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/mutex.h> 19 #include <linux/notifier.h> 20 #include <linux/rwsem.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 }; 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 extern spinlock_t gpio_lock; 139 extern struct list_head gpio_devices; 140 extern struct rw_semaphore gpio_devices_sem; 141 142 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); 143 144 /** 145 * struct gpio_desc - Opaque descriptor for a GPIO 146 * 147 * @gdev: Pointer to the parent GPIO device 148 * @flags: Binary descriptor flags 149 * @label: Name of the consumer 150 * @name: Line name 151 * @hog: Pointer to the device node that hogs this line (if any) 152 * 153 * These are obtained using gpiod_get() and are preferable to the old 154 * integer-based handles. 155 * 156 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 157 * valid until the GPIO is released. 158 */ 159 struct gpio_desc { 160 struct gpio_device *gdev; 161 unsigned long flags; 162 /* flag symbols are bit numbers */ 163 #define FLAG_REQUESTED 0 164 #define FLAG_IS_OUT 1 165 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ 166 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ 167 #define FLAG_ACTIVE_LOW 6 /* value has active low */ 168 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ 169 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ 170 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 171 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 172 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ 173 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 174 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 175 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 176 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 177 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 178 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 179 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 180 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 181 182 /* Connection label */ 183 const char *label; 184 /* Name of the GPIO */ 185 const char *name; 186 #ifdef CONFIG_OF_DYNAMIC 187 struct device_node *hog; 188 #endif 189 }; 190 191 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 192 193 int gpiod_request(struct gpio_desc *desc, const char *label); 194 void gpiod_free(struct gpio_desc *desc); 195 196 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 197 { 198 int ret; 199 200 ret = gpiod_request(desc, label); 201 if (ret == -EPROBE_DEFER) 202 ret = -ENODEV; 203 204 return ret; 205 } 206 207 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 208 unsigned long lflags, enum gpiod_flags dflags); 209 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 210 int gpiod_hog(struct gpio_desc *desc, const char *name, 211 unsigned long lflags, enum gpiod_flags dflags); 212 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); 213 214 /* 215 * Return the GPIO number of the passed descriptor relative to its chip 216 */ 217 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) 218 { 219 return desc - &desc->gdev->descs[0]; 220 } 221 222 /* With descriptor prefix */ 223 224 #define gpiod_emerg(desc, fmt, ...) \ 225 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 226 ##__VA_ARGS__) 227 #define gpiod_crit(desc, fmt, ...) \ 228 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 229 ##__VA_ARGS__) 230 #define gpiod_err(desc, fmt, ...) \ 231 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 232 ##__VA_ARGS__) 233 #define gpiod_warn(desc, fmt, ...) \ 234 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 235 ##__VA_ARGS__) 236 #define gpiod_info(desc, fmt, ...) \ 237 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 238 ##__VA_ARGS__) 239 #define gpiod_dbg(desc, fmt, ...) \ 240 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 241 ##__VA_ARGS__) 242 243 /* With chip prefix */ 244 245 #define chip_emerg(gc, fmt, ...) \ 246 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 247 #define chip_crit(gc, fmt, ...) \ 248 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 249 #define chip_err(gc, fmt, ...) \ 250 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 251 #define chip_warn(gc, fmt, ...) \ 252 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 253 #define chip_info(gc, fmt, ...) \ 254 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 255 #define chip_dbg(gc, fmt, ...) \ 256 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 257 258 #endif /* GPIOLIB_H */ 259