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/gpio/driver.h> 13 #include <linux/gpio/consumer.h> /* for enum gpiod_flags */ 14 #include <linux/err.h> 15 #include <linux/device.h> 16 #include <linux/module.h> 17 #include <linux/cdev.h> 18 #include <linux/rwsem.h> 19 20 #define GPIOCHIP_NAME "gpiochip" 21 22 /** 23 * struct gpio_device - internal state container for GPIO devices 24 * @dev: the GPIO device struct 25 * @chrdev: character device for the GPIO device 26 * @id: numerical ID number for the GPIO chip 27 * @mockdev: class device used by the deprecated sysfs interface (may be 28 * NULL) 29 * @owner: helps prevent removal of modules exporting active GPIOs 30 * @chip: pointer to the corresponding gpiochip, holding static 31 * data for this device 32 * @descs: array of ngpio descriptors. 33 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size 34 * of the @descs array. 35 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned 36 * at device creation time. 37 * @label: a descriptive name for the GPIO device, such as the part number 38 * or name of the IP component in a System on Chip. 39 * @data: per-instance data assigned by the driver 40 * @list: links gpio_device:s together for traversal 41 * @notifier: used to notify subscribers about lines being requested, released 42 * or reconfigured 43 * @sem: protects the structure from a NULL-pointer dereference of @chip by 44 * user-space operations when the device gets unregistered during 45 * a hot-unplug event 46 * @pin_ranges: range of pins served by the GPIO driver 47 * 48 * This state container holds most of the runtime variable data 49 * for a GPIO device and can hold references and live on after the 50 * GPIO chip has been removed, if it is still being used from 51 * userspace. 52 */ 53 struct gpio_device { 54 struct device dev; 55 struct cdev chrdev; 56 int id; 57 struct device *mockdev; 58 struct module *owner; 59 struct gpio_chip *chip; 60 struct gpio_desc *descs; 61 int base; 62 u16 ngpio; 63 const char *label; 64 void *data; 65 struct list_head list; 66 struct blocking_notifier_head notifier; 67 struct rw_semaphore sem; 68 69 #ifdef CONFIG_PINCTRL 70 /* 71 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 72 * describe the actual pin range which they serve in an SoC. This 73 * information would be used by pinctrl subsystem to configure 74 * corresponding pins for gpio usage. 75 */ 76 struct list_head pin_ranges; 77 #endif 78 }; 79 80 static inline struct gpio_device *to_gpio_device(struct device *dev) 81 { 82 return container_of(dev, struct gpio_device, dev); 83 } 84 85 static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev) 86 { 87 return to_gpio_device(get_device(&gdev->dev)); 88 } 89 90 static inline void gpio_device_put(struct gpio_device *gdev) 91 { 92 put_device(&gdev->dev); 93 } 94 95 /* gpio suffixes used for ACPI and device tree lookup */ 96 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; 97 98 /** 99 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes 100 * 101 * @desc: Array of pointers to the GPIO descriptors 102 * @size: Number of elements in desc 103 * @chip: Parent GPIO chip 104 * @get_mask: Get mask used in fastpath 105 * @set_mask: Set mask used in fastpath 106 * @invert_mask: Invert mask used in fastpath 107 * 108 * This structure is attached to struct gpiod_descs obtained from 109 * gpiod_get_array() and can be passed back to get/set array functions in order 110 * to activate fast processing path if applicable. 111 */ 112 struct gpio_array { 113 struct gpio_desc **desc; 114 unsigned int size; 115 struct gpio_chip *chip; 116 unsigned long *get_mask; 117 unsigned long *set_mask; 118 unsigned long invert_mask[]; 119 }; 120 121 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); 122 123 #define for_each_gpio_desc(gc, desc) \ 124 for (unsigned int __i = 0; \ 125 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ 126 __i++) \ 127 128 #define for_each_gpio_desc_with_flag(gc, desc, flag) \ 129 for_each_gpio_desc(gc, desc) \ 130 if (!test_bit(flag, &desc->flags)) {} else 131 132 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 133 unsigned int array_size, 134 struct gpio_desc **desc_array, 135 struct gpio_array *array_info, 136 unsigned long *value_bitmap); 137 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 138 unsigned int array_size, 139 struct gpio_desc **desc_array, 140 struct gpio_array *array_info, 141 unsigned long *value_bitmap); 142 143 extern spinlock_t gpio_lock; 144 extern struct list_head gpio_devices; 145 146 147 /** 148 * struct gpio_desc - Opaque descriptor for a GPIO 149 * 150 * @gdev: Pointer to the parent GPIO device 151 * @flags: Binary descriptor flags 152 * @label: Name of the consumer 153 * @name: Line name 154 * @hog: Pointer to the device node that hogs this line (if any) 155 * @debounce_period_us: Debounce period in microseconds 156 * 157 * These are obtained using gpiod_get() and are preferable to the old 158 * integer-based handles. 