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 * @notifier: used to notify subscribers about lines being requested, released 43 * or reconfigured 44 * @sem: protects the structure from a NULL-pointer dereference of @chip by 45 * user-space operations when the device gets unregistered during 46 * a hot-unplug event 47 * @pin_ranges: range of pins served by the GPIO driver 48 * 49 * This state container holds most of the runtime variable data 50 * for a GPIO device and can hold references and live on after the 51 * GPIO chip has been removed, if it is still being used from 52 * userspace. 53 */ 54 struct gpio_device { 55 struct device dev; 56 struct cdev chrdev; 57 int id; 58 struct device *mockdev; 59 struct module *owner; 60 struct gpio_chip *chip; 61 struct gpio_desc *descs; 62 int base; 63 u16 ngpio; 64 const char *label; 65 void *data; 66 struct list_head list; 67 struct blocking_notifier_head notifier; 68 struct rw_semaphore sem; 69 70 #ifdef CONFIG_PINCTRL 71 /* 72 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 73 * describe the actual pin range which they serve in an SoC. This 74 * information would be used by pinctrl subsystem to configure 75 * corresponding pins for gpio usage. 76 */ 77 struct list_head pin_ranges; 78 #endif 79 }; 80 81 static inline struct gpio_device *to_gpio_device(struct device *dev) 82 { 83 return container_of(dev, struct gpio_device, dev); 84 } 85 86 static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev) 87 { 88 return to_gpio_device(get_device(&gdev->dev)); 89 } 90 91 static inline void gpio_device_put(struct gpio_device *gdev) 92 { 93 put_device(&gdev->dev); 94 } 95 96 /* gpio suffixes used for ACPI and device tree lookup */ 97 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; 98 99 /** 100 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes 101 * 102 * @desc: Array of pointers to the GPIO descriptors 103 * @size: Number of elements in desc 104 * @chip: Parent GPIO chip 105 * @get_mask: Get mask used in fastpath 106 * @set_mask: Set mask used in fastpath 107 * @invert_mask: Invert mask used in fastpath 108 * 109 * This structure is attached to struct gpiod_descs obtained from 110 * gpiod_get_array() and can be passed back to get/set array functions in order 111 * to activate fast processing path if applicable. 112 */ 113 struct gpio_array { 114 struct gpio_desc **desc; 115 unsigned int size; 116 struct gpio_chip *chip; 117 unsigned long *get_mask; 118 unsigned long *set_mask; 119 unsigned long invert_mask[]; 120 }; 121 122 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); 123 124 #define for_each_gpio_desc(gc, desc) \ 125 for (unsigned int __i = 0; \ 126 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ 127 __i++) \ 128 129 #define for_each_gpio_desc_with_flag(gc, desc, flag) \ 130 for_each_gpio_desc(gc, desc) \ 131 if (!test_bit(flag, &desc->flags)) {} else 132 133 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 134 unsigned int array_size, 135 struct gpio_desc **desc_array, 136 struct gpio_array *array_info, 137 unsigned long *value_bitmap); 138 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 139 unsigned int array_size, 140 struct gpio_desc **desc_array, 141 struct gpio_array *array_info, 142 unsigned long *value_bitmap); 143 144 extern spinlock_t gpio_lock; 145 extern struct list_head gpio_devices; 146 147 148 /** 149 * struct gpio_desc - Opaque descriptor for a GPIO 150 * 151 * @gdev: Pointer to the parent GPIO device 152 * @flags: Binary descriptor flags 153 * @label: Name of the consumer 154 * @name: Line name 155 * @hog: Pointer to the device node that hogs this line (if any) 156 * @debounce_period_us: Debounce period in microseconds 157 * 158 * These are obtained using gpiod_get() and are preferable to the old 159 * integer-based handles. 160 * 161 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 162 * valid until the GPIO is released. 163 */ 164 struct gpio_desc { 165 struct gpio_device *gdev; 166 unsigned long flags; 167 /* flag symbols are bit numbers */ 168 #define FLAG_REQUESTED 0 169 #define FLAG_IS_OUT 1 170 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ 171 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ 172 #define FLAG_ACTIVE_LOW 6 /* value has active low */ 173 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ 174 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ 175 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 176 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 177 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ 178 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 179 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 180 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 181 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 182 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 183 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 184 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 185 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 186 187 /* Connection label */ 188 const char *label; 189 /* Name of the GPIO */ 190 const char *name; 191 #ifdef CONFIG_OF_DYNAMIC 192 struct device_node *hog; 193 #endif 194 #ifdef CONFIG_GPIO_CDEV 195 /* debounce period in microseconds */ 196 unsigned int debounce_period_us; 197 #endif 198 }; 199 200 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 201 202 int gpiod_request(struct gpio_desc *desc, const char *label); 203 void gpiod_free(struct gpio_desc *desc); 204 205 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 206 { 207 int ret; 208 209 ret = gpiod_request(desc, label); 210 if (ret == -EPROBE_DEFER) 211 ret = -ENODEV; 212 213 return ret; 214 } 215 216 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 217 unsigned long lflags, enum gpiod_flags dflags); 218 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 219 int gpiod_hog(struct gpio_desc *desc, const char *name, 220 unsigned long lflags, enum gpiod_flags dflags); 221 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); 222 223 /* 224 * Return the GPIO number of the passed descriptor relative to its chip 225 */ 226 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) 227 { 228 return desc - &desc->gdev->descs[0]; 229 } 230 231 /* With descriptor prefix */ 232 233 #define gpiod_emerg(desc, fmt, ...) \ 234 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 235 ##__VA_ARGS__) 236 #define gpiod_crit(desc, fmt, ...) \ 237 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 238 ##__VA_ARGS__) 239 #define gpiod_err(desc, fmt, ...) \ 240 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 241 ##__VA_ARGS__) 242 #define gpiod_warn(desc, fmt, ...) \ 243 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 244 ##__VA_ARGS__) 245 #define gpiod_info(desc, fmt, ...) \ 246 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 247 ##__VA_ARGS__) 248 #define gpiod_dbg(desc, fmt, ...) \ 249 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 250 ##__VA_ARGS__) 251 252 /* With chip prefix */ 253 254 #define chip_emerg(gc, fmt, ...) \ 255 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 256 #define chip_crit(gc, fmt, ...) \ 257 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 258 #define chip_err(gc, fmt, ...) \ 259 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 260 #define chip_warn(gc, fmt, ...) \ 261 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 262 #define chip_info(gc, fmt, ...) \ 263 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 264 #define chip_dbg(gc, fmt, ...) \ 265 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 266 267 #endif /* GPIOLIB_H */ 268