
144 
145 /**
146  * struct gpio_desc - Opaque descriptor for a GPIO
147  *
148  * @gdev:		Pointer to the parent GPIO device
149  * @flags:		Binary descriptor flags
150  * @label:		Name of the consumer
151  * @name:		Line name
152  * @hog:		Pointer to the device node that hogs this line (if any)
153  * @debounce_period_us:	Debounce period in microseconds
154  *
155  * These are obtained using gpiod_get() and are preferable to the old
156  * integer-based handles.
157  *
158  * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
159  * valid until the GPIO is released.
160  */
161 struct gpio_desc {
162 	struct gpio_device	*gdev;
163 	unsigned long		flags;
164 /* flag symbols are bit numbers */
165 #define FLAG_REQUESTED	0
166 #define FLAG_IS_OUT	1
167 #define FLAG_EXPORT	2	/* protected by sysfs_lock */
168 #define FLAG_SYSFS	3	/* exported via /sys/class/gpio/control */
169 #define FLAG_ACTIVE_LOW	6	/* value has active low */
170 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
171 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
172 #define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
173 #define FLAG_IRQ_IS_ENABLED 10	/* GPIO is connected to an enabled IRQ */
174 #define FLAG_IS_HOGGED	11	/* GPIO is hogged */
175 #define FLAG_TRANSITORY 12	/* GPIO may lose value in sleep or reset */
176 #define FLAG_PULL_UP    13	/* GPIO has pull up enabled */
177 #define FLAG_PULL_DOWN  14	/* GPIO has pull down enabled */
178 #define FLAG_BIAS_DISABLE    15	/* GPIO has pull disabled */
179 #define FLAG_EDGE_RISING     16	/* GPIO CDEV detects rising edge events */
180 #define FLAG_EDGE_FALLING    17	/* GPIO CDEV detects falling edge events */
181 #define FLAG_EVENT_CLOCK_REALTIME	18 /* GPIO CDEV reports REALTIME timestamps in events */
182 #define FLAG_EVENT_CLOCK_HTE		19 /* GPIO CDEV reports hardware timestamps in events */
183 
184 	/* Connection label */
185 	const char		*label;
186 	/* Name of the GPIO */
187 	const char		*name;
188 #ifdef CONFIG_OF_DYNAMIC
189 	struct device_node	*hog;
190 #endif
191 #ifdef CONFIG_GPIO_CDEV
192 	/* debounce period in microseconds */
193 	unsigned int		debounce_period_us;
194 #endif
195 	ANDROID_KABI_RESERVE(1);
196 };
197 
198 #define gpiod_not_found(desc)		(IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
199 
200 int gpiod_request(struct gpio_desc *desc, const char *label);
201 void gpiod_free(struct gpio_desc *desc);
202 
gpiod_request_user(struct gpio_desc * desc,const char * label)203 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
204 {
205 	int ret;
206 
207 	ret = gpiod_request(desc, label);
208 	if (ret == -EPROBE_DEFER)
209 		ret = -ENODEV;
210 
211 	return ret;
212 }
213 
214 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
215 					 struct fwnode_handle *fwnode,
216 					 const char *con_id,
217 					 unsigned int idx,
218 					 enum gpiod_flags flags,
219 					 const char *label,
220 					 bool platform_lookup_allowed);
221 
222 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
223 		unsigned long lflags, enum gpiod_flags dflags);
224 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
225 int gpiod_hog(struct gpio_desc *desc, const char *name,
226 		unsigned long lflags, enum gpiod_flags dflags);
227 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
228 
229 /*
230  * Return the GPIO number of the passed descriptor relative to its chip
231  */
gpio_chip_hwgpio(const struct gpio_desc * desc)232 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
233 {
234 	return desc - &desc->gdev->descs[0];
235 }
236 
237 /* With descriptor prefix */
238 
239 #define gpiod_emerg(desc, fmt, ...)					       \
240 	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
241 		 ##__VA_ARGS__)
242 #define gpiod_crit(desc, fmt, ...)					       \
243 	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
244 		 ##__VA_ARGS__)
245 #define gpiod_err(desc, fmt, ...)					       \
246 	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
247 		 ##__VA_ARGS__)
248 #define gpiod_warn(desc, fmt, ...)					       \
249 	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
250 		 ##__VA_ARGS__)
251 #define gpiod_info(desc, fmt, ...)					       \
252 	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
253 		 ##__VA_ARGS__)
254 #define gpiod_dbg(desc, fmt, ...)					       \
255 	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
256 		 ##__VA_ARGS__)
257 
258 /* With chip prefix */
259 
260 #define chip_emerg(gc, fmt, ...)					\
261 	dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
262 #define chip_crit(gc, fmt, ...)					\
263 	dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
264 #define chip_err(gc, fmt, ...)					\
265 	dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
266 #define chip_warn(gc, fmt, ...)					\
267 	dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
268 #define chip_info(gc, fmt, ...)					\
269 	dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
270 #define chip_dbg(gc, fmt, ...)					\
271 	dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
272 
273 #endif /* GPIOLIB_H */
274