159 * 160 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 161 * valid until the GPIO is released. 162 */ 163 struct gpio_desc { 164 struct gpio_device *gdev; 165 unsigned long flags; 166 /* flag symbols are bit numbers */ 167 #define FLAG_REQUESTED 0 168 #define FLAG_IS_OUT 1 169 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ 170 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ 171 #define FLAG_ACTIVE_LOW 6 /* value has active low */ 172 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ 173 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ 174 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 175 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 176 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ 177 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 178 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 179 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 180 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 181 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 182 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 183 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 184 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 185 186 /* Connection label */ 187 const char *label; 188 /* Name of the GPIO */ 189 const char *name; 190 #ifdef CONFIG_OF_DYNAMIC 191 struct device_node *hog; 192 #endif 193 #ifdef CONFIG_GPIO_CDEV 194 /* debounce period in microseconds */ 195 unsigned int debounce_period_us; 196 #endif 197 }; 198 199 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 200 201 int gpiod_request(struct gpio_desc *desc, const char *label); 202 void gpiod_free(struct gpio_desc *desc); 203 204 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 205 { 206 int ret; 207 208 ret = gpiod_request(desc, label); 209 if (ret == -EPROBE_DEFER) 210 ret = -ENODEV; 211 212 return ret; 213 } 214 215 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 216 unsigned long lflags, enum gpiod_flags dflags); 217 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 218 int gpiod_hog(struct gpio_desc *desc, const char *name, 219 unsigned long lflags, enum gpiod_flags dflags); 220 221 /* 222 * Return the GPIO number of the passed descriptor relative to its chip 223 */ 224 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) 225 { 226 return desc - &desc->gdev->descs[0]; 227 } 228 229 /* With descriptor prefix */ 230 231 #define gpiod_emerg(desc, fmt, ...) \ 232 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 233 ##__VA_ARGS__) 234 #define gpiod_crit(desc, fmt, ...) \ 235 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 236 ##__VA_ARGS__) 237 #define gpiod_err(desc, fmt, ...) \ 238 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 239 ##__VA_ARGS__) 240 #define gpiod_warn(desc, fmt, ...) \ 241 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 242 ##__VA_ARGS__) 243 #define gpiod_info(desc, fmt, ...) \ 244 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ 245 ##__VA_ARGS__) 246 #define gpiod_dbg(desc, fmt, ...) \ 247 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ 248 ##__VA_ARGS__) 249 250 /* With chip prefix */ 251 252 #define chip_emerg(gc, fmt, ...) \ 253 dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 254 #define chip_crit(gc, fmt, ...) \ 255 dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 256 #define chip_err(gc, fmt, ...) \ 257 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 258 #define chip_warn(gc, fmt, ...) \ 259 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 260 #define chip_info(gc, fmt, ...) \ 261 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 262 #define chip_dbg(gc, fmt, ...) \ 263 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 264 265 #endif /* GPIOLIB_H */ 266