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 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 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned 37 * at device creation time. 38 * @label: a descriptive name for the GPIO device, such as the part number 39 * or name of the IP component in a System on Chip. 40 * @data: per-instance data assigned by the driver 41 * @list: links gpio_device:s together for traversal 42 * @line_state_notifier: used to notify subscribers about lines being 43 * requested, released or reconfigured 44 * @device_notifier: used to notify character device wait queues about the GPIO 45 * device being unregistered 46 * @sem: protects the structure from a NULL-pointer dereference of @chip by 47 * user-space operations when the device gets unregistered during 48 * a hot-unplug event 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 *chip; 63 struct gpio_desc *descs; 64 int base; 65 u16 ngpio; 66 const char *label; 67 void *data; 68 struct list_head list; 69 struct blocking_notifier_head line_state_notifier; 70 struct blocking_notifier_head device_notifier; 71 struct rw_semaphore sem; 72 73 #ifdef CONFIG_PINCTRL 74 /* 75 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 76 * describe the actual pin range which they serve in an SoC. This 77 * information would be used by pinctrl subsystem to configure 78 * corresponding pins for gpio usage. 79 */ 80 struct list_head pin_ranges; 81 #endif 82 }; 83 84 static inline struct gpio_device *to_gpio_device(struct device *dev) 85 { 86 return container_of(dev, struct gpio_device, dev); 87 } 88 89 /* gpio suffixes used for ACPI and device tree lookup */ 90 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; 91 92 /** 93 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes 94 * 95 * @desc: Array of pointers to the GPIO descriptors 96 * @size: Number of elements in desc 97 * @chip: Parent GPIO chip 98 * @get_mask: Get mask used in fastpath 99 * @set_mask: Set mask used in fastpath 100 * @invert_mask: Invert mask used in fastpath 101 * 102 * This structure is attached to struct gpiod_descs obtained from 103 * gpiod_get_array() and can be passed back to get/set array functions in order 104 * to activate fast processing path if applicable. 105 */ 106 struct gpio_array { 107 struct gpio_desc **desc; 108 unsigned int size; 109 struct gpio_chip *chip; 110 unsigned long *get_mask; 111 unsigned long *set_mask; 112 unsigned long invert_mask[]; 113 }; 114 115 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); 116 117 #define for_each_gpio_desc(gc, desc) \ 118 for (unsigned int __i = 0; \ 119 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ 120 __i++) \ 121 122 #define for_each_gpio_desc_with_flag(gc, desc, flag) \ 123 for_each_gpio_desc(gc, desc) \ 124 if (!test_bit(flag, &desc->flags)) {} else 125 126 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 127 unsigned int array_size, 128 struct gpio_desc **desc_array, 129 struct gpio_array *array_info, 130 unsigned long *value_bitmap); 131 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 132 unsigned int array_size, 133 struct gpio_desc **desc_array, 134 struct gpio_array *array_info, 135 unsigned long *value_bitmap); 136 137 extern spinlock_t gpio_lock; 138 extern struct list_head gpio_devices; 139 140 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); 141 142 /** 143 * struct gpio_desc - Opaque descriptor for a GPIO 144 * 145 * @gdev: Pointer to the parent GPIO device 146 * @flags: Binary descriptor flags 147 * @label: Name of the consumer 148 * @name: Line name 149 * @hog: Pointer to the device node that hogs this line (if any) 150 * @debounce_period_us: Debounce period in microseconds 151 * 152 * These are obtained using gpiod_get() and are preferable to the old 153 * integer-based handles. 154 * 155 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 156 * valid until the GPIO is released. 157 */ 158 struct gpio_desc { 159 struct gpio_device *gdev; 160 unsigned long flags; 161 /* flag symbols are bit numbers */ 162 #define FLAG_REQUESTED 0 163 #define FLAG_IS_OUT 1 164 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ 165 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ 166 #define FLAG_ACTIVE_LOW 6 /* value has active low */ 167 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ 168 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ 169 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 170 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 171 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ 172 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 173 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 174 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 175 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 176 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 177 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 178 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 179 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 180 181 /* Connection label */ 182 const char *label; 183 /* Name of the GPIO */ 184 const char *name; 185 #ifdef CONFIG_OF_DYNAMIC 186 struct device_node *hog; 187 #endif 188 #ifdef CONFIG_GPIO_CDEV 189 /* debounce period in microseconds */ 190 unsigned int debounce_period_us; 191 #endif 192 }; 193 194 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 195 196 int gpiod_request(struct gpio_desc *desc, const char *label); 197 void gpiod_free(struct gpio_desc *desc); 198 199 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 200 { 201 int ret; 202 203 ret = gpiod_request(desc, label); 204 if (ret == -EPROBE_DEFER) 205 ret = -ENODEV; 206 207 return ret; 208 } 209 210 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 211 unsigned long lflags, enum gpiod_flags dflags); 212 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 213 int gpiod_hog(struct gpio_desc *desc, const char *name, 214 unsigned long lflags, enum gpiod_flags dflags); 215 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); 216 217 /* 218 * Return the GPIO number of the passed descriptor relative to its chip 219 */ 220 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) 221 { 222 return desc - &desc->gdev->descs[0]; 223 } 224 225 /* With descriptor prefix */ 226 227 #define gpiod_emerg(desc, fmt, ...) \ 228 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 229 ##__VA_ARGS__) 230 #define gpiod_crit(desc, fmt, ...) \ 231 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 232 ##__VA_ARGS__) 233 #define gpiod_err(desc, fmt, ...) \ 234 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 235 ##__VA_ARGS__) 236 #define gpiod_warn(desc, fmt, ...) \ 237 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 238 ##__VA_ARGS__) 239 #define gpiod_info(desc, fmt, ...) \ 240 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 241 ##__VA_ARGS__) 242 #define gpiod_dbg(desc, fmt, ...) \ 243 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 244 ##__VA_ARGS__) 245 246 /* With chip prefix */ 247 248 #define chip_emerg(gc, fmt, ...) \ 249 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 250 #define chip_crit(gc, fmt, ...) \ 251 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 252 #define chip_err(gc, fmt, ...) \ 253 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 254 #define chip_warn(gc, fmt, ...) \ 255 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 256 #define chip_info(gc, fmt, ...) \ 257 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 258 #define chip_dbg(gc, fmt, ...) \ 259 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 260 261 #endif /* GPIOLIB_H */ 262